Transfer Of Immune Spleen Cells Research Articles

The chemokine receptor CCR5, a therapeutic target for HIV/AIDS antagonists, is critical for recovery in a mouse model of Japanese encephalitis.

Japanese encephalitis is a severe central nervous system (CNS) inflammatory disease caused by the mosquito-borne flavivirus, Japanese encephalitis virus (JEV). In the current study we have investigated the immune responses against JEV in mice lacking expression of the chemokine receptor CCR5, which functions in activation and chemotaxis of leukocytes during infection. We show that CCR5 serves as a host antiviral factor against Japanese encephalitis, with CCR5 deficiency markedly increasing mortality, and viral burden in the CNS. Humoral immune responses, which are essential in recovery from JEV infection, were of similar magnitude in CCR5 sufficient and deficient mice. However, absence of CCR5 resulted in a multifaceted deficiency of cellular immune responses characterized by reduced natural killer and CD8+ T cell activity, low splenic cellularity, and impaired trafficking of leukocytes to the brain. Interestingly, adoptive transfer of immune spleen cells, depleted of B lymphocytes, increased resistance of CCR5-deficient recipient mice against JEV regardless of whether the cells were obtained from CCR5-deficient or wild-type donor mice, and only when transferred at one but not at three days post-challenge. This result is consistent with a mechanism by which CCR5 expression enhances lymphocyte activation and thereby promotes host survival in Japanese encephalitis.

Importance of IFN-γ-Mediated Expression of Endothelial VCAM-1 on Recruitment of CD8+T Cells into the Brain During Chronic Infection withToxoplasma gondii

Interferon-gamma (IFNgamma) is essential for preventing reactivation of chronic infection with Toxoplasma gondii in the brain. We examined the role of IFNgamma on lymphocyte and endothelial adhesion molecule expression and T cell recruitment into the brain during chronic infection with T. gondii in IFNgamma knockout (IFNgamma(-/-)) and wild-type (WT) mice. Although the number of cerebral vessels expressing intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) increased in both WT and IFNgamma(-/-) mice following infection, there were more VCAM-1(+) vessels in brains of infected WT than of infected IFNgamma(-/-) mice; in contrast, numbers of ICAM-1(+) vessels did not differ between strains. We did not detect endothelial E-selectin, P-selectin, MAdCAM-1, or PNAd in any of the brains. Significantly fewer CD8(+) T cells were recruited into brains of infected IFNgamma(-/-) than WT mice. Treatment of infected IFNgamma(-/-) mice with recombinant IFN-gamma restored the expression of VCAM-1 on their cerebral vessels and recruitment of CD8(+) T cells into their brains, confirming an importance of this cytokine for upregulation of VCAM-1 expression and CD8(+) T cell trafficking. In infected WT and IFNgamma(-/-) animals, almost all cerebral CD8(+) T cells were lymphocyte function-associated antigen-1 (LFA-1)(high), CD44(high), and CD62L(neg), and approximately 38% were alpha4beta1 integrin(+). In adoptive transfer of immune spleen cells, pretreatment of the cells with a monoclonal antibody (mAb) against alpha4 integrin markedly inhibited recruitment of CD8(+) T cells into the brain of chronically infected WT mice. These results indicate that IFN-gamma-induced expression of endothelial VCAM-1 and its binding to alpha4beta1 integrin on CD8(+) T cells is important for recruitment of the T cells into the brain during the chronic stage of T. gondii infection, although LFA-1/ICAM-1 interaction may also be involved in this process.

Requirement of non-T cells that produce gamma interferon for prevention of reactivation of Toxoplasma gondii infection in the brain.

