Multiple forms of DNA-ase activity in the nuclei of spleen lymphocytes]

The nuclei of spleen lymphocytes showed nuclease activity becoming manifest under conditions optimal for different types of DNA-ase (DNA-ase I, DNA-ase II, micrococcal nuclease and Ca, Mg-dependent endonuclease). No diversity of nuclease activity was found in the liver or kidney nuclei. A high nuclease activity in the lymphocyte nuclei provides for a deeper endonucleolysis of the lymphocyte chromatin as compared to that in the liver nuclei. The variety of nucleic activity and more advanced chromatin endonucleolysis in the spleen lymphocyte nuclei may be associated with rapid cell renewal of the lymphocyte pool in lymphoid organs and with necessity for autolysis of degraded lymphocyte genome. It may also ensure the somatomutagenic mechanism of diverse V-genes and of V- and C-gene combination.     

当归内酯对免疫抑制小鼠免疫功能的重建作用(英文)

探讨当归内酯(ASDL)对免疫抑制小鼠免疫功能的重构作用。通过小鼠腹腔注射环磷酰胺建立免疫抑制动物模型。采用免疫器官重量法和小鼠腹腔巨噬细胞吞噬鸡红细胞实验检测了ASDL对非特异性免疫功能的影响;用血清溶血素分光光度法检测了对体液免疫功能的作用;用MTT法进行了致分裂原诱导的小鼠脾淋巴细胞的增值反应实验,再用乳酸脱氢酶法测定了NK和CTL细胞活性,从而确定ASDL对小鼠细胞免疫功能的影响。结果表明:ASDL能够对免疫低下小鼠的非特性和特异性免疫功能起到一定的重构作用。但是这种效果并不是剂量依赖性的,20 mg/kg这个剂量的效果明显好于5和80 mg/kg这两个剂量。上述结果表明ASDL能够显著提高免疫低下小鼠的免疫功能。     

Morphologic and biochemical changes in the lymphoid and hematopoietic tissues of rats with Zajdela hepatoma

The growth of allogeneic ascites hepatoma is accompanied by involution of the thymus, leukemoid response and anemia. Tumor cells disseminate throughout the body appearing in many organs including the spleen, liver, bone marrow and lymph nodes. The activity of adenosine deaminase and the adenosine deaminase/purine nucleosidephosphorylase ratio decrease in the host thymus as well as in the cellular elements of the spleen. The above phenomena reflect the impairment of lymphocyte differentiation and presumably contribute to the decreased efficiency of the host immune response.     

凝结芽胞杆菌对免疫功能影响的实验研究

目的 研究凝结芽胞杆菌（TQ33）对实验动物免疫功能模型的影响。方法 以鸡红细胞混悬液对小鼠腹腔注射,观察TQ33对小鼠腹腔巨噬细胞吞噬功能的影响;制备绵羊红细胞（SRBC）,观察血球凝集程度,测定血清溶血素;以靶细胞（YAC-1细胞）与脾细胞（效应细胞）的反应检测TQ33。对小鼠NK细胞活性的影响;采用淋巴细胞转化法观察TQ33对细胞免疫的影响;计算小鼠胸腺／体重及脾脏／体重为脏器系数观察TQ33对小鼠脏器的影响。结果 与对照组比较,TQ33显著增加小鼠腹腔巨噬细胞吞噬功能;对小鼠体液免疫功能有一定的增强作用;可增强小鼠NK细胞活性;对ConA诱导下的小鼠淋巴细胞转化有增强作用;对脏器系数没有显著的影响。结论 凝结芽胞杆菌具有明显的免疫调节作用,预示有良好的应用前景。     

Plasmodium berghei: immunosuppression of the cell-mediated immune response induced by nonviable antigenic preparations

