TI  - Characterization of the  <prot>CD30L</prot>  binding domain on the human  <prot>CD30</prot>  molecule
      using anti-<prot>CD30</prot> antibodies.
PG  - 43-8
AB  -  <prot>CD30</prot>and its counter-receptor  <prot><prot>CD30</prot> ligand</prot> (<prot>CD30L</prot>)  are members of the
       TNF-receptor / <prot>TNFalpha</prot>  superfamily and function to regulate lymphocyte
      survival and differentiation. Several monoclonal antibodies (MAbs) have
      been developed against <prot>CD30</prot> and, based on mutual inhibition assays, are
      grouped into three nonoverlapping serologic clusters. However, the
      relationship between the epitopes recognized by the antibodies comprising
      each cluster and the binding domain for <prot>CD30L</prot> is not known. Using a
      soluble <prot>CD30L</prot>/<prot>CD8alpha</prot> chimeric protein, we assessed the ability of
      anti-<prot>CD30</prot> MAb to inhibit the binding of  <prot>CD30L</prot>  to  <prot>CD30</prot>  expressed by the
      CD30+ Karpas 299 cell line.  <prot>CD30L</prot>  binding by  <prot>CD30</prot>  is blocked by MAb that
      recognize epitopes belonging to cluster Group A (like Ber-H2, Ber-H8, and
      HRS-4) as well as cluster Group C (like HeFi-1 and M44). Cluster Group B
      antibodies, including M67 and Ki-1, do not affect  <prot>CD30L</prot>  binding to  <prot>CD30</prot> .
      The pattern of <prot>CD30L</prot> binding inhibition shows only limited correspondence
      to the functional capacity of some anti-<prot>CD30</prot> MAb to trigger <prot>CD30</prot>
      signaling. Finally, we demonstrate that the anti-<prot>CD30L</prot> MAb M81 also
      completely inhibits  <prot>CD30</prot> / <prot>CD30L</prot>  interaction. This information is useful for
      applying these MAbs in functional studies to further investigate the
      <prot>CD30</prot>/<prot>CD30L</prot> system and for designing assays for soluble <prot>CD30L</prot>.
AD  - Division of Hematology/Oncology, Cardinal Bernardin Cancer Center, Loyola
