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Biomedical subjects

H Fuji

Publications and source records attributed to H Fuji.

At least 55 records · Page 3Linked to original sources
PubMed1984

Immunomodulation of host resistance by tumor variants.

Immunomodulation of host resistance by tumor cell variants has been investigated in the context of immunological effects of tumor cell heterogeneity using a murine tumor model. Clonal variation in the susceptibility to specific T cell-mediated cytotoxicity (TC), which is inversely related to tumorigenicity in syngeneic animals, was demonstrated among clones derived from a cultured line of DBA/2 lymphoma L1210 by limiting dilution. Thus, although a majority of such clones were TC-resistant and highly tumorigenic, some clones were TC-susceptible and non-tumorigenic. Moreover, an inoculation of the variant clones bearing the latter phenotype was shown to elicit protective immunity in host mice against a challenge with the parent L1210, whereas an inoculation of spleen cells (or extracts) from hosts bearing tumorigenic clones would abrogate the priming effects of the non-tumorigenic variants, presumably through splenic suppressor cells. These results suggest that heterogeneity among variant clones may influence the regulation of host resistance against tumors.

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PubMed1983

Ricin A-chain conjugated with monoclonal anti-L1210 antibody. In vitro and in vivo antitumor activity.

In studies of antitumor antibody-cytotoxic agent conjugates as potential antitumor agents with improved tumor specificity, the toxic subunit A-chain of ricin was conjugated with a monoclonal antibody to a tumor-associated antigen expressed weakly on murine leukemia L1210 cells and strongly on L1210/GZL cells, a guanazole-resistant subline of L1210, employing N-succinimidyl 3-(2-pyridyldithio)propionate as cross-linking agent. The conjugate (anti-L1210 conjugate) exhibited a potent concentration-dependent cytotoxicity against cultured L1210/GZL cells, and inhibited cell growth at concentrations over 0.8 micrograms/ml. The conjugate killed all L1210/GZL cells at a concentration of 100 micrograms/ml. Neither nonimmune conjugate similarly prepared from mouse nonimmune IgG nor unconjugated anti-L1210 IgG alone showed cytotoxicity against L1210/GZL cells. When (BALB/c X DBA/2)F1 mice inoculated with 1 X 10(5) L1210/GZL cells were treated with IP injections of 27 micrograms anti-L1210 conjugate 1 h and 5 days after tumor cell inoculation, a life-prolonging effect was observed. [Lifespan in treated animals as percentage of that in controls (T/C) = 146%]. However, when the dose per injection was increased to 50 micrograms per mouse, survival was the same as in the control group. Postmortem examination of mice that had been treated with 50 micrograms anti-L1210 conjugate revealed lesions with necrosis and hemorrhage in the liver parenchyma and the intestinal epithelium, respectively. A similar toxic effect on the host mice was also observed with nonimmune conjugate.

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PubMed1983

Differential tumor immunogenicity of DBA/2 mouse lymphoma L1210 and its sublines. III. Control of host resistance to drug-resistant L1210 sublines by H-2-linked and non-H-2-linked genes.

The effects of the host's genetic composition on the host's resistance to the DBA/2 L1210 lymphoma and three drug-resistant L1210 sublines (which show an increased expression of tumor-associated antigens) were investigated. Histocompatible F1 mice between DBA/2 and other mouse strains were given injections ip of graded numbers of these tumor cells, and a marked difference in the resistance of the host to tumor growth was demonstrated. The resistant hybrid mice showed markedly higher resistance to the L1210 sublines than to the L1210 parent lymphoma cells. Experiments with F1 mice between DBA/2 (H-2d) and certain congeneic intra-H-2 recombinant strains showed that the H-2b/d heterozygosity at the H-2K+l-A regions and additional non-H-2 genetic factor(s) confer the resistance to the F1 mice. The resistance was abolished by treating host animals with injections of silica, an antimacrophage agent, or rabbit anti-mouse thymocyte serum. These results suggest that the resistance is immunologic and that the genetically controlled host resistance may be directed to surface changes related to the increased expression of tumor-associated antigens.

