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G Parmiani

Publications and source records attributed to G Parmiani.

At least 235 records · Page 13Linked to original sources
PubMed1985

Cell surface antigens of chemically induced fibrosarcomas: detection by a monoclonal antibody of a tumor-restricted Mr 12,000 protein gag antigen encoded by a dual-tropic murine leukemia virus.

Fusion products of spleen cells of W/FuDp rats immunized with a methylcholanthrene-induced BALB/c sarcoma, CA-2, and mouse myeloma cells were screened in an attempt to identify a monoclonal antibody defining the individually distinct tumor-specific transplantation antigen of CA-2. A hybridoma, MP/69/04, was isolated which produces an IgG2a monoclonal antibody that recognized a tumor-restricted antigen of CA-2. In direct binding assay, MP/69/04 reacted only with 2 of 15 methylcholanthrene induced BALB/c sarcomas tested. Thymus, spleen, lymph nodes, bone marrow, brain, adult lung fibroblasts, newborn muscle fibroblasts and 3T3 cells were negative. Absorption tests revealed, however, expression of the MP/69/04 determinant on 8 of the 12 murine leukemia virus (MuLV) producer BALB/c sarcoma tested. The antigen was not detected on any of the three non-producer sarcomas tested nor on a wide range of normal tissues and cell lines. An N-dualtropic MuLV was isolated from CA-2, and cell lines susceptible to infection by this virus were shown to express the MP/69/04 epitope. By Western blotting, the MP/69/04 epitope was identified as being expressed on the MuLV structural protein with a molecular weight of 12,000, present in CA-2 cells and in the purified CA-2 MuLV. These results indicate the MP/69/04 antigen is not a unique tumor-specific transplantation antigen but is a gag product of a recombinant retrovirus which is expressed on the cell surface of many MuLV + methylcholanthrene-induced BALB/c fibrosarcomas.

Animals↗
PubMed1985

In vivo reexpression of H-2 antigens in B16 melanoma cells.

We have previously shown that B16-A (H-2b) murine melanoma cells, when cultured in vitro for more than ten passages, have an undetectable or reduced expression of H-2Kb and Db antigens, respectively. We have now studied the possibility to restore H-2 expression (measured by quantitative antisera absorption) in B16-A cells either by a limited (30 days) period of in vivo growth or by treatment with immune interferon. In vivo transplants in allogeneic H-2k or H-2d mice and in H-2-compatible but Mls and multiple non-H-2 loci incompatible mice restored the normal expression of Kb and Db antigens. Cells obtained from tumors grown in syngeneic or in minor histocompatibility antigens-allogeneic mice showed only a weak increase in Db antigens. Such induction of H-2 expression appears to be mediated by the host's immune system, since (1) cells obtained from tumors grown in allogeneic BALB/c nude mice expressed much lower levels of H-2 antigens than those from tumors grown in normal BALB/c mice, and (2) it was possible to induce H-2 expression by growing B16 cells in syngeneic C57Bl/6 mice previously allostimulated with unrelated BALB/c tumor. In vitro treatment with immune interferon restored the expression of both Kb and Db antigens. We hypothesize that H-2 reexpression on B16 cells grown in allogeneic hosts could take place via the nonspecific components of the immune response, such as immune interferon.

Animals↗
PubMed1985

NMU-1, a new transplantable mouse lung tumor: biological and chemosensitivity properties in vivo.

NMU-1 is a lung adenocarcinoma induced by N-nitroso-N-methyl-urea in a BALB/c Lac Dp mouse and maintained in vivo by sc passages of tumor fragments. No spontaneous regressions have been observed. After sc implantation, NMU-1 metastasizes to the lung as shown by a bioassay. Seven established antitumoral drugs were used to evaluate the chemosensitivity of this neoplasm. Mitomycin, cyclophosphamide, and cisplatin statistically affected tumor growth, as evaluated by three end points (ie, tumor weight, increase in lifespan, and tumor growth delay). 5-FU, doxorubicin, and vincristine showed significant activity on two end points. Carmustine did not affect any end points.

Adenocarcinoma↗
PubMed1984

The inhibition of lymphocyte stimulation by autologous human metastatic melanoma cells correlates with the expression of HLA-DR antigens on the tumor cells.

