Journal of immunotherapy : official journal of the Society for Biological Therapy最新文献

{"title":"Effects of recombinant human gamma-interferon on carcinoembryonic antigen expression of human colon cancer cells.","authors":"X W Yan,&nbsp;J Y Wong,&nbsp;J M Esteban,&nbsp;J A Kuhn,&nbsp;B G Beatty,&nbsp;J D Beatty,&nbsp;J E Shively","doi":"10.1097/00002371-199202000-00001","DOIUrl":"https://doi.org/10.1097/00002371-199202000-00001","url":null,"abstract":"<p><p>The effects of human recombinant gamma-interferon (gamma-IFN) on the levels of carcinoembryonic antigen (CEA) expression were investigated in vitro in three human colon adenocarcinoma cell lines (WiDr, HT29, and SW403). Subconfluent cultures were exposed continuously to IFN at concentrations of 1-1,000 antiviral units/ml for up to 6 consecutive days. IFN resulted in a significant increase in CEA levels when assayed by cellular enzyme-linked immunosorbent assay (ELISA), with higher concentrations and longer exposure times resulting in greater CEA enhancement. A three to five-fold enhancement of CEA was observed after 5-6 days of continuous exposures at concentrations of 100-1,000 antiviral units/ml. CEA levels returned to baseline over a 4-day period after discontinuation of IFN. Levels of IFN that resulted in CEA enhancement also resulted in cell growth inhibition, with a direct correlation observed. Flow cytometric studies, which evaluated changes in CEA membrane expression of only the viable cells remaining after IFN exposure, gave similar results to cellular ELISA. Quantitative CEA ELISA, which quantitated changes in total cellular CEA content, demonstrated greater increase in CEA than predicted by cellular ELISA. Continuous IFN exposures for 5-6 days at 1,000 U/ml led to a 96-, 26-, and 5-fold increase in total CEA for the WiDr, HT29, and SW403 cell lines, respectively. WiDr cells exposed to daily 6-h IFN pulses demonstrated intermediate increases in CEA compared with cells exposed continuously to IFN.(ABSTRACT TRUNCATED AT 250 WORDS)</p>","PeriodicalId":77209,"journal":{"name":"Journal of immunotherapy : official journal of the Society for Biological Therapy","volume":"11 2","pages":"77-84"},"PeriodicalIF":0.0,"publicationDate":"1992-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1097/00002371-199202000-00001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12738894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative in vitro studies of the potentiation of tumor necrosis factor (TNF)-alpha, TNF-beta, and TNF-SAM2 cytotoxicity by hyperthermia.","authors":"S P Tomasovic,&nbsp;S Lu,&nbsp;J Klostergaard","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Hyperthermia can strikingly enhance tumor necrosis factor-alpha (TNF-alpha) cytotoxicity in vitro and in vivo. Other forms of TNF may have tumor therapeutic applications and their interaction with hyperthermia should also be assessed. We have compared the effect of heat on the in vitro cytotoxic response of murine L929 and EMT-6 and human T24 tumor cells to three TNF forms; recombinant human TNF-alpha, TNF-beta (lymphotoxin), and TNF-SAM2. A neutral red assay was used to measure toxicity at 18-20 h after initiating the heat treatment. TNF treatment preceded heating by 0-4 h or followed it by 2 h. Heating was done at 39 or 40.5 degrees C for 24 h, 40.5 or 42 degrees C for 1 h, or 43 degrees C for 1-1.5 h. We found that both TNF-beta and TNF-SAM2 toxicities, like that of TNF-alpha, were markedly enhanced by hyperthermia. Neither EMT-6 nor T24 cells responded consistently to any of these TNFs at heat doses up to 1 h at 43 degrees C, but an increment of only 15 min more at 43 degrees C sensitized EMT-6 cells and 1.5 h at 43 degrees C resulted in extensive EMT-6 cell killing. The T24 cells remained resistant except for variable responses at the highest TNF and heat doses. If TNF treatment was begun immediately before or 2 h after beginning to heat the EMT-6 cells, sensitization was reduced or eliminated, respectively, for all three TNF forms relative to protocols in which TNF was added 1, 2, or 4 h before heating.