Le syndrome de Sézary (SS) est un variant leucémique et érythrodermique de lymphomes T cutanés. Il est caractérisé par la présence d’une population clonale de LT CD4+, présentant un noyau cérébriforme atypique, dans la peau, les ganglions lymphatiques et le sang périphérique. Après un bilan clinique, le diagnostic de cette pathologie est confirmé par l’analyse immunohistochimique d'une biopsie cutanée. Néanmoins, la cytomorphologie des cellules de Sézary circulantes n’est pas uniquement associée au SS. Notre laboratoire a identifié CD158k comme marqueur membranaire spécifique des cellules de Sézary. Ce récepteur offre un intérêt dans le diagnostic du SS et dans le suivi de l’évolution de la pathologie. Ainsi, nos résultats montrent qu’un immuno-marquage CD3+ CD158k+, analysé en cytométrie en flux, est une technique spécifique et sensible de détection de la cellule de Sézary par rapport à la cytomorphologie. Alors que dans plus de 30% des cas le SS passe inaperçu durant l’examen cytomorphologique, une analyse en cytométrie en flux permet la mise en évidence de cellules tumorales résiduelles. La présence systématique de CD158k à la surface des cellules de Sézary nous a conduit à rechercher l’expression d’autres KIRs. Sur les lymphocytes tumoraux circulants d’un patient ainsi que sur la lignée cellulaire correspondante, l’expression des formes activatrices et inhibitrices des récepteurs CD158a/h et CD158b/j est détectée. A la différence des lymphocytes NK et T CD8+, le récepteur présentant une fonction inhibitrice (KIR-L) ne l’emporte pas sur celui ayant une fonction activatrice (KIR-S) dans la cellule de Sézary. En fait, les KIR-L, à l’exception de CD158k, sont trouvés non fonctionnels dans la cellule tumorale. Ainsi, l’engagement des formes activatrices CD158h ou CD158j permet une régulation positive de la voie de signalisation CD3-dépendante de JNK et de la prolifération tumorale. Une étude fonctionnelle de la population T CD4+ KIR+, équivalent normal de la cellule de Sézary, a aussi été réalisée. Nous avons mis en évidence une expression préférentielle de la forme activatrice ou inhibitrice des récepteurs KIR homologues, selon le donneur. D’autre part, les KIRs activateurs ou inhibiteurs, exprimés à la surface des LT CD4+, jouent un rôle de co-récepteur vis-à-vis du TCR. Ainsi, une régulation positive ou négative de la prolifération et de la voie de signalisation CD3-dépendante de ERK est observée en fonction du type de récepteur co-engagé. Il est bien établi que les KIR-S s’associent à la molécule adaptatrice KARAP/DAP12 pour la transduction d’un signal d’activation. Dans les cellules T CD4+ saines et tumorales, la protéine recrutée par ces récepteurs est encore non identifiée. Notre étude sur la population T CD4+ CD158j+ de sujets sains montre l’implication de la protéine HS1 dans la signalisation mise en place par le récepteur KIR activateur. La réalisation de ce travail a permis de mieux comprendre les mécanismes mis en place à partir des KIRs dans les cellules T CD4+. Ce travail ouvre de nouvelles perspectives concernant le rôle de ces récepteurs dans les mécanismes permettant l'expansion tumorale des cellules de Sézary / Sézary syndrome (SS) is a leukemic and erythrodermic variant of cutaneous T-cell lymphomas. It is characterized by the presence of a clonal CD4+ T lymphocyte population in the skin, lymphnodes and peripheral blood. After clinical assessment, diagnosis of this disease is confirmed by immunohistochemistry analysis of a skin biopsy. However, the cytomorphology of circulating Sézary cells is not just associated to SS. Our laboratory has identified CD158k as a phenotypic marker for Sézary cells. This receptor can be used in the diagnosis of the SS and in monitoring the evolution of the disease. Our results show that the CD3/CD158k immunostaining, analysed by flow cytométrie, is more specific and sensitive than cytomorphology to detect atypical circulating cells. While more than 30% of the SS is misdiagnosed by the cytomorphologic identification, flow cytometry analysis allows the detection of residual tumor cells. Given the systemic expression of CD158k on Sézary cells, we next investigated the expression of additional KIRs. On circulating malignant lymphocytes from one patient and the corresponding cell line, the expression of inhibitory and activating forms of CD158a/h and CD158b/j receptors was detected. In contrast to NK cells and CD8+ T lymphocytes, the inhibitory receptor signaling (KIR-L) does not outweigh the activating receptor signaling (KIR-S) in the Sézary cell. In fact, KIR-L, except CD158k, are found not functional in the tumor cell. Thus, CD158h or CD158j engagement results in an enhanced CD3-induced cell proliferation and JNK activation. A functional study of CD4+ KIR+ T lymphocyte population, the normal equivalent of Sézary cells, was then performed. We observed an exclusive expression of the activating or the inhibitory form of KIR receptors, depending on the donor. Activating or inhibitory KIRs, expressed on the CD4+ T cell surface, act as coreceptors. Thus, a positive or negative regulation of the CD3-induced cell proliferation and ERK activation is observed by triggering the KIR-S or -L respectively. It is well known that stimulatory KIR initiates intracellular signals through their association with the adaptor protein KARAP/DAP12. However, in normal and malignant CD4+ T cells the protein recruited by these receptors is still not identified. Our study on CD4+ CD158j+ T lymphocyte population from healthy individuals showed the involvement of HS1 protein as a potential adaptor molecule in the activating KIR signaling pathway. This work has provided insight into the mechanisms of KIRs signaling in CD4+ T cells and opens new perspectives on the role of these receptors in proliferation of Sézary cells

