Ocular Delayed Hypersensitivity: A Pathogenetic Mechanism of Chlamydial Conjunctivitis in Guinea Pigs

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 83; no. 19; pp. 7480 - 7484
• Main Authors: Watkins, Nancy G., Hadlow, William J., Moos, Abbie B., Caldwell, Harlan D.
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 01.10.1986; National Acad Sciences
• Subjects: Allergens; Animals; Antigens, Bacterial - immunology; Bacteriology; Biological and medical sciences; Chlamydia Infections - immunology; Chlamydia trachomatis; Conjunctiva; Conjunctiva - immunology; Conjunctivitis, Bacterial - immunology; Conjunctivitis, Inclusion - immunology; Delayed hypersensitivity; Eye diseases; Female; Fundamental and applied biological sciences. Psychology; Guinea Pigs; Histology; Hot Temperature; Hypersensitivity; Hypersensitivity, Delayed - immunology; Immunity; Immunity, Cellular; Infections; Microbiology; Pathogenesis; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Trachoma; Chlamydiaceae; Pathogenesis; Rodentia; Chlamydia psittaci; Delayed hypersensitivity; Conjunctivitis; Mechanism; Vertebrata; Eye disease; Mammalia; Guinea pig; Animal; Chlamydiales; Bacteria
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.83.19.7480

We used a naturally occurring, Chlamydia psittaci-caused eye disease in guinea pigs, guinea pig inclusion conjunctivitis, as an animal model to understand both the immune response and the pathogenesis of chlamydial eye infections. When instilled into the conjunctival sac of guinea pigs that had been previously infected and were immune, viable chlamydiae or a Triton X-100-soluble extract of them produced a short-lived (12-48 hr) eye disease indistinguishable clinically and histologically from that observed during primary chlamydial eye infection. The clinical and histologic findings were consistent with those of ocular delayed hypersensitivity. Ocular delayed hypersensitivity was induced by primary chlamydial infection at mucosal sites other than conjunctival, such as vaginal and intestinal. Preliminary characterization of the hypersensitivity allergen shows that it is heat sensitive and common to the genus Chlamydia. The allergen is apparently not surface-exposed on chlamydiae and requires viable but not replicating organisms for activity. Our observation should be useful in understanding pathogenetic mechanisms of Chlamydia trachomatis-caused infections in humans, in particular those that produce chronic inflammatory diseases, such as blinding trachoma and urogenital diseases.