asialo-gm1-ganglioside and Lymphoma

Treatment of Swiss albino mice with histamine enhanced the clearance of natural killer (NK)-cell sensitive YAC-1 lymphoma and B16/F10 melanoma cells from lung tissue in vivo, but did not affect the elimination of NK-cell-insensitive P815 mastocytoma cells. The effect of histamine was apparently mediated by H2-type histamine receptors (H2R) since it was blocked by ranitidine, and H2R antagonist. Histamine did not affect clearance of tumour cells in animals depleted of NK cells in vivo by treatment with antibodies to asialo-GM1 or NK1.1. The effect of histamine was time-dependent: pretreatment with histamine for 3 h significantly augmented the clearance of YAC-1 cells, whereas, pretreatment with histamine for 5 min was ineffective. Histamine potentiated the anti-tumour properties of NK-cell activators such as interleukin-2 (IL-2) or interferon-alpha (IFN-alpha) in vivo. None of these lymphokines significantly affected the clearance of YAC-1 cells unless animals were concomitantly treated with histamine. Treatment with ranitidine alone reduced the in vivo clearance of YAC-1 cells from lungs but did not affect the clearance of NK-cell-insensitive P815 cells. Effects of ranitidine on NK-cell function in vivo were not shared by a chemical control to ranitidine, AH20239AA, thus indicating that the inhibition of NK-cells results from H2R antagonism rather than non-specific toxicity. It is concluded that histaminergic mechanisms may be involved in the regulation of NK cell function in vivo.

Topics: Animals; Antibodies; Cytotoxicity, Immunologic; Female; G(M1) Ganglioside; Histamine; Histamine H2 Antagonists; Immunity, Cellular; Interferon-alpha; Interleukin-2; Killer Cells, Natural; Lung Neoplasms; Lymphoma; Melanoma, Experimental; Mice; Ranitidine; Receptors, Histamine H2

We studied the effect of a tilorone analogue (RMI 10,874DA) and anti-asialo GM(1) serum on the survival of BALB/c and C57B1/6 mice after i.v. injections of different syngeneic murine tumour cells. Tumour lines used were different clones from chemically (GR9 wild type, GR9.B9, B7.1.B4, B7.1.B5, B7.2.38), and ultraviolet light (GRUV3)-induced sarcomas; B16 melanoma and LSTRA and YC8 lymphomas. Pretreatment of mice with tilorone inhibited metastatic colonization and increased survival significantly in all cases. In some tumour systems, the effect was attenuated when high numbers of cells were injected. Abrogation of NK cells with anti-asialo GM(1) serum significantly decreased (in all tumours and at different cell doses) survival in comparison with untreated mice injected with tumours, regardless of cell dose used. These results clearly suggest that NK cell activation in vivo by the tilorone analogue we tested prolongs survival and inhibits metastasis formation in mice, even when pretreatment consists of a single dose of the analogue.

Topics: Adjuvants, Immunologic; Animals; Antigens, Neoplasm; Antineoplastic Agents; G(M1) Ganglioside; Histocompatibility Antigens Class I; Killer Cells, Natural; Lymphatic Metastasis; Lymphocyte Activation; Lymphoma; Melanoma, Experimental; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Neoplasm Transplantation; Neoplasms, Experimental; Sensitivity and Specificity; Spleen; Tilorone; Xanthenes; Xanthones

