Selection of distinct Valpha/beta T-cell receptor families during in vivo and in vitro T-cell maturation.

Abstract

The experimental conditions influencing the use of Valphabeta TCR families were examined in lymph node (LN) cells from peptide-immunized C57BL/6 and Vbeta8.2 transgenic mice. Expanded proportions of Vbeta5, Vbeta8.2, Vbeta9, Vbeta12 and Vbeta14 positive cells and an association of Vbeta8.2 with Valpha11 was found in freshly harvested 8-day or 34-day immune LN cells. In contrast, peptide-specific T-cell lines generated in vitro from 8-day immune lymph node cells were found to be almost exclusively of the Valpha2/Vbeta12 family. However, T-cell lines originating from Vbeta8.2 transgenic mice did not show preferential Valpha usage. Anti-Vbeta8.2 antibody produced different effects: when added to cultures of LN cells from C57BL/6 or Vbeta8.2 transgenic strains, the peptide-induced proliferation was suppressed; however, following the injection of mice, subsequent in vitro proliferation and cytokine production induced by both peptide and Concanavalin A was suppressed in Vbeta8.2 transgenic, but much less in C57BL/6 mice. Hence, compensatory expansion of different Vbeta gene products occurred in vivo, but not under the employed in vitro conditions. In conclusion, these results suggest that the TCR family usage is influenced by the experimental conditions in which the T cells are selected and expanded and by the genetic potentials of the precursor pool.