Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In the present study, the sera levels of soluble CD40 ligand (sCD40L) and matrix metalloproteinase-9 (MMP-9) were quantified by Luminex assay in Visceral leishmaniasis patients before and during treatment follow-up and after regular antimony treatment and also in individuals exposed to infection, living in endemic areas. Different from the other molecules present in sera from classic VL patients, sCD40L and MMP-9 are fairly increased, and increase over time during the follow-up of VL patients undergoing antimony treatment. sCD40L and MMP-9 sera levels were also high in individuals living in endemic settings at high risk of infection (endemic controls). On the other hand, sCD40L and MMP-9 were not observed in sera from non-endemic controls, which are not exposed of infection. Additionally, negative correlations were found between spleen sizes and MMP-9 before treatment and sCD40L at day 15 of treatment. Negative correlations were also found between parasite load with both sCD40L and MMP-9. These findings indicate that both molecules can be used in monitoring therapeutic efficacy in VL. Furthermore, these data suggest a protective effect of these molecules, since the individuals exposed to infection without the symptoms of disease have high sera levels of sCD40L and MMP-9. These data were published in BMC Infectious diseases journal [1]. To confirm the protective effect of sCD40L present in sera of VL patients and determine if this molecule had biological activity, the ability of sera from patients containing high levels of this molecule sCD40L to control infection in vitro in Leishmania infantum infected macrophages, and the ability to induce cytokines production. Thereby, macrophages from of healthy donor were infected with Leishmnia infantum, and later incubated in presence of sera from individuals exposed to infection in presence of anti-CD40L. The infection was evaluated by counting of the number of infected macrophages/100 and the number of intracellular amastigotes/100 macrophages. The data showed that serum sCD40L decrease the number of infected macrophages and the number of intracellular amastigotes. The blockage of sCD40L activity with specific antibody, increase the infection. Moreover, the analysis of cytokines in supernatant of these macrophage cultures by Luminex assay demonstrated that sCD40L induces the IL-12, IL-23, IL-27, IL-15 e IL-1 production. The levels of these cytokines is inversely correlated with infection rate and the number of intracellular parasites from infected macrophages. A second manuscript with these data were published in PLOS One [2] . These results demonstrated that serum sCD40L from individuals exposed to VL improve the microbicide effect and the inflammatory cytokine production, suggesting its potential use in VL immunotherapy. Nevertheless, there is still a long way to be approached in future experimental and clinical studies. / No presente estudo, os níveis séricos dos marcadores inflamatórios CD40 ligante solúvel (sCD40L) e da metaloproteinase de matrix-9 (MMP-9) foram quantificados por Luminex nos pacientes com leishmaniose visceral antes, durante e após o tratamento com antimonial, e em indivíduos controles expostos à infecção, residindo em áreas endêmicas. Ao contrário das outras moléculas inflamatórias presentes nos soros de pacientes com LV, as moléculas sCD40L e MMP-9 apresentaram elevação moderada, havendo um aumento significativo de ambas no decorrer do tratamento com antimonial. Níveis séricos elevados de sCD40L e MMP-9 também foram encontrados nos indivíduos controles sem doença, provenientes de áreas endêmicas e expostos a infecção. Entretanto, o sCD40L e a MMP-9 não foram detectados nos soros de indivíduos de áreas não endêmicas, os quais não estão expostos a infecção. Adicionalmente, correlações negativas entre o tamanho do baço com a MMP-9 antes do tratamento e com o sCD40L 15 dias após o início do tratamento foram observadas, bem como correlações negativas entre ambas as moléculas com a carga parasitaria dos pacientes. Estes resultados indicam que estas moléculas podem ser utilizadas no monitoramento da eficácia terapêutica na leishmaniose visceral. Além disso, estes dados nos sugerem um efeito protetor dessas moléculas contra a doença, desde que os indivíduos expostos e sem a doença apresentaram concentrações elevadas dessas moléculas. Estes dados foram publicados no BMC Infectious diseases [1]. Para confirmar o efeito protetor do sCD40L e investigar se a molécula presente nos soros dos pacientes com LV tinha atividade biológica, foi avaliado se o sCD40L presente no soro dos indivíduos infectados teria ação na resposta leishmanicida e na produção de citocinas por macrófagos infectados por Leishmania infantum. Dessa forma, macrófagos de doadores normais foram infectados com L. infantum e posteriormente incubados com soro de indivíduos expostos a infecção na presença de anti-CD40L. A avaliação da infecção através da contagem de células infectadas e do número de parasitas intracelulares demonstrou que a presença do sCD40L sérico diminui o número de macrófagos infectados e o número de amastigotas intracelulares. O bloqueio da atividade do sCD40L com anticorpo específico reverteu este efeito, aumentando a infecção. Além disso, a análise de citocinas no sobrenadante das culturas de macrófagos por Luminex mostrou que a adição de sCD40L induziu a produção de IL-12, IL- 23, IL-27, IL-15 e IL-1. As concentrações destas citocinas correlacionaram-se inversamente com as taxas de infecção e com o número de parasitas intracelulares nos macrófagos infectados. Um segundo artigo com estes resultados foi publicado na PLOS One [2]. Estes resultados demonstram que o sCD40L sérico dos indivíduos expostos à LV melhora a capacidade microbicida e a produção de citocinas inflamatórias, sugerindo seu potencial uso na imunoterapia na LV humana, embora este seja um longo caminho a ser abordado em estudos futuros experimentais e clínicos.

