Lymphokine‐activated killer‐cell function of lymphocytes from peripheral blood, regional lymph nodes and tumor tissues of patients with oral cancer

Lymphokine‐activated killer (LAK) cells, generated from peripheral blood lymphocytes (PBL) from patients with oral cancer or oral leukoplakia and from healthy donors showed comparable lysis of 6 target tumor cell lines, including 3 derived from head and neck and oral cancers. The tumor burden of the host did not appear to influence the systemic LAK activity. LAK activity of lymphocytes infiltrating the tumor tissues (TIL) was also comparable to that of the PBL. Both TIL and PBL showed a parallel increase in proportion of HNK‐I++ and CD‐25+ CELLS upon activation with IL‐2. The lymph‐node lymphocytes (LNL) from metastatic (met) and non‐metastatic (non‐met) draining lymph nodes, however, showed reduced LAK activity and an increase in CD8 CELLS, in addition to CD25+ and HNK‐I+ cells, when cultured with IL‐2. When IL‐2‐activated LNL were co‐cultured with autologous PBL during IL‐2 activation of the latter, a strong suppressive effect was exerted by LNL In contrast, IL‐2‐activated PBL did not suppress autologous LAK generation in spite of an increase in CD8+ cells seen after activation with IL‐2. Frequency distribution of LAK precursors was significantly lower in LNL than in PBL from oral cancer patients. LAK precursor frequency in TIL was comparable to that of PBL. The results show that, in oral cancer, regional lymph nodes may not have adequate IL‐2‐inducible cytotoxic potential, due to a reduced number of LAK progenitors and possible activation of suppressor cells. Alternatively, TIL can be a potential source for LAK cell function.