Human cytomegalovirus (HCMV) is a betaherpesvirus that infects up to 80% of the population worldwide, and establishes latency in monocytes and bone marrow cells. Reactivated HCMV can become an opportunistic pathogen in individuals who are immunocompromised, such as those with acquired immunodeficiency syndrome (AIDS). HCMV infection of AIDS patients causes a sight-threatening retinitis that leads to vision loss and blindness in up to 46% of this population without antiretroviral treatment. Because untreated HIV-infected individuals exhibit the loss of cell-mediated immunity and alterations in CD4+ T-helper (Th) cell cytokines, including elevation of interleukin-4 (IL-4), IL-10, and IL-17, we sought to test the hypothesis that these cytokines play key roles in governing the susceptibility to AIDS-related HCMV retinitis. This hypothesis was tested utilizing a clinically relevant mouse model of experimental murine cytomegalovirus (MCMV) retinitis that occurs in C57BL/6 mice immunosuppressed by mouse retroviruses (MAIDS). Studies revealed that MAIDS progression was associated with increased levels of IL-4 and IL-10, cytokines whose production has been associated with diminished CD8+ T-cell-mediated immunity during HIV infection. However, MCMV–infected eyes of retinitis-susceptible IL-4-/- or IL-10-/- MAIDS mice exhibited frequency and severity of retinitis and viral titers equivalent to MCMV-infected eyes of wild-type MAIDS animals. These studies indicated that neither IL-4 nor IL-10 alone play key roles in increased susceptibility to MCMV retinitis. In comparison, IL-17, an inflammatory cytokine associated with the ocular autoimmune disease uveitis, was systemically increased during the progression of MAIDS, but MCMV-infected eyes of retinitis-susceptible MAIDS mice exhibited a significant reduction in IL-17. These findings suggested that IL-17 plays no direct role in the pathogenesis of experimental MCMV retinitis. However, these results also suggested the remarkable possibility that MCMV downregulates IL-17 production, a hypothesis supported by the observation that systemic MCMV infection of healthy and MAIDS mice resulted in the downregulation of IL-17. Mechanistic studies revealed that knockdown of IL-10 resulted in a partial recovery IL-17 levels during MCMV infection. We conclude that MCMV-induced IL-17 downregulation occurs via the stimulation of IL-10 and the suppressor of cytokine signaling (SOCS)-3. Taken together, our results add new information to the immunobiology of HCMV and to our basic understanding of the pathogenesis of AIDS-related HCMV retinitis.

The human cytomegalovirus (CMV) is one of the viruses which extensively infect in the world. In order to grow and reproduce, the CMV invades designated cellular lives and influences their behavior. The origin of replication (also called the replication origin) is a particular sequence in the CMV DNA genome at which replication is initiated. In this study, we develop some statistical tests of complementary palindromes, which can be applied to narrow the search for replication origin of the CMV DNA sequence. Let X_(2k) be the number of complementary palindromes with length 2k and Y_(2k) be the number of non-covered complementary palindromes with length 2k inside a given DNA sequence. Consider the null hypothesis that the marginal probabilities of the four nucleotides remain the same (1/4) over the given sequence versus the alternative hypothesis that the marginal probabilities are different. The likelihood ratio test based on the joint distributions of Y_(18) and Y_(2k) | (Y_(2(k+1)), ...,Y_(18)), where k=1, ..., 8, under the null and the alternative hypotheses are derived. The null distribution of the test statistic is approximated by a scaled chi-squared distribution. The scale parameter and the degree of freedom are estimated by the method of moments. The Pearson's chi-squared test based on the marginal distributions of X_(2k), where k=1, ..., 9. The null distribution of the test statistic is also approximated by a scaled chi-squared distribution. There is an another focus about ratios statistics X_(2k)/X_(2(k+1)) and Y_(2k)/Y_(2(k+1)), which approximate a specific value under the null hypotheses. Simulation studies are performed to confirm the theoretical findings.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 89-99).

No description available.

