Phenotypic analysis of nylon-wool-adherent suppressor cells that inhibit the effector process of tumor cell lysis by lymphokine-activated killer cells in patients with advanced gastric carcinoma

Abstract

The causes of down-regulation of cytotoxic immune responses in cancer patients have not been fully evaluated. We previously demonstrated that T-cell-growth-factor-activated peripheral blood lymphocytes (PBL) with the surface phenotype CD8+ CD11b-, from patients with widespread metastasis of gastric carcinoma, inhibited the effector process of lymphokine-activated-killer(LAK)-cell-mediated cytolysis. In this study, we examined suppressor cell activity in freshly prepared PBL from 18 patients with advanced gastric carcinoma, and 10 normal healthy individuals. The suppressor cell activity was assayed by recording whether or not PBL inhibited directly the effector process of LAK cell cytotoxicity. Most of the PBL suspensions from cancer patients showed that they contained a population of cells that can directly inhibit the effector phase of tumor cell lysis of the cytotoxic cells. To analyze further the PBL responsible for the suppression, the cells were passed over a nylon-wool column. Nylon-wool-adherent cells significantly augmented the suppression, while the cells passing through abrogated the suppressive effect. Most nylon-wool-adherent cells from 10 normal healthy controls did not inhibit the cytotoxic reaction. To determine further the suppressor-effector population in nylon-wool-adherent cells, negative-selection studies using CD8-, CD4- or CD11b-coated magnetic beads, and positive-selection studies using CD8- or CD4-coated magnetic beads were performed. Finally the results suggest that the suppressor-effector cells comprise at least two different surface phenotypes: CD8+ T and CD8-CD11b+ cells. The possible role of CD4+ T cells and HLA-DR+ LeuM3+ macrophages as suppressor cells was ruled out in nylon-wool-adherent cells. CD8+ T and possibly CD8-CD11b+ cells apparently suppressed the efferent limb of the antitumor immunity. The selective immune suppression mediated by these cells may partly be concerned with escape mechanisms of gastric carcinoma from the host immune surveillance system.

Expression of costimulatory molecules, B7-1 and B7-2 on human gastric carcinoma

“…Gastric carcinoma cell lines SC-1, SC-2, SC-3 and GCIY used for this study have been established and cultured continuously in our laboratory (Koyama et al 1987;Koyama 1994;Nozue et al 1995). The SC-1 cell line was from a poorly dierentiated adenocarcinoma and the other three carcinoma cell lines were derived from a signet-ring cell carcinoma.…”

“…The cells were then stained with a saturating concentration of primary mAb, CD86, followed by secondary antibody [phycoerythrin-conjugated goat anti-(mouse IgG) antibody; Biomeds, Foster City, Calif., USA] for 30 min on ice and washed twice. The cells were further treated with mouse IgG (Inter-cell Technologies Inc., Hopewell, N.J., USA) and stained with a saturating concentration of FITC-conjugated CD80 for 30 min on ice, as described previously (Koyama et al 1992;Koyama and Fukao 1994;Koyama 1997). As a negative control, an aliquot of the cells from each cell line and patient was stained with an irrelevant mAb of the same phenotype and secondary antibody.…”

Protective mechanisms of head and neck squamous cell carcinomas from immune assault

“…[33][34][35][36] In fact, some of the ways in which tumors induce host cells to inhibit immune responses are through the same soluble mediators and those by which tumors directly cause immune inhibition. 31,37 Although not all of the tumor-induced host immune suppressor mechanisms have been demonstrated and defined for head and neck cancers, it is reasonable to speculate that similar immune inhibitory cells are induced by HNSCC as by other solid malignancies.…”

Expression of epidermal growth factor receptor and CD44 splicing variants sharing exons 6 and 9 on gastric and esophageal carcinomas: a two-color flow-cytometric analysis

“…The cells were then stained with a saturating concentration of primary mAb: anti EGFR or CD44v9, followed by secondary antibody [phycoerythrin-conjugated goat anti-(mouse IgG) antibody (Biomeds, Foster City, Calif. USA] for 30 min on ice and washed twice. Mouse IgG (Inter-cell Technologies Inc., Hopewell, N.J. USA) was added to the cells, which were then stained with a saturating concentration of FITCconjugated CD80 or CD44v6 for 30 min on ice, as described previously (Koyama and Fukao 1994;Koyama 1997;Koyama et al 1992Koyama et al , 1998. As a negative control, an aliquot of the cells from each case was stained with an irrelevant mAb of the same phenotype and a secondary antibody.…”