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H Kirchner

Publications and source records attributed to H Kirchner.

At least 469 records · Page 26Linked to original sources
PubMed1976

Suppression of mixed lymphocyte response in mice bearing primary tumors induced by murine sarcoma virus.

Mixed lymphocyte culture (MLC) responses of spleen cells from mice bearing tumors induced by murine sarcoma virus of the Moloney type (MSV) against allogeneic spleen cells were found to be markedly depressed, as estimated by three parameters: lymphoblast counts, 3H-thymidine incorporation (TI), and cell-mediated lysis (CML). While all three parameters were definitely depressed in comparison to the normal controls, TI was depressed to a greater degree than lymphoblast counts and CML. MSV spleen cells also had a suppressive effect on the MLC responses of normal spleen cells in third party type of experiments. The cells mediating this effect were radioresistant non-T cells, which were removed by adherence columns and were inactivated by carrageenan. These data suggested that the supressor cells were macrophages. Serum from MSV tumor-bearing mice had a greater suppressive effect than did normal mouse serum. Both the suppressor cells and the suppressive serum factors may play an important role in the immunosuppression observed in tumor-bearing hosts.

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PubMed1976

Two functionally distinct anti-tumor effector cells isolated from primary murine sarcoma virus-induced tumors.

The ability of cells from primary MSV-induced tumors to function as effector cells in vitro was evaluated. Host cells were isolated by enzymatic disaggregation of the tumor and fractionated by sedimentation velocity at unit gravity on a Ficoll gradient. Characterization of these cells indicated that 30 to 40 % were T lymphocytes, about 50% were macrophages and less than 5% were B lymphocytes. Two different functional activities were mediated by these cells: cytolysis, as measured by the CRA, and inhibition of proliferation, as measured by the GIA. The effector cells in the CRA were T cells with sedimentation velocities of 3.5 to 4.0 mm/hr, whereas those cells which mediated the GIA were presumably macrophages and displayed a heterogeneity in size two peak sedimentation velocities, one at 4.0 mm/hr and another at 6.0 mm/hr. Activity by the effector cells in the CRA was antigen specific in contrast to the activity in the GIA which was directed against cells which did not carry detectable cross-reacting antigens.

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PubMed1976

Replication of herpes simplex virus in mouse spleen cell cultures stimulated by lipopolysaccharide.

Replication of HSV was demonstrated in spleen cell cultures of D2 and several other strains of mice after prestimulation with mitogenic doses of LPS for 2 days. No viral replication occurred in unstimulated cultures or in cultures prestimulated with PHA and Con A, whereas there was some viral replication in spleen cell cultures of D2 mice after prestimulation with Poly I-C. Spleen cells of B6 mice did not support replication of HSV under any of the conditions we have tested thus far. The reasons for this defect are not clear, but it was obviously not caused by a defective lymphoproliferative response to LPS or by an active anti-viral principle elaborated by B6 spleen cells. F1 hybrids between B6 and D2 mice were capable of HSV replication to the same extent as were spleen cells of D2 mice. Several strains of both HSV-1 and HSV-2 could be replicated in D2 spleen cells cultures. Nylon column treatment of D2 spleen cells removed the ability to replicate HSV, whereas macrophage removal from the spleens by plastic adherence was without effect. Purified peritoneal exudate cells from D2 mice did not support replication of HSV. Together these data suggest that B cells activated by LPS represent the target cell of HSV replication in mouse spleen cell cultures.

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PubMed1976

Cell-mediated immunity to Friend virus-induced leukemia. III. Characteristics of secondary cell-mediated cytotoxic response.

By employing the 125IUdR release cytotoxicity assay, we have been able to measure the primary and secondary cell-mediated cytotoxic response of C57BL/6 mice to FBL-3 cells, a syngeneic Friend virus-induced leukemia. It was found that the secondary cell-mediated cytotoxic response occurred more rapidly after challenge (within 3 days) than the primary response, and the levels of reactivity were considerably higher. As in the primary response, the secondary cytotoxic reactivity of spleen cells was T cell dependent, being eliminated by pretreatment with anti-theta antibody plus complement. However, the secondary reactivity of pertioneal exudate (PE) cells was not entirely T-cell dependent. The specificity of the secondary cytotoxic response was analyzed by primary or secondary immunization with various tumor cells and by testing of cytotoxic lymphocytes against a variety of target cells. When spleen cells were used for testing, only tumor cells induced by Friend, Moloney, or Rauscher (FMR) leukemia viruses could produce secondary cell-mediated cytotoxic responses against FBL-3 cells. This correlated well with the specificity observed in the in vivo tumor transplantation protection studies. Similarly, spleen cells immune to FBL-3 had appreciable cytotoxicity against tumor cells induced by FMR viruses. The FBL-3 immune mice also gave significant protection against the challenge of FMR leukemias. When PE cells were used for testing, they gave higher levels of cytotoxicity against tumor cells induced by FMR viruses, but also gave less, but appreciable, cytotoxicity against non-FMR tumors. The latter reactivity might be related to the antigens induced by the murine endogenous type C viruses.

