Active specific immunotherapy for stage II and stage III human colon cancer: a randomised trial

BACKGROUND

Colon cancer is curable by surgery, but cure rate depends on the extent of disease. We investigated whether adjuvant active specific immunotherapy (ASI) with an autologous tumour cell-BCG vaccine with surgical resection was more beneficial than resection alone in stage II and III colon cancer.

METHODS

In a prospective randomised trial, 254 patients with colon cancer were randomly assigned postoperative ASI or no adjuvant treatment. ASI was three weekly vaccinations starting 4 weeks after surgery, with a booster vaccination at 6 months with 10(7) irradiated autologous tumour cells. The first vaccinations contained 10(7) BCG organisms. We followed up patients for time to recurrence, and recurrence-free and overall survival. Analysis was by intention to treat.

FINDINGS

The 5.3 year median follow-up (range 8 months to 8 years 11 months) showed 44% (95% CI 7-66) risk reduction for recurrence in the recurrence-free period in all patients receiving ASI (p=0.023). Overall, there were 40 recurrences in the control group and 25 in the ASI group. Analysis by stage showed no significant benefit of ASI in stage III disease. The major impact of ASI was seen in patients with stage II disease, with a significantly longer recurrence-free period (p=0.011) and 61% (18-81) risk reduction for recurrences. Recurrence-free survival was significantly longer with ASI (42% risk reduction for recurrence or death [0-68], p=0.032) and there was a trend towards improved overall survival.

INTERPRETATION

ASI gave significant clinical benefit in surgically resected patients with stage II colon cancer. ASI has minimal adverse reactions and should be considered in the management of stage II colon cancer.

Long-term safety and efficacy of triamcinolone acetonide aqueous nasal spray for the treatment of perennial allergic rhinitis

This 12-month, multicenter, open-label study to assess the long-term safety and efficacy of triamcinolone acetonide (TAA) aqueous nasal spray for perennial allergic rhinitis (PAR) symptom relief was a continuation of a 4-week, double-blind study. Patients who received TAA Aqueous (220 micrograms/day) during the 4-week, double-blind study continued with the same treatment for the open label study; those randomized to placebo during the 4-week, double-blind study received TAA Aqueous (220 micrograms/day) for the open-label study. Dose reduction to 110 micrograms/day was allowed if it was felt that symptom relief would be maintained. Safety was assessed by daily diary entries and clinical laboratory results. Long-term efficacy was assessed by visual analog scale (VAS). Of the 172 patients who began the open-label study, 94.2 percent completed 3 months of treatment, 83.6 percent completed 6 months, and 62 percent completed 12 months. PAR symptom relief improved progressively throughout the study. Adverse events were generally mild or moderate and consistent with long-term use and winter symptoms. The most common adverse events were pharyngitis (32 percent of patients), rhinitis (28.5 percent), headache (22.1 percent), and epistaxis (18 percent). Adverse events related to the local effects of the study medication were similar to those observed in long-term studies with TAA aerosol. The aqueous nasal spray formulation of triamcinolone acetonide was well tolerated and continued to relieve nasal symptoms with long-term use in adolescent and adult patients with PAR.

Lipoprotein(a) serum concentration and apolipoprotein(a) phenotype correlate with severity and presence of ischemic cerebrovascular disease

BACKGROUND AND PURPOSE

Serum lipoprotein(a) [Lp(a)] levels are genetically determined and considered to be an independent risk factor for atherosclerosis. The aim of this study was to provide a complete analysis of Lp(a) serum levels, apolipoprotein(a) phenotypes, and other lipid parameters for different forms of severity of symptomatic ischemic cerebrovascular disorders as well as for different stages of carotid atherosclerosis.

METHODS

Lp(a) concentration, apolipoprotein(a) phenotype, triglyceride, low-density lipoprotein, high-density lipoprotein, and total cholesterol levels of blind-coded specimens as well as degree of carotid artery stenosis were assessed in a consecutive series of patients with ischemic cerebrovascular disease. We evaluated 265 male (34%) and female (66%) patients (mean age, 51 +/- 7.4 years) with transient ischemic attack (55.8%), prolonged reversible ischemic neurological deficits (28.3%), and cerebral infarction (15.9%) as well as 288 male (30%) and female (70%) control subjects (mean age, 51 +/- 7.1 years). All subjects were white.

