Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inflammatory mouse peritoneal macrophages were activated by IFN-gamma in synergy with IL-2 or Lipid A to mediate TNF production for autocrine generation of cytotoxic nitric oxide (NO) to kill P815 or L1210 tumor targets. It was determined that for IL-2, but not Lipid A, to effectively trigger activation of IFN-gamma-primed macrophages, the tumor targets must be also present for interaction with effector macrophages to mediate the production of TNF and NO. IFN-gamma- and IL-2-activated macrophages from syngeneic DBA/2 and allogeneic C3H mice had identical MHC-unrestricted requirements for interaction with DBA/2 mouse-derived P815 and L1210 targets to mediate production of TNF and NO for tumor cytotoxicity. To further define the mechanistic requirements for macrophage-tumor target interaction, IFN-gamma- and IL-2-activated macrophages were separated from P815 targets in culture by a semipermeable membrane. Under these conditions, both TNF and NO were produced by the macrophage, which indicated that the requirement for tumor target-macrophage interaction may be due to a soluble factor produced by the target rather than to direct physical contact. This was confirmed by experiments in which 24-h cell-free culture fluids, derived from either P815 or L1210 tumor targets, substituted for the intact tumor cells in the stimulation of TNF mRNA synthesis and secretion with NO generation of TNF mRNA synthesis and secretion with NO generation by IFN-gamma- and IL-2-activated C3H or DBA/2 macrophages. The activity in 24-h culture fluids derived from P815 and L1210 tumor targets was tentatively designated as tumor-derived recognition factor(s) (TDRF) since it was produced constitutively by the tumor targets and synergized with IFN-gamma and IL-2 to induce macrophage production of TNF and NO for death of the same targets. A variety of nontransformed human and mouse fibroblasts, mouse spleen lymphocytes, and two adherent mouse fibrosarcomas did not produce detectable TDRF activity, whereas two mouse T lymphomas, EL4 and EL4.IL-2, produced TDRF activity similar to L1210 mouse leukemia and P815 mastocytoma. The C3H/MCA, a TDRF-nonproducing mouse fibrosarcoma, was susceptible to cytotoxicity mediated by macrophages activated by IFN-gamma and Lipid A, but not by IL-2 triggering. Exogenous TDRF derived from L1210 targets reconstituted the cytotoxic activity for C3H/MCA MCA targets mediated by IFN-gamma- and IL-2-activated macrophages accompanied by the production of TNF and cytotoxic NO.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Tumor target-derived soluble factor synergizes with IFN-gamma and IL-2 to activate macrophages for tumor necrosis factor and nitric oxide production to mediate cytotoxicity of the same target. 151 76

Cytokines have recently appeared to be effective in the palliative therapy of neoplastic effusions. The present study was carried out to evaluate the efficacy and the tolerability of an intracavitary injection of IL-2 in patients with neoplastic effusion due to solid tumors. The study included 14 patients with cytologically positive effusion (pleura, 11; peritoneum, 2; pericardium, 1). Tumor histotypes were: mesothelioma, 5; non-small cell lung cancer, 3; breast cancer, 2; ovarian cancer, 2; cervix carcinoma, 1; unknown primary tumor, 1. The efficacy was evaluated according to the criteria of Paladine et al. (Cancer 38: 1903, 1976). An objective response was achieved in 10/14 (71%) patients (4 CR, 6 PR), with a median duration of 4 months (range, 2-8). No important toxicity was seen. This preliminary study showed that low dose IL-2 given intracavitarily is an effective and well-tolerated therapy in patients with neoplastic effusions.
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PMID:Intracavitary administration of interleukin-2 as palliative therapy for neoplastic effusions. 152 3

Adoptive immunotherapy in humans may be limited by the lack of autologous tumor cells to activate and expand tumor-specific T cells. Pharmacologic manipulation of protein kinase C (PKC) and intracellular calcium may substitute for tumor antigen and stimulate T cells for adoptive immunotherapy. In the present study, we evaluated the ability of the PKC activator Bryostatin 1 (B) plus the calcium ionophore ionomycin (I) to activate lymphocytes obtained from popliteal lymph nodes (DLN) draining an MCA-105 footpad tumor. The adoptive transfer of B/I-stimulated DLN cells eradicated MCA-105 pulmonary metastases. These lymphocytes do not require concomitant IL-2 administration to mediate regression of lung metastases. Three days after intrasplenic injection of tumor cells and splenectomy, mice were given iv injections of B/I-stimulated DLN cells. Adoptive immunotherapy with these cells induced regression of established liver metastases. In an intradermal tumor model, the adoptive transfer of B/I-stimulated MCA-105 DLN cells cured mice of MCA-105 intradermal (id) tumors, but did not induce regression of MCA-206 tumors. Mice cured of MCA-105 id tumors were protected against MCA-105, but not MCA-203, tumor challenge in the footpad 7 weeks after adoptive immunotherapy.
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PMID:Bryostatin 1-activated T cells can traffic and mediate tumor regression. 152 28

