indicating that the polymorphic region of the class I H-2 
molecule is responsible for inducing the immunologic response in 
this system (Fig. B) . 
WEEKS 
Figure B. The al and a2 domains of H-2K S are required for an 
anti-tumor response. C57B1/6 mice bearing the MCA 106 
fibrosarcoma were injected with H-2K S (■) n=5, the deletion 
mutant lacking al and a2 (0) n=3, or /9-galactosidase (□) n=3 
expression vectors. Results represent the average of each 
experimental group. 
II. Vector expression in human melanoma cells. 
The expression of HLA-B7 in vector II proposed for use in this 
study, has been confirmed in human melanoma cells. FACS analysis 
of primary transfectants and FACS sorted cells are indicated 
below. 
DoonmKindnt HM A Rpsparph VolllTTlft 15 
[4311 
