The Study Of Immune Response Of Ovary Induced By Salmonella Enteritidis In Chicken

The reproductive tract end of hens connects with cloaca, so the pathogens of the feces in cloca and environment could infect the reproductive tract, then affect on the reproductive function and the eggs. Salmonella enteritidis(SE) is one of pathogens in poultry breeding, they not only infect the intestinal tract but also invade the reproductive tract to cause the reproductive disease. SE is also the important food pathogen of zoonosis. It could contaminate the eggs and chicken. The growth and development of follicles could affect on the laying performent and the quality of egg. The ovary is not only the place where follicles grow up and develop, but also defense the SE to the chicken.There are two methods(oral SE and cloaca SE)to inoculate SE for 45 weeks chickens. HE dye was used to examninate the tissue development of ovary, Immunohistochemical method detects the populations and distribution of T lymphocytes and Bu-1+ lymphotes at 1, 4, 7, 10 and 14 day after inoculation,SYBR Green I real-time PCR method was employed in this study to investigate the expression of the TLR3, TLR4, TLR7, TLR21, IL-6 and iNOS mRNA.HE dye examninates the population of leukocytes increased in the stroma and the theca of follicle in oral SE group. There are congestion and bleeding in the vessels apart from the the population of leukocytes increased in the stroma and the theca of follicle in the cloaca group.Immunohistochemical method detect the population of CD3+ cells were significantly greater in the stroma of follicles 1 to 14 day after SE inoculation than the control birds and reacher a peak by day 14 in the oral group. While in the cloaca SE birds the numbers of CD3+ cells were significantly greater in the ovary after SE inoculation 1 to 10 day and reacher a peak by day 10 more than the control birds.CD4+ cell did not have significantly changes in these experiment group, but the time reached the peak were at the 10 day and the 4 day in oral and cloaca group, these small number of CD4+ cell distribute in the stroma and medulla of ovary. CD8+ cells reached to peak at 10 day and mainly distributed to the the stroma and the theca of follicles, sometimes the medulla in experiment groups. Although the numbers of Bu-1+ cells were lesser than T cells after SE inoculation, when compared to the control they were greater in these experiment groups.SE infection resulted in a significant induction of TLR3 mRNA at 10 day in the ovary of oral SE group,the expression of TLR3 mRNA was significantly up- regulation compared to the control group, mRNA abundance of TLR4, TLR21, IL-6 were the most at 7 day, but only the IL-6 mRNA was significantly higher than the control at 7 day, the expression of TLR7 mRNA was simiar to the contron after inculations. while the expression of TLR3 mRNA peaked at 4 day, then down-regulation in cloaca group, while a significant up- regulation was observed in the TLR7 and IL-6 ovarian mRNA compared to the control birds after the 10 day.no significant changes were observed in the expression of TLR4 and TLR21 mRNA.the abundance of iNOS mRNA peaked at 1d but no significant changes compared to the control birds, then the expression of iNOS mRNA was down- regulation in these experient group.In a word, SE could change the structure of ovary, the number of T and Bu-1+ cells also changed, but Bu-1+cells did not have significant increasing than CD3+, CD4+ and CD8+ T lymphocytes. These results indicate that SE infection could cause to immune response especially the cell immune response. By different methods of inoculation SE, the mRNA abundance of TLRs, the number and the distribution of lymphocytes in the ovary were different in these experiment groups, proved that the method of inoculation SE have an effect on the immune response for vaccine.The cloaca injection SE have a significant effect than the oral injection SE, there are the increase of cytokines in the ovary after inoculation with SE. so the results indicate that SE infection could cause to the innate immune response, but the condition were different in these experiment group, the expression of TLRs mRNA were greater than oral SE birds in cloaca SE group.