MHC Class II Activation and Interferon-gamma Mediate the Inhibition of Neutrophils and Eosinophils by Staphylococcal Enterotoxin Type A (SEA)

Author(s)

Ferreira-Duarte, Ana P. ^[1] ; Pinheiro-Torres, Anelize S. ^[1] ; Anhe, Gabriel F. ^[2] ; Condino-Neto, Antonio ^[3] ; Antunes, Edson ^[2] ; DeSouza, Ivani A. ^[1]

Affiliation

^[1] Fac Med Jundiai, Dept Biol & Physiol, Jundiai - Brazil

^[2] Univ Estadual Campinas, Dept Pharmacol, Campinas, SP - Brazil

^[3] Univ Sao Paulo, Inst Biomed Sci, Dept Immunol, Sao Paulo - Brazil

• Document type: Journal article
• Source: FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY; v. 7, DEC 13 2017.
• Web of Science Citations: 3

Abstract

Staphylococcal enterotoxins are classified as superantigens that act by linking T-cell receptor with MHC class II molecules, which are expressed on classical antigen-presenting cells (APC). Evidence shows that MHC class II is also expressed in neutrophils and eosinophils. This study aimed to investigate the role of MHC class II and IFN-gamma on chemotactic and adhesion properties of neutrophils and eosinophils after incubation with SEA. Bone marrow (BM) cells obtained from BALB/c mice were resuspended in culture medium, and incubated with SEA (3-30 ng/ml; 1-4 h), after which chemotaxis and adhesion were evaluated. Incubation with SEA significantly reduced the chemotactic and adhesive responses in BM neutrophils activated with IL-8 (200 ng/ml). Likewise, SEA significantly reduced the chemotactic and adhesive responses of BM eosinophils activated with eotaxin (300 ng/ml). The inhibitory effects of SEA on cell chemotaxis and adhesion were fully prevented by prior incubation with an anti-MHC class II blocking antibody (2 mu g/ml). SEA also significantly reduced the intracellular Ca2+ levels in IL-8- and eotaxin-activated BM cells. No alterations of MAC-1, VLA4, and LFA-1 a expressions were observed after SEA incubation. In addition, SEA elevated by 3.5-fold (P < 0.05) the INF-gamma levels in BM cells. Incubation of BM leukocytes with IFN-gamma (10 ng/ml, 2 h) reduced both neutrophil and eosinophil chemotaxis and adhesion, which were prevented by prior incubation with anti-MHC class II antibody (2 mu g/ml). In conclusion, SEA inhibits neutrophil and eosinophil by MHC class II-dependent mechanism, which may be modulated by concomitant release of IFN-gamma (AU)

• FAPESP's process: 12/05561-8 - Effect of staphylococcal enterotoxins type A and B on the adhesion and chemotactic response of mice bone marrow granulocytes.
• Grantee: Ana Paula Ferreira Duarte
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 09/16522-0 - Effects of staphylococcal enterotoxins (SEs) on the mice bone marrow mature granulocytes production and functions
• Grantee: Ivani Aparecida de Souza
• Support Opportunities: Research Grants - Young Investigators Grants