(ABSTRACT TRUNCATED AT 250 WORDS)</p>","PeriodicalId":77209,"journal":{"name":"Journal of immunotherapy : official journal of the Society for Biological Therapy","volume":"11 2","pages":"85-92"},"PeriodicalIF":0.0,"publicationDate":"1992-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12738895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative in vitro studies of the potentiation of tumor necrosis factor (TNF)-alpha, TNF-beta, and TNF-SAM2 cytotoxicity by hyperthermia.","authors":"S. P. Tomasovic, S. Lu, J. Klostergaard","doi":"10.1097/00002371-199202000-00002","DOIUrl":"https://doi.org/10.1097/00002371-199202000-00002","url":null,"abstract":"Hyperthermia can strikingly enhance tumor necrosis factor-alpha (TNF-alpha) cytotoxicity in vitro and in vivo. Other forms of TNF may have tumor therapeutic applications and their interaction with hyperthermia should also be assessed. We have compared the effect of heat on the in vitro cytotoxic response of murine L929 and EMT-6 and human T24 tumor cells to three TNF forms; recombinant human TNF-alpha, TNF-beta (lymphotoxin), and TNF-SAM2. A neutral red assay was used to measure toxicity at 18-20 h after initiating the heat treatment. TNF treatment preceded heating by 0-4 h or followed it by 2 h. Heating was done at 39 or 40.5 degrees C for 24 h, 40.5 or 42 degrees C for 1 h, or 43 degrees C for 1-1.5 h. We found that both TNF-beta and TNF-SAM2 toxicities, like that of TNF-alpha, were markedly enhanced by hyperthermia. Neither EMT-6 nor T24 cells responded consistently to any of these TNFs at heat doses up to 1 h at 43 degrees C, but an increment of only 15 min more at 43 degrees C sensitized EMT-6 cells and 1.5 h at 43 degrees C resulted in extensive EMT-6 cell killing. The T24 cells remained resistant except for variable responses at the highest TNF and heat doses. If TNF treatment was begun immediately before or 2 h after beginning to heat the EMT-6 cells, sensitization was reduced or eliminated, respectively, for all three TNF forms relative to protocols in which TNF was added 1, 2, or 4 h before heating.(ABSTRACT TRUNCATED AT 250 WORDS)","PeriodicalId":77209,"journal":{"name":"Journal of immunotherapy : official journal of the Society for Biological Therapy","volume":"39 1","pages":"85-92"},"PeriodicalIF":0.0,"publicationDate":"1992-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78875018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of a human renal cell carcinoma specific cytotoxic CD8+ T cell line.","authors":"J H Finke,&nbsp;P Rayman,&nbsp;M Edinger,&nbsp;R R Tubbs,&nbsp;J Stanley,&nbsp;E Klein,&nbsp;R Bukowski","doi":"10.1097/00002371-199201000-00001","DOIUrl":"https://doi.org/10.1097/00002371-199201000-00001","url":null,"abstract":"Human renal cell carcinoma (RCC) is one of the tumors most sensitive to immunotherapy and in that regard it is similar to malignant melanoma. Clinical studies reporting responses to therapy suggested that a host immune response may be involved in the antitumor activity induced by immunotherapy in these tumors. Although detection of a specific T cell response to melanoma has been well documented, this has not been the case for RCC. The lytic response of interleukin-2 (IL-2) cultured tumor-infiltrating lymphocytes (TILs) from RCC has been nonspecific. However, in this report we describe a CD8+ TIL line derived from a primary RCC tumor that displays specificity for the autologous tumor. This line is lytic for autologous RCC but does not lyse autologous lymphoblasts, allogeneic RCC, or tumor cell lines of other histologic types. It also proliferates specifically to the autologous tumor in the absence of exogenous IL-2. However, the addition of low dose IL-2 to the cultures can significantly augment its proliferative response. When stimulated with autologous RCC but not allogeneic RCC the CD8+ line will produce interferon-gamma (IFN-gamma). It appears that recognition of RCC by this TIL line is through the TCR/CD3 complex because anti-CD3 antibody blocks the lytic activity, proliferation and IFN-gamma production of the line in response to the autologous tumor. Additional studies illustrate that cytotoxic T lymphocytes with apparent specificity for the autologous tumor are present in unseparated cultured TILs that can be detected by clonal analysis. Collectively these results suggest that there is a specific T cell response to human RCC.","PeriodicalId":77209,"journal":{"name":"Journal of immunotherapy : official journal of the Society for Biological Therapy","volume":"11 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1097/00002371-199201000-00001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12898436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cytokine