反义c-myc寡核苷酸抑制大鼠胸腺淋巴细胞增殖

目的:观察反义c-myc寡核苷酸对大鼠胸腺淋巴细胞增殖的抑制作用。方法:Ficoll密度梯度离心法分离大鼠胸腺淋巴细胞。利用Iipofectin将正义、反义及错配c-myc寡核苷酸导入大鼠胸腺淋巴细胞,-TdR掺入法及MTS法检测淋巴细胞增殖,RT-PCR检测c-mycmRNA的表达。结果:反义c-myc寡核苷酸可抑制大鼠胸腺淋巴细胞的增殖,但此抑制作用无浓度依赖性,反义c-myc寡核苷酸可降低胸腺淋巴细胞c-mycmRNA的表达。结论:反义c-myc寡核苷酸可抑制大鼠胸腺淋巴细胞的增殖。     

Lectin-binding patterns of small lymphocytes in bone marrow,thymus and spleen: demonstration of lymphocyte subsets by quantitative radioautography

Cells from mouse bone marrow, thymus and spleen were exposed to ¹²⁵I-labeled concanavalin A (Con A), Lens culinaris lectin (LCL), soybean agglutinin (SBA), Helix pomatia agglutinin (HPA), phytohemagglutinin-P (PHA-P), peanut agglutinin (PNA), or wheat germ agglutinin (WGA) in a range of concentrations and examined radioautographically. Small lymphocytes in the three organs differed in the minimal concentration of each lectin which gave detectable surface labeling, while at optimal lectin concentrations, their labeling intensity profiles differed markedly. Inhibition by sugars demonstrated the labeling specificity. Major populations of bone marrow small lymphocytes bound WGA strongly, while Con A, SBA, HPA, PHA-P and LCL were bound only weakly, and PNA binding was lacking. Most thymus cells bound Con A, SBA, HPA, PHA-P and PNA strongly, WGA and LCL weakly. Subsets of bone marrow and thymus small lymphocytes differed from the major populations in their lectin-binding intensities. Spleen small lymphocytes were heterogeneous in the binding of each lectin. However, a major population bound LCL exceptionally strongly, while few cells bound PNA. Using a panel of lectins under standardized conditions, these studies show distinctive lectin-binding patterns for small lymphocytes in the bone marrow, thymus and spleen, respectively. Major and minor cell populations are distinguishable in each organ, providing an approach to discriminating lymphocyte lineages, subtypes and differentiation stages.     

Transplantation of retrovirally transduced bone marrow prevents autoimmune disease in aged mice by peripheral tolerance mechanisms

Transplantation of bone marrow (BM) engineered to express self-antigen has been shown to protect 100% of young mice from myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE), with thymic clonal deletion as a tolerance mechanism. Here, we asked whether aged mice can also be tolerised following transplantation with self-antigen-engineered BM and whether castration-induced thymus regrowth can enhance this outcomes. Then, 50% of aged mice were protected from EAE regardless of castration-induced thymus regrowth. EAE-free and diseased mice demonstrated MOG-specific lymphocyte proliferation and antibody production regardless of castration-induced thymus regrowth, consistent with lack of intrathymic deletion of self-antigen-reactive T cells. Although low chimerism levels ( < 4%) were observed, EAE-free mice showed significantly higher chimerism levels in lymphocytes in peripheral lymphoid organs compared with thymus. CD4⁺CD25⁺ regulatory T cells were elevated in lymph nodes of EAE-free mice. We conclude that transplantation of self-antigen expressing BM protects 50% of aged mice and castration-induced thymic regrowth had no effect on outcomes. Peripheral tolerance mechanisms are implicated since protection is associated with higher chimerism levels in peripheral T and B lymphocytes and with elevated regulatory T cells.     

