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

As a means to increase the immunogenicity of tumor cells, we have developed a retroviral vector to transfect human B7, a molecule capable of delivering co-stimulatory signals to T cells. Three different tumors, a melanoma, an ovarian carcinoma and a myelomonocytic leukemia, were transfected with high efficiency. When compared for their capacity to stimulate allogeneic T cells, B7+ but not B7- tumor cells were able to stimulate strong proliferative and cytotoxic responses. The effector CTL generated recognised B7+ and B7- cells as well as untransfected tumor cells, indicating that B7 is required in the inductive but not the effector phase of the response. Remarkably, B7+ tumor cells were able to induce cytotoxic responses both by CD4-depleted and by CD8-purified T cells, demonstrating that expression of B7 is at the same time necessary and sufficient to induce a cytotoxic response in the absence of T-helper cells and accessory cells.
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PMID:T-helper- and accessory-cell-independent cytotoxic responses to human tumor cells transfected with a B7 retroviral vector. 751 23

Interleukin 15 (IL-15) is a novel cytokine that shares no homology with IL-2, but it requires the use of beta and gamma chains of the IL-2 receptor complex for binding and signaling. In vitro studies have shown induction of CTL and lymphokine-activated killer (LAK) cell activity in peripheral blood mononuclear cells (PBMCs) from normal donors by IL-15 against known tumor targets. The present study attempts to define the role of IL-15 in generating LAK activity from melanoma patient lymphocytes. PBMCs of patients newly diagnosed with metastatic melanoma were incubated with different doses of recombinant human IL-15 and tested against autologous tumor cells, LAK sensitive cell lines (i.e., FMEX and Daudi), as well as the natural killer-sensitive cell line K562, in a 15-h 51Cr release assay. The effect of IL-15 was found to be both time and dose dependent, with peak activity detected after 2 or 3 days of culture with 100 ng/ml of this cytokine. LAK and not CTL activity in patient PBMCs was detected by the inability of mAbs against CD4, CD8, and MHC class I to effectively block lysis of autologous tumor and FMEX melanoma cells. In addition, interaction via the CD18 adhesion molecule was shown to be critical in IL-15-induced LAK-mediated lysis of autologous tumor cells. Finally, incubation of patient PBMCs with IL-15 for 6 h resulted in the up-regulation of perforin mRNA transcription. These findings suggest that LAK activity can be generated from melanoma patient PBMCs in the presence of IL-15 to lyse autologous tumor cells in a non-MHC-restricted manner. This new cytokine may play an important role in antitumor immunity with a possible use for cancer immunotherapy.
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PMID:Interleukin 15 induction of lymphokine-activated killer cell function against autologous tumor cells in melanoma patient lymphocytes by a CD18-dependent, perforin-related mechanism. 758 40

There exists substantial evidence that the immune system plays an important role in the prevention and control of cancer. This evidence includes 1) the occasional clinical observation of spontaneous tumor regression, 2) the correlation of this phenomenon with the presence of tumor-infiltrating lymphocytes, and 3) the in vitro demonstration of the specificity of tumor-infiltrating lymphocytes for the autologous tumor. Because of the only weak immunogenicity of and the occurrence of active immunosuppression by the cancer, this response often does not suffice to combat the neoplasm successfully. One strategy for amplifying the anti-tumor immune response is vaccination of patients or experimental animals with cancer cells, the immunogenicity of which has been enhanced by the introduction of genes encoding immunostimulatory molecules. Several investigators have shown that transfection of certain types of cancer cells with the interleukin-2 gene reduces their tumorigenicity and that immunization with interleukin-2-transduced cancer cells protects animals from challenge with a tumorigenic dose of wild-type cancer cells. We have recently established a murine melanoma model (M-3) and have used it to elucidate the mechanism by which interleukin-2-transfected cancer cells can induce protective immunity. We will demonstrate the following: 1) that the mechanisms leading to the loss of tumorigenicity of interleukin-2-expressing cancer cells are somewhat different from those leading to the rejection of wild-type cancer cells in immunized animals, 2) that immunity resides within both CD4- and CD8-positive T cells, and 3) that host antigen-presenting cells are probably important in the induction of this protective anti-tumor immunity.
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PMID:Immunologic host defense in melanoma: delineation of effector mechanisms involved and of strategies for the augmentation of their efficacy. 761 88