Innovations in methods of combined administration with other BRM or chemotherapeutic drugs have been discussed. We have reported that combined administration with recombinant interleukin-2 (rIL-2) and sizofiran (SPG) is effective in prolonging survival time of C57BL/6 mice intraperitoneally inoculated with EL-4 lymphoma. The immunomechanisms of the combined administration were clarified investigating the intraperitoneal cell population in the primary tumor site, especially the tumor infiltrating lymphocyte (TIL) quantitatively. In the present study, to clarify the antitumor effects of combined administration with rIL-2 and SPG on the metastatic sites, the immunomechanisms of the suppressive effects of combined administration on the metastasis were studied in EL-4 lymphoma cells intraperitoneally transplanted to mice. Inasmuch as EL-4 lymphoma shows rapid hepatosplenic metastasis, we studied the metastatic foci in the liver and the spleen semiquantitatively in investigating the histopathological and immunohistochemical findings of the metastatic foci, especially the TIL. The metastatic foci were stained by hematoxylin-eosin (HE) and monoclonal antibodies (L3T4, Lyt2, asialo GM1, Mac-1, and Ia). The combined administration resulted in: 1) fewer infiltrating tumor cells, 2) more lymphocytic infiltration, and 3) more antitumor effector cells (cytotoxic T cells: Lyt2 and natural killer cells: asialo GM1), macrophages (Mac-1), helper T cells (L3T4), and cells with MHC-class-II antigen (Ia) than did administration of rIL-2 alone or SPG alone, or no administration of these two at all. Combined administration with rIL-2 and SPG appears to activate antitumor-immune response at the metastatic site more effectively than when either agent is administered alone.

Topics: Animals; Antibodies, Monoclonal; Antineoplastic Combined Chemotherapy Protocols; Female; G(M1) Ganglioside; Immunohistochemistry; Interleukin-2; Liver; Lymphoma; Mice; Mice, Inbred C57BL; Neoplasm Metastasis; Recombinant Proteins; Sizofiran; Spleen

Injection of syngeneic lymphoma cells in AKR mice, resulted in an important increase of splenic natural killer (NK) activity in the early days following the graft. Modifications of the production of different types of cytokine: interferon, interleukins 1 and 2, tumor necrosis factor (IFN, IL-1, IL-2, TNF), involved in the regulation of NK activity, were investigated in short-term cultures of total, adherent and non-adherent fractionated spleen cells, using lipopolysaccharide as the triggering or amplifying agent. Upon stimulation with lipopolysaccharide, splenocytes from lymphoma-grafted mice released a large amount of interferon as compared to controls with a maximum level 1 day after the graft. Equal amounts of IFN-gamma and IFN-alpha/beta were detected. Treatment of spleen cells prior to culture with anti-(asialo-GM1) or anti-(Thy-1.1) antibodies reduced interferon production by 80% and 50% respectively. This finding indicates that (a) the IFN-gamma is produced by Thy-1-positive cells and (b) the production of IFN-gamma by these cells is at least partially under the control of asialo-GM1-positive cells. We also showed that non-adherent fractionated spleen cells from lymphoma-grafted mice produced IL-1 and IL-2. IL-1 was released by asialo-GM1-positive cells and IL-2 by Thy-1-positive cells. Adherent cells released only IL-1. In contrast, total cells released smaller amounts of IL-1 and IL-2, suggesting a reciprocal inhibition between subpopulations of non-adherent and adherent cells. A high level of TNF production by adherent cells was observed only 4 days after the graft. These results indicate that graft of lymphoma cells entails important modifications of spleen cell populations releasing different types of cytokines implicated in NK activation.

Topics: Animals; Antibodies; Antigens, Surface; Biological Factors; Cell Adhesion; Cell Separation; Cell-Free System; Cytokines; Cytotoxicity, Immunologic; Female; G(M1) Ganglioside; Glycosphingolipids; Interferons; Interleukin-1; Interleukin-2; Killer Cells, Natural; Lipopolysaccharides; Lymphocyte Activation; Lymphocytes; Lymphoma; Male; Mice; Mice, Inbred AKR; Mice, Inbred C3H; Neoplasm Transplantation; Spleen; Thy-1 Antigens; Tumor Necrosis Factor-alpha