Antigen-binding small lymphocytes in the guinea-pig: I. The immunological response to human thyroglobulin

The time course of the relative distribution of small lymphocytes binding ¹²⁵I-labelled human thyroglobulin (HTg) in cell suspensions from the peripheral blood and various lymphoid organs was studied in guinea-pigs at progressive intervals up to 28 days after immunization with an emulsion of HTg and BCG in Freund's incomplete adjuvant (FIA). Small lymphocytes binding ¹²⁵I-labelled HTg were first detected in peripheral blood, popliteal (draining) lymph node, spleen and bone marrow preparations on the 10th day, and in mesenteric (distant) lymph node and thymus preparations on the 14th day after primary immunization. In general, the percentage of these cells increased progressively thereafter until the end of the period of study. Blocking experiments with unlabelled antigens indicated that the binding of ¹²⁵I-labelled HTg by small lymphocytes was specific. An anti-HTg antibody cytophilic for guinea-pig small lymphocytes was demonstrated by the passive transfer of antigen-binding capacity to lymphocytes of unimmunized animals with hyperimmune guinea-pig serum. It is proposed that, in these experiments, anti-HTg cytophilic antibody was bound first to small lymphocytes in the tissues participating actively in the immune response (popliteal node, spleen and bone marrow) before spilling over into the general circulation to coat lymphocytes at other sites (mesenteric node and thymus).     

Mode of action of anti-lymphocyte globulin: II. Changes in the lymphoid cell population in rats treated with anti-lymphocyte globulin

Lymphopenia in rats which had been made tolerant to normal rabbit immunoglobulin G(IgG) was induced by the administration of rabbit anti-rat immunoglobulin G(IgG). The rats were injected with tritiated thymidine ([³H] thymidine) and the labelling pattern in lymphoid tissues was studied. The thymus weight decreased with continued lymphopenia and this could be explained by the release of small lymphocytes into the circulation. Lymphopoiesis in the thymus and spleen was not inhibited by anti-lymphocyte globulin. Plasmacytosis was noted in the lymph nodes. These findings support the idea that anti-lymphocyte globulin acts mainly on peripheral lymphocytes and suppresses the immune function mediated by these cells.     

Effect of embryo irradiation on development of the thymus and formation of the T-lymphocyte population

Irradiation of pregnant mice causes destruction of the embryonal thymus and delays its colonization with lymphocytes, T-helper maturation, and elimination of T-lymphocyte precursors. After birth splenic colonization with lymphocytes, particularly with T helpers and T suppressors, is decresed. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 4, pp. 416–421, April, 1994     

Long-term immunoglobulin G production by transplanted thymus cells

Two sublines of CBA/H mice congenic for the Igl allotype locus were used to study donor-allotype IgG_2a concentrations in the serum of mice injected intravenously with thymus cells. High concentrations (up to several mg/ml) were found in x-irradiated recipients(exposed to 650 rad, or to 900 rad with a restorative injection of fetal liver cells). The highest concentrations were seen 1–2 months after injection, but detectable quantities were still present in most individuals after 377 days. No donor-allotype Ig was detected in non-irradiated recipients. Cell for cell, lymph node cells were about as efficient as thymus cells at transferring IgG production. Although pluripotent hema- topoietic stem cells were found in the thymus, their concentration (about 10^?8) was too low to account for the results. It is suggested that the thymus contains B lymphocytes, or their precursors, with considerably greater powers of self-maintenance and expansion than are possessed, on average, by the B lymphocytes in lymph nodes.     

Lymphocyte Plasma Membranes III Carbohydrate Containing Antigens of Human Lymphocytes Bound by Antilymphocyte Sera

Lymphocytes were labeled by the sequential application of periodate ³H-borohydride. The labeled viable cells were solubilized in 0.5% NP₄₀ and the resulting soluble material was precipitated with different rabbit anti-human lymphocyte sera (ALS). The ALS specifically bound isotope which was characterized by electrophoresis on polyacrylamide gels in SDS. Three major components were visualized, a high molecular weight (MW) component(s) (MW ～100-200,000), a component of MW ～48,000 and very low MW material. Differences were described in the electropherograms of lymphocytes from human thymus, tonsil, blood and cultured lines. Differences were also found in the antigenic reactivity of ALS prepared against thymus and ALS prepared against cultured human lymphocytes.     