Visceral leishmaniasis constitutes a serious public health problem in the world, demanding effective measures for its control and treatment. The current treatments are far from ideal for the need for prolonged treatment, development of drug resistance and significant side effects. Thus the search for new therapeutic options in addition to evaluating the effectiveness of adjuvant therapy is very important. The aim of this study was to evaluate biomarkers sCD40L and clinical outcome in the adjuvant treatment of human visceral leishmaniasis with N-acetylcysteine. From an intervention study, kind clinical trial, blinded, randomized, were investigated 60 patients from the University Hospital with a positive diagnosis for acute visceral leishmaniasis. These patients were divided into two groups of 30: Study Group - which made use of antimony penta valent standard dose supplemented with N-acetyl-L-cysteine and the control group - which only used the standard dose antimony. The serum levels of soluble ligand sCD40L were significantly higher elevation and steeper over time in SbV + NAC group compared to the Sb group. Furthermore, the distribution of values sCD40L significantly increased in both groups after 15 days of treatment, thereafter no significant change over time. Likewise the size of the spleen, and serum cytokine levels (TNF-α, IL-10, IL-12p40) decreased during treatment in both groups while the number of neutrophils, eosinophils and platelets increased. Several published studies indicate the importance of CD40 / sCD40L interaction for an effective immune response and that this interaction occurs via reciprocal signaling through protein kinase-induced phosphorylation of MAPK p38 and ERK1 / 2 mitogen. Other studies show as a strategy of evading the immune response and the establishment of infection, Leishmania inhibits p38 MAPK signaling triggered by CD40. And the glutathione redox system regulates the production of IL-12 induced by LPS through the activation of p38 MPAK, and furthermore, the effect initiation of IFN-γ and IL-12 is in part a consequence of the equilibrium glutathione redox. NAC was able to increase serum sCD40L concentrations throughout treatment. Treatment with NAC improved the patients´ clinical parameters associated with the prognosis of the patients: reduced spleen size increased number of neutrophils / lymphocytes and eosinophils faster. The results suggest that the addition of NAC to conventional therapy improves the immune response of patients, particularly in the reduction of serum IL-10, IL-12p40 and increase in sDC40L that this response occurs as early as two weeks. It is likely that increased levels of sCD40L the NAC occurs through the activation of p38 MAPK pathway glutathione redox system. / A leishmaniose visceral constitui-se um grave problema de saúde pública no mundo, demandando medidas eficazes no seu controle e tratamento. A terapêutica atual está longe de ser a ideal pela necessidade de tratamentos prolongados, desenvolvimento de resistência aos medicamentos e efeitos colaterais significativos. Desse modo a busca de novas opções terapêuticas além de avaliação da eficácia de terapêutica adjuvante é muito importante. O objetivo deste trabalho foi avaliar biomarcadores de evolução clínica e CD40 ligante solúvel (sCD40L) no tratamento adjuvante da leishmaniose visceral humana com N-acetilcisteína. A partir de um estudo de intervenção, tipo ensaio clínico, cego, aleatorizado, foram investigados 60 pacientes do Hospital Universitário com diagnóstico positivo para leishmaniose visceral aguda. Esses pacientes foram distribuídos em dois grupos de 30: Grupo Estudo que fez uso do antimônio penta valente dose padrão complementado com o N-acetil-L-cisteína e o Grupo Controle - que fez uso apenas do antimônio dose padrão. Os níveis séricos do sCD40L foram significativamente maiores e com elevação ao longo do tempo mais acentuada no grupo SbV + NAC em relação ao grupo SbV. Além disso, a distribuição dos valores de sCD40L aumentaram significativamente em ambos os grupos a partir de 15 dias de tratamento, a partir de então sem variação significativa ao longo do tempo. Do mesmo modo a dimensão de baço e níveis séricos de citocinas (TNF-α, IL-10, IL-12p40) diminuíram ao longo do tratamento nos dois grupos enquanto o número de neutrófilos, eosinófilos e plaquetas aumentaram.Vários