Circulating thymic hormone activity in patients with primary and secondary immunodeficiency diseases

Existing knowledge on Zn status biomarkers (1963-2021) with a particular focus on FADS1 and FADS2 diagnostic performance and recommendations for further research

The role of Zn in human health was discovered 60 years ago, and despite remarkable research efforts, a sufficiently sensitive and specific biomarker of Zn status is still lacking. Plasma/serum Zn, currently the best available and most accepted population Zn status indicator, responds well to severe Zn deficiency, yet, mild to moderate Zn deficiency states usually remain unrecognized. Identifying early-stage Zn deficiency requires additional robust markers of Zn status. This paper discusses the sensitivity, specificity, and responsiveness of plasma Zn concentrations to Zn interventions. It describes the biochemical and dietary basis for the causal association between Zn and fatty acid desaturases activity, FADS1 and FADS2, based on data collected through studies performed in animals and/or humans. The influence of potential confounders and covariates on the observed relationships is considered. Additional potential Zn biomarkers are discussed and suggestions for further research in this area are provided.

Thymulin and the neuroendocrine system

Thymulin is a thymic hormone exclusively produced by the thymic epithelial cells. It consists of a nonapeptide component coupled to the ion zinc, which confers biological activity to this molecule. After its discovery in the early 1970, thymulin was characterized as a thymic hormone involved in several aspects of intra- and extrathymic T-cell differentiation. Subsequently, it was demonstrated that thymulin production and secretion is strongly influenced by the neuroendocrine system. Conversely, an emerging core of information points to thymulin as a hypophysotropic peptide. Here we review the evidence supporting the hypothesis that thymulin is an important player in the hypophyso-thymic axis.

Pineal modulation of thymus and immune function in a seasonally breeding tropical rodent, Funambulus pennanti

The immune system driven by cytokines is now known to be influenced by various other endocrine glands and its hormones. Results of the present study indicate a bidirectional relation between the pineal-thymus axis and the immune system status of an Indian tropical rodent, Funambulus pennanti, during winter months (reproductive inactive phase), when it faces maximum challenges from nature. Pinealectomy during the reproductive inactive phase inhibited thymus and spleen functions, which resulted in significant changes in leukocyte and lymphocyte counts and T-cell-mediated immune function (measured in terms of delayed-type hypersensitivity response to oxazolone). Blastogenic responses of lymphoid cells (thymocytes, splenocytes, and lymph node cells) also decreased following ablation of the pineal gland. To check the definite role of the pineal gland we injected melatonin into pinealectomized squirrels, and the suppressed immune function was significantly restored. Neuroendocrine control of the pineal gland on the histocompatible tissues in this seasonal breeder, F. pennanti, suggests an adaptive mechanism of the immune system for survival in the tropical zone. J. Exp. Zool. 289:90-98, 2001.

Distribution of age-related thymulin titres in normal subjects through the course of life

The thymus has a dominant immunological role in utero and in early childhood, being a primary source of T lymphopoiesis, and its investigation may be particularly relevant for the immunological study of paediatric patients. Thymulin, a nonapeptide secreted by the thymus, is an essential hormone for T lymphocyte differentiation and function. As thymulin values in the normal population have not been well documented, especially for children under the age of 1 year, we detail thymic endocrine function by presenting age-related plasma thymulin levels in a large series (n = 93) of healthy individuals, ranging from birth to old age. We demonstrate that thymulin is already detectable at birth; it then gradually increases with age, reaching the highest level in children aged 5-10 years. Starting at adolescence, thymulin titres gradually start to fall, reaching the lowest value at 36 years of age and remaining steady until 80 years (the oldest person tested).

