HLA-A, -B, -C genotyping and expression in human nonlymphoid tumor cell lines

A combination of molecular genotyping and protein biochemistry methods was used to assess the HLA-A, -B, -C genotyping and expression of six tumor cel l lines. Four cell lines had been previously HLA typed by conventional sero logic methods. Two could not be typed by serology because deficient in the surface expression of HLA-A, -B, -C molecules. As shown herein, all the 25 alleles carried by the six tested cell lines were typed at the DNA level. I n addition, discrepancies between the previous serologic and the present DN A typing results were detected in 9 of the 21 tested serologic specificitie s. Typing at the protein level by isoelectric focusing and allele-specific monoclonal antibodies confirmed the DNA typing data. Our results exemplify the limits of the serologic typing procedures and demonstrate that molecula r methods are highly desirable to conduct functional experiments and identi fy HLA losses in neoplastic cells at single allele level.