O citomegalovírus (CMV), está entre os principais agentes infecciosos que acometem pacientes transplantados renais. A infecção por CMV está relacionada ao status sorológico do doador e receptor, bem como o tipo e intensidade da imunossupressão utilizada. A infecção, e em especial a doença citomegálica, determinam aumento da morbi-mortalidade após o transplante. O espectro da doença varia desde formas assintomáticas até a doença sistêmica grave com comprometimento de vários órgãos. A doença por CMV é diagnosticada através da evidência laboratorial de infeção, associada a quadro clínico compatível. A técnica da antigenemia identifica a presença do antígeno viral p65 em leucócitos do sangue periférico através de reação de imunoperoxidase utilizando-se anticorpos monoclonais. O objetivo principal deste trabalho foi o de determinar a incidência de infecção por CMV em uma coorte de pacientes transplantados renais usando a antigenemia como ferramenta diagnóstica. Secundariamente buscou-se avaliar o impacto desta infecção nas sobrevidas dos pacientes e dos enxertos em 6 anos de acompanhamento. No período de inclusão no estudo, janeiro de 1994 a fevereiro de 1995, foram realizados 74 transplantes renais na Santa Casa de Porto Alegre–RS. As amostras de sangue para a detecção da antigenemia foram obtidas semanalmente durante a internação hospitalar e posteriormente, sempre que houvesse suspeita clínica de infecção por citomegalovírus. Das 229 amostras analisadas, 51 (22,3%) foram positivas, em 24 pacientes, dos quais 41,6% (10/24) evoluíram de forma assintomática, 33,3% (8/24) apresentaram sintomas leves, e 25% (6/24) desenvolveram sintomas compatíveis com doença citomegálica. Desta forma, coorte estudada, a incidência de infecção e doença por CMV foram de 33,3% e 8,4%, respectivamente. Não houve associação entre as doses de imunossupressores, o uso de anticorpos monoclonais e número de episódios de rejeição com o desenvolvimento de infecção e doença por CMV. Nos transplantes realizados com doadores vivos, a incidência de infecção por CMV nos receptores de rins de doadores com sorologia positiva foi 61,9%, e nos receptores de doadores com sorologia negativa foi 14,3% (p=0,005). Os transplantes com receptores com sorologia negativa transplantados com rins de doadores soropositivos apresentaram incidência significativamente maior de infecção (75%) e doença (75%) por CMV do que os receptores com sorologia positiva transplantados com órgãos de doadores com soronegativos, 13,3% e 0%, respectivamente (p<0,05). A sensibilidade da antigenemia em detectar os pacientes que desenvolveram doença citomegálica foi de 100% e a especificidade foi 72,7%, com valor preditivo positivo de 25% e valor preditivo negativo de 100%. No grupo de pacientes que apresentou doença por CMV, ao término do seguimento, ocorreu um número significativamente mais elevado de perdas do enxerto (85%) do que no grupo de pacientes em que a infecção foi assintomática (29%), acarretando impacto negativo nas curvas de sobrevida de enxertos e pacientes (LogRank; p<0,05). A antigenemia mostrou ser uma ferramenta diagnóstica importante no manejo dos pacientes transplantados renais, possibilitando o diagnóstico precoce da infecção e auxiliando na identificação dos pacientes infectados que estão sob maior risco de desenvolvimento da doença. / Cytomegalovirus (CMV) is a major infectious agent in renal allograft recipients. CMV infection is related to the serologic status of the donor and the recipient, as well as to the type and dosage of immunossupression that the recipient is submitted to. Infection and specially disease due to CMV have determined a rise in morbidity and mortality after transplantation. The spectrum of the disease ranges from completely assymptomatic all the way up to a severe systemic disease with multiple organ compromise. CMV disease is diagnosed through laboratory evidence of infection associated with a compatible clinical presentation. Antigenemia technique identifies the presence of the p65 viral antigen in peripheral blood leukocytes through a peroxidase reaction, using monoclonal antibodies. The objective of this work was to determine the incidence of infection caused by CMV in a cohort of renal transplanted patients, using the antigenemia as a diagnostic tool. Furthermore, the outcome of graft and patients in a 6 year follow-up period was evaluated. During the period of inclusion in the study (January 1994 to February 1995), 74 renal transplants were performed at Santa Casa de Misericórdia, Porto Alegre, RS. Blood samples for detection of antigenemia were