Protective effect of exogenous peroxiredoxin 6 and thymic peptide thymulin on BBB conditions in an experimental model of multiple sclerosis

This study aimed to assess the effects of the immunomodulator thymulin, a thymic peptide with anti-inflammatory effects, and peroxiredoxin 6 (Prdx6), an antioxidant enzyme with dual peroxidase and phospholipase A2 activities, on the blood‒brain barrier (BBB) condition and general health status of animals with relapsing-remitting experimental autoimmune encephalomyelitis (EAE), which is a model of multiple sclerosis in humans. Both thymulin and Prdx6 significantly improved the condition of the BBB, which was impaired by EAE induction, as measured by Evans blue dye accumulation, tight-junction protein loss in brain tissue, and lymphocyte infiltration through the BBB. The effect was associated with significant amelioration of EAE symptoms. Thymulin treatment was accompanied by a decrease in immune cell activation as judged by interleukin-6, -17, and interferon-gamma cytokine levels in serum and NF-kappaB cascade activation in splenocytes of mice with EAE. Prdx6 did not induce significant immunomodulatory effects but abruptly decreased EAE-induced NOX1 and NOX4 gene expression in brain tissue, which may be one of the possible mechanisms of its beneficial effects on BBB conditions and health status. The simultaneous administration of thymulin and Prdx6 resulted in complete symptomatic restoration of mice with EAE. The results demonstrate prospective strategies for multiple sclerosis treatment.

Nanoparticle-based thymulin gene therapy therapeutically reverses key pathology of experimental allergic asthma

Despite long-standing efforts to enhance care for chronic asthma, symptomatic treatments remain the only option to manage this highly prevalent and debilitating disease. We demonstrate that key pathology of allergic asthma can be almost completely resolved in a therapeutic manner by inhaled gene therapy. After the disease was fully and stably established, we treated mice intratracheally with a single dose of thymulin-expressing plasmids delivered via nanoparticles engineered to have a unique ability to penetrate the airway mucus barrier. Twenty days after the treatment, we found that all key pathologic features found in the asthmatic lung, including chronic inflammation, pulmonary fibrosis, and mechanical dysregulation, were normalized. We conducted tissue- and cell-based analyses to confirm that the therapeutic intervention was mediated comprehensively by anti-inflammatory and antifibrotic effects of the therapy. We believe that our findings open a new avenue for clinical development of therapeutically effective gene therapy for chronic asthma.

Modulation of inflammatory response in mice with severe autoimmune disease by thymic peptide thymulin and an inhibitor of NF-kappaB signalling

To investigate some cellular and molecular aspects of the autoimmune response and anti-inflammatory efficiency of potential therapeutic agents in a severe form of experimental autoimmune encephalomyelitis (sEAE), an inhibitor of NF-kappaB signalling, IKK Inhibitor XII, and/or thymic peptide thymulin, were injected intraperitoneally at 1.8 and 0.15mg/kg e.o.d, respectively, to C57BL/6 mice immunized with myelin oligodendrocyte glycoprotein and several adjuvants. The immunization induced high lethality in three weeks. The biphasic cytokine response observed in earlier and delayed phases was attributed to the activity of Th1 and Th17 cells, respectively. Phosphorylation of RelA protein from the NF-kappaB family increased during the earlier phase and decreased in the delayed phase. SAPK/JNK signalling protein and heat shock protein Hsp72 significantly increased in lymphocytes. Both the IKK Inhibitor XII and thymulin reduced disease severity, attenuated immune imbalance, and increased mouse life-span. Co-administration of the agents produced no additive effect. Both the inhibitor and thymulin reduced the Th1 response but not the Th17 response. Therefore, RelA-associated Th1 activation and RelA-independent Th17 activation occurred in sEAE. Thymulin and the inhibitor demonstrate similar patterns of activity, potentially through the RelA pathway inhibition, resulting in a partial therapeutic effect on the animals' health status.