RESULTS

Lp(a), total, and low-density lipoprotein cholesterol were statistically significantly elevated in all patients compared with control subjects. Lp(a) correlated with the severity of symptomatic cerebrovascular disease and the degree of carotid stenosis. Logistic regression analysis revealed Lp(a) as the best single marker for the presence of cerebrovascular disease (P < .001) followed by high-density lipoprotein cholesterol (P = .003) and triglycerides (P = .049). With a cutoff of 20 mg/dL of Lp(a), the odds ratio for a subject to have had ischemic stroke with elevated Lp(a) was 20.3 and 23.7 depending on the method of the Lp(a) estimation, whereas the odds ratio when the sonography score was > 0 was 15.4. The investigation of the distribution of the apo(a) phenotypes revealed that 16.73% of the control subjects had major isoforms < or = 580 kD molecular weight (B, F, S1, S2) versus 42.65% of the patients' group (P < .001). These isoforms were also present in 14.71% of all individuals with a sonography score of 0 but in 52.30% of all individuals with a sonography score > 0 (P < .001).

CONCLUSIONS

This case-control study shows that an elevated Lp(a) level is the primary factor associated with the presence of ischemic cerebrovascular disease and that the increased portion of the smaller-molecular-weight apo(a) isoforms in patients and individuals with a sonography score > 0 points toward an inherited predisposition for this disease.

Triamcinolone acetonide aqueous nasal spray for the treatment of patients with perennial allergic rhinitis: a multicenter, randomized, double-blind, placebo-controlled study

In this multicenter, randomized, double-blind, placebo-controlled study, 178 patients with symptoms of perennial allergic rhinitis (PAR) were treated with either triamcinolone acetonide (TAA) Aqueous nasal spray (220 micrograms once daily) or placebo for 4 weeks. Symptoms of PAR (nasal stuffiness, nasal discharge, sneezing, nasal index, and nasal itching) were evaluated throughout the treatment period through the use of patient diaries. In addition, both patients and physicians completed independent global evaluations of treatment efficacy at the conclusion of the study. TAA Aqueous provided clinically and statistically (P < or = 0.05) greater improvements in nasal stuffiness, sneezing, nasal index, and nasal itching over the 4-week study period than did placebo. Significant improvements in sneezing (P = 0.022) were observed as early as the first day (within 12 to 16 hours based on treatment in the morning and assessment of symptoms at bedtime), and in the nasal index (P = 0.009) by the third day after treatment with TAA Aqueous. Patients' and physicians' global evaluations of overall efficacy were concordant: 65% of patients rated their nasal symptoms greatly or somewhat improved with TAA Aqueous compared with 48% in the placebo group; physicians rated 66% of patients as having greatly or somewhat improved symptoms with the study drug compared with 48% of patients who received placebo. Adverse events were mild and the incidences were comparable for both groups; no significant changes in vital signs or clinical laboratory parameters were observed. This study demonstrated that TAA Aqueous administered once daily was well tolerated and provided relief of PAR symptoms in adults and adolescents.

Identification of colon-tumor-associated antigens by T-cell lines derived from tumor-infiltrating lymphocytes and peripheral-blood lymphocytes from patients immunized with an autologous tumor-cell/bacillus Calmette-Guérin vaccine

Tumor immunity developing as a response to an autologous colon-tumor/bacillus Calmette-Guérin (BCG) vaccine appears to be associated with induction of CD4+ helper T cells, implied by the observation that vaccine efficacy is associated with major histocompatibility complex class-II molecule expression on the vaccine tumor cells. Therefore, in an attempt to identify colon-tumor-associated antigens responsible for conferring immunity, we examined and compared the proliferative responses of peripheral-blood lymphocytes (PBL) from patients immunized with the autologous tumor/BCG vaccine to T-cell lines cloned expanded from colon-tumor-infiltrating lymphocytes to 5 antigens isolated on the basis of their reactivity by colon-tumor-reactive human monoclonal antibodies. Enzymatically dissociated colon tumors provided a source for establishment of cloned T-cell lines, tumor cell lines propagated in vitro or in vivo as nude-mouse xenografts and EBV-transformed B-cell lines used as antigen-presenting cells. Of 104 different T-cell lines tested, only 3 proliferated in response to CTAA 28A32-46K, and I to the CTAA28A32-32K antigen. In contrast, PBL from 64% of patients immunized with the autologous colon-tumor/BCG vaccine responded to the CTAA 28A32-32K antigen. This antigen is related to a family of calcium- and phospholipid-binding placental proteins termed annexins. Since proliferative responses developed to this antigen after vaccination in 64% of individuals, this antigen may be an important common colon-tumor-associated rejection antigen.