and natural killing regulation of growth of a hairy cell leukemia-like cell line: the role of interferon-alpha and interleukin-2.","authors":"Z Reiter,&nbsp;O N Ozes,&nbsp;L M Blatt,&nbsp;M W Taylor","doi":"10.1097/00002371-199201000-00005","DOIUrl":"https://doi.org/10.1097/00002371-199201000-00005","url":null,"abstract":"<p><p>Hairy cell leukemia (HCL) is a lymphoproliferative disorder of B-lymphocytes, with pathological manifestations usually including splenomegaly and pancytopenia. Naturally occurring and recombinant interferons (IFNs), specifically of the alpha subtype, have shown a significant anti-tumor effect in HCL patients, with improvement of hematologic parameters within the first few months of treatment. The mechanisms responsible for the beneficial action of IFN-alpha in HCL patients are unclear, but several hypotheses have been suggested. Recently, a continuous line of cells (Eskol) from a patient diagnosed with hairy cell leukemia was established and shown to have several properties of a leukemic hairy cell. In the present study, we investigated the direct effect of IFN-alpha and interleukin (IL-2) on the Eskol cell line, and lymphokine regulation of natural killing (NK) activity against these cells. It was found that IFN-alpha has a direct antiproliferative effect on Eskol cells. Furthermore, Eskol cells were found to be completely resistant to NK-cell mediated cytotoxicity (CMC) but were somewhat sensitive to either IFN-alpha-primed NK or lymphokine-activated killer (LAK) cells-CMC. The resistance of Eskol cells to NK-CMC is due to a low binding ability to effector cells. Moreover, it was found that like IFN, IL-2 can protect Eskol cells from activated NK-CMC. Both cytokines reduced the ability of Eskol cells to induce NK-cytotoxic factor (NKCF) release from NK cells following conjugate formation between Eskol cells and effector cells. Moreover, cycloheximide treatment abolished the protective effect against NK-CMC induced by IFN-alpha or by IL-2. Therefore, it seems that the protective effect against NK-CMC induced by both cytokines is mediated via the same mechanism.</p>","PeriodicalId":77209,"journal":{"name":"Journal of immunotherapy : official journal of the Society for Biological Therapy","volume":"11 1","pages":"40-9"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1097/00002371-199201000-00005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12899112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The persistence of human peripheral lymphocytes, tumor infiltrating lymphocytes, and colon adenocarcinomas in immunodeficient mice.","authors":"D L Jicha,&nbsp;J R Yannelli,&nbsp;M Custer,&nbsp;J Colandrea,&nbsp;J Taubenberger,&nbsp;J J Mulé,&nbsp;S A Rosenberg","doi":"10.1097/00002371-199201000-00003","DOIUrl":"https://doi.org/10.1097/00002371-199201000-00003","url":null,"abstract":"<p><p>The reconstitution of severely immunodeficient mice with human peripheral blood mononuclear cells (PBMCs) may represent a unique model system to evaluate human antitumor responses. To evaluate this possibility, we studied human PBMC reconstitution, human tumor infiltrating lymphocyte (TIL) persistence, and human colon adenocarcinoma propagation in beige/nude/xid (BNX) and in severe combined immunodeficient (SCID) mice. To evaluate human PBMC reconstitution, 75 mice received 1 x 10(7)-1 x 10(9) human PBMCs i.p. or i.v. and were studied at intervals ranging from 1 to 8 weeks by fluorescence-activated cell sorting (FACS) analysis and by measurement of circulating human immunoglobulin levels. By FACS analyses, only one of 75 mice had evidence of human PBMC persistence at 2 weeks in the spleen. Moreover, liver and peritoneum showed evidence of human cells in only 13 of 56 and 16 of 55 mice, respectively. In these mice, human cells comprised 1-77% of total cells recovered. Human immunoglobulin levels in mouse serum ranged from 0 to 34,000 micrograms/ml and correlated only weakly with evidence of human PBMC reconstitution in peripheral organs, but were generally higher in SCID mice than in BNX mice. Human TIL persistence was evaluated in BNX and SCID mice that were given 3 x 10(7) TILs i.v. (in divided doses) or 1 x 10(8) i.p. TILs along with interleukin-2 administration. At 1, 2, 7, and 14 days following TIL delivery, evidence of human TIL persistence in liver, lung, peritoneum, and spleen was evaluated