PLoS ONE (Jan 2019)

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

  • Swati Popat Phalke,
  • Yafei Huang,
  • Kira Rubtsova,
  • Andrew Getahun,
  • Deming Sun,
  • Richard L Reinhardt,
  • Rebecca L O'Brien,
  • Willi K Born

DOI
https://doi.org/10.1371/journal.pone.0218827
Journal volume & issue
Vol. 14, no. 6
p. e0218827

Abstract

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Size and composition of γδ T cell populations change dramatically with tissue location, during development, and in disease. Given the functional differentiation of γδ T cell subsets, such shifts might alter the impact of γδ T cells on the immune system. To test this concept, and to determine if γδ 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 γδ 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 αβ T cells. Similarly to the B cells, αβ T cells evidently experience the influence of γδ T cells at late stages of their pre-immune differentiation, as single-positive heat stable antigen-low thymocytes. Changes in these and in mature αβ 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 αβ T cells were dependent on IL-4. Unexpectedly, IL-4 seemed to be produced mainly by αβ T cells in the non-immunized mice, albeit strongly regulated by γδ T cells. Similarly to our findings with B cells, changes of αβ T cells were less pronounced in mice lacking all γδ T cells than in mice lacking only some, suggesting that the composition of the γδ T cell population determines the nature of the γδ-influence on the other pre-immune lymphocytes.