Effect of thymus factor on human precursor T lymphocytes

A pig thymus factor is shown to transform in vitro human immature lymphoid cells (from cord blood, bone marrow and foetal tissue) into mature T lymphocytes forming spontaneous rosettes with sheep erythrocytes. No effect was observed on normal mature lymphocytes (T or B cells), suggesting a selective activity of the thymus factor for precursor T lymphocytes.

When lymphocytes from various patients were treated with the thymus factor, the most pronounced effect was found on cells from T cell-deficient patients. This finding suggests that these patients were lacking such a humoral thymus factor and were not genuinely deficient in their lymphocytes. Our results indicate a potential diagnostic value of the thymus factor, especially in the analysis of immunodeficiency diseases.

     

Thymus dependence of θ-bearing cells in the peripheral lymphoid tissues of mice

In mice thymectomized as newborns, thymectomized as adults and irradiated, and in nude mice with congenital absence of the thymus, there is a marked reduction in the number of θ-bearing lymphocytes in the lymph nodes and spleen. This suggests that θ is present on those lymphocytes which are thymus-derived. Using ⁵¹Cr and dye exclusion cytotoxic testing, approximately 65–85 per cent of lymph node and thoracic duct lymphocytes and 30–50 per cent of spleen lymphocytes were found to have θ on their surface.     

Autoradiographic study on the distribution of thymus-derived and thymus-independent lymphocytes in the spleen of Xenopus laevis

Non-thymectomized and early-thymectomized Xenopus laevis were injected with ³H-thymidine, and labelled lymphocytes from thymus, spleen, and peripheral blood were transferred to histocompatible recipients to study their distribution by autoradiography. An extremely high proportion of labelled thymocytes was localized in the splenic red pulp of both non-thymectomized and thymectomized recipients after transfer. Labelled splenic lymphocytes were localized in a significantly higher density in the splenic white- than red pulp, particularly 24 hr after cell transfer. This preference of labelled lymphocytes in the white pulp was more evident when early-thymectomized toads were used as lymphocyte donors. These results strongly suggest that in Xenopus, thymus-independent lymphocytes preferentially localize in the splenic white pulp, and thymus-derived lymphocytes possibly in the red pulp.     

The role of hematogenous and intrinsic precursor cells in lymphocyte production in murine bone marrow and thymus

It is well recognized that the bone marrow contains cells that can repopulate a depleted thymus as well as cells that can be induced to express phenotypic markers characteristic of T cells. It is not known, however, to what extent thymocytopoiesis in the normal thymus relies on immigrant, bone marrow-derived cells, nor whether some T cell precursors have entered the bone marrow from the circulation. We used the parabiotic system to test whether thymocytopoiesis relies on progenitors intrinsic to the thymus or on cells that enter the organ from the circulation. In the same system, we have also investigated whether Thy-1^? bone marrow lymphocytes that respond to phytohemagglutinin (PHA) by proliferation and Thy-1 expression are produced by my-elogenous or hematogenous progenitors. Syngeneic CBA/HT6 and CBA/CaJ mice were joined in parabiotic union at 4–6 weeks of age. Cross circulation between the two partners was verified by the equilibration of Evans' blue dye injected into one partner and by the equilibration of PHA-responsive T cells in the spleen of the parabionts. Chromosome spreads were prepared from the PHA-stimulated T cell-depleted bone marrow and from spontaneously proliferating thymocytes as well as from thymocytes stimulated by PHA or Concanavalin A (Con A). The exchange of spleen colony-forming units (CFU-S) in the femoral marrow was assessed by karyotyping individual spleen colonies. Regardless of the length of parabiotic union, ranging from 4 to 20 weeks, Thy-1^?, PHA-responsive bone marrow lymphocytes remained predominantly of the host type with only 3% being derived from the opposite partner. The same held true for CFU-S in the femur; only around 5% of this cell population were of the nonhost type. Thus, although some Thy-1^?, PHA-responsive lymphocytes in the bone marrow may be derived from hematogenous stem cells, the majority of them are generated by precursors resident in the bone marrow. Likewise, regardless of the length of parabiotic union, at least 95% of spontaneously proliferating cells in the thymus of each partner possessed the karyotype of the host, and this held true also for PHA- or Con A-stimulated thymocytes, indicating that the small population of spontaneously proliferating immigrant cells cannot account for the production of the large number of postmitotic (mitogen-responsive) thymocytes. Our findings, therefore, demonstrate a high degree of self-maintenance for Thy-1^?, PHA-reponsive lymphocytes in the bone marrow and also for intrathymic T cell precursors. In the unperturbed, postnatal thymus, thymoctye production does not rely on cell input from the circulation; the vast majority of thymoctyes are generated by an intrathymic precursor pool that is independent of immigrant myelogenous T cell precursors.     