Thymulin inhibits monocrotaline-induced pulmonary hypertension modulating interleukin-6 expression and suppressing p38 pathway

The pathogenesis of pulmonary hypertension (PH) includes an inflammatory response. Thymulin, a zinc-dependent thymic hormone, has important immunobiological effects by inhibiting various proinflammatory cytokines and chemokines. We investigated morphological and hemodynamic effects of thymulin administration in a rat model of monocrotaline (MCT)-induced PH, as well as the pattern of proinflammatory cytokine gene expression and the intracellular pathways involved. Adult Wistar rats received an injection of MCT (60 mg/kg, sc) or an equal volume of saline. One day after, the animals randomly received during 3 wk an injection of saline, vehicle (zinc plus carboxymethyl cellulose), or thymulin (100 ng/kg, sc, daily). At d 23-25, the animals were anesthetized for hemodynamic recordings, whereas heart and lungs were collected for morphometric and molecular analysis. Thymulin prevented morphological, hemodynamic, and inflammatory cardiopulmonary profile characteristic of MCT-induced PH, whereas part of these effects were also observed in MCT-treated animals injected with the thymulin's vehicle containing zinc. The pulmonary thymulin effect was likely mediated through suppression of p38 pathway.

In vivo treatment with a nonapeptide thymic hormone, facteur thymique serique (FTS), ameliorates chronic colitis induced by dextran sulphate sodium in mice

Facteur thymique serique (FTS), a thymic hormone with nonapeptide is involved in T cell differentiation in intestine. Here we investigated the effect of FTS on dextran sulphate sodium (DSS)-induced colitis. BALB/c mice were subcutaneously treated with 1 mug/mouse/day of FTS daily. FTS did not affect the course of acute colitis induced by DSS as assessed by survival rate, clinical activity of diseases, extent of tissue damage of colons. On the other hand, FTS significantly ameliorated chronic colitis induced by multiple cycles of DSS as reflected by lower lethality, weight loss, clinical scores and histological scores. The levels of interferon (IFN)-gamma, interleukin 1(IL-1)-beta, and IL-12p40 in the culture supernatants of lamina propria (LP) cells of colon without any stimulation and IFN-gamma by T cells in the LP T cells under T cell receptor (TCR) triggering were reduced in FTS-treated mice, whereas the levels of IL-10 by LP cells and LPT cells were higher in FTS-treated mice. Thus, FTS may serve to suppress inflammation in DSS-induced chronic colitis accompanied by increased IL-10 production.

Protective Effect of Serum Thymic Factor, FTS, on Cephaloridine-Induced Nephrotoxicity in Rats

Serum thymic factor (FTS), a thymic peptide hormone, has been reported to increase superoxide disumutase (SOD) levels in senescence-accelerated mice. In the present study, we examined the effect of FTS on cephaloridine (CER)-induced nephrotoxicity in vivo and in vitro. We previously reported that CER led to extracellular signal-regulated protein kinase (ERK) activation in the rat kidney. So, we also investigated whether FTS has an effect on ERK activation induced by CER. Treatment of male Sprague-Dawley rats with intravenous CER (1.2 g/kg) for 24 h markedly increased BUN and plasma creatinine levels and urinary excretion of glucose and protein, decreased creatinine clearance and also led to marked pathological changes in the proximal tubules, as revealed by electron micrographs. An increase in phosphorylated ERK (pERK) was detected in the nuclear fraction prepared from the rat kidney cortex 24 h after CER injection. Pretreatment of rats with FTS (50 microg/kg, i.v.) attenuated the CER-induced renal dysfunction and pathological damage. FTS also suppressed CER-induced ERK activation in the kidney. In vitro treatment of the established cell line, LLC-PK1 cells, with FTS significantly ameliorated CER-induced cell injury, as measured by lactate dehydrogenase (LDH) leakage. Our results, taken together with our previous report that MEK inhibitors ameliorated CER-induced renal cell injury and ERK activation induced by CER, suggest that FTS participates in protection from CER-induced nephrotoxicity by suppressing ERK activation induced by CER.

A thymulin analogue peptide with powerful inhibitory effects on pain of neurogenic origin

The effects of a synthetic peptide analog of thymulin (PAT) were tested on nociceptive behavior in two animal models for peripheral mononeuropathy and in another two models for capsaicin-induced hyperalgesia. Treatment with PAT (0.25-25 microg/rat, i.p.) produced significant reduction of the mechanical allodynia and heat hyperalgesia in rats subjected to either chronic constriction injury (CCI) or spared nerve injury (SNI) models for mononeuropathy. Cold allodynia was moderately reduced in the CCI model. The inhibition of neuropathic manifestations peaked at 1-2 h post-treatment and disappeared in 3-4 h. Daily treatment with PAT, however, produced progressive attenuation of all neuropathic manifestations in the SNI model. On the other hand, pretreatment with similar doses of PAT produced dose-dependent reduction of the hyperalgesia induced by intraplantar injection of capsaicin (10 microg in 50 microl). The highest dose of PAT (50 microg) produced significant reduction of abdominal aversive behavior induced by i.p injection of capsaicin (20 microg in 100 microl). Compared with the effects of treatment with morphine or meloxicam (injected at single doses known to produce analgesia), PAT exerted equal or stronger inhibitory effects on neuropathic manifestations. The reported results suggest a possible direct action of PAT on afferent nerve fibers but its mechanisms remain to be determined.

[Effect of thymostimulin on endocrine thymus function in thyroidectomized rats during suppressive hormone therapy]

Due to disorders of hormonal balance in the organism, a decrease in thymic endocrine function occurred in rats after thyroidectomy. After removing the thyroid gland, we observed 1,3-2,2-fold decrease in the level of thymic hormone thymulin in the blood serum. When thyroxin was applied at a suppressive dose, endocrine function of the thymus did not restore. Injections of thymostimulin (Tp1) or its combination with thyroxin to thyroidectomized animals restored the level of thymulin up to the level in the intact rats due to effects of either injected preparation or induction of substances possessing thymosine-like activity.

FTS reduces bleomycin-induced cytokine and chemokine production and inhibits pulmonary fibrosis in mice

Bleomycin (BLM), an antitumour drug, is known to cause interstitial pneumonia followed by pulmonary fibrosis, and has often been used to produce an animal model of pulmonary fibrosis. In the present study, we examined the effect of a nonapeptide thymic hormone, facteur thymique serique (FTS), on the murine lung fibrosis induced by intratracheal instillation of BLM. Treatment with FTS ameliorated BLM-induced fibrotic changes in a dose-dependent manner, as indicated by the reduced accumulation of hydroxyproline (HP). In addition, FTS suppressed BLM-induced cellular inflammatory response in the lungs, as evidenced by inhibition of increased lung weight, reduced accumulation of inflammatory leucocytes, including lymphocytes and neutrophils, but not macrophages, and less pronounced histopathological changes. Finally, BLM challenge increased the local synthesis of proinflammatory cytokines, TNF-alpha and IL-1beta and chemokines, MCP-1, MIP-1alpha RANTES, MIP-2 and KC, while administration of FTS suppressed the production of these cytokines, except for MCP-1. These effects of FTS were observed only when mice received intratracheal instillation with BLM. Considered collectively, our results indicated that FTS treatment ameliorated the cellular inflammatory responses and fibrotic changes in the lungs caused by BLM and such inhibition was well correlated with reduced synthesis of several fibrosis-related cytokines, and suggested that FTS may be potentially useful for the treatment of pulmonary fibrosis.

Induction of early immunopotentiation to Fimbriae of Salmonella Enteritidis (SE) by administering thymulin and zinc to SE-vaccinated chicken breeders: relationship to protection

The purpose of this study is to attempt the induction of early immunopotentiation of antibodies specific to fimbriae of Salmonella enterica serovar Enteritidis (SE), by administering thymulin and zinc to SE-vaccinated chicken breeders, and the improvement of protection against a controlled-live challenge by SE. The first two groups of breeders were administered subcutaneously at 15 and 19 weeks of age a killed SE vaccine. Breeders of the third and fourth groups were left unvaccinated. Breeders of the first group, immunopotentiated by thymulin and zinc, were able to induce the earliest antibodies in their pooled sera at 2 weeks post the first SE-vaccination, specific to fimbriae (approximately 21 KDa) of SE. However, the second group that was only vaccinated with the same SE-vaccine produced specific antibodies to fimbriae at 3 weeks following the second vaccination (22 weeks of age). Breeders of the third group, that were neither SE-vaccinated nor immunopotentiated by thymulin and zinc, but were challenged by live SE at 22 weeks of age, were able to show specific antibodies to fimbriae at 3 weeks post challenge (25 weeks of age). The fourth group that was deprived of SE-vaccination, immunopotentiators, and challenge didn't show any background antibodies specific to SE-fimbriae. The presence of the earliest antibody-immunopotentiation to fimbriae of SE in breeders of the first group, administered thymulin and zinc, was associated with the lowest frequency of SE-infected ceca (10%) among the challenged groups. In addition, breeders of the first group were the only challenged birds resulting in absence of SE infection in their cecal tonsils. The first group-vaccinated, immunopotentiated, and challenged, and the second group-vaccinated and challenged only resulted in breeders with absence of SE infection in their oviducts and spleens. In conclusion, immunopotentiation of chicken breeders by thymulin and zinc induces the earliest specific antibodies to fimbriae of SE associated with the lowest frequency of SE-infected ceca, and absence of SE infection from cecal tonsils, oviducts and spleens.

A thymic hormone protects mice from enteropathy during acute graft-versus-host disease

We have previously reported that a nonapeptide thymic hormone, facteur thymique serique (FTS), is involved in the differentiation and activation of intestinal intraepithelial lymphocytes (i-IEL) in mice. In this study, we examined the effect of FTS treatment on enteropathy in a murine model for acute graft-vs.-host disease (GVHD) induced by injection of parental C57BL/6 splenocytes into unirradiated (C57BL/6 x DBA/2) F1 hybrids. FTS treatment significantly protected mice from developing acute GVHD as assessed by mortality rate, splenomegaly and enteropathy. The infiltration of donor-derived TCR alpha beta i-IEL bearing CD8 alpha beta was significantly inhibited in the small intestine of FTS-treated mice, and the frequencies of apoptosis of crypt cells in the intestinal mucosa were decreased in these mice during acute GVHD. These results suggest that FTS treatment contributes to protection against enteropathy of acute GVHD. Thus, FTS may provide a useful approach to control acute GVHD after blood transfusion or bone marrow transplantation.

Effects of a nonapeptide thymic hormone on intestinal intraepithelial lymphocytes in mice following administration of 5-fluorouracil

A significant fraction of murine small intestinal intraepithelial lymphocytes (i-IELs) mature in local sites outside the thymus. However, there is evidence suggesting that extrathymic differentiation of i-IELs is still influenced by the thymus or thymus-derived factors. Facteur thymique serique (FTS), a nonapeptide thymic hormone, is involved in several aspects of intra- and extrathymic T cell differentiation in vivo. In this study, we investigated the effects of FTS on the kinetics of i-IELs in mice following a single administration of 5-fluorouracil (5-FU). FTS treatment significantly accelerated the recovery in cell number of i-IELs after administration of 5-FU. Flow cytometric analysis revealed that this accelerated recovery was mainly due to a rapid increase in CD8 alpha alpha+ i-IELs. Similar findings were also evident in adult thymectomized (ATX) mice, indicating that FTS treatment caused a rapid recovery of CD8 alpha alpha+ i-IELs following 5-FU administration in the absence of a functional thymus. Furthermore, expression levels of the mRNAs for interleukin-2, interferon-gamma, and transforming growth factor beta 1 in the i-IELs were augmented by FTS treatment. Notably, FTS treatment protected mice from 5-FU-induced lethal toxicity, accompanied with an inhibition of the translocation of Enterobacteriaceae. These results suggest that FTS has an important function in the extrathymic maturation and activation of i-IELs in the small intestine following 5-FU administration, which may contribute at least partly to the protection against 5-FU-induced lethal toxicity.

