Capacity Of Spleen Cells Research Articles

Protection of mice previously infected with Plasmodium vinckei against subsequent Salmonella enteritidis infection is associated with nitric oxide production capacity.

When mice previously cured of a Plasmodium vinckei infection were subsequently infected with Salmonella enteritidis the course of bacterial infection was significantly retarded, showing increased survival duration as compared with control infections in naive mice. Moreover, on stimulation with lipopolysaccharide and/or interferon-gamma, spleen cells from malaria-cured mice showed an increased capacity to produce tumor necrosis factor, interleukin 6, and reactive nitrogen intermediates as compared with spleen cells from naive mice. However, no significant variation in the capacity of spleen cells to release reactive oxygen intermediates was observed between previously malarious and naive mice. The most significant increases were observed in the capacity for reactive nitrogen intermediate production after P. vinckei malaria. These results suggest that the observed protection of mice against salmonellosis in the convalescent phase after malaria may be mediated by nitric oxides.

Immunological Events during the Early Phase of Infection with Schistosoma Mansoni in Mice

Naturally occurring infection in humans or experimental infection in mice by Schistosoma mansoni lead to a Th1 towards Th2 switch of cytokine response in the chronic late phase of the disease. It has been proposed that an initial Th1 response is successively down-regulated and followed by an egg-antigen driven Th2 response. Here we report the results of a kinetic study on the capacity of spleen cells from experimentally infected Balb/c mice to produce Th1 or Th2 cytokines, following mitogen stimulation, during the phase which precedes the granulomatous response associated to egg-deposition. The main results were identified as an early increase in IL-4 and IL-10 Th2 cytokine production, particularly pronounced for IL-10, only a slight and delayed decrease in IL-2 production and an invariable or actually enhanced capacity to produce IFN-γ. The emergence of Th2 response was associated with only slight and delayed modifications in spleen lymphocyte subsets, mainly represented by a decrease in CD3+ T cells and an increase in B cells. The initial unbalance of the Th1/Th2 response precedes thus the egg-deposition and the chronic phase of the infection, being evident 3 weeks after the challenge with the parasite. This observation could represent a novel finding useful in understanding the complex mechanisms involved in the immunopathogenesis of schistosomiasis.

CD3 antibody-induced dominant self tolerance in overtly diabetic NOD mice.

Low doses of the CD3 mAb 145 2C11 restored self tolerance to beta cell Ags in adult overtly diabetic NOD mice. Within 2 to 4 wk after treatment, complete and permanent remission of diabetes was observed. Autoreactive T cells were not deleted in CD3 Ab-protected animals as evidenced first, by the persistence of peripheral insulitis and, second, by the capacity of spleen cells from CD3 Ab-treated mice to transfer diabetes to adult irradiated syngeneic recipients. Moreover, the conferred tolerance was reproducibly reversed by a single injection of cyclophosphamide. For 5 to 7 wk after treatment, IFN-gamma production by stimulated spleen cells was significantly decreased in treated animals. One unique feature was that the CD3 Ab-induced tolerance ensued only from treatment of overtly diabetic NOD mice. Durable protection was exclusively observed when treating mice with recent onset disease (14-20 wk old). At variance with this finding, treatment of 4- and 8-wk-old mice was without effect, and complete but transient protection followed the treatment of 12-wk-old NOD mice. The tolerogenic properties of 145 2C11 did not depend on its mitogenic capacity, since nonmitogenic F(ab')2 fragments also appeared potent at inducing durable remission in overtly diabetic NOD, although nonmitogenic CD3 F(ab')2 fragments could mediate T cell signaling, as evidenced by cytokine gene transcription (IL-2, IFN-gamma, IL-4, and IL-10) assessed by PCR on splenocytes from treated mice. A concomitant cyclosporine treatment abrogated the CD3 mAb-induced protection, further pointing to the crucial role of T cell signaling in the effect observed.

Spleen cells from antithymocyte serum pretreated mice do not induce GVHD but exert increased repopulating activity in irradiated semiallogeneic recipients.