Quantification of lipoprotein(a) particles containing various apolipoprotein(a) isoforms by a monoclonal anti-apo(a) capture antibody and a polyclonal anti-apolipoprotein B detection antibody sandwich enzyme immunoassay

A quantitative sandwich ELISA for lipoprotein(a) [Lp(a)], utilizing a monoclonal capture antibody that recognizes human and rhesus monkey apolipoprotein(a) [apo(a)] isoforms in combination with a polyclonal anti-apolipoprotein B-peroxidase conjugate was developed. This assay generates a linear calibration curve from 31.2 to 1000 mg/L, is highly reproducible (intra- and interassay CV of < 5% and < or = 12%, respectively), and shows no interference from plasminogen (1 g/L), low-density lipoprotein (6.00 g/L), triglycerides (27.00 g/L from chylomicrons and 10.00 g/L from very-low-density lipoprotein), hemoglobin (5 g/L), or bilirubin (30 mg/L). This assay format quantifies the concentration of Lp(a) on an equal molar basis regardless of apo(a) isoform. In contrast, a commercially available ELISA [Macra Lp(a)] method with a monoclonal anti-apo(a) capture antibody and a polyclonal anti-apo(a) conjugate was found to underestimate the Lp(a) concentrations of individuals with lower-M(r) apo(a) isoforms--whether quantifying the Lp(a) in plasma or the purified lipoprotein. This demonstrates the importance of assay format selection in quantifying Lp(a).

Quantification of lipoprotein(a) particles containing various apolipoprotein(a) isoforms by a monoclonal anti-apo(a) capture antibody and a polyclonal anti-apolipoprotein B detection antibody sandwich enzyme immunoassay

A quantitative sandwich ELISA for lipoprotein(a) [Lp(a)], utilizing a monoclonal capture antibody that recognizes human and rhesus monkey apolipoprotein(a) [apo(a)] isoforms in combination with a polyclonal anti-apolipoprotein B-peroxidase conjugate was developed. This assay generates a linear calibration curve from 31.2 to 1000 mg/L, is highly reproducible (intra- and interassay CV of &lt; 5% and &lt; or = 12%, respectively), and shows no interference from plasminogen (1 g/L), low-density lipoprotein (6.00 g/L), triglycerides (27.00 g/L from chylomicrons and 10.00 g/L from very-low-density lipoprotein), hemoglobin (5 g/L), or bilirubin (30 mg/L). This assay format quantifies the concentration of Lp(a) on an equal molar basis regardless of apo(a) isoform. In contrast, a commercially available ELISA [Macra Lp(a)] method with a monoclonal anti-apo(a) capture antibody and a polyclonal anti-apo(a) conjugate was found to underestimate the Lp(a) concentrations of individuals with lower-M(r) apo(a) isoforms--whether quantifying the Lp(a) in plasma or the purified lipoprotein. This demonstrates the importance of assay format selection in quantifying Lp(a).

Delayed-type hypersensitivity reactions to tumor-associated antigens in colon carcinoma patients immunized with an autologous tumor cell/Bacillus Calmette-Guérin vaccine

Five different colon tumor-associated antigens (CTAA) were tested for their ability to induce an immune response in vivo and in vitro in ten colon carcinoma patients immunized with an irradiated autologous tumor cell/Bacillus Calmette-Guérin vaccine (active specific immunization) after resection of the primary tumor. The CTAA were defined by two different human monoclonal antibodies (MCA 1688 and MCA 28A32) derived by immortalization of peripheral blood B-lymphocytes from an active specific immunization patient. Delayed-type cutaneous hypersensitivity responses against a mixture of CTAA 28A32-50K and -32K were positive in seven of ten patients tested. In vitro T-cell responses upon stimulation with CTAA 28A32-32K were found to be positive in seven of ten patients and correlated with delayed-type cutaneous hypersensitivity responses to the antigen mixture. These data suggest that CTAA 28A32-32K might contain an important tumor-related T-cell epitope. Moreover, this method is suitable to define potential future candidates for antitumor vaccine development.

