Induction of tumor immunity by intratumoral chemotherapy.
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Animals↗
Biomedical subjects
T Borsos
Publications and source records attributed to T Borsos.
Lysis of tumor cells by antibody and complement. VI. Enhanced killing of enzyme-pretreated tumor cells.
The ascites form of a chemically induced guinea pig hepatoma, line-10, was resistant to killing in vitro by xenogeneic antibody and guinea pig complement. Pretreatment of line-10 cells with certain proteolytic enzymes rendered tham susceptible to the killing action of antibody and guinea pig complement. The effects of enzyme pretreatment were dependent on enzyme concentration, temperature, and could be blocked by addition of competitive or non-competitive inhibitors. The effect of the enzyme treatment could reversed by incubating the treated cells at 37 degrees C (but not at 0 degrees C), in the absence of the enzyme. Effective enzymes included ficin, bromelain, pronase, elastase, papain, trypsin, collagenase, lipases type I and type VI, and the neuraminidase preparation isolated from Clostridium perfringens. The activity of the lipase preparations and the neuraminidase preparation isolated from Clostridium perfringens appeared to be caused by proteolytic enzyme contamination. Enzyme preparations that proved ineffecitve in rendering the line-10 cells sensitive to killing by antibody and guinea pig complement included DNase, RNase, beta-glucuronidase type 6A or type B10, hyaluronidase type V or type VI, and pectinesterase.
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Studies on the terminal stages of antibody-complement-mediated killing of a tumor cell. I. Evidence for the existence of an intermediate, T.
The mechanism of the terminal steps in the lysis of antibody-sensitized tumor cells by complement (TAC) was studied. It was shown that once complement has reacted, lysis proceeded even in the absence of fluid-phase complement. Transformation of TAC to dead cells was found to be at least a two-step process: one of the steps was temperature dependent whereas the other was reversibly inhibited by EDTA. In analogy to the hemolytic system, TAC has been designated T.
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Studies on the terminal stages of antibody-complement-mediated killing of a tumor cell. II. Inhibition of transformation of T to dead cells by 3'5' cAMP.
Transformation of T to dead cells was prevented by 3'5' cAMP. The effect of 3'5' cAMP was dose, time, and temperature dependent. T washed free of 3'5' cAMP after short-term incubation proceeded to die to the same extent as control cells. After 3 hr of incubation of T with 3'5' cAMP the level of killing was significantly reduced. The 3'5' cyclic nucleotides of uridine, guanine, cytosine, and thymidine and the 2'3' cyclic adenosine nucleotide were not effective. It was concluded that prolonged treatment of T with 3'5' cAMP either irreversibly blocked the damage-producing process or facilitated the reapir of damaged sites.
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Naturally soluble tumor antigens from guinea pig hepatomas: isolation and partial characterization.
Naturally soluble tumor antigens were detected in the ascites fluid of guinea pigs bearing an ascites tumor and from exhausted tissue culture media of cultured tumor cells. Two antigenically distinct cell lines of diethylnitrosamine-induced strain-2 guinea pig hepatomas (line-10 and line-1) served as the source of tumor antigens. Tumor antigen activity was detected by four different techniques: immunodiffusion, inhibition of complement-mediated cytotoxicity, inhibition of membrane immunofluorescence, and delayed cutaneous hypersensitivity. With syngeneic tumor-specific antiserum, line-10 guinea pig tumor antigens were detected by immunofluorescence in the concentrated ascites and tissue culture fluids. With a xenogenic antiserum, demonstrated to be tumor specific, line-10 tumor antigens were detected not only in the concentrated ascites and tissue culture fluids but also in two of the partially purified fractions of these fluids. When the line-10 concentrated ascites and its fraction I were subjected to ultracentrifugation at 300,000 x G for 1 hr, the antigen activity was retained in the supernatant and thus by this criterion the tumor antigens detected in these samples are soluble. Immunodiffusion data indicate that more than one antigen is present in the line-10 system since three lines of precipitation were detected when line-10 concentrated ascites was reacted with the line-10 tumor-specific antiserum. In contrast to this, the line-10-concentrated tissue culture fluid displayed only one line of precipitation. Although tumor antigens could not be demonstrated in the other antigenically distinct tumor cell line, line-1, by immunodiffusion or inhibition of membrane immunofluorescence, inhibition of complement-mediated cytotoxicity was able to detect tumor antigens in the line-1 concentrated ascites and tissue culture fluids.
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Inhibition of antibody-complement-mediated killing of tumor cells by hormones.