obtained weekly during the patient’s in-hospital period, and whenever there was a clinical suspicion of CMV infection afterwards. Of the 229 analyzed samples, 51 (22.3%) were positive in 24 patients, of which 41.6% (10/24) presented no symptoms, 33.3% (8/24) had mild symptoms, and 25% (6/24) developed symptoms compatible with CMV disease. In this cohort, the incidence of infection and CMV disease was 33.3% and 8.4%, respectively. There was no association between the dosage of immunosuppressive agents, the use of monoclonal antibodies and the number of rejection episodes with the development of infection or disease caused by CMV. In living related transplants, the incidence of CMV infection in receptors of serum positive donors was 61.9%, and in the recipients of serum negative donors it was 14.3% (p=0.005). Serum negative recipients transplanted with organs of serum positive donors presented a significantly greater incidence of infection (75%) and disease (75%) than the serum negative recipients transplanted with organs of serum negative donors, 13,3 % and 0% respectively (p<0.05). The sensibility of antigenemia to detect the patients that developed CMV disease was 100%, and the specificity was 72.7%, with a positive predictive value of 25% and a negative predictive value of 100%. At the end of the follow-up, in the group of patients who presented CMV disease the incidence of graft loss was significantly higher than the one observed in the group of patients who remained assymptomatic (85% versus 29% respectively), having a negative impact in the survival curve for both grafts and patients (LogRank; p<0.05). Antigenemia proved to be an important tool in the assessment of renal transplant patients, permitting the early diagnosis of disease, and the identification of infected patients that are at risk for the development of disease.

Orientadores: Sandra Cecilia Botelho Costa, Lilian Tereza Lavras Costallat / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-13T20:41:17Z (GMT). No. of bitstreams: 1 Norberto_CristianeMudinutidaSilva_M.pdf: 1242945 bytes, checksum: 8ce75d400c67b263809938aa66fce948 (MD5) Previous issue date: 2008 / Resumo: Doenças Infecciosas são uma das maiores causas de complicações que ameaçam à vida dos pacientes com doenças reumáticas. O citomegalovírus, um betaherpesvírus, é o maior causador de morbidade e mortalidade em indivíduos imunossuprimidos, podendo causar febre e danos a órgãos como, pulmão, fígado, trato gastrointestinal, medula óssea e retina. Pacientes com LES fazem uso de imunossupressores e estão sob risco de reativar a infecção latente pelo HCMV. Os pacientes HCMV-IgG positivos que usam imunossupressores devem ser monitorizados usando a N-PCR e/ou HCMV antigenemia para que o tratamento antiviral precoce possa suprimir a reativação viral e conseqüentemente a doença associada. Diante do exposto, foram monitorizados 40 pacientes com diagnóstico de Lúpus Eritematoso Sistêmico (SLE) em relação à infecção ativa pelo citomegalovírus humano (HCMV) utilizando as técnicas de Nested-PCR (N-PCR) e Antigenemia (AGM). Foi também verificado o status sorológico IgM e IgG anti- HCMV por ELISA. Para tanto, foram necessárias 2 amostras de sangue por paciente, obtidas através de punção venosa. Os pacientes encontravam-se em diferentes estágios da doença lúpica ou tratamento específico. Os objetivos deste estudo foram: detectar a presença do DNA e do antígeno pp65 do HCMV utilizando as técnicas de N-PCR e AGM, respectivamente, em amostras de sangue periférico de pacientes com LES; verificar o impacto clínico causado pela infecção ativa e doença por HCMV nos pacientes desta casuística; verificar a presença das imunoglobulinas IgG e IgM anti-HCMV pelo método de ELISA. Todos os pacientes apresentaram sorologia IgG-HCMV reagente. Dos pacientes estudados, 4/40 (10%) apresentaram infecção ativa pelo HCMV detectado por NPCR e/ou AGM. Destes, 3 estavam com a doença lúpica em atividade (SLEDAI ? 