The highly malignant and metastatic RAW117-H10 cell line was developed by in vivo selection from the Abelson leukemia virus induced parental RAW117-P lymphoma. In this study we have characterized these cell lines with regard to their expression of lymphocyte and macrophage differentiation antigens, adherence, phagocytic properties, binding of various lectins, binding of antibodies to glycolipid asialo-monoganglioside, and the role of butanol extractable cell surface molecules to determine if any of these cell surface properties are associated with the malignant potential of RAW117-H10 cells. The only major difference in immunological phenotypes between RAW117-P and RAW117-H10 cells was an increased expression of Thy-1 molecules by the latter. However, the highly malignant RAW117-H10 cells bound significantly less concanavalin A, Ricinia communis agglutinin, succinylated wheat germ agglutinin, and particularly anti-asialomonoganglioside than their parental counterpart and were resistant to natural killer cell mediated cytolysis. Removal of butanol extractable cell surface molecules significantly decreased the malignancy of RAW117-H10 cells and increased their susceptibility to natural killer cell mediated cytolysis. The butanol treated RAW117-H10 cells regained high in vivo malignancy when recultured for 3 days to permit regeneration of their cell surface components. The butanol extracted RAW117-H10 cells still expressed high levels of Thy-1 indicating that this most probably represented "inappropriate" antigen expression. Since the expression of lymphocyte differentiation antigens did not correlate with the malignant behavior of the cells, we postulate that these antigenic differences merely represent phenotypic variation. The decreased malignant potential of the butanol treated RAW117-H10 cells did correlate with increased cell surface anti-asialomonoganglioside binding (glycolipid) and increased natural killer cell susceptibility.

Topics: Animals; Antigens, Neoplasm; Antigens, Surface; Butanols; Cell Line; Cytotoxicity, Immunologic; G(M1) Ganglioside; Glycosphingolipids; Killer Cells, Natural; Lymphocytes; Lymphoma; Mice; Neoplasm Metastasis; Phagocytosis; Receptors, Antigen, B-Cell; Receptors, Mitogen; Rosette Formation; Surface Properties

The effect of anticoagulant drugs on formation of experimental tumor metastases after i.v. inoculation of BL6 melanoma or Lewis lung carcinoma (3LL) cells was studied in mice with stimulated or depressed natural killer (NK) cell activity. When mice were treated with anticoagulants (warfarin or heparin) or when NK cell activity was stimulated by polyinosinic-polycytidylic acid, significant antimetastatic effects were observed; these effects were substantially augmented when the treatments were combined. However, when NK reactivity of mice was suppressed by anti-asialo GM1 serum or cyclophosphamide, the antimetastatic effects of warfarin and heparin were diminished or completely abrogated. In some experiments, the anticoagulants had a partial effect in mice treated with cyclophosphamide or anti-asialo GM1 serum and reduced at least to control levels the number of metastases in these mice. This limited antimetastatic effect of the anticoagulants was mostly due to the action of residual NK cells, since it was completely abrogated in mice whose NK cell activity was more completely suppressed by two injections of anti-asialo GM1 serum. In addition, the low NK reactivity of 3-week-old C57BL/6 or beige mice was sufficient to support the antimetastatic effects of the anticoagulants, effects that completely disappeared after these mice were treated with anti-asialo GM1 serum. Augmentation or abrogation of the antimetastatic effects of heparin after polyinosinic-polycytidylic acid or anti-asialo GM1 treatments, respectively, was observed in athymic nude and allogeneic BALB/c mice that received i.v. injections of B16F1 melanoma cells, indicating that the antimetastatic effects of anticoagulants depend on the presence of active NK rather than T-cells. Furthermore, adoptive transfer of NK-competent but not NK-depleted syngeneic spleen cells restored the antimetastatic effect of heparin in cyclophosphamide-treated mice. Warfarin treatment increased the elimination of radiolabeled BL6 melanoma cells from the lungs of normal mice, and the rate of tumor cell elimination was further potentiated when NK cell activity was stimulated by polyinosinic-polycytidylic acid. In contrast, after anti-asialo GM1 treatment, warfarin had no effect on the survival of i.v. administered tumor cells. Covering of YAC-1 or 3LL tumor cells with fibrin after in vitro exposure with fibrinogen and thrombin substantially protected them from the in vitro cytotoxic action of NK or lymphokine-activate

Topics: Adjuvants, Immunologic; Animals; Antineoplastic Agents; Combined Modality Therapy; G(M1) Ganglioside; Glycosphingolipids; Heparin; Immune Sera; Immunotherapy; Killer Cells, Natural; Lung Neoplasms; Lymphoma; Melanoma, Experimental; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Nude; Warfarin