Line 1, a chemically induced guinea pig hepatoma, is susceptible to killing by anti-Forssman immunoglobulin M antibody and guinea pig complement. When these tumor cells are pretreated at 37 degrees with 10(-4) to 10(-11) M concentrations of the polypeptide hormone insulin, with the catecholamine L-epinephrine-HCl, or with the glucocorticoid steroids hydrocortisone sodium succinate or prednisolone sodium succinate, the cells show a marked reduction in their suseptibility to killing by antibody and guinea pig complement; pretreatment at 0 degrees is ineffective. Similar results were obtained with another antigenically distinct guinea pig hepatoma (line 10) when tested with anti-Forssman immuno-globulin M or specific antitumor antibodies and human complement. The ability of the hormones to render the cells resistant is dependent on time, temperature, and hormone concentration. The effect of hormone treatment is maximal between 30 and 60 min and is reversible within 4 hr even in the continued presence of hormone. Treatment of line 1 cells with up to 10,000-fold greater concentrations of the less biologically active or inactive analogs, DL-epinephrine, beta-estradiol, testosterone, or proinsulin has no effect on the susceptibility of the cells to killing by antibody and guinea pig complement. The effect of hormone treatment is not due to a direct inactivation of bound or fluid-phase complement components by the hormones or to a decrease in the ability of the cells to bind complement-fixing antibody.
Antibodies, Neoplasm↗
Lysis of tumor cells by antibody and complement. VII. Complement-dependent 86Rb release--a nonlethal event?
The guinea pig hepatoma (line-1) treated with anti-Forssman antibody (TA) and GPC sequentially released 86Rb, 14C from 14C aminoidobutyric acid and failed to exclude trypan blue. Incubation of TA with fluid phase GPC for 1 min caused maximal 86Rb release; however, if the GPC was removed at this time, the cells were not subsequently killed. Using a number of naturally occurring human sera deficient in a complement component we have shown 86Rb release requires the binding of the complement components 1 through 8, but there was no absolute requirement for C9. Irreversible damage to the cell as measured by 14C AIB release or uptake of trypan blue required the complete sequence of complete sequence of complement components. These observations indicate that 86Rb release is not a relible indicator cytotoxicity.
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Studies on the terminal stages of antibody-complement mediated killing of a tumor cell. III. Effect of membrane active agents.
A comparison of the events leading from T to dead cell and E to E ghost and hemoglobin was made. Transformation of T to dead cells was inhibitable by EDTA, NaF, histamine, DMSO, cytochalasin B and 3'5' cAMP. Transformation of E to E ghost and hemoglobin was only inhibited by EDTA.
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Chemotherapeutic drugs increase killing of tumor cells by antibody and complement.
When the ascitic forms of two antigenically distinct guinea pig hepatomas induced by diethylnitrosamine are treated in vitro with chemotherapeutic drugs, their sensitivity to killing by xenogeneic antibody plus guinea pig complement increases. The effect is dependent on drug dose, is reversible, and does not appear to be due to increased antigen expression or fixation of the early acting components of guinea pig complement.
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Quantitative comparison of techniques used to measure complement-mediated cytotoxicity of nucleated cells.
?The cytotoxicity of nucleated cells by specific antibody and complement can be guantitated in vitro by several methods. Trypan blue exclusion, 51-Cr release, inhibition of uptake of 3-H-thymidine, and inhibition of colony formation are the four assays that we used to guantitatively compare the C-mediated cytotoxicity of Chinese hamster lung (CHL) cells. CHL cells were sensitized with either guinea pig or rabbit anti-CHL antisera, and exposed to guinea pig, human, or rabbit C. We found that the relative activities of the antibodies and the complements were not dependent on the method of measurement of cytotoxicity, i.e., a given pair of antiserum-complement were not dependent on the method of measurement of cytotoxicity, i.e., a given antiserum-complement titer, regardless of the assay used to measure cytotoxicity. However, the titers of the different antibody-complement pairs differed from each other.
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Immunochemical quantitaion of the third component of guinea pig complement in fluid phase and bound to cell surfaces.