estudos da literatura assinalam a importância da interação CD40/sCD40L para uma efetiva resposta imune e que essa interação ocorre por meio de sinalização recíproca através de fosforilação da proteína quinase mitógeno induzida de MAPK p38 e ERK1/2. Outros estudos mostram como uma estratégia de evasão da resposta imune e o estabelecimento de infecção, a Leishmania inibe a sinalização p38MAPK acionada pelo CD40. E que o sistema redox de glutationa regula produção de IL-12 induzida pela LPS através da ativação da p38 MPAK e, além disso, o efeito de iniciação de IFN-γ e a produção de IL-12 é em parte uma conseqüência do equilíbrio redox da glutationa. O NAC foi capaz de aumentar as concentrações séricas de sCD40L ao longo do tratamento. O tratamento com NAC melhorou os parâmetros clínicos dos pacientes associados com o prognóstico dos pacientes: reduziu tamanho do baço, aumento do número de neutrófilos/linfócitos e eosinófilos mais rapidamente. Os resultados sugerem que a adição do NAC ao tratamento convencional melhora a resposta imunológica dos pacientes, sobretudo na diminuição dos níveis séricos de IL-10, IL-12p40 e na elevação da sDC40L que essa resposta ocorre já a partir de duas semanas. É provável que o aumento dos níveis de sCD40L pelo NAC ocorra através da ativação do MAPK p38 via o sistema redox de glutationa.

TRAIL (TNF-Related Apoptosis Inducing Ligand) et CD40 Ligand, membre de la superfamille (SF) du TNF (Tumor Necrosis Factor) apparaissent comme des cibles attractives pour la thérapie ciblée du cancer. Une caractéristique commune des membres de la SF-TNF est la structure homotrimérique du ligand qui oligomérise les récepteurs pour induire la signalisation cellulaire. Cette interaction multivalente entre ligands et récepteurs est déterminante dans l’induction de la réponse cellulaire. L’objectif de cette thèse est de i) développer des ligands multivalents de TRAIL-R2 et CD40 afin d’améliorer leur efficacité anti-tumorale puis de les associer dans des stratégies anti-tumorales innovantes et ii) de caractériser les interactions entre ces ligands et les récepteurs à la surface de la cellule pour comprendre l’impact de l’oligomerisation sur l’initiation de l’apoptose au niveau membranaire.Ainsi nous avons utilisé des peptides cycliques spécifiques du récepteur de TRAIL-R2 (TRAILmim/DR5) que nous avons multimérisés sur des plateformes chimiques innovantes. Nous nous sommes également intéressés à l’état d’oligomérisation des récepteurs avant leur contact avec le ligand dans le but de mieux comprendre les interactions multivalentes. Enfin, nous avons caractérisé à l’aide de la technique de résonance plasmonique de surface et d’un biocapteur basé sur la fluorescence les interactions entre ces ligands multivalents et le récepteur TRAIL-R2. Ces travaux nous ont donc montré la nécessité d’analyser les interactions entre ligands et récepteurs directement à la surface de la cellule pour améliorer le développement de ligands pro apoptotiques efficaces. / TRAIL (TNF- Related Apoptosis Inducing Ligand) and CD40Ligand, members of the superfamily (SF) of TNF (Tumor Necrosis Factor), appear as attractive targets for cancer therapy. A common feature of members of the TNF-SF is the homotrimeric structure that oligomerized their receptors to induce cell signaling. This multivalent interaction between ligands and receptors is crucial for apoptosis induction.The aims of this thesis is to i) develop multivalent ligands of TRAIL -R2 and CD40 to enhance their antitumor efficacy and to associate them in innovative strategies and ii) to characterize the interactions between ligands and receptors at cell surface to understand the impact of oligomerization on the initiation of apoptosis at membrane level.We used cyclic peptides specific of TRAIL-R2 (TRAILmim/DR5) that we multimerized on innovative chemical scaffolds. We also interested in the state of receptor oligomerization before their contact with the ligand in order to better understand the multivalent interactions. Finally, we characterized using the technique of surface plasmon resonance and biosensor based fluorescence interactions between multivalent ligands and TRAIL- R2.In this work we showed the need to analyze the interactions between ligands and receptors directly on the surface of the cell to improve the development of effective pro -apoptotic ligands.