Phenotypic characterization of peripheral blood lymphocytes was performed in patients with advanced metastatic cancer receiving low-dose recombinant interleukin-2 (rIL-2) and recombinant interferon-alpha (rIFN-alpha) as subcutaneous home therapy. A total of 31 patients with progressive metastatic renal cell carcinoma, malignant melanoma, colorectal cancer, B-cell lymphoma, and Hodgkin's disease, were evaluated. Patients were treated with a combination of low-dose subcutaneous rIL-2 and rIFN-alpha, consisting of a 2-day rIL-2 pulse at 9.0 million IU/m2 twice daily, followed by 6 weeks of combined low-dose rIL-2 at 1.8 million IU/m2 twice daily, 5 days per week, and rIFN-alpha at 5.0 million U/m2 3 times per week. This treatment regimen resulted in an overall significant (p < 0.002) increase in peripheral blood lymphocyte subsets expressing CD3, CD8, CD16, CD25, and CD56. Expansion of peripheral blood natural killer (NK) cells was correlated to treatment response. Thus, treatment-related increase in CD56-positive lymphocytes was 1.8-fold higher in complete or partial responders when compared to progressive disease patients (p = 0.0). Increase in NK cells upon low-dose rIL-2 and rIFN-alpha was associated with a significant expansion (p = 0.0) of peripheral blood eosinophils (r = 0.71). Patient pretreatment using rIL-2, rIL-2 and rIFN-alpha, or chemotherapy abrogated the treatment-induced induction of NK cells and IL-2 receptor- (CD25) positive T lymphocytes, respectively. Peripheral blood NK cells were significantly decreased (p < 0.05) in patients developing neutralizing antibodies specific to rIL-2.
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PMID:Low-dose interleukin-2 in combination with interferon-alpha effectively modulates biological response in vivo. 768 66

Interleukin-2 (IL-2)-dependent large granular lymphocytes (LGL) with a distinctive surface phenotype were generated from histologically normal duodenal biopsy tissues. Immunoperoxidase staining of the mucosa with an anti-CD56 monoclonal antibody revealed LGL localized in the lamina propria rather than in the epithelium. Light and electron microscopy demonstrated azurophilic and electron-dense cytoplasmic granules. Flow cytometry analysis revealed that these cells express CD45, CD56, CD2, CD7, CD11a, CD18, CD69 and the intermediate affinity (p70) IL-2 receptor (IL-2R) but not CD57, CD16, CD3, CD4, CD5, CD8, CD45RA, CD25, or the high affinity p55 IL-2R. The LGL proliferated when cultured in the presence of human rIL-2 but not in the presence of human rIL-4. Functional studies demonstrated that the LGL had strong cytotoxicity against natural killer (NK) target cells, K562, but not NK-resistant targets such as Colo 205, Melanoma and Epstein-Barr virus (EBV)-transformed B-cell lines. The LGL expressed genes for IL-5, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumour necrosis factor-alpha (TNF-alpha) and the corresponding cytokines were detected in culture supernatant. These results provide evidence for an important role of gut mucosal LGL in the induction and regulation of inflammation and immunity in the gut.
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PMID:Morphological, phenotypic and functional characteristics of a pure population of CD56+ CD16- CD3- large granular lymphocytes generated from human duodenal mucosa. 769 28

It has long been suggested that malignant melanomas, cutaneous as well as uveal, are responsive to human immune-mediated host defenses. We report here 5 consecutive cases of posterior choroidal melanomas which were treated with hyperthermia generated by high-intensity focused ultrasound. Patient immune function was monitored by determination of T-cell helper/suppressor (CD4/CD8) ratios immediately before and approximately 1 week following hyperthermia treatment. All 5 patients had normal total T-cell counts as measured by the pan-T-cell marker CD3. Two patients were noted to have inverted CD4/CD8 ratios (< 1:1) before hyperthermia. In both these cases, the ratio reverted to normal (> 1:1) 1 week following treatment. One patient whose CD4/CD8 ratio was not inverted was noted to have a further increase in his CD4 T cells relative to his CD8 (37% increase). Two patients with initially normal CD4/CD8 demonstrated no significant change following hyperthermia. It appears that ultrasonic hyperthermia may induce a systemic immunomodulatory effect in patients with posterior choroidal melanoma and inverted T-cell helper/suppressor resulting in a normalization of T-cell subset ratios.
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PMID:Immunomodulation in choroidal melanoma: reversal of inverted CD4/CD8 ratios following treatment with ultrasonic hyperthermia. 770 33

