title: In situ expression of interleukin-10 and interleukin-12 in active human cutaneous leishmaniasis.
abstract: Th1-type cellular immune responses (interferon-gamma) play a critical role in protection against Leishmania spp. infection, whereas Th2-type cytokines (interleukin (IL)-4, IL-10) have a counter-protective effect. IL-12, a potent inducer of Th1-type cellular immune responses, may play a pivotal role in the development of a protective response. We found that IL-10 and IL-12 mRNAs were expressed in most lesions of individuals with active cutaneous leishmaniasis. The quantity of IL-12 mRNA was highly variable but correlated strongly with the level of interferon-gamma expression. IL-12 expression also paralleled the expression of IL-10, a potent in vitro suppressor of IL-12 and interferon-gamma production. The more chronic, non-healing lesions generally had higher levels of IL-12 mRNA indicating that the expression of this cytokine alone was not sufficient to induce healing. Although the in situ production of IL-10 did not appear to block IL-12 expression, IL-10 may still promote disease by direct suppression of macrophage activation.
authors.affiliation: Department of Medicine, University of Texas Health Science Center, San Antonio, USA.
authors.forename: P C
authors.initials: PC
authors.lastname: Melby
authors.forename: F
authors.initials: F
authors.lastname: Andrade-Narvaez
authors.forename: B J
authors.initials: BJ
authors.lastname: Darnell
authors.forename: G
authors.initials: G
authors.lastname: Valencia-Pacheco
mesh_terms: D000293:Adolescent; D000328:Adult; D015139:Blotting, Southern; D002648:Child; D005260:Female; D015870:Gene Expression; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis / Q000235:genetics; D016753:Interleukin-10 / Q000096:biosynthesis* / Q000235:genetics; D018664:Interleukin-12 / Q000096:biosynthesis* / Q000235:genetics; D016773:Leishmaniasis, Cutaneous / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D016753:Interleukin-10; D018664:Interleukin-12; D007371:Interferon-gamma