Open AccessM ycobacterium tuberculosis H 37 R v is more effective compared to vaccine strains in modulating neutrophil functions: an in vitro study
Author(s) -
Nancy Hilda J.,
Selvaraj Anbalagan,
Das Sulochana D.
Publication year - 2012
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2012.01025.x
Subject(s) - biology , microbiology and biotechnology , chemokine , tlr2 , immunology , cxcr3 , secretion , toll like receptor , tlr4 , chemokine receptor , immune system , innate immune system , biochemistry
Neutrophils are the primary cells contributing to initial defense against mycobacteria. Yet, little is known about the potential of various mycobacterial strains to stimulate neutrophils. This study was focused to compare the differential capacity of vaccine strains, M ycobacterium bovis bacillus C almette– G uerin ( BCG ) and M ycobacterium indicus pranii ( M w), and laboratory strain H 37 R v to activate and enhance neutrophil functions. The expression of phenotypic markers like F cγ receptor, toll‐like receptor ( TLR ), and chemokine receptor; secretion of pro‐inflammatory cytokines; and the rate of apoptosis were studied in infected neutrophils. Increased expression of CD 32, CD 64, TLR 4, and CXCR 3; increased TNF ‐α secretion; and downregulation of early apoptosis were observed in H 37 R v‐infected neutrophils. Among the vaccine strains, BCG increased the expression of only CD 32 on neutrophils, while M w was comparatively ineffective. To understand the paracrine role of neutrophils, the supernatants from infected neutrophils were used to stimulate monocytes and T helper cells. The secretory molecules from all infected neutrophils increased the expression of CCR 5 on monocytes, whereas only H 37 R v‐infected supernatant increased the expression of CCR 7 on monocytes and CD 69 on T cells. Thus, H 37 R v was more effective in activating neutrophils and in turn stimulating monocytes and T cells. By comparison, vaccine strains were less effective in modulating neutrophil functions.