Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tumor-infiltrating lymphocytes (TILs) were isolated from a subcutaneous metastasis of melanoma and cytotoxic T-cell lymphocyte (CTL) lines were obtained by sensitizing in vitro four separate aliquots of TILs with autologous tumor cells and recombinant interleukin-2. All CTL lines were predominantly WT31+, CD3+, and CD8+ and displayed a preferential cytotoxic activity against the autologous tumor. T-cell receptor (TCR) composition was analyzed by using the polymerase chain reaction with 5' variable region (V alpha or V beta)-specific primers and 3' constant (C alpha or C beta) primers. The entire repertoire of the V alpha and V beta gene families tested was present in fresh TILs and in the CTL lines, although, in the latter, consistent quantitative variations in transcripts of several V alpha and V beta occurred. CTL clones that exhibited CD3-dependent and major histocompatibility complex-restricted killing of the autologous melanoma were isolated from the four TIL cultures. TCR analysis indicated that, independently from the culture of origin, only two combinations of V alpha and V beta gene families were present in the majority of these CTL clones. These V alpha and V beta gene families were not found in a panel of CTL clones that did not lyse the autologous tumor. This study indicates that recognition of melanoma antigens can strongly select for certain types of TCR-bearing T-lymphocytes.
 ...
PMID:Expansion of major histocompatibility complex-restricted antimelanoma cytotoxic T-cell lymphocyte clones with identical T-cell receptor from tumor-infiltrating lymphocytes. 133 45

Human melanoma cells are sensitive to the lytic activity of natural killer (NK) and lymphokine-activated killer (LAK) cells in vitro. The events resulting in tumour cell killing by lymphocytic effectors have not been completely clarified, and the same target cell determinants regulating responsiveness to immune cytolysis have not yet been identified. Indeed, changes in the differentiative status of leukemia cells as well as in the expression of major histocompatibility complex (MHC) antigens have been described to modulate sensitivity to cytotoxic effectors; moreover surface expression of adhesion factors or extracellular matrix proteins by the cancer cells can promote the activation of the cytolytic effectors and has been described to correlate with tumour cell sensitivity to cytolytic cells. We reasoned that treatment with differentiation inducers could modulate melanoma cell sensitivity to NK and LAK cells. The present study demonstrates that human melanoma GLL-19 cells, when treated with the phorbol diester phorbol 12-myristate 13-acetate (PMA) in vitro, undergo growth inhibition and neuron-like differentiation. Moreover, PMA treatment induces an evident inhibition of GLL-19 cell sensitivity to NK- and LAK-mediated cytotoxicity. GLL-19 cells express constitutively MHC class I antigens. PMA treatment, however, does not modify the expression of MHC class I and class II DR antigens in human melanoma GLL-19 cells. We have finally evaluated the effects of PMA on the expression at the cell surface of adhesion factors such as ICAM-1, and extracellular matrix proteins such as collagen IV, laminin and fibronectin; we have also studied the expression of the integrin vitronectin receptor, a membrane receptor for adhesive proteins. While adhesion factors and extracellular matrix proteins appear to play an important role in the interaction between immune effector and tumour target, it can be supposed that the modulation of such membrane-associated proteins or glycoproteins induces NK and LAK resistance in cancer cells. We indeed found that PMA treatment induced in GLL-19 a marked reduction of membrane expression of collagen IV and ICAM-1; moreover PMA reduced the cell membrane expression of the integrin vitronectin receptor. On the other hand, membrane expression of fibronectin and laminin was not affected by PMA. These data indicate that the acquisition of a NK- and LAK-resistant phenotype by GLL-19 cells occurs together with cell differentiation, down-regulation of membrane expression of collagen IV, ICAM-1 and vitronectin receptor, but in the absence of changes in MHC antigens.
 ...
PMID:Phorbol 12-myristate 13-acetate induces resistance of human melanoma cells to natural-killer- and lymphokine-activated-killer-mediated cytotoxicity. 137 27

