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Liu L, Cai P, Gu W, Duan X, Gao S, Ma X, Ma Y, Ma S, Li G, Wang X, Cai K, Wang Y, Cai T, Zhao H. Evaluation of vaccine candidates against Rhodococcus equi in BALB/c mice infection model: cellular and humoral immune responses. BMC Microbiol 2024; 24:249. [PMID: 38977999 PMCID: PMC11229254 DOI: 10.1186/s12866-024-03408-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 07/02/2024] [Indexed: 07/10/2024] Open
Abstract
Rhodococcus equi (R. equi) is a zoonotic opportunistic pathogen that mainly causes fatal lung and extrapulmonary abscesses in foals and immunocompromised individuals. To date, no commercial vaccine against R. equi exists. We previously screened all potential vaccine candidates from the complete genome of R. equi using a reverse vaccinology approach. Five of these candidates, namely ABC transporter substrate-binding protein (ABC transporter), penicillin-binding protein 2 (PBD2), NlpC/P60 family protein (NlpC/P60), esterase family protein (Esterase), and M23 family metallopeptidase (M23) were selected for the evaluation of immunogenicity and immunoprotective effects in BALB/c mice model challenged with R. equi. The results showed that all five vaccine candidate-immunized mice experienced a significant increase in spleen antigen-specific IFN-γ- and TNF-α-positive CD4 + and CD8 + T lymphocytes and generated robust Th1- and Th2-type immune responses and antibody responses. Two weeks after the R. equi challenge, immunization with the five vaccine candidates reduced the bacterial load in the lungs and improved the pathological damage to the lungs and livers compared with those in the control group. NlpC/P60, Esterase, and M23 were more effective than the ABC transporter and PBD2 in inducing protective immunity against R. equi challenge in mice. In addition, these vaccine candidates have the potential to induce T lymphocyte memory immune responses in mice. In summary, these antigens are effective candidates for the development of protective vaccines against R. equi. The R. equi antigen library has been expanded and provides new ideas for the development of multivalent vaccines.
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Affiliation(s)
- Lu Liu
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
- Xinjiang Key Laboratory of New Drug Study and Creation for Herbivorous Animal, Urumqi, China
| | - Peng Cai
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Weifang Gu
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Xingxun Duan
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Shiwen Gao
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Xuelian Ma
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
- Xinjiang Key Laboratory of New Drug Study and Creation for Herbivorous Animal, Urumqi, China
| | - Yuhui Ma
- Zhaosu Xiyu Horse Industry Co., Ltd., Yining, China
| | - Siyuan Ma
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Guoqing Li
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Xiangyu Wang
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Kuojun Cai
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Yanfeng Wang
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Tao Cai
- Xinjiang Agricultural Vocational Technical College, Changji, China
| | - Hongqiong Zhao
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China.
- Xinjiang Key Laboratory of New Drug Study and Creation for Herbivorous Animal, Urumqi, China.
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da Silveira BP, Barhoumi R, Bray JM, Cole-Pfeiffer HM, Mabry CJ, Burghardt RC, Cohen ND, Bordin AI. Impact of surface receptors TLR2, CR3, and FcγRIII on Rhodococcus equi phagocytosis and intracellular survival in macrophages. Infect Immun 2024; 92:e0038323. [PMID: 38018994 PMCID: PMC10790823 DOI: 10.1128/iai.00383-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 10/26/2023] [Indexed: 11/30/2023] Open
Abstract
The virulence-associated protein A (VapA) produced by virulent Rhodococcus equi allows it to replicate in macrophages and cause pneumonia in foals. It is unknown how VapA interacts with mammalian cell receptors, but intracellular replication of avirulent R. equi lacking vapA can be restored by supplementation with recombinant VapA (rVapA). Our objectives were to determine whether the absence of the surface receptors Toll-like receptor 2 (TLR2), complement receptor 3 (CR3), or Fc gamma receptor III (FcγRIII) impacts R. equi phagocytosis and intracellular replication in macrophages, and whether rVapA restoration of virulence in R. equi is dependent upon these receptors. Wild-type (WT) murine macrophages with TLR2, CR3, or FcγRIII blocked or knocked out (KO) were infected with virulent or avirulent R. equi, with or without rVapA supplementation. Quantitative bacterial culture and immunofluorescence imaging were performed. Phagocytosis of R. equi was not affected by blockade or KO of TLR2 or CR3. Intracellular replication of virulent R. equi was not affected by TLR2, CR3, or FcγRIII blockade or KO; however, avirulent R. equi replicated in TLR2-/- and CR3-/- macrophages but not in WT and FcγRIII-/-. rVapA supplementation did not affect avirulent R. equi phagocytosis but promoted intracellular replication in WT and all KO cells. By demonstrating that TLR2 and CR3 limit replication of avirulent but not virulent R. equi and that VapA-mediated virulence is independent of TLR2, CR3, or FcγRIII, our study provides novel insights into the role of these specific surface receptors in determining the entry and intracellular fate of R. equi.