Increased spontaneous apoptosis in T lymphocytes in DiGeorge anomaly

The aim of this study was to determine whether increased apoptosis in peripheral blood lymphocytes plays a role in T cell deficiency associated with DiGeorge anomaly. T cell subsets from a patient with DiGeorge anomaly were examined for the expression of Fas, FasL, Bcl-2 and Bcl-XL at the protein level with monoclonal antibodies, using dual-colour flow cytometry, and at the mRNA level in mononuclear cells by quantitative reverse transcriptase-polymerase chain reaction. In vitro spontaneous apoptosis was examined by propidium iodide staining and DNA fragmentation, using flow cytometry and gel electrophoresis, respectively. Fas and FasL expression, both at the level of protein and of mRNA, was increased, whereas Bcl-2 expression was decreased both at the level of protein and of mRNA. However, no difference in Bcl-XL expression was observed between the patient and an age-matched control. A significant proportion of both CD4+ and CD8+ T cells from the patients underwent spontaneous apoptosis, whereas almost no spontaneous apoptosis was observed in the age-matched control. These data suggest that spontaneous apoptosis in T lymphocytes, at least in part, may be responsible for T cell deficiency in DiGeorge anomaly.

New perspectives on use of thymic factors in immune deficiency

Current knowledge on the role of thymic factors in the immune response is inadequate and remains relatively primitive when compared with present technical possibilities for assessing lymphocyte subsets or cytokine interaction. New studies support the potential importance of thymic factors as regulators of immune interactions. Indirect evidence supports the concept that thymic factors may work at the level of IL-2. The functional identity of cells responsive to thymic factors and the relation of observed effects to cytokine network interactions need to be established. The use of thymic factors in the future will depend on the development of criteria to identify appropriate settings in which to use such factors and the implementation of appropriate measures of immune functional response.

Depressed monocyte polarization and clustering of dendritic cells in patients with head and neck cancer: in vitro restoration of this immunosuppression by thymic hormones

The in vitro restoring effects of a thymic hormone preparation, TP-1, on defective monocyte and dendritic cell function in patients with head and neck squamous cell carcinoma (HNSCC) have been examined. The N-formylmethionyl-leucyl-phenylalanine (fMLF)-induced polarization of monocytes isolated from the peripheral blood was significantly lower (a mean of 19%) than the polarization of monocytes isolated from healthy controls (a mean of 33%). After the in vitro addition of TP-1 this defective polarization was improved to the normal value of 33% polarized monocytes. The capability of dendritic cells prepared from the blood to form cellular clusters with allogeneic cells was impaired in 26/44 patients. In vitro addition of TP-1 again had restoring effects. The original defective dendritic cell clustering of 97 clusters/six microscopic fields (mean) was improved to a value of 121 clusters. The defects in monocyte polarization and clustering of dendritic cells could be ascribed to the presence in serum of a tumor-derived low-molecular-mass factor low-M(r) factor; < 25 kDa) sharing structural homology with p15E, the capsular protein of murine and feline leukemogenic retroviruses. The incubation of low-M(r) factor from the serum of HNSCC patients with healthy donor monocytes resulted in a significantly higher inhibition of fMLF-induced monocyte polarization than did incubation with control low-M(r) factor (a mean of 42 versus 16% inhibition). This suppressive effect of patient low-M(r) factor was abrogated with a mixture of two monoclonal antibodies against p15E as well as with TP-1. The observations here reported on the in vitro effects of TP-1 on depressed monocyte and dendritic cell function in HNSCC have provided one of the rationales for a TP-1 therapeutic pilot trial recently started in HNSCC patients.

Interactions between the hypothalamo-pituitary adrenal axis and the thymus in the rat: a role for corticotrophin in the control of thymulin release

