Immunization but not natural infection of horses results in antibody activity against the S protein of Streptococcus equi subsp equi.
Abstract: Evaluate the immunogenicity of a vaccine targeting the S protein (Ssee) of Streptococcus equi subsp equi and determine antibody activity against Ssee in horses with strangles. Methods: The study was designed as a prospective experiment using 20 university-owned Quarter Horses and a cross-sectional serosurvey of 78 privately owned horses with strangles. Horses were immunized IM with 0 (n = 4), 200 (n = 8), or 400 (n = 8) μg of recombinant Ssee at weeks 0, 4, and 12. Serum and nasal secretions were collected at weeks 0, 4, 6, 12, 16, and 28 and tested by ELISA for immunoglobulin (Ig)-G against Ssee; nasal secretions were also tested for anti-Ssee IgA. The function of anti-Ssee IgG in serum was tested for complement deposition onto Ssee and opsonophagocytic killing of S equi subsp equi. Serum from horses with strangles was tested by ELISA for anti-Ssee IgG activity. Results: Immunization with Ssee significantly (P < .05) increased serum and nasal IgG (but not nasal IgA) against Ssee for up to 12 weeks after the third immunization, and serum from vaccinated horses mediated significantly (P .05), than controls. Horses with strangles did not develop high levels of serum IgG activity against Ssee. Conclusions: Immunizing horses with Ssee resulted in increased activity of functional IgG in serum and nasal secretions, and horses with strangles had very low levels of serum IgG activity against Ssee. Conclusions: S protein has potential as a vaccine to reduce the severity of strangles and differentiate between infected and vaccinated horses.
Publication Date: 2024-12-16 PubMed ID: 39681079DOI: 10.2460/ajvr.24.08.0228Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research investigates the effectiveness of a vaccine for strangles, a horse disease caused by the bacteria Streptococcus equi subsp equi, specifically targeting the bacteria’s S protein. The vaccine was shown to generate an immune response against the bacteria in immunized horses but not in naturally infected horses.
Study Design and Methods
- This study was a combination of a prospective experiment and a cross-sectional serosurvey. A total of 20 university-owned Quarter Horses were selected for the experiment and 78 privately owned, strangles-infected horses were examined in the cross-sectional study.
- For the experiment, 20 horses were divided into three groups, receiving doses of 0 (n = 4, serving as the control group), 200 (n = 8), or 400 (n = 8) micrograms of recreated Ssee protein (the target of the vaccine). The vaccine was administered at weeks 0, 4, and 12.
- Throughout the experiment, researchers collected both serum and nasal secretion samples from the horses at predefined intervals (weeks 0, 4, 6, 12, 16, and 28) for testing purposes. The tests were designed to detect the presence of immunoglobulin (Ig)-G against the Ssee protein; nasal secretions were also tested for IgA.
Findings and Interpretations
- The results demonstrated that immunizing horses with Ssee significantly increased nasal and serum antibody activity (IgG, but not IgA) against the Ssee protein for up to 12 weeks following the final immunization.
- The functional activity of the antibodies was also tested. Vaccinated horse serum demonstrated increased complement deposition onto the Ssee protein, though it did not improve opsonophagocytic killing (the immune process where cells known as phagocytes engulf and destroy foreign bodies or pathogens).
- In contrast, horses naturally infected with strangles did not show a strong antibody response to the Ssee protein, indicating it’s not a natural target for the immune system during the infection.
- This difference in immune response allowed researchers to distinguish between naturally infected and vaccinated horses based on their antibody activity against the Ssee protein.
Conclusions
- The research concludes that the Ssee protein offers potential as a vaccine target to prevent strangles in horses. Immunizing horses with the Ssee protein led to increased functional antibody activity in these animals.
- This research also suggests that strangles-infected horses exhibit very low levels of antibody activity against the Ssee protein, contrasting with vaccinated horses, and this could potentially help differentiate between infected and vaccinated horses.
Cite This Article
APA
Cohen ND, Hughes EV, Bayne C, Morris ERA, Bray JM, Landrock KK, Gonzales DM, Baker RM, Klein RL, Liu W, Legere RM, Wehmeyer SG, Bordin AI, Wierzbicki IH, Gonzalez DJ.
(2024).
Immunization but not natural infection of horses results in antibody activity against the S protein of Streptococcus equi subsp equi.
Am J Vet Res, 1-11.
https://doi.org/10.2460/ajvr.24.08.0228 Publication
Researcher Affiliations
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Department of Pharmacology, School of Medicine, University of California-San Diego, La Jolla, CA.
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California-San Diego, La Jolla, CA.
- Center for Microbiome Innovation, Jacobs School of Engineering, University of California-San Diego, La Jolla, CA.
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University, Houston, TX.
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Department of Pharmacology, School of Medicine, University of California-San Diego, La Jolla, CA.
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California-San Diego, La Jolla, CA.
- Center for Microbiome Innovation, Jacobs School of Engineering, University of California-San Diego, La Jolla, CA.
- Department of Pharmacology, School of Medicine, University of California-San Diego, La Jolla, CA.
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California-San Diego, La Jolla, CA.
- Center for Microbiome Innovation, Jacobs School of Engineering, University of California-San Diego, La Jolla, CA.
Citations
This article has been cited 0 times.Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
