Main content

Intestinal T Cell Responses Following Experimental Enteric Mycobacterium avium subspecies paratuberculosis (Map) Inoculation in Holstein Calves

Show full item record

Title: Intestinal T Cell Responses Following Experimental Enteric Mycobacterium avium subspecies paratuberculosis (Map) Inoculation in Holstein Calves
Author: Egan, Rebecca
Department: Department of Pathobiology
Program: Veterinary Science
Advisor: Plattner, Brandon
Abstract: Mycobacterium avium subspecies paratuberculosis (Map) is an obligate intracellular bacterium that causes Johne’s disease, which is a chronic, progressive and fatal disease of ruminant species. Transmission occurs via the fecal-oral route, and mostly during the perinatal period following ingestion of Map from the environment. Data suggest that only a small percentage of Map-exposed calves progress to clinical disease, and this may be due to differences in initial immune responses at the Map infection site following initial exposure. Little is known about early cellular immune responses, host-pathogen interactions and specific mechanisms of the anti-Map response in the ileum at the site of Map infection. Host responses at initial infection sites are hypothesized to play a significant role during Map infection, and possibly in resistance or resilience to infection and disease; therefore, the aim of this study was to characterize early cellular immune responses in the calf intestine following experimental intestinal Map infection. We used immunofluorescence microscopy to assess proportions of CD3+, γδ+, WC1+, and CD8α+ cells in the ileum after experimental Map inoculation, in addition to digital droplet PCR to measure IL-17, IFN-γ, and IL-10 mRNA gene expression in ileal tissue. We found that the proportion of CD3+ cells in the intestinal mucosa increased over time regardless of Map exposure. Further, WC1+ cells were significantly increased in the intestinal mucosa of Map-exposed calves, but not unexposed calves, suggesting these cells may be important during early host defense in the intestine. This study provides important insight into early local host immunity following enteric Map infection and contributes to understanding specific factors that contribute to immune defense in the intestine of calves.
URI: http://hdl.handle.net/10214/15028
Date: 2019-01


Files in this item

Files Size Format View
Egan_Rebecca_201901_DVSc.pdf 1.600Mb PDF View/Open

This item appears in the following Collection(s)

Show full item record