Human cytomegalovirus (CMV) is a significant infectious agent causing disease in immunocompromised HIV-infected patients, transplant recipients, and neonates. The current antiviral therapeutic strategy against CMV is limited in its utility due to the inherent toxicity and lack of bioavailability of currently available anti-CMV agents, ganciclovir (GCV), cidofovir (CDV), and foscarnet (FOS). The development of the prodrug of GCV, valganciclovir (val-GCV), has vastly improved the bioavailability profile of GCV. However, val-GCV demonstrates limited effectiveness against tissue-invasive CMV diseases as side effects involved with traditional intravenously administered GCV such as haematologic and reproductive toxicities remain. In addition, the emergence of antiviral resistant CMV mutant strains due to prolonged treatment with currently available antivirals necessitates the development of novel anti-CMV agents with reduced toxicity and improved bioavailability. In this study, select groups of novel compounds were analysed for their potential for further development as anti-CMV agents. Three groups of compounds were identified based on two screening methods which included the computer simulated screening process of compounds known as in silico screening and the traditional method of random screening. The first group of compounds (CATi) were identified by in silico screening against the CMV DNA polymerase catalytic aspartate triad, resulting in the identification of 31 compounds with the potential for inhibitory activity against CMV. The second group of compounds (PRO-i) were identified through in silico screening against the CMV protease, identifying a total of 18 lead compounds exhibiting structural complementarity with CMV protease. The third and final group of compounds (TPEX) were identified through random screening and consisted of plant extracts purified from tropical plants. All three compounds were initially screened for cytotoxicity against human fibroblasts. Plaque reduction assays were performed using compounds with acceptable levels of cytotoxicity to determine the ability of the compounds to inhibit the replication of the laboratory antiviral sensitive CMV strain, Towne. Two of the PRO-i compounds demonstrated good antiviral activity against CMV. Eleven percent (2/18) of the PRO-i compounds inhibited CMV replication, with PRO-i-43 and PRO-i??-44 displaying mean 50% inhibitory concentrations (IC50) of 4.8 ?? 1.2 ??M and 8.04 ??M, respectively. PRO-i-43 and PRO-i-44 are thus good candidates for further development as novel antiviral agents against CMV. The majority of CATi and TPEX compounds displayed significant cytotoxicity against human fibroblasts and compounds with acceptable levels of cytotoxicities did not significantly inhibit CMV replication. However, the identification of compounds with low cytotoxicities provides a good foundation for further development of novel anti-CMV agents with superior antiviral activity. In silico screening against three-dimensional viral protein models is a useful strategy for the identification of novel antiviral agents with the potential for inhibitory activity against CMV. Structural modification to produce potent derivatives of the identified anti-CMV compounds (PRO-i-43 and PRO-i-44) is a good option for the further development of novel antiviral agents against CMV. Such further examination of the identified compounds with anti-CMV activity is required to investigate their activity against not only antiviral sensitive CMV strains but also resistant CMV strains. Further investigations will yield new insights into their target, allowing further identification of compounds with potential anti-CMV activity with pharmaceutical application.

Diss. (sammanfattning) Uppsala : Univ., 2003. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed Sept. 16, 2008). Includes bibliographical references.

Thesis (Ph. D.) -- University of Texas Southwestern Medical Center at Dallas, 2005. / Vita. Bibliography: 152-170.

Objetivo: comparar a profilaxia universal com a terapia preemptiva com ganciclovir endovenoso no manejo da citomegalovirose em pacientes transplantados de pulmão em uma coorte retrospectiva. Metodologia: de março de 1999 a dezembro de 2009 foram estudados, no Serviço de Transplante do Complexo Hospitalar Santa Casa de Porto Alegre, todos os pacientes submetidos a transplante pulmonar, procurando-se verificar a ocorrência de citomegalovirose relacionada ao tipo de tratamento profilático anti-viral utilizado (universal e preemptiva). Foram excluídos, em ambos os grupos, os pacientes nos quais não tivesse sido registrada a antigenemia no primeiro mês após o transplante, e os que foram a óbito dentro dos primeiros trinta dias após a cirurgia. Resultados: de 224 pacientes transplantados no período referido, 66 (29,5%) foram excluídos por óbito precoce. Os 158 pacientes que entraram no estudo tinham idade de 51±15 anos (7 anoa-71 anos), e 61,0% eram do sexo masculino; 150 (95%) receberam o órgão de doador cadavérico, e 134 (85,0%) foram submetidos a transplante unilateral. A profilaxia universal para citomegalovirus (CMV) foi realizada em 70 pacientes (44,0%) e a terapia preemptiva em 88 (56,0%). O grupo que recebeu profilaxia universal levou maior tempo para positivar o exame (p<0.001) comparado com o grupo que não a recebeu. Houve associação significativa entre profilaxia e antigenemia positiva no primeiro ano após o transplante (p=0.024). A mortalidade no primeiro e no quinto ano foi respectivamente de 20% e 50%. A sobrevida mediana do grupo com profilaxia universal foi 3.8 anos (IC95% de 2.5 a 5.0) e o grupo com terapia preemptiva de 4,3 anos (IC95% de 2.5 a 6.0), não apresentando diferença significativa. Conclusão: com base nos dados obtidos neste estudo a profilaxia universal e a terapia preemptiva demonstraram-se seguras e efetivas, entretanto os achados desta pesquisa não se demonstraram conclusivos para definir a melhor opção terapêutica. / Objective: To compare the universal prophylaxis and preemptive therapy for the treatment of cytomegalovirus in lung transplant patients in a retrospective cohort. Method: Performed at the Lung Transplant service in Santa Casa de Porto Alegre during the period from March 1999 to December 2009, upon reviewing the records and results of cytomegalovirus detection. Were excluded in both groups the patients who were not registered antigenemia in the first month after lung transplantation, due to death during this period. Results: 224 patients transplanted during the study period, 66 patients were excluded due to death within 30 days after transplantation. Mean age of patients was 51 ± 15 years old, 61.0% were men, 95.0% received organ of cadaveric donors, 85.0% were submited to unilateral transplant. The universal prophylaxis was performed in 44.0% of patients and preemptive therapy in 56.0%. The group receiving prophylaxis universal took longer to make positive antigenemia (p <0.001) when compared with the group not receiving prophylaxis. It was observed significant association between positive antigenemia and prophylaxis in the first year after transplantation (p = 0.024). The general mortality in the first and fifth year was 20.0% and 50.0% respectively. Survival of patients with prophylaxis presented a median of 3.8 (95% CI 2,5 to 5.0) years and the group that received no prophylaxis had a survival of 4,3 years (95% CI 2.5 to 6.0). Conclusion: Based on the data obtained in this study universal prophylaxis and preemptive therapy demonstrated to be safe and effective, however the findings of this research did not prove conclusive to determine the best treatment.

