tailieunhanh - Báo cáo y học: "Prior exposure to an attenuated Listeria vaccine does not reduce immunogenicity: pre-clinical assessment of the efficacy of a Listeria vaccine in the induction of immune responses against HIV"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Prior exposure to an attenuated Listeria vaccine does not reduce immunogenicity: pre-clinical assessment of the efficacy of a Listeria vaccine in the induction of immune responses against HIV. | Whitney et al. Journal of Immune Based Therapies and Vaccines 2011 9 2 http content 9 1 2 JOURNAL OF IMMUNE BASED THERAPIES AND VACCINES SHORT REPORT Open Access Prior exposure to an attenuated Listeria vaccine does not reduce immunogenicity pre-clinical assessment of the efficacy of a Listeria vaccine in the induction of immune responses against HIV 3 24 5 5 James B Whitney 1 Saied Mirshahidi So-Yon Lim 1 Lauren Goins Chris C Ibegbu Daniel C Anderson Richard B Raybourne6 Fred R Frankel7 Judy Lieberman2 8 Ruth M Ruprecht2 4 Abstract Background We have evaluated an attenuated Listeria monocytogenes Lm candidate vaccine vector in nonhuman primates using a delivery regimen relying solely on oral vaccination. We sought to determine the impact of prior Lm vector exposure on the development of new immune responses against HIV antigens. Findings Two groups of rhesus macaques one Lm naive the other having documented prior Lm vector exposures were evaluated in response to oral inoculations of the same vector expressing recombinant HIV-1 Gag protein. The efficacy of the Lm vector was determined by ELISA to assess the generation of anti-Listerial antibodies cellular responses were measured by HIV-Gag specific ELISpot assay. Our results show that prior Lm exposures did not diminish the generation of de novo cellular responses against HIV as compared to Listeria-naive monkeys. Moreover empty vector exposures did not elicit potent antibody responses consistent with the intracellular nature of Lm. Conclusions The present study demonstrates in a pre-clinical vaccine model that prior oral immunization with an empty Lm vector does not diminish immunogenicity to Lm-expressed HIV genes. This work underscores the need for the continued development of attenuated Lm as an orally deliverable vaccine. Findings More than 80 of new HIV acquisitions are through mucosal routes underscoring the importance of generating HIV-specific immunity by vaccination at these .