RECALL OF ORIGINAL SEROLOGIC RESPONSE AFTER CHALLENGE WITH HOMOLOGOUSAND HETEROLOGOUS CHLAMYDIA-TRACHOMATIS SEROVARS

Chlamydia trachomatis serovar-specific major outer membrane protein (M OMP) antigens are important targets of immune neutralization in vitro, and natural immunity to infection is associated with serovar specific ity. Reinfection, often by different serovars, plays an essential role in chlamydial disease pathogenesis. By use of a murine model, the ana mnestic serologic response was characterized following priming and cha llenge inoculations using 6 different serovars. The serologic response was evaluated using synthetic peptides representing MOMP variant segm ents (VS) 1, 2, 3, and 4 antigenic regions for each of the 6 serovars. One year after a single priming inoculation, challenge with the same serovar resulted in serologic responses to homologous VS1 peptides. Af ter challenge with a different serovar, anti-VS1 serologic responses w ere often elicited with specificity to both the priming serovar and th e challenge serovar, The recall of serologic response to the original serovar was typically dependent upon the antigenic relationship of the 2 serovars.