Previous studies indicated that peripheral blood lymphocytes from patients (Pt-PBL) with lymph node metastatic melanomas proliferated in vitro and developed into tumor-restricted cytotoxic lymphocytes in response to alloantigens or interleukin 2 (IL-2). However, Pt-PBL were not stimulated by irradiated autologous metastatic melanoma (Auto-Me) cells. In the present study we report that the lack of stimulatory activity of Auto-Me cells may be due to a suppressive effect exerted by Auto-Me cells on the responder lymphocytes. In fact, we found that in 62% of cases examined, the addition of 5-10% Auto-Me cells to Pt-PBL cultures strongly inhibited both proliferation and the generation of tumor cytotoxic lymphocytes induced by alloantigens or IL-2. The inhibition was dose-dependent and tumor-restricted, and was not due either to toxicity, medium depletion or IL-2 absorption by Auto-Me cells. Normal fibroblasts, K562 cells and autologous E-lymphocytes were not suppressive. Auto-Me cells were able to inhibit Pt-PBL responses only when added during the first 24 h of culture and not later. Phenotypic analysis of Auto-Me cells using monoclonal antibodies directed against HLA-A,B,C, HLA-DR and melanoma-associated antigens revealed that the expression of high levels of DR antigens on Auto-Me cells was associated with an elevated suppressive activity. Conversely, Auto-Me cells with low or undetectable levels of DR antigens were not inhibitory. Furthermore, the increased expression of DR antigens on Auto-Me cells obtained by in vitro treatment with human interferon gamma (IFN-gamma) also resulted in an increased suppressive activity. We conclude that HLA-DR+ metastatic melanoma cells can interfere with the generation of an anti-tumor immune response, thus potentially favoring the escape of the tumor from the host's control mechanism.

HLA-DR Antigens↗
PubMed1984

Passive adoptive immunotherapy of low-immunogenic BALB/c lymphoma by syngeneic alloimmune T lymphocytes.

The virus-induced BALB/c lymphoma YC8 is known to be lysed in vitro by syngeneic lymphoid cells immune to non-H-2 antigens of B10.D2 and DBA/2 backgrounds. This tumor is weakly immunogenic in vivo and kills 100% of syngeneic mice with 1 X 10(3) cells given either intravenously (i.v.) or intraperitoneally (i.p.). We show here that i.v.-injected YC8 cells grow preferentially in the liver, where colonies become microscopically visible after 7-10 days, and, less frequently, in the kidneys and spleen but not in the lung. Passive adoptive immunotherapy of this tumor was carried out with alloimmune BALB/c anti-B10.A, anti-pool (donors were immunized with lymphocytes from 5 different strains), anti-A and anti-DBA/2 splenic and lymph node cells. When administered i.p. 1, 3 or 5 days after tumor cells had been given i.p. and with a schedule of 5 subsequent daily inocula, anti-DBA/2 lymphocytes cured 100%, 80% and 60% of animals respectively. A weaker effect was obtained with anti-pool immune cells whereas anti-B10.A and anti-A lymphoid cells had not therapeutic effects. When given i.v., the anti-DBA/2 immune lymphocytes were able to cure both i.v. and i.p. tumor-injected mice. A significant effect was observed also when the onset of immunotherapy was delayed until 7 or 10 days after tumor injection. By depleting the BALB/c anti-DBA/2 immune cells with appropriate monoclonal antibodies and complement, it was found that Lyt 1+ 2-cells played the major role in eradicating the neoplasm. in vitro phenotypic and functional analysis showed that the immune cell population included 70% of Thy 1+, 38% of Lyt 1+ and 18-20% of Lyt 2+ cells. Immune lymphocytes were not cytotoxic in vitro to YC8 or DBA/2 targets whereas they proliferated after restimulation with DBA/2 but only weakly with YC8 cells. This shows that it is possible to cure mice bearing a disseminated lymphoma which expresses non-immunogenic antigens recognized by BALB/c anti-DBA/2 immune T lymphocytes. These immune lymphocytes had no cytotoxic activity in vitro and their major effector cell subpopulation displayed the Thy 1+, Lyt 1+ phenotype.

Animals↗
PubMed1984

Primary but not metastatic human melanomas expressing DR antigens stimulate autologous lymphocytes.