An effort has been made to determine the mechanism by which the immunomodulator 3,6-bis(2-piperidinoethoxy)acridine trihydrochloride (CL 246,738) enhances the cytotoxic activity of natural killer (NK) cells. Orally administered CL 246,738 produced augmentation of NK cell activity in mice in a dose-related fashion over a dose range of 10 to 160 mg/kg, with a peak stimulation occurring at 40 mg/kg. The stimulatory effect was short-lived and only persisted for 3 days after a single oral dose of the drug. However, it could be boosted by a subsequent treatment. With anti-asialo GM-1 (anti-ASGM-1) antibody used as an NK cell marker, it was determined that the compound increased the number of ASGM-1-positive cells in mice, as indicated by radioimmunoassay and immunofluorescence staining. NK cells of beige mice were also activated by CL 246,738. Furthermore, the compound at concentrations of 0.02 to 0.2 microgram/ml induced NK cell activity in vitro, with a minimum 3-day incubation being required for optimal activation. This effect was dependent on the presence of macrophages and was inhibited by anti-IFN-alpha + beta but not anti-IFN-beta antibody. Taken together, it is postulated that the compound functions by stimulating macrophages to release IFN-alpha, which subsequently activates NK cells. As an effective stimulator of IFN and NK cells, CL 246,738 may prove clinically useful in the immunotherapy of certain types of malignancy.

Topics: Acridines; Animals; Antibodies; Antigen-Antibody Complex; Cell Line; Cytotoxicity, Immunologic; G(M1) Ganglioside; Glycosphingolipids; Immunosuppressive Agents; Killer Cells, Natural; Lymphocyte Activation; Lymphoma; Mice; Mice, Inbred C57BL

Natural killer (NK) activity of mouse splenocytes was significantly augmented when the splenocytes were incubated for 3 to 4 hr with culture supernatants of mouse thymocytes stimulated by OK-432, an antitumor preparation from the Streptococcus pyogenes SU-strain. Antiviral activity was also detected in the culture supernatants, but IL 2 activity was not. When the culture supernatants of thymocytes stimulated by OK-432 were fractionated on a column of Blue Sepharose CL-6B, NK enhancing activity and antiviral activity were observed in partly overlapping fractions that bound to the column. However, the antiviral activity in the Blue Sepharose-bound fraction was neutralized completely by treatment with anti-IFN (alpha, beta) antiserum, whereas significant NK cell enhancing activity was still observed after treatment with anti-IFN (alpha, beta) antiserum. When the Blue Sepharose-bound fraction was subjected to gel filtration, the NK cell enhancing activity was detected in the 25,000 to 35,000 and 40,000 to 67,000 m.w. regions, but antiviral activity was observed in the over 67,000 m.w. region. These results indicate that a new kind of lymphokine, called natural killer cell activating factor (NKAF), distinct from IFN and IL 2, was found. The NKAF was found to have the following properties: its pI value is between pH 5.5 and 6.5, it binds to concanavalin A- and lentil agglutinin-Sepharose, and it is stable with pH 2-24 hr treatment. In addition, NKAF-producing cells were peanut agglutinin (PNA)-thymocytes when thymocytes were fractionated by the agglutination-sedimentation method with the use of PNA.

Topics: Animals; Biological Products; Cell Line; Culture Media; Cytotoxicity, Immunologic; Dose-Response Relationship, Immunologic; Female; G(M1) Ganglioside; Glycosphingolipids; Growth Inhibitors; Immune Sera; Interferons; Isoelectric Focusing; Killer Cells, Natural; Killer Factors, Yeast; Kinetics; Lectins; Lymphocyte Activation; Lymphoma; Mast-Cell Sarcoma; Mercaptoethanol; Mice; Mice, Inbred C3H; Molecular Weight; Peanut Agglutinin; Picibanil; Protein Biosynthesis; Proteins; T-Lymphocytes