In vivo administration of serum thymic factor (FTS) prevents EMC-D virus-induced diabetes and myocarditis in BALB/cAJcl mice

The effect of serum thymic factor (FTS) on the D-variant of encephalomyocarditis (EMC-D) virus-induced diabetes and myocarditis in BALB/cAJcl mice was investigated. Mice pretreated with 50 or 10 micrograms of FTS were infected with 10 or 10(3) PFU of EMC-D virus. In the mice inoculated with 10 PFU of virus, 40% developed diabetes on post-infection day (PID) 14, whereas those treated with FTS (50 micrograms/administration) on day 2 and 1 before infection did not develop diabetes. FTS (10 micrograms)-pretreated mice developed diabetes. In histological observation, FTS non-treated mice which developed diabetes showed severe necrosis and inflammation of mononuclear cells in the islets of Langerhans and myocardia on 19 PID. Mice pretreated with 50 micrograms of FTS, however, manifested mild islet degeneration without any myocardial inflammation. Furthermore, in FTS non-treated mice, immunohistological staining showed a loss of insulin granules. This loss was markedly reversed and insulin granules remained largely intact in FTS-pretreated mice. Viral titers in pancreas of FTS-pretreated mice approximated well to those of non-treated mice on PID 4, 7 and 19. In mice inoculated with higher titer of EMC-D virus (10(3) PFU), however, 50 micrograms of FTS pretreatment did not change the course of these acute pathological developments (diabetes and myocarditis observed from PID 4).

Resistance to pseudorabies virus with enhanced interferon production and natural killer cell activity in mice treated with serum thymic factor

Susceptibility to pseudorabies virus (PRV) infection in mice, which were continuously depleted of natural killer (NK) cell activity by injection of anti-asialo GM1, was examined. Effects of serum thymic factor (FTS) on susceptibility of mice to PRV were also investigated. In mice with depleted NK cell activity, the mortality of PRV-infected mice was markedly high, whereas that of FTS-pretreated mice was significantly lower than the controls. Reduced susceptibility to PRV was demonstrated in mice treated with anti-asialo GM1 antisera before the PRV infection. Such a reduced susceptibility was not observed in mice inoculated with the antisera on day 1 post-infection (PI). To analyze the FTS-induced resistance to PRV infection, NK cell activity, macrophage activity, and interferon (IFN) productions were studied. Interferon production and NK cell activity were enhanced in the FTS-pretreated mice, suggesting that interferon may play an important role in this FTS-induced resistance to PRV infection.

Thymulin and its role in immunomodulation

Even though thymulin was isolated, sequenced and characterised some 20 years ago and later identified as a thymic hormone involved in immunomodulation, much more work is still required to further understanding of the mechanisms of action(s) of this peptide. Since the observation, by a semiquantitative bioassay, of diminished levels of thymulin in immunodeficiency and autoimmune disease, new data obtained by radioimmunoassay have not only confirmed previous observations but also demonstrated that thymulin plays a role in the interaction between the immune system and the neuro-endocrine system. In this paper we give an up to date account of recent developments in research into the role of thymulin in immunomodulation.

