Prior and concomitant dehydroepiandrosterone treatment affects immunologic response of cultured macrophages infected with Trypanosoma cruzi in vitro?
DHEA, a steroid hormone synthesized from cholesterol by cells of the adrenal cortex, plays an essential role in enhancing the host's resistance to different experimental infections. Receptors for this hormone can be found in distinct immune cells (especially macrophages) that are known to be the first line defense against Trypanosoma cruzi infection. These cells operate through an indirect pathway releasing nitric oxide (NO) and cytokines such TNF-α and IL-12 which in turn trigger an enhancement of natural killer cells and lymphocytes which finally secrete pro and anti-inflammatory cytokines. The effects of pre- and post-infection DHEA treatment on production of IL-12, TNFα and NO were evaluated. T. cruzi infected macrophages post treated with DHEA displayed enhanced concentrations of TNF-α, IL-12 and NO. Probably, the mechanisms that induced the production of cytokines by infected cells are more efficient when the immune system has been stimulated first by parasite invasion, suggesting that the protective role of DHEA is greater when administered post infection.
Laboratório de Parasitologia, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto - Universidade de São Paulo, Avenida do Café s/n, 14040-903 Ribeirão Preto, SP, Brazil.
Christian C
CC
Kuehn
Luiz Gustavo R
LG
Oliveira
Carla Domingues
CD
Santos
Mariana B
MB
Augusto
Míriam P Alonso
MP
Toldo
José Clóvis
JC
do Prado
D000818:Animals; D014355:Chagas Disease / Q000188:drug therapy / Q000276:immunology* / Q000469:parasitology; D003687:Dehydroepiandrosterone / Q000494:pharmacology*; D018664:Interleukin-12 / Q000276:immunology; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000276:immunology / Q000469:parasitology*; D008297:Male; D009569:Nitric Oxide / Q000276:immunology; D051381:Rats; D017208:Rats, Wistar; D014349:Trypanosoma cruzi / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
D014409:Tumor Necrosis Factor-alpha; D018664:Interleukin-12; D009569:Nitric Oxide; D003687:Dehydroepiandrosterone