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Journal of veterinary internal medicine2019; 33(3); 1493-1499; doi: 10.1111/jvim.15511

In vitro evaluation of complement deposition and opsonophagocytic killing of Rhodococcus equi mediated by poly-N-acetyl glucosamine hyperimmune plasma compared to commercial plasma products.

Abstract: The bacterium Rhodococcus equi can cause severe pneumonia in foals. The absence of a licensed vaccine and limited effectiveness of commercial R. equi hyperimmune plasma (RE-HIP) create a great need for improved prevention of this disease. Objective: Plasma hyperimmune to the capsular polysaccharide poly-N-acetyl glucosamine (PNAG) would be significantly more effective than RE-HIP at mediating complement deposition and opsonophagocytic killing (OPK) of R. equi. Methods: Venipuncture was performed on 9 Quarter Horses. Methods: The ability of the following plasma sources to mediate complement component 1 (C1) deposition onto either PNAG or R. equi was determined by ELISA: (1) PNAG hyperimmune plasma (PNAG-HIP), (2) RE-HIP, and (3) standard non-hyperimmune commercial plasma (SP). For OPK, each plasma type was combined with R. equi, equine complement, and neutrophils isolated from horses (n = 9); after 4 hours, the number of R. equi in each well was determined by quantitative culture. Data were analyzed using linear mixed-effects regression with significance set at P < .05. Results: The PNAG-HIP and RE-HIP were able to deposit significantly (P < .05) more complement onto their respective targets than the other plasmas. The mean proportional survival of R. equi opsonized with PNAG-HIP was significantly (P < .05) less (14.7%) than that for SP (51.1%) or RE-HIP (42.2%). Conclusions: Plasma hyperimmune to PNAG is superior to RE-HIP for opsonizing and killing R. equi in vitro. Comparison of these 2 plasmas in field trials is warranted because of the reported incomplete effectiveness of RE-HIP.
© 2019 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.
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Publication Date: 2019-04-29 PubMed ID: 31034109PubMed Central: PMC6524092DOI: 10.1111/jvim.15511Google Scholar: Lookup
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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.

This study investigated the effectiveness of a plasma hyperimmune to a specific capsular polysaccharide, poly-N-acetyl glucosamine (PNAG), in comparison to commercially available plasma products for fighting off infection caused by Rhodococcus equi bacteria. The researchers found that the plasma enhanced with poly-N-acetyl glucosamine was more effective at combating the bacteria in the laboratory setup than were the commercial products on the market.

Research Methodology

  • The experiment involved nine Quarter Horses from which venipunctures were performed for sample collection.
  • The researchers then analyzed the abilities of plasma products from varied sources to mediate deposition of complement component 1 (C1) onto either the bacterium Rhodococcus equi or the polysaccharide PNAG.
  • The assessment was carried out through an Enzyme-Linked Immunosorbent Assay (ELISA).
  • Evaluation was done on three types of plasmas: (1) PNAG hyperimmune plasma (PNAG-HIP), (2) Rhodococcus equi hyperimmune plasma (RE-HIP), and (3) standard non-hyperimmune commercial plasma (SP).
  • An opsonophagocytic killing (OPK) test was also performed. In this test, each of the above plasma types were combined with Rhodococcus equi bacteria, equine complement, and neutrophils isolated from the horses.
  • After a period of four hours, the number of Rhodococcus equi present in each setup was determined using quantitative culture.
  • Data analysis was performed using linear mixed-effects regression, and significance was set at P < .05.

Key Findings

  • The PNAG-HIP and RE-HIP were found to have a significantly greater ability (P < .05) than the other plasmas in depositing more complement onto their respective targets.
  • In terms of survival of the Rhodococcus equi bacteria, the results showed that the mean proportional survival rates for the bacteria opsonized with PNAG-HIP was significantly lower (14.7%) compared to that opsonized with SP (51.1%) or RE-HIP (42.2%).

Conclusions

The researchers concluded that the plasma hyperimmune to PNAG outperforms RE-HIP in opsonizing and killing Rhodococcus equi in vitro. As a result, they recommended a comparison of these two plasmas in field trials, given the reported incomplete effectiveness of RE-HIP. This research makes a significant contribution to the development of plasma products intended for addressing Rhodococcus equi infection.