Spleen cells from mouse bone marrow chimaeras were cultured in vitro in mixed lymphocyte cultures (MLC) or in the presence of interleukin 2 (IL-2) without the added alloantigen. Precursors for the nonspecific cytotoxic cells (in this study: lymphokine-activated killer (LAK) cells) lysing natural killer (NK) cell-sensitive YAC-1 lymphoma could be found 10-12 days after the bone marrow reconstitution, simultaneously with the appearance of the NK activity. The ability of LAK cells to lyse NK-resistant tumour targets as well was demonstrated using the P 815 mastocytoma cell line; reactivity against this target was demonstrable 1 week later than the appearance on YAC-1 lysing cells. Phenotypically LAK cells derived from spleen cell cultures of bone marrow chimaeras did not differ from LAK cells derived from normal spleen cell cultures: precursors resided within the Thy 1-, asialo-GM1+ cell population, and effectors expressed both of these antigens. Splenic NK cells of early bone marrow chimaeras (up to 14-18 days after the bone marrow reconstitution) were Thy 1+ cells, and thus LAK cells of bone marrow chimaeras were not derived from these Thy 1+ NK cells. The treatment of effector cells with anti-Thy 1 antibody plus complement (C) abolished the lytic activity totally. However, these cells were not cytotoxic T cells, since alloreactivity, as an indication of the T-cell cytotoxicity, could not be demonstrated until 4-5 weeks after the bone marrow reconstitution.

Topics: Animals; Antigens, Surface; Bone Marrow Cells; Cell Differentiation; Cells, Cultured; Cytotoxicity, Immunologic; G(M1) Ganglioside; Glycosphingolipids; Immunity, Cellular; Interleukin-2; Killer Cells, Natural; Lymphokines; Lymphoma; Mice; Radiation Chimera; T-Lymphocytes, Cytotoxic; Thy-1 Antigens

Natural cytotoxic activity by Thy-1 negative, asialo-GM-1 positive and column-nonadherent spleen cells was detected against YAC-1 target cells but not against Meth-A and EL-4 target cells as reported by many investigators. In the present study, on the other hand, natural cytostatic activity was detected in Thy-1 negative, asialo-GM-1 negative and column-nonadherent cells and this activity was effective against YAC-1, Meth-A and EL-4 target cells. Such a cytostatic activity was not modified by the functional levels of T cells in the donor mice of effector cells. The cytostatic activity against Meth-A and EL-4 target cells was detected not only in an allogeneic system but also in a syngeneic system. The cytostatic activity was not depressed in a tumor-bearing state in contrast to the NK activity. The cytostatic activity as well as the NK activity was detected in spleen and peritoneal cells but not in lymph node cells of the various sources. The spleen and peritoneal cavity may play a role distinct from that of lymph nodes in the resistance against tumor development.

Topics: Animals; Cytotoxicity, Immunologic; G(M1) Ganglioside; Glycosphingolipids; Immunity, Innate; In Vitro Techniques; Killer Cells, Natural; Lymphoma; Male; Mice; Mice, Inbred Strains; Mice, Nude; Neoplasms, Experimental; T-Lymphocytes, Cytotoxic

Spleen cells from C.B- 17 scid mice with severe combined immunodeficiency disease exhibit natural killer cell (NK) activity against YAC lymphoma targets in a standard 4-hr 51Cr release assay. The cytolytic activity is demonstrable only at high effector to target ratios but can be augmented at least sevenfold by the interferon inducer poly I:C. The pattern of target lysis is specific, because splenocytes from poly I:C-primed C.B-17 scid mice lyse NK-sensitive YAC cells and not the insensitive P815 mastocytoma. The presence of several NK-associated antigens on C.B-17 scid splenocytes was tested by pretreating cells with the appropriate antiserum plus complement before testing for NK activity. The results indicate that a proportion of NK effectors in C.B-17 scid mice bear surface NK 2.1 and Asialo GM1 but are negative for Thy-1.

