Role of autologous CD4+ T cell clones in human B non-Hodgkin's lymphoma: aborted activation and G1 blockade induced by cell-cell contact

Abstract

This article describes the study of the functional relationship between auto‐tumor‐reactive CD4+ T cell clones (TCC) and autologous malignant B cells. Four auto‐tumor‐reactive CD4+ TCC were derived from tumor‐infiltrating T lymphocytes (TIL‐T) from a freshly isolated human follicular lymphoma by the following technique: total CD4+ TIL‐T were negatively purified by an immunomagnetic procedure, then CD4+ TCC were obtained by limiting dilution in the presence of IL‐2 and autologous non‐irradiated follicular lymphoma cells as feeders. After expansion, these CD4+ TCC were co‐cultured with non‐irradiated autologous malignant B cells. All four TCC were activated by B lymphoma cells and proliferated, as assessed by CD25 expression and cell cycle analysis. Activation and proliferation of B lymphoma cells were studied in response to activated CD4+ T cells. Although all four TCC were able to induce B lymphoma cell activation (Ki‐67 antigen induction and CD40 up‐regulation), cells were subsequently blocked in G1 phase. Activation of B‐NHL cells was mediated by TCR‐HLA class II interaction, as shown by a blocking experiment using an anti‐CD4 monoclonal antibody (mAb). Since anti‐CD40 mAb with or without IL‐4 did not induce proliferation of B lymphoma cells in contrast to normal B cells, we suggest that the blockade in G1 phase is due to the presence of abnormalities in B lymphoma cells. This is the first evidence that autologous reactive CD4+ TCC can engage follicular lymphoma B cells to enter the cell cycle and induce an aborted activation stage.

Tumor cell dissemination in follicular lymphoma

“…[26][27][28] Therapeutical strategies targeting the interaction of FL cells with their follicular microenvironment might therefore represent attractive approaches to fight tumor progression.…”

Graphical Representation of a Generalized Linear Model-Based Statistical Test Estimating the Fit of the Single-Hit Poisson Model to Limiting Dilution Assays

“…Table II indicates the results of statistical analysis of the data and precursor frequency. In the real experiment conducted with TIL-T in one case of B cell lymphoma (9), the slope test z derived from the generalized linear log-log model did not reject the SHPM, and it was concluded that the SHPM adequately fits the observed data. In contrast, in the simulated experiment, conducted according to the STTPM, the statistics z clearly rejected the hypothesis that the data conformed to single-hit kinetics.…”

“…According to the Poisson law, the fraction of wells not containing a The first set of data represents a limiting dilution culture aimed at estimating the frequency of IL-2-responsive TIL-T in one case of low-grade, splenic marginal zone lymphoma. The method has been previously described (9). Briefly, total spleen cells were separated into purified TIL-T and purified malignant B cells by using an immunomagnetic procedure.…”

In Vivo and In Vitro Modulation of HLA-DM and HLA-DO Is Induced by B Lymphocyte Activation

“…The mAb D1.12, recognizing an epitope near the peptide binding groove on the DR␣ chain (29), was used to stimulate the B lymphocytes via HLA-DR (30,31). IL-4 and anti-CD40 mAb, a well-known combination for B lymphocyte activation and proliferation, were applied as well (32,33). Finally, cells were incubated with PMA, a potent B lymphocyte activator via modulation of PKC (34,35).…”