Effects of aroA deleted E. coli vaccine on intestinal microbiota and mucosal immunity

• Published in: Comparative immunology, microbiology and infectious diseases Vol. 75; p. 101612
• Main Authors: Beirão, Breno C.B., Ingberman, Max, Mesa, Dany, Salles, Gleidson B.C., Muniz, Eduardo C., Caron, Luiz Felipe
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2021; Elsevier Science Ltd
• Subjects: Antimicrobial agents; Cell activation; E coli; Gut-associated lymphoid tissues; IgA; Immunity; Immunization; Immunoglobulin A; Interleukin 6; Intestinal microflora; Intestine; Lymphocytes; Lymphocytes T; Lymphoid tissue; Microbiota; mRNA; Mucosal; Mucosal immunity; Spleen; Spray; Vaccination; Vaccine; Vaccines; TCR; IgA; Microbiota; D; Mucosal; E.coli; Vaccine; Spray; OUT
• ISSN: 0147-9571; 1878-1667
• DOI: 10.1016/j.cimid.2021.101612

•Mucosal E. coli vaccination changed the cecal microbiota.•However, specific lymphocyte proliferation was not altered in ceca.•Accordingly, vaccination induced IgA only in respiratory mucosae. E. coli infection of broilers can result in systemic diseases and productivity losses. Use of antimicrobials against this condition is common but other approaches, such as vaccination, are gaining ground. Anecdotal field reports indicate that intestinal health is improved unspecifically following E. coli live vaccination. We hypothesized that the intestine may be an important site for the functionality of the vaccine. Vaccine effects on the intestine were assessed. Spray vaccination induced marked alterations of the caecum microbiota of broilers within 3 days, and this effect gradually waned. However, T cell activation occurred in the spleen, but not in caecal tonsils, and anti-E. coli IgA was concentrated in the respiratory mucosae. Accordingly, IL-6 mRNA was produced in the lungs following immunization. Overall, these data are an initial indication that any vaccine-induced effects on the intestine are greatly associated with the microbiota. However, immunity conferred by vaccination is not primarily induced in gut-associated lymphoid tissues.