In epithelial cells integrins are segregated on discrete domains of the plasma membrane. Redistribution may also occur during migration or differentiation. However, little is known about the mechanisms that control such redistribution. Receptor internalization may be a part of one such mechanism. We developed a quantitative assay and measured internalization of two epithelial integrin heterodimers, alpha 6 beta 1 and alpha 6 beta 4, induced by cross-linking with specific antibodies. alpha 6 beta 1 is a receptor for EHS laminin, while alpha 6 beta 4 is a receptor for a component of the basement membrane. alpha 6 beta 4 plays an important role in the establishment of hemidesmosomes, and becomes redistributed on the epithelial cell surface when cells are in a migratory phase. We report that alpha 6 beta 4 is efficiently internalized in human keratinocytes. More than 25% of cell surface alpha 6 beta 4 was internalized at 30 minutes, after cross-linking with A9, an anti-beta 4 monoclonal antibody. alpha 6 beta 1 is also internalized, in melanoma and teratocarcinoma cells, with maximum values of 20% of total receptors expressed at the cell surface. No significant difference was observed between the alpha 6 isoforms A and B in these assays. To determine whether alpha 6 cytoplasmic domains could influence integrin endocytosis, we prepared chimeric constructs with the extracellular domain of a reporter protein (CD8), and the cytoplasmic domains of either alpha 6 A or alpha 6 B. Both alpha 6 cytoplasmic domains but not a control cytoplasmic domain promoted internalization of the chimeric proteins, after cross-linking with antibody. Internalization of alpha 6 integrins may have a role in redistributing these receptors at the cell surface. Furthermore, the cytoplasmic domains of alpha 6 may be involved in regulating integrin internalization.
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PMID:Quantitative measurement of alpha 6 beta 1 and alpha 6 beta 4 integrin internalization under cross-linking conditions: a possible role for alpha 6 cytoplasmic domains. 770 90

Autolymphocyte therapy (ALT) is adoptive cellular therapy of neoplastic disease using ex vivo activation of autologous (human) or syngeneic (murine) lymphocytes from tumor-bearing hosts (TBH) by low doses of anti-CD3 monoclonal antibody (MAb) and a mixture of previously prepared autologous cytokines (T3CS). Ex vivo activation by T3CS without tumor antigen results in expansion of CD44+ (memory) T cells. These memory T cells (ALT cells) mediate in vivo anti-tumor specificity and with cyclophosphamide (CY) are capable of curing metastatic disease in murine TBH. To determine whether CY could enhance the effectiveness of CD4+ or CD8+ subsets of ALT cells, C57BL/6J TBH with B16 melanoma or Lewis lung (3LL) carcinoma were treated with adoptive chemoimmunotherapy (ACIT) using CD4-depleted or CD8-depleted ALT cells and CY. ALT cells were derived from splenocytes of B16 or 3LL-TBH and activated ex vivo with T3CS. Depletion of CD4+ or CD8+ T cells was performed before or after activation with T3CS. B16-TBH or 3LL-TBH that received ACIT using CY with B16-derived or 3LL-derived CD8-depleted ALT cells, respectively, demonstrated cure of metastatic disease regardless of whether CD8+ T cells were depleted before or after T3CS activation. B16 or 3LL-TBH that received ACIT using CY with B16 or 3LL-derived CD4-depleted ALT cells also cured metastatic disease but only if CD4+ T cells were depleted after T3CS activation. Interleukin (IL)-2 added to pre-T3CS CD4-depleted ALT cells cultured with T3CS restored anti-tumor activity when combined with CY. TBH cured by ACIT using CY and ALT-cell subsets derived from syngeneic TBH with the identical tumor displayed tumor-specific immunity in rejecting a lethal challenge of identical but not reciprocal tumor. TBH given ACIT using CY and ALT-cell subsets derived from splenocytes of syngeneic TBH with reciprocal tumors rejected lethal challenges of both tumors. Tumor specificity measured by interferon (IFN)-gamma and 51Cr-release assays was demonstrated in pre- or post-T3CS/CD8-depleted, post-T3CS/CD4-depleted and pre-T3CS + IL-2/CD4-depleted ALT-cell subsets. Our data demonstrate that ACIT using CY combined with ex vivo T3CS-activated CD44+ memory T-cell subsets conveys long-term tumor-specific immunity.
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PMID:Adoptive transfer of ex vivo-activated memory T-cell subsets with cyclophosphamide provides effective tumor-specific chemoimmunotherapy of advanced metastatic murine melanoma and carcinoma. 775 64

