American cockroach Cr-PI allergen induces lymphocyte proliferation and cytokine production in atopic patients.
BACKGROUND
Previous studies have shown cockroach-induced antigen-specific IgE-mediated asthma. In cockroach-infested areas, more then 50% of asthmatic subjects may have positive skin reactions to this allergen. Partial purified Cr-PI allergen from American cockroaches contains allergens with molecular weights of 72 and 78 kDa; however, little is known about its effect on the lymphocyte proliferation and cytokine production.


OBJECTIVE
IgE synthesis is known to be regulated by interleukin-4 (IL-4) and interferon gamma (IFN gamma). Therefore, we studied Cr-PI allergen-induced cytokine production in atopic patients and healthy normal controls to understand each factors' role in the disease.


METHODS
Peripheral blood mononuclear cells (PBMC) from cockroach skin-sensitive patients and controls were stimulated with mitogen and Cr-PI for proliferative response and cytokine production. Cr-PI antigen-specific T-cell cultures of atopic patients and healthy normal controls were used to test Cr-PI-induced proliferation and cytokine mRNA expression.


RESULTS
PMBC of atopic subjects showed a significantly (P < 0.01) higher stimulation index for Cr-PI induced proliferation (SI = 11.8 +/- 3.7) when compared with that of non-atopic subjects (SI = 4.1 +/- 0.8) and cord bloods (SI = 2.1 +/- 0.4). Cr-PI-induced IL-4 was observed only in the PBMC of atopic patients, whereas Cr-PI-induced IFN gamma was detected in both atopic patients and normal controls. Likewise, Cr-PI-induced IL-4 mRNA expression in T-cell cultures was detected in all atopics but only one of nine controls.


CONCLUSIONS
IL-4 mRNA expression and IL-4 production in PBMC and T-cell cultures of atopic patients showed good correlation with clinical symptoms, skin-reactivity, specific IgE and proliferative response to Cr-PI. These results suggests that cockroach allergen may be a hidden cause of asthma and other atopic diseases.
Jeng
K C
KC
Department of Medical Research, Taichung Veterans General Hospital, Taiwan, Republic of China.
Liu
M T
MT
Wu
C H
CH
Wong
D W
DW
Lan
J L
JL
D000328:Adult; D000368:Aged; D000485:Allergens / Q000276:immunology*; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D003058:Cockroaches / Q000276:immunology*; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology*; D007371:Interferon-gamma / Q000096:biosynthesis / Q000235:genetics; D015847:Interleukin-4 / Q000096:biosynthesis / Q000235:genetics; D008213:Lymphocyte Activation; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger; D012882:Skin Tests; D013601:T-Lymphocytes / Q000276:immunology*
D000485:Allergens; D012333:RNA, Messenger; D015847:Interleukin-4; D007371:Interferon-gamma