Topics: Animals; Antibodies, Monoclonal; Cytotoxicity, Immunologic; G(M1) Ganglioside; Glycosphingolipids; Immunologic Deficiency Syndromes; Isoantibodies; Killer Cells, Natural; Lymphoma; Mice; Mice, Mutant Strains; Phenotype; Spleen

Mice treated with anti-asialo GM1 (asGM1) serum exhibited increased formation of experimental metastases in lung and liver after i.v. challenge with B16 melanoma or Lewis lung carcinoma. This increased metastasis formation coincided with decreased splenic NK activity and increased survival of i.v. injected radiolabeled tumor cells. In contrast, the injection of mice with the pyran copolymer maleic anhydride divinyl ether (MVE-2) augmented NK activity in the spleen and significantly depressed the formation of experimental metastases in the lungs and liver. However, a single or double administration of anti-asGM1 antiserum to MVE-2-pretreated mice failed to inhibit the immunoprophylaxis associated with MVE-2 administration, although it did decrease splenic NK activity and also increased the survival of i.v.-injected radiolabeled tumor cells. To address the mechanism for this dichotomy, we examined NK activity not only in the spleen but also in the blood, lungs, and livers of MVE-2-treated mice. Levels of NK activity in the lungs and liver were several-fold higher than those observed in spleen and blood. However, MVE-2-augmented NK activity in lung and liver was more resistant to depletion by the standard regimen of anti-asGM1 treatment than was NK activity in blood and spleen, and required two high-dose administrations of a higher titered antiserum for depletion of the augmented response. This high-dose regimen removed all detectable NK activity from the lung and liver, and concomitantly eliminated the metastasis-inhibiting effect of MVE-2. These data are consistent with a role for organ-associated NK cells in inhibiting metastasis formation during the extravasation and/or early postextravasation phases of the metastatic process. The results also suggest that biologic effects of NK activity in spleen and blood can be dissociated from those mediated by NK activity in other organs by use of different treatment regimens with anti-asGM1 serum. Finally, because NK activity in target organs can be augmented to an even greater extent than in the blood and spleen by at least some biologic response modifiers (BRMs), organ-associated NK activity should be considered as a possible mechanism for the therapeutic effects of BRM treatment.

Topics: Animals; Antineoplastic Agents; Cytotoxicity, Immunologic; Female; G(M1) Ganglioside; Glycosphingolipids; Growth Substances; Immune Sera; Killer Cells, Natural; Liver Neoplasms; Lung Neoplasms; Lymphoma; Male; Melanoma; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Organ Specificity; Pyran Copolymer

Natural killer (NK) activity in the rat and human has been attributed to cells having the morphology of large granular lymphocytes (LGL). However, this association has been less clear in the mouse, largely because of difficulties in obtaining highly enriched populations of LGL from normal spleen and blood. We have previously observed that the administration of the biological response modifier (BRM) maleic anhydride divinyl ether (MVE-2) strongly augmented NK activity in lung and liver, and the augmented NK activity coincided with increased resistance to the formation of experimental metastases in these organs. The degree of NK augmentation was most striking in the liver, an unexpected and previously unreported observation. In the present study, both MVE-2 or Corynebacterium parvum induced a dramatic augmentation of liver NK activity, which reached maximum levels 3-5 d after treatment. This augmentation of NK activity in the liver coincided with a large increase in the number of lymphoid cells with the morphological characteristics of LGL that could be isolated from enzymatically digested suspensions of perfused liver. The yield of LGL per liver following BRM treatment corresponded to a 10-50-fold increase as compared to normal mice. LGL were purified from these enzymatically digested suspensions of perfused liver by depletion of adherent cells on nylon wool columns and subsequent enrichment for low-density lymphoid cells by fractionation on Percoll density gradients. The enrichment of LGL correlated with greatly increased NK activity against YAC-1. Conversely, the higher-density fractions were depleted of both LGL and NK activity. This increase in NK activity in the liver was suppressed by in vivo treatment with anti-asialo GM1 (asGM1) serum. This treatment also resulted in a corresponding reduction in both the total number and percentage of LGL. By flow cytometry analysis, the phenotype of the majority of these highly cytolytic LGL isolated from the livers of BRM-treated mice were asGM1+, Thy-1+, Ly-5+, Qa-5+, Mac-1+, and Gma-1+, whereas these LGL were Ly-1-, Lyt-2-, L3T4-, and surface Ig-. We conclude that the livers of BRM-treated mice can provide a rich source of highly active mouse LGL that could be used for further characterization of this lymphocyte subset. Further, these studies imply a potential for BRM therapy of neoplastic or viral diseases through augmentation of organ-associated immune responses.