Graft-versus-host disease (GVHD) due to allogeneic bone marrow transplantation can be prevented by depleting the T cells from the marrow graft in vitro. However, the elimination of the donor T cells results in a higher frequency of graft failure, secondary infections and, in case of leukaemia, relapse. We found, that, in contrast to normal spleen cells, spleen cells from A or B10 donor mice pretreated with xenogeneic antithymocyte serum (ATS) in vivo did not induce GVHD in non-irradiated (B10 x A)F1 hybrids. Spleen cells of ATS-pretreated A donors did not cause GVHD in allogeneic CBA mice made neonatally tolerant to the A donor strain either. Furthermore, spleen cells from ATS-treated donors did not cause GVHD in irradiated F1 hybrid recipients, moreover, they decreased the lethal effect of irradiation. The in vivo ATS pretreatment improved the repopulating capacity of spleen cells in irradiated syngeneic recipients, too. The effect of the ATS treatment does not rely solely upon the elimination of T cells, since flow cytofluorometric analysis revealed only a partial depletion of both the CD4+ and CD8+ T cells of the ATS-pretreated animals. These observations may also have clinical relevance.

IFN-gamma, but not IL-4, synthesis by antigen-primed murine T cells is IL-2 dependent. Differential requirements in de novo and established responses.

Ag-induced, CD4 T cell-dependent synthesis of IL-4 and IFN-gamma plays a critical role in the induction, maintenance, and regulation of allergic responses. The requirement for IL-2 and IL-4 in the initial induction of IL-4 T cell responses is well established. However, it remains unclear whether IL-2 is required for priming of IL-4 responses, IL-4 gene expression, or both. In this report, we dissociate the IL-2 dependence of developing and established IL-4 responses. The capacity of spleen cells from naive and allergen-immunized mice to synthesize IL-4 after Ag-specific vs polyclonal restimulation is examined in overnight cultures. Although de novo induction of IL-4 and IFN-gamma production obtained after in vitro activation of cells from naive animals with immobilized anti-CD3 is IL-2 dependent, Ag-driven IL-4 synthesis by CD4 T cells from OVA (alum)- or ragweed extract (alum)-immunized mice is independent of IL-2. The data demonstrate the IL-2 independence of CD4 T cell-derived IL-4 synthesis by allergen-primed cells, distinguishing IL-2-dependent from IL-2-independent stages of IL-4 responses. In contrast to the finding that IL-2 is not required for IL-4 gene expression by primed T cells in allergen-driven responses, both induction and expression of IFN-gamma responses are strictly IL-2 dependent. This differential requirement for IL-2 in IL-4 and IFN-gamma gene expression may be significant in the maintenance of IL-4-dominated responses in allergic individuals.

In vivo treatment with anti-I-A antibodies: differential effects on Ia antigens and antigen-presenting cell function of spleen cells and epidermal Langerhans cells.

The in vivo activation of T cells by a variety of antigens can be inhibited by the administration of anti-I-A antibodies (Ab) at the time of antigen priming. This inhibition can partially be explained by the temporary loss of Ia molecules from Ia-bearing antigen-presenting cells (APC) in the spleen. In this study, the effects of i.p. injected monoclonal Ab specific for I-A glycoproteins of different H-2 haplotypes on Ia antigen expression and APC function of spleen cells and epidermal Langerhans cells were compared. It was found that anti-I-A Ab quickly bound to both spleen cell and Langerhans cell Ia antigens. Although spleen cell Ia antigens were modulated and thus temporarily disappeared, Ia antigen expression by epidermal Langerhans cells was not modulated. In functional studies, the capacity of spleen cells and epidermal cells from anti-I-A Ab treated vs control animals to function as APC for antigen-specific, I-A- or I-E-restricted T cell clones was tested. A single injection of anti-I-A Ab completely abolished the APC function of spleen cells as shown in several inbred mouse strains, F1 animals, and with the use of several different Ab and T cell clones. In contrast, Langerhans cell-dependent APC function of epidermal cells remained completely unaltered. Even multiple injections of high doses of Ab never caused any inhibition of Langerhans cell function. Experiments with anti-I-Ak or anti-I-Ad Ab in an (H-2k X H-2d)F1 animal showed abrogation of APC function of spleen cells, but again not of Langerhans cells. Thus in vivo anti-I-A Ab administration appears to differentially affect Ia antigen expression and APC function from spleen and epidermis: Ia antigens are modulated from spleen cells but not from epidermis, and APC function disappears in the spleen but not in the epidermis. The abrogation of splenic but not of Langerhans cell APC function with anti-I-A Ab will facilitate the dissection of the relative contributions of Langerhans cells as compared with other APC in the generation of cutaneous immune responses.

