Proliferative human T cell responses to Chlamydia trachomatis in vitro.

The T cell proliferative response to Chlamydia trachomatis was studied in otherwise healthy persons. A suspension of partially purified C. trachomatis subtype LGV-2 particles was used throughout the study. Studies of cord blood lymphocytes demonstrated that the preparation was not mitogenic. The proliferative capacity of peripheral blood mononuclear cells (PBM) and T + non-T cells from adults was tested; in about 70% a proliferative response was observed. The proliferative responses were dependent upon antigen presenting cells (APC) and were mainly mediated by T cells, even though B cells proliferated to a lesser extent. Using antigen-pulsed non-T cells as APC, a significant and consistent specific proliferative response could be obtained. High responders could be separated from low responders with different T cell concentrations. We also found that the T cell response was restricted by the HLA-D/DR determinants of the T cell donor.