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22341号 / 医博第4582号 / 新制||医||1042(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 髙折 晃史, 教授 羽賀 博典, 教授 伊藤 貴浩 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

La variante lymphocytaire du syndrome hyperéosinophilique (L-SHE) est une pathologie extrêmement rare caractérisée par une prolifération monoclonale de lymphocytes T surproduisant l’interleukine IL-5, responsable d’une hyperéosinophilie persistante. En outre, un immunophénotype aberrant CD3−CD4+ est fréquemment observé à la surface des cellules T clonales. Cette pathologie se distingue par une lymphoprolifération chronique indolente habituellement révélée par une hyperéosinophilie sanguine et une infiltration éosinophilique des tissus cutanés. Toutefois, l’évolution vers un lymphome T observée chez certains patients suggère la présence d’un potentiel malin des cellules T. Ce modèle représente donc une rare opportunité d’identifier les changements moléculaires liés aux différentes étapes du processus transformant lymphoïde T. Dans le cadre de ce travail, nous avons cherché à établir les caractéristiques cytogénétiques et moléculaires des cellules T CD3−CD4+ d’une cohorte de patients L-SHE. L’analyse cytogénétique de cellules T CD3−CD4+ isolées au moment du diagnostic chez deux patientes (P1 et P2) a révélé la présence d’une délétion similaire 6q13-q22.1. En étudiant les stades cliniques successifs de P1 et P2, nous avons montré la persistance des cellules porteuses de la délétion 6q au cours de la progression chronique et leur prédominance lors du développement d’un lymphome T chez P1. Ces résultats suggèrent l’implication précoce et potentiellement critique de la délétion 6q dans cette pathologie lymphoproliférative T. L’analyse des dérégulations transcriptionnelles résultant de ce remaniement a montré une réduction de l’expression des gènes pro-apototiques BACH2 et PA26 dans les cellules T CD3−CD4+ de P1 et P2. En particulier, BACH2, dont l’expression diminue continuellement au cours de l’évolution de P1, jouerait un rôle oncosuppresseur dans la lymphogenèse T. Afin d’identifier les modifications moléculaires des cellules T clonales, nous avons analysé l’expression de 95% des gènes humains dans les cellules T CD3−CD4+ de trois patients en phase chronique (P1, P2 et P3). La grande homologie des changements transcriptionnels chez les trois patients indique une altération des mêmes mécanismes moléculaires. Ainsi, un profil immunophénotypique exhaustif, validé chez trois patients supplémentaires, a pu être établi. En outre, les dérégulations des voies apoptotiques, TGFβ ou 9 encore de signalisation intracellulaire altèrent l’homéostasie des cellules T CD3−CD4+ pouvant favoriser la perte de la capacité apoptotique et/ou la croissance cellulaire. Cette signature moléculaire a été étendue par l’identification de 20 microARNs dont l’expression est dérégulée dans les cellules T CD3−CD4+ d’une cohorte de 6 patients. Par ailleurs, la modification de l’expression des récepteurs impliqués dans la migration leucocytaire au cours de l’évolution de P1 pourrait expliquer l’infiltration ganglionnaire des cellules T clonales et la progression du lymphome. La caractérisation des désordres cytogénétiques et moléculaires des cellules T CD3−CD4+ chez les patients L-SHE permettrait à terme d’identifier de nouveaux marqueurs diagnostiques et contribuer ainsi au développement de nouvelles cibles thérapeutiques dans une grande diversité de pathologies lymphoprolifératives de type Th2.

γδ T cells are unique players in shaping immune responses, lying at the intersection between innate and adaptive immunity. Unlike conventional αβ T cells, γδ T cells largely populate non-lymphoid peripheral tissues, demonstrating tissue specificity, and they respond to ligands in an MHC-independent manner. γδ T cells display rapid activation and effector functions, with a capacity for cytotoxic anti-tumour responses and production of inflammatory cytokines such as IFN-γ or IL-17. Their rapid cytotoxic nature makes them attractive cells for use in anti-cancer immunotherapies. However, upon transformation, γδ T cells can give rise to highly aggressive lymphomas. These rare malignancies often display poor patient survival, and no curative therapies exist. In this review, we discuss the diverse roles of γδ T cells in immune surveillance and response, with a particular focus on cancer immunity. We summarise the intriguing dichotomy between pro- and anti-tumour functions of γδ T cells in solid and haematological cancers, highlighting the key subsets involved. Finally, we discuss potential drivers of γδ T-cell transformation, summarising the main γδ T-cell lymphoma/leukaemia entities, their clinical features, recent advances in mapping their molecular and genomic landscapes, current treatment strategies and potential future targeting options.