Natural killer cell activity and spontaneous development of lymphoma. Effects of single and multiple injections of interferon into young and aged C57BL/6 mice

The capacity of interferon (IFN) given once or repeatedly to augment natural killer (NK) cell activity in the spleen was tested in young and aged C57BL/6 mice. Multiple injections of 10(4) u IFN i.p. into 3-month-old or 12-month-old mice did not augment cytotoxicity mediated by NK cell activity; rather it reduced this activity in relation to the effect obtained with a single injection. When T and B cells or macrophages were removed in vitro, no restoration of NK-cell activity, and therefore no suppressor cells, could be found in this system. In a long-term experiment, B6 mice were chronically injected with 10(4) u of IFN or mock-IFN from 5 months of age until death. No difference in the modification of NK-cell activity was observed after IFN and mock-IFN, regardless of the duration of treatment. However, the capacity of spleen cells to generate cytotoxic T cells after allogeneic stimulation in vitro or in vivo was increased in IFN-treated mice. The median survival time was improved by 7 weeks through treatment with IFN compared to mock-IFN, but was reduced by 9 weeks compared to the survival after treatment with saline. No significant difference in the incidence of spontaneous lymphoma resulted from IFN treatment, but the percentage of tumors observed in mice receiving mock-IFN (68.1%) was higher than that in mice receiving saline (44.1%). These results indicate that, while a stimulating effect resulting in a delay in mortality and in tumor development can be attributed to IFN itself, the contaminating antigenic products are plausibly responsible for the deleterious effect of the total preparation.

Adherent spleen cells from mice acutely infected with cytomegalovirus suppress the primary antibody response in vitro.

In the present study, we have demonstrated that the hemolytic plaque response of spleen cells from mice acutely infected with murine cytomegalovirus (MCMV) is suppressed in vitro. Mishell-Dutton cultures established with spleen cells from C57BL/6 mice infected 4 days earlier with 4.2 X 10(3) plaque-forming units of MCMV were found to produce significantly fewer direct plaques upon stimulation with sheep red blood cells than corresponding control cultures. Suppression could not be attributed to a generalized lytic destruction of spleen cells, nor was it produced by addition of virus directly to uninfected spleen cell cultures. However, in cultures containing various mixtures of cells from control and infected mice, the direct plaque response was markedly below the predicted response, suggesting that the uninfected cells were actively suppressed by cells from infected mice. Suppression was dependent on the presence of intact spleen cells, since it was not found in the presence of lysed cells. The capacity of spleen cells from infected mice to mediate suppression was demonstrated in the plastic-adherent subpopulation. Treatment of these cells with anti-thymocyte serum (ATS) and complement did not abolish the capacity to suppress the immune response. Thus, adherent ATS-resistant cells from the spleens of mice acutely infected with MCMV, rather than virus alone, have the capacity to actively suppress the hemolytic plaque response in vitro.

Spontaneous lytic activity against allogeneic tumor cells and depression of specific cytotoxic responses in mice infected with Trypanosoma cruzi.

The ability of cells from mice infected with Trypanosoma cruzi to generate specific as well as nonspecific cell-mediated cytotoxic responses to allogeneic tumor cells was investigated. The capacity of spleen cells from either C3H/He (C3H) or C57BL/6 (B6) mice to develop cytotoxic responses in vitro against P-815 tumor cells was depressed after the 2nd wk of acute infection initiated with 10(3) parasites. However, spleen cell responses in B6 mice sensitized against P-815 were depressed only in those mice infected for 16 to 22 days and were significantly enhanced in mice infected for shorter or longer periods of time. In subsequent experiments, significant cytotoxic activity against P-815 target cells was observed in cells from infected B6 and, to a lesser degree, C3H mice without prior sensitization with the tumor cells. With the use of both P-815 and YAC tumor cell lines in cytotoxicity assays, two phases of apparently nonspecific T. cruzi-induced lytic activity (TILA) were observed after infection: a 1st phase detected within 2 days against YAC target cells, and a subsequent phase detected against both YAC and P-815 target cells at a time dependent upon the number of parasites injected. Other results demonstrated increased cytotoxic activity against P-815 target cells in 2.5-mo-old C3H mice infected with greater numbers of T. cruzi or when older (4.5 to 6.5 mo) mice were infected with 10(3) parasites. Antibodies cross-reactive to tumor cells were not detected in sera from infected mice, suggesting that TILA is an antibody-independent phenomenon. Possible relationships between the phases of TILA and the modification of specific responses generated in infected mice are discussed.