Expression of class II major histocompatibility complex molecules correlates with human colon tumor vaccine efficacy

Vaccination of colon cancer patients with X-irradiated autologous tumor cells and Bacillus Calmette-Guérin results in a significant reduction in tumor recurrence. A study was undertaken to determine whether the expression of tumor-associated antigens, expression of major histocompatibility complex molecules, or the cellular composition of the vaccine cells correlates with vaccine efficacy. A significant increase in the percentage of histocompatibility leukocyte antigen (HLA) class II molecule-expressing tumor cells was the only marker with a positive correlation. Because HLA class II molecule expression is not a prognostic marker in control patients, it was hypothesized that HLA class II molecules are involved in the induction of tumor immunity in patients treated with the autologous colon tumor vaccine. Enhancement of HLA class II molecule-expressing cells could be induced in X-irradiated colon tumor cells injected into the skin of mice when the cells were mixed with gamma-interferon. Therefore, addition of gamma-interferon to the colon tumor vaccine, resulting in increased numbers of HLA class II molecule-expressing cells, could potentiate the generation of tumor immunity.

Acarex test correlates with monoclonal antibody test for dust mites

Forty-two dust samples from the homes of patients having positive mite skin tests were tested by both monoclonal antibody and Acarex techniques. A Spearman's correlation coefficient of 0.85 (p = 0.0001) was found. The Acarex test is simple to use and is much less expensive than the monoclonal antibody method. The use of either method may enhance patient compliance with mite-control instructions and may prove crucial to the effective use of miticides in infested homes.

Dust mite assays in clinical allergy practice: mite antigen exposures among skin test positive patients in Kansas

We have attempted to determine whether sensitive monoclonal antibody assays for Dermatophagoides mite antigens Der p I and Der f I can be carried out in a private clinical allergy practice laboratory, to ascertain incidence of significant home mite exposure in dust samples from patient homes in Kansas, and to consider whether such information impacts on patient management. We analyzed 152 dust samples from 62 patient homes. All patients were skin prick test positive for one or both common mite species available for skin testing, and had potentially relevant histories. Der p I and Der f I antigen levels were added together, and levels above 2 micrograms/g of dust were considered "positive." By this definition, elevated levels were found in at least one sample from 48 of 62 homes tested (77%); however, 61% of mattress samples tested, 41% of carpet samples, and 54.5% of furniture samples had levels below those considered likely to cause symptoms. Only 13 of 152 samples yielded Der p I levels above 2 micrograms/g. We conclude that monoclonal antibody assays for Der p I and Der f I antigens can be performed in a well-equipped office laboratory staffed by trained medical technologists, that Der f I is the predominant mite species in Kansas, and that data derived from mite assays may be important in treatment planning for patients suspected of having mite-related allergy symptoms.

Diagnostic fiberoptic rhinolaryngoscopy

This paper reviews observations made on 324 patients undergoing video rhinolaryngoscopy at the Topeka Allergy and Asthma Clinic because of symptoms related to the nose and throat. Many abnormalities were found, and the observations made were considered very helpful in the diagnosis and management of these problems. The procedure is quite safe, and the risk-benefit ratio appears very favorable. Playback capability provides an excellent tool for patient education. Physicians using this procedure must maintain a sufficient case load of rhinology patients to justify the equipment expense and to maintain the requisite level of expertise. Fiberoptic rhinolaryngoscopy under video control and with video recording/playback capability may be the procedure of choice for the diagnosis of most anatomic and functional abnormalities of the nose, nasopharynx and glottic structures.

Leukoregulin inhibits the growth of human glioblastoma in vitro

Growth of cultured human glioblastoma cells was profoundly inhibited by concentrated lymphokines prepared from mitogen-activated blood mononuclear cells of normal donors. Cloning efficiency of glioma cells and their absolute number were decreased as well. Partially purified leukoregulin, free of lymphotoxin, tumor necrosis factor and gamma-interferon, similarly suppressed DNA synthesis and clonogenicity. The decrease in absolute numbers of tumor target cells indicated that leukoregulin was directly cytolytic as well as cytostatic for human glioblastoma cells. Our data indicate that leukoregulin is at least one of the factors produced by activated lymphocytes which inhibits the proliferation of human glioblastoma in vitro.