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Affiliation(s)
- Bibiana Petri da Silveira
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Rola Barhoumi
- Department of Veterinary Integrative Biosciences, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Jocelyne M. Bray
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Hannah M. Cole-Pfeiffer
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Cory J. Mabry
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Robert C. Burghardt
- Department of Veterinary Integrative Biosciences, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Noah D. Cohen
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
| | - Angela I. Bordin
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, Texas A&M University, School of Veterinary Medicine & Biomedical Sciences, College Station, Texas, USA
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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:e0290778. [PMID: 37669266 PMCID: PMC10479908 DOI: 10.1371/journal.pone.0290778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 08/15/2023] [Indexed: 09/07/2023] Open
Abstract
Neonates have different cellular composition in their bronchoalveolar lavage fluid (BALF) when compared to foals and adult horses; however, little is known about the non-cellular components of BALF. The objective of this study was to determine the proteomic composition of BALF in neonatal horses and to compare it to that of foals and adult horses. Bronchoalveolar lavage fluid samples of seven neonates (< 1 week age), four 5 to 7-week-old foals, and six adult horses were collected. Quantitative proteomics of the fluid was performed using tandem mass tag labeling followed by high resolution liquid chromatography tandem mass spectrometry and protein relative abundances were compared between groups using exact text. A total of 704 proteins were identified with gene ontology terms and were classified. Of these, 332 proteins were related to the immune system in neonates, foals, and adult horses. The most frequent molecular functions identified were binding and catalytic activity and the most common biological processes were cellular process, metabolic process, and biological regulation. There was a significant difference in the proteome of neonates when compared to foals and to adult horses. Neonates had less relative expression (FDR < 0.01) of many immune-related proteins, including immunoglobulins, proteins involved in the complement cascade, ferritin, BPI fold-containing family B member 1, and macrophage receptor MARCO. This is the first report of equine neonate BALF proteomics and reveals differential abundance of proteins when compared to BALF from adult horses. The lower relative abundance of immune-related proteins in neonates could contribute to their susceptibility to pulmonary infections.
