In-utero coxsackievirus B4 infection of the mouse thymus.

Type B coxsackievirus (CV-B) infections are involved frequently in the triggering of several autoimmune diseases such as myocarditis, dilated cardiomyopathy, pericarditis, pancreatitis, type 1 diabetes, encephalitis, thyroiditis or Sjögren's syndrome. Serological and virological evidence suggests that maternal infections during pregnancy can play a role in the appearance of these diseases in offspring. The current study aims to explore the effect of an in-utero CV-B infection on the fetal thymus, the central site for programming immunological self-tolerance. In this perspective, female Swiss albino mice were inoculated intraperitoneally or orally with the diabetogenic CV-B4 E2 strain at gestational days 10 or 17. Offspring were killed at different post-inoculation times, and their thymuses were analysed for evidence of infection and alterations in thymic T cell subsets. In-utero CV-B infection of the thymus was demonstrated during the course of vertical transmission, as attested by viral RNA and infectious virus detection in most analysed samples. No histopathological changes were evident. Thymic T cells were not depleted, despite being positive for viral RNA. As evidenced by flow cytometry analysis, CV-B infection of the fetal thymus induced significant changes of thymic T cell populations, particularly with maternal inoculation at gestational day 10. Altogether, these findings suggest that CV-B infection of the fetal thymus may play an important role in the genesis of autoimmune diseases.

Additional intranasal oxytocin to escitalopram improves depressive symptoms in resistant depression: an open trial.

The aim of this open trial was to assess the antidepressant/anxiolytic effects of oxytocin used as an adjunct to antidepressant in treatment-resistant depression. Fourteen patients, who have not responded to 40mg of escitalopram, received intranasal synthetic oxytocin during 4 weeks, in association with antidepressant. This is the first open trial study suggesting OT in association with escitalopram significantly reduced scores on Hamilton Depression Rating Scale.

El síndrome tirogástrico autoinmune: sus efectos sobre los micronutrientes y la tumorigénesis gástrica / The Thyrogastric Autoimmune Syndrome: Its Effects on Micronutrients and Gastric Tumorigenesis

El síndrome autoinmune tirogástrico (SAT) fue descrito en pacientes en quienes el suero presentaba reacciones cruzadas de anticuerpos dirigidos contra los antígenos de células parietales gástricas y tiroideas. A través de dos casos describimos el espectro patológico de este síndrome. El primero asocia una tiroiditis de Hashimoto y una anemia perniciosa, desarrollando durante el seguimiento un tumor neuroendocrino gástrico. El segundo caso presenta una enfermedad de Graves y una gastritis autoinmune, secundaria a Helicobacter Pylori: esta última es reversible luego de tratamiento. Se considera que la poliendocrinopatía autoinmune de tipo III (dentro de la cual puede inscribirse el síndrome tirogástrico) es rara, pero no lo es en nuestra experiencia. Un total de 13 % (32/240) de los pacientes con tiroiditis que hemos seguido prospectivamente, tienen también una gastritis autoinmune. Helicobacter pylori está claramente implicado en el 16 % de estos casos con gastritis autoinmune. Infección, malabsorción y gastritis son potencialmente reversibles después del tratamiento de erradicación bacteriana. En el 84 % restante de los pacientes con gastritis y tiroiditis, no se encuentran pruebas serológicas o histológicas de Helicobacter pylori. La autoinmunidad gástrica es entonces irreversible, y conduce a una hipergastrinemia, hipoclorhidria y atrofia gástrica severa. La hipergastrinemia estimula la hiperplasia de las células enterocromafines, con riesgo de progresión a un tumor neuroendocrino. Proponemos un esquema diagnóstico novedoso para mejor caracterización del síndrome tirogástrico. Exponemos la literatura sobre el tema y discutimos a partir de algunos modelos animales pertinentes sobre la autoinmunidad gástrica infecciosa. Rev Argent Endocrinol Metab 51:37-43, 2014 Los autores declaran no poseer conflictos de interés.