6). Entre os pacientes com infecção ativa pelo HCMV, 2/4 (50%) apresentaram sintomas compatíveis com doença por HCMV. Um destes pacientes foi à óbito por sepse de foco pulmonar, compatível com doença por HCMV. Apesar da infecção ativa por HCMV não ser freqüente nos pacientes com LES, quando ocorre é de extrema gravidade, podendo levar o paciente à óbito. A utilização de diagnóstico precoce da infecção ativa pelo HCMV é muito importante, pois permite um tratamento mais precoce e mais efetivo em relação ao diagnóstico sorológico, principalmente em pacientes com falha imunológica como os pacientes deste estudo / Abstract: Infectious diseases are a major cause of life-threatening in patients with rheumatic disease. The cytomegalovirus, a betaherpesvírus, is the major cause of morbidity and mortality in immunosuppressed hosts may cause fever and damage to organs such as lung, liver, gastrointestinal tract, bone marrow and retina. Patients with SLE make use of immunosuppressive and are at risk of reactivate latent infection by HCMV. The HCMV-IgG seropositive patients using immunosuppressive should be monitored using the N-PCR and/or HCMV antigenemia for the early antiviral treatment can suppress viral reactivation and consequently the associated disease. Given the foregoing, monitored 40 patients were diagnosed with Systemic Lupus Erythematosus (SLE) for the active infection by the human cytomegalovirus (HCMV) using the techniques of nested-PCR (N-PCR) and Antigenemia (AGM). It was also checked the status serum IgM and IgG anti-HCMV by ELISA. For both, were needed 2 samples of blood per patient, obtained by venipuncture. The patients were in various stages of the disease lupus or specific treatment. The objectives of this study were: to detect the presence of DNA and antigen of the pp65 HCMV using the techniques of N PCR and AGM, respectively, in samples of peripheral blood of patients with SLE; verify the clinical impact caused by active infection and disease by HCMV patients in this series; verify the presence of immunoglobulins IgG and IgM anti-HCMV by the method of ELISA. All patients had serology IgG-HCMV reagent. Of the patients studied, 4/40 (10%) had active infection by HCMV detected by N-PCR and/or AGM. Of these, 3 were in lupus activity (SLEDAI ? 6). Among patients with active infection by HCMV, 2/4 (50%) had symptoms consistent with disease by HCMV. One of these patients developed epsis with pulmonar focus and died probably by HCMV. Despite the active HCMV infection were uncommon in these patients, the outcome are othen fatal. The use of early diagnosis tests of active infection by HCMV is very important because it allows a treatment earlier and more effective in relation to the serological diagnosis, especially in patients with immunity fail as the patients in this study / Mestrado / Ciencias Basicas / Mestre em Clinica Medica

Murine cytomegalovirus (MCMV) is used as a biological model for human cytomegalovirus (HCMV). Latency, persistence and reactivation are same of the important aspects of the murine model that share analogies with human CMV infections. In order to elucidate the molecular mechanisms leading to these events, in-depth analyses of the murine model are required at the transcriptional level. During the MCMV replication cycle, there is a sequential expression of different regions of the viral genome, hence the transcripts are divided into three kinetic classes; the immediate early (IE), early (E) and late (L). This study presents the analyses of MCMV (Smith strain) transcripts of the major IE and E transcriptional units, and a more detail analysis of one of the major E regions, E10. The IE and E transcripts were studied by probing them with Ctoitplementary DNAs (cDNAs). The cDNAs were prepared from mRNA isolated from the IE and E phases of the viral replication cycle and cloned into the bacteriophage Lambda gt10. Ten E cDNAs were mapped to specific locations of the virus genome, and these represented transcripts from the major E regions in Hindlll fragments A, B, E, F, and I-J. Five E cDNAs, each representing a different major E region, and two IE cDNAs representing the major IE region, were applied as probes in one of the studies to determine the relative transcript levels during the course of infection of 3T3L1 fibroblast cells with MCMV. The major E transcriptional units were investigated further in a study where Northern blots of RNAs, isolated from different phases of the viral replication cycle, were probed with the five E cDNAs. This study revealed transcripts that were temporally regulated since they were present only during the E and usually L phases of the viral replication cycle. In addition, the quantities of these transcripts varied depending on the phase. However, all five cDNAs detected more than one transcript which indicates complex splicing events, overlapping genes, multiple initiation sites and/or the presence of gene(s) in the complementary DNA strand. One of the E cDNAs, E10, corresponding to a transcript from a major E region of Hindlll fragment I-J, was selected for further analysis. The E10 cDNA detected four transcripts of 9.5, 6.9, 4.7 and 2.1 kb in size, which were found to be transcribed