We examined the mechanism of resistance against reactivation of infection with Toxoplasma gondii in the brain. BALB/c-background gamma interferon (IFN-gamma)-knockout (IFN-gamma(-/-)) and control mice were infected and treated with sulfadiazine beginning 4 days after infection for 3 weeks. After discontinuation of treatment, IFN-gamma(-/-) mice succumbed to toxoplasmic encephalitis (TE) and died, whereas control animals did not develop TE and survived. Adoptive transfer of immune spleen cells from infected control mice did not prevent development of TE or mortality in the IFN-gamma(-/-) mice. To examine whether the failure of the cell transfer to protect against TE is unique to IFN-gamma(-/-) mice, athymic nude and SCID mice that lack T cells were infected and injected with the immune spleen or T cells in the same manner as IFN-gamma(-/-) mice. Whereas control nude and SCID mice that had not received the immune cells developed severe TE and died after discontinuation of sulfadiazine, those that had received the cells did not develop TE and survived. Before cell transfer, IFN-gamma mRNA was detected in brains of infected nude and SCID but not in brains of IFN-gamma(-/-) mice. IFN-gamma mRNA was also detected in brains of infected SCID mice depleted of NK cells by treatment with anti-asialo GM1 antibody, and such animals did not develop TE after receiving immune T cells. Thus, IFN-gamma production by non-T cells, in addition to T cells, is required for prevention of reactivation of T. gondii infection in the brain. The IFN-gamma-producing non-T cells do not appear to be NK cells.

Role of cytokines in GVL (ESb lymphoma) and GVHD after adoptive transfer of allogeneic T lymphocytes in mice.

ESb lymphoma cells injected i.v. into DBA/2 (H-2d) mice multiply rapidly in the liver and kill all mice in a few days. Adoptive transfer of allogeneic C57B1/6 (H-2b) tumor-immune or normal splenic lymphocytes to sublethally irradiated DBA/2 mice induced a marked antitumor state, graft-versus-leukemia (GVL), increasing the mean survival time 2-3-fold, but also induced an acute and lethal graft-versus host disease (GVHD). We have undertaken experiments to try to dissociate GVL from GVHD. Transfer of immune spleen cells induced a greater GVL than transfer of normal spleen cells with an equivalent to GVHD. Three to five million immune or normal CD8+ T lymphocytes were sufficient to induce both GVL and GVHD. Individual DBA/2 mice were labeled and followed. In mice undergoing GVHD, the spleens were repopulated by donor (H-2b) lymphocytes, and tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were present in the sera of 26 of 27 and 18 of 20 mice, respectively, together with increased amounts of TNF-alpha and IL-6 mRNA in their spleens. This was in contrast to DBA/2 mice receiving allogeneic cells but not developing GVHD. Both interferon-alpha/beta (IFN-alpha/beta) and IL-12, which had proven very effective in association with adoptive transfer of syngeneic immune T lymphocytes in inhibiting ESb metastases, enhanced GVHD when administered with allogeneic immune or normal spleen cells, and >90% of mice died. Intensive IL-2 treatment inhibited GVHD while maintaining GVL.

The spleen, IgG antibody subsets and immunity to Plasmodium berghei in rats.

The development of IgG subclass-specific antibody responses to Plasmodium berghei in spleen-chimeric rats were monitored to determine if there was any relationship between IgG subset profiles and resistance. Strongly immune eusplenic rats respond to challenge with P. berghei by producing high levels of parasite-specific IgG2a, IgG2b and IgG2c but only modest levels of IgG1. Splenectomy profoundly affects the antibody response to infection. Thus, in splenectomized immunized rats, which harbour a chronic parasitaemia of 1%, the IgG2a, IgG2b and IgG2c responses peak 1 week later than in eusplenic immunized rats although the size of the peak is similar. More marked effects are apparent in the IgG1 response, the magnitude of which is far greater in splenectomized immunized rats than eusplenic immunized rats. Similar antibody profiles are seen in splenectomized immunized rats transplanted with a naive spleen. In contrast, splenectomized naive rats receiving either a transplant of a spleen from an immune rat or a transfer of immune spleen cells have high levels of IgG2a, IgG2b and IgG2c but modest levels of IgG1. However, only the former group of rats completely clears the parasite, the latter maintaining a chronic 1% parasitaemia. Thus, although complete resistance to P. berghei is always associated with high levels of parasite-specific IgG2a, IgG2b and IgG2c plus modest levels of IgG1, this is not a sufficient set of conditions to guarantee complete immunity. The IgG subset profile may be related to cytokine production; IFN-gamma was detected in the sera of rats receiving spleens from rats immune to P. berghei (modest IgG1 responses) but not in rats receiving spleens from naive animals (pronounced IgG1 responses).

