Streptococcal exotoxin B increases interleukin-6, tumor necrosis factor alpha, interleukin-8 and transforming growth factor beta-1 in leukocytes.
Previous reports have shown the presence of streptococcal erythrogenic exotoxin type B (ETB), leukocyte infiltration, interleukin-8 (IL-8), transforming growth factor-beta (TGF-beta) and glomerular proliferation in renal biopsies from patients with acute post-streptococcal glomerulonephritis (APSGN). In addition, increased levels of plasma interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFalpha), and urinary IL-6, have also been reported in this disease. To determine the effect of streptococcal proteins on leukocyte proliferation and leukocyte production of IL-6, TNFalpha, IL-8 and TGF-beta1, we cultured human mononuclear leukocytes with ETB or ETB precursor (ETBP). After 24 h, 48 h and 96 h, culture supernatants were assessed for cytokines by enzyme-linked immunosorbent assay (ELISA), and for leukocyte proliferation by a monoclonal antibody anti-proliferating cellular nuclear antigen (PCNA). A significant increase in all cytokines was found in ETB- or ETBP-treated cultures when compared with controls. A polyclonal anti-ETB antibody diminished the cytokine stimulatory effect of ETB. An increased number of PCNA-positive cells was observed in ETB or ETBP treated cultures at 48 h and 96 h. Cytokine production and proliferation were not correlated. The stimulatory effect of streptococcal exotoxin B on leukocyte cytokine production may be relevant in renal tissue during the course of APSGN.
Viera
Ninoska
N
Instituto de Investigaciones de la Facultad de Odontologia, Universidad del Zulia, Maracaibo, Venezuela.
Pedreanez
Adriana
A
Rincon
Jaimar
J
Mosquera
Jesus
J
D001426:Bacterial Proteins / Q000494:pharmacology*; D002478:Cells, Cultured; D005098:Exotoxins / Q000494:pharmacology*; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis*; D016209:Interleukin-8 / Q000096:biosynthesis*; D007962:Leukocytes / Q000187:drug effects* / Q000276:immunology*; D053773:Transforming Growth Factor beta1 / Q000096:biosynthesis*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
D001426:Bacterial Proteins; D005098:Exotoxins; D015850:Interleukin-6; D016209:Interleukin-8; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha; C027951:erythrogenic toxin