Lymphocytes from melanoma patients were stimulated in mixed culture with autologous tumor cells (MLTC) in order to evaluate lymphocyte proliferation and subsequent cytotoxicity on autologous melanoma cells. It was found that melanoma cells from lymph node metastases were unable to induce autologous tumor-cytotoxic cells in 21 cases examined, in 15 of which MLTC also failed to induce lymphocyte proliferation. Patients' lymphocytes, however, were significantly stimulated by allogeneic irradiated lymphocytes and by interleukin 2. To investigate whether the lack of autologous stimulation was restricted to metastatic cells, the immune response of patients with only primary lesions of malignant melanoma was evaluated. It was found that primary melanoma cells were able to induce proliferation in 7 out of 9 (77%) patients, whereas positive cytotoxicity was obtained in 2 out of 4 patients tested. In order to see whether the presence of DR molecules was important for the stimulatory activity, melanoma cells were examined for the expression of DR antigens by indirect immunofluorescence with monoclonal antibodies. Positive autologous MLTC was found in all of six DR+ primary melanomas, whereas the two DR-tumors were unable to stimulate autologous lymphocytes. An anti-DR but not an anti-DC monoclonal antibody was able to block the proliferation of lymphocytes induced by an autologous primary melanoma. Neither MLTC nor cell-mediated killing was obtained with either DR+ or DR-metastatic melanoma. In 60% of the cases tested, however, DR+ metastatic melanoma cells were able to stimulate allogeneic lymphocytes of normal individuals. Increased expression of DR antigens was induced by in vitro treatment with human gamma-interferon in metastatic tumor cells; this caused an increase in the proliferation of allogeneic but not autologous lymphocytes. These findings indicate that primary but not metastatic DR+ melanoma cells are able to activate the proliferation and cytotoxicity of autologous peripheral blood lymphocytes, suggesting a potential role of DR antigens in regulating tumor-host relationships in melanoma patients.

Cytotoxicity, Immunologic↗
PubMed1984

Inhibition of human melanoma growth in nude mice by autologous, alloactivated peripheral blood lymphocytes.

Peripheral blood lymphocytes of melanoma patients were stimulated in vitro by a pool of allogeneic lymphocytes and shown to be cytotoxic against autologous melanoma cells. To evaluate the in vivo antitumor activity of the cytotoxic alloactivated autologous peripheral blood lymphocytes, tumor neutralization (Winn) assay was carried out by injecting such lymphocytes admixed with autologous melanoma cells in athymic BALB/c nude mice. In 3 of 6 cases, complete inhibition of tumor growth was obtained at lymphocytes to tumor cells ratio of 10:1 and in one case also of 5:1. In all cases the appearance of tumors was delayed and the growth rate was significantly reduced in a dose-dependent fashion as compared to control mice injected with tumor cells alone. We conclude that in vitro alloactivated peripheral blood lymphocytes can inhibit and/or impair the growth of autologous melanoma cells in nude mice.

Animals↗
PubMed1984

Alien antigens on tumour cells revisited.

New findings on the detection of alien histocompatibility antigens (AHA) on tumour cells are reviewed. Three points are discussed, namely: (1) isolation and molecular characterization of AHA; (2) frequency of expression of AHA by tumour cells, and (3) mechanisms of expression of AHA. Mechanisms of expressions of AHA are particularly discussed in the light of the recent advances in the understanding of the molecular genetic organization of H-2 antigens. Gene conversion involving coding or non-coding sequences might be responsible for the appearance of unexpected H-2 determinants on cancer cells.

Animals↗
PubMed1984

Ly-5 molecular forms in congenitally immunodeficient mice.

Four different molecular weight forms of the Ly-5 antigen were defined by immunochemical methods on the cell surface of murine spleen cells using a monoclonal antibody. Each form was selectively expressed by cells belonging to different lineages. A 220,000-dalton molecule was associated with B cells, a 200,000-dalton molecule with macrophages and two antigens of 185,000 and 175,000 daltons, respectively, were detected on the cell surface of normal thymocytes. The 185,000-dalton Ly-5 molecule was not found on the lymphoid cells of immunodeficient mice, like the athymic nude or the athymic-asplenic (LASAT) mice, suggesting that cells bearing this Ly-5 molecule have a significant function in some T-dependent immune responses.

Animals↗
PubMed1983

In vitro detection of cell-mediated immunity to individual tumor-specific antigens of chemically induced BALB/c fibrosarcomas.