Tumor-infiltrating lymphocytes from mice bearing minor histoincompatible tumor cells in the anterior chamber (AC) or subconjunctival (SCon) space of the eye have been shown to contain large numbers of tumor-specific precursor cytotoxic T cells. Because SCon tumors eventually acquire directly cytotoxic, tumor-specific T cells and are rejected by their hosts and because AC tumors never acquire cytotoxic effector cells and are not rejected, we have examined tumor-infiltrating lymphocytes from both types of ocular tumors for the capacity to secrete lymphokines in response to in vitro stimulation with tumor cells. The results indicate that T "helper" cells were able to infiltrate both SCon and AC tumors. In the former, T cells capable of secreting IL-2 and IL-4 were found whereas in the latter only IL-2-secreting T cells were detected. These findings implicate a defect in local delivery of appropriate T cell help as the reason why AC tumors are not rejected. The failure of AC tumor-bearing mice to destroy their tumors correlates not only with defective delivery of local help but with a systemic inability to produce tumor-specific T cells that can secrete IL-2 and IL-4. Because these mice also generate down-regulatory T cells that suppress the expression of tumor-specific delayed hypersensitivity, they appear to have an immunologically mediated block in T helper cell differentiation which renders them unable to generate either T helper 1 or T helper 2 cells. This immunologic abnormality is discussed in terms of tumor rejection and the phenomenon of immunologic privilege.
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PMID:Local T helper cell signals by lymphocytes infiltrating intraocular tumors. 153 48

Tumor-infiltrating lymphocytes (TIL) were obtained from a mouse melanoma cell line (CL 62) transfected with the gene for the human melanoma Ag p97. TIL were cultured with anti-CD3 antibody and IL-2 for up to 38 days. Flow cytometry identified these TIL as Thy-1.2 + ve/CD4-ve/CD8 + ve cells. A heteroconjugated antibody 500A2 x 96.5, specific for both the CD3 Ag on TIL and the p97 Ag on CL 62 melanoma cells, was prepared using N-succinimidyl-3-(2-pyridyldithio)-propionate as a linking agent. TIL alone demonstrated low levels of cytotoxicity against autologous CL 62 tumor and also against the parental K1735 tumor and an allogeneic murine melanoma (B16). The addition of 500A2 x 96.5 heteroconjugated antibody enhanced TIL-mediated lysis of CL 62 tumor, but not of the K1735 or B16 tumors. This enhanced cytotoxicity was elicited at E:T ratios as low as 0.4:1, and in TIL cultured for 7 to 38 days. These results suggest that hetero-conjugated antibody may enhance the anti-tumor effect of TIL in vivo.
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PMID:Enhancement of in vitro tumor-infiltrating lymphocyte cytotoxicity by heteroconjugated antibodies. 153 18

Anti-CD3 antibody induced non-MHC-restricted cytolytic activity in murine spleen cells within 4 hr of incubation in vitro and within 8 hr in vivo after intraperitoneal injection. Interstitial lung leukocytes acquired the capacity to kill both NK-sensitive and -resistant targets within 24 hr after anti-CD3 injection. In vivo-stimulated spleen cells produced significantly more IL-2 and TNF than unstimulated cells. When these cells were restimulated with anti-CD3 in vitro, a potentiation of TNF production was seen. Interstitial lung leukocytes doubled their TNF production ex vivo after anti-CD3 injection, and the suppressed TNF production which was seen in lung cells from tumor-bearing animals was restored after anti-CD3 stimulation. The TNF production by alveolar macrophages was augmented 5-fold 48 hr after injection of antibody. Anti-CD3 antibody also induced significant accumulation of both TNF alpha and TNF beta mRNA in spleen and lung leukocytes. Pre-treatment with anti-TNF antibodies, both in vitro and in vivo, did not eliminate the cytolytic activation of lung and spleen cells. Our data indicate that anti-CD3 antibodies can induce rapid activation of both cytolytic activity and cytokine production in lung lymphocytes and macrophages.
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PMID:Anti-CD3 antibody-treated mice: in vivo induction of cytolytic activity and TNF production by lung leukocytes. 153 2