Le cytomégalovirus humain (CMVH) est un pathogène opportuniste majeur en cas d’immunodépression et représente la principale cause d’infection congénitale d’origine virale. Bien qu’efficaces, l’utilisation des molécules conventionnelles est limitée par l’émergence de résistance et leur toxicité. Il devient alors nécessaire de développer de nouveaux traitements.L’étude des nouvelles mutations émergeant sous traitement antiviral demeure donc essentielle. L’introduction de ces nouvelles mutations, par mutagénèse « en passant », dans un chromosome bactérien artificiel contenant le génome viral nous permet, après transfection en cellules humaines, de tester la sensibilité de la souche recombinantes aux antiviraux.Différentes mutations de résistances ont ainsi été caractérisées. Afin de mettre en évidence de nouvelles cibles antivirales, des analyses bio-informatiques et la production de virus recombinants ont permis d’identifier de potentiels motifs fonctionnels essentiels à la réplication au sein du complexe terminase et hélicase-primase. Ainsi, nous avons montré quela sous-unité pUL56 du complexe terminase appartient à la famille des LAGLIDADG Homing Endonuclease. En effet, pUL56 contient un motif LATLNDIERFL et un motif de liaison à l’ADN. La technologie Alpha utilisant des protéines purifiées a permis de valider le caractère essentiel du fragment WMVVKYMGFF de pUL56 pour l’interaction avec pUL89. Enfin, nous avons mis en évidence les résidus impliqués dans la fixation de l’ATP au sein de l’hélicase et dans la stabilisation du zinc de la primase. Ainsi, la compréhension de la structure de ces protéines pourrait permettent de mieux appréhender leur fonctionnement au sein du processus de réplication du CMVH et le développement de nouvelles thérapies ciblant ces domaines. / Human cytomegalovirus (HCMV) is an important opportunistic pathogen for immunecompromised patients and is the leading cause of congenital viral infection. Although they are effective, using of conventional molecules is limited by the emergence of resistance and their toxicity. Then it becomes necessary to develop new treatments. Study of new mutationsemerging under antiviral treatment is therefore essential. Introduction of these new mutations, by « en passant » mutagenesis, into an artificial bacterial chromosome containing the viral genome allows us, after transfection into human cells, testing antivirals sensitivity of the recombinant. Different mutations of resistances have been characterized. In order tohighlight new antiviral targets, bioinformatics and recombinant viruses production allowed to identify potential functional patterns essential for viral replication within terminase and helicase-primase complex. Thus, we have shown that pUL56 subunit of the terminase complex belongs to the LAGLIDADG Homing Endonuclease family. Indeed, pUL56 contains aLATLNDIERFL motif and a DNA binding motif. Alpha technology using purified proteins allowed to validate the essential character of the WMVVKYMGFF fragment of pUL56 for the interaction with pUL89. Finally, we highlighted the residues involved in ATP binding within the helicase and in the stabilization of zinc within the primase. Thus, understanding of these proteins structure could allow us to better understand their role within the viral replication process and the development of new therapies targeting these domains.