The thyrogastric autoimmune syndrome (TAS) was described in patients in whom the serum cross-reacted both with gastric parietal cells antigens and thyroid antigens. We report two cases illustrating the spectrum of pathological features of TAS. The first one is a case of Hashimoto’s Thyroiditis associated with pernicious anemia, further developing a gastric neuroendocrine tumor during follow up. The second one is a case of Graves’ disease and autoimmune reversible gastritis, While type III autoimmune polyendocrinopathy (which includes TAS) is considered to be rare, this was not the case in our experience. A total of 13 % (32/240) of the patients with thyroiditis that we have prospectively followed have also autoimmune gastritis. Helicobacter pylori is clearly implicated in 16 % of the cases of autoimmune gastritis. Infection, malabsorption and gastritis are potentially reversible after bacterial eradication treatment. In the remaining 84 % of patients with gastritis, no histological or serological evidence of Helicobacter pyloriwas found. Gastric autoimmunity is then irreversible, leading to gastric severe atrophy, hypochlorhydria and hypergastrinemia. Hypergastrinemia stimulates enterochromaffin cell hyperplasia, progressing eventually to neuroendocrine tumors. We propose a diagnostic approach to improve the characterization of TAS, including a literature review and discussing some relevant animal models of infectious gastric autoimmunity. Rev Argent Endocrinol Metab 51:37-43, 2014 No financial conflicts of interest exists.

[The thyrogastric syndrome: its effects on micronutriments and gastric tumorigenesis]. / Le syndrome auto-immun thyro-gastrique: ses effets sur les micronutriments et la tumorigenèse gastrique.

The thyrogastric autoimmune syndrome (TAS) was described in patients in whom the serum cross-reacted both with gastric parietal cells antigens and thyroid antigens. We report two cases illustrating the spectrum of pathogical features of TAS. The first case associates Hashimoto's thyroiditis and anemia perniciosa,and develops a gastric neuroendocrine tumor during follow up. The second case presents with a Graves' disease and an autoimmune reversible gastritis, secondary to Helicobacter pylori. Whereas type III autoimmune polyendocrinopathy is rare, TAS is frequent in our experience. Some 13% (32/240) of patients that we have prospectively followed affected with thyroiditis have also autoimmune gastritis. Helicobacter pylori is clearly implicated in 16% of autoimmune gastritis cases. Infection, malabsorption and gastritis are potentially reversible after bacterial eradication treatment. In the other 84% of gastritis patients, no histological or serological proof of Helicobacter pylori is found. Gastric autoimmunity is then irreversible, leading to gastric severe atrophy, hypochlorhydria and hypergastrinemia. Hypergastrinemia stimulates enterochromaffin cell hyperplasia, possibly progressing to neuroendocrine tumors. We propose a diagnostic approach to improve the characterization of TAS. We review the literature on the subject and discuss some interesting animal models of infectious gastric autoimmunity.

The appearance of the thymus and the integrated evolution of adaptive immune and neuroendocrine systems.

The immune system may be considered as a sensory organ able to respond to different kinds of danger signals that are not detected by nervous cells. The immune response is not autonomous but also regulated by the central and peripheral nervous system, as well as by neuropeptides, vitamin D and neuroendocrine axes such as the corticotrope, somatotrope, thyrotrope and gonadotrope axes. During evolution, the thymus emerged concomitantly with recombinase-dependent adaptive immunity as an'immune brain' or a'master class' highly specialized in the orchestration of central immunological self-tolerance. This was an absolute requirement for survival of species because of the high risk of autotoxicity inherent to the stochastic generation of extreme diversity characterizing this novel adaptive type of immune defenses against non-self. The thymus now appears to be an obligatory intersection for the integrated evolution of the major systems of cell-to-cell signalling, the nervous, endocrine and immune systems. The presentation of many self-peptides by thymic major histocompatibility complex (MHC) proteins is controlled by the autoimmune regulator (AIRE) gene/protein and is responsible for the clonal deletion of self-reactive T cells. In the same time, by still unexplained mechanisms, MHC presentation of the same self-peptides in the thymus promotes the generation of self-specific FOXP3+ CD4+CD25+ natural regulatory T cells (nTreg) that are able to inhibit in periphery self-reactive CD4+ and CD8+ T cells having escaped the thymus censorship. Moreover, a thymus dysfunction is more and more established as the primary event driving the development of organ-specific autoimmunity, which is the tribute paid, mainly by mankind, for the preservation of self against non-self. Our novel knowledge about thymus physiology and physiopathology already serves as the basis for the development of various innovative and efficient immunomodulating strategies in pharmacology.

Immunology in the clinic review series; focus on type 1 diabetes and viruses: enterovirus, thymus and type 1 diabetes pathogenesis.

