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Reynolds S, Rafeek RAM, Hamlin A, Lepletier A, Pandey M, Ketheesan N, Good MF. Streptococcus pyogenes vaccine candidates do not induce autoimmune responses in a rheumatic heart disease model. NPJ Vaccines 2023; 8:9. [PMID: 36739443 PMCID: PMC9899064 DOI: 10.1038/s41541-023-00604-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 01/23/2023] [Indexed: 02/06/2023] Open
Abstract
We have developed a candidate vaccine to protect against multiple strains of Streptococcus pyogenes infections. The candidate vaccine contains two synthetic peptides derived from S. pyogenes proteins: the M-protein epitope, p*17 and the IL-8 degrading S. pyogenes Cell-Envelope Proteinase (SpyCEP) epitope, K4S2. In this study we utilise a rat autoimmune valvulitis model that displays both the cardiac and neurobehavioural pathology associated with post-streptococcal sequelae, to assess if the vaccine candidate antigens induce autoimmune complications and inflammatory pathology. Each antigen was conjugated to carrier protein diphtheria toxoid (DT) and independently assessed for potential to induce autoimmune pathology in female Lewis rats. Rats were administered three subcutaneous doses, and one intranasal dose over a four-week study with a two-week recovery period. A positive control group received recombinant S. pyogenes M5 (rM5) protein, and the negative control group received PBS. Rats that received rM5 developed significant cardiac and neurological pathologies. There was no evidence of these pathologies in the PBS control group, or the rats administered either P*17-DT or K4S2-DT. This study provides further preclinical evidence of the safety of the vaccine candidates p*17 and K4S2 and their appropriateness as candidates in human clinical trials.
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Affiliation(s)
- Simone Reynolds
- grid.1022.10000 0004 0437 5432Institute for Glycomics, Griffith University, Southport, Queensland Australia
| | - Rukshan Ahamed Mohamed Rafeek
- grid.1020.30000 0004 1936 7371School of Science & Technology, University of New England, Armidale, New South Wales Australia
| | - Adam Hamlin
- grid.1020.30000 0004 1936 7371School of Science & Technology, University of New England, Armidale, New South Wales Australia
| | - Ailin Lepletier
- grid.1022.10000 0004 0437 5432Institute for Glycomics, Griffith University, Southport, Queensland Australia
| | - Manisha Pandey
- grid.1022.10000 0004 0437 5432Institute for Glycomics, Griffith University, Southport, Queensland Australia
| | - Natkunam Ketheesan
- grid.1022.10000 0004 0437 5432Institute for Glycomics, Griffith University, Southport, Queensland Australia ,grid.1020.30000 0004 1936 7371School of Science & Technology, University of New England, Armidale, New South Wales Australia
| | - Michael F. Good
- grid.1022.10000 0004 0437 5432Institute for Glycomics, Griffith University, Southport, Queensland Australia
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Rafeek RAM, Hamlin AS, Andronicos NM, Lawlor CS, McMillan DJ, Sriprakash KS, Ketheesan N. Characterization of an experimental model to determine streptococcal M protein–induced autoimmune cardiac and neurobehavioral abnormalities. Immunol Cell Biol 2022; 100:653-666. [PMID: 35792671 PMCID: PMC9545610 DOI: 10.1111/imcb.12571] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/28/2022] [Accepted: 07/05/2022] [Indexed: 11/29/2022]
Abstract
Group A streptococcal (GAS) infection is associated with a spectrum of autoimmune diseases including acute rheumatic fever/rheumatic heart disease (ARF/RHD) and neurobehavioral abnormalities. Antibodies against GAS M proteins cross‐react with host tissue proteins in the heart and brain leading to the symptomatology observed in ARF/RHD. As throat carriage of Streptococcus dysgalactiae subspecies equisimilis (SDSE) has been reported to be relatively high in some ARF/RHD endemic regions compared with GAS, and both SDSE and GAS express coiled‐coil surface protein called M protein, we hypothesized that streptococci other than GAS can also associated with ARF/RHD and neurobehavioral abnormalities. Neurobehavioral assessments and electrocardiography were performed on Lewis rats before and after exposure to recombinant GAS and SDSE M proteins. Histological assessments were performed to confirm inflammatory changes in cardiac and neuronal tissues. ELISA and Western blot analysis were performed to determine the cross‐reactivity of antibodies with host connective, cardiac and neuronal tissue proteins. Lewis rats injected with M proteins either from GAS or SDSE developed significant cardiac functional and neurobehavioral abnormalities in comparison to control rats injected with phosphate‐buffered saline. Antibodies against GAS and SDSE M proteins cross‐reacted with cardiac, connective and neuronal proteins. Serum from rats injected with streptococcal antigens showed higher immunoglobulin G binding to the striatum and cortex of the brain. Cardiac and neurobehavioral abnormalities observed in our experimental model were comparable to the cardinal symptoms observed in patients with ARF/RHD. Here for the first time, we demonstrate in an experimental model that M proteins from different streptococcal species could initiate and drive the autoimmune‐mediated cardiac tissue damage and neurobehavioral abnormalities.
