Human autologous tumor-specific T cells in malignant melanoma

Human abdominal aortic aneurysm (AAA): Evidence for an autoimmune antigen-driven disease

Abdominal aortic aneurism (AAA) is a complex immunological disease with a strong genetic component, and one of the ten leading causes of death of individuals 55-74 years old worldwide. Strong evidence has been accumulated suggesting that AAA is an autoimmune specific antigen-driven disease. Mononuclear cells infiltrating AAA lesions comprised of T and B lymphocytes and other cells expressing early-, intermediate- and late-activation antigens, and the presence of antigen-presenting cells have been documented, demonstrating an ongoing immune response. The three components of the trimolecular complex, T-cell receptor (TCR)/peptide (antigen)/HLA have been identified in AAA, and specifically: (i) clonal expansions of T-cell clones in AAA lesions; (ii) the association of AAA with particular HLA Class I and Class II; and (iii) self or nonself putative AAA-associated antigens. IgG autoantibodies recognizing proteins present in normal aortic tissue have been reported in patients with AAA. Molecular mimicry, defined as the sharing of antigenic epitopes between microorganisms (bacteria, viruses) and self antigens, maybe is responsible for T-cell responses and antibody production in AAA. Also, the frequency and the suppressor activity of CD4 + CD25 + FOXP3+ Tregs and the expression of FOXP3 transcripts and protein have been reported to be significantly impaired in AAA patients vs normal donors.

Clonally expanded alpha-chain T-cell receptor (TCR) transcripts are present in aneurysmal lesions of patients with Abdominal Aortic Aneurysm (AAA)

Abdominal aortic aneurysm (AAA) is a life-threatening immunological disease responsible for 1 to 2% of all deaths in 65 year old or older individuals. Although mononuclear cell infiltrates have been demonstrated in AAA lesions and autoimmunity may be responsible for the initiation and account for the propagation of the disease, the information available about the pathogenesis of AAA is limited. To examine whether AAA lesions from patients with AAA contain clonally expanded α-chain TCR transcripts, we amplified by the non-palindromic adaptor-PCR (NPA-PCR)/Vα-specific PCR and/or the Vα-specific PCR these α-chain TCR transcripts. The amplified transcripts were cloned and sequenced. Substantial proportions of identical α-chain TCR transcripts were identified in AAA lesions of 4 of 5 patients, demonstrating that clonally expanded T cells are present in these AAA lesions. These results were statistically significant by the bimodal distribution. Three of 5 of these patients were typed by DNA-based HLA-typing and all three expressed DRB1 alleles containing the DRβGln70 amino acid residue that has been demonstrated to be associated with AAA. All three patients exhibited clonally expanded T cells in AAA lesions. Four of the 5 patients with AAA who exhibited clonal expansions of α-chain TCR transcripts, also exhibited clonal expansions of β-chain TCR transcripts in AAA lesions, as we have demonstrated previously (J Immunol 192:4897, 2014). αβ TCR-expressing T cells infiltrating AAA lesions contain T-cell clones which have undergone proliferation and clonal expansion in vivo in response to as yet unidentified specific antigens that may be self or nonself. These results provide additional evidence supporting the hypothesis that AAA is a specific antigen-driven T-cell autoimmune disease.

Human breast tumor cells express IL-10 and IL-12p40 transcripts and proteins, but do not produce IL-12p70

IL-10 transcripts were expressed in 14/15 primary breast adenocarcinomas and in 5/8 established breast tumor lines. Immunohistochemistry and immunoprecipitation from lysates and supernatants revealed that established breast tumor lines produced IL-10 protein. Immunohistochemistry revealed that IL-10 is localized to tumor cells of primary breast adenocarcinomas and to occasional infiltrating MNC. Established breast tumor cell lines expressed IL-12p40 transcripts (6/8) and protein (4/7) and IL-12p35 transcripts (6/7). Using two sandwich ELISAs, specific, respectively, for IL-12p40 and IL-12p70 proteins, we demonstrated that established breast tumor cell lines produce IL-12p40 monomer/homodimer, but not IL-12p70. Positive staining for IL-12p70 in primary breast adenocarcinomas was found only in MNC infiltrating the tumor while tumor cells were negative. IL-12p40 homodimer/monomer inhibit as antagonists IL-12 or IL-23, although they may also act as agonists and positive regulators. Also, primary breast adenocarcinomas (15/15) and established breast tumor cell lines (6/8) expressed TGF-β1 transcripts. IL-10, IL-12p40 and TGF-β1 may inhibit substantially the anti-tumor immune response.

Adjuvant immunotherapy of patients with high-risk melanoma using vaccinia viral lysates of melanoma: results of a randomized trial

PURPOSE

Patients with high-risk melanoma treated by immunotherapy with vaccinia viral lysates were found in phase II studies to have improved survival compared with historical controls. We therefore elected to test this therapy in a phase III study.

PATIENTS AND METHODS

A prospective, randomized, multicenter trial to determine whether immunotherapy with a vaccine prepared from vaccinia melanoma cell lysates (VMCL) over a 2-year period after definitive surgery would improve relapse-free survival (RFS) and overall survival (OS) in patients with American Joint Committee on Cancer stage IIB and III melanoma compared with a control group treated only with surgery.

RESULTS

A total of 700 patients were randomized: 353 to VMCL and 347 to no immunotherapy. Seventy-seven percent had lymph node (LN) metastases and 66% had clinically detected LN metastases. Analysis on the basis of all eligible, randomized patients (n = 675) found, after a median follow-up period of 8 years, a median OS of 88 months in the control versus 151 months in the treated group (hazard ratio [HR], 0.81; 95% confidence interval [CI], 0.64 to 1.02; P =.068 by stratified univariate Cox analysis). At 5 and 10 years, survival rates for control and treated patients were 54.8% v 60.6% and 41% v 53.4%, respectively. Median RFS was 43 months in the control group compared with 83 months in the treated group (HR, 0.86; 95% CI, 0.7 to 1.07; P =.17). RFS at 5 years was 50.9% for the treated group and 46.8% for the control group. There were no selective benefits from the vaccine for particular subsets of patients.

CONCLUSION

Immunotherapy with VMCL was not associated with a statistically significant improvement in OS or RFS, with CIs not ruling out important gains from such treatment.

Studies of the mechanism of cytolysis by tumour-infiltrating lymphocytes

In order to determine the mechanism of tumour destruction by tumour-infiltrating lymphocytes (TIL), we examined the ability of both CD4+ and CD8+ effector TIL, and TIL clones, to manifest granzyme-mediated and Fas-mediated destruction of tumour targets. In many in vitro studies TIL have been shown to manifest anti-tumour reactivity, yet many tumours escape immunological destruction. To investigate the role of Fas expression and the concomitant sensitivity to the inducibility of apoptotic death, we derived TIL from four melanomas and one glioma. The glioma, and all but one of the melanomas, expressed Fas, but Fas-mediated apoptosis could only be detected if the targets were treated with cyclohexamide. The melanomas and the glioma all expressed detectable cytoplasmic Bcl-2 protein, known to exert anti-apoptotic activity. Lysis of tumours by CD8-enriched cultures and CD8+ clones was Ca2+-dependent and could not be modified by an anti-Fas MoAb. In CD4-enriched cultures or CD4+ clones with cytotoxic potential against tumour cells, cytotoxicity was also Ca2+-dependent. As Ca2+-dependent cytotoxicity is usually the result of secretion of perforin/granzyme-B, we investigated the presence of perforin in cytotoxic CD4+ clones and demonstrated the presence of granular deposits of this enzyme in some of the CD4+ clones. Although an anti-Fas MoAb did not block the lysis of melanoma targets by CD4+ clones, the examination of Fas-dependent targets demonstrated that these clones also had the potential to kill by the Fas/Fas ligand system. These data suggest that the predominant mechanism in tumour killing by TIL appears to be perforin-granzyme-dependent, and that the solid tumour cell lines we studied are less susceptible to Fas-mediated apoptosis. As non-apoptotic pathways may enhance tumour immunogenicity, exploitation of the perforin-granzyme-dependent cytotoxic T lymphocyte (CTL) pathways may be important for achieving successful anti-tumour responses.

