Major-histocompatibility-complex-class-II-positive cells and interleukin-2-dependent proliferation of immune T cells are required to reject carcinoma cells in the guinea pig

Abstract

Tumor immunity induced by bacillus Calmette-Guérin was studied in the line 10 hepatocellular carcinoma (line 10) in the strain-2 guinea pig. Line 10 immunity was investigated in vitro with a lymphocyte proliferation assay using line 10 tumor protein extracted with 3 M KCl and in vivo by adoptive transfer of line-10-immune spleen cells. Monoclonal antibodies against guinea pig leucocyte markers were used to block functional properties of the immune cells in order to determine which cell types or cell markers are involved in the immune response to the line 10 tumor. In vitro cells from the spleen, peripheral blood and regional lymph node of immune animals reacted with a proliferative response to line 10 protein. This antigen-specific response was caused by T cells and was regulated by major histocompatibility complex (MHC) class II molecules. In blocking experiments it was found that CT5 (anti-PanT), or MSgp4 [anti-(MHC class I antigen)] monoclonal antibodies did not block but sometimes stimulated the proliferative response. The effect of H159 (anti-PanT) was irregular, while H155 [anti-(T helper)], and 5C3 [anti-(IL-2 receptor)] monoclonal antibodies blocked the response almost completely. We studied the relevance of the results in vitro obtained and found that mAb 5C3 [anti-(IL-2 receptor)] inhibited the adoptive transfer of line 10 immunity, suggesting that the rejection of line 10 cells is caused by a mechanism that is interleukin-2 (IL-2)-dependent. Moreover, complement lysis of MHC-class-II-antigen-positive immune spleen cells inhibited completely the rejection of the line 10 tumor cell challenge in the adoptive-transfer experiments. In conclusion, our data show that MHC class II molecules or cells possessing these molecules are involved in immunity against line 10 tumor cells, as (a) monoclonal antibodies against MHC class II antigens inhibited the in vitro proliferative response of T cells to tumor antigens and (b) removal of MHC-class-II-positive immune spleen cells abrogated the antitumor effect in the adoptive-transfer experiments. Interleukin-2-dependent proliferation of immune T cells is required for the rejection of line 10 tumor cells.

Major histocompatibility complex class II antigen expression on leucocyte subpopulations in the draining lymph node and tumour in the early phase of bacillus-Calmette-Guérin-induced tumour regression

“…For the guinea-pig such a MHC class II antigen subtyping is not yet possible because of the lack of specific mAb. Recently we have shown that the cells expressing MHC class II antigen are needed for the recognition of the line 10 antigen in vitro and in vivo [37].…”

“…For detection of various leucocyte populations the following mAbs were used: CT5 and T188, anti-(pan T cell) [2,6,38]; CT6, anti-(T suppressor/cytoxic cell) [25,37,38], and CT7, anit-(T pan T cell) [1,25,38], but recently described as an antibody to T-helper/inducer cells. MSgp9 and 31D2 are mAbs reacting with all B cells and with IgM B cells, respectively [10,25].…”

Tumour rejection after adoptive transfer of line-10-immune spleen cells is mediated by two T cell subpopulations

“…The immunofluorescence was performed as described previously [27]. Pooled nucleated spleen cells (108 in 2 ml plain medium) of line-10-immune guinea pigs were transferred intracardially to naive recipients anaesthetized by an intramuscular injection of a mixture of Ketalar (20 mg/kg body weight, Parke Davis, Madrid, Spain.…”

“…O w i n g to the lack o f m A b s reacting with guinea pig T cell subpopulations, no particular T cell subpopulation m e d i a t i n g the rejection o f the line-10 t u m o u r has yet b e e n identified. W e recently s h o w e d in the line-10 t u m o u r m o d e l that the adoptive transfer o f line-10 i m m u n i t y is d e p e n d e n t on M H Cc l a s s -I I -a n t i g e n -p o s i t i v e cells and the p r e s e n c e of the interleukin-2 receptor [27]. The functional properties o f the T cell subpopulations stained by these m A b s h a v e b e e n described in a limited n u m b e r o f studies [1,4,16,22,23,28].…”

“…M H C class II antigen expression was previously shown to be important for the in vitro and in vivo response to line-10 protein and to line-10 cells respectively [27]. To study on which subpopulation of spleen cells the M H C class Il antigen expression was present, MHC-class-II-antigenpositive cells were removed after rosetting with Dynabeads and the remaining cells were studied with the rosetting assay or by flow cytofluorometry.…”