Chlamydial hsp60 and the immunopathogenesis of chlamydial disease

Chlamydia trachomatis is a major cause of ocular and genital tract infections of humans. These infections generally resolve without adverse sequelae, but occasionally severe disease develops, leading to blindness and infertility. The host immune response to chlamydial infection has long been implicated in the pathogenesis of chlamydial disease, and only recently has direct evidence supporting this hypothesis been obtained. A 57 kDa chlamydial protein (HypB), which belongs to the family of 60 kDa heat-shock proteins (hsp60), has been identified as a chlamydial constituent that stimulates this immunopathogenetic response. Here I review the present understanding of chlamydial disease pathogenesis, and discuss the possible relationship of the immune responses elicited by hsp60 to the development of the severe sequelae associated with chlamydial disease.