from the same DNA strand. The DNA sequence of this E10 cDNA was determined and shown to contain 3223 nucleotides, however it lacked a polyadenylation signal and a poly A tract at the 3' end. The missing 3' terminus, designated as E10-A, was isolated using the polymerase chain reaction (PCJR) method and its DNA sequence of 1422 nucleotides was also determined. The combined sequence of E10 and E10-A (total of 4606 nucleotides) was designated as E10-C and is presented in this thesis. The E10-C cDNA (4.6kbp) most likely represents the 4.7 kb transcript. The E10-C cDNA sequence has one minor and one major open reading frame (ORF). The minor ORF is initiated by the first ATG triplet (nucleotide position 114) while the major ORF is initiated by the second triplet (nucleotide position 155). Since the sequence preceeding the second ATG triplet is in "good context" with regard to the translation initiation consensus sequence, it is most likely that the major ORF is translated. The major ORF (3600 bases) encodes a 1200 amino acid polypeptide, the putative E10 protein of approximately 135 kd in size. A protein close to that size was detected in one of the experiments in which RNAs, that were hybrid-selected by the E10 cDNA and eluted, were translated in vitro. The putative E10 protein lacks homology with any other protein in the data banks (SWISSPRT and GENPEPT). Portions of the viral genomic fragments Hindlll I and J were also sequenced to reveal the orientation of the gene coding for the E10 cDNA and its related transcripts. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate

The gene products produced by murine cytomegalovirus (MCMV) in infected cells prior to viral DNA synthesis are believed to control the interaction of the virus with the cells, determining whether a permissive infection results, with virus replication, or whether further virus gene expression is inhibited, resulting in a latent or abortive infection. The aim of this study was to characterize the early viral gene products that are produced in permissive and nonpermissive cells. The proteins produced in 3T3-L1 cells, permissively infected with MCMV, during the first six hours of infection (the period prior to viral DNA replication) were characterized by polyacrylamide gel electrophoresis. Ten of the proteins were classified as immediate-early (IE) and seven as early according to their time of synthesis and also according to their synthesis in the presence of actinomycin D following the reversal of a cycloheximide mediated block in protein synthesis. The estimated molecular weights ranged from 28K - 100K. The synthesis of a dominant IE protein of 100K was significantly increased, after the reversal of a cycloheximide block, compared to unenhanced conditions. The synthesis of two other major IE proteins of 96K and 89K were also significantly enhanced by this treatment. The 100K and 89K proteins partitioned with the nuclear, cytoplasmic and cytoskeletal fractions, while the 96K protein partitioned more strongly with the nuclei. These proteins were phosphorylated. The other IE proteins were synthesized in lesser amounts. The major early proteins, which had molecular weights of 39K and 36K, were also phosphorylated and were exclusively nucleus-associated. A number of the IE and early proteins had affinity for native and denatured DNA-cellulose. The same major IE and early proteins were identified in nonpermissively infected J774A.1 macrophage cells. Although 0.6% of these cells became permissively infected with MCMV and the rest appeared to be nonpermissively infected, viral DNA and late protein synthesis was not detected. The major difference between the proteins produced in 3T3-L1 cells and J774A.1 cells was the affinity of the 96K protein for denatured DNA-cellulose, which was only observed when the protein was synthesized in J774A.1 cells. The main IE and early MCMV induced proteins were also synthesized in nonpermissively infected human fibroblast cells. The only difference between the proteins produced in these cells and 3T3-L1 cells was that the 100K IE protein appeared to have a greater nuclear-affinity, when produced in the human fibroblasts, than was found when synthesized in infected 3T3-L1 cells. In conclusion, a larger number of IE and early MCMV-induced proteins were identified in infected cells than had been previously characterized. There was no evidence of restricted MCMV gene expression occurring in two different cell types that were nonpermissively infected. This appeared to indicate that, in the nonpermissive experiments described, MCMV replication was inhibited at the stage of viral DNA synthesis. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate

Orientador: Elza Cotrim Soares / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-07T13:22:52Z (GMT). No. of bitstreams: 1 Pereira_TiagoSeva_M.pdf: 1071373 bytes, checksum: b609ddc800a30649b34970b08d701972 (MD5) Previous issue date: 2006 / Resumo: A infecção é uma das complicações mais freqüentes e graves após o transplante hepático. A evolução de técnicas operatórias e mudanças nos protocolos de transplante podem ter mudado a epidemiologia e os fatores de risco para infecções após o transplante hepático. Objetivos: estudar a epidemiologia das infecções, identificar fatores de risco para infecções e verificar a influência das infecções na mortalidade após o transplante de fígado. Pacientes e métodos: estudo prospectivo de transplantados de fígado no Hospital Clínico e Provincial de Barcelona (Espanha) entre julho de 2000 e agosto de 2001. Foram coletados dados de incidência, etiologia, tipos de infecção e fatores de risco para infecção, assim como causas de mortalidade. Os fatores de risco foram identificados em análise multivariada de regressão de Cox. Resultados: Dos 81 transplantados no período de estudo, 52 (64%) tiveram infecção, sendo que 49 (60%) apresentaram 89 episódios de infecção bacteriana, metade destes nos primeiros 13 dias após o transplante. Infecções intra-abdominais (23) e urinárias (22) foram as mais comumente diagnosticadas. Bacilos Gram-negativos foram identificados em 65% das infecções com cultura positiva. Bactérias resistentes a múltiplos antibióticos estiveram presentes em 18,4% destas infecções. O citomegalovírus foi responsável por 16 (20%) episódios de infecção, que foram sintomáticos em 12. Nove (11%) pacientes tiveram infecção por fungos. Os fatores de risco independentes para infecção bacteriana foram insuficiência renal antes do transplante (RR: 2,54; p=0,004), presença de hemoperitônio (RR: 2,85; p=0,001) e anastomose biliar tipo colédoco-jejunal (RR: 2,89; p=0,015). Para infecções oportunistas virais e fúngicas, os fatores de risco encontrados foram: desenvolvimento de insuficiência renal logo após o transplante (RR: 6,29; p<0,001), necessidade de hemodiálise (RR: 9,55; p=0,016) e uso de anastomose biliar tipo colédoco-jejunal (RR: 7,34; p<0,001). Onze pacientes morreram durante o seguimento (13%), sendo 8 por causa infecciosa. Infecções oportunistas (RR: 4,5; p=0,026) e necessidade de hemodiálise (RR=99,7; p<0,001) foram os fatores de risco independentes de mortalidade. Conclusões: As infecções são, ainda, complicações freqüentes e graves no período após o transplante de fígado, e estão relacionadas a fatores cirúrgicos e insuficiência renal antes e depois do transplante / Abstract: Infection is a frequent and severe complication of liver transplantation. Recent surgical and medical advances may have influenced epidemiology and risk factors of this complication. Aims: To study the epidemiology of infection in a prospective series of liver transplant recipients and to identify predictive factors for infection and its effects on survival. Patients and methods: patients consecutively submitted to liver transplantation between July 2000 and August 2001at the Clinical Hospital of Barcelona (Spain) were prospectively followed. The study analyzed data on incidence, etiology, risk factors and mortality. Results: Eighty-one patients were prospectively followed for 16_6 months. Forty-nine patients (60%) developed bacterial infections, half of them within 2 weeks after transplantation. Intraabdominal (23) and urinary infections (22) were the most frequent demonstrated infections. Gram-negative bacilli were isolated in 65% of culture-positive infections. Multiresistant bacteria, mainly Pseudomonas aeruginosas, accounted for 18,4% of these infections. Opportunistic viral and fungal infections were diagnosed in 21 patients (26%). There were 16 cytomegalovirus infection or disease (20%) and 9 fungal infections (11%). Independent risk factors for bacterial infection were renal impairment before transplantation (RR: 2,54; p=0,004), hemoperitoneum (RR: 2,85; p=0,001), and hepaticojejunostomy (RR: 2,89; p=0,015). Early posttransplant renal impairment with (RR: 9,55; p=0,016) or without hemodialysis requirement (RR: 6,29; p<0,001) and hepaticojejunostomy (RR: 7,34; p<0,001) were predictive factors for opportunistic infections. Eleven patients died during follow-up (13%), mainly because of sepsis (8 patients). Opportunistic infections (RR: 4.5; p=0.026) and hemodialysis requirement (RR=99.7; p<0.001) were the only identified independent predictors of mortality. Conclusions: Infections are still a frequent and severe complication following liver transplantation and are related to surgical factors and poor peritransplant renal function / Mestrado / Clinica Medica / Mestre em Clinica Medica

