Effects of tumor necrosis factor alpha on dendritic cell accumulation in lymph nodes draining the immunization site and the impact on the anticryptococcal cell …

SK Bauman, GB Huffnagle, JW Murphy - Infection and immunity, 2003 - Am Soc Microbiol
SK Bauman, GB Huffnagle, JW Murphy
Infection and immunity, 2003Am Soc Microbiol
Cell-mediated immune (CMI) responses and tumor necrosis factor alpha (TNF-α) have been
shown to be essential in acquired protection against Cryptococcus neoformans. Induction of
a protective anticryptococcal CMI response includes increases in dendritic cells (DC) and
activated CD4+ T cells in draining lymph nodes (DLN). During the expression phase,
activated CD4+ T cells accumulate at a peripheral site where cryptococcal antigen is
injected, resulting in a classical delayed-type hypersensitivity (DTH) reaction. Induction of a …
Abstract
Cell-mediated immune (CMI) responses and tumor necrosis factor alpha (TNF-α) have been shown to be essential in acquired protection against Cryptococcus neoformans. Induction of a protective anticryptococcal CMI response includes increases in dendritic cells (DC) and activated CD4+ T cells in draining lymph nodes (DLN). During the expression phase, activated CD4+ T cells accumulate at a peripheral site where cryptococcal antigen is injected, resulting in a classical delayed-type hypersensitivity (DTH) reaction. Induction of a nonprotective anticryptococcal CMI response results in no significant increases in the numbers of DC or activated CD4+ T cells in DLN. This study focuses on examining the role of TNF-α in induction of protective and nonprotective anticryptococcal CMI responses. We found that neutralization of TNF-α at the time of immunization with the protective immunogen (i) reduces the numbers of Langerhans cells, myeloid and lymphoid DC, and activated CD4+ T cells in DLN and (ii) diminishes the total numbers of cells, the numbers of activated CD4+ T cells, and amount of gamma interferon at the DTH reaction site. Although TNF-α neutralization during induction of the nonprotective CMI response had little effect on cellular and cytokine parameters measured, it did cause a reduction in footpad swelling when mice received challenge in the footpad. Our findings show that TNF-α functions during induction of the protective CMI response by influencing the accumulation of all three DC subsets into DLN. Without antigen stimulated DC in DLN, activated CD4+ T cells are not induced and thus not available for the expression phase of the CMI response.
American Society for Microbiology