Mycobacterium tuberculosis-induced activation accelerates apoptosis in peripheral blood neutrophils from patients with active tuberculosis.
The activation of circulating polymorphonuclear neutrophils (PMN) from patients with active tuberculosis (TB-PMN) may be associated with induction of apoptosis. Spontaneous or Mycobacterium tuberculosis (MTB)-induced apoptosis of PMN were evaluated by microscopy, DNA content, and their binding to Annexin V at 0, 3, and 18 h. In addition, the expression of CD11b and of CD16 were evaluated as parameters of activation and apoptosis, respectively. Recently isolated TB-PMN showed a higher CD11b expression than normal PMN (N-PMN), but there were no features of apoptosis, even though an enhancement of Fas expression was observed. Spontaneous apoptosis was accelerated in TB-PMN at 3 h, but no differences were observed in TB- and N-PMN at 18 h of culture. When stimulated with MTB, both TB- and N-PMN steadily increased CD11b expression along the culture period. MTB induced apoptosis of N-PMN at 3 h with loss of CD16 expression. By contrast, MTB delayed the apoptotic rate of TB-PMN, preserving the CD16 receptor at 3 h, whereas it accelerated apoptosis at 18 h, increasing at the same time the expression of CD11b. Taken together, these data suggest that the acceleration of apoptosis observed in TB-PMN could be associated with the MTB-induced activation.
Alemán
Mercedes
M
Departamento de Inmunología, Instituto de Investigaciones Hematológicas, Academia Nacional de Medicina, Buenos Aires, Argentina.
García
Ana
A
Saab
María A
MA
De La Barrera
Silvia S
SS
Finiasz
Marta
M
Abbate
Eduardo
E
Sasiain
María C
MC
D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000502:physiology; D039481:CD11b Antigen / Q000378:metabolism; D002478:Cells, Cultured; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D009169:Mycobacterium tuberculosis / Q000472:pathogenicity*; D009504:Neutrophils / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology*; D017452:Receptors, IgG / Q000378:metabolism; D014376:Tuberculosis / Q000097:blood* / Q000382:microbiology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D019014:fas Receptor / Q000378:metabolism
D017304:Annexin A5; D039481:CD11b Antigen; D016209:Interleukin-8; D017452:Receptors, IgG; D014409:Tumor Necrosis Factor-alpha; D019014:fas Receptor