Immunity to chlamydial infections of the eye. III. Presence and duration of delayed hypersensitivity to guinea pig inclusion conjunctivitis

Guinea pig inclusion conjunctivitis, a chlamydial infection of the eye, induced systemic, delayed hypersensitivity as measured by skin testing and by the macrophage-migration inhibition (MI) assay. Four to 6 days after infection positive skin reactions marked the onset of delayed hypersensitivity. Skin reactions were larger and more positive from days 11 through 83 post-infection; smaller and less positive reactions were observed on days 350 to 850. The results of the MI assay correlated well with skin tests. Circulating and eye secretion antibodies appeared by day 11 and were still present in low titers by day 850. These results indicate that the ocular, chlamydial infection induced long lasting, systemic responses in the circulating, secretory, and cell-mediated immune systems. The role of cell-mediated immunity in resistance to chlamydial reinfection of the eye is discussed.