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PubMed1981

[Restoration of immune functions in T-cell depressed spontaneously hypertensive rats (SHR) by injection of neurotropin (author's transl)].

A strain of spontaneously hypertensive rats (SHR) showed a progressive decline in T-cell functions with aging. In order to restore the depressed immune functions, the effect of immunopotentiators such as Neurotropin, PS-K or thymus extract on immune responses of SHR was studied. The results presented here demonstrated that injection of Neurotropin completely restored the T-cell functions in SHR as detected by a rosette forming test, a plaque forming assay and blastogenesis. Administration of thymus extract also restored the immune functions except helper T-cell activity. However, administration of PS-K increased only numbers of rosetting cells in the thymus of SHR. Biological significance of Neurotropin as immunopotentiators was discussed.

Adjuvants, Immunologic↗
PubMed2006

Rapid actin monomer-insensitive depolymerization of Listeria actin comet tails by cofilin, coronin, and Aip1.

Actin filaments in cells depolymerize rapidly despite the presence of high concentrations of polymerizable G actin. Cofilin is recognized as a key regulator that promotes actin depolymerization. In this study, we show that although pure cofilin can disassemble Listeria monocytogenes actin comet tails, it cannot efficiently disassemble comet tails in the presence of polymerizable actin. Thymus extracts also rapidly disassemble comet tails, and this reaction is more efficient than pure cofilin when normalized to cofilin concentration. By biochemical fractionation, we identify Aip1 and coronin as two proteins present in thymus extract that facilitate the cofilin-mediated disassembly of Listeria comet tails. Together, coronin and Aip1 lower the amount of cofilin required to disassemble the comet tail and permit even low concentrations of cofilin to depolymerize actin in the presence of polymerizable G actin. The cooperative activities of cofilin, coronin, and Aip1 should provide a biochemical basis for understanding how actin filaments can grow in some places in the cell while shrinking in others.

Actin Cytoskeleton↗
PubMed1984

Multiplicity of antibodies in myositis sera.

Serologic studies on 114 patients with polymyositis and dermatomyositis revealed that 89% had either a precipitating antibody to antigens in calf thymus extract or a positive immunofluorescent reaction on HEp-2 cells, a human tissue culture line. Previously, the greatest proportion of polymyositis sera demonstrating positive serologic results (i.e., the proportion of patients' sera forming precipitates with calf thymus extract) was reported to be 60%. Use of the HEp-2 cell as immunofluorescent substrate enabled the detection of antibody in 89 (78%) of the sera, providing the additional probe which demonstrated specific antibody. Nuclear, cytoplasmic, and nucleolar staining are the most common patterns of immunofluorescence. The immunofluorescent patterns and individual precipitin reactions are related to each other and to the clinical syndromes in which they appear.

Animals↗
PubMed1989

The role of counterimmunoelectrophoresis in the identification of antibodies to extractable nuclear antigens.

Antibodies to saline-extractable nuclear antigens are hallmarks of autoimmune diseases including systemic lupus erythematosus (SLE), mixed connective tissue disease, progressive systemic sclerosis and Sjogren's syndrome. In our laboratory, we use counterimmunoelectrophoresis as a screening test and immunodiffusion as a confirmatory test to identify these autoantibodies. This study examines the drawbacks of such an approach. Though 17 out of 19 sera that formed ribonuclease sensitive lines with rabbit thymus extract on counterimmunoelectrophoresis were confirmed to have anti-RNP by immunodiffusion, sera of several different autoantibody specificities were seen to form ribonuclease resistant precipitin lines with the thymus extract on counterimmunoelectrophoresis. Having screened sera to have autoantibodies by counterimmunoelectrophoresis, the identity of some of these autoantibodies were not confirmed because of the poor sensitivity of immunodiffusion or because inappropriate controls had been used for the confirmatory immunodiffusion test. To check these drawbacks and to obviate the need for a confirmatory test, a modification of the current approach is suggested.

Animals↗
PubMed1982

The in vivo effect of a thymic factor (thymostimulin) on immunologic parameters of patients with untreated Hodgkin's disease.

