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Effect of staphylococcal enterotoxins type a and b on the adhesion and chemotactic response of mice bone marrow granulocytes

Grant number: 12/05561-8
Support type:Scholarships in Brazil - Master
Effective date (Start): July 01, 2012
Effective date (End): June 30, 2014
Field of knowledge:Health Sciences - Pharmacy
Principal Investigator:Ivani Aparecida de Souza
Grantee:Ana Paula Ferreira Duarte
Home Institution: Faculdade de Medicina de Jundiaí (FMJ). Prefeitura Municipal de Jundiaí. Jundiaí , SP, Brazil
Associated research grant:09/16522-0 - Effects of staphylococcal enterotoxins (SEs) on the mice bone marrow mature granulocytes production and functions, AP.JP

Abstract

The staphylococcal enterotoxins (SEs) are proteins produced and secreted by the gram-positive bacterium Staphylococcus aureus, and are responsible for most of the pathological conditions seen in infections caused by S. aureus, including the pulmonary infections in hospitalar environment. Previous studies carried out in humans have reported a correlation between levels of IgE antibodies to SEs and respiratory diseases exacerbation, including allergic asthma. However, little is known about the mechanisms underlying such inflammatory exacerbation in asthmatic individuals under exposure to SEs. Our recently studies have been showing that staphylococcal enterotoxin type A (SEA) and type B (SEB), given intratracheally to rats and mice, are able to induce a marked increase on mature and immature granulocyte (neutrophil/eosinophil) counts in bone marrow. Thus, the action of SEs on bone marrow can represent an important step on the mechanism by the SEA (or SEB) pre-exposition can exacerbate the allergic pulmonary inflammation in atopic human (BACHERT et al., 2007; ROSSI & MONASTEROLO, 2004) and in animal experimental models (MARIANO et al., 2010). However, little is known about the SEs actions on the function of bone marrow granulocytes. Therefore, the aim of this study is investigate the ability of adhesion and quimiotactic response in vitro of mature granulocytes from mice SEs-treated bone marrow. We also intend invastigate the effect of in vitro incubation with SEs of naive mice bone marrow granulocyte on adhesion and quimiotatic response. Another aim of this study is to investigate the expression of the adhesion molecules such as VLA-4, LFA-1 e MAC-1 in bone marrow granulocytes and the levels of citokynes (IL-5 and IL-4) and quimokines (eotaxina, SDF-1±;CXCL12 e KC;CXCL1) on bone marrow supernatants from mice SEs-treated . Taken in consideration the high number of hospital infections induced by Staphylococcus aureus, and the recent evidences that SEs are the main ethiologic factor for alergic respiratory diseases, the findings from this project can provide advancement on the elucidation of the SEs mechanisms during Staphylococcus aureus pulmonary infections and on the allergic exacerbations by gram-positive bacterial exposition.

Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
FERREIRA-DUARTE, ANA P.; PINHEIRO-TORRES, ANELIZE S.; ANHE, GABRIEL F.; CONDINO-NETO, ANTONIO; ANTUNES, EDSON; DESOUZA, IVANI A. MHC Class II Activation and Interferon-gamma Mediate the Inhibition of Neutrophils and Eosinophils by Staphylococcal Enterotoxin Type A (SEA). FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY, v. 7, DEC 13 2017. Web of Science Citations: 1.

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