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第17816号 / 医博第3814号 / 新制||医||999(附属図書館) / 30631 / 京都大学大学院医学研究科医学専攻 / (主査)教授 小柳 義夫, 教授 一山 智, 教授 武藤 学 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Cytomegalovirus (CMV) is the most common congenitally acquired infection. It is of major concern due to the long-term neurodevelopmental morbidity in both symptomatic and asymptomatic newborns. While CMV infection is less commonly diagnosed in infancy to adulthood, mostly due to its asymptomatic presentation, it is still an important differential to consider. A missed diagnosis could lead to visual impairments and neurological complications. Infants can acquire CMV by encountering bodily secretions from those who have an active infection. Symptoms of infection include fever, fatigue, pharyngitis, and hepatitis. Laboratory abnormalities include thrombocytopenia, elevated transaminases, and abnormal lymphocyte count. We investigated a clinical case of a previously healthy 5-month-old whose only symptoms were petechial rash and thrombocytopenia. They presented to the ED with a worsening petechial rash for 11 days. The patient’s mother had prenatal care and an uncomplicated pregnancy. In the ED IgM for CMV was positive and platelet count on admission was 35K. The patient was discharged without intervention because platelet count remained above 20K. Outpatient hematology workup ruled out other potential causes of thrombocytopenia. There is no family history of bleeding disorders. The patient was prescribed valganciclovir for 2 months and urine CMV PCR was ordered for the patient and the patient’s mother. The patient’s urine CMV was positive, but the mother’s urine CMV was negative. The patient’s petechiae and thrombocytopenia improved while on valganciclovir treatment. In this case, since the patient’s mother was negative for CMV, it is unlikely that the infection was maternally acquired. Our case illustrates that CMV infection in infancy can be acquired through horizontal transmission and its only presentation can be thrombocytopenia. Since the CMV infection was diagnosed early the patient did not have any neurological symptoms, such as sensorineural hearing loss or delayed developmental milestones.

No description available.

No description available.

Depuis plusieurs années, le rôle joué par le cytomégalovirus humain (HCMV) dans le développement des maladies inflammatoires et du cancer a été étudié par plusieurs groupes de recherche. Divers tissus tumoraux, notamment dans le cancer du colon, du foie, de la prostate, du cerveau (glioblastome, médulloblastome) et du sein, ont montré la présence d’antigènes ou d’ADN du HCMV. Cette accumulation de preuves de l'implication de l'infection par le HCMV dans les maladies malignes de diverses entités cancéreuses a conduit au développement du concept d'«oncomodulation», qui est expliqué par la capacité du HCMV à contribuer au processus d’oncogenèse, sans toutefois aucun potentiel de transformation directe. HCMV-DB (KT959235) est un isolat clinique provenant d'un échantillon de col de l'utérus d'une femme enceinte de 30 ans, préalablement isolé dans notre laboratoire. Cette souche virale a montré sa capacité à infecter les macrophages primaires et a montré une réplication productive dans les cellules épithéliales mammaires humaines (HMECs). Les HMECs infectées entraînaient l’établissement d’un environnement cellulaire pro-oncogène avec une hyperphosphorylation de Rb et une activité fonctionnelle réduite de p53, une régulation positive de c-Myc, une surexpression de l'activité télomérase et de STAT3, et une régulation positive de la cycline D1, provoquant une prolifération cellulaire accrue. En outre, HCMV-DB a montré son potentiel pour transformer les HMECs primaires par test de formation de colonies sur gélose molle, un test connu pour l’observation de la transformation cellulaire. De manière intéressante, les HMECs infectées par HCMV-DB en culture ont montré l’émergence d’amas de cellules sphéroïdes, qui ont été désignées cellules CTH (HMECs transformées par le CMV). Dans notre thèse, nous avons caractérisé le profil génomique de la souche HCMV-DB et nous l’avons comparé à des souches soit cliniques soit de laboratoire. HCMV-DB a été caractérisée comme proche des génomes des souches