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PubMed1976

Cell-mediated immunity to leukemia virus- and tumor-associated antigens in mice.

Cell-mediated immune reactions appear to play an important role in resistance against growth of leukemia cells in mice. Possible mechanisms for in vivo protection in two tumor systems are discussed. These tumor models, which are a Friend leukemia virus-induced transplantable tumor, FBL-3, and primary murine sarcoma virus (MSV) -induced tumors, are strongly antigenic; under some conditions, tumors regress completely. In mice with regressing FBL-3 tumors, cell-mediated cytotoxicity was measured by release of [125I]iododeoxyuridine. The response was biphasic, with an initial peak at 10 days and a 2nd peak after 30 days. A boost in reactivity could be elicited by later challenge with tumor cells. All of the reactivity was dependent on T-cells, being eliminated by treatment with anti-theta plus complement. The specificity of the reactions was not completely defined, but it was consistent with Friend type-specific antigen plus broader, common antigens. In mice with regressing MSV tumors, strong cell-mediated cytotoxicity, measured mainly by release of 51Cr, was seen against RBL-5, a Rauscher virus-induced leukemia. A single peak of response occurred at about 14 days after virus inoculation. Upon later challenge with RBL-5 cells, a vigorous and rapid secondary response was elicited, mainly in the region of tumor challenge. This cytotoxic reactivity and in vivo resistance to leukemia.lso was completely dependent on T-cells. In addition, macrophage-mediated inhibition of leukemia cell growth in vitro was seen in this system at the time of peak tumor development. The 51Cr release cytotoxicity was specific and directed primarily against an antigen, MEV-SA1, associated with mouse endogenous C-type viruses. The macrophage-induced growth inhibition appeared to be nonspecific. In both the FBL-3 and MSV tumor systems, protection against tumor growth could be adoptively transferred by immune lymphoid cells. In addition to induction of cell-mediated immunity by tumor cell or virus inoculation, cell-mediated cytotoxic reactivity was found to occur naturally in most young mice. This natural killer activity was quite distinct from the experimentally elicited reactions, being mediated by N-cells, a subpopulation of lymphoid cells with no clearly identifiable cell surface markers. The natural cytotoxicity was also directed against antigenic specificities different from those recognized by the MSV-immune cells. The central issue in all of these studies has been to determine the relationships between the in vitro-detected cell-mediated reactivity and in vivo resistance to leukemia.

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PubMed1976

Augmentation of cell-mediated cytotoxicity against syngeneic Gross virus-induced lymphoma in rats by phytohemagglutinin and endotoxin.

Normal W/Fu rat spleen cells cultured for 1 day with mitogenic concentrations of phytohemagglutinin (PHA) or with a wide range of concentrations of endotoxin (LPS) exerted cytotoxic activity against the syngeneic Gross virus-induced lymphoma, (C58NT)D, and also against other tumor cells in a 4-hr 51Cr release assay. This activity did not involve release of detectable lymphotoxins, nor did it require the presence of additional mitogen in the media during the cytotoxicity assay. The cytotoxic activity induced by PHA was dependent on the presence of T cells while the activity induced by LPS was not dependent on T cells and appeared to require the presence of macrophages. Both PHA and LPS also augmented the cytotoxic activity of spleen cells immune against (C58NT)D tumor cells. With submitogenic concentrations of PHA, only specific cytotoxicity against (C58NT)D cells was augmented. In contrast, LPS and mitogenic concentrations of PHA caused nonspecific augmentation. Mitogenic concentrations of PHA and LPS also augmented the antibody-dependent cytotoxicity of normal W/Fu rat spleen cells against (C58NT)D cells in the presence of syngeneic anti-serum.

AKR murine leukemia virus↗
PubMed1975

Inhibition of in vitro lymphoproliferative responses to tumor-associated antigens by suppressor cells from rats bearing progressively growing Gross leukemia virus-induced tumors.

