Murine CMV (MCMV) establishes a systemic, low-level persistent infection resulting in the accumulation of CD8(+) T cells specific for a subset of viral epitopes, a process called memory inflation. Although replicating virus is rarely detected in chronically infected C57BL/6 mice, these inflationary cells display a phenotype suggestive of repeated Ag stimulation, and they remain functional. CD4(...

In chronic viral infections, persistent antigen presentation causes progressive exhaustion of virus-specific CD8+ T cells. It has become clear, however, that virus-specific naïve CD8+ T cells newly generated from the thymus can be primed with persisting antigens. In the setting of low antigen density and resolved inflammation, newly primed CD8+ T cells are preferentially recruited into the func...

Chronic infections in mice can result in defects in memory CD8 T cell properties including low expression of the IL-7Ralpha (CD127). To determine whether defects in memory CD8 T cell formation exist during human chronic infections and to what extent these defects may be allele- or epitope-specific, we compared influenza (Flu), vaccinia (VV) and EBV-specific CD8 T cells to HIV-specific CD8 T cel...

Contact hypersensitivity (CHS) is a T cell-mediated response to hapten sensitization of the epidermis. The roles of CD4+ and CD8+ T cells in CHS have remained unclear, however, as studies to define either subset as the T cells mediating CHS have provided conflicting results. The goal of this study was to correlate the in vivo function of CD4+ and CD8+ T cells in CHS with the cytokines produced ...

IL-6 is known to contribute to the differentiation of CD4+ T cells into different subsets of effector T helper cells. Less is known about the potential of IL-6 in regulating CD8+ T cell effector function. Here, we identify IL-6 as a master regulator of IL-21 in effector CD8+ T cells. IL-6 promotes the differentiation of a subset of naive CD8+ T cells that express IL-6R into a unique population ...

considering the emerging importance of phenotypic markers as indicators of cell function and differentiation, we studied patterns ofcd44 and cd45rb expression in cd8+ murine t cells with prior exposure to antigen or staphylococcal enterotoxin b ( seb ). following in vivo priming with two purified protein derivatives (one from a virulent who strain and the other from an avirulent strain), t cell...

Both CD4(+) T cell help and IL-2 have been postulated to "program" activated CD8(+) T cells for memory cell development. However, the linkage between these two signals has not been well elucidated. Here we have studied effector and memory CD8(+) T cell differentiation following infection with three pathogens (Listeria monocytogenes, vesicular stomatitis virus, and vaccinia virus) in the absence...

Humanized mice are expected to be useful as small animal models for in vivo studies on the pathogenesis of infectious diseases. However, it is well known that human CD8(+) T cells cannot differentiate into effector cells in immunodeficient mice transplanted with only human CD34(+) hematopoietic stem cells (HSCs), because human T cells are not educated by HLA in the mouse thymus. We here establi...

The main adaptive immune response to bacteria is mediated by B cells and CD4+ T-cells. However, some bacterial proteins reach the cytosol of host cells and are exposed to the host CD8+ T-cells response. Both gram-negative and gram-positive bacteria can translocate proteins to the cytosol through type III and IV secretion and ESX-1 systems, respectively. The translocated proteins are often essen...