In vivo accumulation of the same anti-melanoma T cell clone in two different metastatic sites

In a patient with progressing metastatic melanoma, we showed that the same autologous tumor-cytolytic CD8+ tumor infiltrating lymphocyte (TIL) clone accumulated in two separate metastatic sites. This clone, which represented three of eight independently derived clones from a tumor deposit on the skin of the abdomen, also represented two of eight clones derived from a skin lesion on the shoulder. This clone could be identified by its use of a unique TCRBV2-nD1n-J1S6 sequence, and could also be detected by single-stranded conformational polymorphism (SSCP) as the dominant TCRBV2-expressing clone among CD8+ TILs propagated from both shoulder and abdominal lesions. Using SSCP analysis, we also demonstrated that this clone was dominant in the fresh tumor tissue and in all TILs in which CD8+ were strongly represented, including several separate but parallel cultures. The SSCP pattern for this clone was not apparent among CD4+ TILs or CD8+ peripheral blood mononuclear cells. The SSCP analysis of the tumor tissue prior to in vitro culture is an indication that the selection for this anti-tumor cytotoxic T cell clone was a reflection of its in vivo accumulation. Thus, we provide evidence that melanomas are immunogenic and able to select for cytotoxic antitumor-specific TIL clones that are expanded in vivo and can circulate to accumulate in different tumor sites. However, because these clones were isolated from progressing tumor metastases, the accumulation of these specific cytotoxic T cells was not sufficient to contain tumor growth.

Expression of the co-stimulatory molecule CD40 on melanoma cells

We have previously shown that one of the co-factors required for generation of T-cell responses, B7.1, is variably expressed on melanoma cells. In the present studies we have examined the expression of another important co-factor in T-cell responses, viz., CD40, and investigated regulation of its expression and possible function(s). PCR analysis revealed mRNA for CD40 in all 18 cell lines established from metastatic melanoma and the majority of those from 6 primary melanoma. CD40 protein was detectable in approximately 50% of the cell lines by flow cytometry and in sections from only 2 of 20 melanoma. Expression of CD40 protein was increased in 2 of 3 cell lines with constitutive CD40 expression by interferon-gamma but not by granulocyte/macrophage colony-stimulating factor, interleukin-2 or tumor necrosis factor-alpha. Interaction of monoclonal antibody with CD40 on melanoma cells resulted in an increase in their cell division but did not increase expression of the costimulatory factor B7. Our results suggest that CD40 expression on melanoma may have important effects on their biology. The influence of CD40 expression on T-cell responses to melanoma remains to be investigated.

Immunotherapy for peritoneal ovarian carcinoma metastasis using ex vivo expanded tumor infiltrating lymphocytes

Surgery and chemotherapy have contributed to a modest overall survival in patients with epithelial ovarian carcinoma. It is therefore important to pursue novel therapy strategies for this disease that are different from conventional chemotherapy. Tumor infiltrating lymphocytes (TILs) from patients with ovarian carcinoma may represent an active immune response of the host directed against the tumor cells. These TILs can be expanded in vitro in low concentrations of recombinant interleukin-2 (rIL-2) by a few thousandfold. The resulting T-cell lines comprise CD3+CD4+TCR alpha beta + or CD3+CD8+TCR alpha beta + cells, or mixtures of both. These T-cell lines may exhibit either tumor-specific cytotoxicity against autologous tumor cells, or produce cytokines (interferon-gamma, tumor necrosis factor, and granulocyte stimulating factor) either in antigen-dependent (tumor-specific) or an antigen-independent manner. T-cell lines exhibiting primarily autologous tumor-specific cytotoxicity were developed from approximately 50% of the patients. Blocking experiments using appropriate monoclonal antibodies revealed that the CD3/TCR complex on the effector cells and the MHC class I antigens on the tumor cells were involved in the cytolytic process. We have developed a four-step method for the expansion of TILs to large numbers (1 x 10(10) to 1 x 10(11)) sufficient for clinical trials in patients with ovarian cancer. We have conducted a pilot clinical trial to examine the feasibility and clinical effects of intraperitoneal TILs and low-dose rIL-2 in patients with advanced ovarian carcinoma who were refractory to platinum-based chemotherapy. More recently, procedures have been developed for obtaining large numbers of purified CD8+ rIL-2-expanded TILs for the treatment of patients with ovarian carcinoma. The evolution of clinical trials and correlative studies necessary to develop an effective adoptive immunotherapy approach were discussed.