Cite This Article

APA
Folmar CN, Cywes-Bentley C, Bordin AI, Rocha JN, Bray JM, Kahn SK, Schuckert AE, Pier GB, Cohen ND. (2019). In vitro evaluation of complement deposition and opsonophagocytic killing of Rhodococcus equi mediated by poly-N-acetyl glucosamine hyperimmune plasma compared to commercial plasma products. J Vet Intern Med, 33(3), 1493-1499. https://doi.org/10.1111/jvim.15511

Publication

Journal of veterinary internal medicine
ISSN: 1939-1676
NlmUniqueID: 8708660
Country: United States
Language: English
Volume: 33
Issue: 3
Pages: 1493-1499

Researcher Affiliations

Folmar, Chelsea N
  • Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas.
Cywes-Bentley, Colette
  • Department of Medicine, Harvard Medical School, Harvard University, Boston, Massachusetts.
Bordin, Angela I
  • Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas.
Rocha, Joana N
  • Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas.
Bray, Jocelyne M
  • Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas.
Kahn, Susanne K
  • Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas.
Schuckert, Amanda E
  • Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas.
Pier, Gerald B
  • Department of Medicine, Harvard Medical School, Harvard University, Boston, Massachusetts.
Cohen, Noah D
  • Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas.

MeSH Terms

  • Acetylglucosamine / immunology
  • Actinomycetales Infections / immunology
  • Actinomycetales Infections / veterinary
  • Animals
  • Antibodies, Bacterial / blood
  • Complement C1 / immunology
  • Female
  • Horse Diseases / immunology
  • Horse Diseases / microbiology
  • Horses / immunology
  • Male
  • Neutrophils
  • Plasma / immunology
  • Rhodococcus equi / immunology

Grant Funding

  • ALOPEXX Enterprises, Ltd. (Unrestricted Gift)
  • Chelsea Folmar was supported by the Boehringer-Ing / Boehringer-Ingelheim Animal Health
  • Link Equine Research Endowment, Texas A&M University
  • 5T32OD011083-08 / Office of Extramural Research, National Institutes of Health

Conflict of Interest Statement

Gerald B. Pier is an inventor of intellectual properties (human monoclonal antibody to PNAG and PNAG vaccines) that are licensed by Brigham and Women's Hospital to Alopexx Vaccine, LLC, and Alopexx Pharmaceuticals, LLC, entities in which Gerald B. Pier also holds equity. As an inventor of intellectual properties, Gerald B. Pier also has the right to receive a share of licensing‐related income (royalties, fees) through Brigham and Women's Hospital from Alopexx Pharmaceuticals, LLC, and Alopexx Vaccine, LLC. Gerald B. Pier's interests were reviewed and are managed by the Brigham and Women's Hospital and Partners Healthcare in accordance with their conflict of interest policies. Colette Cywes‐Bentley is an inventor of intellectual properties (use of human monoclonal antibody to PNAG and use of PNAG vaccines) that are licensed by Brigham and Women's Hospital to Alopexx Pharmaceuticals, LLC. As an inventor of intellectual properties, Colette Cywes‐Bentley also has the right to receive a share of licensing‐related income (royalties, fees) through Brigham and Women's Hospital from Alopexx Pharmaceuticals, LLC. Noah D. Cohen has received an unrestricted gift to the Equine Infectious Disease Laboratory at Texas A&M University to support research from Alopexx Vaccines, LLC.

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Citations

This article has been cited 9 times.
  1. Rivolta AA, Bujold AR, Wilmarth PA, Phinney BS, Navelski JP, Horohov DW, Sanz MG. Comparison of the broncoalveolar lavage fluid proteomics between foals and adult horses. PLoS One 2023;18(9):e0290778.
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  2. Kahn SK, Cywes-Bentley C, Blodgett GP, Canaday NM, Turner-Garcia CE, Flores-Ahlschwede P, Metcalfe LL, Nevill M, Vinacur M, Sutter PJ, Meyer SC, Bordin AI, Pier GB, Cohen ND. Randomized, controlled trial comparing Rhodococcus equi and poly-N-acetyl glucosamine hyperimmune plasma to prevent R equi pneumonia in foals. J Vet Intern Med 2021 Nov;35(6):2912-2919.
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