Immunomodulatory effects of peptide T on Th 1/Th 2 cytokines.
Peptide T is an octapeptide from the V2 region of HIV-1 gp120. It has been shown to resolve psoriatic lesions--an inflammatory skin disease. The mechanisms of anti-inflammatory actions of peptide T are not well understood. Th1 cytokines such as IL-2, and IFN-gamma are upregulated in psoriasis. These cytokines play a key role in the inflammatory and proliferative processes of psoriasis. The effects of peptide T on Th1 and Th2 cytokines were studied in order to elucidate the mechanisms of antiinflammatory actions of peptide T. It was observed that peptide T at 10(-8) M induces IL-10 production by the human Th2 cell line and PBMC (P < 0.05, ANOVA). Also peptide T at 10(-9) M concentration significantly inhibited IFN-gamma production by PBMC (P < 0.001, ANOVA). Anti IL-10 antibody inhibited the anti-IFN-gamma effect of peptide T (P < 0.05, t-test). Our study shows that peptide T induces IL-10 production and inhibits IFN-gamma production. IL-10 is a potent anti-inflammatory cytokine. It inhibits IL-2 and IFN-gamma production from the T cells and downregulates the expression of TNF-alpha in the antigen presenting cells. Recently, IL-10 has been shown to resolve psoriatic lesions. The effects of peptide T on IL-10 and IFN-gamma production provides a plausible explanation for its clinical efficacy in psoriasis.
Raychaudhuri
S P
SP
Psoriasis Research Institute, Palo Alto, CA 94301, USA.
Farber
E M
EM
Raychaudhuri
S K
SK
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000328:Adult; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015717:Peptide T / Q000494:pharmacology*; D011565:Psoriasis / Q000097:blood
D000276:Adjuvants, Immunologic; D016207:Cytokines; D015717:Peptide T; D016753:Interleukin-10; D007371:Interferon-gamma