Clonal analysis of a human lymphoblastoid cell line (B17) secreting antibody to N-acetyl-D-glucosamine.

In this paper we analyse the clonal composition of a human lymphoblastoid B-cell line secreting IgM/k antibody to N-acetyl-D-glucosamine, the immunodominant sugar of Group-A-streptococcal carbohydrate. Besides non-antibody secreting cells, the line consists of two clonotypes of antibody-secreting cells: B17 cells producing over 90% and F6 cells producing less than 10% of the antibody in the supernatant. The proportions of B17 and F6 cells in the cell line seem to be similar to the proportion of antibodies in the supernatant. F6 cells can be isolated by cloning and maintained as stable lines, whereas this is more difficult with B17 cells. The results suggest that upon establishment of the line, at least two N-acetyl-D-glucosamine-specific B cells were immortalized and coexist together as independent clonotypes. Although F6 cells seem to have a slight tissue culture advantage, they represent the minor clonotype in the B17 cell line.