Factors influencing the establishment of tumour-infiltrating lymphocyte cultures from human breast carcinoma and colon carcinoma tissue

Expression of apoptotic regulatory molecules in renal cell carcinoma: elevated expression of Fas ligand

Renal cell carcinoma (RCC) is the most common renal neoplasm. Despite being infiltrated by tumour infiltrating lymphocytes (TIL), these TIL are unable to control tumour growth in vivo, suggesting that the cytotoxic capacity of TIL against RCC is impaired, or that the tumour cells are resistant to killing and therefore escape detection by the immune system. It is postulated that the expression of apoptotic regulatory molecules in RCC favours tumour cell survival. The present study has therefore determined the expression of Fas (APO-1/CD95), Fas ligand (Fas L) and bcl-2 in these tumours. The expression of Fas, Fas L and bcl-2 mRNA transcripts was determined in RCC, normal kidney and peripheral blood by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), following RNA extraction and cDNA synthesis from tissues and cell samples. Transcript levels were measured by densitometry after Southern blot hybridization of PCR products with internal radio-labelled oligonucleotide probes; a densitometry score was assigned to each hybridizing DNA band and expressed as a ratio of the glyceraldehyde-3-phosphate dehydrogenase content. In peripheral blood, the expression of Fas L and bcl-2 transcripts was similar between patients and normal healthy individuals; however, Fas transcript expression was significantly down-regulated in the patients' versus normal peripheral blood (P = 0.026). Most interestingly, significantly up-regulated Fas L expression was observed in RCC compared to normal kidney (P = 0.041). In contrast, bcl-2 transcripts were well represented in normal kidney but markedly decreased in RCC (P = 0.021). The expression of Fas transcripts in normal kidney and RCC was variable. These data demonstrate elevated expression of Fas L transcripts in RCC, but the functional relevance of this remains to be investigated.

Expression of cytokine mRNA transcripts in renal cell carcinoma

Renal cell carcinoma (RCC) is a solid tumour of the kidney and is the most common renal neoplasm. Despite the presence of tumour infiltrating lymphocytes (TIL) in RCC, these tumours continue to progress in vivo suggesting a poor host immune response to the tumour, and the suppression of TIL effector function. Cytokines are key molecules that modulate the function of T cells. The possibility is investigated that the local production of cytokines in RCC contributes to immunosuppression of TIL. The expression of pro-inflammatory (IFN-gamma/IL-2) and immunosuppressive (IL-10/TGF-beta) cytokine mRNA transcripts was determined in RCC, normal kidney and peripheral blood of RCC patients using a semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) with cytokine-specific primers. Following Southern blot hybridization of the PCR products with internal radiolabelled oligonucleotide probes, cytokine transcript levels were measured by densitometry and expressed relative to the glyceraldehyde-3-phosphate dehydrogenase densitometry score. With the exception of IL-10, there were no differences in expression of cytokine mRNA transcripts between the peripheral blood of patients and normal healthy individuals. It was found that TGF-beta transcripts were well represented in normal kidney and RCC. In contrast, the expression of IFN-gamma transcripts, while low in the majority of samples, was significantly increased in RCC when compared to normal kidney (P=0.05). The IL-2 and IL-10 transcripts showed a more variable expression in normal kidney and RCC, with no significant differences in expression between the sample groups. The data demonstrating pro-inflammatory and immunosuppressive cytokine expression in RCC do not support a prominent immunosuppressive cytokine profile in these tumours.

CD4+ T lymphocytes infiltrating human breast cancer recognise autologous tumor in an MHC-class-II restricted fashion

Tumor-infiltrating lymphocytes (TIL) were derived from primary breast tumors, metastatic lymph nodes and malignant pleural effusions from 34 patients with breast cancer. TIL were cultured for approximately 30 days and studied for phenotype, cytotoxicity, and the ability to secrete cytokines in response to autologous tumor stimulation. Tumor specimens were obtained from two different sites in 7 patients, resulting in 41 samples from which 38 TIL cultures were established. In addition to screening 38 bulk TIL cultures, TIL from 21 patients were separated into CD4+ and CD8+ subsets and extensively studied. Three CD4+ TIL were found specifically to secrete granulocyte macrophage-colony-stimulating factor and tumor necrosis factor alpha when stimulated by autologous tumor and not by a large panel of stimulators (24-34) consisting of autologous normal cells, allogeneic breast or melanoma tumors and EBV-B cells. This cytokine release was found to be MHC-class-II-restricted, as it was inhibited by the anti-HLA-DR antibody L243. These 3 patients' EBV-B cells, when pulsed with tumor lysates, were unable to act as antigen-presenting cells and induce cytokine secretion by their respective CD4+ TIL. These findings demonstrate that MHC-class-II-restricted CD4+ T cells recognising tumor-associated antigens can be detected in some breast cancer patients.

Isolation and expansion of lymphocytes from gastrointestinal tumour tissue

Adoptive cellular immunotherapy (ACI) with tumour-infiltrating lymphocytes (TIL) has met with some success in patients suffering from malignant melanoma. However, the success of this approach hinges on the successful isolation and in vitro expansion of TIL. Viable, IL-2 responsive TIL were obtained from only two of five gastrointestinal primary or 'non-lymph node' secondary gastrointestinal tumours. In contrast, proliferating TIL were successfully expanded from four out of five lymph node secondary deposits from gastrointestinal cancer patients, but these TIL were non-cytolytic. Conversely, proliferating lymphocytes were generated from six out of seven malignant effusions from gastrointestinal cancer patients in the late phase of their disease. Despite the presence of effective anti-tumour cytotoxic activity in one such culture, these lymphocytes failed to proliferate sufficiently for potential clinical use. Consequent upon these findings, we are sceptical that ACI using mononuclear cells infiltrating primary or secondary sites from patients with gastrointestinal cancer will be feasible.

Tumour-infiltrating lymphocytes in cervical carcinoma

Tumour-infiltrating lymphocytes from cervical carcinomas were cultivated in the presence of interleukin-2. The majority of bulk cultures were cytotoxic against K562, Mel 1 and Caski cells. CD8+ cells were the predominant subset in over 50% of cultures, with varying numbers of CD56+ and CD25+ cells. T cell clones were established from six tumour-infiltrating lymphocyte cultures and the majority exhibited non-MHC-restricted cytotoxicity. However, in one case cytotoxicity of several derived clones was limited to the autologous tumour and in another, to the autologous tumour and Caski cells. This study indicates that tumour-infiltrating lymphocytes can be amplified and cloned from cervical carcinoma biopsies in the presence of rIL2. Although the predominant cytolytic function is non-MHC-restricted, low autotumour cytotoxicity can be demonstrated at the clonal level. The nature of the antigen(s) recognised by T cells on autologous cervical carcinoma cells in unknown; the candidacy of human papillomavirus-related products requires investigation.