Analysis of a cytostatic lymphokine produced by incubation of lymphocytes with tumor cells: relationship to leukoregulin and distinction from recombinant lymphotoxin, recombinant tumor necrosis factor, and natural killer cytotoxic factor

Supernatants from the coculture of peripheral blood lymphocytes and the NK-susceptible cell line K562 were highly growth inhibitory for a variety of tumor cell lines. No correlation was observed between the susceptibility of the target cell lines to growth inhibition and to lysis by NK cells. Rather, the spectrum of cytostatic activity and the characteristics of the soluble factor were similar to those of leukoregulin, a recently described lymphokine. The supernatants of tumor-lymphocyte cultures contained only low levels of IFN-alpha and IFN-gamma, and antibodies to interferons did not affect the observed growth inhibition. The pattern of target cell susceptibility to growth inhibition by this factor was also quite distinct from that seen with purified recombinant LT or TNF. Furthermore, monoclonal antibodies to these cytokines also had no effect on the cytostasis, arguing against a requirement for, or synergistic interaction with, low levels of these cytokines. Some of the targets susceptible to the factor were only growth inhibited but not lysed, thereby distinguishing it from NKCF. Furthermore, the cytostasis was not inhibited by mannose-6-PO4 or rabbit antibodies to granule cytolysin, both of which have been reported to block NKCF. Therefore, the results show that a cytostatic factor is released in tumor-lymphocyte incubation that is quite distinct from interferons, LT, and TNF but has characteristics that resemble those of leukoregulin.

Leukoregulin, a direct-acting anticancer immunological hormone that is distinct from lymphotoxin and interferon

Human lymphokine preparations can directly lyse or suppress proliferation of human tumor cells or can enhance the susceptibility of human tumor cells to lysis mediated by natural killer lymphocytes. In the past, these antitumor activities were attributed to lymphotoxin. This study demonstrates, however, that these human lymphokine antitumor cell activities are biochemically separable from lymphotoxin and are properties of a lymphokine which was named leukoregulin because it is produced by lymphocytes and it regulates target cell physiology and growth. Leukoregulin obtained by high-performance liquid chromatography and isoelectric focusing was free of detectable lymphotoxin, interferon, interleukins 1 and 2, and macrophage-activating factor activities. Leukoregulin has an apparent molecular weight of 135,000 as measured by linear gradient polyacrylamide gel electrophoresis and gel filtration chromatography and has isoelectric pHs of approximately 5.3 and 7.5. The molecular weight of leukoregulin, determined in the dissociating conditions of sodium dodecyl sulfate polyacrylamide gel electrophoresis, was 32,000. Flow cytometric analysis showed that tumor cell lysis, growth inhibition, and enhancement of susceptibility to natural killer cell-mediated cytotoxicity by leukoregulin were accompanied by rapid alterations in tumor cell membrane permeability. Lymphotoxin from human peripheral blood leukocytes and highly purified lymphotoxin from RPMI 1788 human lymphoblastoid cells lysed murine alpha-L929 tumor cells but did not possess any of the direct acting antihuman tumor cell cytostatic, cytolytic, or natural killer cell enhancing activities that leukoregulin exhibited against a broad spectrum of human tumor cell lines. The dual modes of the anticancer actions of leukoregulin, direct cytotoxicity and indirect enhancement of natural killer cell cytotoxicity, make leukoregulin a unique-acting lymphokine and suggest several ways in which leukoregulin may be used as a therapeutic agent against cancer.

Intravenous injection of unanesthetized hamsters (Mesocricetus auratus)

A rubber band tourniquet was applied to the proximal portion of the foreleg of unanesthetized male and female golden hamsters followed by intravenous injection in the cephalic vein using a 25 gauge needle. Volumes up to 0.3 ml could be injected easily.

Molecular and biological characterization of anticarcinogenic and tumor cell growth-inhibitory activities of Syrian hamster lymphotoxin

Syrian hamster lymphotoxin has three identified anticancer activities: (a) cytolytic activity measured as the release of 3H from [3H]thymidine-labeled murine alpha L-929 cells; (b) cytostatic activity assessed by the inhibition of cell colony formation of tumorigenic Syrian hamster cells; and (c) anticarcinogenic activity measured by inhibition of chemical carcinogen or radiation-induced morphological transformation of Syrian hamster fetal cells in vitro and in vivo. Lymphotoxin cytolytic, cytostatic, and anticarcinogenic activities have similar molecular weights of approximately 45,000 by ACA-44 Ultrogel chromatography. A three-step purification of (a) diafiltration and concentration, (b) column isoelectric focusing in a pH 4 to 6 gradient, and (c) ACA-44 Ultrogel column chromatography yields 25% recovery of lymphotoxin cytolytic and anticarcinogenic activities. The three-step purified lymphotoxin is free of detectable interferon, macrophage migration inhibitory factor, and mitogenic factors inducing hamster T-lymphocyte proliferation and is anticarcinogenic in vivo. The purified lymphotoxin had a specific anticarcinogenic activity of 58,500 units/mg of protein and a molar specific activity of 2,900 units/nmol. Although homogeneous in molecular size, the purified lymphotoxin is comprised of several molecular species. Cytolytic activity is associated with molecules having a single major isoelectric point of 5.0, whereas the cytostatic and anticarcinogenic activities comigrate with molecules with major isoelectric points of 5.0 and 4.6. This is the first evidence that the anticancer actions of lymphotoxin are properties of similarly sized but several different electrically charged molecules and that the several lymphotoxin species have differing anticancer activities.