The in vivo effect of a calf thymus extract (thymostimulin, TS) on the E-rosetting capacity, PHA blastogenic response, serum migration inhibitory activity (LIF) and skin reactivity to recall antigens was evaluated in 19 untreated patients with Hodgkin's disease. In patients the mean percentage of peripheral blood lymphocytes forming E-rosettes increased from 47 to 55.7% (P less than or equal to 0.001; normal: 58.9). The mean PHA stimulation index rose with all three concentrations tested but did not reach normal values. Serum LIF was positive in only one patient prior to treatment with a mean LIF for all patients of 0.75 (P less than or equal to 0.005). Skin tests were positive in ten patients (52.6%) prior to therapy and 18 patients following therapy (94.7%; P less than or equal to 0.05). Thymostimulin, in vivo, appears to return immunologic competency to a population of untreated patients with Hodgkin's disease.

Adult↗
PubMed1975

Thymus-repopulating capacity of cells that can be induced to differentiate to T cells in vitro.

It was established previously that committed precursors of T cells, which reside in bone marrow and spleen and lack T cell surface differentiation antigens, can be induced by thymopoietin and certain other agents to differentiate rapidly in vitro into T cells bearing typical surface antigens, including Thy-1 and TL (Komuro-Boyse assay). To relate this differentiative step observed in vitro to physiologic events in vivo, a system was devised to trace the migration of precursor cells to the thymus, and their maturation to T cells. Lethally irradiated mice of a TL- strain received spleen cells from TL+ hybrids i.v., and the TL+ population of the thymus was enumerated 13 to 20 days later. Donor TL+ cells first became detectable at 13 days and increased thereafter. Preliminary tests showed that cells capable of migrating to the thymus have a similar density to the cells that are inducible in the Komuro-Boyse assay, this being lower than that of mature of T cells. The thymus-repopulating properties of the donor spleen population were not affected by: 1) pre-treatment in vitro with thymus extract or thymopoietin, which initiates differentiation of T cells precursors, nor b) pre-treatment with anti Thy-1 serum plus complement, which eliminates differentiated T cells. But pre-treatment a) and b) applied in sequence markedly reduced the capacity of spleen cells to repopulate the thymus. These results can be interpreted as follows: induction of Thy-1-TL- precursor cells (pro-thymocyte) in vitro yields Thy-1+TL+ cells (early thymocytes) which have not yet lost their property of repopulating the thymus; therefore, thymus-repopulation was not depleted by treatment a) alone, which induced Thy-1 +TL+ cells, nor by treatment b) alone, which did not affect thymus-repopulation by Thy-1-TL- cells, although treatments a) plus b) did eliminate the newly induced Thy-1+TL+ cells and thus impaired repopulation of the thymus. We conclude that the cell which responds to thymopoietin in the Komuro-Boyse assay by expressing the T cell surface phenotype is the same cell (pro-thymocyte) that normally migrates in vivo from hemopoietic tissues to the thymus and is there induced by thymopoietin to express the phenotype of an early T cell.

Animals↗
PubMed1989

Molecular characterization of the SM and RNP nuclear antigens.

Patients with systemic lupus erythematosus (SLE) often possess antibodies against two nuclear antigens, designated "Sm" and "RNP". The exact relationship between Sm and RNP is not clear; the present study was conducted to define these two different nuclear antigens. Rabbit thymus extracts were used to obtain purified Sm/RNP complex and free Sm antigens by using a combination of 25-60% ammonium sulfate precipitation, DEAE-Sephacel and hydroxylapatite chromatography. By using the separated antigens, sera characterized as anti-Sm, anti-Sm/RNP and anti-RNP could be distinguished by enzyme-linked immunosorbent assay (ELISA). Anti-Sm and/or anti-RNP antibodies were detected in 32 (52%) of 62 sera from patients with SLE. Of these 32, 6 contained anti-Sm only, 10 contained anti-RNP only and 16 had both. When HeLa nuclear extracts were used as antigens by immunoblotting, sera with anti-RNP reacted primarily with 2 polypeptides of 68 and 45 KD; sera with anti-Sm recognized mainly on 2 polypeptides of 26 and 14 KD; sera with anti-Sm/RNP recognized both groups. When purified Sm/RNP complex from rabbit thymus extracts was used as antigen by immunoblotting, sera with anti-RNP reacted with 68 KD protein and putative degradation products of the 68 KD protein. (major: 63 KD, 45 KD, 40 KD; minor: 54-47 KD); sera with anti-Sm recognized 14 KD protein; sera with anti-Sm/RNP reacted with both groups. Although Sm and RNP can exist as a Multimolecular complex, the epitopes recognized by anti-Sm and anti-RNP differ greatly. The Sm determinants reside primarily on proteins of 26 KD and 14 KD, whereas the RNP determinants reside mainly on a protein of 68 KD.

