?? T cells shape memory-phenotype ?? T cell populations in non-immunized mice.

ABSTRACT: Size and composition of ?? T cell populations change dramatically with tissue location, during development, and in disease. Given the functional differentiation of ?? T cell subsets, such shifts might alter the impact of ?? T cells on the immune system. To test this concept, and to determine if ?? T cells can affect other immune cells prior to an immune response, we examined non-immunized mice derived from strains with different genetically induced deficiencies in ?? T cells, for secondary changes in their immune system. We previously saw extensive changes in pre-immune antibodies and B cell populations. Here, we report effects on ?? T cells. Similarly to the B cells, ?? T cells evidently experience the influence of ?? T cells at late stages of their pre-immune differentiation, as single-positive heat stable antigen-low thymocytes. Changes in these and in mature ?? T cells were most prominent with memory-phenotype cells, including both CD8+ and CD4+ populations. As previously observed with B cells, most of the effects on ?? T cells were dependent on IL-4. Unexpectedly, IL-4 seemed to be produced mainly by ?? T cells in the non-immunized mice, albeit strongly regulated by ?? T cells. Similarly to our findings with B cells, changes of ?? T cells were less pronounced in mice lacking all ?? T cells than in mice lacking only some, suggesting that the composition of the ?? T cell population determines the nature of the ??-influence on the other pre-immune lymphocytes.

SUBMITTER: Phalke SP 

PROVIDER: S-EPMC6592556 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature