Marco Ponte

Transforming growth factor-β-induced expression of CD94/NKG2A inhibitory receptors in human T lymphocytes

Different HLA class I‐specific killer inhibitory receptors (KIR) are expressed in vivo by a fraction of activated T cells, predominantly CD8+ , in which they may inhibit TCR‐mediated cell functions. In an attempt to identify mechanisms leading to KIR expression in T cells, we analyzed the effect of transforming growth factor‐β (TGF‐β) in T cells responding to bacterial superantigens in vitro. We show that TGF‐β induces the expression of CD94/NKG2A in cells responding to toxic shock syndrome toxin 1 or to other staphylococcal superantigens. Remarkably, maximal CD94 expression occurred at (low) TGF‐β concentrations which have no substantial effect on lymphocyte proliferation. Maximal CD94 expression occurred when TGF‐β was added shortly after the cells were placed in culture. No expression could be induced in CD94/NKG2A‐negative T cell clones. Although both CD4+ and CD8+ expressed CD94, the simultaneous expression of NKG2A was mostly confined to CD8+ cells. Monoclonal antibody‐mediated cross‐linking of CD94/NKG2A led to an impairment of T cell trigger ing via CD3, as determined in a redirected killing assay using the Fcγ receptor‐positive P815 murine target cells.

Detection of oligoclonal T lymphocytes in lymph nodes draining from advanced non-small-cell lung cancer

Despite the combined use of surgery and chemoradiotherapy, the poor prognosis of advanced non-smallcell lung cancer (NSCLC) requires the definition of new therapeutic approaches. The presence of T lymphocytes, with peculiar phenotypic, functional and molecular characteristics within the tumour, suggested the possible use of these cells, expanded in vitro, in protocols of adoptive immunotherapy. We have described how a population of oligoclonal T lymphocytes, derived from advanced NSCLC, can be expanded in vitro and has the capability of lysing autologous cancer cells. What is more important, we observed that patients with advanced NSCLC, treated with TIL expanded in vitro and recombinant interleukin-2, seemed to have a disease-free period longer than that of patients treated with conventional chemoradiotherapy. in an attempt to find new sources of specific lymphocytes for immunotherapy, we describe the analysis of the phenotypic, functional and molecular characteristics of T lymphocytes, derived from lymph nodes draining advanced NSCLC. In this paper we show that these cells, have restriction patterns of T cell receptor β chain similar to those detectable in the population of infiltrating T lymphocytes. This finding suggests that T cells derived from draining lymph nodes of advanced NSCLC have peculiar characteristics and can be a suitable source of effector cells for protocols of adoptive immunotherapy in lung cancer treatment.

Phenotypic, functional and molecular analysis of lymphocytes associated with bladder cancer

Abstract Bladder-washing-derived lymphocytes (BWDL) from 67 patients with bladder cancer were studied. The large majority of samples contained a pure population of T lymphocytes, whereas B and NK cells were absent. A comparative analysis of bladder lymphocytes and peripheral blood lymphocytes (PBL), collected in parallel, showed that BWDL significantly differed from PBL. In vitro cultures of bladder lymphocytes were attempted on 21 samples but in vitro expansion was only possible on six patients treated with bacillus Calmette-Guérin (BCG). This finding indicates that BWDL are characterized by a severe proliferative defect. Nevertheless, the addition of BCG on bladder lymphocytes expanded in vitro enhanced their proliferation, suggesting that this population is sensitized against BCG antigen(s). The analysis of T cell receptor restriction patterns showed that bladder lymphocytes from patients under BCG treatment were oligoclonal. A possible explanation for the efficiency of the immune response and good clinical outcome in patients treated with BCG could be found in the high homology between some BCG antigens and human heat-shock proteins, which are overexpressed in transformed cells.

