EFFECT OF GAMMA-IRRADIATION ON THE EFFECTOR FUNCTION OF T-LYMPHOCYTESIN MICROBIAL CONTROL

A chlamydial-specific T cell clone, capable of inhibiting the growth o f infectious Chlamydia in vivo and in vitro, was employed to investiga te the effect of gamma-irradiation on the ability of effector T cells to control infections. Clone 2.14-0 (CD4(+)), specific for the Chlamyd ia trachomatis biovar agent of mouse pneumonitis (MoPn), was irradiate d with varying doses (0, 2.5, 5.0, 10.0, 20.0 and 40.0 Gy) and its bio logical functions and ability to inhibit the intraepithelial growth of MoPn were assessed. The results revealed that although gamma-irradiat ion drastically reduced the proliferative response of the clone to ant igen, it did not affect the phenotype and the effector function of inh ibiting chlamydial growth. The preservation of and-chlamydial function after gamma-irradiation correlated with the retention of IFN-gamma an d TNF-alpha secretion in response to antigenic stimulation. We conclud e that the biologic functions of T cells requiring proliferation and d ifferentiation are more likely to be adversely affected by gamma-irrad iation on the short-term, but the effector functions, possibly associa ted with cytokines and cytolysis, may be preserved among persisting ef fector T cells in an irradiated individual.