Cytokine response profiles predict species-specific infection patterns in human GI nematodes.
This study investigated associations between pre-treatment cytokine expression and infection patterns, before and after de-worming, in humans exposed to two gastrointestinal nematode species. Quantitative measures of Ascaris lumbricoides and Trichuris trichiura infection (based on faecal egg counts) were estimated immediately before and 8-9 months after treatment in a Cameroonian population. Whole blood cytokine responses to parasite-derived antigens were assayed immediately pre-treatment. An overall measure of the tendency towards species-specific infection (increasing with A. lumbricoides faecal egg counts and decreasing with T. trichiura faecal egg counts) was significantly positively related to IL-10 levels in older (14-57 year) hosts. There was a significant negative influence of IL-5 on reinfection probability in T. trichiura but not A. lumbricoides. This effect coincided with reduced reinfection success in T. trichiura compared to A. lumbricoides. T(H)2 cytokine expression by younger hosts (4-13 year) was negatively associated with contemporary A. lumbricoides faecal egg counts before treatment. Following treatment, the pre-treatment T(H)2 cytokine expression data for younger hosts (now reflecting responsiveness 8-9 months in the past) were negatively associated with T. trichiura faecal egg counts. Taken together, these observations suggest a successional interaction between T(H)2-driven immune responses and species infection over time. However, any differential effects of the measured immune responses on species-specific recruitment, maturation and mortality were superimposed upon (and outweighed by) the effects of other factors favouring coinfection.
Jackson
J A
JA
School of Biology, Nottingham University, Nottingham NG7 2RD, UK.
Turner
J D
JD
Rentoul
L
L
Faulkner
H
H
Behnke
J M
JM
Hoyle
M
M
Grencis
R K
RK
Else
K J
KJ
Kamgno
J
J
Bradley
J E
JE
Boussinesq
M
M
D000293:Adolescent; D000328:Adult; D000818:Animals; D001196:Ascariasis / Q000097:blood / Q000276:immunology; D017164:Ascaris lumbricoides / Q000472:pathogenicity; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000097:blood*; D005260:Female; D005767:Gastrointestinal Diseases / Q000097:blood* / Q000276:immunology; D006801:Humans; D016753:Interleukin-10 / Q000097:blood; D018793:Interleukin-13 / Q000097:blood; D015848:Interleukin-5 / Q000097:blood; D007411:Intestinal Diseases, Parasitic / Q000097:blood / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009349:Nematode Infections / Q000097:blood* / Q000276:immunology; D010270:Parasite Egg Count; D013045:Species Specificity; D014257:Trichuriasis / Q000097:blood / Q000276:immunology; D014258:Trichuris / Q000472:pathogenicity
D016207:Cytokines; D018793:Interleukin-13; D015848:Interleukin-5; D016753:Interleukin-10