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Affiliation(s)
- Rukshan AM Rafeek
- School of Science & Technology University of New England Armidale NSW Australia
| | - Adam S Hamlin
- School of Science & Technology University of New England Armidale NSW Australia
| | | | - Craig S Lawlor
- School of Science & Technology University of New England Armidale NSW Australia
| | - David J McMillan
- School of Science & Technology University of New England Armidale NSW Australia
- School of Science, Technology, Engineering and Genecology Research Centre University of the Sunshine Coast Sippy Downs QLDAustralia
| | - Kadaba S Sriprakash
- School of Science & Technology University of New England Armidale NSW Australia
- Infection and Inflammation Laboratory QIMR Berghofer Medical Research Institute Herston QLDAustralia
| | - Natkunam Ketheesan
- School of Science & Technology University of New England Armidale NSW Australia
- School of Science, Technology, Engineering and Genecology Research Centre University of the Sunshine Coast Sippy Downs QLDAustralia
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Rafeek RAM, Sikder S, Hamlin AS, Andronicos NM, McMillan DJ, Sriprakash KS, Ketheesan N. Requirements for a Robust Animal Model to Investigate the Disease Mechanism of Autoimmune Complications Associated With ARF/RHD. Front Cardiovasc Med 2021; 8:675339. [PMID: 34026876 PMCID: PMC8131511 DOI: 10.3389/fcvm.2021.675339] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 04/09/2021] [Indexed: 01/03/2023] Open
Abstract
The pathogenesis of Acute Rheumatic Fever/Rheumatic Heart Disease (ARF/RHD) and associated neurobehavioral complications including Sydenham's chorea (SC) is complex. Disease complications triggered by Group A streptococcal (GAS) infection are confined to human and determining the early events leading to pathology requires a robust animal model that reflects the hallmark features of the disease. However, modeling these conditions in a laboratory animal, of a uniquely human disease is challenging. Animal models including cattle, sheep, pig, dog, cat, guinea pigs rats and mice have been used extensively to dissect molecular mechanisms of the autoimmune inflammatory responses in ARF/RHD. Despite the characteristic limitations of some animal models, several rodent models have significantly contributed to better understanding of the fundamental mechanisms underpinning features of ARF/RHD. In the Lewis rat autoimmune valvulitis model the development of myocarditis and valvulitis with the infiltration of mononuclear cells along with generation of antibodies that cross-react with cardiac tissue proteins following exposure to GAS antigens were found to be similar to ARF/RHD. We have recently shown that Lewis rats injected with recombinant GAS antigens simultaneously developed cardiac and neurobehavioral changes. Since ARF/RHD is multifactorial in origin, an animal model which exhibit the characteristics of several of the cardinal diagnostic criteria observed in ARF/RHD, would be advantageous to determine the early immune responses to facilitate biomarker discovery as well as provide a suitable model to evaluate treatment options, safety and efficacy of vaccine candidates. This review focuses on some of the common small animals and their advantages and limitations.
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Affiliation(s)
- Rukshan A. M. Rafeek
- School of Science and Technology, University of New England, Armidale, NSW, Australia
| | - Suchandan Sikder
- School of Science and Technology, University of New England, Armidale, NSW, Australia
- Department of Medicine and Surgery, Chattogram Veterinary and Animal Sciences University, Chattogram, Bangladesh
| | - Adam S. Hamlin
- School of Science and Technology, University of New England, Armidale, NSW, Australia
| | | | - David J. McMillan
- School of Science and Technology, University of New England, Armidale, NSW, Australia
- School of Science, Technology, Engineering and Genecology Research Centre, University of the Sunshine Coast, Maroochydore, QLD, Australia
| | - Kadaba S. Sriprakash
- School of Science and Technology, University of New England, Armidale, NSW, Australia
- Queensland Institute of Medical Research Berghofer, Brisbane, QLD, Australia
| | - Natkunam Ketheesan
- School of Science and Technology, University of New England, Armidale, NSW, Australia
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