ALTERATIONS IN EXPRESSION AND FUNCTION OF SIGNAL-TRANSDUCING PROTEINSIN TUMOR-ASSOCIATED T-CELLS AND NATURAL-KILLER-CELLS IN PATIENTS WITHOVARIAN-CARCINOMA

Tumor-associated lymphocytes (TALs) freshly isolated from patients wit h cancer usually manifest reduced proliferative and cytolytic function s. To determine whether alterations in signal transduction contribute to functional impairments seen in TALs, we purified populations of T a nd natural killer (NK) cells by negative selection from ascites of sev en patients with ovarian carcinoma. The average purity was 84 +/- 5% f or CD3(+) TALs and 77 +/- 10% for CD3(-)CD56(+)CD16(+) TALs. Expressio n of several signal transduction molecules, including the CD3-epsilon, CD3-zeta, and Fc epsilon RI-gamma chains, p56(lck) protein tyrosine k inase, and phospholipase C-gamma 1, was studied in these cells using W estern blotting, A marked decrease in expression of zeta and Fc epsilo n RI-gamma associated with CD3 or Fc gamma RIIIA was observed in T or NK cells obtained from TALs, as compared to T or NK cells purified fro m normal peripheral blood, Expression of CD3-epsilon, as assessed usin g flow cytometry, Western blotting, or ELISA was also reduced in purif ied TAL-T cells relative to that in normal peripheral blood T cells, S urface expression of CD3 on T cells and Fc gamma RIIIA on NK cells obt ained from TALs was significantly decreased in comparison to normal pe ripheral blood lymphocytes (PBLs): the mean fluorescence intensity of CD3 was 277 +/- 18 for TAL-T (n = 7) versus 349 +/- 13 for PBL-T (n = 9) and that of CD16 was 58 +/- 1 for TAL-NK (n = 7) versus 385 +/- 55 for PBL-NK (n = 23) cells, These observations suggest a defect in asse mbly of T cell receptor and Fc gamma RIIIA multicomponent transmembran e receptors, which are zeta and gamma dependent. In addition to altera tions in expression, the function of these receptors was also modified , since cross-linking of CD3 on TAL-T and CD16 on TAL-NK cells with th e respective monoclonal antibodies resulted in a pattern of protein ph osphorylation that was distinct from that observed in normal PBLs, Exp ression of tyrosine kinase p56(lck) and its kinase activity were also depressed, while expression of phospholipase C-gamma 1 appeared to be normal in most preparations of the TALs tested, In vitro proliferation of TAL-T in response to anti-CD3 monoclonal antibody and TAL-NK cells to interleukin 2 were significantly depressed as was the ability to p roduce IFN-gamma. In contrast, TAL-T cells were able to produce interl eukin 10 at levels similar to those secreted by normal PBLs, Thus, in TALs obtained from patients with advanced ovarian cancer, alterations in expression and activity of signaling molecules were associated with reduced cellular functions such as proliferation and production of ce rtain cytokines.