Affiliation:
1. Department of Medical Zoology. Kyoto Prefectural University of Medicine, Kyoto. Japan
Abstract
SUMMARY
Some cysteine proteases such as papain and those of mites and schistosomes have potent allergenic properties. To clarify the allergenicity of nematode cysteine proteases, the enzyme was purified from the intestinal nematode Nippostrongylus brasiliensis using cation exchange chromatography and gel filtration chromatography. The purified protease, of 16 kD and pi 8-5, showed maximum enzyme activity at pH 55 and substrate preference for Z-Phe-Arg-MCA. The specific inhibitors of cysteine protease leupeptin, iodoacetic acid, and E-64. completely suppressed the activity, indicating that the purified enzyme belongs to the cysteine protease family. Cysteine protease activity was found not only in somatic extract, but also in the excretory-secretory (ES) product of the nematode. When anti-cysteine protease immunoglobulin isotypes were examined in sera from rats infected with N. brasiliensis. a high level of IgG1 and a lower level of IgE antibody were detected. Depletion of IgG antibodies from the sera using protein G affinity columns resulted in a marked increase in reactivity of anti-cysteine protease IgE with the antigen, possibly due to the removal of competing IgG antibodies. In contrast to IgE and lgG1. production of anti-cysteine protease IgG2a was negligible. These results indicate that the nematode cysteine protease preferentially evokes an IgE/IgG1 antibody response.
Publisher
Oxford University Press (OUP)
Subject
Immunology,Immunology and Allergy
Reference39 articles.
1. Production and activities of IgE in helminth infection;Jarrett;Prog Allergy,1982
2. IgE production in human helminth infection. Reciprocal interrelationship between IL-4 and IFN-7.;King;J Immunol,1993
3. Suppression of in vivo polyclonal IgH responses by monoclonal antibody to the lymphokine B-cell stimulatory factor 1;Finkelman;Proc Natl Acad Sci USA,1986
4. Interleukin 4 is important in protective immunity to a gastrointestinal nematode infection in mice;Urban;Proc Natl Acad Sci USA,1991
5. Ablation of eosinophil and IgE responses with anti-IL-5 or anti-lL-4 antibodies fails to affect immunity against Schistosoma mansoni in the mouse;Sher;J Immunol,1990
Cited by
20 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献