Characterization of a murine lymphoma cell line by 31P-NMR spectroscopy: in vivo monitoring of the local anti-tumor effects of systemic immune cell transfer.

The intradermal ESb-MP murine T-cell lymphoma in syngeneic DBA/2 mice has been used as a model for adoptive immunotherapy (ADI). Cultured ESb-MP cells were characterized in suspension by 31P-NMR spectroscopy (MRS) at 11.7 T, and solid primary tumors were examined by 31P-MRS in vivo at 7.0 Tesla using surface-coil techniques. Growing tumors contained relatively high levels of phosphomonoesters (PME, predominantly phosphoethanolamine), nucleotides (NTP) and Pi, low levels of phosphodiesters (PDE) and no phosphocreatine. Mean tissue pH was found to be 6.7-6.9. The spectra of ESb-MP cells cultured in RPMI medium (containing choline but no ethanolamine) also showed low PDE and no phosphocreatine at an intracellular pH of 7.4; however, only a trace amount of phosphoethanolamine was detected and significant levels of nucleoside mono- and diphosphates were observed. The complete ADI treatment protocol involved low-dose irradiation (5 Gy) followed by i.v. transfer of immune spleen cells from allogeneic B10.D2 donors and resulted in 100% remission (responders); no treatment or incomplete ADI (irradiation or immune cell transfer alone) resulted in no remissions (nonresponders). In vivo MRS could best discriminate between responders and non-responders on the basis of tissue pH, which increased in responders to 7.0 by day 5-6 after complete ADI. Following therapy, the sum of PME + Pi (both absolute and as a percent of total phosphates) decreased significantly only for responders but only after a visible decrease in tumor volume was apparent.

Cytotoxic T cell effector and memory function in viral immunity.

The first evidence that virus-specific CD8+ cytotoxic T lymphocytes (CTLs) are primary effectors in vivo came shortly after the discovery of major histo- compatibility complex (MHC)-restricted CD8+ CTL activity (Zinkernagel and Doherty 1974). Adoptive transfer of immune spleen cells from mice of MHC type A into A or (AxB) F1, but not B, virus-infected recipients caused massive inflammatory pathology (Doherty and Zinkernagel 1975; DOHERTY et al. 1976b) and acute elimination of the pathogen (BLANDEN et al. 1975a; Zinkernagel and Welsh 1976). This was repeated for situations in which A and B represented different MHC haplotypes or distinct allelic forms of class I MHC glycoproteins (Doherty and Zinkernagel 1975; Blanden et al. 1975b; Doherty et al. 1976a). The analysis was extended to H-2 mutant mice and, again, the spectrum of cross-reactivity for T cell effector function in vivo and CTL activity in vitro seemed to run in parallel (Doherty et al. 1976a; Zinkernagel and Doherty 1979).

Effects of adoptive transfer of immune spleen cells on worm growth and microfilaraemia inBrugia pahangiinfection in Mongolian gerbils

Protective immunity against Brugia pahangi was examined after adoptive transfer of immune spleen cells. Spleen cells obtained from gerbils at 8 weeks post-infection (p.i.) with 100 infective larvae (L3) of B. pahangi were transferred into naive recipients, and then 24 h later, they were infected with 100 L3 of B. pahangi. The recipients given normal spleen cells and infected by the same manner served as controls. Microfilarial counts in the circulation were monitored at designated times after infection and worm burden and the size of individual female worm were determined at 16 weeks p.i. to evaluate the effects of adoptive immunization. In addition, eosinophil responses and serum antibody titres were examined during the course of infection. In the control group, microfilariae first appeared in circulation at 9 weeks p.i. and continuously increased in number throughout the course examined. In contrast, microfilaraemia was almost completely suppressed in the group given immune spleen cells. Although worm burden was comparable between the two groups, the average size of female adult worms recovered from the adoptively immunized group was significantly smaller than that from the control group. Eosinophil response was hastened and enhanced by adoptive transfer of immune spleen cells in the early stage of infection. Parasite-specific antibody response was also hastened by adoptive immunization. These results suggest that immune spleen cells could confer protective immunity mainly directed against adult B. pahangi.

CD8+ T cell‐mediated protection against an intracellular bacterium by perforin‐dependent cytotoxicity

Growth of Listeria monocytogenes is mainly controlled by macrophages, which are activated by specific T cells. A potential role of CD8+ T cells by direct lysis of infected cells was investigated in perforin-deficient mice generated by homologous recombination. The absence of perforin-mediated cytotoxicity resulted in delayed clearance of Listeria from the spleen but not the liver after primary infection, overall susceptibility to Listeria however was not increased. Protection against a secondary infection was drastically impaired in perforin-deficient mice. Adoptive transfer of immune spleen cells to recipients revealed that anti-Listeria protection by CD8+ T cells from perforin-deficient versus normal mice was about 10-fold reduced in livers and about 100-fold reduced in the spleen of recipients. CD4+ T cells from immune control and perforin-deficient mice conferred comparable protection. These results indicate that the protective effect of CD8+ T cells against an intracellular bacterium mainly evident in secondary infection is mediated by a perforin-dependent pathway, presumably cytotoxicity, and less by other direct or indirect effector mechanisms.

GAMMA-IRRADIATION SUPPRESSES T-CELL MEDIATED PROTECTIVE IMMUNITY AGAINST A METASTATIC TUMOR IN THE AFFERENT PHASE OF THE IMMUNE-RESPONSE BUT ENHANCES IT IN THE EFFERENT PHASE WHEN GIVEN BEFORE IMMUNE CELL TRANSFER

Using a metastasizing animal tumor as a model we describe experimental conditions for obtaining either synergistic or antagonistic effects between host irradiation and T cell mediated antitumor immunity. The results were obtained in the well defined murine lymphoma ESb which is a spontaneous highly metastatic tumor variant expressing a tumor associated antigen that can induce protective immunity and tumor specific cytotoxic T lymphocyte (CTL) activity. Sublethal irradiation of mice during the afferent (induction) phase but not during the efferent (effector) phase of the antitumor immune response had a strong suppressive effect on protective immunity. The radiation mediated defect could be reconstituted by transfer of immune spleen cells. The immune system of syngeneic (DBA/2) and allogeneic (B10.D2) mice changed within 24 h after first contact with the ESb tumor cells from radio-sensitivity to radio-resistance possibly reflecting an active cellular response associated with the change from virgin to an antigen sensitized (primed) state of T lymphocyte differentiation. T cell depletion experiments revealed that the afferent phase was dependent on both CD4 and CD8 host T lymphocytes while the efferent phase was mainly CD8 T cell dependent. A synergistic effect between gamma-irradiation and antitumor immunity was observed in adoptive immunotherapy experiments. When tumor-bearing hosts were irradiated before intravenous transfer of either syngeneic or allogeneic antitumor immune T cells the expression of anti-metastatic protective immunity was greatly enhanced in comparison to identically treated non-irradiated hosts.

Cell-mediated immunity to Bordetella pertussis: role of Th1 cells in bacterial clearance in a murine respiratory infection model.

A murine respiratory infection model was used to study the mechanism of protective immunity to Bordetella pertussis. We found that nude mice, which are deficient in T cells, developed a persistent infection and failed to clear the bacteria after aerosol inoculation. In contrast, normal adult nonimmune mice cleared a respiratory infection approximately 35 days after challenge. Before bacterial clearance, antipertussis antibody levels in serum were low or undetectable, whereas consistent antigen-specific T-cell responses were demonstrated throughout the course of infection. The in vitro responses detected in immune spleen cells were mediated by a population of CD4+ major histocompatibility complex class II-restricted Th1-like cells that secreted interleukin-2 and gamma interferon but not interleukin-4. Adoptive transfer of immune spleen cells into nude or sublethally irradiated immunosuppressed mice before challenge resulted in bacterial clearance within 14 to 21 days. In contrast, injection of serum from convalescent mice before challenge only marginally reduced the bacterial load early in the course of infection. Furthermore, transfer of enriched T cells or purified CD4+ T cells but not CD8+ T cells from immune mice conferred a high level of protection. Recipients of CD4+ T cells cleared the bacteria from the lungs within 20 days of challenge, at which time B. pertussis-specific antibodies in the serum were undetectable. Although we do not rule out a contribution of mucosal immunoglobulin A, our findings suggest that cellular responses mediated by CD4+ Th1 cells play an important role in protective immunity to B. pertussis.