Our recent observations in man suggested that the secretion of the thymic peptide, thymulin, is influenced by hormones of the pituitary-adrenal axis. In the present study, we have used the rat as a model in order to examine 1) the effects of corticotrophin (ACTH) and glucocorticoids on the release of thymulin in vivo and in vitro, and 2) the influence of an acute rise in plasma thymulin on the secretion of corticosterone and luteinizing hormone. Immunoreactive thymulin was readily detectable in plasma from male Sprague-Dawley rats(≃200 g). Chronic bilateral adrenalec-tomy, which effectively removed endogenous corticosterone, produced highly significant (P<0.01) increases in the plasma concentrations of both ACTH and thymulin. Treatment of the adrenalectomized rats with dexamethasone, in a dose sufficient to suppress the hypersecretion of ACTH, maintained the plasma thymulin at a low level which did not differ significantly (P > 0.2) from that in sham-operated controls. In vitro, two non-specific depolarizing agents, K(+) (56 mM) and veratridine (10 ≃M), caused significant (P<0.01) Ca(2+) -dependent increases in thymulin release from segments of rat thymic tissue. Their effects were mimicked by ACTH(1-39) . The secretory responses to ACTH (0.025 to 1 ng/ml) were concentration-dependent but a very high concentration (2 ng/ml) of the peptide was without effect. Dexamethasone (0.1 μM) reduced (P<0.05) the spontaneous release of thymulin in vitro but potentiated markedly (P<0.01) the secretory responses to ACTH (0.5 to 1.0 ng/ml). Administration of thymulin (0.1 and 10 μg/kg ip) produced, within 10 min, striking increases in the plasma thymulin concentration which were still evident at 30 min. The peptide concentration then declined rapidly and, within 24 h, was lower than that in the corresponding vehicle-treated controls. The serum concentrations of corticosterone and luteinizing hormone were unaffected by the thymulin treatment. The saline vehicle (2.0 ml/kg ip) also produced a small increase in plasma thymulin concentration which was maximal at 10 min; a further small rise was evident 6 h after the injection but thereafter the thymulin values were indistinguishable from those in uninjected controls. A similar biphasic profile of serum corticosterone was apparent after the saline injection but the serum luteinizing hormone was unaffected. The results suggest that ACTH is a physiological enhancer of thymulin release and that, in certain circumstances, its effects may be potentiated by glucocorticoids.

Effect of thymic extract on blastogenic responses of chickens

Chickens were treated intracoelomically with extracts of chicken thymus (TE) and bursa of Fabricius (BE), the former known to be enriched with avian thymic hormone. Doses of 1.0 mg TE enhanced blastogenic responses of peripheral blood lymphocytes to phytohemagglutinin (PHA) and concanavalin A for at least 3 wk after cessation of treatment. Very high doses of BE (5.0 mg) also enhanced blastogenic responses to PHA.

Establishment of a sensitive radioimmunoassay for serum thymic factor with a special reference to extraction procedures

A radioimmunoassay (RIA) for serum thymic factor (facteur thymique serique) was established. This assay could detect less than 0.5 pg of serum thymic factor without the interference by other thymic hormones, including thymopoietin II and thymosin alpha 1. Both zinc-free and zinc-bound serum thymic factor showed a similar standard curve, indicating that this RIA could detect both forms of serum thymic factor in the same way. We observed that two procedures were required prior to the measurement in order to measure serum thymic factor content in plasmas; the first, the extraction procedure to remove substances interfering with the assay nonspecifically; the second, the storage of the sample with ethylenediamine tetraacetic acid disodium salt to inhibit the proteases in the plasma to degrade serum thymic factor. By employing this assay system, we observed that cord blood plasmas contained significantly higher level of serum thymic factor than did adult blood plasmas.

Reversal of ageing changes in the thymus of rats by chemical or surgical castration

Differences in the thymus of young and old male CSE Wistar rats were examined by use of routine histological stains on paraffin-embedded sections. There was a highly significant loss of thymic weight and disruption of architecture with age. Both surgical castration and chemical castration induced by a luteinizing hormone-releasing hormone analogue (Goserelin) caused a significant increase in thymic weight and the reappearance of a well-defined cortex and medulla in ageing rats. Cell surface antigens were detected on cryosections after incubation with a range of monoclonal antibodies. The Pan T cell marker (detected with antibody W3/13) showed fewer positive cells in ageing rats, and an increase after chemical castration. The smaller glands of old rats had fewer positive T cells with CD4 (MRC OX35) and CD8 (MRC OX8) antigens, and more after chemical castration in both young and ageing rats, but the greatest changes were seen in the intensity of Class II major histocompatibility complex (MRC OX6) immunoreactivity. In both young and ageing chemically-castrated rats, the number of cells and the intensity of immunoreactivity were greatly increased in the medulla.

