Resident CD4+ {alpha}{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

A population of CD4⁺ cells has been identified in the murinefemale genital tract (FGT). Phenotypic studies of FGT CD4⁺ cellsdemonstrate that they express CD3 and that the majority of thesecells are ßTCR⁺Thy-1⁺. Most of the Thy-1⁺CD4⁺ßTCR⁺ cells resemble memory T cells based on their expressionof CD44, L-selectin and CD45RB antigens. The vast majority ofThy-1⁺CD4⁺ßTCR⁺ FGT cells are CD5⁺ and all of themare B220^–. Systemic stimuli including infection with Trypanosomabrucel brucel, injection with anti-CD3, or bacterial superantigensstaphylococcal enterotoxin A or B cause a rapid accumulationof CD4+cells in the FGT exceeding that observed for CD4⁺ cellsin 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 influxof cells from the circulation. The CD4⁺ population in the FGTof adult nu/nu mice is dramatically reduced, indicating itsthymic dependency. In lpr/lpr mice, FGT CD4 cells do not displaychanges characteristic of splenic or LN CD4 cells in the sameanimals. These findings demonstrate that the CD4⁺ cells of themurine FGT are thymic dependent, but that they constitute aT cell lineage that phenotypically and, probably functionally,is distinct from other peripheral CD4⁺ T cell populations.