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Effect of metalloproteinase from Staphylococcus aureus on in vitro stimulation of human lymphocytes
L Prokesová1, Z Porwit-Bóbr, K Baran
1Laboratory of Special Medical Microbiology and Immunology, 1st Medical Faculty, Charles University, Prague, Czechoslovakia.
Abstract:
Metalloproteinase (MP) produced by the majority of Staphylococcus aureus strains exerts, in a wide concentration range (0.1-100 micrograms/ml), no cytotoxic action on mononuclear leukocytes of human peripheral blood. The enzyme itself does not appreciably stimulate proliferation and differentiation of lymphocytes in culture, but affects the stimulation of both T and B lymphocytes by polyclonal activators. The action is dose-dependent. High doses of MP (100 micrograms/ml) lower the blastic transformation after stimulation with Con A, SpA, NDCM, S. aureus strain Wood 46 and with suboptimal doses of PWM. Optimal concentrations of the enzyme potentiate the stimulation of lymphocytes by PWM, PHA, S. aureus strains Cowan 1 and Wood 46, and by NDCM. The same potentiation effect was achieved whether the enzyme was added concurrently with the mitogen or 18 h later. This implies that the beginning of cell activation is not affected. A high MP concentration decreases the production of Ig in culture after stimulation with PWM whereas lower concentrations of MP enhance this production. Production of Ig after stimulation with NDCM and Wood 46 is decreased by MP. The possible action of exoproteinase from S. Aureus on the immune response during infection is discussed.
Insights
Staphylococcus aureus metalloproteinase (MP) does not harm human leukocytes but modulates lymphocyte responses. Optimal MP concentrations enhance immune cell activation and antibody production, while high doses suppress it.
Area of Science:
- Immunology
- Microbiology
- Biochemistry
Background:
- Staphylococcus aureus is a common pathogen.
- Metalloproteinases (MP) are enzymes produced by S. aureus.
- The effect of MP on human immune cells is not fully understood.
Purpose of the Study:
- To investigate the cytotoxic and immunomodulatory effects of Staphylococcus aureus metalloproteinase (MP) on human peripheral blood mononuclear leukocytes.
- To determine the dose-dependent impact of MP on lymphocyte proliferation, differentiation, and antibody production.
Main Methods:
- Human peripheral blood mononuclear leukocytes were cultured.
- Cells were exposed to varying concentrations of MP (0.1-100 µg/ml).
- Lymphocyte activation was assessed using polyclonal activators (Con A, SpA, NDCM, PWM, PHA) and S. aureus strains. Antibody (Ig) production was measured.
Main Results:
- MP exhibited no cytotoxic effects on leukocytes within the tested concentration range.
- MP modulated lymphocyte activation in a dose-dependent manner.
- Optimal MP concentrations potentiated lymphocyte stimulation and Ig production, while high concentrations suppressed these responses.
Conclusions:
- Staphylococcus aureus metalloproteinase (MP) plays a complex role in modulating the human immune response.
- MP can either enhance or suppress lymphocyte activation and antibody production depending on its concentration.
- Understanding MP's immunomodulatory effects is crucial for comprehending S. aureus pathogenesis.