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Affiliation(s)
- Alejandra A. Rivolta
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, United States of America
| | - Adina R. Bujold
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, United States of America
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
| | - Phillip A. Wilmarth
- Proteomic Shared Resource, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Brett S. Phinney
- Genome Center Proteomics Core Facility, UC Davis, Davis, California, United States of America
| | - Joseph P. Navelski
- School of Economic Sciences, Washington State University, Pullman, Washington, United States of America
| | - David W. Horohov
- Gluck Equine Research Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - Macarena G. Sanz
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, United States of America
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Kahn SK, Cohen ND, Bordin AI, Coleman MC, Heird JC, Welsh TH. Transfusion of hyperimmune plasma for protecting foals against Rhodococcus equi pneumonia. Equine Vet J 2022; 55:376-388. [PMID: 35834170 DOI: 10.1111/evj.13858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 07/08/2022] [Indexed: 11/03/2022]
Abstract
The bacterium Rhodococcus equi causes pneumonia in foals that is prevalent at breeding farms worldwide. In the absence of an effective vaccine, transfusion of commercial plasma from donor horses hyperimmunised against R. equi is used by many farms to reduce the incidence of pneumonia among foals at farms where the disease is endemic. The effectiveness of hyperimmune plasma for controlling R. equi pneumonia in foals has varied considerably among reports. The purposes of this narrative review are: 1) to review early studies that provided a foundational basis for the practice of transfusion of hyperimmune plasma that is widespread in the US and in many other countries; 2) to summarise current knowledge of hyperimmune plasma for preventing R. equi pneumonia; 3) to provide an interpretive summary of probable explanations for the variable results among studies evaluating the effectiveness of transfusion of hyperimmune plasma for reducing the incidence of R. equi pneumonia; 4) to review mechanisms by which hyperimmune plasma might mediate protection; and 5) to consider risks of transfusing foals with hyperimmune plasma. Although the weight of evidence supports the practice of transfusing foals with hyperimmune plasma to prevent R. equi pneumonia, many important gaps in our knowledge of this topic remain including the volume/dose of hyperimmune plasma to be transfused, the timing(s) of transfusion, and the mechanism(s) by which hyperimmune plasma mediates protection. Transfusing foals with hyperimmune plasma is expensive, labour-intensive, and carries risks for foals; therefore, alternative approaches for passive and active immunisation to prevent R. equi pneumonia are greatly needed. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Susanne K Kahn
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Noah D Cohen
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Angela I Bordin
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Michelle C Coleman
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - James C Heird
- Department of Animal Science, College of Agriculture & Life Sciences, Texas A&M University, College Station, TX, USA
| | - Thomas H Welsh
- Department of Animal Science, College of Agriculture & Life Sciences, Texas A&M University, College Station, TX, USA
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5
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Bordin AI, Huber L, Sanz M, Cohen N. Rhodococcus equi Foal Pneumonia: Update on Epidemiology, Immunity, Treatment, and Prevention. Equine Vet J 2022; 54:481-494. [PMID: 35188690 DOI: 10.1111/evj.13567] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/03/2022] [Accepted: 02/17/2022] [Indexed: 11/25/2022]
Abstract
Pneumonia in foals caused by the bacterium Rhodococcus equi has a worldwide distribution and is a common cause of disease and death for foals. The purpose of this narrative review is to summarise recent developments pertaining to the epidemiology, immune responses, treatment, and prevention of rhodococcal pneumonia of foals. Screening tests have been used to implement earlier detection and treatment of foals with presumed subclinical R. equi pneumonia to reduce mortality and severity of disease. Unfortunately, this practice has been linked to the emergence of antimicrobial resistant R. equi in North America. Correlates of protective immunity for R. equi infections of foals remain elusive, but recent evidence indicates that innate immune responses are important both for mediating killing and orchestrating adaptive immune responses. A macrolide antimicrobial in combination with rifampin remains the recommended treatment for foals with R. equi pneumonia. Great need exists to identify which antimicrobial combination is most effective for treating foals with R. equi pneumonia and to limit emergence of antimicrobial-resistant strains. In the absence of an effective vaccine against R. equi, passive immunisation remains the only commercially-available method for effectively reducing the incidence of R. equi pneumonia. Because passive immunisation is expensive, labour-intensive, and carries risks for foals, great need exists to develop alternative approaches for passive and active immunisation.
