Enrichment in tumor-reactive CD8+ T-lymphocytes by positive selection from the blood and lymph nodes of patients with head and neck cancer.

Abstract

To study antitumor functions of T-lymphocyte subpopulations in the blood [peripheral blood lymphocytes (PBLs)] and tumor-draining lymph nodes (LNs) of patients (n = 26) with squamous cell carcinoma of the head and neck (SCCHN), antibody-coated devices were used to positively select CD8+ or CD4+ cells. The mean percentage of CD8+ cells captured on antibody-coated flasks from PBLs was 92% and that captured from lymph node lymphocytes (LNLs) was 98%. The initial enrichment in CD4+ T-cells was comparable. CD8+ T-lymphocytes captured from PBLs proliferated as well as unseparated lymphocytes in both patients with SCCHN and normal donors, while captured CD4+ PBLs of the patients showed significantly lower expansion than those of normal volunteers. Unseparated LNLs proliferated as well as PBLs, but captured CD4+ or CD8+ LNLs failed to proliferate in the presence of interleukin 2 (100 units/ml) and phytohemagglutinin (5 micrograms/ml). The addition to captured LNL cultures of irradiated autologous or allogeneic feeder cells significantly improved expansion of CD8+ LNLs but not CD4+ LNLs. During 15-day culture of captured CD8+ PBLs or CD8+ LNLs in the presence of feeder cells, a significant (P less than 0.05) enrichment in CD8+ T-cells was maintained [94 +/- 5% (mean +/- SEM) or 99.5 +/- 0.1%, respectively, on day 15]. Capture of CD8+ LNLs and their expansion resulted in the outgrowth of CD8+CD11b- effectors which had no or little cytotoxicity against Daudi, low cytotoxicity against K562, and very high levels of cytotoxicity against 4 different natural killer cell-resistant SCCHN targets, as measured in 4-h 51Cr release assays. Such significant enrichment in SCCHN-restricted cytotoxicity could be obtained with LNLs from tumor-uninvolved LNs but not from tumor-involved LNs. Captured and cultured CD4+ LNLs had no preferential anti-SCCHN cytotoxicity. The addition of irradiated autologous tumor cells to captured CD8+ PBLs did not result in improved proliferation or antitumor function of the effector cells. Positive selection on antibody-coated flasks of CD8+ T-lymphocytes from tumor-uninvolved LNs of patients with SCCHN led to the enrichment in SCCHN-restricted but the major histocompatibility complex-unrestricted effector cells in 15-day cultures. Thus, CD8+ lymphocytes separated from tumor-draining LNs in patients with head and neck cancer contained cytolytic T-cell precursors capable of developing into effectors with preferential activity against SCCHN targets.