Animals↗
PubMedDate not supplied

Critical reexamination of the thymus immunization model of myasthenia gravis.

Previous studies have described an experimental model of myasthenia gravis (MG) produced by immunizing animals with thymus extracts. In view of the hypothesis that the autoimmune process in MG may be initiated within the thymus itself, we have reexamined this model using presently available methods to evaluate its resemblance to MG. We immunized Lewis rats with extracts of rat thymus in Freund's adjuvant, as originally described by G. Goldstein. Five procedures were used to test for myasthenic characteristics: (1) repetitive nerve stimulation; (2) recording of miniature endplate potentials; (3) assays of anti-ACh receptor antibodies in serum; (4) determination of ACh receptors at neuromuscular junctions by [125I] alpha-bungarotoxin binding; and (5) evaluation of the histology of the thymus gland. Our results showed that the thymus-immunized animals did not demonstrate abnormalities in any of these parameters. We conclude that immunization of rats with thymus extracts, as described, failed to produce a myasthenia-like condition.

Animals↗
PubMed2002

Effects of thymomimetic drugs and zinc supplementation on the cellular immune response in hydrocortisone-suppressed mice.

The studies were carried out on Balb/c mice (5-6 weeks of age) exposed to immunosuppression by a single intraperitoneal dose (125 mg/kg) of hydrocortisone. Prior to hydrocortisone injection the mice were treated with diethyldithiocarbamate (DTC) intra-peritoneally at a dose of 20 mg/kg, five times at 48 h intervals or calf thymus extract (TFX) at a dose of 10 mg/kg, 10 times at 24 h intervals. The two drugs were used per se or in zinc ions interactions, by adding zinc ions (as sulphate salt) to drinking water at a dose of 72 microg/mouse per day. The results obtained in the study show that hydrocortisone injection drastically decreases the number of thymocytes and splenocytes, which is also accompanied by a decreasing weight ratio of the thymus and spleen. The decreasing number of thymic and spleen cells corresponds to a decreasing percentage of CD4+, CD8+ and CD19+ splenocytes and double positive CD4+CD8+ thymocytes. Changes in the number of thymic cells affect their activity, which is expressed in a decreased proliferative response of thymocytes stimulated in vitro with concanavalin A (Con A) and phytohaemagglutinin (PHA). It has also been found that a single hydrocortisone dose decreases interleukin (IL)-1 production by murine intraperitoneal macrophages stimulated in vitro with lipopolysaccharide (LPS) from Escherichia coli. TFX or DTC counteract hydrocortisone-induced immunosuppression, which is expressed in partial normalization of the total number of thymic and spleen cells, accelerated regeneration of the two lymphatic organs, shorter suppressive action of hydrocortisone on the percentage of CD4+, CD8+ splenocytes and double positive (CD4+CD8+) and CD4+ thymocytes. Furthermore, total counteraction against the suppressive action of hydrocortisone to proliferative activity of thymocytes stimulated in vitro with Con A and PHA was observed. TFX administered prior to hydrocortisone injection partially prevented the suppressive action of the drug on IL-1 production by intraperitoneal macrophages, but such an effect was not observed with DTC. The immunorestorative effect of TFX and DTC was augmented by zinc supplementation. The results obtained in the study show that neither TFX nor DTC administration per se and in interaction with zinc supplementation were able to change the suppressive effect of hydrocortisone on the percentage of B splenocytes (CD19+ cells).

Administration, Oral↗
PubMed1985

Monoclonal antibodies to the Sjögren's syndrome associated antigen SS-B (La).

The nuclear autoantigen SS-B (Sjögren's syndrome B antigen) was purified from rabbit thymus extract by immunoaffinity chromatography with human autoantibodies, and used to immunise BALB/c mice for production of monoclonal antibodies. Fusion of spleen cells from an immunised mouse with NS-1 myeloma cells resulted in the isolation of 3 clones secreting anti-SS-B antibody. Subclasses were shown to be IgG2b by immunodiffusion. Specificity of the monoclonal antibodies (MCA) was determined by ELISA and indirect immunofluorescence. By immunoblotting all 3 MCA identified a single 45 K immunoreactive polypeptide in rabbit thymus, identical with the major polypeptide recognised by human sera containing anti-SS-B. Affinity columns prepared from the 3 MCA all bound SS-B from rabbit thymus extract, without binding other nuclear antigens. Immunofluorescence studies on standard substrates showed that SS-B was located predominantly in the nucleoplasm but in cells transformed by EBV or phytohaemagglutinin more prominent nucleolar and cytoplasmic staining was seen.