Effects of repeated administrations of facteur thymique sérique (FTS) on biochemical changes related to aging in senescence-accelerated mouse (SAM)

Superoxide dismutase (SOD) activity,malondialdehyde (MDA) content and monoamine oxidase B (MAO-B) activity were measured in the brain, liver and kidney of a normal aging strain (R/1) and an accelerating aging strain (P/8) senescence-accelerated mice (SAM) at 9-10 months of age, and the effects of facteur thymique sérique (FTS) were examined. The activity of Cu,Zn-SOD in the kidney and MAO-B in the liver was significantly low and high in SAM-P/8 compared to SAM-R/1. FTS enhanced the activity of Mn-SOD and Cu,Zn-SOD in the kidney of SAM-P/8 and Cu,Zn-SOD activity in the brain of both SAM-P/8 and SAM-R/1. It decreased the activity of MAO-B in the liver and the contents of malondialdehyde (MDA) in the brain and kidney of SAM-P/8. Thus, FTS affects the biochemical factors related to senescence in SAM-P/8, a particular senescent animal model, and may thus possibly be effective as an anti-senescent medicine.

Beneficial effects of the thymic hormone preparation thymostimulin in patients with defects in cell-mediated immunity and chronic purulent rhinosinusitis. A double-blind cross-over trial on improvements in monocyte polarization and clinical effects

Twenty patients with chronic purulent rhinosinusitis were treated with TP-1 (Serono; 1 mg/kg body weight), in a double-blind cross-over trial. TP-1 was administered by daily i.m. injections for the first 14 days followed by two injections/week for 6 further weeks. The patients were immunologically special in that they had defects in their cell-mediated immune system. Fourteen showed a decreased chemotactic responsiveness of their peripheral blood monocytes as measured in the polarization assay. This defective function can probably be ascribed to the presence in serum of low molecular weight factors (LMWFs; less than 25 kD). As reported earlier, this factor shows a structural homology to the envelope protein of murine and feline leukaemia virus (P15E). Thirteen patients showed a defective delayed-type hypersensitivity (DTH) skin test reactivity towards candidin and/or streptokinase-streptodornase (Sk/Sd) antigen, 14 had a defective MIF production from their peripheral blood lymphocytes towards candidin, Sk/Sd and/or Haemophilus influenzae antigen. Eighteen patients completed the TP-1 trial and showed clinical improvements: 12 out of 15 were feeling better during TP-1 therapy and the nasal mucosa showed on inspection absent mucopurulent secretion in 13 patients. Positive bacterial culture rates for the nose decreased from 14 out of 16 to five out of 15. Placebo treatment had no significant effects. The clinical improvements were accompanied by a better performance of the cell-mediated immune system; the most significant effects were recorded in the monocyte polarization assay. The suppressive P15E-like LMWFs in serum clearly decreased during TP-1 treatment. In vitro TP-1 neutralized the immunosuppressive effect of the LMWFs. The restoring effects of TP-1 on monocyte polarization and its neutralizing activity of P15E-like LMWFs could explain the beneficial effects of thymic hormone treatment reported in adults with clinical signs of immunodeficiency in the presence of a full T cell repertoire.

A new radioimmunoassay for the thymic peptide thymulin, and its application for measuring thymulin in blood samples

A new, specific and sensitive radioimmunoassay, using a polyclonal antiserum raised in rabbits, is described for quantitating plasma thymulin. As little as 300 fg thymulin can be measured in one assay tube. The method has been used to measure thymulin in human blood (umbilical vessel blood, 2191 +/- 123 fg/ml; children and adults up to the age of 20 years, 1499 +/- 119 fg/ml; and adults between 21-65 years, 371 +/- 18 fg/ml). There is a highly significant decrease within these three groups (P less than 0.001 by one way analysis of variance). Also plasma thymulin levels were determined in rats (601 +/- 127 fg/ml) and in pooled plasma samples from mice (638 +/- 56 fg/ml). No thymulin was detected in plasma obtained from nude rats, nude mice and thymectomised mice. These results show that the radioimmunoassay described here is a useful quantitative tool for measuring plasma thymulin that will have applications in basic, applied and clinical research.

Genetic aspects of immunoglobulin A deficiency

IgA deficiency is one of the most common of all immune defects. While it is often not associated with clinical illness, presumably due to compensation from other sectors of the immune system, IgA-deficient individuals are distinctly more likely to become ill and have one or more of specific groups of diseases. While the unifying immunologic perturbation in IgA deficiency is a lack of mature IgA-secreting B cells, a host of other, usually minor, immunologic abnormalities have been reported in such patients. IgA deficiency can be inherited in an autosomal dominant or autosomal recessive fashion, but most individuals who are IgA deficient have no other affected family members. From a genetic point of view, IgA deficiency has been associated with three chromosomes, 18, 14, and 6. Many IgA-deficient individuals who have cytogenically detectable abnormalities of chromosome 18 have been reported, but all the individuals with these defects have severe congenital defects of other kinds. Obscuring the relationship between chromosome 18 and IgA deficiency is the fact that both short- and long-arm deletions have been reported in IgA deficiency. The chromosome deletions in the individuals who are IgA deficient thus appear to have no common pattern. While a rare individual can be IgA1 deficient on the basis of heavy-chain deletions of alpha 1 genes in concert with other heavy-chain genes on chromosome 14, such individuals are quite rare, and from a clinical point of view, those reported have usually been healthy. Absence of both IgA1 and IgA2 genes (presumably in concert with other heavy-chain genes) has never been reported. For chromosome 6, a more complex puzzle emerges. IgA-deficient individuals have been reported to have one of a few specific HLA haplotypes. While many individuals with these supratypes are not IgA deficient, these findings encourage the notion that the secretion of IgA could be at least partly controlled by genes residing in the major histocompatibility locus.

Relation between lymphocyte subpopulations and pineal function in patients with early or metastatic cancer

It has been demonstrated that melatonin and other pineal hormones play a role in the neuroendocrine control of immunity. Anomalies of both pineal and immune functions have been reported in cancer. Pineal and lymphocyte functions, however, have never been simultaneously evaluated in oncologic patients. This preliminary study was carried out in order to analyze the melatonin-lymphocyte relationship in human neoplasms. In a first investigation, we evaluated melatonin serum levels and lymphocyte subpopulations on venous blood samples collected during the morning from 46 healthy controls and from 27 cancer patients, 13 of whom had metastases, while the other 14 were without metastases. Moreover, melatonin levels were high in 10 oncological patients and within the normal range in the other 17 cases. B lymphocyte (B), total T lymphocyte (T3), T helper/inducer (T4) and T suppressor/cytotoxic (T8) mean percentages and T4/T8 mean ratios did not significantly differ, either between patients with high and normal melatonin levels, or between metastatic and nonmetastatic cancer patients. In a second study, we evaluated the effects of a prolonged treatment with melatonin (20 mg/daily intramuscularly at 3:00 p.m. for 2 months) on 8 patients with advanced cancer, in whom conventional antitumor therapies had failed. Mean percentages of B, T3, T4, T8 lymphocytes and T4/T8 mean ratios were not significantly different before or after melatonin treatment. In only one patient did the T4/T8 ratio decrease after therapy; in this case only, a stabilization of the disease was obtained, while in all 7 other patients the neoplastic disease progressed also during melatonin treatment, even if an evident improvement of the performance status was seen as it was in most cases. These results seem to exclude that melatonin may influence lymphocyte functions in cancer. Longitudinal studies and further data, however, will be needed to clarify this question.

Bone marrow transplantation in DiGeorge syndrome

A Hispanic infant girl with DiGeorge syndrome underwent successful bone marrow transplantation (BMT) at age 28 1/2 weeks. She had typical facies, a cardiac defect, hypoparathyroidism, severe T and B cell immunodeficiency, and low levels of facteur thymique serique (FTS). In vitro incubation of the peripheral blood lymphocytes with thymosin alpha 1 showed no increase in the number of T cells on two occasions. A fetal thymus for transplantation was not available, and further review of past experience with thymic cells or factors revealed inconsistent and incomplete responses. Because of the patient's worsening clinical and immunologic status, BMT was performed, with her histocompatible brother as donor. The patient has had a good clinical and immunologic response to BMT, with evidence of T cell engraftment, improved B cell function, and increased levels of serum FTS. This experience indicates that minimal thymic influence is necessary for successful BMT and that patients with DiGeorge syndrome with significant T cell deficiency may benefit from this treatment.