Cell-mediated antiviral response to equine herpesvirus type 1 demonstrated in a murine infection model by means of adoptive transfer of immune cells.

Protection against equine herpesvirus type 1 (EHV-1) infection in a mouse model has been studied by means of delayed-type hypersensitivity (DTH) and adoptive transfer of immune spleen cells. Mice were found to develop a positive DTH response to EHV-1 antigen which was sustained for several months after primary inoculation. The response was found to cross-react with EHV-4-derived antigen. Immune cells (from mice primed with live or heat-inactivated EHV-1) conferred an enhanced DTH response on recipients; however, only the immune cells that were previously primed with live EHV-1 gave protection against re-infection. The degree of protection was also dependent on the number of spleen cells transferred. Immune cells from mice primed with heat-inactivated EHV-1 appeared to enhance virus replication following subsequent inoculation. The serum antibody response to EHV-1 appeared to be slightly suppressed in recipients of spleen cells from mice primed with either live or heat-inactivated virus. These results support the important role for cell-mediated responses in protective immunity to EHV-1 and provide clues to the nature of protection and immunopathology in the natural host.

Transfer of lymphocytic choriomeningitis disease in beta 2-microglobulin-deficient mice by CD4+ T cells.

In this study we have investigated the role of CD4+, MHC class II-restricted cytotoxic T lymphocytes (CTLs) in the disease caused by lymphocytic choriomeningitis virus (LCMV) in beta 2-microglobulin deficient (beta 2m-) mice. Intracranial (i.c.) infection with LCMV resulted in death of six out of 11 beta 2m- mice. Mice that survived showed a marked loss in body weight. Death and loss of body weight could be prevented by immunosuppressing the mice with irradiation or cyclosporine prior to i.c. injection of LCMV. This treatment also prevented induction of virus-specific, MHC class II-restricted CTL following peripheral inoculation with LCMV. In vivo depletion of CD4+ cells with antibody also prevented death following i.c. injection whereas in vivo depletion of CD8+ cells had no effect. Disease could be transferred to recipient beta 2m- mice by adoptive transfer of beta 2m- derived immune spleen cells. Transfer of non-immune spleen cells did not result in illness. In vitro treatment of immune spleen cells with anti-CD4 antibody and complement eliminated class II-restricted CTL activity and also prevented mortality of recipients after adoptive transfer. Treatment with anti-CD8 antibody had no effect. We were unable to transfer LCM disease to beta 2m- recipients by adoptive transfer of immune spleen cells from C57BL/6 mice. These results suggest that, unlike normal mice, the pathology of LCM disease in beta 2m- mice is dependent upon virus-specific, CD4+CD8-, MHC class II-restricted T cells.

Inability of Plasmodium vinckei-immune spleen cells to transfer protection to recipient mice exposed to vaccine‘vectors’or heterologous species of plasmodium

Mice can be immunized to Plasmodium vinckei by repeated infections followed by cure. Such immunity is dependent on CD4 T cells and an architecturally modified spleen, but has little requirement for antibody. Thus, athymic mice can be exposed to P. vinckei and cured, but do not develop immunity. They are resistant to challenge with parasites, however, if they are then given spleen cells from euthymic immunized animals. Such immune spleen cells, however, cannot transfer resistance to normal mice which have been exposed to BCG, Salmonella typhimurium, or vaccinia virus, and are only partially effective in transferring resistance to mice which have been previously immunized with heterologous plasmodia, P. yoelii, P. chabaudi and P. berghei. Mice exposed to varying numbers of irradiated P. vinckei-pRBC do not develop immunity and nor are such animals protected following adoptive transfer of immune spleen cells. Cellular immunity to malaria may not only be dependent on a population of immune CD4 T cells, but may require a specifically architecturally modified spleen which may not occur following either exposure to candidate vaccine vectors, heterologous plasmodia or non-viable homologous plasmodia.