Lymphotoxin amplification of tumor growth inhibition is specific for natural killer cells but not for macrophages

Lymphotoxin augments the susceptibility of tumorigenic guinea-pig cells to natural killer (NK) cell cytolysis in vitro but does not directly stimulate either NK cell or macrophage cytolytic action. The question whether lymphotoxin enhances the susceptibility of tumorigenic guinea-pig cells to cytolysis or other means of growth inhibition in vivo by syngeneic NK cells or macrophages was, therefore, examined using a modified tumor cell neutralization (Winn) assay. Mineral oil-, thioglycollate- or casein-induced peritoneal leukocytes, but not the macrophages isolated from the elicited leukocytes obtained from nonimmunized strain 2/N guinea-pigs, effected enhanced cytolysis of lymphotoxin-treated guinea-pig benzo (a)pyrene-induced 104CI tumor cells in vitro. Neither guinea-pig splenic NK cells nor oil-induced peritoneal macrophages alone inhibited the growth of 104CI cells as tumors in vivo when admixed with 104CI cells and injected into guinea-pigs. However, when the 104CI cells were treated with lymphotoxin before addition of effector cells, NK cells but not macrophages significantly reduced tumor growth in vivo. Therefore, the ability of lymphotoxin to increase the sensitivity of tumor cells to destruction mediated by natural leukocytes is specific for NK cells as compared to macrophages. This form of lymphokine amplification of natural leukocyte cytotoxicity may be one mechanism by which natural and acquired immunity serves or fails to prevent cancer and should be an important consideration in therapeutic approaches to eradicate or control tumor growth.

Endothelial cell growth supplement: a cell cloning factor that promotes the growth of monoclonal antibody producing hybridoma cells

The efficiency of endothelial cell growth supplement (ECGS), a commercially marketed extract of bovine neural tissue, human endothelial cell supernatant (HECS) derived from freshly isolated endothelial cells, and feeder layers of murine peritoneal cells (PEC), were compared for their ability to support cell fusion, clonal growth, and monoclonal antibody production of murine hybridoma cells. ECGS at 25-100 micrograms/ml was similar to a 1:5 dilution of HECS in supporting the growth of hybridoma colonies; both ECGS and HECS were superior to PEC feeder cells. Furthermore, hybridomas cloned in ECGS produced anti-lymphotoxin antibodies. The commercial availability and stability of ECGS together with its ability anti-lymphotoxin antibodies. The commercial availability and stability of ECGS a superior growth supplement for the fusion and growth of hybridoma cells in monoclonal antibody production.

Identification of beta-lymphotoxin as the predominant molecular class of in vitro and in vivo Syrian hamster lymphotoxin

The molecular class of Golden Syrian hamster lymphotoxin produced in vitro and in vivo was determined by size-exclusion high-performance liquid chromatography using silica-based protein separation columns eluted with a 0.1 M sodium phosphate, pH 7.4 buffer containing 0.1% Mr 4000 polyethylene glycol. Lymphotoxin cytolytic activity was quantitated in the column effluent by measuring the ability of the fractions to lyse alpha-L929 cells as indicated by [3H]TdR release. Lymphotoxin activity induced by an 8- or 24-hr or 5-day phytohemagglutinin stimulation of peritoneal leukocytes, by 24-hr phytohemagglutinin-coated alpha-L929-cell stimulation of peritoneal leukocytes, or by 24-hr phytohemagglutinin stimulation of spleen cells occurred in the Mr range of 20,000-56,000, with major components in the 35,000-50,000 beta-lymphotoxin region. No activity was present in the complex (greater than 200,000) region and only minimal activity was detectable in the alpha (70,000-160,000) and gamma (12,000-20,000) regions. In vivo-induced lymphotoxin, obtained by peritoneal lavage 48 hr after intraperitoneal administration of phytohemagglutinin, was entirely beta-lymphotoxin and was not detectable in the plasma. Lymphotoxin produced in vitro and injected simultaneously with the gamma-emitting radionuclide 99mtechnetium, inhibited in vivo development of radiation-induced transplacental carcinogenesis. Thus, Syrian hamster lymphotoxin with antitumor activity consists of glycoproteins with isoelectric points of 4.8-5.2, Mr of 20,000-56,000, and major in vitro and in vivo forms in the beta-lymphotoxin range.