Circulating thymulin and thymosin-alpha 1 activity in pediatric acquired immune deficiency syndrome: in vivo and in vitro studies

Twenty-five children with acquired immune deficiency syndrome (AIDS) or AIDS-related complex had a characteristic pattern of T cell deficiency. Abnormally low plasma thymulin levels preceded the development of peripheral blood T cell abnormalities. In contrast to patients with congenital T cell deficiencies, our patients had elevated serum levels of thymosin-alpha 1. Treatment with thymosin fraction 5 in three children with AIDS resulted in only transient clinical and immunologic improvement.

Low circulating thymulin-like activity in children with AIDS and AIDS-related complex

Thymic secretory function was assessed by determining levels of circulating thymulin-like activity in plasma of 21 pediatric patients infected with the HTLV-III/LAV retrovirus. All the patients had serum antibodies against p41 antigens of HTLV-III on Western blot analyses. In accordance with the latest definition established by the Centers for Disease Control, 14 patients had the acquired immunodeficiency syndrome (AIDS) and the remaining 7 were classified as having AIDS-related complex. Their ages ranged from 1 to 7 years, with 10 being less than 1 year of age. Circulating thymulin activity, normally highest in healthy children under 15 years of age, was undetectable in 11 patients and below normal range for age in the remaining. OKT4/OKT8 ratios of T-cell subsets in peripheral blood were below normal in the majority of patients. Our findings suggest that thymic epithelial injury may be an early event in HTLV-III/LAV-related disease and may precede the development of clinical and/or immunologic aberrations.

Thymosin fraction 5: effects on T cell functions in mice immunosuppressed by severe dietary protein deficiency

The present studies were performed to determine the effects of severe protein deficiency and subsequent injection of thymosin fraction 5 (TF5) on T and B cell functions. BALB/c mice, 4 weeks old, were fed a normal protein (21%), a low protein (4%) or a protein free (0%) diet and then injected with TF5 or buffer (PBS). A significant increase was observed in the PHA (phytohemagglutinin) and LPS (lipopolysaccharide) induced mitogenesis with increasing age of the well-nourished, PBS injected animals. The severely protein malnourished mice, PBS injected and the well nourished mice, injected with TF5 had smaller increases in both B and T cell mitogenesis with increasing age. TF5 injection of the malnourished mice increased PHA and LPS mitogenesis nearly to the levels of the well-nourished mice. The protein malnourished mice consistently had higher serum corticosteroid levels than controls. No changes in serum corticosteroids were observed with TF5 injection of controls, but there was a significant decrease in the corticosteroid levels of the severely malnourished with TF5 injection. Cytoxicity assays of T cell function, antibody dependent cellular cytoxicity and cytoxicity to mouse thymona tumor cells, in mice fed moderately protein deficient diets showed suppression compared to controls fed 20% protein. TF5 injection partially and temporarily increased these functions in the malnourished mice.

Thymic peptide hormones: basic properties and clinical applications in cancer

The manuscript will provide an in-depth and critical review of the nomenclature, biochemistry, biological properties, and a summary of published and on-going clinical trials with all reported thymic preparations, including both partially purified thymic factors (e.g., thymosin fraction 5, thymostimulin) as well as purified and synthesized thymic peptides (e.g., thymosin alpha 1, thymulin). Particular emphasis will be placed on which thymic peptides should be categorized as true hormones. In addition, the comparative biochemistry and biological activity in animals will be summarized and contrasted for all the currently available thymic factors. The effects, in vitro of thymic factors, on peripheral blood lymphocytes isolated from normal donors and patients with primary immunodeficiency disorders, autoimmune disorders, and neoplastic disorders will also be reviewed. Finally, a detailed critical summary of the clinical trials performed with each of the thymic preparations will be presented with an emphasis on treatment of patients with cancer.