Activation of Specific Cellular Immunity toward Murine Leukemia in Mice Rejecting Syngeneic Somatic Hybrid Cells

Abstract ASL-1 × LM(TK)- somatic hybrid cells form both H-2a and H-2k antigen complexes. After forming a localized tumor in syngeneic (A/J × C3H/HeJ)F1 mice, they are rejected. Such mice are resistant to otherwise invariably lethal injections of ASL-1 cells, surviving for prolonged and, in some instances, indefinite periods. To examine the basis of immunity, the capacity of spleen cells from mice rejecting hybrid cells to stimulate the release of 51Cr from labeled ASL-1 cells was investigated. Cells from the spleens of mice rejecting ASL-1 × LM(TK)- cells stimulated the release of 51Cr from labeled ASL-1 cells, but not from Ehrlich ascites or P815 cells. Cells from mice injected with mitomycin-C-treated ASL-1 cells led to the release of 51Cr from labeled ASL-1 cells as well, but the extent of 51Cr release was approximately one-third as occurred in the presence of cells from hybrid cell-injected mice. Cells from noninjected mice or from mice injected with LM(TK)- cells failed to lead to the specific release of 51Cr from ASL-1 cells. The presence of unlabeled ASL-1 cells, but not Ehrlich ascites cells, competitively inhibited the spleen cell-stimulated release of 51Cr from labeled ASL-1 cells. Sera from A/J mice injected with mitomycin-C-treated ASL-1 cells contained antibodies specific for the tumor-associated antigen of ASL-1 cells. The specific release of 51Cr from ASL-1 cells stimulated by spleen cells from hybrid-cell injected F1 mice was inhibited by such antisera, but not by H-2a antisera. Treatment of spleen cells from mice injected with hybrid cells with Thy 1.2 antiserum before incubation with 51Cr-labeled leukemic cells reduced the proportion of 51Cr released by approximately one-half. Spleen cells from animals injected with hybrid cells, as well as to a lesser extent from noninjected mice, which are capable of adhering to plastic Petri dishes were active in the cytotoxic reactions as well. Results similar to these were obtained with 51Cr-labeled RADA-1 cells, a radiation-induced leukemia of A/J mice and spleen cells from (A/J × C3H/HeJ)F1 animals injected with RADA-1 × LM(TK)- hybrid cells.

T lymphocyte function as the principal target of lymphocytic choriomeningitis virus-induced immunosuppression

Plaque-forming cell responses against sheep erythrocytes, Escherichia coli lipopolysaccharide, pneumococcal polysaccharide, and polyvinylpyrrolidone were examined in mice infected with lymphocytic choriomeningitis virus. A 92 to 96 percent reduction of the thymus-dependent anti-sheep erythrocyte responses was observed 2 to 4 weeks after infection. However, the thymus-independent responses against the three other antigens were close to normal at all stages of the infetion. Studies on allograft immunity of infected C3H mice against DBA/2 mastocytoma cells revealed a severe suppression of the T cell-mediated cytotoxic response which was temporally related to the impaired humoral responsiveness against sheep erythrocytes. The capacity of spleen cells from infected mice to restore immune responsiveness of lethally irradiated recipients against sheep erythrocytes was significantly reduced. The adoptive responses, however, were clearly improved when normal thymus cells were added to the inferior spleen cells. Moreover, it appeared that the spleen cells from immunosuppressed donor mice could not confer suppression to normal lymphoid cells. The presented findings are consistent with the assumption that a numeric deficiency of T cells, or cells belonging to some T cell subpopulation, is the primary cause of lymphocytic choriomeningitis virus-induced immunosuppression.

Spleen Cell Cytotoxicity in New Zealand Black Mice (NZB) with Autoimmune Disease

Abstract New Zealand black mice (NZB)2 develop disease spontaneously which is similar in many ways to human systemic lupus erythematosis (SLE) and is characterized by autoantibodies, nephritis, (1, 2) and perivascular cellular infiltration. These mice have also shown a decreased capacity with ageing to reject tumors induced by Moloney sarcoma virus (3). Cantor and co-workers (4) have demonstrated that the capacity of spleen cells from NZB mice to mount a graft-vs-host reaction also decreases with age. Both of these observations indicate reduced efficacy of the thymus-dependent immune system or thymus-dependent lymphocytes (T cells), but do not show whether programmed T cells are responsible for some of the cellular autoimmunity in this disease. We have investigated the ability of spleen cells from diseased NZB mice to elicit a cytotoxic effect against fetal target cells, in vitro, by a modified form of the colony inhibition, or lymphocyte cytotoxicity system (5, 6).