Introdução: Micose fungoide poiquilodérmica (MFp) é uma variante clínica de micose fungoide (MF). É mais indolente e caracterizada pela presença da poiquilodermia. As metaloproteinases (MMP) e seus inibidores específicos TIMP (Tissue Inhibitors of Metaloproteinases) estão envolvidos na oncogênese. Especificamente as MMP2 e MMP9 e seus inibidores, TIMP-2 e TIMP-1, respectivamente, foram relacionados ao prognóstico em tumores. Poucos trabalhos estudaram MMP e nenhum estudou a ação dos TIMP na MF. Objetivos: avaliar a relação entre MMP2 e MMP9 e seus inibidores TIMP2 e TIMP1 e a agressividade da MF e descrever a casuística de micose fungoide poiquilodérmica no ambulatório de linfomas cutâneos da Divisão de Clínica Dermatológica do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Métodos: análise retrospectiva de 54 casos de MFp, sendo 25 de MFp localizada 14 de MFp generalizada e 15 de MFp mista. Para análise das MMP e TIMP, os grupos de MFp foram comparados com 7 amostras de pele normal (PN), 10 casos de MF clássica inicial (MFi), 9 casos de MF tumoral não-transformada (MFT nt) e 10 de MF tumoral transformada (MFT t). Resultados: A proporção de mulheres: homens foi 2,44. MFp apresentou maior tempo entre os primeiros sintomas e o diagnóstico. MFpG apresentou maior prevalência de lesões do tipo pitiríase liquenoide crônica (PLC) (79%). Houve alta prevalência de MF hipocromiante (62%) no grupo MFp mista. A histologia da MFp apresentou características típicas de MF e, adicionalmente, atrofia, telangectasias e derrame pigmentar, específicos da forma poiquilodérmica. Na imuno-histoquímica predominou o fenótipo CD3+, CD4+, CD7-, CD8- em todos os grupos, e MFp apresentou significantemente menor predomínio do fenótipo CD8+ que o grupo MFi. O grupo MFpG apresentou baixa positividade para pesquisa de clonalidade T da pele (12,5%). A MMP2 esteve mais presente na epiderme em MFi e MFp relativamente a MFT. Na derme superficial, os grupos MFi e MFp marcaram mais MMP2 que a pele normal, mas sem diferença estatística entre eles. Não houve diferença estatística em MMP2 na derme profunda entre os grupos. À zimografia, houve maior atividade de MMP2 ativa no grupo MFTt. Não houve expressão de TIMP-2 pela epiderme da pele normal. Os grupos MFi e MFp marcaram TIMP-2 na epiderme de forma semelhante, porém menos que os grupos MFT. Na derme superficial, não houve diferença estatística entre os grupos MFi e MFp. TIMP-2 foi mais expresso na derme profunda dos dois grupos de MFT comparativamente a todos os outros grupos. Na epiderme e na derme superficial, MMP9 foi mais expressa no grupo MFi comparativamente a MFp. Na derme profunda, a expressão de MMP9 foi maior nos grupos MFT, seguido por MFi e, por último, MFp. A atividade de MMP9 foi maior no grupo MFT não transformada comparativamente aos outros grupos. TIMP-1, ne epiderme e na derme superficial e na derme profunda foi mais expresso no grupo MFi, comparativamente aos outros grupos. Discussão: MFpG apresentou mais lesões tipo PLC e a forma mista, lesões hipocrômicas. A histologia da MFp foi semelhante à descrita previamente na literatura, mas a baixa positividade de CD8 difere de relatos prévios. A MMP2 pareceu ser um marcador de atividade para MF, principalmente quando a sua presença por imunohistoquímica foi associada a dados de zimografia. A expressão de MMP9 nas amostras foi compatível com os dados prévios de literatura, tendo sido mais expressa nas formas mais agressivas de MF e, histologicamente, mais localizada nos locais de maior atividade do tumor. TIMP-1 foi expresso de forma análoga à MMP9, conforme descrito previamente na literatura. TIMP-2, por sua vez, seguiu o padrão de distribuição de MMP2. No entanto, não foi expresso pela pele normal e foi mais expresso pelos grupos de MFT, o que não ocorreu com a MMP2 na imuno-histoquímica. Conclusões: A expressão de MMP e TIMP correlacionou-se com o local de maior atividade linfocitária e com a agressividade da MF. A atividade da MMP2 e MMP9 foi maior nos grupos MFT comparativamente aos grupos mais indolentes. Separar os casos de MFp de acordo com suas apresentações localizadas, generalizada e mista foi relevante do ponto de vista clínico, laboratorial e evolutivo / Introduction: poikilodermatous mycosis fungoides (pMF) is a clinical variant of mycosis fungoides (MF). It is more indolent than classic MF and is characterized by the presence of poikiloderma. The matrix metalloproteinases (MMPs) and their specific inhibitors TIMP (Tissue Inhibitors of Metalloproteinases) are involved in oncogenesis. Specifically, MMP2 and MMP9 and their inhibitors, TIMP-2 and TIMP-1, respectively, have been related to prognosis in tumors. There are few studies on MMP and none on the role of TIMPs in MF. Objectives: To evaluate if there is a relationship between the presence and activity of MMP2 and MMP9 and their inhibitors TIMP2 and TIMP1, and the aggressiveness of MF. To describe a casuistic of poikilodermatous mycosis fungoides in an outpatient clinic in the Dermatological Division of Hospital das Clinicas of University of Sao Paulo Medical School. Methods: Retrospective analysis of 54 cases of pMF, this included 25 localized pMF (LpMF), 14 generalized pMF (GpMF) and 15 mixed pMF. For the analysis of MMPs and TIMPs, the pMF groups were compared with 7 normal skin samples (NS), 