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Affiliation(s)
- Angela I Bordin
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, 77843-4475, USA
| | - Laura Huber
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, 36849, USA
| | - Macarena Sanz
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, 99164-6610, USA
| | - Noah Cohen
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, 77843-4475, USA
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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; 35:2912-2919. [PMID: 34738651 PMCID: PMC8692225 DOI: 10.1111/jvim.16294] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 01/16/2023] Open
Abstract
Background Hyperimmune plasma raised against β‐1→6‐poly‐N‐acetyl glucosamine (PNAG HIP) mediates more opsonophagocytic killing of Rhodococcus equi (R equi) than does R equi hyperimmune plasma (RE HIP) in vitro. The relative efficacy of PNAG HIP and RE HIP to protect foals against R equi pneumonia, however, has not been evaluated. Hypothesis Transfusion with PNAG HIP will be superior to RE HIP in foals for protection against R equi pneumonia in a randomized, controlled, blinded clinical trial. Animals Four hundred sixty Quarter Horse and Thoroughbred foals at 5 large breeding farms in the United States. Methods A randomized, controlled, blinded clinical trial was conducted in which foals were transfused within 24 hours after birth with 2 L of either RE HIP or PNAG HIP. Study foals were monitored through weaning for clinical signs of pneumonia by farm veterinarians. The primary outcome was the proportion of foals that developed pneumonia after receiving each type of plasma. Results The proportion of foals that developed pneumonia was the same between foals transfused with RE HIP (14%; 32/228) and PNAG HIP (14%; 30/215). Conclusions and Clinical Importance Results indicate that PNAG HIP was not superior to a commercially available, United States Department of Agriculture‐licensed RE HIP product for protecting foals against R equi pneumonia under field conditions.
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Affiliation(s)
- Susanne K Kahn
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Colette Cywes-Bentley
- Department of Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | | | | | | | | | | | | | - Mariana Vinacur
- Department of Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | | | | | - Angela I Bordin
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Gerald B Pier
- Department of Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Noah D Cohen
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
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Cohen ND, Kahn SK, Cywes-Bentley C, Ramirez-Cortez S, Schuckert AE, Vinacur M, Bordin AI, Pier GB. Serum Antibody Activity against Poly- N-Acetyl Glucosamine (PNAG), but Not PNAG Vaccination Status, Is Associated with Protecting Newborn Foals against Intrabronchial Infection with Rhodococcus equi. Microbiol Spectr 2021; 9:e0063821. [PMID: 34319137 PMCID: PMC8552712 DOI: 10.1128/spectrum.00638-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 07/07/2021] [Indexed: 12/22/2022] Open
Abstract
Rhodococcus equi is a prevalent cause of pneumonia in foals worldwide. Our laboratory has demonstrated that vaccination against the surface polysaccharide β-1→6-poly-N-acetylglucosamine (PNAG) protects foals against intrabronchial infection with R. equi when challenged at age 28 days. However, it is important that the efficacy of this vaccine be evaluated in foals when they are infected at an earlier age, because foals are naturally exposed to virulent R. equi in their environment from birth and because susceptibility is inversely related to age in foals. Using a randomized, blind experimental design, we evaluated whether maternal vaccination against PNAG protected foals against intrabronchial infection with R. equi 6 days after birth. Vaccination of mares per se did not significantly reduce the incidence of pneumonia in foals; however, activities of antibody against PNAG or for deposition of complement component 1q onto PNAG was significantly (P < 0.05) higher among foals that did not develop pneumonia than among foals that developed pneumonia. Results differed between years, with evidence of protection during 2018 but not 2020. In the absence of a licensed vaccine, further evaluation of the PNAG vaccine is warranted, including efforts to optimize the formulation and dose of this vaccine. IMPORTANCE Pneumonia caused by R. equi is an important cause of disease and death in foals worldwide for which a licensed vaccine is lacking. Foals are exposed to R. equi in their environment from birth, and they appear to be infected soon after parturition at an age when innate and adaptive immune responses are diminished. Results of this study indicate that higher activity of antibodies recognizing PNAG was associated with protection against R. equi pneumonia, indicating the need for further optimization of maternal vaccination against PNAG to protect foals against R. equi pneumonia.