Generation of cytotoxic effector cells against human melanoma

Metastatic or tumor-draining lymph nodes from six of nine melanoma patients undergoing lymph node dissection for metastatic melanoma generated cytotoxic T cells against autologous melanoma when these lymph node cells were treated by in vitro sensitization and recombinant interleukin-2 (IL-2). During the initial lymphocyte culture (2-6 weeks), cross-reactivity with autologous tumor cells, K562 and Daudi cells was usually noted. Cold-target inhibition assay with K562 and Daudi showed K562/Daudi-associated antigens on melanoma cells. During the later phase of lymphocyte culture with repeated in vitro sensitization (over 6-10 weeks), cytotoxicity was noted against autologous and allogeneic melanoma cells but not against K562. Daudi cells or autologous fibroblasts. Repeated in vitro sensitization resulted in the selection of specific cytotoxic lymphocytes against melanoma. Cold-target inhibition assay with autologous and allogeneic melanoma cells revealed shared and individual antigens. Using blocking monoclonal antibodies, MHC-restricted killing was noted in the autologous system. Further, both the autologous and allogeneic systems could be mediated through adhesion molecules such as ICAM-1 and LFA-3 on melanoma cells and LFA-1 on T cells. This study suggests that a constellation of cytotoxic effector cells and melanoma-associated antigens may be pivotal in tumor killing. Thus, future adoptive immunotherapy should modulate and enhance this complex interaction.

Freshly isolated tumour-infiltrating T-lymphocytes have a high cytotoxic potential, as measured by their ability to induce apoptosis in the target cell

To test if freshly isolated tumour-infiltrating lymphocytes (TIL) can induce apoptosis in a target cell, we have combined two previously described methods. Because TIL predominantly are T-lymphocytes, we have applied a redirected approach. When the target cells that express anti-human-CD3 monoclonal antibodies in their membranes bind to the T cell receptor-associated CD3-complex, signals are generated, which activate T cell effector mechanisms. This approach circumvents problems with MHC-restriction and allows for functional testing of all T cells, irrespective of their clonal specificity. In order to assay for induction of DNA fragmentation, we have labelled the target cell nuclei with [3H]thymidine. Upon harvesting fragmented DNA are washed away. Electrophoretic analysis of the fragmented DNA demonstrated the characteristic 'ladder' pattern, consistent with apoptosis. This rapid and simple assay monitors the capacity of different T cells to induce apoptosis in the target cell. It depends on intercellular interactions and clearly discriminates between different T cell subsets. With this assay we demonstrate the functional integrity of the cytotoxic effector arm of freshly isolated TIL.

HLA-DQB1*0301 association with increased cutaneous melanoma risk

Susceptibility to a variety of malignancies has been linked to human leukocyte antigen (HLA) genes, including the HLA class II allele DQB1*0301. To determine whether melanoma risk is associated with HLA class II alleles, molecular oligotyping of HLA class II-DRB1, -DQA1 and -DQB1 genes was performed for 45 patients with melanoma. The DQB1*0301 allele was present in 56% of melanoma patients vs. 27% of 200 local Caucasian controls. This difference was highly significant (Bonferroni's-corrected chi-square p = 0.003, OR = 3.4). No other class II allele tested was present at significantly increased or decreased frequency in melanoma patients. Furthermore, presence of DQB1*0301 in melanoma patients was associated with advanced disease. Melanoma patients carrying the DQB1*0301 allele presented on average with thicker primary tumors (mean 3.7 mm vs. 1.8 mm, 2-tailed p = 0.02) and were more likely to present with regional or distant metastatic disease (stages III-IV, 44% vs. 5%, chi-square p = 0.003), compared to melanoma patients without DQB1*0301. Risk of melanoma incidence or progression may be influenced by DQB1*0301 or a closely linked gene.

Expression of the co-stimulatory molecule B7 on melanoma cells

The induction of T-cell responses against tumor cells is believed to depend on both recognition of antigen and receipt of co-stimulatory signals from interaction of ligands such as B7 with its receptors CD28 or CTLA-4 on T cells. In the present study the expression of B7 on cultured human melanoma cells was studied at the mRNA level by reverse PCR analysis and surface expression by flow cytometric analysis with monoclonal antibodies (MAbs). PCR analysis revealed mRNA for B7 in 3 of 6 (50%) cultured primary melanoma and 8 of 19 (42%) cultures of metastatic melanoma. Analysis of B7 expression by flow cytometry using the BB1 MAb revealed low levels of expression in 3 of 10 melanoma that had mRNA for B7. In 2 of the latter (but not 4 other PCR+ lines) expression could be increased by culture in GM-CSF, IL-2, IFN-gamma and IFN-alpha 2. Our results indicate that although mRNA for B7 is present in 40-50% of melanoma cell lines, expression at the protein level is at low or undetectable levels in the majority of the cell lines. Expression of B7 protein was also not detected in studies on tissue sections from 11 primary and 9 metastatic melanomas.

