title: Immunity to onchocerciasis: putative immune persons produce a Th1-like response to Onchocerca volvulus.
abstract: Immunity to Onchocerca volvulus (Ov) infection is suggested by the presence of putatively immune (PI) subjects in a region of Ecuador in which Ov is endemic. PI subjects were identified by traditional diagnostic methods combined with a polymerase chain reaction-based assay for Ov DNA in skin snips. Responses of peripheral blood mononuclear cells (PBMC) from the PI group (n = 16) were compared with those of persons with active infection (microfiladermic [MF] subjects; n = 51). PBMC of PI subjects proliferated significantly more to Ov antigen (OvAg; P < .009) than did PBMC of MF persons but less to streptolysin-O (P < .001). Cytokine analysis of PBMC culture supernatants revealed that PI subjects (n = 11) produced significantly more interferon-gamma to OvAg than did those in the MF group (n = 18; P = .018), less interleukin (IL)-5 to nonparasite antigen (P = .003) and mitogen (P = .012), and less IL-10 spontaneously (P = .016). Thus, immunity to Ov may in part be mediated by an antigen-specific Th1-type response.
authors.affiliation: Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: L H
authors.initials: LH
authors.lastname: Elson
authors.forename: M
authors.initials: M
authors.lastname: Calvopiña
authors.forename: W
authors.initials: W
authors.lastname: Paredes
authors.forename: E
authors.initials: E
authors.lastname: Araujo
authors.forename: J E
authors.initials: JE
authors.lastname: Bradley
authors.forename: R H
authors.initials: RH
authors.lastname: Guderian
authors.forename: T B
authors.initials: TB
authors.lastname: Nutman
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D017181:Onchocerca volvulus / Q000276:immunology*; D009855:Onchocerciasis / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*
chemical_list: D007376:Interleukin-2; D016753:Interleukin-10; D007371:Interferon-gamma