Stress-induced galectin-1 influences immune tolerance in the spleen and thymus by modulating CD45 immunoreactive lymphocytes

Galectin-1 (Gal-1) is differentially expressed in normal and pathological tissues and regulates immune cell homeostasis. Restraint stress increases serum Gal-1 in rats. However, the function of stress-induced Gal-1 in serum is unknown. We determined if stress-induced Gal-1 in serum accumulates in immunocompetent organs as protection from physiological and/or psychological stress. Western blotting showed that the intensity of Gal-1 bands in stressed groups was significantly higher than that in controls. RT–PCR analysis indicated that the Gal-1 mRNA level did not increase after restraint stress. The numbers of Gal-1 immunoreactive cells in the splenic periarterial lymphatic sheath (PLS) and the thymus medulla of the stressed group were increased compared with those in controls. Furthermore, stress-induced Gal-1 immunoreactive cells corresponded to CD45 immunoreactive lymphocytes (CD45⁺) in the PLS of the spleen and the medulla of the thymus. Thus, stress-induced Gal-1 immediately accumulates in the spleen and thymus, and may modulate the immune response through apoptosis by binding to CD45⁺ lymphocytes in immune organs following physiological and/or psychological stress.     

Changes in Various Measures of Immune Status in Mice Subject to Chronic Social Conflict

Levels of the major regulatory subpopulations of lymphocytes in the thymus and spleen and blood lymphocyte dehydrogenase levels were measured in male mice with aggressive and submissive patterns of behavior formed over 10 or 20 aggressive confrontations leading to repeated experience of victory or defeat. The results showed that repeated experience of social confrontation non-specifically increased the proportion of segmented neutrophils and lactate dehydrogenase activity in both participants in aggressive encounters, and decreased the numbers of CD4⁺ and CD8⁺ T-lymphocytes in the spleen. Succinate dehydrogenase specifically decreased in the lymphocytes of aggressive mice and increased in the lymphocytes of submissive mice. The proportion of CD4⁺ T-lymphocytes in victims' thymuses also decreased. Changes in metabolic measures and percentage ratios of lymphocyte contents were dynamic and depended on the duration of confrontational interactions.     

Circadian Dynamics of Cell Composition of the Thymus and Lymph Nodes in Mice Normally,under Conditions of Permanent Illumination,and after Melatonin Injection

The effect of melatonin on disturbed circadian variations in the lymphocyte subpopulation composition of the thymus and inguinal lymph nodes was studied in CBA mice exposed to constant illumination for 14 days. The desynchronizing effect of permanent illumination on the thymus consisted in disappearance of circadian variations in the total number of thymocytes, absolute count of thymocytes, absolute counts of CD8⁺ and CD4⁺ cells, and in inversion of changes in the absolute counts of CD4⁺8⁺ cells from 15.00 to 20.00. In lymph nodes circadian variations in the percentage of CD4⁺ lymphocytes disappeared, while absolute counts of CD4⁺8⁺ and CD8⁺ cells changed from 15.00 to 20.00. Melatonin restored circadian dynamics of some parameters mainly in the thymus. __________ Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 140, No. 8, pp. 181–185, August, 2005     

Specific antisera against recirculating and non-recirculating lymphocytes in the rat

Heterologous anti-lymphocyte sera were prepared by injecting suspensions of recirculating or non-recirculating lymphocytes into rabbits. Recirculating lymphocytes were obtained from a thoracic duct fistula, and non-recirculating lymphocytes were obtained from the blood of rats in which thoracic duct lymph had been drained away for 3 days. The cytotoxic activity of the sera was assayed by measuring the isotope release from target cells labelled with ⁵¹Cr. Antibodies specific for recirculating or non-recirculating lymphocytes could be demonstrated with the aid of cell adsorption techniques.

