Characterization of monoclonal antibodies specific for l4-kDa human group V secretory phospholipase A(2) (hVPLA(2))

Secretory phospholipase A(2) (PLA(2)) consists of several 14-kDa isoforms w ith extensive homology, which makes it difficult to identify a specific iso form, In this study, we have developed and characterized monoclonal antibod ies (MAbs) directed specifically against human group V sPLA(2) (hVPLA(2)) d erived from cultured hybridomas, These hybridomas were produced from the fu sion of BALB/c-derived myeloma s/p20-Ag14 and splenocytes from mice immuniz ed with purified recombinant hVPLA(2), Three hybridomas secreting MAbs, MCL -3G1, MCL-2A5, and MCL-1B7, were selected and subcloned on the basis of the ir specificity to recognize hVPLA(2) using solid-phase enzyme-linked immuno adsorbent assay (ELISA), The purified MAbs demonstrated a common pattern of immunoreactivity to hVPLA(2), but not to human group IIa isoform (hIIaPLA( 2)), Isotype analysis indicates that these hybridomas are of the IgG(1) typ e. Under reducing conditions, MCL-3G1 sensitively detected hVPLA(2) and dem onstrated no cross-reactivity to either hIIaPLA(2) or group IV cytosolic PL A(2), Although specific for hVPLA(2), a relatively modest signal was recogn ized with MCL-1B7 and MCL-2A5. These newly developed MAbs allow for determi nation of tissue distribution and cell-specific functions of hVPLA(2).