Evaluation of the potential role of class II histocompatibility antigen HLA-DR in platelet/tumor cell interaction.
It has been reported that HLA-DR is a potent inducer of thrombin generation. Human colorectal cells (GEO, WiDr, DLD-1, and MIP) that lack the constitutive expression of HLA-DR cause platelet aggregation through a thrombin-dependent mechanism. Treatment with recombinant human gamma-interferon induced the expression of HLA-DR in the GEO, WiDr, and DLD-1 cells, whereas the MIP cell line remained HLA-DR negative. The concurrent analysis of tumor cell/platelet interaction after gamma-interferon treatment showed a decrease in platelet proaggregating activity of either the responsive GEO (highly expressing HLA-DR) or the unresponsive MIP (HLA-DR negative) cells. Furthermore, the DLD-1 (moderately expressing HLA-DR) cells showed an increase of proaggregating activity after gamma-interferon treatment, whereas WiDr (highly expressing HLA-DR) cells did not modify their activity. These results suggest a lack of a role of HLA-DR in the in vitro platelet proaggregating activity of human colorectal tumor cells.
Ferroni
P
P
Department of Experimental Medicine, University of Rome La Sapienza, Italy.
Guadagni
F
F
Spila
A
A
Martini
F
F
Gazzaniga
P P
PP
D000911:Antibodies, Monoclonal / Q000378:metabolism; D001792:Blood Platelets / Q000166:cytology* / Q000502:physiology*; D002450:Cell Communication / Q000502:physiology*; D002453:Cell Cycle / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000503:physiopathology*; D005069:Evaluation Studies as Topic; D006684:HLA-DR Antigens / Q000502:physiology*; D006801:Humans; D007124:Immunoenzyme Techniques; D010974:Platelet Aggregation / Q000502:physiology; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D006684:HLA-DR Antigens