Thymus dysfunction, especially immune suppression, is frequently associated with various virus infections. Whether viruses may disturb the thymus function and play a role in the pathogenesis of autoimmune diseases is an open issue. Enteroviruses, especially Coxsackievirus B4 (CV-B4), have been largely suggested as potential inducers or aggravating factors of type 1 diabetes (T1D) pathogenesis in genetically predisposed individuals. Several pathogenic mechanisms of enterovirus-induced T1D have been suggested. One of these mechanisms is the impairment of central self-tolerance due to viral infections. Coxsackievirus-B4 is able to infect murine thymus in vitro and in vivo and to infect human thymus in vitro. Thymic epithelial cells and thymocytes are targets of infection with this virus, and several abnormalities, especially disturbance of maturation/differentiation processes, were observed. Altogether, these data suggest that CV-B infection of thymus may be involved in the pathogenesis of T1D. Further investigations are needed to explore this hypothesis.

[The endocrine effects of smoking]. / Le tabac et ses effets sur le système endocrinien.

Almost one third of men and women smoke in Belgium. Besides the well known tobacco's neck and cardiopulmonary systems adverse effects as well as associated neoplasms, today we recognize other deleterious consequences of tobacco on the neuroendocrine, thyroid and reproductive systems. Not only active smokers but also the fetus carried by a smoking mother is at risk for important health problems. Tobacco is a recognized risk factor of occurrence of ophtalmopathy. Some of the active components of tobacco as the thiocyanates are goitrogenic. Tobacco is a risk factor for men and women's infertility. Newborns from parents that smoke are at risk for sudden death. These consequences represent a major public health issue. A campaign for smoking cessation has been recently launched by the Federation of Public Health Service and the INAMI in Belgium.

Oxytocin: From milk ejection to maladaptation in stress response and psychiatric disorders. A psychoneuroendocrine perspective.

Oxytocin (OT) is implicated in stress reduction as well as in social behavior. It inhibits the stress-induced activity of the hypothalamic-pituitary adrenal axis responsiveness. OT is involved in social affiliation, sexual and maternal-infant binding, anxiety, mood, feeding control and memory. Several lines of evidence suggest a role of OT in psychiatric disorders. Various psychiatric disorders are strongly influenced by social variables, such as panic attacks, depression and early childhood autism, and seem to exhibit a particularly close connection with the brain dynamics that underlie social emotions. This paper proposes an overview of OT in psychiatric disorders through the links with the stress response and prosocial behavior.

[Immune recovery following allogeneic hematopoietic cell transplantation]. / Reconstitution du système immunitaire après allogreffe de cellules souches hématopoïétiques.

Allogeneic hematopoietic stem cell transplantation (alloHCT) is frequently used as treatment for patients with hematological malignancies. Its efficacy depends in part on the destruction of recipient tumor cells by donor immune cells contained in the graft (graft-versus-tumor effects), underlying the interest of studying donor immune recovery after alloHCT. Further, donor immune cells play an important role in the prevention and treatment of infections after alloHCT, and are the cause of graft-versus-host disease (GVHD). This article reviews the mechanisms of immune recovery after allogeneic hematopoietic cell transplantation (alloHCT), as well as techniques currently used to monitor immune function following alloHCT.

Dialogue between blastocyst hCG and endometrial LH/hCG receptor: which role in implantation?

The specific interaction of blastocyst-derived human chorionic gonadotropin (hCG) and endometrial LH/hCG-R constitutes a fundamental component of the molecular dialogue at the materno-fetal interface. From our observations and studies from other groups, hCG was indeed shown to play a significant role in implantation and tolerance of the embryo, decidual differentiation and remodeling, as well as in placentation. The profile pattern of LH/hCG-R expression by endometrial epithelium correlates with the theoretical timing of the implantation window. Studies are currently being conducted in assisted medical procreation and in an animal model of implantation to establish the index of LH/hCG-R expression as a new biomarker of uterine receptivity for embryo implantation.

[Clinical evaluation of thymic function]. / Evaluation clinique de la fonction du thymus.

The essential role of the thymus is to install an extremely diverse repertoire of T lymphocytes that are self-tolerant and competent against non-self, as well as to generate self-antigen specific regulatory T cells (Treg) able to inactivate in periphery self-reactive T cells having escaped the thymic censorship. Although indirect, techniques of medical imaging and phenotyping of peripheral T cells may help in the investigation of thymic function. Nowadays however, thymopoiesis is better evaluated through quantification by PCR of T-cell receptor excision circles (TREC) generated by intrathymic random recombination of the gene segments coding for the variable parts of the T-cell receptor for antigen (TCR). The TREC methodology is very valuable in the circumstances not associated with intense proliferation or apoptosis of peripheral T lymphocytes.

