Previously, we have shown that CD18, the beta-subunit of beta(2)-integrins, serves as a receptor for leukotoxin (Lkt) secreted by Mannheimia (Pasteurella) haemolytica on bovine leukocytes. Anti-CD18 monoclonal antibodies (mAbs) inhibit Lkt-induced cytolysis of bighorn sheep (Ovis canadensis) leukocytes suggesting that CD18 may serve as a receptor for Lkt on the leukocytes of this species as well. Confirmation of bighorn sheep CD18 as a receptor for Lkt, and elucidation of the enhanced Lkt-susceptibility of bighorn sheep polymorphonuclear leukocytes (PMNs), necessitates the cloning and sequencing of cDNA encoding bighorn sheep CD18. Hence, in this study we cloned and sequenced the cDNA encoding CD18 of bighorn sheep, and compared with that of other animal species. The cDNA of bighorn sheep CD18 has an open reading frame (ORF) of 2310bp. CD18 sequences obtained individually from peripheral blood mononuclear cells (PBMCs) and PMNs were identical to each other. Comparison of the deduced 770-amino acid sequence of CD18 of bighorn sheep with that of domestic sheep, goats, cattle, humans and mice revealed 99, 98, 95, 82 and 80% identity, respectively. Availability of cloned bighorn sheep CD18 cDNA should allow the molecular characterization of M. haemolytica Lkt-receptor interactions in bighorn sheep and other ruminants that are susceptible to this disease.
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http://dx.doi.org/10.1016/j.vetimm.2005.08.030 | DOI Listing |
J Clin Microbiol
January 2025
Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, USA.
We hypothesized that bighorn sheep ewes with chronic nasal carriage are the source of infection that results in fatal lamb pneumonia. We tested this hypothesis in captive bighorn ewes at two study facilities over a 5-year period, by identifying carrier ewes and then comparing lamb fates in groups that did (exposed pens) or did not (non-exposed pens) include one or more carrier ewes. Most (23 of 30) lambs born in exposed pens, but none of 11 lambs born in non-exposed pens, contracted fatal pneumonia.
View Article and Find Full Text PDFMicroorganisms
December 2024
Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA.
Bighorn sheep (BHS) populations have been reported to experience high levels of morbidity and mortality following infection with . This contrasts with the subclinical presentation in domestic sheep (DS). Understanding this difference requires baseline knowledge of pre- and post-infection immune responses of both species.
View Article and Find Full Text PDFSci Rep
December 2024
United States Fish and Wildlife Service, Tulsa, OK, USA.
Abundance estimates inform ungulate management and recovery efforts. Yet effective and affordable estimation techniques remain absent for most ungulates lacking identifiable marks and inhabiting rugged or highly vegetated terrain. Methods using N-mixture models with camera trap imagery form an appealing solution but remain unvalidated.
View Article and Find Full Text PDFAbstractDensity dependence is often assumed in population dynamics, but its importance in small, isolated populations has been questioned. We evaluated the relative influence of density dependence, environmental conditions, and sporadic events (disease outbreaks and specialist predators) on annual population growth rate, annual female reproduction, and annual survival of juveniles and adult females in three populations of mountain ungulates. We analyzed long-term (30-47 years) individual-based data on two bighorn sheep populations and one mountain goat population in Alberta, Canada.
View Article and Find Full Text PDFJ Wildl Dis
November 2024
Southeastern Cooperative Wildlife Disease Study, 589 D. W. Brooks Dr., Athens, Georgia 30602, USA.
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