Nonspecific Cytotoxic Cell Receptor Protein-1: A Novel (Predicted) Type III Membrane Receptor on the Teleost Equivalent of Natural Killer Cells Recognizes Conventional Antigen

• Published in: Cellular immunology Vol. 187; no. 1; pp. 19 - 26
• Main Authors: Evans, Donald L., Leary, John H., Jaso-Friedmann, Liliana
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 10.07.1998
• Subjects: Algorithms; Amino Acid Sequence; Animals; Antibodies, Monoclonal; Antigens - genetics; Antigens - metabolism; Binding Sites - genetics; Binding, Competitive; Catfishes - immunology; Cytotoxicity, Immunologic; Enzyme-Linked Immunosorbent Assay; Epitopes - chemistry; Epitopes - genetics; Female; Humans; In Vitro Techniques; Killer Cells, Natural - immunology; Male; Molecular Sequence Data; Peptides - chemistry; Peptides - genetics; Peptides - immunology; Receptors, Antigen - chemistry; Receptors, Antigen - classification; Receptors, Antigen - metabolism; Structure-Activity Relationship
• ISSN: 0008-8749; 1090-2163
• DOI: 10.1006/cimm.1998.1310

The phylogenetic model for “conventional” antigen recognition by NK cells may be a protein (NCCRP-1) recently identified from catfish nonspecific cytotoxic cells (NCC). NCCRP-1 may be a Type III membrane protein. The antigen binding domain was identified by competition experiments using synthetic peptides. Within this domain, a 38-mer peptide (aa 104–140) inhibited NCC killing of IM-9, HL-60, NC-37, U937, and MOLT-4 target cells. Biotinylated 38-mer also bound to IM-9 target cells. A mab which inhibited conjugate formation between NCC and target cells also bound to the 38-mer. Nonbiotinylated 38-mer inhibited mab 5C6 binding to immobilized homologous biotinylated peptide in cold competition ELISA experiments. Peptide 104–140 was truncated into two peptides. Amino acid 104–119 bound to (68%) and inhibited lyis of IM-9 target cells, whereas aa 120–140 had no activity. A predicted structure–function algorithm suggested an N-terminal domain containing BOX-1 motifs for cytokine activation; a C-terminal domain containing abundant phosphorylation sites (i.e., Y, S, and T amino acids); and an extracellular antigen binding domain..