We previously showed that humanized immune system (HIS) mice generated in Balb/c Rag2^-/-γ_c^-/- SIRP^NOD (BRGS) recipients are susceptible to HIV-1 infection (X4 and R5 isolates) and maintain circulating HIV-1 in the plasma, resulting in a dramatic depletion of human CD4⁺ T cells. We also characterized features of HIV physiopathology in this model. Human thymocyte subsets developing in the thymus of HIS mice appear phenotypically normal, but in the periphery the T cell repertoire is restricted compared with that of human peripheral blood T cells. This negatively impacts on the ability of HIS mice to generate antigen-specific human immune responses when mice are vaccinated with protein antigens or following infection with lymphotropic viruses such as HIV. One likely explanation for these functional deficiencies involves the fact that human T cells are selected intrathymically by mouse MHC molecules and that naïve T cells in peripheral lymphoid organs interact primarily with mouse DC (as human DC development in HIS mice is limited). As a first line of improvement, we recently generated a novel mouse model by crossing our BRGS mice with the HLA-A*02-HHD class I transgenic mice and the HLA-DRB1*15 class II transgenic mice, resulting in BRGS-A2DR2 mice. Following intra-hepatic injection of these mice with MHC-matched CD34⁺ stem cells we observed increased engraftment, with faster kinetics. Moreover BRGS-A2DR2 HIS mice have an increased T cell development leading to a more equilibrated B/T and CD4/CD8 phenotype. We showed that BRGS-A2DR2 HIS mice were able to sustain replication of HIV R5 virus as the BRGS hosts. Viremia was similar in a first phase and then lower in a second phase in BRGS-A2DR2 compared to BRGS HIS mice, which could be a consequence of a better quality of the immune response. However, the viremia reached a similar plateau in the last phase. We propose to study the impact of the immune res

The present work is to systematically investigate the role of TLRs and NODs in the host defense during C. trachomatis infection using KO animals. The inflammatory cytokines and bacterial burden will be measured using Bio-Plex ELISA kit. C3BI will provide help in the data analysis.

Taking advantage of a murine model of controlled microbiota composed of 12 strains, we evaluated the activity of a cocktail of three virulent bacteriophages to target a murine Escherichia coli strain in the mammalian gut.