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PubMed1983

Differential antigenic expression of the DBA/2 lymphoma L1210 and its sublines: cross-reactivity with C3H mammary tumors as defined by syngeneic monoclonal antibodies.

The expression of tumor-associated antigens on the DBA/2 lymphoma L1210 and three L1210 sublines, each resistant to a different antileukemic agent [guanazole, methylglyoxal-bis(guanylhydrazone), and 4,4-diacetyldiphenylurea-bis(guanylhydrazone)] was investigated by the use of monoclonal hybridoma antibodies. Hybridomas were produced by the fusion of spleen cells from DBA/2 mice immunized with irradiated L1210 or L1210 subline cells and cells of a non-immunoglobulin-secreting BALB/c myeloma variant. Three clones producing antibodies reacting with L1210 or L1210 subline cells were used to study the antigenic expression of L1210 and L1210 subline cells. Monoclonal antibodies from anti-L1210 and anti-L1210 subline hybridomas exhibited a greater reactivity with L1210 subline cells than with L1210 cells in complement-dependent cytotoxicity, quantitative absorption, and membrane immunofluorescence experiments, thereby demonstrating a tumor-associated antigen shared by L1210 and the L1210 sublines and an increased expression of this antigen on subline cells. Cross-blocking tests of antibody binding demonstrated that monoclonal antibodies from anti-L1210 and anti-L1210 subline hybridomas recognized the same or very closely situated antigenic determinants on the tumor cell surface. Most syngeneic and allogeneic tumor cells used as controls failed to react with the anti-L1210 and anti-L1210 subline hybridoma antibodies. However, two syngeneic tumors, L5178Y and P388-D1, demonstrated a significant reaction with the monoclonal antibodies. In addition, several spontaneous mammary tumors from C3H/St and DBA/2Ha, both high-frequency mammary tumor strains, reacted in various degrees with anti-L1210 or anti-L1210 subline hybridoma antibodies in absorption tests and in immunofluorescence experiments. On the other hand, liver, kidney, and spleen from normal C3H/St mice, as well as mammary tumors from BALB/c and C3Hf, both low-frequency mammary tumor strains, did not demonstrate significant reactivity in similar experiments. Normal lactating mammary glands from high-frequency mammary tumor mouse strains reacted with the monoclonal antibodies, whereas lactating mammary glands from low-frequency mammary tumor mouse strains were negative by this method. Purified murine mammary tumor virus preparations reacted strongly with the monoclonal antibodies in solid-phase radioimmunoassays, whereas a purified murine leukemia virus preparation failed to do so in similar experiments. These results indicate that the tumor-associated antigen(s), differentially expressed on L1210 and L1210 subline cells, is related to an antigen which is associated with the murine mammary tumor virus.

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PubMed1982

Monoclonal antibodies recognizing tumor-associated antigen of human ovarian mucinous cystadenocarcinomas.

Spleen cells from BALB/c mice immunized with human ovarian cystadenocarcinoma extract were fused with the mouse myeloma cell line P3/NSI/1-Ag 4 in the presence of polyethylene glycol (Mr 4000). Of the 46 hybrids obtained, four secreted antibodies preferentially reactive to the immunizing ovarian tumor extract. Two of these hybrids, which showed no reaction with normal controls, were selected for cloning by the limiting dilution method. The numerous clones obtained from each hybrid were screened against a panel of five ovarian tumor extracts, pooled normal ovary extracts, and pooled normal human sera. One clone from each hybrid that showed specificity for ovarian mucinous cystadenocarcinomas was recloned to assure monoclonality and to establish a permanent hybridoma cell line. The antibodies secreted by these cell lines were of IgG1 subclass with kappa light chains. These antibody-producing hybridomas were selected for further analysis of the antibody specificity by a solid-phase radioimmunoassay and quantitative absorption tests. The monoclonal antibodies recognized an antigenic determinant present only in mucinous cystadenocarcinomas of the ovary. These did not react with any other gynecological or nongynecological tumor thus far tested. The antigen was not demonstrable in any normal adult tissues tested. Among fetal tissues examined, only fetal intestine extract showed a positive reaction. The antigenic determinant recognized by these monoclonal antibodies was unrelated to carcinoembryonic antigen, normal glycoprotein, normal human serum components, or human ABO blood group materials. These antibodies, which have relatively high affinity and can be produced in large amounts, will be useful for the isolation and immunochemical characterization of this antigen. The purified antigen and the specific antibodies could be then combined in a sensitive radioimmunoassay for the early detection of the antigen in the sera and body fluids of patients with ovarian mucinous cystadenocarcinomas.