10 cases of initial classical MF (cMF), 9 cases of non-transformed tumor MF (nt MFT) and 10 transformed tumor MF (t MFT). Results: The proportion of women : men was 2.44. The pMFs groups showed a longer period of time from the first symptoms to the diagnosis than the cMF group. The GpMF group had a higher incidence of pityriasis lichenoides chronica-like lesions (PLC) (79%) than the other groups. There was a high incidence of hypopigmented MF (62%) in the mixed pMF group. Histology showed typical characteristics of MF and, additionally, atrophy, telangiectasia and pigmentary alterations compatible with pMF. At immunohistochemistry the cases were predominantly CD3+, CD4+, CD7-, CD8- phenotype in all groups, and the pMF groups had a significantly lower prevalence of CD8+ phenotype than the cMF group. The GPMF group showed low positivity for clonality of the T-cell receptor at the T skin (12.5%) compared to the other groups. The MMP2 was more present in the epidermis for the cMF and pMF groups compared to MFT. In the superficial dermis, the cMF, LpMF and GpMF groups showed more MMP2 than normal skin, however there was no statistical difference between the three groups. There was no statistical difference in the presence of MMP2 in the deep dermis between the groups. The zymography showed higher MMP2 activity in the MFT group. There was no TIMP-2 expression by the normal epidermis. The epidermis of cMF and pMFs groups marked TIMP-2 in a similar way, but at a lower intensity than the MFT groups. In the superficial dermis, there was no statistical difference between the cMF and pMFs groups. TIMP-2 was more expressed in the deep dermis of the two MFT groups compared to all of the other groups. In the epidermis and superficial dermis, the MMP9 was more expressed in cMF compared to pMF groups. In the deep dermis, MMP9 expression was higher in the MFT groups, followed by cMF and finally pMF. The MMP9 activity was higher in the nt MFT group compared to other groups. TIMP-1, in epidermis, superficial dermis and deep dermis was more expressed in the cMF group compared to other groups. Discussion: The study confirmed that the pMF is an indolent form of MF and the time period between the symptoms and the diagnosis in pMF was longer than in classical MF. There were clinical differences amongst the groups of pMF. The GpMF group had a higher prevalence of PLC-like lesions than the mixed form of pMF, which had more hypochromic lesions. Histology of pMF was similar to descriptions provided in other case studies. However, the low CD8 positivity differs from previous reports. The MMP2 appeared to be a marker of activity for MF in our work, especially when their presence by immunohistochemistry was associated with the enzyme activity. The expression of MMP9 in our samples was consistent with previous data from other case studies, being more expressed in the most aggressive forms of MF and histologically more localized in most active sites of the tumor. TIMP-1 was expressed in an analogous manner to MMP9, as previously described in the literature. TIMP-2, in turn, followed the distribution pattern of MMP2. However, it was not expressed by normal skin and was more expressed by the MFT group, which did not occur with the MMP2 in immunohistochemistry. Conclusions: The expression of MMP and TIMP was correlated with the location of higher lymphocyte activity and with the aggressiveness of MF. The activity of MMP2 and MMP9 was higher in the MFT groups than the more indolent groups. It was important to split the pMF cases according to their presentation (GpMF, LpMF and mix pMF) from a clinical, laboratory and prognostic point of view

T-cell receptor (TCR) polyclonal mature T cells are surprisingly resistant to oncogenic transformation after retroviral insertion of T-cell oncogenes. In a mouse model, it has been shown that mature T-cell lymphoma/leukemia (MTCLL) is not induced upon transplantation of mature, TCR polyclonal wild-type (WT) T cells, transduced with gammaretroviral vectors encoding potent T-cell oncogenes, into RAG1-deficient recipients. However, further studies demonstrated that quasi-monoclonal T cells treated with the same protocol readily induced MTCLL in the recipient mice. It has been hypothesized that in the TCR polyclonal situation, outgrowth of preleukemic cells and subsequent conversion to overt malignancy is suppressed through regulation of clonal abundances on a per-clone basis due to interactions between TCRs and self-peptide-MHC-complexes (spMHCs), while these mechanisms fail in the quasi-monoclonal situation. To quantitatively study this hypothesis, we applied a mathematical modeling approach. In particular, we developed a novel ordinary differential equation model of T-cell homeostasis, in which T-cell fate depends on spMHC-TCR-interaction-triggered stimulatory signals from antigen-presenting cells (APCs). Based on our mathematical modeling approach, we identified parameter configurations of our model, which consistently explain the observed phenomena. Our results suggest that the preleukemic cells are less competent than healthy competitor cells in acquiring survival stimuli from APCs, but that proliferation of these preleukemic cells is less dependent on survival stimuli from APCs. These predictions now call for experimental validation.

