Channel catfish NK-like cells are armed with IgM via a putative FcmicroR.
Two-color flow cytometry demonstrated that 4-8% of channel catfish PBL are positive for both F and G IgL chain isotypes, suggesting that they passively acquire serum IgM via a putative FcmicroR. These cells show spontaneous killing toward allogeneic targets, and in vitro stimulation of PBL with allogeneic cells results in an increase of double IgL chain positive cells with a concomitant increase in nonspecific cytotoxicity. Long-term cultures of alloantigen-stimulated PBL contain both sIgM(+) and sIgM(-) cytotoxic cells that transcribe message for the catfish homolog of the FcepsilonR gamma chain, but not for Igmicro and TCR-alpha,-beta, or -gamma chains. Immunoprecipitation of lysates from sIgM(+) NK-like cells with anti-IgM co-immunoprecipitated a putative FcmicroR of approximately 64 kDa. Finally, removal of IgM from sIgM(+) NK-like cells and replacement with anti-hapten antibody enabled antibody-armed effectors to kill haptenated targets that were refractory to killing by effectors armed with normal IgM. This is the first report suggesting that teleost NK-like cells express a putative FcmicroR which participates in antibody-dependent cell-mediated cytotoxicity.
Shen
Linling
L
Department of Microbiology, University of Mississippi, Medical Center, 2500 North State Street, Jackson, MS 39216, USA.
Stuge
Tor B
TB
Evenhuis
Jason P
JP
Bengtén
Eva
E
Wilson
Melanie
M
Chinchar
V Gregory
VG
Clem
L William
LW
Miller
Norman W
NW
D000818:Animals; D000920:Antibody-Dependent Cell Cytotoxicity / Q000276:immunology*; D002460:Cell Line; D005434:Flow Cytometry; D006801:Humans; D007059:Ictaluridae / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology*; D011233:Precipitin Tests; D011961:Receptors, Fc / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D007075:Immunoglobulin M; D011961:Receptors, Fc; C035311:immunoglobulin M receptor