Bone marrow transplantation--an expanding approach to treatment of many diseases

Thus, we can conclude that marrow transplantation has already influenced medical practice greatly. It has offered a treatment which often cures patients of more than 20 otherwise lethal diseases. The treatment so horrendously difficult and dangerous at first has already been greatly improved, simplified, and made much safer. The availability of a suitable donor has been much extended and real progress has been made in prevention and perhaps even in treatment of graft-versus-host disease. This has made possible the option of marrow transplantation for every patient in whom we think the treatment may be beneficial. The problem underlying many cases of interstitial pneumonia has been identified and patients are already benefitting clinically from this progress. Progress has also been made which promises antiviral therapy which could reduce, prevent, and ultimately eliminate the intercurrent virus infections which limit the applicability of marrow transplantation, especially for children with severe immunodeficiencies. I do not know how far this line of investigation can be taken. However, just as we have learned stepwise to use marrow transplants from matched siblings to treat many diseases, to use fetal liver in place of bone marrow, to employ matched relative donors when a matched sibling is not available, and, finally, even to use parental donors to achieve correction of SCID, we now have good reason to believe that, ultimately, we can use marrow transplantation without fear of GVHD to address many additional genetically determined and acquired diseases; certainly, for those diseases that involve any of the cells that are derived from bone marrow cells, and perhaps for those attributable even to cells of other organs and tissues, the functions of which are, in whole or in part, a consequence of interactions of marrow-derived cells and cells of ectodermal or endodermal origin, marrow transplantation may be useful. To us, the future of marrow transplantation as a major modality of treatment or prevention of many diseases, including hemoglobinopathesis, immunodeficiencies, hematologic abnormalities, abnormalities of function of marrow-derived cells, and even inborn errors of function of cells of organs and tissues not of marrow origin, seems bright, indeed. Further, with the capacity to introduce resistance genes against viruses and malignancies, autoimmune diseases, and diseases dependent on anomalies of immune response genes, marrow transplantation for many other diseases seems a more remote possibility.(ABSTRACT TRUNCATED AT 400 WORDS)

Radioimmunoassays for the thymic hormone serum thymic factor (FTS)

Four radioimmunoassays (RIA) are described for the quantitation of serum thymic factor (facteur thymique serique, FTS), a thymic peptide hormone. Each assay employs an antibody specific for FTS, synthetic FTS (Glp-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn) as the hormone standard, and a radioiodinated FTS analogue as the tracer. Since FTS lacks a tyrosine residue, 2 FTS analogues were synthesized by the solid-phase method with tyrosyl-alanyl or 3-(2,6-dichlorobenzyl)tyrosyl-alanyl in place of the amino-terminal pyroglutamyl residue (Glp). They showed full FTS immunoreactivity and their radioiodinated derivatives served as FTS tracers. Two assays used the antiserum from a rabbit immunized with an FTS-protein conjugate. Two other assays used a monoclonal antibody against FTS produced by a hybridoma derived from mouse myeloma cells and splenocytes from a BALB/c mouse immunized with an FTS-mouse IgG conjugate (Ohga et al., 1982). All 4 RIAs were specific for FTS. The more sensitive rabbit antiserum can detect as little as 1 pg of FTS in a 50 microliters sample, which may allow quantitation of the FTS circulating in human peripheral blood.

Activity of synthetic thymosin alpha 1 C-terminal peptides in the azathioprine E-rosette inhibition assay

The helical C-terminal portion of the thymic hormone thymosin alpha 1 exhibits immunological activities in several in vitro assays. The C-terminal region spanning positions 17-28 was subdivided into 11 overlapping peptide segments to collect further information on the molecular signal hypothesis for T lymphocyte differentiation by thymosin alpha 1 derived peptides. All peptides were synthesized by classical means and tested in the azathioprine E-rosette inhibition assay. The results provided additional evidence that a basic-acidic-lipophilic sequence character is a possibly essential feature of a molecular signal for T cell differentiation. Five to seven structures beginning N terminally with lysine fitted this functional key. They showed immunological in vitro activities similar to and even better than the parent hormone thymosin alpha 1 in the ability to express in immature spleen cells from adult thymectomized mice the E-receptor sensitive to azathioprine inhibition.

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.