W/Fu rats were injected subcutaneously with low numbers of cells from the Gross leukemia virus-induced lymphoma, (C58NT)D, which induced transient tumor growth and regression (regressors), or with high numbers of tumor cells resulting in progressive tumor growth (progressors). Spleen cells from regressors had a significant reactivity in the mixed leukocyte tumor cell interation (MLTI), while spleen cells from progressors were unresponsive. Similarly, the responses to the non-specific mitogens, phytohemagglutinin and concanavalin A, were suppressed in spleen-cell cultures of progressors. Passage of spleen cells from progressors over rayon adherence columns or pretreatment with an iron/magnet technique resulted in almost complete restoration of MLTI and mitogen responses. Addition of spleen cells from progressors depressed the MLTI of spleen cells from regressors and the mitogen reactivity of normal spleen cells. Serum from progressors also suppressed MLTI and mitogen reactivity. These data indicate that, in spleens of rats bearing progressively growing tumors, suppressor cells can be demonstrated which inhibit specific reactivity to tumor-associated antigens and non-specific reactivity to mitogens. The presence of suppressor cells or of inhibitory factors in the serum may contribute to the immunosuppression frequently observed in tumor-bearing hosts.

AKR murine leukemia virus↗
PubMed1975

Inhibition of in vitro growth of lymphoma cells by macrophages from tumor-bearing mice.

Spleen cells from C57BL/6 mice bearing primary tumors induced by the Moloney strain of murine sarcoma virus (MuSV) strongly inhibited the uptake of tritiated thymidine (3H-TDR) by RBL-5 lymphoma cells in a 48-hour growth-inhibition assay (GIA). This activity was first detected 7 days after MuSV was injected; it peaked at 14 days, and was usually no longer detectable after 18-21 days. It could be detected at effector cell/target cell ratios between 20:1 and 5:1, at which normal spleen cells had a growth-promoting effect. The effector cells in the GIA were not T cells, and various depletion experiments suggested that they were macrophages. Macrophages of a purity of over 95% were obtained in the glass-adherent fraction of thioglycollate-induced peritoneal exudate cells (PEC). PEC were growth inhibitory when obtained from either normal or MuSV tumor-bearing mice. However, at effector cell/target ratios of 2.5:1, only PEC from MuSV tumor-bearing mice had an effect; PEC from normal mice were inactive. Activity of spleen cells in the GIA appeared distinct from T-cell-dependent specific cytotoxicity, which was not affected by removal of macrophages. Activity in the GIA was nonspecific, and target cells which do not cross-react with RBL-5 cells were equally inhibited. Furthermore, spleen cells from mice bearing primary tumors induced by 3-methylcholanthrene were also fully active against RBL-5 cells. Supernatants from spleen cell cultures obtained from mice 14 days post injection with MuSV also inhibited the incorporation of 3H-TDR by RBL-5 cells in vitro. However, this effect seemed to be an artifact, since the tumor cells proliferated equally well in the presence or absence of the supernatants. In contrast, the direct effect of spleen cells from MuSV tumor-bearing mice was reflected both by an inhibition of cell proliferation and by inhibition of 3H-TDR incorporation.

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PubMed1975

Splenic suppressor macrophages induced in mice by injection of Corynebacterium parvum.

Spleen cells from C57BL/6N mice injected with killed Corynebacterium parvum (CP) had a marked growth inhibitory effect on the in vitro proliferation of RBL-5 murine lymphoma cells. It was most marked 12 to 14 days after injection and was usually no longer detectable later than 21 days. It could be demonstrated at effector cell to target ratios between 20:1 and 5:1 at which normal spleen cells had a growth-promoting effect. Addition of CP to an in vitro mixture of spleen cells and tumor cells augmented the inhibitory effect of spleen cells from CP-injected mice although it conferred no inhibitory potential on normal spleen cells. Growth inhibiton by CP spleen cells was not mediated by T cells and various depletion experiments suggested that the effector cells of the phenomenon were macrophages. Spleen cells of CP-injected mice also showed strongly depressed responses to the T cell mitogens PHA and Con A and suppressed the mitogen responses of syngeneic normal spleen cells. The characteristics of the suppressor cells mediating this effect appeared to be very similar to those inhibiting lymphoma cell growth. The responses to LPS were also strongly suppressed in mice injected with 2.1 mg of CP. However, after injection of one-tenth of the dose a relative sparing of the LPS response was noted, whereas the PHA response was still suppressed.

Animals↗
PubMed1975

Inhibition of proliferation of lymphoma cells and T lymphocytes by suppressor cells from spleens of tumor-bearing mice.

