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)

The effects of Krestin (PSK) on the generation of lymphokine-activated killer (LAK) cells were examined in tumor-bearing mice. BALB/c mice were inoculated subcutaneously with methylcholanthrene-induced fibrosarcoma (Meth A) cells, and PSK was administered intraperitoneally every other day. The reduced LAK activity in tumor-bearing mice was restored by the administration of PSK. Since involvement of the humoral immunosuppressive factor in the impairment of LAK activity has been suggested, the effect of PSK on the impaired LAK activity in the presence of an immunosuppressive factor isolated from the ascites of X5563 (plasmacytoma)-inoculated mice was examined. The activity reduced by the immunosuppressive factor in an in vitro induction of LAK was restored by incubation with PSK. The antimetastatic effect of IL-2 was also augmented by its combined use with PSK. The data provide a rational basis for using PSK in combination with recombinant IL-2 in cancer immunotherapy.
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PMID:Effect of Krestin (PSK) on the induction of IL-2 activated killer cells. 161 82

Expansion of tumor infiltrating lymphocytes (TIL) in vitro is hampered by several factors, including a limited amount of lymphocytes obtained from different tumors, unknown target antigens and limited supply of antigen-presenting cells (APC) which are generally believed to be essential in the classical way of T cell stimulation and expansion. In approaching these difficulties, we have recently used surface-oxidized allogeneic PBL to stimulate the TIL periodically in the presence of a low dose of rIL-2 (200 IU/ml). TIL derived from 22 (out of 23) tumor specimens could be expanded with 20 -10(7) fold increases over 6-16 weeks to a sufficient amount of 10(9) -10(11) cells for adoptive immunotherapy. In contrast, only 2-100 fold increase were observed in six tumor specimens (out of 23) when 200 IU/ml rIL-2 was used only. The phenotypes, autologous tumor reactivity and cytolytic capability of TIL propagated with surface-oxidized stimulators were similar to those expanded in the presence of IL-2 alone. These data suggest that expanding TIL with surface-modified stimulator cells could be a useful alternative method to obtain a large amount of tumor specific cytolytic T cells for clinical immunotherapeutic use, irrespective of tumor-antigen stimulation and MHC restriction.
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PMID:Large scale expansion of human tumor infiltrating lymphocytes with surface-modified stimulator cells for adoptive immunotherapy. 162 31

The role of uncultured melanoma cells in the proliferation of autologous tumor-specific cytotoxic T lymphocytes (CTLs) was investigated. Uncultured autologous tumor cells by themselves induced modest, but significant, proliferation in 10 of 13 (77%) CTL clones and in only two of nine non-CTL clones. Uncultured allogenic melanoma cells mostly failed to induce CTL proliferation. Autologous tumor-induced CTL proliferation declined with increasing age of the culture. It did not correlate with IL-2 receptor-alpha expression or was not inhibited by addition of anti-IL-2 antibody to the culture. It was inhibited by pretreatment of tumor cells with anti-MHC class II, but not -MHC class I mAb. IL-2 alone was sufficient for the potent proliferation of five of nine CTL clones. In all these five CTL clones, autologous tumor cells suppressed IL-2-induced proliferation. The remaining four CTL clones, however, required both uncultured autologous melanoma cells and IL-2 for the proliferation. IL-4 or IL-6, in particular IL-6, facilitated IL-2-induced CTL proliferation, but not their cytotoxicity. In summary, uncultured melanoma cells by themselves induced modest levels of CTL proliferation in the context of MHC class II antigens, whereas they suppressed IL-2-induced CTL proliferation in more than half of the clones.
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PMID:Role of uncultured human melanoma cells in the proliferation of autologous tumor-specific cytotoxic T lymphocytes. 162 65