Control of the carcinogenic potential of 99mTechnetium by the immunologic hormone lymphotoxin

Immunologic prevention of the carcinogenicity of the diagnostic gamma-emitting radionuclide 99mTechnetium (99mTc) by lymphotoxin was evaluated using an in vivo-in vitro assay of carcinogenesis. Pregnant Syrian golden hamsters received 125-2,300 microCi 99mTc/kg body weight by injection, and 7 days later colonies of morphologically transformed cells were quantitated in vitro. The transformation frequency increased directly with the radionuclide concentration, and cells derived from transformed colonies produced tumors in athymic nude mice. The total absorbed 99mTc dose was 0.20 rad following injection of 250 microCi 99mTc/kg hamster body weight; this compares with an exposure of 0.13 rad following injection of 143 microCi 99mTc/kg body weight in humans. Intravenous injection of purified hamster lymphotoxin immediately after 99mTc caused a dose-dependent reduction in the transformation frequency. Transformation was essentially completely prevented (97%) by injection of 8,000 U of lymphotoxin. Thus, the immune system, through the action of lymphotoxin, has the potential to prevent carcinogenesis induced by gamma-radiation from 99mTc. This emphasizes the importance of considering the recipient's immune and other homeostatic mechanisms as part of a complete diagnostic or therapeutic gamma-radiation regimen.

Lymphotoxin prevention of diethylnitrosamine carcinogenesis in vivo

Development of intervention measures to control cancer would be facilitated by being able to monitor in vivo carcinogenesis by in vitro quantitation of early indices of neoplastic transformation to assess the in vivo effectiveness of preventive-therapeutic measures. Pregnant Syrian golden hamsters were used in an in vivo-in vitro transplacental model of carcinogenesis to determine the extent that in vivo administration of immunologic hormone preparations along with chemical carcinogen would prevent morphologic transformation assessed in vitro. Pregnant hamsters at 10-11 days of gestation were given injections ip of 3 mg diethylnitrosamine (DENA)/100 g body weight and were killed 2 days later when fetal cells were seeded for colony formation. The frequency of morphologically transformed colonies was assessed after 7 days of growth. Cloning efficiency and mean transformation frequency after DENA exposure were 3.6% and 1 X 10(-4) per cell seeded, respectively. The ip injection of an immunologic hormone preparation reduced the transformation frequency by 46%. The hormone preparation, containing 10,000 U of lymphotoxin but no detectable interferon, was the ultrafiltered lymphokines (greater than 10,000 mol wt) from phytohemagglutinin-stimulated hamster peritoneal leukocytes. The effect of lymphotoxin on cocarcinogenic exposure of fetal cells to DENA in vivo followed by X-irradiation in vitro was also determined. Cells exposed to 250 rad in vitro had a cloning efficiency of 0.5% and a transformation frequency of 0.4 X 10(-4) per cell seeded. After DENA injection and X-irradiation, the transformation frequency increased to 1 X 10(-4) and was inhibited 64% by lymphotoxin in vivo. Thus immunologic hormones (e.g., lymphotoxin) can prevent carcinogenesis in vivo. Furthermore, in vitro quantitation of transformation is a rapid means for evaluating therapeutic and autochthonous effector mechanisms for their ability to prevent or otherwise modulate carcinogenesis in vivo.