No description available.

Die Erkrankungen des atopischen Formenkreises sind durch eine hypererge Immunreaktion auf harmlose Umwelt-Antigene gekennzeichnet und umfassen u.a. die klinischen Bilder der allergischen Rhinokonjunktivitis, des allergischen Asthmas und der atopischen Dermatitis. Die Pathogenese atopischer Krankheiten ist zwar noch nicht hinreichend aufgeklärt, aber man schreibt der Regulation des IgE bei der Entstehung und Erhaltung dieser Krankheiten eine zentrale Rolle zu. Auf der Suche nach potentiellen anti-allergischen Therapeutika wurde in dieser Arbeit erstmalig der Einfluß von 1alpha,25-Dihydroxyvitamin-D3 (VD) und dem niedrigkalzämischen Derivat EB1089 in vitro auf die IgE-Produktion humaner B-Zellen gesunder Spender untersucht, die zuvor mit anti-CD40+IL-4 stimuliert wurden, wodurch der Isotypenklassenwechsel nativer B-Zellen nach IgE resultierte. Das Steroidhormon VD ist für die Kalziumhämostase essentiell, jedoch sind die immunregulatorischen Funktionen des VD noch relativ unerforscht. Die Experimente dieser Arbeit zeigen eine starke, dosisabhängige Hemmung der IgE-Produktion in diesem Modell, die spezifisch von VD und dem Derivat EB1089 vermittelt wird. Auch bei PBMC atopischer Spender konnte die basale IgE-Produktion mit VD dosisabhängig signifikant gehemmt werden. Eine mögliche Proliferationshemmung, die diese Wirkung erklären könnte, konnte ausgeschlossen werden. Die Messung der Produktion der anderen Immunglobulinklassen (Ig) IgA, IgG und IgM bestätigte, daß die Zellviabilität und die Ig-Produktion außer der von IgE durch VD und EB1089 in diesem Modell nur wenig beeinflußt wird. Diese Beobachtungen weisen auf eine selektive, spezifische Inhibition der IgE-Synthese durch das Molekül aus der Familie der Steroidhormone hin. Auf der Suche nach möglichen indirekten Mechanismen der IgE-Regulation, die die VD-vermittelte Inhibition der IgE-Synthese erklären könnten, wurde der Einfluß von VD auf die Expression der kostimulatorischen Faktoren der IgE-Produktion CD23 (Fc(-RII), CD54 (ICAM-1) und CD86 (B7.2) sowie auf die Sekretion der Zytokine, IL-6, sCD23 und IFN-gamma untersucht. Die Ergebnisse dieser Arbeit deuteten jedoch nicht auf eine Beteiligung der genannten Faktoren an der Regulation der VD-vermittelten Hemmung der IgE-Produktion hin. Diese in vitro Arbeit stellt einen wichtigen Hinweis auf eine potentielle Nutzung von VD in der anti-allergischen Therapie dar, jedoch deutet die beobachtete Hemmung der IgE-Synthese von PBMC atopischer Spender darauf hin, daß auch in vivo die IgE-Synthese gehemmt werden kann. Es sind daher weitere Studien des Signalweges des VD auf molekularer Ebene, sowie in vivo Versuche notwendig, um zu klären, ob VD selbst oder ein möglichst nicht-kalzitropes VD-Derivat mit ausgeprägten immunologischen Eigenschaften für die anti-allergische Therapie geeignet ist. / Atopic diseases are characterized by a hyperergic immunoreaction towards harmless environmental antigens, expressed by the clinical phenotype of allergic rhinitis, allergic asthma and atopic dermatitis. Even though the pathogenesis of atopic diseases are not completely clear, the regulation of IgE plays a crucial role in the development and maintenance of these disorders. In search of new potentially anti-allergic drugs, the effect of 1alpha,25-Dihydroxyvitamin-D3 (VD) and the low-calcemic synthetic analogue EB1089 was determined in anti-CD40+Il-4-mediated IgE-production by B-cells of healthy donors in vitro. The essential role of VD in calcium hemostasis is well understood, but the immunoregulatory functions of the hormone are still quite unclear. The present data show for the first time, that VD and the analogue EB1089 mediate a strong, dose-dependent inhibition of IgE-synthesis. In PBMC of atopic donors, the baseline IgE-production was also significantly inhibited by VD. Anti-CD40+IL-4-mediated proliferation of B-cells in the presence of VD was only modestly modulated, as well as the production of the other immunoglobulin-isotypes IgA, IgG and IgM. Taken together these data suggest a specific and selective inhibition of IgE-synthesis by VD and EB1089. In order to explore possible mechanisms of VD induced IgE-inibition, the expression of CD23 (Fc(-RII), CD54 (ICAM-1) and CD86 (B7.2) on anti-CD+IL-4 stimulated B-cells was determined as well as IL-6, sCD23 und IFN-gamma. However, none of these molecules were significantly modulated in the presence of VD. Taken together, these in vitro experiments suggest a potential role of VD as a new anti-allergic drug, which is underlined by the observed inhibition of IgE-production by PBMC in allergic donors.