[Evaluation of thymopoiesis: clinical applications]. / Evaluation de la thymopoïèse: applications cliniques.

In the precedent article, we have described how T-cell generation in the thymus (thymopoiesis) may be currently evaluated through quantification by PCR of T-cell receptor excision circles (TREC) generated by intrathymic random recombination of the gene segments coding for variable parts of T-cell receptor for antigen (TCR). In hematology, TREC methodology helps in a better understanding of immune reconstitution after graft of hematopoietic stem cells: first there is a proliferation of mature T cells present in the graft, then a differentiation of naive T cells. In geriatrics, the homeostasis of the peripheral T-cell repertoire is maintained through proliferation of peripheral memory T cells rather than through thymic generation of naive T cells. In addition, TREC quantification constitutes a novel major tool for deciphering the tight control of thymopoiesis by the neuroendocrine system.

[What's new at the maternal-foetal interface: role of the hCG/LH-hCG receptor couple during embryo implantation]. / Du nouveau à l'interface materno-foetale: rô1e du couple hCG/récepteur LH-hCG dans l'implantation embryonnaire.

Implantation of the embryo into the maternal endometrium represents a unique biological process, combining an immunological (tolerance of an allograft) and biological (adhesion of two epitheliums) paradox. The success of implantation depends on a receptive endometrium, a functionally normal blastocyst and a synchronized cross-talk between embryonic and maternal tissues. Though sexual steroids control the process, a cascade of growth factors or cytokines are the prime paracrine mediators of the dialogue at the maternal-embryonic interface. HCG is one of the molecules most precociously produced by the embryo and is the most specific marker of its presence. HCG is a luteotropic factor which relays the inadequate support provided by the reduced rates of LH, but also influences the pregnancy on a paracrine mode by a local action on implantation process, probably by interacting with its receptor, the LH/hCG-R that we have evidenced on endometrial epithelium. We demonstrate that embryo actively participate into its implantation, tolerance and placentation.

[Role of the thymus in the physiopathology and in the prevention of type 1 diabetes]. / La voie du thymus dans la physiopathologie et la prévention du diabète de type 1.

There is now accumulating experimental evidence that, much more than a breakdown of peripheral immunological self-tolerance, the development of the diabetogenic autoimmune response (in type 1 diabetes) first results from a thymus dysfunction in the establishment of central beta-cell self-tolerance. Based on the homology between dominant thymic self-antigens and peripheral autoantigens, on the one hand, and the difference between the immune responses elicited by these antigens (respectively, tolerance vs immunity), a novel strategy is proposed for the development of a "negative" self-vaccine able to (re)install the state of immune self-tolerance to pancreatic islet beta cells and prevent type 1 diabetes.

[Importance of a thymus dysfunction in the pathophysiology of type 1 diabetes]. / Nouvelles données sur la pathogénie du diabète de type 1.

The autoimmune nature of the diabetogenic process and the major contribution of T lymphocytes stand now beyond any doubt. However, despite the identification of the three major type 1-diabetes-related autoantigens (insulin, GAD65 and phosphatase IA-2), the origin of this immune dysregulation still remains unknown. More and more evidence supports a thymic dysfunction in the establishment of central self-tolerance to the insulin family as a crucial factor in the development of the autoimmune response selective of pancreatic insulin-secreting islet beta cells. All the genes of the insulin family (INS, IGF1 and IGF2) are expressed in the thymus network. However, IGF-2 is the dominant member of this family first encountered by T cells in the thymus, and only IGFs control early T-cell differentiation. IGF2 transcription is defective in the thymus in one animal model of type 1 diabetes, the Bio-Breeding (BB) rat. The sequence B9-23, one dominant autoantigen of insulin, and the homologous sequence B11-25 derived from IGF-2 exibit the same affinity and fully compete for binding to DQ8, one class-II major histocompatibility complex (MHC-II) conferring major genetic susceptibility to type 1 diabetes. Compared to insulin B9-23, the presentation of IGF-2 B11-25 to peripheral mononuclear cells (PBMCs) isolated from type 1 diabetic DQ8+ adolescents elicits a regulatory/tolerogenic cytokine profile (*IL-10, *IL-10/IFN-g, *IL-4). Thus, administration of IGF-2 derived self-antigen(s) might constitute a novel form of vaccine/immunotherapy combining both an antagonism for the site of presentation of a susceptible MHC allele, as well as a downstream tolerogenic/regulatory immune response.