Acanthocheilonema viteae (Dipetalonema viteae) in mice: Attempts to correct the low responder phenotype of the BALB/c host

Attempts were made to correct the low responder phenotype of microfilaraemic Acanthocheilonema viteae ( Dipetalonema viteae) infected BALB/c mice through the transfer of immune spleen cells and immune serum from amicrofilaraemic B10 background mice. The transfer of immune cells and serum prior to infection failed to influence development of microfllaraemia in BALB/c recipients. Attempts to alter the course of an established microfilaraemia in BALB/c mice through the transfer of 3 × 10 7 immune spleen cells were unsuccessful but transfer of 3 × 10 8 cells reduced microfilaraemia temporarily. Treating microfilaraemic BALB/c mice with immune serum brought about a rapid reduction in microfllaraemia. This effect was only temporary and numbers of circulating microfllariae returned to control levels within a short time. Repeated serum transfers reduced the microfilaraemia only during the period of treatment. Similar results were obtained when immune serum was given to microfilaraemic, immunodeficient CBA/N mice.

Analysis of colony-stimulating factors and macrophage progenitor cells in mice immunized against Listeria monocytogenes by adoptive transfer.

Experiments were performed to elucidate the role of colony-stimulating factors in host defenses to the intracellular pathogen Listeria monocytogenes. Mice were protected against Listeria sp. by adoptive transfer of immune spleen cells and were then challenged with listeriae intravenously. Control mice were injected with spleen cells from uninfected mice. Adoptively immunized (immune) mice had significantly fewer listeriae in spleens and livers 2 and 4 days after Listeria challenge than did control mice. During acute infection, colony-stimulating activity in serum was increased earlier (10 h) in immune mice than in controls. Concentrations of colony-stimulating activity were equal at 24 h. By 48 h, values were decreased in immune mice, but were elevated in control mice. Similar changes were noted when a specific colony-stimulating factor, macrophage colony-stimulating factor, was measured in serum by using a radioimmunoassay. The changes in serum colony-stimulating activity in mice adoptively immunized with immune spleen cells were eliminated if spleen cells were first treated with anti-Thy-1.2 monoclonal antibodies. The number of macrophage progenitor cells in bone marrow and spleen were also determined as measures of the hemopoietic potential in these organs. The number of macrophage progenitor cells in bone marrow was higher in immune animals than control animals at 1, 2, and 4 days of infection. Similarly, the number of these cells in spleens was higher during the early stages of infection in immune mice. These results indicate that both the regulation of leukocyte production and the transfer of specific cellular immunity by spleen cells are associated, and they therefore suggest that hemopoietic regulatory factors play a role in immune host defenses.

Lewis lung carcinoma (3LL) cells treated in vitro with ultraviolet radiation show reduced metastatic ability due to an augmented immunogenicity.

The metastatic ability of 3LL tumor following in vitro irradiation with ultraviolet (u.v.) light was studied. Tumor cells were exposed to two courses of u.v.-irradiation (3LL X 2u.v. cells) and after two weeks of culture they were inoculated intravenously (i.v.) into syngeneic mice. These cells produced significantly fewer pulmonary metastases than the untreated population. In addition, intrafootpad (i.f.p.) injections of 3LL X 2u.v. cells into immunocompetent animals induced tumors only in 40 per cent of recipients. Interestingly, in normal mice with progressively growing 3LL X 2u.v. tumors, the formation of spontaneous pulmonary metastases was prevented, whereas metastatic foci were observed in 70 per cent of the nude recipients. The metastatic properties of u.v.-treated tumor cells were further analysed by using individual clones with varying immunogenicity. We found that variants with augmented immunogenicity also showed a parallel decrease in metastatic potential. Studies on H-2 antigen expression in different clones revealed that immunogenic and low metastatic variants expressed levels of H-2 antigens higher than the tumorigenic and metastatic clones. Finally, by using cyclophosphamide (Cy) treatment and adoptive transfer of immune spleen cells were able to eradicate macroscopic 3LL pulmonary metastasis. These results demonstrate that the decrease of metastatic ability in u.v.-treated cells was mainly due to an increase in their immunogenicity and H-2 antigen expression.