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PubMed1980

Monoclonal antibody-recognizing tumor-associated antigen of DBA/2 mouse lymphoma L1210 and its sublines.

Tumor-associated antigens of DBA/2 lymphoma L1210 and three immunologic drug-resistant L1210 sublines were studied by monoclonal antibodies produced by fusing non-Ig secreting BALB/c myeloma cells with spleen cell of DBA/2 mice immunized with L1210 subline cells that are syngeneic with respect of DBA/2 mice. After the cell fusion, two stable clones of antibody-producing hybridomas were selected for further analysis of the antibody specificity by complement-dependent cytotoxicity and quantitative absorption tests. These clones produced a cytotoxic antibody(s) of IgG2 class recognizing a TAA(s) that was expressed strongly on cells of the immunizing subline as well as on cells of their L1210 sublines, but weakly on the parental L1210 cells. Control normal syngeneic mouse tissues and tumors of syngeneic and allogeneic origins, including those that carry known murine leukemia virus-associated antigens, showed no significant reaction with the antibody, whereas two DBA/2 tumors (i.e., L5178Y and p388-D1) showed weak reactivity. Since all three L1210 sublines were more immunogenic than the parental L1210 cells in eliciting host's tumor graft rejection and contained more TAA than the parent line, the data suggest that the monoclonal antibody obtained may be defining the TAA that is involved in tumor rejection.

Absorption↗
PubMed1979

Influence of inoculation site on development of the Lewis lung carcinoma and suppressor cell activity in syngeneic mice.

The growth of the Lewis lung carcinoma (3LL) was studied in syngeneic C57BL/6 mice inoculated sc with similar numbers of tumor cells in either the flank or the hind footpad (fp). After injection of small numbers of 3LL cells, the incidence of tumors was lower in the flank than in the fp. However, after a successful 3LL transplant, tumors in the flank progressed faster than those in the fp, as evidenced by the early metastatic dissemination to the lungs and the shorter survival of the hosts. Local adoptive transfer tests demonstrated the early appearance of suppressor cell activity in spleens from mice bearing tumors in the flank. Adult thymectomy as well as treatement with antithymocyte serum after the tumor transplant inhibited the growth of a flank tumor but did not modify significantly that of an fp tumor. Thus variations in the site of a subcutaneous tumor implant resulted in differences in tumor development that appeared to depend on the characteristics of the immune response elicited by the inoculum.

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PubMed1977

Differential tumor immunogenicity of L1210 and its sublines. I. Effect of an increased antigen density on tumor cell surfaces on primary B cell responses in vitro.

