Open AccessCysteine protease of the nematode Nippostrongylus brasiliensis preferentially evokes an IgE/IgG1 antibody response in rats
Author(s) -
KAMATA I.,
YAMADA M.,
UCHIKAWA R.,
MATSUDA S.,
ARIZONO N.
Publication year - 1995
Publication title -
clinical & experimental immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 135
eISSN - 1365-2249
pISSN - 0009-9104
DOI - 10.1111/j.1365-2249.1995.tb06638.x
Subject(s) - cysteine protease , nippostrongylus brasiliensis , proteases , protease , cysteine , biochemistry , biology , affinity chromatography , immunoglobulin e , antibody , iodoacetic acid , enzyme , microbiology and biotechnology , immunology , immune system
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.