技术资料

The presence of persistent,latent HIV reservoirs in CD4+ T cells obstructs current efforts to cure infection. The so-called kick-and-kill paradigm proposes to purge these reservoirs by combining latency-reversing agents with immune effectors such as cytotoxic T lymphocytes. Support for this approach is largely based on success in latency models,which do not fully reflect the makeup of latent reservoirs in individuals on long-term antiretroviral therapy (ART). Recent studies have shown that CD8+ T cells have the potential to recognize defective proviruses,which comprise the vast majority of all infected cells,and that the proviral landscape can be shaped over time due to in vivo clonal expansion of infected CD4+ T cells. Here,we have shown that treating CD4+ T cells from ART-treated individuals with combinations of potent latency-reversing agents and autologous CD8+ T cells consistently reduced cell-associated HIV DNA,but failed to deplete replication-competent virus. These CD8+ T cells recognized and potently eliminated CD4+ T cells that were newly infected with autologous reservoir virus,ruling out a role for both immune escape and CD8+ T cell dysfunction. Thus,our results suggest that cells harboring replication-competent HIV possess an inherent resistance to CD8+ T cells that may need to be addressed to cure infection. View Publication

Priming of human NK cells with IL-2 is necessary to render them functionally competent upon NKG2D engagement. We examined the underlying mechanisms that control NKG2D responsiveness in NK cells and found that IL-2 upregulates expression of the amino acid transporters SLC1A5 and CD98. Using specific inhibitors to block SLC1A5 and CD98 function,we found that production of IFN-γ and degranulation by CD56bright and CD56dim NK cells following NKG2D stimulation were dependent on both transporters. IL-2 priming increased the activity of mTORC1,and inhibition of mTORC1 abrogated the ability of the IL-2-primed NK cells to produce IFN-γ in response to NKG2D-mediated stimulation. This study identifies a series of IL-2-induced cellular changes that regulates the NKG2D responsiveness in human NK cells. View Publication

Human B cell antigen-receptor (BCR) repertoires reflect repeated exposures to evolving influenza viruses; new exposures update the previously generated B cell memory (Bmem) population. Despite structural similarity of hemagglutinins (HAs) from the two groups of influenza A viruses,cross-reacting antibodies (Abs) are uncommon. We analyzed Bmem compartments in three unrelated,adult donors and found frequent cross-group BCRs,both HA-head directed and non-head directed. Members of a clonal lineage from one donor had a BCR structure similar to that of a previously described Ab,encoded by different gene segments. Comparison showed that both Abs contacted the HA receptor-binding site through long heavy-chain third complementarity determining regions. Affinities of the clonal-lineage BCRs for historical influenza-virus HAs from both group 1 and group 2 viruses suggested that serial responses to seasonal influenza exposures had elicited the lineage and driven affinity maturation. We propose that appropriate immunization regimens might elicit a comparably broad response. View Publication

Events defining the progression to human type 1 diabetes (T1D) have remained elusive owing to the complex interaction between genetics,the immune system,and the environment. Type 1 interferons (T1-IFN) are known to be a constituent of the autoinflammatory milieu within the pancreas of patients with T1D. However,the capacity of IFNα/β to modulate human activated autoreactive CD8+ T-cell (cytotoxic T lymphocyte) responses within the islets of patients with T1D has not been investigated. Here,we engineer human β-cell-specific cytotoxic T lymphocytes and demonstrate that T1-IFN augments cytotoxicity by inducing rapid phosphorylation of STAT4,resulting in direct binding at the granzyme B promoter within 2 h of exposure. The current findings provide novel insights concerning the regulation of effector function by T1-IFN in human antigen-experienced CD8+ T cells and provide a mechanism by which the presence of T1-IFN potentiates diabetogenicity within the autoimmune islet. View Publication