An H-2Ld hybrid molecule with a Qa-2 alpha-3 domain and phosphatidyl-inositol anchor is not recognized by H-2Ld-specific cytotoxic T lymphocytes.
Ld/Q7d, a hybrid molecule consisting of alpha-1 and alpha-2 domains from H-2Ld and alpha-3 and carboxy-end components from Q7d, was expressed on the surface of CRL-3A rat liver cells. This molecule retained serologic H-2Ld epitopes. The Ag is attached to the cell membrane through a phosphatidyl-inositol linkage, characteristic of Qa-2 molecules. Both bulk cultured and cloned H-2Ld alloreactive CTL as well as H-2Ld restricted vesicular stomatitis virus-specific CTL lyse CRL-3A cells which express H-2Ld but show little or no lytic activity on cells which express the Ld/Q7d hybrid. These cells also fail to act as cold target competitors for alloreactive anti-H-2Ld CTL. However, cells expressing Ld/Q7d are not resistant to CTL mediated lysis because they can be killed in the presence of lectin. These data indicate that recognition of polymorphic class I CTL epitopes in the alpha-1 and alpha-2 domains are influenced by the structure of the carboxy-end of the molecule.
Mann
D W
DW
Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9048.
Stroynowski
I
I
Hood
L
L
Forman
J
J
D000818:Animals; D001667:Binding, Competitive; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000276:immunology*; D006183:H-2 Antigens / Q000235:genetics / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010716:Phosphatidylinositols; D011110:Polymorphism, Genetic; D051381:Rats; D013329:Structure-Activity Relationship; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D000939:Epitopes; D006183:H-2 Antigens; D015395:Histocompatibility Antigens Class I; D010716:Phosphatidylinositols; C032907:Q surface antigens