Few molecules have been shown to confer cell motility, Although the motility-arresting properties of anti-CD9 monoclonal antibody (mAb) suggest the transmembrane 4 superfamily (TM4SF) member CD9 can induce a motorgenic signal, gene transfection studies have failed to confirm this hypothesis. We report here that ectopic expression of human CD9 (CD9h) and feline CD9 (CD9f) in the CD9-negative, poorly motile, human B cell line Raji dramatically enhances migration across fibronectin- and laminin-coated polycarbonate filters. Migration of Raji/CD9h and Raji/CD9f on either substrate was inhibited by the anti-CDS mAb 50H.19...

The reactive cell population in Hodgkin’s disease consists of predominantly CD4(+) helper T cells and lacks CD8(+) cytotoxic T cells and natural killer cells. This lack of a CD8(+) response is surprising in view of the expression of the Intent Epstein-Barr viral protein LMP by Reed-Sternberg cells in many cases of Hodgkin’s disease. Deficient HLA class I expression would be one possible mechanism to avoid a CD8(+) cytotoxic immune response. To test this possibility we studied the expression of HLA class I and II determinants on Reed-Sternberg cells...

Background. Epstein-Barr virus- (EBV) related DNA and RNA can be found in tissues involved with Hodgkin’s disease, specifically in the Reed-Sternberg cells. These cells also,express the membrane antigens LMP1 and LMP 2A and 2B. Studies in normal individuals indicate that cellular immunity against LMP2 was frequently mediated through human leukocyte antigen (HLA) A2, whereas responses to LMP1 appeared to be relatively infrequent. Assuming that LMP2-positive Reed-Sternberg cells would be sensitive to a CD8-positive cellular immune response, the hypothesis can be made that EBV-positive Hodgkin’s disease should be more...

One known postnatal change of CD45 expression is the decline of the CD45RA(high) CD45RO(low) T subsets and the reciprocal increase of the CD45RA(low) CD45RO(high) T subsets in the peripheral blood. Using a panel of monoclonal antibodies reactive with either protein or carbohydrate epitopes on the variable regions of CD45, we were able to detect more postnatal changes of CD45 expression. These changes are largely caused by modulation of the CD45 glycosylation, including: (1) lesser sialylation of the CD45RA region on T cells, and (2) differential sialylation of the...