RESIDENT CD4(-BETA T-CELLS OF THE MURINE FEMALE GENITAL-TRACT - A PHENOTYPICALLY DISTINCT T-CELL LINEAGE THAT RAPIDLY PROLIFERATES IN RESPONSE TO SYSTEMIC T-CELL ACTIVATION STIMULI() ALPHA)

A population of CD4(+) cells has been identified in the murine female genital tract (FGT), Phenotypic studies of FGT CD4(+) cells demonstrat e that they express CD3 and that the majority of these cells are alpha beta TCR(+)Thy-1(+), Most of the Thy-1(+)CD4(+)CD4(+)alpha beta TCR() cells resemble memory T cells based on their expression of CD44, L-s electin and CD45RB antigens, The vast majority of Thy-1(+)CD4(+)alpha beta TCR(+) FGT cells are CD5(+) and all of them are B220(-). Systemic stimuli including infection with Trypanosoma brucei brucei, injection with anti-CD3 epsilon, or bacterial superantigens staphylococcal ente rotoxin A or a cause a rapid accumulation of CD4(+) cells in the FGT e xceeding that observed for CD4(+) cells in spleen and lymph nodes (LN) , Expansion of the FGT CD4(+) cells, which are phenotypically distinct from the splenic and LN CD4(+) T cells, is due to local proliferation rather than an influx of cells from the circulation, The CD4(+) popul ation in the FGT of adult nu/nu mice is dramatically reduced, indicati ng its thymic dependency, In lpr/lpr mice, FGT CD4 cells do not displa y changes characteristic of splenic or LN CD4 cells in the same animal s, These findings demonstrate that the CD4(+) cells of the murine FGT are thymic dependent, but that they constitute a T cell lineage that p henotypically and, probably functionally, is distinct from other perip heral CD4(+) T cell populations.