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Protection of rats against Mycoplasma arthritidis-induced arthritis by active and passive immunizations with two
1Department of Microbiology, University of South Dakota School of Medicine, Vermillion 57069-2390, USA. LWASHBUR@SUNBIRD.USD.EDU
Abstract:
We previously identified two surface-exposed Mycoplasma arthritidis protein antigens, designated MAA1 and MAA2, that may be involved in cytadherence. Since adherence to host tissues is an important first step in most bacterial infections, we suggest that MAA1 and MAA2 may be virulence factors for M. arthritidis. In order to provide evidence for such a role, we conducted a series of experiments in which rats were actively immunized with each of these proteins purified from sodium dodecyl sulfate-polyacrylamide gels or passively immunized with poly- or monoclonal antibodies against MAA1 and MAA2. In each case, immunity against MAA1 and MAA2 conferred at least partial protection against M. arthritidis-induced disease. The greatest protection was achieved by passive immunization with monoclonal antibody A9a, directed against a surface-exposed epitope of putative adhesin MAA1. Because protective immunity in most bacterial infections is directed against major virulence factors, these results suggest that MAA1 and MAA2 may play a role in the pathogenesis of M. arthritidis-induced arthritis of rats, possibly by mediating initial colonization of joint tissues.
Insights
Mycoplasma arthritidis surface proteins MAA1 and MAA2 may be key virulence factors. Immunizing rats against these proteins provided protection against M. arthritidis-induced disease, suggesting their role in pathogenesis.
Area of Science:
- Microbiology
- Immunology
- Pathogenesis
Background:
- Mycoplasma arthritidis is a pathogen causing arthritis in rats.
- Surface-exposed protein antigens MAA1 and MAA2 were previously identified.
- Cytadherence is a crucial initial step in bacterial infections, suggesting MAA1 and MAA2 could be virulence factors.
Purpose of the Study:
- To investigate the role of MAA1 and MAA2 as virulence factors in M. arthritidis-induced arthritis.
- To determine if immunity against MAA1 and MAA2 confers protection against M. arthritidis infection.
Main Methods:
- Active immunization of rats with purified MAA1 and MAA2 proteins.
- Passive immunization of rats with polyclonal and monoclonal antibodies against MAA1 and MAA2.
- Assessment of protection against M. arthritidis-induced disease.
Main Results:
- Both active and passive immunization against MAA1 and MAA2 conferred partial protection against M. arthritidis-induced disease.
- Passive immunization with monoclonal antibody A9a (targeting MAA1) provided the greatest protection.
- These findings suggest MAA1 and MAA2 are involved in M. arthritidis pathogenesis.
Conclusions:
- MAA1 and MAA2 are likely virulence factors for Mycoplasma arthritidis.
- These proteins may mediate initial colonization of joint tissues, contributing to arthritis development.
- Targeting MAA1 and MAA2 could be a strategy for preventing or treating M. arthritidis infections.