The differential immunogenicity of DBA/2 lymphoma L1210 and three L1210 sublines, each resistant to a different anti-leukemic agent (guanazole, methylglyoxal-bis-guanylhydrazone, and 4,4-diacetyldiphenylurea-bis-guanylhydrazone), was evaluated in vitro. Syngeneic spleen cells from nonimmunized DBA/2 mice were cultured in the presence of graded numbers of irradiated cells of L1210 or its sublines. The stimulation elicited a T-independent primary antibody response in vitro which was measured by determining the number of plaque-forming cells by using the immunizing lymphoma cells as target. Cells of all three sublines exhibited an increased immunogenicity, as compared to that of the parental L1210 cells, in eliciting the response directed to tumor-associated antigens which were common to all sublines. Dose-response experiments showed that high doses of the parental cells did stimulate responses which were detectable with subline cells as target. The results indicated that the differential immunogenicity of L1210 and its sublines, as demonstrated in the present assay system, is primarily quantitative, and was apparently due to increased amount or density of common tumor-associated antigens on the subline cells. The implications of these observations are discussed in relation to the possible mechanisms underlying the emergence of highly immunogenic drug-resistant sublines.

Animals↗
PubMed1975

Primary antibody response against K and D regions of the H-2a and H-2d haplotypes.

The capacity of D and K antigens of the H-2d and H-2a haplotypes to induce primary IgM response was evaluated in host-donor combinations using congenic recombinant strains of mice. Host animals were immunized with an i.p. injection of 2 X 10(7) allogeneic spleen cells. Direct plaque-forming cells appearing in immune spleens were assayed with cells of lymphomas L2 of strain A and L5178Y of strain DBA/2, and mastocytoma P815 of strain DBA/2, as targets. Serum antibodies were titrated for cytolytic activity with the same targets as above, and with spleen cells of strain A mice. Titration of serum hemagglutinins was performed using A erythrocytes. The following results were obtained: (1) H-2Dd antigens were shown to be more potent in stimulating primary IgM antibody response than were H-2Kk and H-2Kd antigens, as measured by both plaque assay and serum antibody titration. (2) The observed dominance of D antigens of the haplotypes under study did not seem to be dependent on the number of antigenic specificities involved. (3) Comparable results were obtained with both lymphoid and nonlymphoid target cells of either normal or malignant origin.

Animals↗
PubMed1975

Selection for high immunogenicity in drug-resistant sublines of murine lymphomas demonstrated by plaque assay.

The immunogenicity of lymphoma L1210 and three L1210 sublines, resistant to methylglyoxal bis(guanylhydrazone), 4,4'-diacetyldiphenylurea bis(guanylhydrazone), or guanazole (L1210/GZL), respectively, was evaluated. Syngeneic DBA/2J mice were given a single i.p. injection of serially diluted suspension of irradiated cells from L1210 or L1210 sublines. Five days later spleen cells from the immunized mice were tested for the presence of plaque-forming cells using the immunizing lymphoma cell lines as target. Sera collected from the animals were examined for cytolytic antibody activity by lysis in gel using the same target cells. For comparison, the H-2 immunogenicity of L1210 and its sublines was investigated in H-2-incompatible allogeneic mice. The following results were obtained. (a) All the sublines showed increased immunogenicity and susceptibility to lysis as compared to L1210 cells. The number of plaque-forming cells/spleen ranged from 100 for L1210 to 4450 for L1210/GZL, the most immunogenic subline, and the antibody titer ranged from 1/8 for L1210 to 1/128 for L1210/GZL. (b) All the sublines carried common tumor-associated antigens that apparently made primary contributions to the increased immunogenicity. (c) The common tumor-associated antigens were also expressed on L1210 cells, although in a lesser defree, as evidenced by the definite, albeit low, capacity of L1210 cells to absorb DBA/2J anti-L1210/GZL antibodies. (d) Spleen and thymus cells of DBA/2J mice as well as unrelated murine ascites tumor cells did not cause significant absorption of these antibodies. (e) Only a partial inverse relationship could be demonstrated between tumor-associated antigens but the lowest for H-2. The above results would seem compatible with the hypothesis that the increased immunogenicity of drug-resistant L1210 sublines is attributable to the selection of preexisting highly immunogenic cells during immunosuppression by treatments selecting for drug resistance.

Animals↗
PubMed1975

An experimental model for evaluation of factors in tumor escape from immunological attack.