by FACS analysis. Fresh organ suspensions did not contain human TILs. In mice given cyclophosphamide followed by human TILs i.p., the TILs were demonstrated at 7 days in the SCID peritoneum (leu 4 = 4%) and at 2 days in the SCID spleen (leu 4 = 2%). In BNX mice, 12 of 14 fresh human colon adenocarcinomas were propagated successfully at subcutaneous sites with latency periods ranging from 1 to 13 weeks. Enzymatic disaggregation of tumors greater than 1 cm following one passage yielded 6.5-47 x 10(6) cells with viabilities ranging from 13 to 85%. We conclude that limitations and variability exist in the use of BNX and SCID mice for human PBMC reconstitution, TIL persistence, and propagation of human colon adenocarcinomas.</p>","PeriodicalId":77209,"journal":{"name":"Journal of immunotherapy : official journal of the Society for Biological Therapy","volume":"11 1","pages":"19-29"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1097/00002371-199201000-00003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12899110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase I trial of interleukin-2 plus gamma-interferon.","authors":"K A Margolin,&nbsp;J H Doroshow,&nbsp;S A Akman,&nbsp;L A Leong,&nbsp;R J Morgan,&nbsp;J Raschko,&nbsp;G Somlo,&nbsp;B Mills,&nbsp;D Goldberg,&nbsp;I Sniecinski","doi":"10.1097/00002371-199201000-00006","DOIUrl":"https://doi.org/10.1097/00002371-199201000-00006","url":null,"abstract":"<p><p>Interleukin-2 (IL-2) and gamma interferon (gamma-IFN) may be synergistic in inducing cell-mediated antitumor cytotoxicity. In order to determine the dose-limiting toxicities and define a maximum tolerated dose of these two agents in combination, we performed a Phase I clinical trial of intravenous IL-2 plus intramuscular gamma-IFN. Patients received both agents on a thrice-weekly schedule consisting of 4 weeks of treatment followed by 2 weeks of rest. Twenty-five patients were treated and received gamma-IFN doses between 0.05-0.25 mg/m2 (1-4 x 10(6) U/m2) with IL-2 doses from 0.33 mg/m2 to 2.33 mg/m2 (6-42 x 10(6) IU/m2). Two patients had partial responses of melanoma and adenocarcinoma of the lung lasting greater than 11 and 8 months, respectively. The toxicities of the combination were those expected from each agent, with no unusual effects, no irreversible organ toxicities, and no patient deaths. The doses recommended for outpatient administration on this schedule are IL-2, 2.0 mg/m2 plus gamma-IFN, 0.25 mg/m2, a dose combination that is unassociated with significant organ toxicity.</p>","PeriodicalId":77209,"journal":{"name":"Journal of immunotherapy : official journal of the Society for Biological Therapy","volume":"11 1","pages":"50-5"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1097/00002371-199201000-00006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12899113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of estradiol and tamoxifen on susceptibility of human breast cancer cell lines to lysis by lymphokine-activated killer cells.","authors":"M R Albertini,&nbsp;D F Gibson,&nbsp;S P Robinson,&nbsp;S P Howard,&nbsp;K J Tans,&nbsp;M J Lindstrom,&nbsp;R R Robinson,&nbsp;D C Tormey,&nbsp;V C Jordan,&nbsp;P M Sondel","doi":"10.1097/00002371-199201000-00004","DOIUrl":"https://doi.org/10.1097/00002371-199201000-00004","url":null,"abstract":"<p><p>The design of combination hormonal and immunotherapeutic protocols for breast cancer patients may be facilitated by analysis of preclinical in vitro model systems. Estrogen receptor positive (ER+: MCF-7) and negative (ER-: MDA-MB-231) human breast cancer cell lines were utilized to evaluate the effects of tamoxifen (TAM) and estradiol (E2) on modulation of breast cancer target susceptibility to lysis by lymphokine-activated killer (LAK) cells. E2-stimulated ER+ cells were more susceptible to lysis by LAK cells than corresponding TAM-treated or control cells, while treatment of ER- cells with either E2 or TAM alone did not alter from control their susceptibility to this immune-mediated lysis. All ER+ and ER- cells tested remained sensitive after treatment with TAM to lysis by LAK cells. In addition, an adenocarcinoma reactive human-mouse chimeric monoclonal antibody (ING-1) was able to significantly boost in vivo generated LAK cell-mediated lysis of control, E2-treated, and TAM-treated ER+ and ER- cells. These in vitro results provide a preclinical rationale for in vivo testing of TAM, interleukin-2 (IL-2), and breast cancer reactive antibody-dependent cellular cytotoxicity facilitating antibody in patients with refractory or high risk breast cancer.