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Preparation of various fractions from Mycobacterium smegmatis, their arthritogenicity and their preventive effect on
Abstract:
Cell walls of Mycobacterium smegmatis were able to produce much more severe arthritis in rats than the delipidated cells, whereas cell envelope and cell membrane fractions were unable to produce the disease. The lysozyme-solubilized product was able to produce mild disease with only 30% of incidence with an optimum dose, whereas the higher and the lower doses did not produce the disease. The rats immunized with cell envelope, cell membrane fraction and nonarthritogenic doses of lysozyme-solubilized product were protected against the subsequent homologous and heterologous challenge of delipidated cells. It was discussed that this preventative effect can be the result of antigenic competition between the arthritogenic and nonarthritogenic components of M. smegmatis. On the other hand, all the fractions separated here were able to serve as an immunoadjuvant in terms of inducing delayed hypersensitivity to ovalbumin in guinea pigs.
Insights
Mycobacterium smegmatis cell walls induce severe arthritis in rats. Fractions of the cell envelope and membrane, however, protected against disease, suggesting antigenic competition may prevent arthritis.
Area of Science:
- Immunology
- Microbiology
- Rheumatology
Background:
- Mycobacterium smegmatis is a non-pathogenic mycobacterium.
- Components of mycobacterial cell walls are known to induce inflammatory responses.
Purpose of the Study:
- To investigate the arthritogenic potential of Mycobacterium smegmatis cell wall components.
- To explore the immunoprotective effects of M. smegmatis fractions against arthritis induction.
- To assess the adjuvant properties of M. smegmatis fractions.
Main Methods:
- Induction of arthritis in rats using different fractions of Mycobacterium smegmatis.
- Immunization of rats with cell envelope, cell membrane, and lysozyme-solubilized products.
- Challenge with delipidated cells to assess protection.
- Evaluation of delayed-type hypersensitivity to ovalbumin in guinea pigs.
Main Results:
- Mycobacterium smegmatis cell walls induced severe arthritis in rats.
- Delipidated cells, cell envelope, and cell membrane fractions did not induce significant arthritis.
- A lysozyme-solubilized product induced mild arthritis at an optimal dose.
- Immunization with cell envelope, cell membrane, and non-arthritogenic doses of the lysozyme-solubilized product conferred protection against arthritis.
- All tested fractions acted as immunoadjuvants, enhancing delayed hypersensitivity to ovalbumin.
Conclusions:
- Specific components of Mycobacterium smegmatis cell walls are arthritogenic.
- Certain M. smegmatis fractions can induce protective immunity against arthritis, potentially through antigenic competition.
- M. smegmatis fractions possess immunoadjuvant properties relevant for vaccine development.