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Affiliation(s)
- Noah D. Cohen
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Susanne K. Kahn
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Colette Cywes-Bentley
- Department of Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Sophia Ramirez-Cortez
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Amanda E. Schuckert
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Mariana Vinacur
- Department of Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Angela I. Bordin
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Gerald B. Pier
- Department of Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Kahn SK, Cywes-Bentley C, Blodgett GP, Canaday NM, Turner-Garcia CE, Vinacur M, Cortez-Ramirez SC, Sutter PJ, Meyer SC, Bordin AI, Vlock DR, Pier GB, Cohen ND. Antibody activities in hyperimmune plasma against the Rhodococcus equi virulence -associated protein A or poly-N-acetyl glucosamine are associated with protection of foals against rhodococcal pneumonia. PLoS One 2021; 16:e0250133. [PMID: 34437551 PMCID: PMC8389416 DOI: 10.1371/journal.pone.0250133] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 06/25/2021] [Indexed: 11/18/2022] Open
Abstract
The efficacy of transfusion with hyperimmune plasma (HIP) for preventing pneumonia caused by Rhodococcus equi remains ill-defined. Quarter Horse foals at 2 large breeding farms were randomly assigned to be transfused with 2 L of HIP from adult donors hyperimmunized either with R. equi (RE HIP) or a conjugate vaccine eliciting antibody to the surface polysaccharide β-1→6-poly-N-acetyl glucosamine (PNAG HIP) within 24 hours of birth. Antibody activities against PNAG and the rhodococcal virulence-associated protein A (VapA), and to deposition of complement component 1q (C՛1q) onto PNAG were determined by ELISA, and then associated with either clinical pneumonia at Farm A (n = 119) or subclinical pneumonia at Farm B (n = 114). Data were analyzed using multivariable logistic regression. Among RE HIP-transfused foals, the odds of pneumonia were approximately 6-fold higher (P = 0.0005) among foals with VapA antibody activity ≤ the population median. Among PNAG HIP-transfused foals, the odds of pneumonia were approximately 3-fold (P = 0.0347) and 11-fold (P = 0.0034) higher for foals with antibody activities ≤ the population median for PNAG or C՛1q deposition, respectively. Results indicated that levels of activity of antibodies against R. equi antigens are correlates of protection against both subclinical and clinical R. equi pneumonia in field settings. Among PNAG HIP-transfused foals, activity of antibodies with C՛1q deposition (an indicator of functional antibodies) were a stronger predictor of protection than was PNAG antibody activity alone. Collectively, these findings suggest that the amount and activity of antibodies in HIP (i.e., plasma volume and/or antibody activity) is positively associated with protection against R. equi pneumonia in foals.
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MESH Headings
- Acetylglucosamine/immunology
- Actinomycetales Infections/immunology
- Actinomycetales Infections/microbiology
- Actinomycetales Infections/prevention & control
- Actinomycetales Infections/veterinary
- Animals
- Animals, Newborn/immunology
- Animals, Newborn/microbiology
- Antibodies, Bacterial/immunology
- Antibodies, Bacterial/therapeutic use
- Bacterial Proteins/immunology
- Female
- Horse Diseases/immunology
- Horse Diseases/microbiology
- Horse Diseases/prevention & control
- Horses/immunology
- Horses/microbiology
- Immunization, Passive/methods
- Immunization, Passive/veterinary
- Male
- Pneumonia, Bacterial/immunology
- Pneumonia, Bacterial/microbiology
- Pneumonia, Bacterial/prevention & control
- Pneumonia, Bacterial/veterinary
- Rhodococcus equi/immunology
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Affiliation(s)
- Susanne K. Kahn
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, United States of America
| | - Colette Cywes-Bentley
- Department of Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA, United States of America
| | | | | | | | - Mariana Vinacur
- Department of Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Sophia C. Cortez-Ramirez
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, United States of America
| | | | | | - Angela I. Bordin
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, United States of America
| | | | - Gerald B. Pier
- Department of Medicine, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Noah D. Cohen
- Department of Large Animal Clinical Sciences, Equine Infectious Disease Laboratory, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, United States of America
- * E-mail:
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Host-directed therapy in foals can enhance functional innate immunity and reduce severity of Rhodococcus equi pneumonia. Sci Rep 2021; 11:2483. [PMID: 33510265 PMCID: PMC7844249 DOI: 10.1038/s41598-021-82049-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 01/13/2021] [Indexed: 11/08/2022] Open
Abstract
Pneumonia caused by the intracellular bacterium Rhodococcus equi is an important cause of disease and death in immunocompromised hosts, especially foals. Antibiotics are the standard of care for treating R. equi pneumonia in foals, and adjunctive therapies are needed. We tested whether nebulization with TLR agonists (PUL-042) in foals would improve innate immunity and reduce the severity and duration of pneumonia following R. equi infection. Neonatal foals (n = 48) were nebulized with either PUL-042 or vehicle, and their lung cells infected ex vivo. PUL-042 increased inflammatory cytokines in BAL fluid and alveolar macrophages after ex vivo infection with R. equi. Then, the in vivo effects of PUL-042 on clinical signs of pneumonia were examined in 22 additional foals after intrabronchial challenge with R. equi. Foals infected and nebulized with PUL-042 or vehicle alone had a shorter duration of clinical signs of pneumonia and smaller pulmonary lesions when compared to non-nebulized foals. Our results demonstrate that host-directed therapy can enhance neonatal immune responses against respiratory pathogens and reduce the duration and severity of R. equi pneumonia.