Topics: Adjuvants, Immunologic; Animals; Antigens, Surface; Ascitic Fluid; Cell Line; Cell Separation; Cytotoxicity, Immunologic; Female; G(M1) Ganglioside; Glycosphingolipids; Immune Sera; Killer Cells, Natural; Leukemia L5178; Liver; Lymphoma; Male; Mice; Mice, Inbred C57BL; Organ Specificity; Phenotype; Polymers; Propionibacterium acnes; Pyran Copolymer; Spleen

The usefulness of asialo GM1, a glycolipid surface marker, to define the effector cell types involved in tumor resistance in vitro and in vivo was assessed. Pretreatment of rat effector cells with anti-asialo GM1 antibody plus complement in vitro either abrogated or markedly diminished NK activity; in contrast, macrophage-type cytocidal activity was not diminished by such pretreatment. Similarly, systemic inoculation of anti-asialo GM1 antibody selectively eliminated NK activity, leaving macrophage-type tumoricidal reactivity intact. Finally, such pretreatment did not diminish host resistance in an in vivo tumor model in which the available evidence suggests a critical role for macrophages. The asialo GM1 marker may thus be useful in delimitating the tumoricidal capacity of cells exhibiting NK activity from that mediated by other cell types.

Topics: Animals; Antibodies; Cytotoxicity, Immunologic; Fibrosarcoma; G(M1) Ganglioside; Glycosphingolipids; Killer Cells, Natural; Lymphoma; Macrophages; Mice; Neoplasms, Experimental; Rats

Killer cells with natural killer (NK) cell-like target selectivity were generated when C3H or C57BL/6 mouse spleen cells were cultured in vitro. Compared with NK cells, the in vitro-generated killer cells with NK-like reactivity were slightly adherent to nylon wool fibers, a little more sensitive to anti-Thyl.2 antibody plus complement and almost entirely resistant to cytotoxic treatment with anti-asialo GM1 antiserum which is selectively cytotoxic to NK cells. The culture of NK-depleted spleen cells yielded a lower degree of NK-like cytotoxicity, thus it seems likely that NK cells changed to NK-like killer cells in vitro. Competitive inhibition studies suggested that the in vitro-generated NK-like cells were different from alloantigen-reactive killer T cells. The above results, therefore, might suggest that in vitro-induced NK-like cells do not belong to any known subset of killer cells.

Topics: Animals; Cell Adhesion; Cells, Cultured; Cytotoxicity, Immunologic; G(M1) Ganglioside; Glycosphingolipids; Immune Sera; Killer Cells, Natural; Lymphocyte Culture Test, Mixed; Lymphoma; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Phagocytes; Spleen; Time Factors

Topics: Animals; Antibodies; G(M1) Ganglioside; Glycosphingolipids; Killer Cells, Natural; Kinetics; Lymphoma; Mice; Mice, Nude; Neoplasms, Experimental

The BCG-induced NK cell activity of murine peritoneal exudate cells was abolished by preincubation of effector cells with anti-ganglio-N-tetraosylceramide (anti-asialo GM1) and C but not with other anti-glycolipid antibodies, anti-ganglioside GM1, anti-globoside, and anti-ganglio-N-triosylceramide (anti-asialo GM2). In contrast, the cytotoxic activity of alloimmune T cells was not affected by treatment with anti-asialo GM1 antisera. These findings suggest that asialo GM1 display may be characteristic of NK cell populations and aid in the isolation of this population of cytotoxic cells.

Topics: Animals; Cell Membrane; Complement System Proteins; Cross Reactions; G(M1) Ganglioside; Globosides; Glycosphingolipids; Immune Sera; Killer Cells, Natural; Lymphoma; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Mycobacterium bovis; Neoplasms, Experimental; Rabbits; T-Lymphocytes