In this work, plasmodial antigens were examined for their ability to suppress the cellular immune response during lethal Plasmodium berghei infection. Splenic enlargement and the number and function of white spleen cells were assessed after injection of normal mice with irradiated parasitized erythrocytes (IPE) or with parasitized erythrocytes (PE) membranes. Both IPE and PE membranes caused splenomegaly and an increase in the number of splenic white cells with concurrent alteration of the relative proportions of T cells and macrophages. The percentage of T lymphocytes was fractionally diminished, but there was a marked increase in Lyt 2.2 positive (suppressor and cytotoxic) T subsets and in the number of splenic macrophage precursors. The pathological enlargement of the spleen was induced by various plasma membrane-derived antigens containing both proteins and carbohydrates. Splenocytes of mice injected with liposomes containing deoxycholate-treated PE or PE fractions showed both diminished interleukin 2 production and a decreased response to mitogen. It appears that some of the changes in the cellular immune response during P. berghei infection are a consequence of the massive provision of a wide spectrum of antigens, capable of suppressing the immune response. Thus, it may be appropriate to evaluate the possible negative effect of parasite epitopes that are candidates for vaccine.     

Enhancement of the DNA synthetic response of antigen-primed lymph node cells by splenic promoter cells: characterization of the splenic promoter cells.

Rabbits were immunized in the footpad with diphtheria toxoid in complete Freund's adjuvant. At various times after immunization, cells harvested from the spleen, the draining (immune) and the opposing (control) lymph nodes (LN) were assayed for their proliferative response to incorporate tritiated thymidine upon exposure to the priming antigen. Although the immune LN cells responded by a substantial incorporation of thymidine, cells from the control LN and the spleen either did not respond or responded feebly. An enhancement in the response of the immune LN cells was observed when they were cultured in the presence of nonresponsive spleen cells. Pretreatment of spleen cells with mitomycin C did not abolish the enhancement. This suggests that the target cells which respond to the antigen are derived from the immune LN whereas the promoter cells which enhance the response are present in the spleen. The removal of adhering cells by glass wool columns and of Ig-bearing cells by anti-Ig immunoabsorbent columns from the spleen did not reduce the enhancing capacity of the nonadhering cells. Conversely, the killing of splenic T cells by specific heterologous antiserum directed against rabbit thymus lymphocyte antigen abolished the enhancement. Thus, the promoter cell which facilitates the enhancement has been characterized as a nonadherent, splenic T cell.     

Effects of C-reactive protein on the lymphoid system. II. Inhibition of mixed lymphocyte reactivity and generation of cytotoxic lymphocytes.

C-reactive protein (CRP), an acute phase reactant which increases in concentration during inflammation, has been found to bind to human T cells and to inhibit certain of their functions. In the present study CRP was found to display a binding specificity for theta-bearing cells from mouse peripheral lymphoid tissue but not for thymus cells. CRP inhibited the proliferative response in a similar manner in both murine and human mixed lymphocyte reactions. This inhibition was prevented by the addition of the CRP substrate, pneumococcal C-polysaccharide (CPS), and was not a result of toxicity of CRP for lymphocytes. By contrast the response of spleen lymphocytes to mitogenic Con A concentrations was not altered by CRP. CRP also exerted an inhibitory effect on the in vitro generation of cytolytic T lymphocytes (CL) in mixed lymphocyte reactions of mouse spleen cells. The expression of the cytolytic process by T cells sensitized either in vivo or in mixed lymphocyte cultures was not altered in the presence of CRP. Therefore, CRP appears to influence the inductive phase of the allograft response and perhaps exerts a regulatory effect on cellular immune responsiveness during inflammatory reactions.     

Interference with the transmission of T cell-derived messages by macrophage membranes.

Heat-killed macrophages (HK Mphi) and/or semi-purified Mphi membranes interfere with primary thymus-dependent but not thymus-independent in vitro immune responses. In addition, they can absorb out and render inactive the helper activity found in mixed lymphocyte culture supernatants which augments the primary in vitro response of normal spleen cells. They do not, however, inactivate the helper activity which augments the response of thymus-deprived spleen cells. Both the immunologic interference and the absorbing activity of the HK Mphi are eliminated by treatments which inactivate or block Fc receptors. We suggest that HK Mphi or their membranes can act as competitive antagonists for live Mphi functions and in so doing block communication networks between T cell subclasses. Thus they can serve as useful probes both for studying some of the roles live Mphi might play in mediating immunologic functions as well as dissecting out some of the many arcane T cell interactions which normally occur.     