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10
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Harvey AB, Bordin AI, Rocha JN, Bray JM, Cohen ND. Opsonization but not pretreatment of equine macrophages with hyperimmune plasma nonspecifically enhances phagocytosis and intracellular killing of Rhodococcus equi. J Vet Intern Med 2020; 35:590-596. [PMID: 33326149 PMCID: PMC7848299 DOI: 10.1111/jvim.16002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/25/2020] [Accepted: 12/02/2020] [Indexed: 11/26/2022] Open
Abstract
Background Evidence regarding the efficacy of equine hyperimmune plasma to prevent pneumonia in foals caused by Rhodococcus equi is limited and conflicting. Hypothesis Opsonization with R. equi‐specific hyperimmune plasma (HIP) will significantly increase phagocytosis and decrease intracellular replication of R. equi by alveolar macrophages (AMs) compared to normal plasma (NP). Animals Fifteen adult Quarter Horses were used to collect bronchoalveolar lavage cells. Methods In the first experiment, AMs from 9 horses were pretreated (incubated) with either HIP, NP, or media only (control) and then infected with nonopsonized R. equi. In a second experiment, AMs from 6 horses were infected with R. equi either opsonized with HIP or opsonized with NP. For both experiments, AMs were lysed at 0 and 48 hours and the number of viable R. equi quantified by culture were compared among groups using linear mixed‐effects modeling with significance set at P < .05. Results Opsonization with either HIP or NP increased phagocytosis by AMs (P < .0001) and decreased intracellular survival of organisms in AMs (P < .0001). Pretreating AMs with either HIP or NP without opsonizing R. equi had no effects on phagocytosis or intracellular replication. Conclusions and Clinical Importance Opsonizing R. equi with either NP or HIP decreases intracellular survival of organisms in AMs, but the effect does not appear to be enhanced by using HIP. Mechanisms other than effects on AMs must explain any clinical benefits of using HIP over NP to decrease the incidence of R. equi pneumonia in foals.
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Affiliation(s)
- Aja B Harvey
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Angela I Bordin
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Joana N Rocha
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Jocelyn M Bray
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Noah D Cohen
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
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Folmar CN, Cywes-Bentley C, Bordin AI, Rocha JN, Bray JM, Kahn SK, Schuckert AE, Pier GB, Cohen ND. 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 2019; 33:1493-1499. [PMID: 31034109 PMCID: PMC6524092 DOI: 10.1111/jvim.15511] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 04/17/2019] [Indexed: 11/29/2022] Open
Abstract
Background 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. Hypothesis 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. Animals 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 and Clinical Importance 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.
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Affiliation(s)
- Chelsea N Folmar
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas
| | - Colette Cywes-Bentley
- Department of Medicine, Harvard Medical School, Harvard University, Boston, Massachusetts
| | - Angela I Bordin
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas
| | - Joana N Rocha
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas
| | - Jocelyne M Bray
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas
| | - Susanne K Kahn
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas
| | - Amanda E Schuckert
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas
| | - Gerald B Pier
- Department of Medicine, Harvard Medical School, Harvard University, Boston, Massachusetts
| | - Noah D Cohen
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas
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