摘要:

Summary:The curative effect of allogeneic bone marrow transplantation (BMT) is in part due to an alloresponse of donor lymphocytes against recipient leukemia termed the graft versus leukemia (GvL) effect. To identify target antigens for the GvL response on leukemia cells, we looked for polymorphism of proteinase 3, a primary granule protein overexpressed in myeloid leukemias. The study was carried out in 10 patients with hematologic diseases and their HLA-identical marrow donors. By polymerase chain reaction (PCR) -single strand conformation polymorphism assay, followed by direct sequencing of the PCR products, we found seven DNA polymorphisms. One of them encodes for either an isoleucine or a valine at position 119 of the amino acid sequence. Peptides that span the polymorphic site, at amino acids 115-124, were shown to bind in vitro to the HLA-A2 molecule. We screened 23 HLA-A2 patients with myeloid leukemia and their HLA-identical donors for this polymorphism. No relapse was found in the group of 4 evaluable patients who possessed at least one allele absent in their donor, whereas 7 of the 15 remaining evaluable patients relapsed. These data support the possibility that T-cell responses to allelic differences of proteinase 3 could be used as a basis for designing leukemia-specific adoptive T-cell therapy in acute and chronic myeloid leukemias.

ISSN:1524-9557    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Summary:A combination of molecular genotyping and protein biochemistry methods was used to assess the HLA-A, -B, -C genotyping and expression of six tumor cell lines. Four cell lines had been previously HLA typed by conventional serologic methods. Two could not be typed by serology because deficient in the surface expression of HLA-A, -B, -C molecules. As shown herein, all the 25 alleles carried by the six tested cell lines were typed at the DNA level. In addition, discrepancies between the previous serologic and the present DNA typing results were detected in 9 of the 21 tested serologic specificities. Typing at the protein level by isoelectric focusing and allele-specific monoclonal antibodies confirmed the DNA typing data. Our results exemplify the limits of the serologic typing procedures and demonstrate that molecular methods are highly desirable to conduct functional experiments and identify HLA losses in neoplastic cells at single allele level.

ISSN:1524-9557    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Summary:The immunogenic potential of melanoma cells and their recognition by the host's cytotoxic cells depends on the presence and on the level of expression of human leukocyte antigen (HLA) class I antigens, costimulatory molecules and melanoma- associated antigens (MAA), on neoplastic cells. In this study, we demonstrate that the DNA hypomethylating agent 5-aza-2'-deoxycytidine (5-AZA-CdR), significantly (p<0.05) enhanced the constitutive expression of HLA class I antigens, HLAAl and -A2 alleles, and of the costimulatory molecules intercellular adhesion molecule- 1 and lymphocyte function-associated antigen-3, on a panel of 12 melanoma cells. This upregulation peaked at day 4, slowly decreased thereafter, and returned to baseline levels 32 days after the end of treatment. In addition, treatment with 5-AZACdR induced a persistent expression of MAGE-1 in Mel 275 melanoma cells; this was still detectable, by reverse transcriptase polymerase chain reaction, 60 days after the end of treatment. In contrast, 5-AZA-CdR did not affect the constitutive expression of the high molecular weight-MAA by the melanoma cells investigated. These observations, together with data obtained comparing the effect of 5-AZA-CdR with that of interferon-7, strongly suggest that 5-AZA-CdR may have prospective therapeutic implications in active and/or passive specific immunotherapy for human melanoma.

ISSN:1524-9557    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Summary:The expression of cytokine mRNAs in tumor tissue, normal mucosa, and peripheral blood mononuclear cells (PBMCs) was studied in 12 patients with colorectal cancer undergoing surgical resection, to characterize local immune conditions. mRNA transcripts for interleukin (IL)-1β, IL-2, IL-2-R(p55), IL-4, IL-5, IL-6, and IL-10 were detected using the reverse transcriptase-polymerase chain reaction (RTPCR) technique. IL-6 mRNA was expressed in tumor tissue in 83% of the cases but only in one case in normal mucosa (p<0.001); serum levels of IL-6 did not show any correlation with IL-6 mRNA; IL-1β transcripts were present in all tumor tissue samples; no IL-4 expression was detected; IL-2 mRNA was only present in two tumors; IL-2R(p55) mRNA was found in 58% of tumors but not in normal mucosae (p=0.005). The expression of IL-10 suggests that it does not play a central role in colorectal cancer immunosuppression, and cytokine expression in PBMCs indicates a different and independent activation. This study suggests a pattern of expression of inflammatory cytokines in the tumor microenvironment, probably produced by infiltrating immune cells. The absence of the specific immune-activating cytokines, IL-2 and IL-4, could indicate an impairment of the anticancer immune response; IL-2R results confirm the dysregulation of the IL-2/IL-2R activation pathway. These findings may lead to a better understanding of the role of cytokines and especially IL-6 at the tumor site and hence their importance in developing an effective immunotherapy.