IgE ist das Schlüsselmolekül Typ-I allergischer Erkrankungen.. Die Produktion von IgE wird durch die Interaktion des Oberflächenmoleküls CD40 auf B-Zellen mit seinem Liganden (CD40L), dass von aktivierten T-Zellen exprimiert wird, sowie über Signale durch die Zytokine IL-4 oder IL-13 von B-Zellen produziert. Die CD40/IL-4-abhängige IgE-Produktion in vitro kann einerseits als Modell zum Verständnis der Entstehung allergischer Erkrankungen eingesetzt werden; andererseits können potenziell therapeutisch wirksame Substanzen untersucht werden. Untersuchungen zum Verständnis allergischer Erkrankungen zeigen, dass LTa nach CD40/IL-4-Stimulation von humanen B-Zellen vermehrt produziert wird und dies in autokriner Weise zu einer Steigerung der CD40/IL-4-vermittelten Proliferation und IgE-Produktion führt. Darüberhinaus wurde eine vermehrte Produktion von LTa bei allergischen Patienten nachgewiesen, so dass eine funktionelle Relevanz von LTa in der Pathogenese allergischer Erkrankungen zu vermuten ist. Die Arbeiten zu den intrazellulären Mechanismen der LTa-Induktion nach CD40/IL-4-Stimulation demonstrieren, dass sowohl der Transkriptionsfaktor NF-kB als auch verschiedene Proteinkinasen hier eine wesentliche Rolle spielen. Untersuchungen mit Hilfe des CD40/IL-4-abhängigen Systems bei humanen B-Zellen, die einen therapeutischen Einsatz zur Behandlung allergischer Erkrankungen haben könnten, zeigen, dass Retinoide aber auch Vitamin D zu einer erheblichen Hemmung der IgE-Produktion in- vitro führen. / IgE plays a key role for the development of type I related allergic diseases. Production of IgE by B cells is induced by the interaction of the surface molecule CD40 with its natural ligand (CD40L), which is expressed on activated T cells and signals which are provided by the cytokines IL-4 or IL-13. This model can be used for studies either to understand the development of allergic diseases or to investigate novel therapeutic approaches. In the context of the understanding the development of allergic diseases the present work shows that LTa is produced by B cells after CD40+IL-4 stimulation and that increased production of LTa results in enhanced CD40+IL-4 mediated B cell proliferation and IgE synthesis. Furthermore an increased production of LTa was shown in allergic patients indicating the potential role of LTa in allergic diseases. Analysis of the gene regulation of LTa after CD40 stimulation revealed an important role of the transcription factor NF-kB and showed the role of different protein kinases at the intracellular level. Studies using the CD40+IL-4 system in vitro which may have a therapeutical impact revealed that vitamin A and vitamin D are potent inhibitors of IgE production in vitro. Taken together the present work shows new mechanisms of CD40+IL-4 mediated IgE synthesis and also offers new potential therapeutical approaches of allergic diseases.