A method is described for the determination of the absolute amount of guinea pig (GP) C-3 bound to cell surfaces. The test is based on the inhibition of anti-C-3 by C-3. The C-3 to be measured is added to a standard amount of anti-C-3 antibody and the residual activity is determined by its capacity to sensitize EC43-gp for lysis by GPC. By comparing the observed lysis with inhibition-of-lysis curves obtained with known C-3 antigen, the amount of test antigen can be determined. The method is simple, rapid, and reproducible and can detect nanogram amounts of C-3. The C-3 content of six normal guinea pig sera was found to be 1365 plus or minus 56 mug/ml (ranges 1120 to 1510 mug/ml) by the inhibition method described in this paper. Guinea pig hepatoma cells, line-1 and line-10, harvested from the peritoneal cavity of guinea pigs contained approximately 6.7 x 10-3 to 6.2 x 10-4 GPC-3 per cell whereas tumor cells sensitized with anti-Forssman or specific anti-tumor antibody contained from 1 to 9 x 10-5 C-3 per cell. Susceptibility to killing by antibody and GPC could not be correlated with the amount of GPC-3 bound to the surfaces of the tumor cells. Comparisons made between the amounts of C-3 bound to antibody-sensitized sheep erythrocytes and nucleated cells suggest there is a fundamental quantitative difference in the fixation of selected C components.
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Complement inhibitor(s) released by leukocytes. I. Pretreatment of sheep erythrocytes with supernatants of mouse spleen and thymus cells inhibit whole complement activity and C2 utilization.
Sheep erythrocytes pretreated with supernatants of mouse spleen or thymus cells become resistant to lysis by guinea pig complement. The inhibitory activity (IA) reduces the utilization of C2 by EAC14. Because IA binds to the surface of sheep erythrocytes and does not inhibit C1 irreversibly, it is probably a hitherto undescribed inhibitor of complement.
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Lysis of tumor cells by antibody and complement. II. Lack of correlation between amount of C4 and C3 fixed and cell lysis.
Two antigenically distinct diethylnitrosamine-induced guinea pig hepatoma cell lines, line-1 and line-10, sensitized with rabbit anti-Forssman or with tumor-specific antibody, were more susceptible to killing by human complement (HuC) than by guinea pig complement (GPC). This difference could not be ascribed to differences in the amount of C1, C4, and C3 fixed: millions of C4 and hundreds of thousands of C3 were detected on cells whether they were killed or not killed by the C sources. Tumor cells sensitized with anti-Forssman IgM antibody generally had more GP C4 and C3 than Hu C4 and C3 bound to their surfaces. Cells sensitized with anti-tumor antibody generally had more Hu C4 and C3 than GP C4 and C3 bound to their surfaces. The resistance to killing of nucleated cells by antibody and C may be due in part to intrinisic properties of the cell.
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Antigenic relationship between the fourth component of human and guinea pig complement.
Antigenic similarity between cell-bound human and guinea pig C4 was detected with antisera specific for each of these molecules. No cross-reaction could be detected between C4 of normal guinea pig or human sera or after treatment of the sera with antigen-antibody C1 complexes. The cross-reactivity between cell-bound human and guinea pig C4 may reflect conformational changes in the C4 molecule as a result of binding of the cell surface.
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Lysis of tumor cells by antibody and complement. III. Lack of correlation between antigen movement and cell lysis.
The increase in susceptibility to killing by rabbit antibody and guinea pig complement of guinea pig hepatoma cells (line-10), after treatment with certain metabolic inhibitors, did not correlate with the mobility of antigen on the cell surface as measured by indirect immunofluorescence.
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Enhancing effect by metabolic inhibitors on the killing of tumor cells by antibody and complement.
Two chemically induced, antigenically distinct guinea pig hepatoma cell lines, line 1 and line 10, which are resistant to killing by rabbit anti-Forssman or specific antitumor antibody and complement, can be rendered susceptible when the cells are pretreated with metabolic inhibitors and drugs commonly used for the treatment of cancer patients. The effect appears within 7 hr after initial contact with the inhibitors and is dependent on temperature and on inhibitor concentration; the effect is reversible within 7 hr, and the process of reversion is also temperature dependent. Not all preparations of tumor cells were rendered susceptible following treatment with inhibitors. In some cases, susceptibility to killing by complement was observed with anti-Forssman antibody but not antitumor antibody. No clear correlation between known metabolic inhibitory activity of the inhibitors and conversion to the sensitive state could be made. The results suggest that properties of nucleated cells, which are under metabolic control, play an important role in the killing efficiency of antibody and complement.
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Effect of metabolic inhibitors on the ability of tumor cells to express antigen and bind complement components C4 and C3.
Metabolic inhibitors commonly used in the treatment of cancer increase the ability of antibody and complement to kill guinea pig tumor cells in vitro. No correlation was found between increased killing and changes in cell surface antigen concentration or binding of complement components C4 and C3.
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