ISSN:1524-9557    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Summary:We studied the effect of a streptococcal preparation, OK-432, on the cytotoxicity and the proliferation of lymphokine-activated killer (LAK) cells for use in adoptive immunotherapy. Peripheral blood mononuclear cells (PBMC) were derived from healthy donors and patients with malignant brain tumors. We divided PBMC into two groups; these cells then were stimulated with interleukin-2 in the presence or absence of OK-432. OK-432 was added only in the initial 3 days during the 3-week midterm culture period. Then, we compared OK-432-stimulated LAK (OK-LAK) cells with standard LAK (sLAK) cells in terms of their rate of proliferation and cytotoxicity. OK-LAK cells proliferated more rapidly than sLAK cells. The cytotoxicity of OKLAK cells increased, whereas that of sLAK cells decreased. We also investigated the phenotypic differences between these two types of LAK cells and found that, on day 21, the OK-LAK cells consisted mostly of CD3−CD56+NK cells, whereas the sLAK cells consisted mostly of CD3+CD56−T cells. The difference in their level of cytotoxic potential might be explained by the difference of predominant phenotype.

ISSN:1524-9557    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Summary:Phase I/II clinical trials using ricin A chain-containing immunotoxins (RTA-ITs) in <125 patients with lymphoma have established that vascular leak syndrome (VLS) is the dose-limiting toxicity. A similar side effect has also been described for other immunotoxins (ITs) and for cytokines, growth factors, antibodies, and chemotherapeutic agents. To better reproduce the conditions underlying vascular leak syndrome in patients treated with immunotoxins, human skin grafts were transplanted onto SCID mice and modifications in the graft were studied after systemic administration of a RTA-IT. Compared with mice receiving saline, an increase in wet/dry weight ratios of these grafts was observed in mice injected with RTA-IT. An increase in the permeability of the human blood vessels was also demonstrated by the extravasation of Carbon Black and the accumulation of Evans Blue dye in the graft. Taken together, these observations suggest that the RTA-IT can induce VLS-like manifestations. This model should facilitate the testing of potential inhibitors of VLS, which might reduce the toxicity of ITs and other therapeutic agents.

ISSN:1524-9557    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Summary:Several studies suggest that tumor necrosis factor-a (TNF) is able to overcome drug resistance in tumors. Whether TNF is able to do so in tumor cell lines that are drug resistant due to a mutation in the tumor suppressor gene p53 is unclear. Therefore, we studied the in vitro cytotoxic effects of TNF combined with various cytotoxic agents in a model consisting of a human ovarian cancer cell line containing endogenous wild-type p53 (wtp53) and sublines that were made drug resistant against various cytotoxic agents by transfection of several forms of mutated p53 (mtp53). Using the microculture tetrazolium assay, the cytotoxic effects of TNF alone, the cytotoxic agents VM-26, melphalan, cisplatin, vinblastine, paclitaxel, and mitoxantrone, plus the combined effects of 10 ng/ml TNF added 30 min before various concentrations of the cytotoxic agents were established. Compared with the control cell line (A2780/cmv), two cell lines transfected with mtp53 (A2780/m248 and A2780/ m273) showed increased resistance against several cytotoxic agents but also an enhanced sensitivity to TNF. Interaction of TNF with the cytotoxic drugs was additive in the drug-sensitive control cell line as well as in the drug-resistant sublines. However, because of the increased sensitivity of A2780/m248 to TNF at the dose used for the combinations, the combination of TNF with several cytotoxic drugs reduced the level of resistance in A2780/m248 compared with the control cell line A2780/cmv. In conclusion, this study shows that addition of TNF can ameliorate resistance to cytotoxic agents in a subline that is drug-resistant because of mutated p53. This reduction in resistance by TNF is not due to synergistic interaction, but to collateral sensitivity to TNF.