Introdução: Micose fungoide poiquilodérmica (MFp) é uma variante clínica de micose fungoide (MF). É mais indolente e caracterizada pela presença da poiquilodermia. As metaloproteinases (MMP) e seus inibidores específicos TIMP (Tissue Inhibitors of Metaloproteinases) estão envolvidos na oncogênese. Especificamente as MMP2 e MMP9 e seus inibidores, TIMP-2 e TIMP-1, respectivamente, foram relacionados ao prognóstico em tumores. Poucos trabalhos estudaram MMP e nenhum estudou a ação dos TIMP na MF. Objetivos: avaliar a relação entre MMP2 e MMP9 e seus inibidores TIMP2 e TIMP1 e a agressividade da MF e descrever a casuística de micose fungoide poiquilodérmica no ambulatório de linfomas cutâneos da Divisão de Clínica Dermatológica do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Métodos: análise retrospectiva de 54 casos de MFp, sendo 25 de MFp localizada 14 de MFp generalizada e 15 de MFp mista. Para análise das MMP e TIMP, os grupos de MFp foram comparados com 7 amostras de pele normal (PN), 10 casos de MF clássica inicial (MFi), 9 casos de MF tumoral não-transformada (MFT nt) e 10 de MF tumoral transformada (MFT t). Resultados: A proporção de mulheres: homens foi 2,44. MFp apresentou maior tempo entre os primeiros sintomas e o diagnóstico. MFpG apresentou maior prevalência de lesões do tipo pitiríase liquenoide crônica (PLC) (79%). Houve alta prevalência de MF hipocromiante (62%) no grupo MFp mista. A histologia da MFp apresentou características típicas de MF e, adicionalmente, atrofia, telangectasias e derrame pigmentar, específicos da forma poiquilodérmica. Na imuno-histoquímica predominou o fenótipo CD3+, CD4+, CD7-, CD8- em todos os grupos, e MFp apresentou significantemente menor predomínio do fenótipo CD8+ que o grupo MFi. O grupo MFpG apresentou baixa positividade para pesquisa de clonalidade T da pele (12,5%). A MMP2 esteve mais presente na epiderme em MFi e MFp relativamente a MFT. Na derme superficial, os grupos MFi e MFp marcaram mais MMP2 que a pele normal, mas sem diferença estatística entre eles. Não houve diferença estatística em MMP2 na derme profunda entre os grupos. À zimografia, houve maior atividade de MMP2 ativa no grupo MFTt. Não houve expressão de TIMP-2 pela epiderme da pele normal. Os grupos MFi e MFp marcaram TIMP-2 na epiderme de forma semelhante, porém menos que os grupos MFT. Na derme superficial, não houve diferença estatística entre os grupos MFi e MFp. TIMP-2 foi mais expresso na derme profunda dos dois grupos de MFT comparativamente a todos os outros grupos. Na epiderme e na derme superficial, MMP9 foi mais expressa no grupo MFi comparativamente a MFp. Na derme profunda, a expressão de MMP9 foi maior nos grupos MFT, seguido por MFi e, por último, MFp. A atividade de MMP9 foi maior no grupo MFT não transformada comparativamente aos outros grupos. TIMP-1, ne epiderme e na derme superficial e na derme profunda foi mais expresso no grupo MFi, comparativamente aos outros grupos. Discussão: MFpG apresentou mais lesões tipo PLC e a forma mista, lesões hipocrômicas. A histologia da MFp foi semelhante à descrita previamente na literatura, mas a baixa positividade de CD8 difere de relatos prévios. A MMP2 pareceu ser um marcador de atividade para MF, principalmente quando a sua presença por imunohistoquímica foi associada a dados de zimografia. A expressão de MMP9 nas amostras foi compatível com os dados prévios de literatura, tendo sido mais expressa nas formas mais agressivas de MF e, histologicamente, mais localizada nos locais de maior atividade do tumor. TIMP-1 foi expresso de forma análoga à MMP9, conforme descrito previamente na literatura. TIMP-2, por sua vez, seguiu o padrão de distribuição de MMP2. No entanto, não foi expresso pela pele normal e foi mais expresso pelos grupos de MFT, o que não ocorreu com a MMP2 na imuno-histoquímica. Conclusões: A expressão de MMP e TIMP correlacionou-se com o local de maior atividade linfocitária e com a agressividade da MF. A atividade da MMP2 e MMP9 foi maior nos grupos MFT comparativamente aos grupos mais indolentes. Separar os casos de MFp de acordo com suas apresentações localizadas, generalizada e mista foi relevante do ponto de vista clínico, laboratorial e evolutivo / Introduction: poikilodermatous mycosis fungoides (pMF) is a clinical variant of mycosis fungoides (MF). It is more indolent than classic MF and is characterized by the presence of poikiloderma. The matrix metalloproteinases (MMPs) and their specific inhibitors TIMP (Tissue Inhibitors of Metalloproteinases) are involved in oncogenesis. Specifically, MMP2 and MMP9 and their inhibitors, TIMP-2 and TIMP-1, respectively, have been related to prognosis in tumors. There are few studies on MMP and none on the role of TIMPs in MF. Objectives: To evaluate if there is a relationship between the presence and activity of MMP2 and MMP9 and their inhibitors TIMP2 and TIMP1, and the aggressiveness of MF. To describe a casuistic of poikilodermatous mycosis fungoides in an outpatient clinic in the Dermatological Division of Hospital das Clinicas of University of Sao Paulo Medical School. Methods: Retrospective analysis of 54 cases of pMF, this included 25 localized pMF (LpMF), 14 generalized pMF (GpMF) and 15 mixed pMF. For the analysis of MMPs and TIMPs, the pMF groups were compared with 7 normal skin samples (NS), 10 cases of initial classical MF (cMF), 9 cases of non-transformed tumor MF (nt MFT) and 10 transformed tumor MF (t MFT). Results: The proportion of women : men was 2.44. The pMFs groups showed a longer period of time from the first symptoms to the diagnosis than the cMF group. The GpMF group had a higher incidence of pityriasis lichenoides chronica-like lesions (PLC) (79%) than the other groups. There was a high incidence of hypopigmented MF (62%) in the mixed pMF group. Histology showed typical characteristics of MF and, additionally, atrophy, telangiectasia and pigmentary alterations