A model system is presented for studying the factors involved in tumor immunity. The initial observations with this system concern the importance of dose and route of administration of tumor cells on tumor growth. The data show that myeloma tumor cells, when inoculated i.v.in relatively large numbers, are eradicated by the immune response of an allogeneic host; tumor cells administered i.v. in smaller number escape from immune attack even though the host has the potential to mount an immune response. BALB/c mouse myeloma cells (MOPC-21) were transplanted s.c., i.p., or i.v. into H-2-compatible allogeneic DBA/ 2 mice. There was a marked difference in the response of the host to tumor given s.c. or i.p. as compared to tumor given i.v. Thus s.c. or i.p. inoculation resulted in lethal tumor growth when 5 x 10-3 or more tumor cells were given. In contrast, the outcome of i.v. inoculation depended on tumor cell dose. Although small cell doses ( 5x 10-4 down to 10-2) resulted in lethal tumor gosulted in lethal tumor growth with only 10% survival, large cell doses (10-5 to 5 x 10-7) resulted in tumor rejection and 70% survival. DBA/2 mice possess the immunological ability to react agaist the tumor when large doses of tumor cells (10-7) are given i.v. or i.p., since spleen cells obtained from such mice were found to be able to suppress the growth of MOPC-21 when a mixture of spleen cells and tumor cells was inoculated. On the basis of these initial observations, our model appears to relate especially to the idea that, in autochithonous tumor development or in metastasis of tumor, a small number of antigenic tumor cells, perhaps even a single cell, usually grows into a frank tumor in spite of the immunological competence od the host to respond to the tumor cells.

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PubMed1973

In vitro studies on strain-dependent production of thymus-specific autoantibodies.

In vitro cultures of spleen cells (S) from normal 8-10-wk-old DBA/2J mice were shown to develop a small number of plaque-forming cells (PFC) that released antibodies lytic to syngenic and autologous thymus cells as well as to syngenic lymphoma L5178Y cells used as the target in the PFC assay. A marked increase in the number of PFC detectable on L5178Y target cells was demonstrated on day 4 in the cultures of S cells to which syngenic or autologous thymus cells had been added (S+T) at time 0, whereas the PFC detectable on thymus cells in such cultures remained at a level similar to that in S cultures. This suggested that two populations of PFC participated in the observed phenomena. No PFC developed in the culture of thymus cells (T). The addition of the cell-free supernatants of 24-h cultures of T or of L5178Y cells to syngenic S cultures also caused a specific increase in the number of the PFC detectable on L5178Y, which suggested that certain immunogenic factors released from the T cells stimulated the response observed in the S+T cultures. Antibodies of IgM nature were detected in the supernatants of S+T cultures by means of cytolysis in agar of L5178Y cells. Although such antibodies did not cause lysis of thymus cells, they could be completely removed by absorption with normal adult or fetal thymus cells of syngenic origin. Still, the absorbing capacity of L5178Y was much higher than that of thymus cells. The absorption was more efficient at 4 degrees C than at 22 degrees C, and hardly any absorption occurred at 37 degrees C. The tissue distribution of the antigen under study seemed to be restricted to thymus cells since no other murine tissue cells tested removed the antibodies. The thymic antigen under study was not restricted to strain DBA/2J and could be demonstrated on thymus cells of all other strains tested. On the other hand, the ability of spleen cells to respond in vitro to this antigen has thus far been observed only in DBA/2J mice. Spleen cells of strains C57BL/6J and NZB/BINJ as well as (DBA/2 x NZB)F(1) failed to show any significant increase in the PFC response detectable on the L5178Y target when syngenic thymus cells or DBA/2J thymus cells were added. An intravenous injection of syngenic thymus cells to DBA/2J mice also caused the appearance in their spleens of PFC detectable on the L5178Y target. The described in vitro system may provide a good means of studying the cellular basis of generation of self-tolerance and of its breakdown.

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