Auto-amor Reactive Cytotoxic T-cell Responses in B-Cell Non-Hodgkin's Lymphoma

Abstract

We have generated cytotoxic T-lymphocytes (CTLs) from the peripheral blood (PB) of eight B-cell non-Hodgkin's lymphoma (NHL) patients by in vitro coculture with autologous fresh tumor cells. Their functional activity was assessed in ⁵¹Cr release assay and was found to be MHC class I restricted. Ourss results indicate the presence of T-cells cytotoxic for autologous tumor cells in the PB of these patients but these were relatively small numbers in small lymphocytic lymphomas (SLLs). Treatment of fresh tumor cells with rlFN-γ and rTNF-α alone, or in combination significantly increased their susceptibility in 4/5 cases of SLLs, and a case of diffuse large cell lymphoma and Burkitt lymphoma (BL), while, B-cell lymphoma, rich in T-cells, did not show any appreciable increase. Fresh tumor cells were also analysed for MHC class I and ICAM-1 antigens by flow cytometry, in 5/8 cases before and after cytokine treatment. Significant upregulation of MHC class I antigens but with no detectable change in ICAM-I observed in a case of SLL and BL, correlated with enhanced susceptibility. These findings suggest the possible role of MHC class I antigens in the cytotoxic susceptibility of autologous tumor cells in B-cell NHL.

Key Words:

• Cytotoxic T-lymphocytes
• auto-tumor responses
• B-cell NHL
• MHC class I antigens
• cytokines
• rIFN-γ
• rTNF-α