compatible with pMF. At immunohistochemistry the cases were predominantly CD3+, CD4+, CD7-, CD8- phenotype in all groups, and the pMF groups had a significantly lower prevalence of CD8+ phenotype than the cMF group. The GPMF group showed low positivity for clonality of the T-cell receptor at the T skin (12.5%) compared to the other groups. The MMP2 was more present in the epidermis for the cMF and pMF groups compared to MFT. In the superficial dermis, the cMF, LpMF and GpMF groups showed more MMP2 than normal skin, however there was no statistical difference between the three groups. There was no statistical difference in the presence of MMP2 in the deep dermis between the groups. The zymography showed higher MMP2 activity in the MFT group. There was no TIMP-2 expression by the normal epidermis. The epidermis of cMF and pMFs groups marked TIMP-2 in a similar way, but at a lower intensity than the MFT groups. In the superficial dermis, there was no statistical difference between the cMF and pMFs groups. TIMP-2 was more expressed in the deep dermis of the two MFT groups compared to all of the other groups. In the epidermis and superficial dermis, the MMP9 was more expressed in cMF compared to pMF groups. In the deep dermis, MMP9 expression was higher in the MFT groups, followed by cMF and finally pMF. The MMP9 activity was higher in the nt MFT group compared to other groups. TIMP-1, in epidermis, superficial dermis and deep dermis was more expressed in the cMF group compared to other groups. Discussion: The study confirmed that the pMF is an indolent form of MF and the time period between the symptoms and the diagnosis in pMF was longer than in classical MF. There were clinical differences amongst the groups of pMF. The GpMF group had a higher prevalence of PLC-like lesions than the mixed form of pMF, which had more hypochromic lesions. Histology of pMF was similar to descriptions provided in other case studies. However, the low CD8 positivity differs from previous reports. The MMP2 appeared to be a marker of activity for MF in our work, especially when their presence by immunohistochemistry was associated with the enzyme activity. The expression of MMP9 in our samples was consistent with previous data from other case studies, being more expressed in the most aggressive forms of MF and histologically more localized in most active sites of the tumor. TIMP-1 was expressed in an analogous manner to MMP9, as previously described in the literature. TIMP-2, in turn, followed the distribution pattern of MMP2. However, it was not expressed by normal skin and was more expressed by the MFT group, which did not occur with the MMP2 in immunohistochemistry. Conclusions: The expression of MMP and TIMP was correlated with the location of higher lymphocyte activity and with the aggressiveness of MF. The activity of MMP2 and MMP9 was higher in the MFT groups than the more indolent groups. It was important to split the pMF cases according to their presentation (GpMF, LpMF and mix pMF) from a clinical, laboratory and prognostic point of view

La variante lymphocytaire du syndrome hyperéosinophilique (L-SHE) est une pathologie extrêmement rare caractérisée par une prolifération monoclonale de lymphocytes T surproduisant l’interleukine IL-5, responsable d’une hyperéosinophilie persistante. En outre, un immunophénotype aberrant CD3−CD4+ est fréquemment observé à la surface des cellules T clonales. Cette pathologie se distingue par une lymphoprolifération chronique indolente habituellement révélée par une hyperéosinophilie sanguine et une infiltration éosinophilique des tissus cutanés. Toutefois, l’évolution vers un lymphome T observée chez certains patients suggère la présence d’un potentiel malin des cellules T. Ce modèle représente donc une rare opportunité d’identifier les changements moléculaires liés aux différentes étapes du processus transformant lymphoïde T.<p>Dans le cadre de ce travail, nous avons cherché à établir les caractéristiques cytogénétiques et moléculaires des cellules T CD3−CD4+ d’une cohorte de patients L-SHE. L’analyse cytogénétique de cellules T CD3−CD4+ isolées au moment du diagnostic chez deux patientes (P1 et P2) a révélé la présence d’une délétion similaire 6q13-q22.1. En étudiant les stades cliniques successifs de P1 et P2, nous avons montré la persistance des cellules porteuses de la délétion 6q au cours de la progression chronique et leur prédominance lors du développement d’un lymphome T chez P1. Ces résultats suggèrent l’implication précoce et potentiellement critique de la délétion 6q dans cette pathologie lymphoproliférative T. L’analyse des dérégulations transcriptionnelles résultant de ce remaniement a montré une réduction de l’expression des gènes pro-apototiques BACH2 et PA26 dans les cellules T CD3−CD4+ de P1 et P2. En particulier, BACH2, dont l’expression diminue continuellement au cours de l’évolution de P1, jouerait un rôle oncosuppresseur dans la lymphogenèse T.<p>Afin d’identifier les modifications moléculaires des cellules T clonales, nous avons analysé l’expression de 95% des gènes humains dans les cellules T CD3−CD4+ de trois patients en phase chronique (P1, P2 et P3). La grande homologie des changements transcriptionnels chez les trois patients indique une altération des mêmes mécanismes moléculaires. Ainsi, un profil immunophénotypique exhaustif, validé chez trois patients supplémentaires, a pu être établi. En outre, les dérégulations des voies apoptotiques, TGFβ ou<p>9<p>encore de signalisation intracellulaire altèrent l’homéostasie des cellules T CD3−CD4+ pouvant favoriser la perte de la capacité apoptotique et/ou la croissance cellulaire. Cette signature moléculaire a été étendue par l’identification de 20 microARNs dont l’expression est dérégulée dans les cellules T CD3−CD4+ d’une cohorte de 6 patients. Par ailleurs, la modification de l’expression des récepteurs impliqués dans la migration leucocytaire au cours de l’évolution de P1 pourrait expliquer l’infiltration ganglionnaire des cellules T clonales et la progression du lymphome.<p>La caractérisation des désordres cytogénétiques et moléculaires des cellules T CD3−CD4+ chez les patients L-SHE permettrait à terme d’identifier de nouveaux marqueurs diagnostiques et contribuer ainsi au développement de nouvelles cibles thérapeutiques dans une grande diversité de pathologies lymphoprolifératives de type Th2. / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished

