Given the protective roles of 25-hydroxyvitamin D (25[OH]D or vitamin D) in musculoskeletal health and the potential beneficial effects of vitamin D supplementation in reducing the risk of various chronic diseases, intensive repletion of vitamin D has been widely advocated. Of note, CD8 T cells have the highest levels of the vitamin D receptor compared with other major immune cells. The effects...

Several lines of evidence suggest that CD8 T cells are important in protection against tuberculosis. To understand the function of this cell population in the immune response against Mycobacterium tuberculosis, T cells from lungs of M. tuberculosis-infected mice were examined by flow cytometry. The kinetics of the appearance of CD8 T cells in lungs of infected mice closely paralleled that of CD...

Interleukin-15 (IL-15) is crucial for the development of naive and memory CD8 T cells and is delivered through a mechanism called transpresentation. Previous studies showed that memory CD8 T cells require IL-15 transpresentation by an as yet unknown cell of hematopoietic origin. We hypothesized that dendritic cells (DCs) transpresent IL-15 to CD8 T cells, and we examined this by developing a tr...

CD8 T cells exhibit dynamic alterations in proliferation and apoptosis during various phases of the CD8 T-cell response, but the mechanisms that regulate cellular proliferation from the standpoint of CD8 T-cell memory are not well defined. The cyclin-dependent kinase inhibitor p27(Kip1) functions as a negative regulator of the cell cycle in T cells, and it has been implicated in regulating cell...

We recently reported that NK cells and CD8(+) T cells contribute to the antimetastatic effect in the liver induced by alpha-galactosylceramide (alpha-GalCer). In the present study, we further investigated how CD8(+) T cells contribute to the antimetastatic effect induced by alpha-GalCer. The injection of anti-CD8 Ab into mice 3 days before alpha-GalCer injection (2 days before intrasplenic inje...

CD4(+) T cells promote CD8(+) T cell priming by licensing dendritic cells (DCs) via CD40-CD154 interactions. However, the initial requirement for CD40 signaling may be replaced by the direct activation of DCs by pathogen-derived signals. Nevertheless, CD40-CD154 interactions are often required for optimal CD8(+) T cell responses to pathogens for unknown reasons. Here we show that CD40 signaling...