Radioprotective effects of serum thymic factor in mice

Serum thymic factor (FTS) reduced mortality of mice after total-body irradiation with 7.56 Gy X rays. The radioprotective effect was achieved by daily repeated subcutaneous injections of 3-100 micrograms FTS, while doses higher than 300 micrograms/day/mouse were neither radioprotective nor toxic. Similarly, degeneration of the spleen was moderated by 3-100 micrograms FTS but not by 500 micrograms FTS in sublethally (3.78 Gy) irradiated mice. Histological examination showed that hematopoiesis was enhanced in the spleen by daily injections of 10 micrograms FTS. Spleen cells from the FTS-treated mice incorporated more [3H]thymidine in culture with or without concanavalin A. The treatment with FTS increased the production of colony-stimulating factor in the spleen as well as in peritoneal macrophage-like cells, and caused a significant increase in the number of granulocyte-macrophage colony-forming cells both in the spleen and in the femoral bone marrow. Furthermore, FTS prevented a decrease in circulating neutrophils in the sublethally irradiated mice. Prominent overshoot recovery of myelopoiesis, which occurred occasionally in sublethally irradiated mice, did not occur in the FTS-treated mice. The decrease in blood erythrocytes was also significantly reduced. These observations imply that this thymic hormone has potential as a radioprotector.

Thymic atrophy in type 2 reovirus infected mice: immunosuppression and effects of thymic hormone. Thymic atrophy caused by reo-2

Suckling mice infected with reovirus type 2 showed a thymic atrophy followed by a marked suppression of the antibody, production to SRBC (a T cell dependent antigen) and bacterial LPS, when measured by the splenic PFC assay. The PFCs produced were sometimes less than 1% of uninfected control animals. Histologically the thymus was usually smaller than normal, and atrophy of the cortex and increased number of Hassal's bodies were observed. Number of nucleated cells in the thymus of infected mice showed 90% decrease as compared to uninfected mice. The spleen, although larger in size, showed depletion of lymphocytes from the thymus-dependent and follicular areas. No viral replication was detected in lymphatic organs using virological methods. Virus-infected mice transferred with the splenocytes or thymocytes from age-matched uninfected mice restored the antibody production against SRBC to normal levels. Thymocytes were more efficient than splenocytes in enhancing the antibody production in virus-infected mice. Injection of several different kinds of immunopotentiating agents enhanced the antibody production to SRBC, although LPS exacerbated the unresponsiveness. Thymic hormones such as FTS and TP5 enhanced antibody production to SRBC and LPS more efficiently than MDP. Flow cytometric analysis showed that percentage of CD4+ single positive cells was slightly increased in virus-infected mice treated with FTS, while there was no difference in the phenotypic distributions of thymocyte subpopulations among virus-infected mice, FTS-untreated and FTS-treated normal mice.

Nonathymulin treatment of multiple sclerosis: double-blind pilot study

We carried out a randomized, double-blind, placebo-controlled trial of Nonathymulin (NT, synthetic serum thymic factor) in patients with evolutive multiple sclerosis (MS) and moderate disability. Forty matched patients were treated with subcutaneous NT or placebo for 6 months and followed for another 6 months. There was no significant difference in treatment and control groups in the Kurtzke. Disability scores, Ambulation Index and Functional Scale. No significant side effects were recorded. NT is not effective in treating evolutive and moderately disabled MS.

Thymulin, a zinc-dependent hormone

Thymulin (formerly called FTS) is a well defined nonapeptide hormone produced by thymic epithelial cells. Its biological activity and antigenicity depend upon the presence of the metal zinc in the molecule. This pharmacologically active metallopeptide induces the differentiation of T-cells and enhances several functions of the various T-cell subsets in normal or partially thymus-deficient recipients. Its effect on suppressor T-cells is, so far, the most remarkable and should be the first to find useful clinical applications. The peptide is a natural hormone, available in synthetic form. It is not toxic and one may foresee its clinical use as one of the major immunoregulatory agents in the near future.

Suppression of acute experimental allergic encephalomyelitis by synthetic serum thymic factor. Clinical, histopathological, and immunohistochemical studies

Acute experimental allergic encephalomyelitis (EAE) was induced in Hartley guinea pigs and Lewis rats, which were then treated with synthetic serum thymic factor (FTS). When a dose of 30 micrograms/100 g body weight of FTS was subcutaneously administered to the animals on days--1 (before inoculation), 4, 9 and 15 intermittently, clinical symptoms of acute EAE were suppressed. Histopathological evaluation showed that the severity of EAE in FTS-treated guinea pigs was less than in untreated guinea pigs. Immunohistochemical examination showed that the numbers of OX6+, W3/25+, W3/13+ and OX19+ cells in FTS-treated rats were less than in untreated rats and that the number of OX8+ cells in FTS-treated rats was greater than in untreated rats. These findings suggest that FTS induced OX8+ cells in inflammatory lesions and suppressed inflammation in acute EAE.