Characterization of fresh (uncultured) tumour-infiltrating lymphocytes (TIL) and TIL-derived T cell lines from patients with renal cell carcinoma

Fresh (uncultured) TIL from 12 untreated patients with primary renal cell carcinoma were prepared from tumour specimens by enzymatic digestion, and were characterized by immunofluorescence using MoAbs recognizing leucocyte differentiation antigens or particular V alpha or V beta segments of the T cell receptor (TCR). These fresh TIL comprised CD3+ (20-84%); CD4+ (3-15%); CD8+ (13-35%); alpha beta TCR+ (20-50%); gamma delta TCR+ (3-17%); CD16+ (1-18%) and CD56+ (3-10%) cells. Significant proportions of V alpha 2+, V beta 5.1+ and V beta 6+ cells were found in TIL of certain patients with renal cell carcinoma, suggesting that they comprised oligoclonal T cells. T cell lines were developed in low concentrations of rIL-2 (200 U/ml) from TIL from 11 patients with renal cell carcinoma, and were characterized by immunofluorescence and cell-mediated cytotoxicity. These T cell lines consisted primarily of CD3+ (51-94%); CD4+ (1-80%); CD8+ (0-84%); alpha beta TCR+ (65-87%); gamma delta TCR+ (0-25%); CD16+ (0-16%) and CD56+ (2-57%) cells. These T cell lines exhibited non-specific cytotoxicity against autologous and allogeneic renal tumour cells, with the exception of one T cell line that exhibited preferential cytotoxicity against autologous renal tumour cells. These results suggest that fresh TIL from patients with renal cell carcinoma contain significant proportions of oligoclonal T cells that may have accumulated at the tumour site as a result of a clonal expansion.

Management of recurrent cutaneous melanoma

Recurrent melanoma occurs in approximately one third of patients treated for cutaneous melanoma. Although the majority of recurrence occurs within the first few years of primary therapy, a significant number remains at risk beyond 10 years. With rising incidence of recurrent melanoma in Western countries, physicians will undoubtedly face the challenge of managing these patients with the limited therapeutic options currently available. Once melanoma has recurred, the overall prognosis is poor. Localized disease is best treated with complete resection, if indicated. Our existing armamentarium for systemic treatment falls short of altering the course of natural history of melanoma, but regional chemotherapy is an effective modality for in-transit disease and satellitosis. Translational research in molecular genetics and immunology will fuel new ideas for the design of rational strategies toward tumor eradication. Ongoing trials that use gene-modified melanoma cells have begun a new chapter in cancer therapeutics and lend us a closer examination of bench-top science at the bedside.

HIV-related tumors of the oral cavity

In HIV-infected patients with AIDS the most frequent malignancies are Kaposi's sarcoma and non-Hodgkin's lymphoma. In these patients, the natural history of these tumors is quite different from those of HIV-negative subjects. These tumors may present atypical clinical aspects, may be very aggressive, and the coexistence of immunosuppression and opportunistic infections may render their treatment more difficult. The aim of this article is to provide updated information on the epidemiology, pathogenesis, natural history, and management of tumors that develop in the oral cavity of patients with AIDS.

Direct evidence to support the immunosurveillance concept in a human regressive melanoma

The concept of immunosurveillance against cancer has been an extensively debated question over the last decades. Multiple indirect arguments have supported the view that the immune system may control, at least in certain cases, malignant cell growth while direct demonstration is still lacking in the human. In an attempt to address this issue, we have selected a study model, namely spontaneously regressive melanoma. In previous series of experiments, the variability of T cell receptors (TCRs) in the lymphocytes infiltrating a regressive tumor lesion was investigated. Results demonstrated that clonal T cell populations, precisely defined through their V-D-J junctional sequences, were amplified in situ. One clone was predominant, expressing the V beta 16 variable gene segment. A specific anti-V beta 16 TCR mAb was generated here to purify and functionally characterize the corresponding cells. A tumor-infiltrating lymphocyte-derived V beta 16+ T cell line was developed using this reagent. These in vitro cultured cells were found to express the in vivo predominant TCR sequence exclusively and to display an HLA-B14-restricted cytotoxic activity against the autologous tumor cells. Immunohistochemical experiments, performed with the anti-V beta 16 mAb, showed that the corresponding CTLs are present in the tumor area, some of them being closely opposed to the melanoma cells. Together, these studies demonstrate the existence of a local adaptive immune response clinically associated to tumor regression, thus strongly supporting the validity of the immunosurveillance concept in certain human tumors.

