Induction of abnormal Chlamydia trachomatis by exposure to interferon-gamma or amino acid deprivation and comparative antigenic analysis

Abnormal forms of Chlamydia trachomatis have been induced in vitro by a var iety of methods including nutrient deprivation, addition of cytokines and a ddition of antibiotics. These forms have been shown to have altered morphol ogy and infectivity and have been implicated in persistent infections in vi vo although there is little direct evidence for their presence. Likely site s for abnormal forms in vivo are the genital tract and the synovial tissue of reactive arthritis patients, and T cells isolated from the synovial tiss ue have been shown to be specific for chlamydial antigens, in particular th e Hsp60. Since T cell specificity is so important in reactive arthritis dis ease the antigenic composition of abnormal forms induced by Interferon-gamm a and amino acid deprivation has been examined by western blotting in two s trains of C. trachomatis belonging to different biovars. The degree of abno rmality of the organisms was found to increase as the treatments became mor e severe. No simple patterns of antigenic changes were found and difference s in the antigenic composition were seen in abnormal forms induced by the d ifferent treatments and also in the different strains. (C) 2001 Academic Pr ess.