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The effects of crude thymus extract on the immune response and protection against challenge with virulent infectious bursal disease virus (IBDV) were studied in one-day-old chick. Oral administration of thymus extract (1 ml/kg) markedly and significantly increased the total protein, albumin, globulin, Tri-iodothyronine (T3), Thyroxine (T4) and the body weight gain in one-day-old chick. In addition, it increased the total lymphocytic count over four weeks after administration. Although vaccination also increased total protein, globulin, T4 and the total lymphocytic count but it significantly decreased the body weight gain of the chick and administration of thymus extract, before, during or after vaccination markedly improved the vaccination effectiveness with significant elevation of the globulin level and body weight gain of the chick. It also prevented the decrease in the relative weights of bursa, spleen and thyroid gland which commonly prevailed during vaccination. Chicken administered thymus extract and vaccinated with infectious bursal disease (IBD) vaccine showed 100% protection against challenge with IBDV. Meanwhile the vaccinated non-thymus treated group exhibited 80% protection against IBDV challenge. These results indicate a potentiating effect of thymus extract on the immune system in baby chick. These findings are supported by ELISA results that showed a marked increase in antibody titers in thymus treated groups. Additionally, microscopical examination of the bursa and the existent lymphoid hyperplasia in thymus treated groups but not vaccinated group support our findings.
Cell proliferation in the murine thymus was studied in vivo under normal conditions and from 0 to 24 hr after a single injection of a water-soluble extract from mouse thymus, mouse spleen, and mouse skin. The thymus extract reduced during the first 24 hr the mitiotic activity 40%; the spleen extract had a weaker inhibitory effect. The skin extract had no such effect. The thymus extract and spleen extract inhibited the flux of cells into the S phase 0-8 hr after the injection of the extract. Initial labelling index was also reduced in this period. Eight hours after injection of the thymus or spleen extracts the inhibited cells initiated DNA synthesis. The rate of progression of blast cells through the cell cycle was normal 24 hr after the injection of the extracts. It was deduced from the analysis that the thymus extract inhibits processes triggering G0/G1 cells into DNA synthesis, the inhibition of G2 efflux being of minor importance. Finally a model for the regulation of proliferating thymic blast cells and the emigration of small lymphocytes from the thymus is proposed.
The semipurified calf thymus extract, TFX, produced since 1973 by the Polish Pharmaceutical Industry (POLFA) has been found to exert biological activities meeting criteria for thymic hormones. During the last 15 yr TFX has been evaluated independently by several Polish medical centers in over 1000 patients with symptomatically different but pathogenically similar human diseases, including primary immunodeficient states, bone marrow failure, autoimmune disorders, chronic skin diseases, recurrent viral and bacterial infectious diseases and some oncological disorders. Long term immunotherapy with TFX--expressing the pro-host approach--resulted, in the majority of the observed patients, in amelioration of symptoms and signs of the disease and in parallel normalization of disturbed immune parameters. It is suggested that IFX (and perhaps other thymic hormones) would support, modify and enrich future treatment protocols, especially in patients with immunodeficiency-related or chronic immune-mediated diseases.
Spontaneously hypertensive rats (SHR) that develop hypertension and arterial lesions resembling human periarteritis nodosa were found to possess a selective depression of T cell functions with an appearance of natural thymocytotoxic autoantibody (NTA). The relationship between T cell depression and hypertension in these animals was investigated. The immune responsiveness of T cell-depressed SHR was completely recovered by histocompatible thymus grafts and was partially restored by histoincompatible allogeneic or xenogeneic thymus grafts or by injection of thymus extracts. Transplantation of compatible thymus tissues into neonatal SHR produced long-lasting recovery of immune functions. When complete immunologic restoration was achieved, significant suppression of high blood pressure was obtained. The SHR that showed high blood pressure were always accompanied with high NTA titers and arterial lesions. Thymus grafts or thymus extracts significantly decreased the titers of NTA. The development and dissemination of arterial lesions, which may cause increased blood flow resistance, were completely prevented by compatible thymus grafts into neonatal SHR. These results suggest that thymus grafts and thymus extracts may suppress the development of hypertension by preventing or curing the periarteritis nodosa in SHR.
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The administration of thymus extract (TFX) has been performed in 35 patients suffering from malignancies of the alimentary tract. TFX, being a calf thymuses extract prepared by Jelenia Góra Drug Producers "Polfa" was given in the dose of 0.5 mg in 3 or 7-day intervals during several months. The immunological condition of patients was checked by many tests: E-rosettes, DLT (direct lymphocytotoxicity test) determination of absolute number of peripheral blood lymphocytes and skin tests (RT-23, PHA and TFX). Our observations revealed that TFX is biologically active also in humans, increases cell-mediated immunity and may restore the immune capability of patients operated due to malignancies of the alimentary tract.
In our investigations the qualification of the substances 2-cyanoethyl urea, thymus extract and lithium carbonate was tested for a potential reducing or shortening of the leukocyte-depression in rats after whole-body irradiation. Intravenous applications of 2-cyanoethyl urea and intramuscular injections of thymus extract showed no effect in Wistar rats not only in increase of leukocyte number of peripheral blood, but also in variation of leukocyte portion in differential blood-count. Leukocytes depression appearing in consequence of whole-body irradiation was independent of cyanoethyl urea applications and of thymus extract, too. Lithium carbonate shows a significant increase of leukocytes in peripheral blood in dependence of dosage and frequency of applications. After whole-body irradiation with 7 Gy under lithium therapy, it was shown that on day 6 after irradiation leukocyte number was significantly higher than in controls. Radiogenic leukopenia phase was reduced significantly by lithium.
