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Cholera toxin (choleragen)-polymorphonuclear leukocyte interactions: effect on migration in vitro and Fc gamma
M Niemialtowski1, W Klucinski, K Malicki
1Department of Microbiology, Faculty of Veterinary Medicine, Warsaw Agricultural University, Grochowska, Poland.
Abstract:
PMNL leukocytosis is a feature common to many types of infectious and inflammatory diseases. How PMNL are recruited to tissues is not yet clear although it is a question that has considerable clinical importance. We investigated the function of PMNL which migrated through an artificial barrier (Chinese hamster ovary (CHO) cells, collagen and nylon cloth membrane) subjected to CT or choleragenoid treatment toward plain medium (the same RPMI in the upper and lower chamber) or medium containing chemotactic factor (fMLP or LPS or ZAS). CT treatment significantly (P < 0.01) reduced the Fc gamma R expression on the surface of PMNL. The PMNL functions, namely, migration, phagocytic activity and intracellular killing of staphylococci, also have been reduced significantly (P < 0.01). Fc gamma R expression and some functions of PMNL that migrate to chemoattractants were reduced, irrespective of the presence or absence of CT; however, the inhibitory effect of CT on PMNL function was observed only when PMNL migrate to the lower chamber without chemotactic factor. On the other hand choleragenoid treatment of CHO cells did not have any significant influence on PMNL function and Fc gamma R expression. In conclusion, our experiments demonstrate that CT reduces EAFc rosetting and the Fc gamma R-dependent phagocytic and bactericidal activity of bovine blood PMNL.
Insights
Cholera toxin (CT) impairs polymorphonuclear leukocyte (PMNL) function, reducing their ability to fight infections. This study shows CT significantly reduces PMNL migration and killing activity, crucial for immune responses.
Area of Science:
- Immunology
- Cell Biology
- Microbiology
Background:
- Polymorphonuclear leukocytes (PMNL) are vital for fighting infections and inflammation.
- The mechanisms of PMNL recruitment to infection sites are not fully understood.
- Understanding PMNL function is critical for clinical applications in infectious and inflammatory diseases.
Purpose of the Study:
- To investigate the effect of cholera toxin (CT) and choleragenoid on PMNL function.
- To determine how CT impacts PMNL migration, phagocytosis, and bacterial killing.
- To assess the role of Fc gamma R expression in CT-mediated PMNL dysfunction.
Main Methods:
- PMNL migration through artificial barriers (CHO cells, collagen, nylon) was analyzed.
- PMNL were exposed to CT or choleragenoid treatment.
- PMNL function was tested in response to chemotactic factors (fMLP, LPS, ZAS) or plain medium.
- Fc gamma R expression on PMNL surface was measured.
Main Results:
- CT treatment significantly reduced Fc gamma R expression on PMNL (P < 0.01).
- CT significantly impaired PMNL migration, phagocytic activity, and intracellular killing of staphylococci (P < 0.01).
- CT's inhibitory effect on PMNL function was most pronounced when migrating without chemotactic factors.
- Choleragenoid treatment did not significantly affect PMNL function or Fc gamma R expression.
Conclusions:
- CT significantly reduces Fc gamma R-dependent functions of bovine PMNL, including phagocytosis and bactericidal activity.
- CT impairs PMNL's ability to migrate and combat bacterial infections.
- These findings highlight CT as a potent inhibitor of key PMNL immune functions.