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Biomedical subjects

G Parmiani

Publications and source records attributed to G Parmiani.

At least 271 records · Page 15Linked to original sources
PubMed1979

Biochemical characterization of alien H-2 antigens expressed on a methylcholanthrene-induced tumor.

A methylcholanthrene-induced tumor of BALB/c (H-2d) origin had been shown to express H-2 antigens normally associated with the H-2k haplotype. The molecules expressing the alien antigens have been partially purified and shown to be distinct from molecules expressing normal H-2d antigens. Like normal H-2 antigens, the alien antigens have a molecular weight of 48,000, are glycoproteins, and are noncovalently bound to beta 2-microglobulin. The alien antigens differ from normal H-2 antigens in their susceptibility to papain digestion, behavior during gel filtration, and overall stability. Possible mechanisms accounting for the expression of the alien antigen are discussed.

Animals↗
PubMed1977

Multiple foreign non-H-2 determinants on the surface of a chemically-induced murine sarcoma.

By immunizing BALF/c (H-2d) mice against normal tissues from C57BL/6J (H-2d), C3Hf (H-2k) and DBA/2 (H-2d), but not from AKR (H-2k) strains, resistance was induced to the subsequent challenge of the 'syngeneic' methyl-cholanthrene-induced BALB/c sarcoma ST5; lymph node cells from alloimmune BALB/c mice were also able to exert a parallel cytotoxic effect against in vitro cultured ST5 cells. The involvement of foreign H-2 specificities in the observed cross-reactions was ruled out by absorption of H-2 monospecific sera and by the interallelic combinations used, thus suggesting that non-H-2 histocompatibility antigens were responsible for the above findings. By using the indirect isotopic antiglobulin assay, BALF/c anti-C57BL/6J and anti-C3Hf polyspecific sera were found to bind specifically to cultured ST5 cells. C57BL/6J and C3Hf, but not DBA/2, lymph node cells were able to absorb the anti-ST5 activity of the anti-C57BL/6J serum. These results indicated that ST5 cells expressed on their surface at least two different sets of foreign non-H-2 antigens: one shared by C57BL/6J and C3Hf tissues, and detected by both cell-mediated and serological techniques; the other one belonging to DBA/2 tissues, and revealed mainly at the cell-mediated level.

Animals↗
PubMed1975

Alien histocompatibility determinants on the cell surface of sarcomas induced by methylcholanthrene. I. In vivo studies.

Groups of BALB/c mice were immunized to normal tissues (skin and/or liver plus kidney) of C3Hf, C57Bl/6, DBA/2 and AKR strains and challenged with either of two syngeneic 3-methylcholanthrene-induced immunogenic sarcomas, ST2 and TZ15, or with a "spontaneous" non-immunogenic BALB/c sarcoma, B2. It was found that anti-C3Hf and anti-DBA/2 immune mice were significantly protected against the growth of ST2, whereas anti-AKR immune mice rejected TZ15; no protection was elicited by immunizing with normal tissues of any strain against B2, which lacked individual tumor-associated transplantation antigens (TATA). The reciprocal experiment, i.e. the immunization of BALB/c mice with tumor cells and challenge with skin grafts of different strains, was also carried out with ST2 and TZ15. Accelerated rejection of all the various allogeneic skins was observed in anti-ST2 immune mice and of AKR and C3Hf skin in anti-TZ15 immune animals. In addition the Winn test demonstrated that lymph-node cells of BALB/c mice immune to C3Hf or DBA/2 tissues were specifically inhibitory for ST2, and that lymph-node cells immune to AKR tissues protected against TZ15. In a further experiment both ST2 and TZ15 tumors were left to grow in (C3Hf X BALB/c)F1, (C57Bl/6 X BALB/c)F1, (BALB/c X DBA/2)F1 and (BALB/c X AKR)F1 mice; the tumors were then excised and the "immune" mice challenged with the related tumor to measure their immune response in comparison with that elicited by the same procedure in BALB/c mice. ST2 was highly immunogenic in syngeneic BALB/c mice and in all the hybrid combinations except (C3Hf X BALB/c)F1 mice, where it completely lost its immunogenicity; TZ15 showed a certain loss of immunogenic strength in (BALB/c X AKR)F1 hybrids. It was concluded that TATA of ST2 contain antigenic determinants expressed on the normal cells of C3Hf and DBA/2 strains, and that TATA of TZ15 are likely to share antigens with AKR normal tissues.

Animals↗
PubMed1975

Nonimmunogenic sarcomas induced by 3-methylcholanthrene treatment of murine fibroblasts in diffusion chambers.

A 30-mug dose of 3-methylcholanthrene (MCA) was applied for 1 week to normal BALB/c fibroblasts in cell-impermeable diffusion chambers (DC) in the peritoneal cavities of BALB/c micemtwo groups of DC cultures, in which the carcinogen was given during weeks 1 and 5 of cultivation, respectively, were compared for the frequency of malignant transformation and for the immunogenicity of the resulting neoplasms. The cells from each DC were transplanted sc into immunodepressed semisyngeneic mice for assay of their tumorigenicity. Although tumor yield was similar in the 2 groups (25 and 22%, respectively), there was clear difference in immunogenicity; 10 of 16 sarcomas from fibroblasts treated during week 1 of culture were nonimmunogenic, whereas 8 of 9 tumors from the older cultures were immunogenic (P less than 0.02). A kinetic study of normal fibroblasts in DC revealed that cells proliferated rapidly, with a peak at day 4 after seeding, then grew progressively more slowly and ceased to replicate between 14 and 28 days of culture. Thus there was a notable difference at the moment of MCA application in the growth phase of the target cell population of the first as compared with the fifth week of culture, possible related to the different expression of tumor-associated transplantation antigens in the resulting neoplasms.

Animals↗
PubMed1975

Depression of cellular immune response during syngeneic pregnancy as measured by the graft-versus-host reaction.

The cellular immune response during the course of intrastrain pregnancies was evaluated in primiparous and multiparous BALB/c females by the graft-versus-host (GVH) activity of the splenic and lymph nodal lymphocytes. Splenic lymphocytes of both primiparous and multiparous pregnant mice had a GVH activity lower than that of the virgin mice. This immune deficit was more evident in multiparous than in primiparous females and occurred at the 6th day and during the last week of pregnancy. A similar although less pronounced phenomenon was found when lymph nodes instead of spleen of multiparous females were used at the source of cells in GVH reaction. The immune deficit was less marked when spleen and lymph node cells of pregnant mice were compared with similar cells of pseudopregnant females. Incubation of virgin BALB/c spleen lymphocytes in the serum of multiparous pregnant mice as compared to normal virgin serum caused a reduction of the GVH activity; incubation of the cells in pseudopregnant serum also inhibited the immune response, but to a lesser extent than the incubation in multiparous sera.

Animals↗
PubMed1971

Immunodepression during urethane and N-nitrosomethylurea leukaemogenesis in mice.

Five injections of urethane, 1 mg./g. body weight to suckling mice markedly reduced the primary immune response against sheep red blood cells assessed by splenic plaque forming cells (PFC) determination and haemagglutinin (HA) titration. The immunological impairment lasted for about 50 days after the end of the treatment. The secondary response tested by HA titration was not affected. A lower dose of urethane (0.5 mg./g.) produced only a delay of the primary HA response. A single neonatal dose of N-nitrosomethylurea (NMU) caused a profound immunodepression evaluated as HA titre and number of PFC. Both primary and secondary responses were still depressed when tested at 50 and 90 days of age respectively. No clear correlation between the degree of immunodepression and lymphoma development was found.

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