Immunogenetics

, Volume 59, Issue 1, pp 77–91

Channel catfish leukocyte immune-type receptors contain a putative MHC class I binding site

  • James L. Stafford
  • Eva Bengtén
  • Louis Du Pasquier
  • Norman W. Miller
  • Melanie Wilson
Original Paper

DOI: 10.1007/s00251-006-0169-3

Cite this article as:
Stafford, J.L., Bengtén, E., Du Pasquier, L. et al. Immunogenetics (2007) 59: 77. doi:10.1007/s00251-006-0169-3

Abstract

The recent identification of a large and diverse family of leukocyte immune-type receptors (IpLITRs) in channel catfish (Ictalurus punctatus) indicates that immunoglobulin superfamily (IgSF) members related to both mammalian Fc receptors (FcRs) and leukocyte receptor complex (LRC)-encoded proteins exist in fish. In the present study, it was found that IpLITR messages were preferentially up regulated in catfish peripheral blood leukocytes (PBL) and clonal cytotoxic T cells (CTL) after alloantigen stimulation. Detailed sequence analyses of the expressed IpLITR cDNAs from two clonal CTL lines indicated an unexpectedly large array of putative activatory and inhibitory IpLITR-types containing variable numbers of extracellular immunoglobulin (Ig)-like domains. Importantly, all expressed IpLITRs shared similar membrane distal Ig domains (i.e., D1 and D2), suggesting that they may bind a common type of ligand. Sequence alignments and comparative homology modeling revealed that IpLITR domains, D1 and D2, have similar predicted 3-D structural properties with the corresponding domains of the human LRC-encoded leukocyte Ig-like receptor (LILR) family. Furthermore, conservation of key major histocompatibility class I (MHC I)-binding residues were located at similar positions within the membrane distal tip of D1 between representative IpLITRs and group 1 LILRs. Taken together, these results suggest that fish LITRs have an orthologous relationship to LRC-encoded receptors such as the human LILRs and could potentially function as a diverse family of MHC class I-binding receptors.

Keywords

Leukocyte receptor complex (LRC)Immunoglobulin superfamily (IgSF)MHC class ILeukocyte Ig-like receptors (LILRs)TeleostsEvolution

Supplementary material

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • James L. Stafford
    • 1
  • Eva Bengtén
    • 1
  • Louis Du Pasquier
    • 2
  • Norman W. Miller
    • 1
  • Melanie Wilson
    • 1
  1. 1.Department of MicrobiologyUniversity of Mississippi Medical CenterJacksonUSA
  2. 2.Institute of Zoology and Evolutionary BiologyUniversity of BaselBaselSwitzerland