Oral and Parenteral Vaccination against Escherichia coli in Piglets Results in Different Responses

Abstract

The available E. coli vaccines involve two main types (inactivated and live non-pathogenic) and two routes of administration (oral and parenteral) but the mechanism by which both vaccines and routes of administration work is not yet fully elucidated. The influence of a parenteral vaccine (PV) and an oral one (OV) was studied by analyzing the gene expression of biomarkers indicating cellular infiltration (calprotectin, CAL), tight junction proteins (occludin OCL, and zonulin ZON) that maintain intestinal paracellular integration and two proinflammatory (IFN-γ) and anti-inflammatory (TGF-β) mediator cytokines, as well as histomorphology and IgA production cell density. Differences were observed in CAL, more infiltrated in orally vaccinated animals; OCL also increased in orally vaccinated animals, and higher density of IgA-producing cells in ileum for orally vaccinated groups. Cytokine expression is also different; and there is a lower mRNA for IFN-γ in the parenteral than in the oral vaccinated animals. Finally, the villus height-to-crypt depth ratio was higher in the orally vaccinated groups. The data collectively show clear and different effects derived from the use of each type of vaccine, route of administration and regimen. The results suggest a more rapid and direct effect of oral vaccination and a state of suppression in the absence of a second oral stimulus by the pathogen.

Is Oral Vaccination against Escherichia coli Influenced by Zinc Oxide?

“…Relative quantification of the gene expression of calprotectin, zonulin, occludin, claudin, IL1α, IL1β, IL6, IL8, IL10, IL12p35, IL12p40, IFNα, IFNγ, TGFβ, and TNFα was performed using the methodology and primers previously described [12,21,22], and using β-actin as a housekeeping gene (Table 2). All relative quantifications were carried out on faecal samples.…”

“…The preservative was recovered before RNA isolation, centrifuged at 3900× g for 10 min, and preserved at −80 • C until analysis. IgA quantification was performed as described in the literature [12,31] using the Pig IgA ELISA kit (Bethyl Laboratories, Montgomery, TX, USA) according to the manufacturer's specifications.…”

“…In fact, the use of zinc oxide at therapeutic levels was banned in the European Union (EU) in June 2022 [8]. Vaccination is another strategy that is currently being used, with both parenteral and oral vaccines available, both of which are effective [9][10][11] but produce different immune responses immediately after administration [12].…”

“…After oral vaccination with a bivalent F4/F18 vaccine, increased gene expression of cytokines such as IFNγ and TGFβ in the ileum, calprotectin in the jejunum and ileum, and occludin in the jejunum, ileum, and colon, as well as decreased mRNA for zonulin in the jejunum, ileum, and colon, have been observed [12].…”

Measurement of Calprotectin (S100A8/A9) in the Saliva of Pigs: Validation Data of A Commercially Available Automated Assay and Changes in Sepsis, Inflammation, and Stress

“…In pigs, CALP protein levels have been measured in faeces, increasing in animals with colitis [ 6 , 7 , 8 ]. In addition, variations in gene expression for calprotectin have also been found in the ileum after oral vaccination against E. coli [ 9 ]. However, to the authors’ knowledge, there are no reports about the measurement of CALP in saliva, despite the advantages that this sample type has.…”