Ly49G2 receptor blockade reduces tumor burden in a leukemia model but not in a solid tumor model.
BACKGROUND
NK cell activity is regulated in part by inhibitory receptors that bind to MHC class I molecules. It is possible to enhance NK cell cytotoxicity against tumor cells by preventing the interaction of these inhibitory receptors with their MHC class I ligands.


RESULTS
In this study, we determined that Ly49G2 is an inhibitory receptor in AKR mice for self-MHC class I, and AKR Ly49G2 has an identical sequence to BALB/c Ly49G2. Blockade of Ly49G2 receptors in vivo resulted in decreased growth of BW-Sp3 lymphoma cells when the tumor cells were given i.v. but not when the tumor cells were inoculated into the flank forming a solid tumor. However, NK cells were involved in inhibiting the growth of BW-Sp3 tumor cells in the flank.


CONCLUSIONS
These data demonstrate that the effectiveness of inhibitory receptor blockade depends upon the tissue location of the tumor cells.
Barber
Melissa A
MA
Department of Microbiology and Immunology, Dartmouth Medical School, 6W Borwell Bldg, Lebanon, NH 03756, USA.
Zhang
Tong
T
Gagne
Bethany A
BA
Van Ginderachter
Jo A
JA
De Baetselier
Patrick
P
Sentman
Charles L
CL
D000818:Animals; D000950:Antigens, Ly / Q000235:genetics; D001483:Base Sequence; D004195:Disease Models, Animal; D005434:Flow Cytometry; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type / Q000037:antagonists & inhibitors* / Q000235:genetics; D007938:Leukemia / Q000276:immunology / Q000628:therapy*; D051379:Mice; D008969:Molecular Sequence Data; D009374:Neoplasms, Experimental / Q000276:immunology / Q000628:therapy*; D055630:Receptors, NK Cell Lectin-Like; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000950:Antigens, Ly; D037181:Lectins, C-Type; D055630:Receptors, NK Cell Lectin-Like