Le lymphome angioimmunoblastique à cellules T (AITL) est un lymphome périphérique à cellules T agressif dont les symptômes sont la lymphadénopathie et l'hypergammaglobulinémie. Actuellement, les patients atteints du AITL ont des options de thérapeutiques limitées et des résultats cliniques défavorables, avec un taux de survie sur 5 ans d'environ 30%. Les cellules tumorales du AITL proviennent de cellules T CD4+ appelées cellules T auxiliaires folliculaires (Tfh). Les cellules Tfh sont essentielles dans le centre germinatif (GC), où elles facilitent l'expansion et la différentiation des cellules B en plasmocytes. Cette fonction d'aide est soutenue par de nombreuses protéines dérivées des cellules Tfh et des programmes de transcription qui pourraient aussi fonctionner dans les cellules tumorales du AITL. Par conséquent, la perturbation des principaux mécanismes de signalisation soutenant l'identité des cellules Tfh et leurs interactions avec les cellules B pourrait inhiber la croissance du AITL. Des études ont démontré que les cellules hyperactives de type Tfh provoquent une accumulation de cellules immunitaires telles que les cellules B, les plasmocytes et les macrophages dans les tumeurs. Cependant, le microenvironnement du AITL n'a pas été bien étudié et il n'a pas été vérifié si certaines cellules immunitaires pourraient être utilisées pour arrêter la croissance de la tumeur. Bien que l’on trouve des cellules Tfh circulantes dans l’AITL humain, le taux de propagation peut varier d’un patient à l’autre. Ainsi, une possibilité est la présence de mécanismes de surveillance immunitaire s'opposant à la progression de la tumeur. En accord avec cette hypothèse, un signal positif pour la phagocytose nommé SLAMF7 (contrebalancé par la voie inhibitrice CD47-SIRPα) est exprimé dans un sous-ensemble de patients atteints du AITL. Toutefois, la corrélation entre les différents niveaux d'expression du SLAMF7 et l'amélioration des résultats pour les patients n'a pas été étudiée. En utilisant des souris Roquinsan/+, qui développent spontanément l’AITL, nous avons étudié le rôle des mécanismes de signalisation immunitaire dans les cellules tumorales de type Tfh et du microenvironnement tumoral. Nous avons cherché à inhiber les protéines et les voies de signalisation typiques des cellules Tfh dans les tumeurs afin d'évaluer la valeur thérapeutique potentielle. Nous avons aussi étudié le rôle de la phagocytose dépendante des macrophages dans le contexte SLAMF7 et comment la modulation de la signalisation de CD47-SIRPα peut améliorer l'efficacité de la phagocytose des cellules tumorales. Notre hypothèse centrale est qu'en supprimant les programmes fondamentaux des cellules Tfh ou en favorisant l'élimination phagocytaire des cellules tumorales de type Tfh, nous pouvons favoriser la régression de la tumeur. Nous avons démontré que les tumeurs AITL nécessitent des protéines d’identité des cellules Tfh essentielles telles que le facteur de transcription Bcl6 et la protéine adaptatrice SAP, ainsi que la communication entre les cellules T et B (T-B). Même en l'absence de GC classiques, les cellules tumorales de type Tfh ont apporté un soutien aux cellules B. Cela est démontré par des titres élevés d'IgG et l'accumulation de cellules précurseurs des plasmocytes dans les tumeurs. Nous avons trouvé des preuves de l'opposition entre la surveillance immunitaire et l'évasion au sein des tumeurs de type AITL, car les cellules Tfh augmentent l’expression de la molécule inhibitrice CD47 tandis que les macrophages stimulent le niveau de SLAMF7. Les cellules de type AITL ont été phagocytées plus efficacement in vitro quand la signalisation du CD47 était bloquée. En résumé, nous démontrons que les voies de signalisation importantes pour l'identité des cellules Tfh et la communication entre les cellules T et B sont essentielles pour la progression de l’AITL et suggèrent qu’une surveillance immunitaire continue par les macrophages peut influencer l’évolution de la maladie. Des études futures pourraient explorer la possibilité de combiner des inhibiteurs de l'activité des cellules Tfh ou T-B avec des médicaments qui stimulent l'activité phagocytaire antitumorale pour améliorer l'efficacité thérapeutique du traitement. / Angioimmunoblastic T cell lymphoma (AITL) is an aggressive peripheral T cell lymphoma manifesting with symptoms such as generalized lymphadenopathy and hypergammaglobulinemia. Currently, AITL patients have limited treatment options and poor clinical outcomes with a 5-year survival rate around 30%. AITL tumor cells derive from a subset of CD4+ T cell, the T follicular helper (Tfh) cell. Tfh cells are essential in germinal centers (GC), where they facilitate B cell expansion and differentiation into plasma cells. This helper function is supported by numerous Tfh cell-derived proteins and transcriptional programs which may still be operational in AITL tumor cells. Therefore, disrupting key signaling mechanisms sustaining Tfh cell identity and their ability to interact with B cells could inhibit AITL tumor growth. Studies have demonstrated that these hyperactive Tfh-like cells lead to the accumulation of immune cell subsets such as B cells, plasma cells, and macrophages within tumor lymph nodes. Nevertheless, the AITL tumor microenvironment itself has not been well-studied and whether some immune cells could be harnessed to impede