Specific, transient suppression of the immune response by HGG tolerant spleen cells. II. Effector cells and target cells.

In a previous report, it was shown that spleen cells from mice made tolerant to human gamma-globulin (HGG)5 could specifically inhibit the immune response of normal spleen cells after adoptive transfer to lethally irradiated recipients. However, that report also showed that the suppressive activity was only transiently associated with tolerant spleen cell populations. It was concluded from those experiments that while suppressive activity could be demonstrated in tolerant spleen cells under certain conditions, such activity was not obligatory for the maintainance of the tolerant state. The experiments presented here were performed to determine the nature of the effector cell(s) and the target cell(s) involved in this system of suppression of the immune response. Treatment of cells from tolerant animals with anti-thymocyte serum and complement to remove thymus-derived (T) cells completely abrogated suppresive activity. Removal of adherent cells from tolerant spleen cells by passage over glass wool columns resulted in partial loss of the suppression. The inhibitory activity of the suppressor cells was resistant to 900 R irradiation regardless of whether the tolerant spleen cells were irradiated before or after adoptive transfer. The cellular target(s) for the supprssor cells was examined by using lipopolysaccharide (LPS) as an alternative source of helper activity for the response to HGG. LPS, injected at the time of the initial antigenic challenge of mice that had been reconstituted with tolerant and normal spleen cells, prevented the expression of suppression against bone marrow-derived (B) cells. However, when LPS was presented only at the time of secondary antigenic challenge, it was unable to overcome suppression of the immune response of reconstituted recipients. Thus, LPS could produce a state where the B cells were resistant to suppression, but LPS could not rescue the responsiveness of B cells once the cells in the reconstituted recipient had been suppressed. In addition, the immune response to both the hapten dinitrophenol (DNP) and the carrier (HGG) were suppressed when recipients of tolerant and normal spleen cells were challenged with DNP6HGG. This indicates that T helper cells are also a target for suppression. The results presented in this paper are discussed in relation to a possible mechanism of suppression which proposes that suppressive activity represents the induction of tolerance in immunologically competent cells by HCG which is closely associated with the tolerant spleen cells.     

Model system for study of cell interactions and mechanisms of immune response to T-independent antigens of type 2 in vitro

Cellular mechanisms of immune response to type 2 T-independent antigens (TI-2 antigens) are not fully elucidated up till now. In vitro system is the most convenient model for such studies. However, in vitro model requires relatively high cell density in the cultures. It hampers the study of minor lymphocyte subsets like CD5+ B-1 splenocytes, which play the main role in the immune response to TI-2 antigens. The use of cell mixtures of normal and immunodeficient congenic animals may help to resolve this problem. In this work, immune responses to TI-antigens of type 1 (TI-1 antigens) and to TI-2 antigens in vitro were studied in the mixtures of cells of normal (CBA) and congenic xid-mice (CBA/N). CBA/N mice lack CD5+ B-1 cells and do not respond to TI-2 antigens. Therefore, their splenocytes can be used as “filler” cells to create the optimal cell density in the cell cultures. Spleen and peritoneal cells of CBA mice and B-1 and B-2 lymphocytes isolated from peritoneum and spleen, respectively, were cultured in different proportions with CBA/N splenocytes with or without antigens. LPS and polyvinylpyrrolidone (PVP) were used as TI-1 and TI-2-antigens, respectively. Antibody- and immunoglobulin-forming cells (AFC and IFC, respectively) were determined by the ELISPOT method on the 4th day of cultivation. It was shown that CBA and CBA/N cells in mixed cell cultures retained their functional activity. Splenocytes of CBA mice responded to both TI-antigens. Splenocytes of CBA/N mice responded to TI-1 antigen (LPS) only. It means that in vitro B-1 cells play the main role in the immune response to TI-2 antigens, as they do in vivo. Thus, the developed model system can be used to study cellular mechanisms of immune response to TI-1 and TI-2 antigens in vitro.     

