Blood, Vol. 92 No. 7 (October 1), 1998:
pp. 2252-2259
Deficient Major Histocompatibility Complex Class II Antigen
Presentation in a Subset of Hodgkin's Disease Tumor Cells
Herbert Bosshart and
Ruth F. Jarrett
From the Leukemia Research Fund Virus Centre, University of Glasgow,
Glasgow, UK.
Hodgkin's disease is a common malignancy of the lymphoid system.
Although the scarce Hodgkin and Reed-Sternberg (HRS) tumor cells in
involved tissue synthesize major histocompatibility complex (MHC) class
II and costimulatory molecules such as CD40 or CD86, it is unclear
whether these tumor cells are operational antigen-presenting cells
(APC). We developed an immunofluorescence-based assay to determine the
number of MHC class II molecules present on the surface of single
living HRS cells. We found that in fresh Hodgkin's disease lymph node
biopsies, a subset of HRS cells express a substantial number of surface
MHC class II molecules that are occupied by MHC class II-associated
invariant chain peptides (CLIP), indicating deficient loading of MHC
class II molecules with antigenic peptides. Cultured Hodgkin's
disease-derived (HD) cell lines, however, were found to express few
MHC class II molecules carrying CLIP peptides on the cell surface and
were shown to generate sodium dodecyl sulphate (SDS)-stable MHC class
II 
dimers. In addition to showing deficient MHC class II antigen
presentation in a subset of HRS cells, our results show that the widely
used HD-cell lines are not ideal in vitro models for the disease. The
disruption of MHC class II-restricted antigen presentation in HRS
cells could represent a key mechanism by which these tumor cells escape
immune surveillance.