Antibodies, Monoclonal↗
PubMed1976

Detection of anti-acetylcholine receptor factors in serum and thymus from patients with myasthenia gravis.

Since the blood and thymus of patients with myasthenia gravis may contain inhibitors of neuromuscular transmission that affect acetylcholine receptors of striated muscle, we used denervated rat muscle to test for inhibitors in 43 serums and 18 thymus glands from such patients. Seven per cent of serums inhibited the binding of 125l alpha-bungarotoxin to triton-solubilized receptors; 65 per cent interfered with binding of toxin-labeled receptors to concanavalin-A coupled to Sepharose gel, and 85 per cent formed IgG-receptor complexes detectable by immunoprecipitation. Serum inhibitory activity varied widely among patients with similar clinical manifestations and was not correlated with duration of myasthenia gravis or thymectomy. Among thymus extracts, 44 per cent were inhibitory in the concanavalin-A binding assay, whereas 72 per cent contained anti-receptor IgG. Thus, serums from patients with myasthenia gravis contain more than one anti-receptor factor.

Acetylcholine↗
PubMed1979

Role of thymic hormone (THF) and of a thymic plasma recirculating factor (TPRF) in the modulation of human lymphocyte response to PHA and Con A.

The results presented here point to the possibility that calf thymus extracts contain, in addition to the thymic hormone (THF), a second component: thymic plasma recirculating factor (TPRF). THF, which is involved in the process of T cell maturation and has been characterized as a protein of m.w. 3000 eluted in the void volume of a G-10 Sephadex column (G-10-I), caused an increased level of intracellular cAMP in umbilical cord blood lymphocytes (UCBL). This is in agreement with our previous observation that THF plays a major role in the differentiation of T cells. The second active material, TPRF, also isolated from thymic extract, is of a molecular size below 500 and was eluted in a G-10 Sephadex column at the fourth protein peak; it seems to circulate in the blood. Previously, we had observed in impaired response of UCBL to PHA and Con A stimulation in the presence of dialyzed human plasma (DHP). Our present results indicate that this impaired response is restored exclusively by TPRF. A factor with TPRF-like activity was also isolated from the plasma of normal donors; yet it was not detected in the plasma of thymectomized patients suffering from myasthenia gravis (MG). This suggests that TPRF from plasma is thymus dependent. TPRF does not affect the level of intracellular cAMP in UCBL.

Concanavalin A↗
PubMed1994

Prothymosin alpha and factors from calf thymic cells decrease expression of Thy 1.2 antigen among small thymocytes from C57BL/6 mice.

In this work we studied the effect of Prothymosin alpha (ProT alpha) and other thymic factors on the expression of Thy 1.2 antigen (a T-cell marker) and the activities of adenosine deaminase (ADA, E.C. 3.5.4.4), N-acetyl-beta-D-glucosaminidase (NABG, E.C. 3.2.1.30), beta-glucuronidase (BG, E.C. 3.1.1.1) and serine-esterase (SE, E.C. 3.4.21)., the levels of which change during the T-cell differentiation process among small thymocytes obtained from C57BL/6 mice. Incubation of small thymocytes in the presence of ProT alpha, Thymus Extracts (TE) or supernatants prepared from thymic stromal cells (TSCS) or thymocytes (TS) reduced the proportion of cells killed by anti-Thy 1.2 monoclonal antibodies but did not affect the enzymatic activities studied. This is the first evidence that ProT alpha affects Thy 1.2 expression in vitro.

Acetylglucosaminidase↗
PubMedDate not supplied

Hematologic and histologic experimental investigations on the therapeutic effect of leukotrophin.

The paper aims at evidencing the stimulating effect on hematopoietic stem cells exerted by the thymus extract "Leukotrophin", prepared by Ellem Laboratory, Milan, Italy. Investigation of the hematologic and histologic parameters allowed the follow up of alterations occurring in bone marrow, blood and tissues of the irradiated animals, treated and untreated as compared with the unirradiated and untreated controls. Regeneration was more active in the groups of animals irradiated and treated with Leukotrophin than in the irradiated and untreated controls. A maximal regeneration of the myeloid series, prevalently of the erythrocytic line, was found 9 days after irradiation.

Animals↗