SPECIFIC ANTIGENS OF CHLAMYDIA-PECORUM AND THEIR HOMOLOGS IN CHLAMYDIA-PSITTACI AND CHLAMYDIA-TRACHOMATIS

Objective-To analyze the antigenic cross reactivity of various protein s of strains of Chlamydia pecorum, C psittaci, and C trachomatis. Samp les and Procedures-Strains FC-Stra and LW-613 of C pecorum; strains B5 77, Fitz-9, and 6BC of C psittaci, and strain LGV-2 of C trachomatis w ere studied. Strains of C pecorum were propagated in Georgia bovine ki dney cells, and other chlamydial strains were propagated in L cells or Georgia bovine kidney cells. Partially purified chlamydial elementary bodies propagated in RAG cells, a BALB/c cell line cloned from a rena l adenocarcinoma of BALB/c mice, were used to immunize BALB/c mice for production of monoclonal antibodies. Rabbits were inoculated with yol k sack-propagated, purified elementary bodies to produce polyclonal an tisera. The reaction of monoclonal antibodies and polyclonal antisera with chlamydial proteins was analyzed by use of immunoblot techniques. Results-Two monoclonal antibodies reacted with a 90-kd protein of C p sittaci and a 94-kd protein of C pecorum strains. One monoclonal antib ody reacted strongly with a 67-kd protein of C pecorum and strain B577 of C psittaci, but weakly with proteins of strains 6BC and LGV-2. Ano ther monoclonal antibody reacted with a 46-kd protein of 2 C pecorum s trains and of strain B577 of C psittaci, but not with those of strains 6BC and LGV-2. Two monoclonal antibodies reacted with a 20-kd protein of C pecorum and a 22-kd protein of C psittaci and LGV-2 strains. Pol yclonal antisera reacted similarly with the proteins identified by mon oclonal antibodies in the various chlamydial strains. Conclusions-Reac tions of several monoclonal antibodies with chlamydial antigens indica ted that 67- and 46-kd proteins contain genus- and species-specific ep itopes, respectively; a 94-kd protein of C pecorum is homologous to a 90-kd protein of C psittaci and C trachomatis strains; and a 20-kd pro tein of C pecorum corresponds to a 22-kd protein of C psittaci and C t rachomatis.