Stimulating effect of polyion on the production of cytolytic T lymphocytes in a cell culture in vitro

Introduction of polyion "vegetan" at the concentrations varying from 20 to 100 micrograms/ml into mixed lymphocyte culture (MLC) with insufficient antigenic stimulus, low immunogenic MLC, for the whole of the incubation period, leads to 30-70% increase in T-lymphocyte cytolytic activity. The effect of vegetan on the cytolytic activity of T-lymphocytes from normal MLC is less marked. In the in vivo model of primary synthesis of antibodies against heterologous erythrocyte antigens, vegetant causes 20-50-fold enhancement of a weak immune response compared to 1.5-2-fold when the latter approaches the highest levels. These findings indicate an inverse relationship between the immunostimulating activity of vegetan and the levels of the immune response, the latter being the target of activation. Vegetan was shown to induce more than 2-fold increase in the proliferation in both types of MLC as well as in mouse spleen lymphocyte monoculture. It is reasonable to propose that the preparation may stimulate the proliferation of both T-killers and other lymphocyte subpopulations.     

The annual involution and regeneration of the thymus in hibernating animals and perspectives of its studies in gerontology and stem cell proliferation

Data on a unique phenomenon of annual involution and neogenesis of thymus gland in hibernating animals are reviewed. In accordance with morphological findings, the annual thymus involution in hibernating animals is close to the age-dependent thymus involution occurring in all mammals once in a lifetime. In opposite, thymus involution in hibernating animals is totally different from the accidental involution. During hibernation, the thymus tissue is substituted by the brown fat tissue. In the spring, thymus gland neogenesis stats with intensive growth of epithelial tissue followed by lymphocyte infiltration and exhaustion of brown tissue. Morphological changes in the thymus gland within the annual cycle were compared with seasonal dynamics of structural and functional changes in peripheral lymphoid organs (spleen, lymphoglandular, peritoneal fluid). A general regularity was observed involving a decreased functional activity of immune cells in autumn, its sharp depression during winter hibernation, and obvious increase in summer with the onset of a season of animal activity. It is supposed that a sharp increase in the tumor necrosis factor (TNF) production observed during short-term awakenings in winter may serve an important link in this unique immune adaptation mechanism. The season changes in cellular TNF secretion suggest a mobilization of protective resources in hibernating animals in autumn and winter, i.e. in seasons when the thymus gland activity is depressed. The annual involution of thymus gland cannot be related to droppings in the environmental or body temperatures, as it comes long before their fall. Additionally, it is not related to ageing, as it occurs already in young hibernating animals. The role of hormones, including melatonine and corticosteroids, in mechanisms regulating thymus gland involution in hibernating animals is discussed.     

Mechanism of formation of antibody production stimulating ability of bone marrow cells of mice immunized with staphylococci

The mechanism of the increase in immune response to particular staphylococcal antigen was studied in CBA and BALB/c mice injected by primed bone marrow cells (BMC). It was found that immunostimulatory effect of immune BMC is not mediated by macrophages or T cells, but is associated with staphylococcus-specific B memory cells present in the pool of primed BMC. Splenectomy performed in donor animals prior to immunization did not abolish the induction of stimulating BMC activity. It was concluded that primed B lymphocyte migration from spleen into bone marrow is not obligatory for the induction of staphylococcus-specific immunological memory in the bone marrow.     

Cell-mediated cytotoxicity of lymphocytes from chickens inoculated with herpesvirus of turkey against a Marek's disease lymphoma cell line (MSB-1).

