FIG. 3.

Induction of specific systemic Th2 response against C. trachomatis by immunization with MOMP-ISCOMs. Eight groups of mice (six mice/group) were vaccinated three times every 3 weeks with the indicated regimens, as described in Materials and Methods. The level of Th2 response induced was determined by measuring the response of chlamydia-specific, IL-4-secreting T cells from spleen cells of infected mice, as previously described (24). The amounts of IL-4 contained in supernatants derived from culture-stimulated cells and controls were measured by ELISA. The concentration of the cytokine in each sample was obtained by extrapolation from a standard calibration curve generated simultaneously. Data were calculated as the mean values (± SD) of triplicate cultures for each experiment. The control cultures without antigens did not contain detectable levels of the cytokine, and so the data were excluded from the results.