In this study we have analyzed the in vitro cell-mediated cytotoxicity of immune peritoneal exudate cells (PEC), elicited in syngeneic mice against the MCA-induced, TSTA-bearing BALB/c fibrosarcoma CA-2, GI-17 and C-3. The 4 h 51Cr-release assay showed the immune PEC effectors to be specifically cytotoxic to fibrosarcoma used for the immunization, but not to other syngeneic MCA-induced tumors or normal fibroblasts. Cold target inhibition experiments on CA-2 cells confirmed the specificity of the reaction. When PEC, lymph-node and spleen cells from BALB/c anti-CA-2 mice were compared for anti-tumor activity, only PEC were found to kill tumor cells significantly. PEC effectors did not have a significant level of NK or NC activities since they were unable to destroy YAC-1 or WEHI-164 tumor cells. PEC anti-CA-2 were analyzed for the expression of T-cell markers by anti-Thy 1.2, anti-Ly 1.2 and Ly 2.2 monoclonal antibodies. Anti-tumor specific effector cells were identified as mature T cells since they were not adherent to plastic and showed Thy 1.2+, Ly 1.2- and Ly 2.2+ phenotypes. In addition, anti-H-2Kd but not anti-H-2Dd alloantiserum added to target cells, blocked CA-2 tumor lysis, thus supporting the conclusion that the T-cell response against TSTA is H-2 restricted.

Animals↗
PubMed1983

Expression of H-2 and viral antigens and resistance to the antitumor lysis of tunicamycin-treated MBL-2 lymphoma cells.

The role of protein glycosylation in the tumor lysis mediated by effector cells derived from Moloney-sarcoma-virus(MSV)-immune mice was studied. Treatment of the Moloney-virus-induced H-2b lymphoma target cells, MBL-2, with tunicamycin (TM), an inhibitor of the protein-N-linked glycosilation, was found to cause a loss of susceptibility to lysis by MSV-immune syngeneic effectors cells, while the same target cells remained fully sensitive to the lytic action of anti-H-2b-immune lymphocytes. Examination of MBL-2 cell surface by lactoperoxidase, 125I iodination, and immunoprecipitation by antiviral protein sera revealed that env but not gag viral gene-encoded products were expressed on the surface of this lymphoma. The TM-induced alteration of cell surface expression of H-2Db, H-2Kb, and gp70 antigens was examined by a combined approach of serological and biochemical techniques. The results were concordant in indicating that (1) after 16 h of TM treatment the cells showed a decreased expression of the three glycoproteins, (2) H-2Db (the restriction element in this system) resulted more affected by the treatment than its counterpart H-2Kb (75% vs 50% reduction as compared to untreated cells), (3) an additional lighter form of H-2Kb was found on the surface of TM-treated cells. In the context of an "associative recognition' of Db and gp70 by MSV-immune effector cells, our results may explain the loss of susceptibility to antitumor effectors of TM-treated MBL-2 cells by a quantitative reduction in the expression of both molecules which interact to create the target structure of syngeneic effectors.

Animals↗
PubMed1983

Impaired H-2 expression in B16 melanoma variants.

We studied the expression of H-2b alloantigens in three different B16 melanoma lines cultures in vitro. Cell lines were B16-F1 and two cell cultures (named B16-A and B16-B) newly derived from two different in vivo sublines of B16 melanoma. The assays used were in vivo tumour growth in allogeneic (BALB/c and B10.BR) as compared to syngeneic mice, in vitro cell-mediated cytotoxicity by anti-H-2b immune lymphocytes and absorption of anti-H-2b antisera activity. The B16-F1 line was able to efficiently kill allogeneic hosts, could not be lysed by anti-H-2b cytotoxic effectors and did not express any serologically detectable amount of H-2b alloantigens. The B16-A line was H-2 positive during the early in vitro passages, then, at the 8th-10th passages, it acquired the capacity to kill allogeneic hosts, lost the sensitivity to anti-H-2b cytotoxic effectors and the H-2Kb antigens became undetectable The expression of H-2Db was reduced, although at a lower degree. Similar data were obtained with B16-B cells, which after 10 in vitro passages grew and killed allogeneic hosts, showed a decreased sensitivity to cytotoxic anti-H-2b effectors and a very low expression of the K region antigens. The results indicate that H-2 expression is altered in B16 melanoma lines and this may influence the different metastatic capacity of such cells.