We have recently demonstrated suppressor cells in spleens of mice bearing tumors induced by Moloney murine sarcoma virus (MSV) which were non-T cells and inhibited phytohemagglutinin Molney (PHA)-induced DNA synthesis of syngeneic normal spleen cells. From the present study, the suppressor cells appeared to be macrophages since they were radioresistant, inactivated by carrageenan, and removed by adherence columns and an iron/magnet technique. We have also found that suppressor cells were still fully active when added 16 hr after the mitogen, thus indicating that early mitogen-induced changes were not the target of suppressive action. It appeared that suppressor cells inhibited metabolic events related to the initiation of DNA synthesis and that they had a selective effect on proliferation-dependent lymphocyte effector functions. PHA-induced cytotoxic reactivity which in our system is largely independent of DNA synthesis was not depressed but actually enhanced in MSV spleens. Cytotoxicity of MSV spleen cells against syngeneic lymphoma cells was unaffected by suppressor cells whereas lymphocytes stimulation by mitomycin C-treated syngeneic lymphoma cellls was inhibited. MSV spleen cells also inhibited DNA synthesis of cultured murine lymphoma cells. This function was only slightly diminished after treatment with anti-omicron serum plus guinea pig complement. Furthermore, spleen cells from MSV tumor-bearing nude mice were as effective as spleen cells from their heterozygous littermates, thus suggesting that T lymphocytes are not the main effector cells of inhibition of lymphoma cell DNA synthesis. The inhibitor cells were radioresistnant, inactivated by carrageenan, and removed by adherence columns and the iron/magnet technique. These data strongly suggest that the inihibitor cells of lymphoma cell DNA synthesis are macrophages and that they belong to the same group of cells as the suppressor cells of PHA-induced lymphocyte proliferation.

Animals↗
PubMed1975

Secondary cell-mediated cytotoxic response to syngeneic mouse tumor challenge.

When C57BL/6 mice previously immunized with murine sarcoma virus (MSV) were challenged with a Rauscher virus-induced lymphoma, RBL-5, a secondary cell-mediated cytotoxic response could be detected by the Cr release cytotoxicity assay. The level and distribution of the secondary cytotoxic response was affected by the route of challenge. Animals injected i.p. demonstrated a high level of cytotoxicity in the peritoneal exudate cells 3 days after challenge and subsequently cytotoxicity was detected in most lymphoid organs, although at lower levels. However, when the animals were challenged intramuscularly in the leg, the response was not detected as rapidly and furthermore cytotoxic lymphocytes were found only in the draining lymph node and not in other lymphoid organs. Treatment of the effector cells with anti-theta and complement showed the secondary response to be predominately dependent on T cells. In addition, the cytotoxicity was specific in that cells lacking cross-reacting antigens were not killed by these attacker cells from mice undergoing a secondary response.

Animals↗
PubMed1974

Evidence of suppressor cell activity in spleens of mice bearing primary tumors induced by Moloney sarcoma virus.

Spleens from Moloney sarcoma virus (MSV) tumor-bearing C57BL/6N mice contained four times the normal number of mononuclear cells and displayed a markedly elevated "spontaneous" (mitogen-independent) DNA synthesis on a per cell basis. The number of macrophages were increased three-fold while there was a slight reduction in the percentage of T lymphocytes. The phytohemagglutinin (PHA) response on a per cell basis of spleens from tumor-bearing mice was decreased about 90% when compared with normal control mice. The primary in vitro immune response to sheep red blood cells was also suppressed to levels of less than 10% of normals. The PHA response could be restored by purification of MSV spleen cells by rayon adherence columns and by removal of phagocytic cells by an iron/magnet technique. The activity of suppressor cells in MSV spleens was demonstrated in mixtures with syngeneic normal spleen cells where a marked impairment of the PHA response was observed. Spleen cells from tumor-free nude mice and normal spleen cells treated by anti-theta serum plus guinea pig complement (C'), both totally unreactive to PHA, had no such effect. The inhibitor cell in MSV spleens was shown to be insensitive to inactivation by anti-theta plus C', but could be removed by the adherence columns and the iron/magnet technique. These data suggest that this suppressor cell is a cell of the monocyte/macrophage series. Suggestive evidence was also presented that the suppressor cells belong to a proliferating population in MSV spleens. Similar suppressor cells have been previously demonstrated in spleens of mice during a variety of immune responses. Our data show, that a tumor, although stimulating the immune system, nevertheless may be suppressive on certain immune functions through the activation of suppressor cells.

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