tumor growth has not been tested. In human AITL, although circulating Tfh cells have been reported, the rate of tumor spreading can vary between patients. As such, one possibility is the presence of immune surveillance mechanisms opposing tumor progression. In line with this idea, SLAMF7, a positive signal for macrophage-mediated phagocytosis (counterbalanced by the inhibitory CD47-SIRPα pathway), is expressed in a subset of AITL patients. Despite this, whether differing levels of SLAMF7 expression correlates with improved patient outcomes has not been investigated. Using Roquinsan/+ mice, a spontaneous AITL-like mouse model, we addressed the role of immune signaling mechanisms within Tfh-like tumor cells and the surrounding tumor microenvironment that would promote tumor regression. First, we aimed to inhibit signature Tfh cell proteins and downstream signaling pathways in developed AITL-like tumors to evaluate potential therapeutic value. Second, we investigated the role of macrophage-mediated phagocytosis in the context of SLAMF7 and how modulating CD47-SIRPα signaling may enhance the efficiency of AITL tumor cell engulfment. Our central hypothesis is that by removing fundamental Tfh cell supporting programs from tumor cells or by promoting the phagocytic removal of Tfh-like tumor cells we can favour tumor regression and impair future growth. Through this work, we demonstrated that AITL-like tumors continuously require critical Tfh cell identity proteins such as transcription factor Bcl6 and adaptor protein SAP, as well as T cell-B cell (T-B) crosstalk. Importantly, despite the absence of conventional GCs, Tfh-like tumor cells provided functional support to B cells as evidenced by elevated IgG titers and accumulation of plasma cell precursors in tumors. We also found evidence of opposition between immune surveillance and evasion within AITL-like tumors as Tfh-like cells upregulated inhibitory CD47 levels while macrophages increased expression of prophagocytic SLAMF7. Moreover, AITL-like tumor cells were more efficiently phagocytosed in vitro when CD47 signaling was blocked. Taken together, we demonstrate that pathways important for Tfh cell identity and T-B communication are critical for AITL-like disease progression and suggest that ongoing macrophage-mediated immune surveillance may influence disease outcomes. Future studies may explore combining inhibitors of Tfh cell activity or T-B crosstalk along with drugs which boost antitumor phagocytic activity to further improve the therapeutic efficacy of treatment.

Ziel dieser Arbeit war die Identifizierung von Tumor-assozierten T-Zellepitopen (TATE) in kutanen T-Zelllymphomen (CTCL) und die Charakterisierung der Tumour-spezifischen zytotoxischen Immunabwehr. Zwei Tumor-spezifische T-Zellklone wurden aus den Tumor-infiltrierenden Lymphozyten (TIL) eines CTCL-Patienten etabliert. Die potentiellen natürlichen T-Zellepitope und Mimotope (synthetische Epitope ohne natürliche Korrelate aber mit meist hohen T-Zellaktivitäten) für diese Klone wurden mit einer kombinatorischen Peptidbibliothek identifiziert. Die Qualität und Quantität der T-Zellaktivitäten waren bei den jeweiligen Peptiden unterschiedlich. Die funktionellen Aviditäten varierten dabei um 3 Größenordnungen. Bei den einzelnen Peptiden korrelierte die Zytolyse und Zytokinsekretion nicht immer. Mit einigen Mimotopen wurden CTCL-Patienten für therapeutische Zwecke vakziniert. Die Frequenzen der Mimotop-spezifischen T-Zellen erhöhten sich während der ersten Vakzinationszyklen und tumorizide Aktivitäten konnten nachgewiesen werden. Diese ersten klinischen Anwendungen der Mimotope zeigen die Möglichkeit solcher Mimotope die sonst unzureichende Immunabwehr zu modulieren. Die Identifizierung neuer TATE ermöglichte die weitere Untersuchung der Tumor-spezifischen T-Zellen in der Peripherie und im Tumor des Patienten. Diese Analysen zeigten, dass diese Zellen im peripheren Blut aktiv aber im Tumor inaktiv waren. Die TILs waren vom effektor-memory Phänotyp expremierten aber nur schwach oder z. T. keine der Moleküle mit Effektorfunktion. Das immunsuppressive Zytokin TGF-beta könnte eine wichtige Rolle bei dieser unzureichenden Immunabwehr bei CTCL spielen. / The major goals of this work was the identification of tumour-associated T cell epitopes (TATE) in cutaneous T cell lymphoma (CTCL) and the characterisation of the tumour-specific cytolytic immune response. Two tumour-specific cytolytic T cell clones were established from the tumour-infiltrating lymphocytes (TIL) of one CTCL-patient. The potential natural T cell epitopes and mimotopes (epitopes without natural correlates but with more T cell stimulating capacity) for these T cell clones were identified using a combinatorial peptide library. The quantity and quality of the T cell response was different. The functional avidity of the peptides differed more than 3 orders of magnitude. The cytolysis and cytokine release did not correlate for each peptide. Some of the mimotopes were injected into CTCL-patients for therapeutic purpose. The frequency of the mimotope-specific T cell increased during the first vaccination cycles and a tumouricidal capacity could be observed. This first clinical application of the mimotopes showed the capacity of the mimotopes for the modulation of weak anti-tumour immune response. The identification of the new TATE allowed further characterisation of the tumour-specific T cells in the periphery and in the tumour of the patient. High frequency of the tumour-specific T cells could be detected in the tumour but they failed to show effector functions in comparison to the tumour-specific T cells in the peripheral blood. The tumour-specific T cells had the effector memory phenotype but expressed none or less amount of the cytolytic effector molecules. The reason for the suboptimal anti-tumour response in CTCL could be the immunesuppressive cytokine TGF-beta.