Large-scale expansion in interleukin-2 of tumor-infiltrating lymphocytes from patients with ovarian carcinoma for adoptive immunotherapy

Tumor infiltrating lymphocytes (TIL) from malignant ascites or solid tumor specimens obtained from patients with ovarian carcinoma were expanded to large numbers in vitro (10(10)-10(11)) by a four-step method using AIM V medium and low concentrations of recombinant interleukin-2 (rIL-2). The expansion procedure employed 24-well culture plates, T-flasks, polyolefin gas-permeable bags (PGPB), and an artificial capillary culture system (ACCS). The mean number of mononuclear leukocytes introduced into the 24-well plates was 16.5 +/- 4.2 x 10(6) cells. TIL from a total of 16 patients were expanded only through the first three steps of the process (24-well-plates, T-flasks, and PGPB) with an overall expansion of 255 +/- 99 fold and mean duration of 27.4 +/- 2.2 days. TIL from 9 of 16 patients were expanded further through the fourth step (ACCS) of the expansion method. The cumulative fold-expansion in nine patients was 8044 +/- 4807 (mean +/- SEM), the median was 2876 and the mean expansion time was 47.1 +/- 4.7 days. TIL from seven additional patients did not grow in rIL-2. Six of these 7 patients received chemotherapy at least four weeks before the specimens were collected. Two ACCS were used in parallel to facilitate expansion of TIL. Viable rIL-2-expanded TIL in the range of 1 x 10(10)-1 x 10(11) were recovered from the two ACCS, a number sufficient for adoptive immunotherapy of patients with ovarian carcinoma. The rIL-2-expanded TIL were predominantly CD3+ CD4+ CD8- alpha beta TCR+, although CD3+ CD4- CD8+ alpha beta TCR+ T cell lines were obtained from certain patients. An increase (43 +/- 8 vs 75 +/- 13; P = 0.05) in the proportion of CD4+ cells was observed over the duration of the four expansion steps. However, CD8+ TIL-derived T cells lines were also expanded in the ACCS. The four-step expansion method described here has several significant advantages over existing techniques. It requires substantially less personnel, equipment and space and the risk of contamination during expansion of the cultures is decreased. These results demonstrate that the four-step method described here can be effectively used for the large-scale expansion of ovarian TIL for the treatment of patients with ovarian carcinoma by adoptive immunotherapy.

Generation of cytotoxic immune responses during the progression of a rat glioma

Cytotoxic T lymphocytes specific for tumor-associated antigens are produced by exposing animals to tumor cells and stimulating lymphocytes from animals immunized in vitro with tumor cells and small amounts of interleukin-2 (IL-2). This study was designed to determine whether a fast-growing immunogenic avian sarcoma virus-induced glioma produces primed cytotoxic T lymphocyte precursors during its progression. Lymphocytes from intracerebral glioma-bearing rats generally failed to proliferate in vitro in response to immunization with tumor cells and IL-2 and, when proliferative responses were observed, the lymphocytes were not cytotoxic for glioma cells. However, when the same tumor was growing subcutaneously, lymphocytes proliferated and exhibited glioma-specific cytotoxicity when stimulated in vitro with autologous tumor cells and IL-2. Subcutaneous immunization of intracerebral glioma-bearing rats with tumor cells and adjuvant induced strong cytotoxic T lymphocyte responses. The results demonstrated that, while intracerebral tumor progression itself does not induce an anti-glioma immune response, immune responses to tumor-associated antigens may be induced by systemic immunization of tumor-bearing animals. The results suggest that the immunogenicity of brain tumors is masked by the immunologically privileged status of the brain, not by the induction of generalized immune suppression during tumor progression.