Lymphotoxin enhances the susceptibility of neoplastic and preneoplastic cells to natural killer cell mediated destruction

Treatment of neoplastic guinea-pig cells for 1-14 days with 300 units of guinea-pig lymphotoxin/ml medium enhanced 2- to 5-fold their susceptibility to natural killer (NK) cell-mediated cytotoxicity as measured by 4 h 51Cr and 72 h [3H]-thymidine-release assays. The NK susceptibility of human neoplastic and guinea-pig non-neoplastic cells refractory to guinea-pig lymphotoxin growth-inhibitory activity was unchanged after lymphotoxin treatment. Lymphotoxin preparations were free of detectable interferon and the enhancing activity copurified with lymphotoxin during diafiltration and isoelectric focusing. Treatment of NK cells with lymphotoxin preparations also augmented NK-mediated lysis but that activity did not copurify with lymphotoxin. As with neoplastic cells, lymphotoxin-sensitive preneoplastic cells previously treated with ultraviolet light, a chemical carcinogen, or carcinogen and the tumor-promoting agent tetradecanoylphorbol-acetate also exhibited lymphotoxin enhancement to NK-cell destruction. Thus, the immunologic hormone lymphotoxin enhances the susceptibility of lymphotoxin-sensitive cells to NK-cell destruction, indicating that these two natural immune mediators, lymphotoxin and NK cells, have the potential in concert to regulate carcinogenesis and neoplastic growth.

Kinetics of the immune response of tumor-bearing hamsters to two simian virus 40 coded non-structural polypeptides present in simian virus 40 tumor cells

The kinetics of the immune response of hamsters transplanted with virus-free SV40 tumor cells (TSV5) to two SV40-coded non-structural proteins of 94,000 daltons (T antigen) and 17,000 daltons (t antigen) was studied in order to determine if the variation in the immune reactivity of serum from tumor-bearing animals towards these proteins can be explained on the basis of differential immune response during various stages of tumor growth. The results demonstrate that individual animals vary in their capacity to respond immunologically to T and t antigens in SV40-transformed cells and that, further, the immune response to T and t antigens is influenced by the stage of tumor development.

Allergic reactions to enzymes used in plant cloning experiments

We report a case of rhinitis and asthma resulting from exposure to enzymes used in an experimental plant pathology laboratory. Immediate skin-test responses were elicited to both "Cellulase" and "Macerozyme" products, and a large late onset skin reaction occurred at the Cellulase site beginning in 6 hr. Special radioallergosorbent test (RAST) substrates were prepared that showed a strong positive response to Cellulase. By the RAST method other laboratory workers were screened and another symptomatic individual was found who also showed evidence of type I hypersensitivity to both enzymes. Skin biopsy and immunodiffusion data are presented. We conclude that enzymes used to digest cell wall structures of plants are capable of eliciting both immediate and late onset skin-test reactions and positive RAST responses in susceptible persons. These reactions are thought to be mediated by IgE antibodies and can be associated with symptoms of rhinitis and asthma.

Solubilization and partial characterization of a tumor-rejection antigen from an ultraviolet light-induced murine tumor

Tumor rejection antigen (TRA) of an ultraviolet-light-induced murine skin tumor was solubilized, fractionated and partially characterized. Subcellular fractions were prepared by differential centrifugation of tumor cells that had been ruptured via nitrogen cavitation. Only the 110,000-g membrane fraction induced significant tumor protection, as determined by in vivo immunization and challenge assays. Extraction of the membrane fraction with 3 M KCI resulted in solubilization of material that could induce in vivo tumor-rejection immunity. Both the membrane fraction and soluble extract had a limited effective dose range. The KCI extract was separated on a Sepharose, CL-6B column in the presence of 6 M guanidine-HCI. Only one of five fraction pools (molecular weight range of 76,000-127,000 daltons) was immunogenic. It contained at least eight protein bands by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), but no lipid components. This immunogenic Sepharose fraction was chromatographed on a Sephadex G-150 column. Each of the four Sephadex fraction pools was immunogenic. One protein component was common to each of those fractions. It migrated as a single 76,000-dalton band on SDS-PAGE and contained [14C]-leucine and [3H]-glucosamine that had been incorporated during cell growth. These results suggest that the TRA of this tumor is a 76,000-dalton glycoprotein.

Immunological monitoring in a controlled trial of immunotherapy in stage IIB malignant melanoma

Fifteen patients undergoing surgery for Stage IIb malignant melanoma were randomly allocated either to a group who received a vaccine of BCG mixed with irradiated autologous melanoma cells, or a control group who received no further treatment. All patients were monitored sequentially for immunological competence and tumour-directed immunity, using a wide range of techniques, and the results were compared retrospectively with their clinical course. Three months after surgery, there was a trend towards inhibition of PHA-induced lymphocyte transformation by autologous serum in patients who developed recurrent tumour within 12 months after treatment. Serum from patients who remained tumour-free for 12 months did not inhibit stimulation of autologous lymphocytes by PHA. Apart from this test, no other immunological parameters correlated either with clinical course or with the type of treatment received.