ISSN:1524-9557    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Summary:Seven ovarian and 33 breast high-risk stage II/III and stage IV cancer patients received high-dose chemotherapy followed by stem cell rescue. Thirty to 151 days after stem cell transplantation, the patients received their first immunotherapy treatment with Theratope STn-KLH cancer vaccine. Most patients developed increasing IgG anti-STn titers to a sustained peak after the fourth or fifth immunizations. Only one patient had elevated CA27.29 (MUC1 mucin) serum levels at trial entry. Five of the seven patients with preimmunotherapy elevated serum CA125 levels demonstrated decreasing CA125 levels during immunotherapy, consistent with an antitumor response. Evidence of STn antigen-specific T-cell proliferation was obtained from 17 of the 27 evaluable patients who received at least three immunotherapy treatments. Eleven of the 26 patients tested had evidence of an anti-STn TH, antigen-specific T-cell response as determined by interferon-7, but not interleukin (IL)-4, production. After immunization, lytic activity of peripheral blood lymphocytes (PBLs) tested against a lymphokine activated killer (LAK)-sensitive cell line, a natural killer (NK)- sensitive cell line, and an STn-expressing cancer cell line (OVCAR) increased significantly. In vitro IL-2 treatment of the PBLs after vaccination greatly enhanced killing of the STn+0 cancer cell line. Evidence of the development of OVCAR specific killing activity, over and above that seen due to LAK or NK killing, is presented. These studies provide the strongest evidence in humans of the development of an antitumor T-cell response after immunization with a cancer-associated carbohydrate antigen.

ISSN:1524-9557    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Summary:Previous in vitro studies of sarcoma and normal cell lines exposed to 41.8°C (x 60 min) demonstrated selective increased expression of members of the heat shock protein (HSP) family 70 on the cell surface of the sarcoma cells only. One implication of these data relates to the clinical application of targeting a stress-inducible, tumor-specific immune response. We therefore elected to measure immune response parameters (i.e., serum antibodies against HSP70i, 60, and 27) in six patients with sarcoma using a Western blot technique. These study patients received one to four successive 41.8°C whole-body hyperthermia (WBH) x 60-min treatments (given every 3 weeks). We also tested the serum of 10 untreated healthy control subjects for the same parameters. In all patients, baseline HSP antibody levels were detectable; in no case did WBH result in an increase in HSP antibodies. The serum of one patient with sarcoma demonstrated a strong nonfluctuating reaction against HSP27 before and after WBH that had no obvious correlation; this was not observed in the sera of the control subjects. This study suggests that WBH does not induce a B-cell response to HSP family 70 antigens; these data, however, do not exclude the possibility of NK cell activation due to HSP antigen presentation.

ISSN:1524-9557    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Summary:Interleukin-12 (IL-12) is a heterodimeric cytokine that enhances the cytolytic activity, proliferation, and interferon-γ (IFN-γ ) production by T lymphocytes and natural killer cells, and has significant antitumor activity in a variety of murine tumor models. The induction of interferon (IFN)-γ by IL-12 in tumor-bearing mice plays an important role in its antitumor activity. We therefore examined the effects of IL-12 on IFN-γ production by T cells derived from patients with renal cell carcinoma (RCC), including freshly isolated tumor infiltrating lymphocytes (T-TIL), matched peripheral blood T cells (T-PBL), and RCC-specific TIL lines. IL-12 alone induced IFN-γ secretion by T cells from normal individuals and appeared to act synergistically with either IL-2 or anti-CD3 antibody. In contrast, it failed to stimulate significant IFN-γ secretion by T-PBL and T-TIL from RCC patients. This unresponsive state in T-PBL appeared selective because IFN-γ was produced when cells were stimulated with either phytohemagglutinin or anti-CD3 antibody. Moreover, costimulation through the T-cell receptor (TCR)/CD3 complex or with IL-2 made T-PBL from RCC patients responsive to IL-12, possibly secondary to the upregulation of IL-12R (β chain). A selective loss of IL-12-dependent production of IFN-γ was also consistently observed in two of three established RCC-specific TIL lines. Although these cell lines did not respond to any concentration of IL-12, they did produce IFN-γ after ligation of the TCR/CD3 or stimulation with IL-2. IL-12 also acted either syngeristically or additively with IL-2, anti-CD3 antibody, or autologous tumor cells to induce IFN-γ production. The observed decreases in IFN-γ production in response to IL-12 may have a negative effect on the development of T-cell immunity. The clinical importance of these findings during in vivo administration of IL-12 remains to be determined.

ISSN:1524-9557    

出版商:OVID    

年代:1999

数据来源: OVID