A deficiência de CD40 Ligante (CD40L) ou síndrome de Hiper-IgM ligada ao X (X-HIGM) é considerada uma imunodeficiência primária combinada de células T e B. O CD40L é expresso na superfície de linfócitos T ativados e interage com o CD40 expresso na superfície de linfócitos B, macrófagos, células dendríticas, células endoteliais e neutrófilos. A interação CD40L-CD40 transmite sinais que induzem ativação, diferenciação e proliferação celular. Nosso objetivo foi analisar as alterações genético-moleculares da molécula CD40L que acometeram indivíduos de 5 famílias brasileiras, ocasionando X-HIGM. Genotipamos 25 indivíduos, sendo 6 pacientes com X-HIGM, 13 parentes relacionados heterozigotos e 6 homozigotos sadios. Dentre os pacientes com X-HIGM dois eram de origem caucasóide e 4 eram mestiços. A idade dos pacientes variou de 2 a 20 anos e o quadro clínico de infecções de repetição teve início em média nos primeiros 4 meses de vida. As principais infecções recorrentes manifestadas pelos pacientes foram pneumonia e otite. O paciente TB apresentou blastomicose, observação original nesta imunodeficiência. A análise genético-molecular foi heterogênea. No paciente TB foi detectado um defeito de splicing levando a deleção do exon 3 (r.345_402del do gene CD40L (CD40LG) no paciente FS uma nova substituição missense g.11856 G>C (c.476 G>C, pW140C), no paciente KC uma substituição nonsense g.11855 G>A (c.475G>A, p. W140X), e nos pacientes CH, FE e VIC uma deleção g. 3074_3077delTAGA, levando a alteração no processamento do RNA. A fenotipagem dos leucócitos demonstrou que a contagem de linfócitos T auxiliares (CD3+CD4+), linfócitos citotóxicos (CD3+CD8+), linfócitos B (CD19+CD40+) e linfócitos T ativados (CD3+CD69+) dos pacientes foram similares aos controles sadios. Contudo, foi observada uma redução significativa nos níveis de expressão de CD40L na superfície de linfócitos CD3+ e CD4+ dos pacientes. A análise dos linfócitos T por microscopia confocal revelou que as células dos homozigotos com expressão residual do CD40L em sua superfície também apresentam redução na densidade da expressão da molécula CD3, sugerindo a necessidade da integridade molecular do CD40L para a expressão normal do CD3. Concluímos que mutações no CD40L que levam à síndrome de X-HIGM são heterogêneas e a análise genético-molecular permitiu um diagnóstico preciso tornando possível o aconselhamento genético e a triagem dos recém-nascidos das famílias avaliadas. / CD40-Ligand (CD40L) deficiency or X linked Hyper-IgM syndrome (X-HIGM) is considered a T and B cell combined primary immunodeficiency. CD40L is expressed on the cell surface of activated T lymphocytes and interacts with CD40, expressed on the surface of B lymphocytes, macrophages, dendritic cells, endothelial cells, and neutrophils. The CD40L-CD40 interaction induces activation, differentiation, and cell proliferation. Our aim was to analyze the molecular-genetic alterations of CD40L molecule affecting individuals of 5 brazilian families, leading to X-HIGM. We genotyped 25 individuals, whom 6 were X-HIGM patients, 13 were heterozygote related patients, and 6 were healthy homozygotes. Within the patients with X-HIGM, two of them were of caucasoid origin and four were mestiços. The patients age ranged from 2 to 20 years and their recurrent infections started in average during their first 4 months of life. The main recurrent infections were pneumonia and otitis. The patient TB presented blastomycosis, a unique observation in this immunodeficiency. The molecular-genetic analysis revealed heterogeneity. TB patient presented a splicing defect causing a deletion of exon 3 (r.345_402del) of CD40L gene (CD40LG). Patient FS presented a new missense mutation g.11856 G>C (c.476 G>C, pW140C). Patient KC presented a nonsense substitution g.11855 G>A (c.475G>A, p. W140X). Patients CH, VIC, and FE presented a deletion g. 3074_3077delTAGA, causing an alteration on RNA processing. The leukocytes fenotyping demonstrated that T helper lymphocytes (CD3+CD4+), T cytotoxic lymphocytes (CD3+CD8+), B lymphocytes (CD19+CD40+), and T activated (CD3+CD69+) cell counts of patients were similar to healthy controls. However it was observed a significant reduction of CD40L expression on cell surface patients CD3+ and CD4+ lymphocytes. The T lymphocyte confocal microscopy analysis revealed that homozygotes with residual expression of CD40L in their surface also presented a reduction on the density of CD3 molecule expression, suggesting the need of molecular integrity of CD40L for normal CD3 expression. We conclude that mutations on CD40L leading to X-HIGM syndrome are heterogeneous and the molecular-genetic analysis allowed a precise diagnosis making possible the genetic counseling and newborn screening of the involved families.

No description available.

No description available.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed June 6, 2008). Includes bibliographical references.