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

Expression of the human IL-6 gene in EBV-immortalized normal human B lymphocytes following retroviral-mediated transduction rendered these cells highly tumorigenic in athymic mice. The tumors were lymphomas composed of the originally inoculated human lymphoblastoid cells. Co-injection of IL-6 expressing EBV-immortalized cells with IL-6 nonexpressing control cells resulted in increased tumorigenicity of the IL-6 nonexpressing cells. The lymphoblastoid cells expressing IL-6 were indistinguishable from parental cell lines in morphology and in a variety of cell surface characteristics, and did not exhibit growth advantage over parental cell lines in vitro, such that increased tumorigenicity is unlikely to depend upon a direct oncogenic effect of IL-6 on the B cells. Rather, at high concentrations, IL-6 markedly inhibits human lymphoblastoid cell killing by IL-2-activated murine splenocytes in vitro, suggesting that IL-6-related tumorigenicity might depend upon IL-6 inhibiting cytotoxicity at the tumor site. Thus, production of IL-6 by tumor cells that results in natural killer cell dysfunctions illustrates a novel mechanism of tumor cell escape from immune surveillance.
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PMID:Impairment of natural killer functions by interleukin 6 increases lymphoblastoid cell tumorigenicity in athymic mice. 164 16

We have studied growth, function, and phenotype of purified NK and T cells in long-term cultures and compared these parameters to those of conventionally prepared interleukin-2-activated lymphocytes with killer cell activity (LAK). Enrichment of NK and T cells was achieved by Percoll density gradient. Growth was analyzed by cell counts and [3H]TdR uptake. Cytotoxicity and tumor-binding efficacy were assessed in a 3-h 51Cr and single cell agarose assay, respectively, against K-562, Daudi, human ovarian cell line Ovcar-3, and fresh leukemic blasts. We found that long-term proliferation and lytic activity were highest in NK-enriched and lowest in T-enriched cultures. Conventional LAK cultures generated medium cytotoxicity levels. Lytic activity declined within 3 weeks in cultures not enriched for NK cells, while NK-enriched cultures showed high levels of cytotoxicity up to 6 weeks. No change was found in binding activity within 3 weeks with the exception of T cell-enriched fraction. A number of changes in the phenotypic patterns was observed in IL-2 cultures; the CD56+/CD3-/+ and CD56+/CD8+ subset increased in most cultures, whereas the CD56-/CD3+ subset decreased over time. The highly enriched NK cell culture maintained its NK cell phenotype over 5-6 weeks. We also delineated the most cytotoxic lymphocyte subset in long-term IL-2 cultures by complement dependent cytotoxic assays and fluorescence-activated cell sorting (FACS). Lytic activity in conventional LAK as well as in T and NK cell-enriched IL-2 cultures was mediated primarily by CD56+, CD16+, CD3- NK cells. The clinical implication of these studies is discussed.
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PMID:Antitumor activity, growth, and phenotype of long-term IL-2 cultures of human NK and T lymphocytes. 165 70

Killer cell activity against Shope carcinoma cells was not detected in PBL nor in spleen cells from tumor-bearing B/J rabbits, but was induced by in vitro culture of these cells in the presence of IL-2 and X-irradiated carcinoma cells. HTLV-I-transformed killer cell lines were successfully obtained by the culturing of PBL from an HTLV-I-infected and tumor-bearing Chbb:HM rabbit. These killer cells included large cells with azurophilic granules in the cytoplasm and with a reniform nucleus, thus resembling large granular lymphocytes. The killer activity was similar against the Vx2K cell line from a random-bred rabbit and SCB cell lines from an B/J rabbit, suggesting the absence of MHC restriction.
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PMID:Killer cell lines against Shope carcinoma cells in rabbits. 165 41

Early studies with the Gross passage A leukemia virus demonstrated that retroviral infection suppresses cellular and humoral immune responses. In extensive studies of the feline leukemia (FeLV) virus, which can induce profound immunodeficiency disease, are generative anemia and lymphoid, myeloid and erythroid neoplasia, the immunosuppressive effects of this retrovirus could be attributed to the actions of the retroviral envelope protein p15E. We found that a highly conserved, synthetic 17 amino acid peptide synthesized by Cianciolo and co-workers that is homologous to the hydrophilic portion of the otherwise hydrophobic transmembrane envelope protein can suppress polyclonal activation of B-cells, impair production of gamma- and alpha-interferon, inhibit production of interleukin-2, inhibit expression of IL-2 receptors, and suppress responses of cytotoxic lymphocytes. In analyses with inactivated preparations of the human immunodeficiency virus, with Pahwa et al. we demonstrated that purified non-infectious retrovirus and also retroviral proteins, in particular gp120, appeared to produce some of the immunosuppressive properties of HIV, particularly suppression of B-cell activation in response to known B-cell stimulants irrespective of T-cell influence, suppression of T-helper cell functions essential to B-lymphocyte responsiveness, and impaired function of immunoglobulin-secreting cells. Other investigators have also reported strong immunosuppressive or immunostimulatory influences for components of the HIV retrovirus and also gp120 through yet poorly elucidated but certainly complex actions on both T- and B-lymphocyte-mediated immune functions.
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PMID:In vitro immunomodulation and in vivo immunotherapy of retrovirus-induced immunosuppression. 166 53