Animals↗
PubMed1983

H-2K restriction of the T cell-mediated lysis of a chemically-induced BALB/c fibrosarcoma.

Previous work has shown that a cytotoxic T lymphocyte (CTL) immune response of syngeneic mice immunized with a chemically-induced BALB/c (H-2d) fibrosarcoma was directed against an individual tumour-associated antigen. To see whether this reaction was restricted by products of the major histocompatibility complex (MHC), anti-H-2 alloantisera to K or D antigens were used to interfere with the CTL-mediated immune response. Antisera to Kd but not to Dd antigens inhibited the lytic activity of CTL against fibrosarcoma cells. In addition, the study of the CTL response in F1 leads to P antitumour immunized chimeric mice showed that antitumour cytotoxicity developed only when F1 and parental host shared the Kd region. Both experiments strongly indicate that recognition of the individual tumour-associated antigen of the BALB/c fibrosarcoma is restricted by the products of H-2Kd genes.

Animals↗
PubMed1983

Lack of H-2Ld locus products on a BALB/c fibrosarcoma expressing H-2k-like alien antigens.

The presence of H-2Ld antigens was evaluated in methylcholanthrene-induced BALB/c fibrosarcomas by a variety of approaches. Transplantation experiments showed that BALB/c-H-2dm2 mice, a mutant strain whose cells do not express H-2Ld antigens, after immunization with BALB/c normal tissues developed a resistance to the growth of two tumours (C-3 and GI-17), but not to a third neoplasm, C-1, which is known to have H-2d- as well as H-2k-like alien antigens. In vitro experiments with cytotoxic T lymphocytes generated against Ld antigens confirmed a loss of Ld antigens on C-1 but not on C-3 tumour cells. Serological experiments with an anti-Ld serum again revealed the presence of H-2Ld determinants on C-3 but not on C-1 cells. Biochemical analysis in SDS-PAGE of immunoprecipitates obtained by specific anti-H-2 sera with NP40 lysates of the tumours studied could detect H-2Kd, H-2Dd and H-2Ld antigens in C-3 fibrosarcoma cells whereas Kd and Dd were the only H-2d molecules found in C-1 lysate along with the H-2k-like specificities. The possible genetic mechanisms which may explain this apparent gain and loss modification of the H-2 profile of C-1 are discussed.

Animals↗
PubMed1983

Alloreactivity and tumor antigens: generation of syngeneic antilymphoma killer lymphocytes by alloimmunization of mice with normal cells.

The possibility of obtaining a syngeneic antitumor effect by immunization with normal allogeneic cells was investigated by tests of the lytic activity of peritoneal exudate cells (PEC) of BALB/c mice immunized with lymphoid cells of either a single strain or a pool of six different allogeneic strains on the syngeneic Moloney virus-induced lymphoma YC8 target and on one of its clones designated YC8-D1. Significant cytotoxicity on both targets but not on two other BALB/c lymphomas was obtained with PEC of BALB/c mice singly immunized to the non-H-2-incompatible but H-2-compatible DBA/2 or B10.D2 lymphoid cells. The lack of lysis of YC8 cells by PEC of BALB/c mice immune to B10.A (H-2k,d) suggests that the in vitro killing was restricted by Kd-IEd region products of the major histocompatibility complex. Pool immunization was effective in generating antitumor cytotoxic lymphocytes only when DBA/2 lymphoid cells were included in the pool. The pattern of reactivity of effectors elicited in (BALB/c x DBA/2)F1 and in (BALB/c x B10.D2)F1 mice by immunization with DBA/2 and B10.D2 cells showed that at least two sets of antigens are recognized on YC8 targets, one shared by DBA/2 and B10.D2 tissues and the other expressed by DBA/2 cells only. Cold target blocking experiments indicated that the same effectors recognized non-H-2 antigens of DBA/2 and the cross-reacting YC8 determinants. The antitumor effect was mediated by T-cells, since it was abrogated by treatment of effectors with anti-Thy 1.2 serum plus complement. These data indicate that determinants defined by cytotoxic T-lymphocytes are expressed on the BALB/c lymphoma YC8 and cross-react with non-H-2 antigens of DBA/2 and B10.D2 strains.

Animals↗