Histological evaluation of immunologically mediated tumor regression of the line 10 guinea pig hepatocarcinoma.

The histology of immunologically mediated tumor regression was studied in the syngenic strain 2 guinea pig/line 10 hepatocellular carcinoma tumor system. Tumor regression was induced non-specifically by the intralesional injection of living Bacillus Calmette-Guérin (BCG) in 7-day-old established tumors (diameter 8-10 mm). In untreated line 10 tumors at day 7 a mild to moderate inflammatory reaction was present, which consisted mainly of small mononuclear cells; in addition large mononuclear cells and basophils were present. Intratumoral BCG-treatment induced a prominent increase in the inflammatory reaction due to an influx of small and large mononuclear cells and neutrophils. Small mononuclear cells were identified mainly as lymphocytes whereas large mononuclear cells belonged mainly to the macrophage line. Intratumoral administration of BCG resulted in a granulomatous reaction. A time-related decrease in the number of tumor cells and an increase in inflammation, associated with purulent lysis of the granulomatous tissue, was observed. Specific immune-mediated tumor rejection occurred in animals both after active immunization and after adoptive transfer of immune spleen cells. In actively immunized animals the tumor cells were rapidly rejected and from day 4 onwards no tumor cells could be detected at the injection site. Lymphocytes were the major component of the inflammatory reaction; large mononuclear cells were present to a lesser extent and basophilic granulocytes were regularly observed. After adoptive transfer of immunity with immune spleen cells given simultaneously with an intradermal innoculation of tumor cells, an essentially similar rejection reaction was found, although tumor cell rejection was delayed. Lymphocytes and large mononuclear cells were found in equal proportions, whereas basophilic granulocytes were always present in smaller numbers. After BCG-induced regression and in adoptively transferred immune rejection, a fibroblast component was more prominent than in untreated control tumors. This reaction tended to isolate smaller tumor cell areas into islets of decreasing sizes. In contrast with the fibroblast component of growing tumors, the proliferative pre-existing fibrous tissue in tumors undergoing regression or rejection showed a loosely arranged architecture and contained a marked cellular infiltrate. From the results of the present study it was concluded that the morphological expression of line 10 tumor rejection varies. Without immune cells, BCG is needed for the induction of a local inflammatory reaction, which was granulomatous in type and eventually led to complete tumor cell eradication.(ABSTRACT TRUNCATED AT 400 WORDS)

Rejection of cultured thyroid allografts by the transfer of sensitized LYT 2+ T cells.

Cultured BALB/c (H-2d) thyroid allografts, which are accepted permanently in fully immunocompetent allogeneic CBA/H (H-2k) recipients, are rejected following the transfer of immune spleen cells generated by immunization of recipient-strain mice with P815 (H-2d) which, like the cultured thyroid, expresses only class I major histocompatibility (MHC) antigens. Depletion of Lyt 2+ T cells from the transferred population abolished the capacity of immune spleen cells to trigger rejection, whereas depletion of L3T4+ T cells was without effect. Transfer of in-vitro-activated H-2d specific Lyt 2+ T cells also triggered rejection of cultured thyroid allografts. The results are consistent with previous studies showing that sensitized Lyt 2+ T cells are required for rejection of cultured pancreatic islet allografts, which also express only class I MHC antigens. These results are in accord with the notion that Lyt 2+ T cells are activated by and are active against class I MHC antigens.

Monoclonal Antibodies to Human β-Interferon Produced by Adoptive Transfer in Irradiated Mice

Three murine anti-human beta-interferon (IFN-beta) monoclonal antibodies have been isolated following adoptive transfer of immune spleen cells. Adoptive transfer was used to increase the specific efficiency of the fusion. These antibodies have been used to define two epitopes on IFN-beta; the antiviral, antiproliferative, and immunomodulatory effects of IFN-beta are associated with one of these epitopes.