Heat-stable antigen (HSA/J11d/possibly homologous to CD24), a cell adhesion molecule capable of providing a co-stimulatory signal for T cell proliferation, is expressed on B cells, activated T cells, monocytes, granulocytes, Langerhans cells and thymocytes. Recent studies have demonstrated that co-stimulatory signals provided by cell adhesion molecules such as B7-1 play an essential role in generation of an anti-tumor immune response. To examine whether the co-stimulatory signal provided by HSA can induce an anti-tumor immune response, we have transfected HSA cDNA into the murine melanoma cell line K1735M2, and examined the ability of this transfected cell line to induce tumor-specific T cell responses. The results demonstrate that spleen cells from mice immunized with HSA-transfected K1735M2 cells showed enhanced T cell proliferation in a mixed lymphocyte tumor reaction (MLTR) assay and also demonstrated a significant anti-tumor cytotoxicity to the parent tumor cell (K1735M2). This anti-tumor cytolytic activity could be abrogated by pretreatment of effector cells with anti-mouse CD8 monoclonal antibody and complement. Under similar conditions, spleen cells from C3H mice immunized with vector-transfected K1735M2 cells neither actively proliferate in an MLTR assay, nor did they exert significant cytolytic activity against the respective tumor cells. In summary, our study demonstrated that HSA can provide a co-stimulatory signal for the T cell immune response against tumor cells in a murine model.
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PMID:Expression of heat-stable antigen on tumor cells provides co-stimulation for tumor-specific T cell proliferation and cytotoxicity in mice. 777 19

We have previously described the generation of tumor-infiltrating lymphocyte (TIL) clones from renal cell cancer by solid-phase anti-CD3 antibody activation and expansion in 100 IU/ml IL-2 plus irradiated allogeneic B cells. These culture conditions did not select for a particular T cell subset. Using these culture conditions, we report here the generation of 66 CD4+ and 36 CD8+ TIL clones from five patients with melanoma. Eighty-five percent of the CD4+ TIL clones were not cytolytic (< 30% lysis, E:T 20:1) as determined by antibody-redirected lysis (ARL), whereas all CD8+ clones showed strong ARL activity (> 30% lysis). Clones were further tested for production of IL-2, IL-4, and IFN-gamma after activation for 48 hr by solid-phase anti-CD3. CD8+ clones produced significant amounts of IFN-gamma, little IL-2, and no IL-4. CD4+ clones were classified as Th0, Th1, or Th2, analogous to the classification of T helper cells in the mouse. Sixty-six percent existed as Th0, producing IL-2, IL-4, and IFN-gamma. Only 15% existed as Th1, producing IL-2 and IFN-gamma, and 19% as Th2, producing IL-4 but no IL-2 or IFN-gamma. In all cases, unstimulated clones or clones stimulated with the allogeneic B cell line did not produce detectable amounts of cytokines. Solid-phase anti-CD3 activation was compared to activation with autologous melanoma cells. Five of nine CD8+ clones produced low amounts of IL-2 (< 200 pg/ml/10(6) cells) in response to autologous tumor, but none of the CD8 clones produced IFN-gamma or IL-4. Also, 5/7 Th0 clones from one patient produced similar amounts of IL-2 after stimulation with anti-CD3 or autologous tumor. The other two clones produced only 10% or less of the amount produced in response to anti-CD3. No IL-4 or IFN-gamma could be detected in response to autologous tumor. In contrast, none of the 12 T helper clones from two other patients produced any cytokines after stimulation with autologous tumor cells. Together these data suggest that the T cell infiltrate in melanoma consists primarily of IL-2-producing Th0 cells, but few of those are triggered by autologous tumor cells.
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PMID:Classification of CD4+ T helper cell clones in human melanoma. 791 Oct 74


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