Nonathymulin in rheumatoid arthritis: two double blind, placebo controlled trials

Two randomised double blind, placebo controlled trials have been carried out to assess the effectiveness of nonathymulin, a synthetic thymic peptide hormone, in the treatment of rheumatoid arthritis (RA) and to compare three different dosage schedules (1, 5, and 10 mg/day). Nonathymulin 5 mg proved to be the most efficient dose, providing significant clinical improvement as evaluated by the global assessment of all patients who entered the trials (56% v 17% in the placebo group) (p less than 0.02) and by four objective parameters. This effect was accompanied with minimal adverse effects and was not associated with clear changes in immunological parameters. A significant correlation was observed, however, in clinical response to nonathymulin, and T cell subset imbalance was assessed using monoclonal anti-T cell antibodies and a functional suppressor T cell assay.

[Immunoactive peptides]

Perspectives for use of four groups of immunoactive peptides in medico-biological investigations are considered. Glycopeptides, fragments of bacterial cell walls and their analogues, exhibited distinct modulating effect both on humoral and cell systems of immunity as well as the antitumoral action. Mechanisms of action of these substances are discussed. Synthesis and biological effect of thymus blood serum factor and of its simplified analogues are described. Perspectives for use of synthetic peptides in development of artificial vaccines are considered. Isolation of an antigenic determinant from surface protein of aphthous fever virus and its physico-chemical properties are described. Possible approach for control of the immunological status by means of neuropeptides was demonstrated using the delta sleep peptide. The delta sleep peptide and its cyclic analogue at microgram doses prevented the impairments caused by stress in the system of natural antitumoral resistance in mice.

Marked reduction of DNA antibody production and glomerulopathy in thymulin (FTS-Zn) or cyclosporin A treated (NZB X NZW) F1 mice

In this study we have evaluated the action of two compounds, cyclosporin A (Cy A) and thymulin (FTS-Zn) in old (NZB X NZW) F1 male mice which develop severe autoimmune disease. Compared with control mice, thymulin and Cy A treated mice already showed by 2 weeks a dramatic diminution of their anti-DNA antibody level which remained low throughout the treatment period and persisted for 7 weeks afterwards. Renal specimens were studied by direct immunofluorescence in Cy A and thymulin treated mice. Glomerular deposits were decreased compared with control mice; these differences were particularly clearcut for IgG1 and IgG2 deposits. Finally, thymulin (FTS-Zn) and Cy A appeared to induce the same improvement of DNA titres and glomerulopathy in (NZB X BW) F1 mice.

Effect of thymus factor and levamisole treatment in patients with persistent nephrotic syndrome

The effects of thymus factor (TFX) and levamisole on the clinical picture and some indices of cellular immunity have been evaluated in 10 patients with nephrotic syndrome due to membranoproliferative glomerulonephritis Type I. The patients revealed decreased T-lymphocyte number and impaired responsiveness to phytohaemagglutinin (PHA) stimulation before treatment. An association between the slight diminution of proteinuria and the increase of E-rosette forming lymphocytes, increased responsiveness to PHA and return to normal of previously elevated B-cell percentages, was observed in four patients treated with TFX and one patients treated with levamisole.

Improvement of cellular immunity and IgA production in immunodeficient children after treatment with synthetic serum thymic factor (FTS)

Three children with IgA and IgE deficiency and T-cell defects (two related patients with ataxia telangiectasia and one with common variable immune deficiency) were treated with synthetic serum thymic factor (FTS) intravenously. A reduction in frequency and severity of infection was noted concomitantly with improvement in cell-mediated-immunity tests. Serum IgA, which was absent in two patients, appeared within 4 weeks of treatment and increased significantly in the third patient. Specific antibodies against vaccination antigens appeared for the first time or increased to titres higher than ever before. In two patients, transient interruption of FTS administration was followed by a regression of the immunological improvement, but this disappeared after the treatment was started again.

