In the present study we established a new monoclonal antibody, JNK-1, which
recognizes all cells recognized by CD57/HNK-1 mAb. JNK-1 and CD57 mAbs inh
ibited the binding of each other, suggesting that the molecules they recogn
ize are either identical or sufficiently close to cause steric hindrance in
the binding assay. JNK-1 mAb detected the 110-kDa protein, which is identi
cal to the protein recognized by CD57/HNK-1 mAb in Western immunoblot analy
sis combined with immunoprecipitation. Therefore, JNK-1 mAb appears to reco
gnize homogeneous molecules identified by the currently available CD57 mAb.
Notably, JNK-1 mAb is composed of mouse IgG1 heavy chains, and thus can be
used easily in immunoprecipitation, which cannot easily be performed with
the available CD57 mAb because it is an IgM isotype. Thus. JNK-1, which is
an IgG isotype, may present a useful tool to elucidate the CD57 protein. (C
) 2000 Elsevier Science B.V. All rights reserved.