Detection of melanoma-reactive CD4+ HLA-class I-restricted cytotoxic T cell clones with long-term assay and pretreatment of targets with interferon-gamma

Twenty-five CD4+ cytotoxic T lymphocyte (CTL) clones were obtained from the peripheral blood or tumor tissues of melanoma patients undergoing active specific immunotherapy. Melanoma-reactive T cells were cloned by limiting dilution using either autologous or allogeneic melanoma cells to stimulate their proliferation. Sixteen of the clones reacted against autologous melanoma cells but not against the autologous lymphoblastoid cell line, which we defined as "melanoma-specific." Optimal demonstration of the lytic activity of CD4+ CTL required a 16-h incubation period and an effector:target cell ratio of 40:1. In addition, a 24-h pre-incubation of the target melanoma cells with 100 U interferon (IFN) gamma consistently augmented lysis by these CD4+ CTL, increasing it from a mean level of 20% to one of 52%. Lysis by 8 of the 11 melanoma-reactive CD4+ T cell clones was exclusively HLA-class-I-restricted, as judged by blocking with monoclonal antibodies (mAb). Five of these HLA class-I-restricted clones were reactive only with the autologous melanoma cells, while the other 3 clones were also reactive with allogeneic melanoma cells. In all cases, the T cells and melanoma targets shared at least one HLA class I allele, usually HLA-A2, HLA-C3 or HLA-B62. Interestingly, lysis by 2 of the 11 clones was inhibited by both anti-HLA-class-I or -HLA-class-II mAb, while lysis by 1 other clone was inhibited by neither. HLA class I molecules and several accessory molecules were maximally expressed by the melanoma target cells, both in terms of distribution and copy number before IFN gamma treatment. Thus, IFN gamma may have acted by increasing the expression of melanoma-associated epitopes as presented by HLA class I (or HLA class II) molecules. A proportion of human CD4+ CTL appeared to recognize melanoma-associated epitopes presented by the HLA class I molecule, although their lytic potency may be less than that of their CD8+ counterparts.

Expression of the neuroglandular antigen and analogues in melanoma. CD9 expression appears inversely related to metastatic potential of melanoma

Immunohistological methods were used to examine the relation between the metastatic potential of melanoma and expression of the neuroglandular antigen (CD63) and other members of this family of molecules, CD53, CD37, CD9 and the target of an anti-proliferative antibody (TAPA-I), as well as MHC-class-I and -II antigens. The criteria used to establish metastatic potential were their relation to thickness of the primary melanoma, and differences in expression between vertical and radial growth phases of primary melanoma and between primary and metastatic melanoma. Studies on basal-cell carcinoma (BCC) and squamous-cell carcinoma (SCC) were also included as controls for malignant skin cancers with low metastatic potential. Expression of CD9 and MHC-class-I antigen was found to be inversely related to thickness of the primary tumor, and CD9 was expressed predominantly on primary rather than on metastatic tumors. CD9 expression correlated with MHC-class-I expression on melanoma, and both were expressed on BCCs and SCCs having low metastatic potential, but not on compound nevi. CD63 and TAPA-I were expressed on nevi but not on SCC and BCC. Leu 13 is a molecule associated with TAPA-I in lymphomas, and was found to be expressed in sections from 5 out of 34 primary and 5 out of 21 metastatic melanoma. CD53 and CD37 were not detected on melanoma. Our results indicate that several members of the neuroglandular antigen are expressed in melanoma and that low expression of CD9 on primary melanomas might have prognostic significance with respect to the potential for metastasis.

Novel immunologic strategies in ovarian carcinoma

The purpose of our study was to develop new biologic systems for the treatment or diagnosis of patients with ovarian carcinoma through expansion of T-cell lines from the tumor-infiltrating lymphocytes of patients with ovarian carcinoma in low-dose recombinant interleukin-2 in sufficient numbers for treatment and human monoclonal antibodies that recognize cell-surface tumor-associated antigen determinants on ovarian carcinoma cells. Technologic advances in tumor immunology and new data presented in relation to ovarian carcinoma were used to develop T-cell lines for the treatment of advanced ovarian carcinoma patients. Logarithmic expansion of T-cell lines was performed in a hollow-fiber bioreactor, and a pilot clinical trial was initiated to treat ovarian carcinoma patients with intraperitoneal tumor-infiltrating lymphocytes plus low-dose recombinant interleukin-2. Human hybridomas were produced by fusion of regional lymph node B cells with a heteromyeloma cell line SPATZ 4. Two ovarian carcinoma patients have been treated with tumor-infiltrating lymphocytes expanded to 1 x 10(10) to 1 x 10(11) with manageable side effects and evidence of biologic activity. Human monoclonal antibodies have been developed that recognize tumor-associated antigen determinants. Recombinant interleukin-2-expanded tumor-infiltrating lymphocytes and human monoclonal antibodies recognize different molecular entities on tumor cells and act by different mechanisms. These approaches may be complementary to one another in future treatment strategies for ovarian carcinoma.