Immunotherapy with the use of tumor-infiltrating lymphocytes and interleukin-2 as adjuvant treatment in stage III non-small-cell lung cancer: A pilot study

This study assesses the feasibility and toxicity of adoptive immunotherapy with tumor infiltrating lymphocytes and recombinant interleukin-2 in 29 patients who underwent resection for stage III non-small-cell lung cancer. In five patients cultures yielded no growth of tumor infiltrating lymphocytes. In the remaining 24 patients (stage IIIa, 14 cases; stage IIIb, 10 cases) tumor infiltrating lymphocytes were in vitro expanded from surgically obtained tissue samples, including samples from both the tumor and surrounding lung. A number of tumor infiltrating lymphocytes, ranging from 4 to 70 billion cells, were reinfused intravenously 4 to 6 weeks after operation. Interleukin-2 was administered subcutaneously at escalating does for 2 weeks and then at reduced doses for 2 to 3 months. Median survival was 14 months, and the 2-year survival was 40%. Three patients remain alive and disease-free at more than 2 years after operation. Two of these patients did not have complete resection at thoracotomy. Multivariate analysis showed no correlation between the factor of incomplete resection and survival. Intrathoracic recurrence without concomitant distant failure was documented in two patients only and none of the patients with incomplete resection (12 cases) had relapse within the thorax. The present experience demonstrates that adoptive immunotherapy may be applied with safety in patients operated on for stage III non-small-cell lung cancer and suggests that it can be useful, notably in patients with locally advanced disease.

Adoptive Immunotherapy With Tumor-Infiltrating Lymphocytes and Subcutaneous Recombinant Interleukin-2 Plus Interferon Alfa-2a for Melanoma Patients With Nonresectable Distant Disease: A Phase I/II Pilot Trial

Background: On the basis of our previous experience, we designed this study to determine the activity and toxicity of outpatient treatment with autologous tumor-infiltrating lymphocytes (TIL) together with intermediate-dose recombinant interleukin-2 (rIL-2) and low-dose recombinant interferon alfa-2a (rIFN-α2a), for patients with metastatic melanoma.Methods: Between April 1992 and October 1994, we processed 38 melanoma samples derived from 36 patients with metastases. Proliferative cultures of expanded lymphocytes (TIL) were infused only once into patients with metastatic melanoma. rIL-2 was administered subcutaneously for 1 month, starting on the day of TIL infusion, at an escalating dose of 6–18 × 106 IU/m2/day for the first week and at the maximum-tolerated dose for the subsequent 3 weeks and then, after a 15-day interval, for 1 week/month for 3 months. rIFN-α2a was administered subcutaneously at 3 × 106 IU three times each week until progression.Results: Of 38 melanoma samples, 19 (50%) resulted in proliferative cultures and were infused. The median number of expanded lymphocytes was 18 × 109 (range, 1–43 × 109), and the median period of culture was 52 days (range, 45–60). rIL-2 was administered at doses ranging between 6 and 18 × 106 IU/m2/day. Toxicity was mild or moderate, and no life-threatening side effects were encountered. Two of 19 treated patients experienced complete responses of their metastatic sites (soft tissue), 10 had stable disease, and 7 showed progressive disease. The response rate was 11% (95% confidence interval, 2–35%).Conclusions: Outpatient treatment with TIL plus rIL-2 and rIFN-α2a is feasible, although, within the context of the small sample size, the activity of the combination was no different from the reported activity of any of the components used alone.

HLA-class I-specific inhibitory receptors in human cytolytic T lymphocytes. Molecular characterization, distribution in lymphoid tissues and coexpression by individual T cells

A subset of cytolytic T lymphocytes has been shown to express receptors of the NK type (NKR) which can inhibit T cell cytotoxicity induced via the TCR-CD3 pathway. In this study, by the analysis of full length cDNA amplified from representative T cell clones, we show that NKR belonging either to the lg superfamily, including p58.1, p58.2, p70 and p140, or to the C-type lectin superfamily (CD94/NKG2A), display sequences which are identical to those of the corresponding NKR expressed by CD3-NK cells. Moreover, a fragment of cDNA encoding the NKG2A protein was consistently amplified from all CD94+ T cell clones analyzed. Since different NKR types can be expressed by T cells, we analyzed whether individual T cells could co-express more than one NKR. Analysis of either resting or activated (and cultured) T cell populations revealed that two or more NKR can be co-expressed by single T cells. Moreover, by the analysis of T cell clones, we show that co-expressed receptors are functional and can inhibit independently the TCR-induced cytolytic function. Finally, we investigated whether NKR+ T lymphocytes were also present in lymphoid tissues. No such cells were found in thymus or cord blood, thus further supporting the notion that they represent memory T cells. On the other hand, they were present in all the peripheral tissues analyzed including spleen, lymph nodes and tonsils.