Cytotoxic T lymphocytes (CTL), CD3+, alpha/beta T-cell-receptor-positive, are important effector cells with specific immunity in melanoma patients. The establishment and expansion in vitro of CTL of a specific phenotype to tumor cells strongly depends on the method of activation and sensitization with tumor cells. We generated CD3+ CTL lines to melanoma by co-culturing peripheral blood lymphocytes with autologous irradiated melanoma cells and repetitive stimulation with high-dose interleukin-4 in a "cocktail" culture medium. CTL lines were investigated for their specificity to kill autologous and allogeneic melanoma. Histocompatibility locus antigen (HLA) class I (A, B) molecules are important restrictive recognition antigens for CTL. Although these antigens are highly polymorphic, they can share a similar immunogenic molecular epitope(s) and can be immunologically cross-reactive. The CTL lines generated were found to kill not only autologous melanoma, but also allogeneic melanomas having class I HLA-A antigens shared or "cross-reactive" with autologous HLA-A. These CTL lines were poor killers of melanomas bearing non-shared or non-cross-reactive HLA-A. Cold-target inhibition assays demonstrated this CTL cross-reactivity to allogeneic melanoma specificity. Epstein-Barr-virus-transformed autologous and allogeneic B lymphoblastoid cell lines failed to block autologous melanoma killing, indicating that CTL were not recognizing major histocompatibility complex antigens, serum proteins or culture medium products as the primary target antigen. HLA-A2 was the major shared HLA-A antigen recognized by CTL lines on the melanoma lines studied. CTL lines also recognized shared HLA-A11 and A24 on allogeneic melanoma. There were no CTL lines showing restriction to HLA-B. These results suggest that common tumor-associated antigens are present on melanomas and are recognized in association with distinct HLA-A epitopes by CTL.
 ...
PMID:Cytotoxic T cell lines recognize autologous and allogeneic melanomas with shared or cross-reactive HLA-A. 137 43

The immunological and molecular mechanisms that govern T cell responses to human malignant tumours are just starting to be understood within a more complex framework of humoral, cellular and molecular interactions. The definition of multiple antigens simultaneously expressed on human melanoma, as detected with cytolytic T cells in immunoselection experiments, is a first step towards the molecular characterization of these antigens. Observations on the influence of expression of restriction elements of the major histocompatibility complex on the recognition of these tumour associated antigens have advanced our understanding of how the immune system responds to cancer cells in vivo. It is specificity that is tuning the immune system, not only in cancer. The molecular characterization of the first human cancer antigen recognized by CTL is now under way as outlined by Boon et al in this issue.
 ...
PMID:T cell responses to human malignant tumours. 142 25

We have studied the effects of interleukin-4 (IL-4) on the expansion, proliferation, phenotype, and antitumor activity of tumor-infiltrating lymphocytes (TIL) derived from human renal cell carcinoma. Cultures were obtained from three primary renal tumors and one group of tumor-invaded, regional lymph nodes. IL-4 induced a significant increase in lymphocyte expansion and proliferation, but the response was dependent on the concurrent dose of IL-2 in culture. Increased growth activity was only observed in those cultures receiving low doses (20 U/ml) of IL-2 (average increase of fold expansion of 6.5, P < 0.01) with no changes in growth activity in the high dose (1000 U/ml) cultures. The combination of low dose IL-2 and IL-4 (200 U/ml) promoted lymphocyte growth significantly better than high dose IL-2 alone, the current standard growth regimen for in vitro expansion of TIL. TIL grown in the presence of IL-4 significantly reduced the level of non-specific, non-major histocompatibility complex-restricted antitumor activity (P < 0.01 for allogeneic renal, nonrenal, and NK-sensitive K562 cells), while exhibiting no effect on the level of autologous killing. This is in contrast to previous findings of significant enhancement of autologous antitumor activity using IL-4 on tumor-specific, melanoma-derived TIL. We also evaluated the effects of irradiated autologous tumor stimulation (TIL:tumor ratio, 10:1) on TIL cultures. Addition of autologous tumor cells increased expansion and proliferation of all cultures regardless of concurrent lymphokines present in the culture media (average increase fold expansion of 2.21, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Regulatory effects of interleukin-4 on tumor-infiltrating lymphocytes derived from human renal cell carcinoma. 149 94

In situ immunophenotypic studies show that tumor infiltrating T lymphocytes from six of 11 fresh cutaneous primary melanomas tested contain T-cell receptor gamma delta expressing cells whereas those from 8 metastatic melanomas did not. In three cases these cells represent an unexpectedly high proportion of the lymphocytic infiltrate, ranging from 15 to 25%. This elevated percentage is maintained when tumor infiltrating lymphocytes are propagated in vitro for 2 or 3 weeks in the presence of recombinant interleukin 2 and autologous tumor cells. Functional studies reveal that gamma delta lines or clones developed from lymphocytes infiltrating primary melanoma display, in addition to their natural killer-like activity, a potent autologous tumor cell cytotoxic activity that does not seem to be restricted by major histocompatibility complex gene products.
 ...
PMID:TCR gamma delta bearing T lymphocytes infiltrating human primary cutaneous melanomas. 153 4