Specificity, T cell receptor diversity and activation requirements of CD4+ and CD8+ clones derived from human melanoma-infiltrating lymphocytes

To try to understand the functional significance of human melanoma-infiltrating lymphocytes (TIL), a clonal analysis of the specificity, T cell receptor (TcR) diversity and activation requirements of these lymphocytes isolated from four different tumors was carried out. Supporting the presence of in vivo primed tumor-specific T lymphocytes in these four tumors, a high frequency of the Cd8+ and CD4+ clones, obtained from the TIL cultured for a few days with recombinant interleukin (rIL)-2 and autologous tumor cells, exhibited a restricted lysis or proliferation in response to the autologous tumor cell line. In contrast, no tumor-specific clone was obtained from freshly extracted TIL, suggesting that the frequency of tumor-specific effectors remained low in these tumors. Only the CD8+ clones lysed the autologous tumor cells and their activity was major histocompatibility complex MHC class I restricted. Significant expansion of CD4+ and CD8+ tumor-specific clones required regular restimulation by autologous melanoma cells but also the addition of exogenous IL-2 and of Epstein-Barr virus-transformed B feeder cells. Five different tumor-specific clones, three CD8+ and two CD4+ clones were identified in a single tumor on the basis of their TcR gene configuration. Together, these data suggest that a spontaneous and diverse immune response, mediated by tumor-specific CD4+ as well as CD8+ T lymphocytes, arises in most MHC-bearing human melanomas but that antigen-MHC complex presentation by tumor cells does not, at least in vitro, allow a significant proliferation of these lymphocytes.

Gamma/delta T cell antigen receptors expressed on tumor-infiltrating lymphocytes from patients with solid tumors

The expression of gamma/delta T cell antigen receptors (TcR) in T cell lines or clones derived from tumor-infiltrating lymphocytes (TIL) from patients with solid tumors was investigated. gamma/delta TcR T cell lines were derived from TIL from patients with Wilms tumor, sarcoma or metastatic melanoma by stimulation with autologous tumor cells alone and recombinant interleukin 2 and they exhibited nonspecific cytotoxicity against autologous and allogeneic tumor cells, or cells of the K562 or the MEL21 tumor cell lines. Two T cell lines were derived from a patient with Wilms tumor. One of them expressed a non-disulfide-linked gamma/delta TcR using the 60-kDa gamma chain, whereas, the other expressed a disulfide-linked gamma/delta TcR. A T cell line was derived from a patient with sarcoma and expressed a disulfide-linked gamma/delta TcR, whereas, a T cell line derived from a patient with melanoma expressed a non-disulfide-linked gamma chain of 62 kDa. Several T cell clones were developed from patients with metastatic melanoma or Wilms tumor and expressed either disulfide- or non-disulfide-linked gamma/delta TcR. Northern analysis of RNA from certain of these clones revealed a full-length gamma chain transcript, whereas, the alpha or beta chain transcripts were either absent or truncated. These T cell clones exhibited nonspecific cytotoxicity. Both disulfide- and non-disulfide-linked TIL T cell lines and clones expressed the delta TCS1 determinant. gamma/delta TcR+ cells in freshly prepared TIL from these patients were present in low proportions (less than 5%) and their delta TCS1/delta 1 ratios were within the range observed in the peripheral blood of normal donors. These results demonstrate that both disulfide- and non-disulfide-linked gamma/delta TcR are expressed on T cell lines and clones derived from TIL from solid tumors. Non-disulfide-linked gamma/delta TcR using the 56-66-kDa gamma chain are frequently found on TIL-derived T cell lines and clones. These 56-66-kDa gamma chains are rarely expressed on T cell lines or clones derived from peripheral blood lymphocytes of normal donors.