5 research outputs found
First report of bovine anaplasmosis by Anaplasma centrale in Europe, molecular identification and phylogenetic analysis
Ileal and jejunal Peyerâs patches play distinct roles in mucosal immunity of sheep
The majority of pathogens enter the body through mucosal surfaces and it is now evident that mucosal immunity can provide effective disease protection. However, the induction of mucosal immunity will require efficient targeting of mucosal vaccines to appropriate mucosa-associated lymphoid tissue. An animal model, based upon the surgical preparation of sterile intestinal âloopsâ (blind-ended segments of intestine), was developed to evaluate mucosal and systemic immune responses to enteric vaccines in ruminants. The effectiveness of end-to-end intestinal anastomoses was evaluated and fetal surgery did not disrupt normal intestinal function in lambs up to 6â7 months after birth. The immunological competence of Peyerâs patches (PP) within the intestinal âloopsâ was evaluated with a human adenovirus 5 vector expressing the gD gene of bovine herpesvirus-1. This vaccine vector induced both mucosal and systemic immune responses when injected into intestinal âloopsâ of 5â6-week-old lambs. Antibodies to the gD protein were detected in the lumen of intestinal âloopsâ and serum and PP lymphocytes proliferated in response to gD protein. The immune competence of ileal and jejunal PP was compared and these analyses confirmed that jejunal PP are an efficient site for the induction of mucosal immune responses. This was confirmed by the presence of gD-specific antibody-secreting cells in jejunal but not ileal PP. Systemic but not mucosal immune responses were detected when the vaccine vector was delivered to the ileal PP. In conclusion, this model provided an effective means to evaluate the immunogenicity of potential oral vaccines and to assess the immunological competence of ileal and jejunal Peyerâs patches