JSM Cloning and Expression of a NovelMurineAnti-human Fas Antibody

variolls diseases resulting from an abnormality of the FaslFasL system. Howeyer, some anti-Fas antibodies show toxicity, and it is diMcult te investigate their therapeutic and toxicological effect llsing animals because of their species specificity. We previously obtained a murine anti-human Fas mAb, HFE7A. HFE7A reacted with both human and murine Fas, and mitigated lymphadenopathy without any sign of hepatotoxicity in MRLgld!gld mice. It is sllggested that humanized HFE7A would be a therapeutic treatment for variolls diseases resulting from an abnormality of the FasfFasL system. Here we isolated the cDNAs that code for the heavy and light chains of HFE7A and identified the corresponding nucleotide sequences. The recombinant HFE7A was indistinguishable in binding and apoptosisinducing activity to that from a hybridoma cell line. These data proyide essential i"formation for the humanization and c]inica) applicatien of the humanized HFE7A.