Toledo et JP, et cette dernière est une souche clinique isolée à partir d’un tissu glandulaire, la prostate. Nous avons également comparé les gènes impliqués dans l’entrée virale par des analyses phylogénétiques et nous avons observé la proximité de HCMV-DB avec la souche prototypique du HCMV, Merlin. En étudiant le profil transcriptomique des HMECs infectées par HCMV-DB, nous avons trouvé qu’elles présentent un phénotype basal-like triple négatif, ER-/PR-/HER2-, ainsi que des caractéristiques oncogéniques, incluant une up-régulation de l’expression de plusieurs oncogènes, de gènes pro-survie (avec down-régulation de la caspase 8), et de marqueurs de la prolifération, du caractère souche des cellules et de la transition épithélio-mésenchymateuse (EMT). Le profil transcriptomique des HMECs infectées par HCMV-DB a également montré des modifications variées dans la signalisation cellulaire, l’angiogenèse et la protéolyse. Au niveau de la chromatine, les HMECs inféctées par HCMV-DB ont révélé une hypométhylation globale. En cherchant la présence du génome de HCMV-DB dans les cellules CTH formées, nous avons détecté une signature du génome de HCMV-DB, à savoir le lncRNA4.9. Globalement, nos données ont montré que le transcriptome des HMECs infectées par HCMV-DB révèle clairement des traits pro-oncogéniques et la détection d’une partie du génome de HCMV-DB suggère que cette partie du génome viral peut être responsable de la transformation cellulaire obtenue. / Since several years, the role played by human cytomegalovirus (HCMV) in the development of inflammatory diseases and cancer has been extensively studied and addressed by different research groups. Various tumor tissues originating from colon, liver, prostate, brain (glioblastoma, medulloblastoma) and breast cancer have shown to harbor either the antigen or the DNA of HCMV. These growing evidences about the implication of HCMV infection in malignant entities had led to the emergence of the concept of “Oncomodulation”. This is explained by the ability of the virus to contribute to the oncogenic processes, however without any direct transformatory potential. HCMV-DB (KT959235) is a clinical isolate obtained from a cervical swab specimen of a 30-year-old pregnant woman previously isolated in our laboratory. This viral strain had shown its ability to infect the primary macrophages and to replicate productively in the human mammary epithelial cells (HMECs). In fact, HMECs infected by HCMV-DB resulted in the establishment of a pro-oncogenic cellular environment characterized by retinoblastoma (Rb) hyperphosphorylation and a decreased p53 functional activity, enhanced telomerase activity, upregulation of c-Myc, activation of Akt and STAT3, and upregulation of cyclin D1 causing an enhanced cellular proliferation. Furthermore, HCMV-DB had shown its potential to transform the primary HMECs by colony formation on soft agar, a well know assay to perceive transformation. Interestingly, HCMV-DB infected HMECs in culture showed the emergence of clusters of spheroid cells that were named CTH cells (CMV Transformed HMECs). In our thesis we characterized the genomic profile of HCMV-DB strain and compared it to either clinical or laboratory strains. HCMV-DB was shown to be close to the genomes of Toledo and JP strains where the JP strain is a clinical strain that was isolated from a glandular tissue, the prostate. We also compared the genes that are involved in virus entry using phylogenetic analyses and we observed that HCMV-DB is close to the prototypic HCMV strain, Merlin. By studying the transcriptomic profile of HMECs infected with HCMV-DB, we found that it displays a triple negative basal-like phenotype, ER−/PR−/HER2−, and presents oncogenic characteristics with upregulated expression of several oncogenes, pro-survival genes (with a down-regulation of caspase 8), proliferation markers, stemcellness and epithelial mesenchymal transition (EMT). The transcriptomic profile of HMECs infected with HCMV-DB also displays variant modifications in cell signaling, angiogenesis and proteolysis. At the chromatin level, HMECs infected with HCMV-DB reveals a global hypomethylation state. By screening for the presence of HCMV-DB genome in the formed CTH cells, we detected a signature of the HCMV-DB genome, namely a lncRNA4.9. Taken together, our data showed that the transcriptome of HMECs infected with HCMV-DB clearly reveals a pro-oncogenic traits and the detection of part of the HCMV-DB genome suggests that this part of the viral genome might be responsible for the obtained cellular transformation.