Chlamydia-specific lymphocytes in conjunctiva during ocular infection: limiting dilution analysis

Abstract

The immunopathogenesis of ocular infection with Chlamydia trachomatis can be investigated in the cynomolgus monkey model of trachoma. During ocular infection, both follicles (germinal centers) containing primarily B lymphocytes and a heavy perifollicular T cell infiltrate are observed. Limiting dilution analyses were performed on conjunctival and peripheral blood lymphocytes to quantify the proportion of antigen-specific cells elicited by ocular C. trachomatis infection. The frequencies of chlamydia-specific cells were 10-100 times higher in conjunctiva than in peripheral blood. Similar frequencies were observed during active infection and during the ocular delayed hypersensitivity response elicited in sensitized monkeys by topical challenge with a triton X-100 extract containing the 57 kD chlamydial stress protein. Given the antigen-specific proliferative response, these cells are most likely T lymphocytes. The finding of large numbers of antigen-specific conjunctival lymphocytes at the site of chlamydial infection suggests that they play an important role in the pathogenesis of this potentially blinding disorder.