C., and G. mice immunized with MOMP, CpG, and alum showed significantly less body BYK 49187 weight loss than the corresponding control mice immunized with ovalbumin, CpG, and alum. Ten days after the challenge the BYK 49187 animals were euthanized, their lungs were weighed, and the numbers of IFU in the lungs were determined. The average weight of the lungs of the mice immunized with MOMP, CpG, and alum was significantly less than average weight of the lungs of the mice immunized with ovalbumin, CpG, and alum. Also, the average number of IFU recovered per mouse immunized with MOMP, CpG, and alum was significantly less than the average number of IFU per mouse detected in the mice inoculated with ovalbumin, CpG, and alum. In conclusion, our data show that CpG sequences Rabbit Polyclonal to Fibrillin-1 can be used as an effective adjuvant with the MoPn MOMP to elicit a protective immune response in mice against a chlamydial respiratory challenge. Members of the genus cause infections throughout the animal kingdom (2, 3, 7, 27). This genus contains four species, and three of them, at the time of delivery transmit this organism to their infants 30 to 70% of the time and may have long-term sequelae, including chronic abdominal pain, ectopic pregnancy, and infertility (29, 35). In a newborn the clinical presentation may be an ocular infection and/or a pneumonia that frequently manifests in the first 6 months of life (3, 26). In certain parts of the world is the most common cause of pneumonia in infants under 6 months old. In mature individuals pneumonia is not common, but on the other hand, is one of the most common causes of adult pneumonia (3, 26). Respiratory infections due to usually occur in individuals working in BYK 49187 close contact with infected wild birds (3, 26). Thus, the need to protect against infections is widespread throughout the world (2, 5, 8, 33). The mouse pneumonitis (MoPn) serovar was originally isolated from the lungs of mice inoculated with throat washings from humans with respiratory infections (17). This serovar was subsequently found to be a respiratory pathogen of mice, and thus, it is an ideal model to characterize potential vaccine candidates which could be used to prevent chlamydial respiratory infections (17, BYK 49187 24, 39). Optimally, a vaccine to protect against infections should induce neutralizing antibodies on the mucosal surfaces while also stimulating a strong T-cell response (15, 16, 33, 36-38). More specifically, based on recent studies with several murine models it appears that a Th1 immune response BYK 49187 is more effective than a Th2 response for protecting against a chlamydial challenge (9, 15, 16, 23). Nonreplicating antigens, including proteins such as the major outer membrane protein (MOMP), usually induce a predominant Th2 response. On the other hand, oligodeoxynucleotides containing immunostimulatory CpG motifs (CpG ODN) favor a Th1 response when they are administered to mice with a wide variety of antigens (10-13). Furthermore, CpG ODN have been found to induce significantly higher titers of antibodies against hepatitis B surface antigen, which was adsorbed to aluminum hydroxide (alum), significantly earlier in humans (H. L. Davis, C. L. Cooper, M. L. Morris, S. M. Elfer, D. W. Cameron, and J. Heathcote, Abstr. Third Annu. Conf. Vaccine Res., abstr, S25, p. 47, 2000). CpG ODN have broad effects, including stimulation of B cells to proliferate and secrete.