ISSN:
1365-3083
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Beta2-microglobulin (β2m) constitutes the common light chain of both the MHC-encoded HLA-ABC molecules and a group of structurally related glycoproteins recognized by antibodies of the first cluster of differentiation (CD1a, CD1b and CD1c). These CD1 antigens appear similar to murine T1 and Qa molecules in terms of structure and tissue distribution, although the question of inter-species homology is controversial. A further group of alloantigens expressed predominantly on T cells has been reported however, with immunogenetic characteristics more closely analogous to the murine T1/Qa system than the CD1 antigens, although their precise identity remains ill-defined. Having previously shown that malignant B cells may express membrane CD1c, we examined leukaemic B-cells corresponding to early lymphoblastic differentiation (null-and common acute lymphoblastic leukaemia) through to the terminal plasma cell stage for the expression of other non-HLA class I β2m -associated molecules. It was found that leukaemic B-cells at intermediate/late stages of differentiation, represented by non-Hodgkin's lymphoma (B-NHL) and‘hairy-cell’leukaemia (HCL), had significantly higher β2m: HLA-ABC ratios than did the cells from other types of B-cell malignancy. Although leukaemic B cells with a demonstrable non HLA-ABC- associated β2m component expressed detectable levels of CD1c. and insignificant levels of CD 1a and CD 1b, the antigen density was insufficient to account for the excess β2m. In vitro stimulation of leukaemic B cells by phorbol ester substantially increased the expression of HLA-ABC and CD1c, but also accentuated further the difference between the expression of these molecules and that of β2m. There was no detectable β2m other than that associated with HLA-ABC and CD1 on the surface of malignant T cells by contrast. Our findings strongly support the existence, at certain stages of leukaemic B-cell differentiation, of an additional β2m component(s) other than that associated with HLA-ABC and CD1.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-3083.1991.tb01520.x