Interleukin-2 (IL-2) therapy generates killer cells with major histocompatibility complex (MHC)-unrestricted cytotoxicity against most tumors but not normal tissues. Cyclosporine A (CsA) has been reported to break tolerance to self and to induce killer cells with specificity against class II MHC (Ia) antigens both on the host and the tumor cells, resulting in a mild graft-versus-host disease (GVHD) in an autologous bone marrow transplantation (BMT) setting in the rat. We used these two agents in a syngeneic BMT model in a strain of mice that does not develop GVHD with CsA. Therapy with either agent alone was ineffective, whereas a combination of CsA plus IL-2 after BMT induced a potent graft-versus-tumor (GVT) effect against a melanoma and an acute myeloid leukemia. The antitumor effect could be adoptively transferred by infusing spleen cells harvested from mice treated with CsA plus IL-2 into secondary recipients that received chemoradiotherapy. The cytotoxicity of these cells was not influenced by treatment of tumor cells with gamma-interferon or Ia antibody. The cytotoxic effect was mediated by Thy 1+ and asialo GM 1+ cells. There was no GVHD either in the primary recipients of CsA and IL-2 or in those receiving the adoptively transferred spleen cells. Our findings show that combination therapy with CsA and IL-2 after syngeneic BMT induces a potent GVT effect in a non-MHC-restricted manner, and point to the existence of differences between the mechanisms of GVT and GVHD.
 ...
PMID:Synergism of interleukin-2 and cyclosporine A in induction of a graft-versus-tumor effect without graft-versus-host disease after syngeneic bone marrow transplantation. 161 Oct 84

In vivo experiments performed with NIH (nu/nu, bg/bg, xid/xid) triple immunodeficient (TD) mice revealed the striking ability of i.v. injected B16-F1 and B16-F10 murine melanoma cells to colonize not only the lungs but also the liver of TD mice. Subsequently, B16 melanoma cell cultures, which express very low levels of H-2Kb antigen, were cotransfected with plasmids pRSVneo, containing the neomycin resistance gene, and 6-2B1pMT, expressing the H-2Kb complentary DNA under the control of the metallothionein enhancer-promoter. Several neomycin-resistant clones were analyzed for H-2Kb and H-2Db expression by RNase protection and flow cytometry assays. All parental lines and transfected clones expressed normal levels of H-2Db mRNA, while only some of the transfected clones expressed easily detectable levels of H-2Kb mRNA. Moreover, in these clones H-2Kb expression could be enhanced in the presence of Zn2+, indicating that the metallothionein enhancer was functioning properly. Parental cells and transfected clones were injected i.v. in TD mice to assess the possible involvement of H-2Kb antigen in regulating the metastatic potential of B16 melanoma cells. We observed a remarkable correlation between expression of H-2Kb antigen and suppression of liver-specific metastases in TD mice. Identical results were obtained when we gave TD mice injections of mixed populations of transfectants expressing H-2Kb antigen, obtained by fluorescence-activated cell sorting. These experiments allowed us to rule out the possibility that the observed changes in metastatic potential were due to clonal variability among individual transfected clones. Taken together, the results of our in vivo studies with immunodeficient mice support the notion that specific major histocompatibility complex Class I molecules modulate the metastatic potential of malignant cells also by mechanisms which are independent of their well-established role in antigen presentation.
 ...
PMID:Expression of a transfected H-2Kb gene in B16 cells correlates with suppression of liver metastases in triple immunodeficient mice. 161 80

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.
 ...
PMID:Specificity, T cell receptor diversity and activation requirements of CD4+ and CD8+ clones derived from human melanoma-infiltrating lymphocytes. 162 24

Tumor-infiltrating lymphocytes from 120 samples of human cancers, including melanoma, renal cell carcinoma, breast cancer, sarcoma, and colon cancer, were examined. The percentage of lymphocytes recovered from the cancer varied widely; that of renal cell carcinoma was higher than that of breast or colon cancer (65% vs 45%), which was higher than that of melanomas or sarcomas (30% to 35%). The types of lymphocytes before and after interleukin 2 activation showed specific patterns. CD4+ helper T cells predominated in all tumors except melanomas, which had more CD8+ cytotoxic T cells. CD16+ natural killer cells were recovered in renal cell carcinoma and sarcomas. Three different cytotoxic lymphocytes were identified among interleukin 2-activated tumor-infiltrating lymphocytes: (1) CD3+ CD16- cytotoxic T lymphocytes with cytotoxicity restricted to autologous tumor cells in melanomas, (2) CD3-CD16+ natural killer cells with vigorous major histocompatibility complex-nonrestricted cytotoxicity in renal cell carcinoma, and (3) CD3+ CD16- T cells with modest levels of major histocompatibility complex-nonstricted cytotoxicity in all cancers except melanomas. Thus, there was considerable diversity of tumor-infiltrating lymphocytes among these histologically distinct tumors with respect to magnitude of lymphocyte infiltration, phenotypic expression, and functional capacity.
 ...
PMID:Patterns of human tumor-infiltrating lymphocytes in 120 human cancers. 168 43


1 2 3 4 5 6 7 8 9 10 Next >>