Assessment of the Radioprotective Capacity of Spleen Cells Transplanted from Mice with Rauscher Viral Leukemia

Rauscher leukemia virus infection induces a radioresistance in SJL/J mouse which is accompanied by increases in spleen cells and spleen CFUs of up to 17 times the normal. The present experiments have been carried out to directly evaluate the radioprotective ability of these spleen cells in relation to normal spleen cells. For this purpose spleen cells from both normal and leukemic mice were transplanted into lethally irradiated normal recipients. The results show that for the first 24 days after irradiation and cell transplant the radioprotective ability of the RLV-infected cells is at least equivalent to the normal. However after this time the survival curve of the recipients of RLV infected cells is adversely modified by the leukemia. Nevertheless, the number of survivors at 30 days is significantly large enough to conclude that the spleen cells of mice with Rauscher leukemia do protect against radiation caused mortality.

Immunodepression as a factor during 3-methylcholanthrene carcinogenesis and subsequent tumour growth in mice.

AbstractCBA/H‐T6 mice received a dose of 3 or 6 mg 3‐methylcholanthrene on day 0 and their spleen cell IgM antibody response to sheep red blood cells was found to be significantly depressed 23 days thereafter. However, at this time, there was no reduction in the ability of spleen cells from these mice to induce a graft‐versus‐host reaction in (A × T6)F1 hybrid animals. On day 68 after 3‐MC injection, six animals had developed tumours while six were still in the latent period. There was no difference in the capacity of spleen cells from these two groups of animals to induce a GvH reaction in F1 hybrids. Three 3‐MC induced sarcomata were serially passaged in isogenic hosts. The growth rates of these tumours increased and the regional lymph nodes and spleens became progressively more hypoplastic in successive hosts. However, there was again no decline in immunocompetence of spleen cells as judged by the induction of a GvH reaction in F1 hybrids. It is therefore suggested that the increase in tumour growth rate reflected a change in the tumour rather than increasing immunodepression of successive hosts.

The Effect of Plasmacytomas on the Immune Response of Mice

Abstract The effect of plasmacytomas on the immune response of mice was studied by examining the number of direct and indirect plaque-forming cells in the spleens of tumor-bearing animals and the capacity of spleen cells from tumor-bearing mice to immunologically reconstitute irradiated mice. These studies revealed that plasmacytomas differ in their ability to depress the primary 19S response. A γ1-producing tumor and a non-producing tumor in BALB/c mice and a γG2b-producing tumor in DBA/2 mice severely depressed the primary 19S response in mice bearing these tumors, while a γG2b-producer in BALB/c mice had either no effect or a stimulatory effect on the primary 19S response of its host. The effect of the tumors could not be correlated with the presence or absence of paraprotein production. The primary 7S response was not depressed in plasmacytoma-bearing mice. The secondary antibody response to SRC, whether primed before or after tumor implantation was unaffected in mice bearing these tumors. Spleen cells from tumor-bearing mice whose immunocompetence was depressed were capable of restoring the immune response of lethally irradiated mice. The data suggest that either the immunologically depressed cells can recover their immunocompetence upon transfer to a tumor-free host or a proportion of cells in the tumor-bearing mice retain their immunocompetence and these latter cells are responsible for the immune reconstitution of the irradiated mice.

Influence of metabolic inhibitors on the capacity of spleen cells to form hemolytic plaques and rosettes.

SummaryTreatment of normal peritoneal exudate cells with antisheep red blood cell antibodies passively immunized some of the cells (presumably macrophages), i.e., conferred on them the capacity to form hemolytic plaques and rosettes. Preincubation with puromycin inhibited plaque and rosette formation by immune spleen cells of actively immunized animals but not by passively immunized peritoneal exucate cells. Puromycin inhibited protein synthesis in both cell populations equally strongly. Sodium fluoride depressed plaque formation by immune spleen cells of actively immunized animals, but not by passively immunized cells. Sodium fluoride treatment had no effect on rosette formation by either actively or passively immunized cells.

Failure of spleen cells from thymectomized mice to induce graft vs. host reactions.

Summary1. The capacity of spleen cells from mice thymectomized during neonatal life to elicit graft vs host reactions was studied using Simonsen's graft vs host assay of histocompatibility. 2. The reaction of A strain spleen cells from mice sham operated or thymectomized in the neonatal period was compared to that of isologous F1 cells in (A × C57B1)F1 recipients and Z strain spleen cells from similarly treated groups were compared in (Z × C57B1) F1 and in the (Z × DBA/2)F1 hybrids. 3. The results show that early complete thymectomy in both A and Z mice renders the spleen cells of these animals incapable of producing graft vs host reactions in Fl hybrids. 4. These data are interpreted as evidence that the cells themselves of the lympho-reticular system in mice thymectomized at or shortly after birth are immunologically defective. 5. These observations are considered as a further evidence that the thymus plays a key role in development of immunological capacity in mammals.