Peritumoral injection of recombinant human interleukin 1 beta (IL-1 beta) in mice transplanted subcutaneously with Friend erythroleukemia cells (FLC) resulted in a marked increase in survival time and inhibition of metastatic tumor growth in liver and spleen. In contract, IL-2 treatment alone did not significantly inhibit the development of FLC metastases. A synergistic antitumor effect was observed after combined IL-1/IL-2 therapy of these mice. The antitumor action of IL-1/IL-2 treatment was abolished or markedly reduced in mice treated with antibodies to CD4 or CD8 antigens, whereas antibodies to asialo-GM1 were ineffective. A clear-cut increase in the percentage of CD4+ cells was observed in the spleens of cytokine-treated mice on days 17 and 23. On day 23 of cytokine therapy, CD8+ cells were increased in both spleens and lymph nodes. On day 17, infiltrates of host-reactive cells (i.e., lymphocytes, granulocytes, and monocytes) were observed in both spleen and liver from FLC-injected mice treated with IL-1/IL-2, in association with tumor cells. On days 17 and 23, spleen cells and cells recovered from mesenteric lymph nodes of IL-1/IL-2-treated mice exerted a potent antitumor effect as determined by Winn assay experiments. This antitumor activity was abolished by preincubation of spleen cells with anti-CD8 antibody, but not by treatment with antibodies to asialo-GM1; antibodies to CD4 exerted only a slight effect. Combined IL-1/IL-2 therapy was more effective on established (i.e., 6-7-d) FLC tumors than on early (i.e., 1-d) tumor-transplanted mice. IL-1/IL-2 treatments were also highly effective in increasing survival time of mice from which the subcutaneous primary tumors were excised 7 d after FLC injection. These data indicate that in mice injected with FLC, the antitumor effects of IL-1/IL-2 are mediated by CD4+ and CD8+ cells (but not NK cells), and suggest that this combined cytokine treatment may be effective against established metastatic tumors.
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PMID:Combined interleukin 1/interleukin 2 therapy of mice injected with highly metastatic Friend leukemia cells: host antitumor mechanisms and marked effects on established metastases. 167 Oct 80

Tumor infiltrating lymphocytes (TIL) can be isolated from solid tumors and selectively expanded in long term culture with IL-2 and autologous irradiated tumor. Such long term cultured cells express anti-tumor activity in vitro, mediate the regression of established tumor in murine models of cancer, and have been used for the treatment of cancer in humans. We have characterized freshly isolated mouse Thy-1+ TIL populations, as well as long term TIL cultures, from several different C57BL/6 (B6) tumors. Freshly isolated Thy-1+ TIL include both CD4+ and CD8+ cells, as well as cells bearing NK markers. These cells are predominantly TCR alpha beta+, with a smaller population of TCR gamma delta+ cells. The TCR alpha beta+ cells expressed a broad distribution of V beta phenotypes that was statistically different from that expressed in normal B6 splenic Thy-1+ cells or CD8+ cells, presumably reflecting in vivo selection in the host anti-tumor response. NK cells are present in these tumors at a greater frequency than noted in splenic T cells. Cultured TIL populations rapidly became exclusively Thy-1+/CD8+/CD4- and TCR alpha beta+/gamma delta-. Individual long term TIL populations initially expressed multiple V beta products, but rapidly restricted their V beta expression, frequently expressing a single dominant V beta. The identity of this dominant V beta varied among different TIL lines, but the overall representation of V beta phenotypes in these cultures was statistically different from that seen in Thy-1+ or CD8+ splenocytes. No statistical difference was noted between lines derived from antigenically distinct tumors. The selection of tumor specific T cells in vitro is therefore not reflected in any simple predominance of V beta usage. The complexity of TCR usage in the anti-tumor response may result from the involvement of multiple alpha- and beta-chain regions in the response to a single antigenic determinant, or may reflect multiple antigenic determinants expressed on a single syngeneic tumor.
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PMID:Phenotypic characterization of murine tumor-infiltrating T lymphocytes. 167 40


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