Antigen-dependent and-independent mechanisms of T and B cell hyperactivation during chronic HIV-1 infection

A Haas, K Zimmermann, A Oxenius - Journal of virology, 2011 - Am Soc Microbiol
A Haas, K Zimmermann, A Oxenius
Journal of virology, 2011Am Soc Microbiol
Continuous loss of CD4+ T lymphocytes and systemic immune activation are hallmarks of
untreated chronic HIV-1 infection. Chronic immune activation during HIV-1 infection is
characterized by increased expression of activation markers on T cells, elevated levels of
proinflammatory cytokines, and B cell hyperactivation together with
hypergammaglobulinemia. Importantly, hyperactivation of T cells is one of the best predictive
markers for progression toward AIDS, and it is closely linked to CD4+ T cell depletion and …
Abstract
Continuous loss of CD4+ T lymphocytes and systemic immune activation are hallmarks of untreated chronic HIV-1 infection. Chronic immune activation during HIV-1 infection is characterized by increased expression of activation markers on T cells, elevated levels of proinflammatory cytokines, and B cell hyperactivation together with hypergammaglobulinemia. Importantly, hyperactivation of T cells is one of the best predictive markers for progression toward AIDS, and it is closely linked to CD4+ T cell depletion and sustained viral replication. Aberrant activation of T cells is observed mainly for memory CD4+ and CD8+ T cells and is documented, in addition to increased expression of surface activation markers, by increased cell cycling and apoptosis. Notably, the majority of these activated T cells are neither HIV specific nor HIV infected, and the antigen specificities of hyperactivated T cells are largely unknown, as are the exact mechanisms driving their activation. B cells are also severely affected by HIV-1 infection, which is manifested by major changes in B cell subpopulations, B cell hyperactivation, and hypergammaglobulinemia. Similar to those of T cells, the mechanisms underlying this aberrant B cell activation remain largely unknown. In this review, we summarized current knowledge about proposed antigen-dependent and -independent mechanisms leading to lymphocyte hyperactivation in the context of HIV-1 infection.
American Society for Microbiology