The effects of two calf thymus extracts (fraction III and Tp1) on the haematic levels of cholesterol and glucose in the rat on a fat diet have been compared. The fraction III carries out a very marked decrease of cholesterolemia without changes in the levels of glycemia. On the contrary the Tp1 determines only a moderate decrease of cholesterolemia but a very marked decrease of glycemia. Thherefore these results seem both to confirm the differences between the two thymus extracts and the metabolic actions of thymus.
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The main goal of this study was to evaluate the possible influence of thymus extracts on the chemotaxis of PMN isolated from diabetic patients. The analyzed group consisted of fifty patients with insulin-dependent diabetes mellitus (IDD), and twenty healthy adults were taken as controls. The results showed, that PMN isolated from patients with IDD manifested the impaired chemotaxis toward zymosan-activated plasma (ZAP), plasma incubated with cellophane and supernate from E. coli culture. Both thymus extracts did not change the directed migration toward control plasma and toward ZAP. THYMEX-L did improve the migration of diabetic PMN toward plasma incubated with cellophane, whereas TFX-THYMOMODULIN ameliorated the impaired chemotaxis toward supernate from E. coli culture. Both thymus extracts can attract PMN obtained from healthy donors, but not the cells isolated from diabetic patients.
One of the fractions of the thymus extract of a calf obtained by the authors restored the synthesis of antibodies to sheep erythrocytes in neonatally thymectomized mice and rats. Fractions isolated anologously from the tonsils and the lymph nodes failed to influence the antibody genesis. The data obtained are in favor of the endocrine function of the thymus of significance in the establishment and regulation of the immunological reactivity.
In the present in vitro study, the influence of proteolytic as well as untreated spleen and thymus extracts and, as a comparison, of biologically active peptides tuftsin and thymopentin on the phagocytic activities of human polymorphonuclear leukocytes was investigated. At a chosen concentration of 200 micrograms/ml, all products studied exhibited a significant stimulation of polymorphonuclear leukocyte activity, when lucigenin-amplified chemiluminescence was measured. This effect was considerably enhanced with tuftsin, thymopentin and spleen extract, compared to the thymus preparations. No difference in chemiluminescence was obvious between hydrolyzed and untreated thymus extracts. In parallel experiments, phagocytosis of opsonized zymosan was investigated by light microscopy. Using identical substrate concentrations, only spleen extract showed significant stimulation. This observation indicates that the investigated polymorphonuclear leukocyte activities may be caused by substrate-specific mechanism on the cellular level.
The human promyelocytic cell line HL-60 can be differentiated with retinoic acid (RA) along the granulocytic pathway. Numerous studies have identified many synergistic combinations of RA with cytostatics, cytokines and other inducers. A combination of RA with the crude thymus extract Thymex-L increased differentiation of HL-60 cells as confirmed by two functional assays and morphology, whereas the extract itself did not show any effect. The functional markers phagocytosis-associated chemiluminescence and nitroblue tetrazolium reduction were more enhanced (up to 4-fold with 1000 micrograms/ml Thymex-L) than morphology. The effect was found over a wide RA concentration range (10(-11) - 10(-6) M) and was dependent on extract concentration. The half-maximal induction of both functional markers was reached at 400 micrograms/ml. To achieve the same effect with the combination in comparison with RA alone, an RA dose reduction of about 100-fold was estimated. The effect was also seen when the cells were pretreated with the thymus extract for two days. The enhancement of RA action by Thymex-L was not correlated with an increase of extracellular or intracellular RA concentration. The active compound in Thymex-L is heat stable and bigger than 5 kDa as confirmed by gelfiltration. The defined thymus peptides thymosin alpha 1, prothymosin alpha 1 and thymopentin were unable to synergistically enhance HL-60 differentiation. These data suggest that the treatment with a thymus extract can increase the sensitivity of HL-60 cells for RA. This may have clinical implications.
The influence of thymus extract (TFX) on phagocytosis and bactericidal capacity of polymorphonuclear neutrophils (PMN) from patient with insulin-dependent diabetes was studied. In previous observations PMN from these patients revealed the serum-related defect of bacterial killing. The preincubation of cells with standard dose of TFX significantly increased ingestion rate and recovered the bactericidal capacity to normal values. The augmentation of bactericidal capacity due to preincubation with TFX appeared to be dose-dependent and not related to other blood cells participation. The increase of bacterial killing was also evident, when TFX was applied after phagosome formation. The presented studies indicate that, among numerous peptides, thymus extracts contain those exerting their hormone-like activity on polymorphonuclear neutrophils. The observations may be of clinical importance.
Investigations were carried out on the non-specific cell-mediated response in mice with transplantable tumours: LLC in mice C57Bl and F1(C57Bl X C3H), and SAL-l tumour in Balb/c mice. The malignant cells were implanted subcutaneously for observation of changes in the non-specific cell-mediated response at the time of the local growth of the tumour, and injections into the vein or into the foot-pad were made for studying the non-specific cell-mediated response at the time of tumour dissemination. In each series of the experiments the animals received an extract of calf thymus--the preparation TFX-Polfa. The control groups had the tumour cells implanted or injected but were not given TFX. For determining the non-specific cell-mediated response the animals were immunized with picryl chloride. In both experimental models, that is with subcutaneous implantation and with injections intravenously or into the foot-pad a decrease of the non-specific cell-mediated response was observed progressing gradually with extension of the tumours. Long-term administration of TFX in doses of 0.1 mg per mouse prevented the decrease of the non-specific cell-mediated response in the first place in mice with subcutaneous implantations. In mice with malignant cells injected intravenously or into the foot-pad TFX administration had no evident effect on the value of the test. This observation suggests that TFX prevents the development of a secondary immune deficit in mice with subcutaneous transplanted tumours--that is mainly at the time of local growth of the tumour, but is of little use in the phase of tumour dissemination.