Cell-specific sera were used to estimate the proportion of recirculating and non-recirculating lymphocytes in lymphocyte suspensions obtained from thymus lymph nodes, blood and bone marrow. All thymocytes and most of the lymph node lymphocytes appeared to have antigenic properties in common with recirculating lymphocytes, whereas about 20% of the blood lymphocytes and most of the bone marrow lymphocytes belonged to the non-recirculating lymphocyte antigenic type.

     

Cytological profile of the thymus of mice with increased resistance to P3-X63-Ag8.653-MOPC plasmocytoma after stress

Pronounced stimulation of antigen-independent differentiation of T lymphocytes is found. Physical loads and immobilization stress are shown to considerably augment both the immigration of T lymphocyte precursors to the thymus and the emigration of differentiated lymphocytes, as well as to affect the rate of cell differentiation. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 5, pp. 454–456, May, 1994 Presented by N. K. Permyakov, Member of the Russian Academy of Medical Sciences     

Thymus‐resident memory CD8+ T cells mediate local immunity

The thymus is a primary lymphoid organ responsible for production and selection of T cells. Nonetheless, mature T cells and in particular activated T cells can reenter the thymus. Here, we identified memory CD8⁺ T cells specific for lymphocytic choriomeningitis virus or vaccinia virus in the thymus of mice long‐time after the infection. CD8⁺ T cells were mainly located in the thymic medulla, but also in the cortical areas. Interestingly, virus‐specific memory CD8⁺ T cells in the thymus expressed the cell surface markers CD69 and CD103 that are characteristic of tissue‐resident memory T cells in a time‐dependent manner. Kinetic analyses and selective depletion of peripheral CD8⁺ T cells by antibodies further revealed that thymic virus‐specific memory CD8⁺ T cells did not belong to the circulating pool of lymphocytes. Finally, we demonstrate that these thymus‐resident virus‐specific memory CD8⁺ T cells efficiently mounted a secondary proliferative response, exhibited immediate effector functions and were able to protect the thymus from lymphocytic choriomeningitis virus reinfection. In conclusion, the present study not only describes for the first time virus‐specific memory CD8⁺ T cells with characteristics of tissue‐resident memory T (T_RM) cells in a primary lymphoid organ but also extends our knowledge about local T‐cell immunity in the thymus.     

Toxic effects of mercuric sulfide on immune organs in mice

Mercuric sulfide (HgS) is a major component of cinnabar, which has been used as a sedative drug in China for more than 2000 years. Because its toxicological effects are still unclear, we attempted to verify the toxic effects of HgS, focused on liver and immune organs such as the spleen and thymus. Male ICR mice were administered HgS (0.02, 0.2, 2.0?g/kg/day) by gavage for 4 weeks. During the administration period, HgS-treated mice did not reveal overt signs of clinical toxicity. HgS had no significant effect on body weight, food consumption, water consumption, and organ weights. In spite of its known insolubility, HgS was absorbed by the gastrointestinal tract and accumulated in the liver, spleen and thymus in a dose-dependent manner. In the biochemical and histological examination, HgS did not cause hepatotoxicity. However, HgS significantly increased both CD8⁺ T lymphocytes and CD4⁺CD8⁺ lymphocyte populations in the spleen without changing in the thymus. In the histological evaluation, HgS induced enlargement with marked hyperplasia and increase of lymphoid follicles in the spleen. In addition, HgS induced the gene expression of pro-inflammatory cytokines in the spleen and thymus. Our results suggest that insoluble HgS was absorbed by the gastrointestinal tract, accumulated in the spleen and thymus, and thus could affect immune systems.