The effects of immunomodulation on peripheral T cell subsets

Monoclonal antibody assays were employed to monitor modifications induced in human peripheral lymphocyte subsets by thymectomy or the administration of a series of immunomodulating drugs: synthetic thymic factor, cimetidine or various combinations of anti-thymocyte globulin, azathioprine and steroids. In patients with myasthenia gravis, thymectomy produced a gradual progressive decrease in the elevated OKT4/OKT8 ratios associated with this disease until normal ratios were achieved after one year. Administration of synthetic thymic factor to three immunodeficient children for one month produced increased serum IgA levels accompanied by a normalization of proportions of total T cells and T cell subsets. Four of five uremic patients receiving cimetidine exhibited a marked increase in the percentage of OKT8+ T cells observed in subsequent blood samples with a concomitant increase in immature (OKT4+, OKT8+) lymphocytes that suggested an increase in release of such lymphocytes from the thymus. Assessment of 29 longterm renal allograft recipients by repeated T cell monitoring over an extended period of time confirmed the findings of other investigators that an increase in the OKT4+/OKT8+ ratio was predictive of subsequent allograft rejection episodes while subnormal OKT4+/OKT8+ ratios were indicative of possible cytomegalovirus or herpes virus infections.

Human postthymic precursor cells in health and disease. II. Their loss and dysfunction in systemic lupus erythematosus and their partial correction with serum thymic factor

We have recently described that human autologous rosette-forming (Tar) cells have the characteristics of postthymic precursor cells. Herein we report that we found circulating Tar cells significantly diminished in 32 patients with untreated systemic lupus erythematosus (SLE) as compared to 32 age/sex matched controls. Pretreatment of peripheral blood mononuclear cells (MNC) from SLE patients with serum from young normal adults or wtih serum thymic factors (FTS) increased their percentages of Tar cells significantly but reached near normal values in only 3 patients with inactive disease. Patients and normal subjects had similar percentages of Tar cells binding peanut-agglutinin. Characteristic functions of postthymic precursor cells are feedback inhibition and generation of suppressor cells which we studied in systems where we depleted or added Tar cells to Tmu and B cells, or MNC, respectively, using as indicators the production of immunoglobulins measured in culture supernatants or 3H-thymidine incorporation. We found both functions diminished in SLE patients despite using the presence of a qualitative as well as quantitative defect. In two SLE patients studied both of these functions corrected partially when their Tar cells were pretreated with FTS. In 20 SLE patients we studied Tgamma and Tmu cells as well as Concanavalin-A-induced, spontaneously-expanded suppression and found Concanavalin-A-induced, spontaneously-expanded suppressor function and Tgamma cells diminished. However only the reduction of Tgamma and of spontaneously-expanded suppressor function were found to relate to disease activity. On the other hand, Tmu cells were found to be similar in numbers in SLE patients and normal controls.

Effect of long-term treatment with circulating thymic factor on murine lupus

Mice from three different strains (NZB, B/W, and Swan) which spontaneously develop a lupus-like disease and show a premature decline of their secretion of the circulating thymic factor, Facteur Thymique Sérique (FTS), were treated repeatedly with FTS and followed for the evolution of their autoimmune disease. The autoimmune sialoadenoitis (Sjögren's syndrome) appearing in NZB and B/W mice, evaluated here by a scintigraphic method, was completely prevented or even cured by FTS treatment. The increase in anti-erythrocyte autoantibody production was transiently delayed in aged NZB mice. Conversely, antiDNA antibody production either remained unaffected or was accelerated (in B/W mice) by FTS treatment. These results demonstrate that the restoration of the failing thymic secretion does influence autoantibody production, in a manner depending primarily on the autoantigen eliciting the autoimmune response. However, caution is urged in the application of this approach to human lupus without further studies.