Using a new device which increases the sensitivity of detection of specific immune lysis of target cells by labeling them with [35S]-methionine, the in vitro cell-mediated cytotoxic response of spleen lymphocytes and peripheral blood lymphocytes from chickens vaccinated with herpesvirus of turkey (HVT), O1 strain, against MSB-1 line cells was clearly demonstrated. The cytotoxic activity was clearly inhibited by pretreatment of effector lymphocytes with anti-T lymphocyte serum and complement. The activity was greater using T cells purified from spleen lymphocytes and peripheral blood lymphocytes than with the unfractionated cells, indicating that T lymphocytes play the main role in effector activity. Using sera from HVG-vaccinated chickens, no significant cytotoxic effects were detected in the complement-dependent antibody cytotoxicity test against MSB-1 cells. These results suggest that cellular immunity against the surface antigen of Marek's disease (MD) lymphoma cells is mainly related to the preventive mechanism against MD incidence by HVT vaccination.     

Immune response of CBA mice in postnatal ontogeny

Changes in the pattern of immune response of the CBA mice during postnatal ontogenesis were studied on the models of cellular and humoral immunity. The functions mediated by the amplifier cells were shown to undergo the most significant changes. This was confirmed by a decrease in the activity of antigen-nonspecific T-suppressors, as estimated in a semisyngeneic system, an increase in the capacity of spleen lymphoid cells to induce the "graft versus host" reaction with the age and preservation of the function of hypersensitivity effectors of delayed type at the same level (after the age of 3-4 months). It is suggested that these changes might cause an age decrease in the suppressor activity of T-cells in a response to insoluble antigens.     

Studies of the immunological capacity of germfree mouse radiation chimeras. III. In vitro reconstitution of the T-helper cell deficiency

The plaque-forming cell (PFC) response of long-term radiation induced allogeneic bone marrow chimeric (ABMC) mice has been shown to be markedly deficient. The nature of the cellular deficiency of the primary PFC response was investigated using in vitro culture techniques. Adherent spleen cells from ABMC or DBA/2 mice support equally well the development of PFC from nonadherent DBA/2 spleen cells. Nonadherent cells prepared from ABMC mice when cocultivated with DBA/2 adherent cells showed a minimal response. However, the addition of activated DBA/2 T cells to cultures containing adherent cells from DBA/2 mice and nonadherent cells from ABMC mice completely reconstituted the in vitro response to sheep erythrocytes. Therefore a cellular deficiency of the humoral immune system of ABMC mice was shown to be associated with the thymus-derived lymphocyte pool.     

Influence of the thymus extract on the immunological function of animals with experimental diabetes

After immunization with SRBC, the number of plaque-forming cells (PFC) in the spleen of alloxan-diabetic mice, in nondiabetic TIR mice and in alloxan-diabetic TIR mice was significantly decreased as compared with control non-diabetic donors. The ability of lymphocytes from alloxan-diabetic mice to adoptively restore the suppressed immune response of TIR mice, was reduced in comparison with the effect of lymphocytes from normal, nondiabetic donors. Local GVH reaction in nondiabetic rat recipients provoked by lymphocytes from control healthy mice was 5.6 +/- 0.7 mm. Significantly lower rate of local GVH reaction after injection of lymphocytes from diabetic donors was found in diabetic as in nondiabetic recipients as well. Treatment of alloxan-diabetic mice with thymus extract or with insulin, partly restored depressed function of the humoral and cellular system. Treatment of diabetic mice with both thymus extract and insulin, was even more effective in restoring of their immune reactivity. Diabetic condition strongly influenced the function of the immune system. This could be attributed to depletion of T-lymphocytes, changed relations between the lymphocyte subpopulations in diabetic donors, and disturbance of lymphocyte metabolism.     