Peritumoral injection of human IL-2-activated natural killer cells into nude mice consistently induced regression of xenografts of human squamous cell carcinoma of the head and neck (SCCHN). To determine the mechanisms responsible for the tumor regression, the lymphoid cells infiltrating the tumor stroma at 24 to 48 h after adoptive immunotherapy were examined by in situ hybridization for the presence of mRNA for cytokines or IL-2R. Numerous lymphoid cells expressing cytokine or IL-2R genes were observed in these tumors, whereas the cultured IL-2-activated NK cells used for therapy were negative. Thus, it appeared that the transferred NK cells became activated in situ after coming into proximity with the tumor cells. To analyze this phenomenon, fresh or cultured human NK cells were coincubated in vitro with irradiated human SCCHN cell line, PCI-1, with or without the presence of IL-2. Expression of mRNA for IL-2R, perforin, and various cytokines was observed within 5 h. Contact with the tumor cells stimulated NK cells to proliferate, secrete IFN-gamma, TNF-alpha, and soluble IL-2R, up-regulate cell surface expression of IL2R p55 and p75 as well as CD16 Ag, and mediate higher levels of antitumor activity in 51Cr-release assays. In addition, supernatants of in vitro-activated NK cells significantly inhibited proliferation of SCCHN cell lines. By examining the effects of neutralizing mAb to various cytokines, this inhibitory activity was shown to be partially attributable to IFN-gamma. To determine the possible in vivo role of soluble factors produced by activated human NK cells, the supernatants (0.2 ml) or rIFN-gamma (10(5) U) were injected perilesionally each day for 2 wk into 3-day SCCHN established in immunosuppressed nude mice. These treatments caused significant (p less than 0.02) inhibition of tumor growth. The results of our studies indicate that human NK cells are strongly activated by SCCHN cells and that the consequent release of cytokines contribute to the regression of SCCHN growing in nude mice.
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PMID:Role of cytokines in the adoptive immunotherapy of an experimental model of human head and neck cancer by human IL-2-activated natural killer cells. 153 88

The generation of specific antitumor cytotoxic T-lymphocytes (CTL) via 2-fold immunization in vivo and subsequent cultivation without tumor cells (in monoculture) was previously described. The spleen cells from B10 mice bearing progressively growing MX-11 sarcoma suppressed the maturation of CTL specific to MX-11 but not to EL-4 lymphoma in monoculture. It was observed, that the suppression was not the result of the inhibitory effect of suppressor cells upon the IL-2 production, because suppression took place in the presence of the exogenous IL-2 in monoculture. Since the treatment of the spleen cells with MoAb against both L3T4 and Lyt2.2 antigens plus C' considerably decreased the suppressive activity, it was suggested, that two distinct subsets of T-lymphocytes were required for suppression. It might be possible, that the presence of anti-idiotype on the effector suppressors was the cause of the suppressive specificity in the absence of tumor antigens in vitro.
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PMID:[T-suppressors from tumor-bearing mice inhibit antitumor cytotoxic T-lymphocytes in monoculture]. 153 35

Although IL-2 infusion enhances cell-mediated cytotoxicity in patients with neoplastic disease, administration is paradoxically associated with a modest fall in total serum IgG and an increased risk of infection. We now show that the adverse effects of IL-2 infusion on the humoral immune system are substantial. Although IL-2 induces the B cell growth and differentiating factors IL-4 and IL-6, infusion abrogates primary antibody responses entirely and reduces secondary antibody responses 50-fold following antigen challenge. There is no evidence of the generation of cells with suppressive activity on B cells but IL-2 increases the ratio of circulating virgin:memory cells. These results may help to explain the increased rate of bacterial infection in patients receiving IL-2. As IL-2 plays a central role in the generation of an immune response, the finding that it is also sufficiently immunosuppressive to inhibit primary- and secondary-type antibody responses suggests that exploration of the underlying mechanisms may provide insights into immune system homeostasis and may offer new approaches to therapeutic immunosuppression.
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PMID:IL-2 infusion abrogates humoral immune responses in humans. 154 35

The observation that malignant cells express antigens that may be recognized by immunocytes and that immune effector mechanisms have the capability of destroying tumor cells has increased our appreciation of the biology of cancer and its relationship to immune function as well as offered new options for therapeutic intervention. Clinical trials are in progress to evaluate several different approaches to modifying the host's immune response against tumor. One approach is to administer agents that have direct activity against the malignancy. For example, antibody conjugates bring cytotoxic molecules of chemotherapy, radioisotopes, or toxins directly to the tumor. A second approach is to administer agents that modulate the host's own antitumor response such as IFN-alpha and IFN-gamma. Adoptive cellular immunotherapy aimed at isolating and expanding the host's own tumor-specific lymphocytes and inducing activation and proliferation with lymphokines such as IL-2 has shown encouraging results. Even though clinical data are still quite premature, it is reasonable to assume that in the future immunomodulation including the stimulation of immune effector mechanisms to eradicate tumor, the reconstitution of immune deficiency in diseases such as AIDS, the suppression of immune function to avoid graft rejection and GVHD, and the isolation and insertion of genes encoding tumor antigens into recombinant vectors to immunize the host to the tumor antigen will be commonly and successfully employed.
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PMID:The role of the immune system in the pathogenesis of cancer. 154 19


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