</p>","PeriodicalId":77209,"journal":{"name":"Journal of immunotherapy : official journal of the Society for Biological Therapy","volume":"11 1","pages":"30-9"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1097/00002371-199201000-00004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12899111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A phase II study of recombinant tumor necrosis factor in renal cell carcinoma: a study of the National Cancer Institute of Canada Clinical Trials Group.","authors":"J Skillings,&nbsp;R Wierzbicki,&nbsp;E Eisenhauer,&nbsp;P Venner,&nbsp;F Letendre,&nbsp;D Stewart,&nbsp;B Weinerman","doi":"10.1097/00002371-199201000-00008","DOIUrl":"https://doi.org/10.1097/00002371-199201000-00008","url":null,"abstract":"<p><p>The National Cancer Institute (NCI) Canada Clinical Trials Group conducted a phase II study of recombinant tumor necrosis factor (rTNF) given intravenously daily for 5 days every other week, in measurable metastatic renal cell carcinoma. Two of 26 patients responded with responses lasting greater than 200 days. Toxicity was severe including rigors, fever, headache, fatigue, hypotension, and localized pain. We conclude that rTNF, given as described, has only modest antitumor activity in renal cell carcinoma and produces considerable toxicity. We plan no further studies of rTNF in this disease.</p>","PeriodicalId":77209,"journal":{"name":"Journal of immunotherapy : official journal of the Society for Biological Therapy","volume":"11 1","pages":"67-70"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1097/00002371-199201000-00008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12899115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined antitumor therapy with the chemotherapeutic drug doxorubicin and an anti-transferrin receptor immunotoxin: in vitro and in vivo studies.","authors":"T W Griffin,&nbsp;M Stocl,&nbsp;J Collins,&nbsp;J Fernandes,&nbsp;V E Maher","doi":"10.1097/00002371-199201000-00002","DOIUrl":"https://doi.org/10.1097/00002371-199201000-00002","url":null,"abstract":"<p><p>We have determined the in vitro and in vivo efficacy of the combination of doxorubicin and an anti-transferrin receptor-monoclonal antibody (MAb)-ricin A chain immunotoxin. These agents both possess antineoplastic activity and their differing mechanisms of action and toxicities suggest that they may work well in combination. In vitro cytotoxicity was assayed by the inhibition of both 3H-leucine and 3H-thymidine incorporation into H-MESO-1 human malignant mesothelioma cells. In vivo, tumoricidal activity was determined by the effect of treatment on the survival of nude mice bearing H-MESO-1 as an intraperitoneal xenograft. The effect of doxorubicin on the antitumor activity of immunotoxin was directly compared to that of monensin, a well-described immunotoxin potentiator. The coincubation of doxorubicin (1 microM) with immunotoxin in vitro produced no increase in cytotoxicity or rate of cell kill when compared to immunotoxin alone. The addition of monensin to immunotoxin produced a significant increase in both cytotoxicity and the rate of cell kill. In animal trials, all treated groups demonstrated a significant increase in median survival when compared to controls. Treatment with doxorubicin or immunotoxin produced a mean survival time (MST) of 22 and 23 days, respectively, vs. control MST of 10 days. The combination of immunotoxin and doxorubicin increased the MST to 31 days (p = 0.004 vs immunotoxin or doxorubicin alone). Immunotoxin combined with monensin emulsion produced an increase in survival equivalent to doxorubicin/immunotoxin. The use of all three agents produced an additional improvement in survival. Combinations of standard chemotherapeutic drugs and ricin A chain immunotoxins may have additive antitumor effects in the therapy of solid tumors.</p>","PeriodicalId":77209,"journal":{"name":"Journal of immunotherapy : official journal of the Society for Biological Therapy","volume":"11 1","pages":"12-8"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1097/00002371-199201000-00002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12899109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}