Modulation of the immunosuppressive effects of splenic macrophages in Fischer rats bearing adenocarcinoma 13762

Summary The nature of spleen cells in Fischer rats bearing a large size (>1 cm diameter) mammary adenocarcinoma 13762A (MAC) which block the immunostimulating capacities of MTP² (a synthetic immunomodulator) and suppress proliferation in vitro of splenic T and B lymphocytes by their respective mitogens was investigated. Splenic macrophages were recognized as the suppressor cells by (a) restoration of mitogenic responses by depletion of macrophages from spleen cell suspensions and (b) continued suppressor activity in spleen cell suspensions of tumor bearers devoid of viable T lymphocytes. Macrophage contact with T lymphocytes was required for the inhibition of T lymphocyte proliferation by concanavalin A as shown by (a) the absence of suppressor activity in supernatants derived from cultured suppressor macrophages, (b) lowering of the suppressor activity of intact macrophages after treatment with neuraminidase, (c) lowering of the suppressor activity of macrophages by addition of red cells to spleen cultures of tumor bearers indicating red cell interference with macrophage-T cell interaction and (d) lack of inhibiting action of suppressor macrophages on allogenic T lymphocyte proliferation showing macrophage T cell recognition for suppression.Animals bearing a large size tumor exhibited spleen hypertrophy and an increase in macrophage:lymphocyte ratio and a decrease in red cell:lymphocyte ratio. Splenic macrophages did not appear to be implicated in blocking antitumor immunity induction since (a) suppressor macrophages were absent in spleens during the inductive phase of the immune response and (b) MAC implanted in allogenic Wistar rats grew to about 2 cm diameter, induced splenic suppressor macrophages but the tumor was later rejected by the animals. Collectively the results suggest that suppressor macrophages are the result of increasing tumor volume rather than its cause.This study was supported by a grant from the National Cancer Institute of Canada Abbreviations used: Con A, Concanavalin A; LPS, lipopolysaccharide; PHA, phytohemagglutinin; MTP, maltose tetrapalmitate; MAC, mammary adenocarcinoma 13762; RPMI, Roswell Park Memorial Institute; TBR, tumor bearing rat; RBC, red blood cell     

The role of thymus gland in the regulation of the activity of peripheral T-lymphocytes in the process of spontaneous blastogenesis in mice

The total count, spontaneous proliferation and proliferative response of thymic and spleen T-cells in mixed lymphocyte culture and Con A-induced suppressor activity do not reveal significant disorders in 10-14-month A/Sn and C3H/He mice with spontaneous mammary tumors (weight under 2-3 g). However, these indices are quite different in varying age (2, 6, 12 month) A/Sn mice and C57Bl/6 mice with low rates of spontaneous tumors. The analysis of thymus-dependent immunity changes observed with age shows that relatively intensive migration of nonmature thymocytes, T-suppressor precursors is noted in mice with high cancer incidence. This phenomenon is considered to be one of major mechanisms regulating immune response in spontaneous-carcinogenesis.     

Murine isolated lymphoid follicles contain follicular B lymphocytes with a mucosal phenotype

Isolated lymphoid follicles (ILFs) are organized intestinal lymphoid structures whose formation can be induced by luminal stimuli. ILFs have been demonstrated to act as inductive sites for the generation of immune responses directed toward luminal stimuli; however, the phenotype of the immune response initiated within ILFs has largely been uninvestigated. To gain a better understanding of the immune responses initiated within ILFs, we examined phenotypic and functional aspects of the largest cellular component of the murine ILF lymphocyte population, B lymphocytes. We observed that murine ILF B lymphocytes are composed of a relatively homogenous population of follicular B-2 B lymphocytes. Consistent with their proximity to multiple stimuli, ILF B lymphocytes displayed a more activated phenotype compared with their counterparts in the spleen and Peyer's patch (PP). ILF B lymphocytes also expressed higher levels of immunomodulatory B7 and CD28 family members B7X and programmed death-1 compared with their counterparts in the spleen and PP. ILF B lymphocytes preferentially differentiate into IgA-producing plasma cells and produce more IL-4 and IL-10 and less interferon-gamma compared with their counterparts in the spleen. Immunoglobulin repertoire analysis from individual ILFs demonstrated that ILFs contain a polyclonal population of B lymphocytes. These findings indicate that murine ILFs contain a polyclonal population of follicular B-2 B lymphocytes with a phenotype similar to PP B lymphocytes and that, in unchallenged animals, ILFs promote immune responses with a homeostatic phenotype.