The Expression Of Host TLRs And The Secretion Of Cytokines Induced By Eimeria Tenella With Viruses

Coccidiosis, caused by the parasites of the genus Eimeria(phylum Apicomplexa), is one of the most severe poultry diseases worldwide, it can seriously do harm to the development of the poultry industry. Coccidiosis was listed as one of the five most serious hazards of the disease of poultry by the US Department of Agriculture. Coccidiosis causes large economic losses in our country and the worldwide to poultry industry.Toll-like receptors(TLRs), a highly conserved family of proteins, and play important roles in the reduction and clearance of pathogens through recognize pathogen by initiating host immune responses. At least ten of TLR genes have been identified in the chicken, among them Ch TLR3, Ch TLR7 and Ch TLR21 are the receptors to recognize virus. Zhou(2011), Qin(2012) and Zhang(2012) et al has shown that E.tenella can be recognized by the host innate immune system during infection, and cause a variety change of Ch TLRs expression. Han et al(2011) found virus-like particles in E.tenella for the first time, Wu et al(2016) had decode the genome of the viruses of E.tenella. The existence of virus-like particles may affect innate immune system of host to recognize E.tenella. Currently, the induced of host TLRs expression by E. tenella with viruses infection has not been reported. This experiment studies E.tenella with viruses and without viruses induced the expression of host TLRs and the secretion of inflammatory cytokine, as well as the lesion of cecum in chicken, to preliminary determined the effect of E.tenella with viruses on the activation of TLRs signalling pathway of innate immune response and to lay a good foundation for defining the innate immune mechanism of hosts infected with E.tenella.This article mainly including the following contents:The Ch TLRs m RNA expression changes of chicken macrophages induced by Eimeria tenella with viruses and Eimeria tenella without viruses.Stimulate chicken macrophages with E.tenella with viruses and E.tenella without viruses, collected the chicken macrophages at different time(0, 1, 2, 4, 6, 8h) respectively and extracted total RNA, then checked the dynamic changes of the expression of Ch TLRs by q RT-PCR. The results showed that after chicken macrophages were stimulated with E.tenella with viruses, the expression of Ch TLR1, 4, 7, 15, 21 m RNA up-regulated. The expression level of Ch TLR2, 3, 5 m RNA decreased. After chicken macrophages were stimulated with E.tenella without viruses, the expression of Ch TLR1, 4, 15, 21 m RNA up-regulated. The expression level of Ch TLR2, 3, 5, 7 m RNA decreased. In conclusion, stimulate chicken macrophages with E.tenella with viruses and E.tenella without viruses induced the dynamic changes of multiple Ch TLRs. Compared with the group that E.tenella without viruses, Ch TLR3 m RNA expression level significantly increase at 8h of the group of E.tenella with viruses. Ch TLR7 expression level increase in group of E.tenella with viruses, on the contrary to the group of E.tenella without viruses. Ch TLR21 expression level obvious increase in group of E.tenella with viruses than the group of E.tenella without viruses. It is shown that Ch TLR3, Ch TLR7, Ch TLR21 may be related to the innate immune response of chicken to resistance the viruses of E.tenella.The Ch TLRs m RNA expression changes of chicken cecum after the chicken infected with Eimeria tenella with viruses and Eimeria tenella without viruses.Infected the chicken with E.tenella with viruses and E.tenella without viruses respectively, setting control group. Detection the Ch TLRs m RNA expression changes of the chicken cecum at different time(2h, 6h, 12 h, 24 h, 48 h, 72h) after infected by q RT-PCR. The results show that both groups can induce multiple Ch TLRs m RNA expression level dynamic change in the epithelial cells of cecum,including Ch TLR1, 2, 3, 4, 5, 7, 15, 21. Excepted Ch TLR3, after the chicken infected with E.tenella with viruses, Ch TLR1, 2, 4, 5, 7, 15, 21 m RNA expression level reaches its maximum at 6h. After the chicken infected with E.tenella without viruses, Ch TLR1, 2, 4, 5, 7, 15, 21 m RNA expression level reaches its maximum at 24 h. The differences of time showed that infected with E.tenella with viruses caused earlier immune response than that infected with E.tenella without viruses. The group that infected with E.tenella with viruses, m RNA expression level of Ch TLR3 increasing reaches its maximum at 24 h after infection. Ch TLR3, Ch TLR7 and Ch TLR21, which is receptors to recognize virus, its change may relate to innate immune response in the chicken resistance viruses of E.tenella.The secretion of IL-6 and IFN-βand the observation of cecum lesion when chicken infected with E.tenella with viruses and E.tenella without viruses.Collected the sera of chicken which infected with E.tenella with viruses and E.tenella without viruses, then detected the secretion level of IL-6 and IFN-β by ELISA, and made paraffin section to cecum of chicken for observation the lesions. The results showed that the chicken infection with E.tenella with viruses and E.tenella without viruses, both IL-6 and IFN-β up-regulation. The secretion level of IL-6 and IFN-β of the chicken infected by E.tenella with viruses are higher than the chicken infected by E.tenella without viruses. Infected with E.tenella with viruses cecum lesion were more serious such as edema, disintegration of intestinal epithelial cells rupture and intestinal mucosa damage fracture compared with infected with E.tenella without viruses. Preliminary infered that host resistance to infected with E.tenella with viruses and E.tenella without viruses may has different pathogenic mechanisms.