[Role of viral infections in the pathogenesis of type 1 diabetes]. / Le rôle des virus dans la pathogénie du diabète de type 1.

The precise role of viral infections in the pathogenesis of type 1 diabetes is still the subject of an important discussion. Coxsackievirus B4 (CVB4) is the virus the most implicated by a series of epidemiological studies. Pathogenic mechanisms underlying such a relationship implicate a molecular mimicry between CVB4 sequences and beta-cell autoantigens, but mainly a persistent CVB4 infection of pancreatic beta cells followed by a release of sequestered beta antigens and a "bystander" activation of autoreactive T cells. The demonstration of intrathymic expression of antigens specific of peripheral tissues has opened a novel research perspective. We have shown that CVB4 is able to infect in a persistent and producive manner human thymic epithelial cell cultures and human fetal thymic lobes in organotypic cultures. This infection induces an important thymic dysfunction characterized by a severe depletion of thymocytes (thymic T cells) and an up-regulated expression by thymic epithelial and T cells of class I proteins encoded by the major histocompatibility complex (MHC-I). Such thymic dysfunction might be responsible for a decrease of beta-cell central self-tolerance and anti-CVB4 cytotoxic CD8 T-cell activity. CVB4-induced thymic dysfunction would contribute in close association with the peripheral "bystander" effect to the destruction of insulin-secreting islet beta cells and to the development of type 1 diabetes.

Ontogenesis and functional aspects of oxytocin and vasopressin gene expression in the thymus network.

Ontogenesis of oxytocin (OT) and vasopressin (VP) gene expression and function were investigated in murine thymus. OT and VP transcripts were detected in the thymus on embryonic days 13 and 15, respectively. Corresponding messenger RNAs were evidenced in thymic epithelial cells by in situ hybridization with a neurophysin probe. From all OT and VP receptors, only OTR was expressed by all T-cell subsets, while V1bR was found in double positive and single positive CD8 cells. In fetal thymic organ cultures, OTR antagonist d[D-Tyr(Et)2, Thr4]OVT increased early apoptosis of CD8 cells, while V1bR antagonist (Sanofi SSR149415) inhibited T-cell differentiation, and favored CD8 T-cell commitment.

Oxytocin- and vasopressin-induced growth of human small-cell lung cancer is mediated by the mitogen-activated protein kinase pathway.

Malignant growth of small-cell lung carcinoma is promoted by various neuroendocrine autocrine/paracrine loops. Therefore, to interfere with this mitogenic process, it is crucial to elucidate the mechanisms involved. It is known that the oxytocin (OT) and vasopressin (VP) genes, normally transcriptionally restricted in their expression, are activated in small-cell lung cancer (SCLC), concomitantly with expression of their receptors (OTR, V1aR, V1bR/V3R and V2R). The aim of the present study was to characterize, in concentrations close to physiological and pharmacological conditions, intracellular signalling events triggered by OT and VP binding to their specific receptors in SCLC cells and to identify factors mediating OT- and VP-induced mitogenic effects on SCLC. Known agonists for OTR ([Thr4,Gly7]OT) and V1aR (F180), in addition to OT and VP, were able to elicit increases in cytosolic Ca2+ levels and this effect could be blocked using an OTR antagonist (OVTA) or a V1aR antagonist (SR49059) respectively. There was no activation of the cAMP pathway detected after VP, dDAVP (a V2R agonist), or OT treatment. Stimulation of SCLC cells with OT and VP led to an increase of extracellular signal-regulated kinase (ERK) 1/2 phosphorylation, maximal at 5 min, and the subsequent phosphorylation of its downstream target p90 ribosomal S6 kinase (p90RSK). Pre-incubation with OVTA and SR49059, and with inhibitors of phospholipase C (PLC), protein kinase C (PKC), mitogen-activated protein kinase/ERK kinase (MEK) 1/2 and a Ca2+ chelator significantly reduced OT- and VP-induced ERK1/2 phosphorylations. OVTA, SR49059 as well as MEK1/2 and PKC inhibitors also downregulated OT- and VP-induced p90RSK phosphorylation. In [3H]thymidine-uptake experiments, we subsequently observed that PLC, Ca2+, PKC and ERK1/2 are absolutely required for the OT- and VP-stimulated SCLC cellular growth process. In conclusion, the results presented here indicate that OT- and VP-induced mitogenic effects on SCLC are respectively mediated by OTR and V1aR signalling and that this mitogenic signalling passes through the phosphorylation of ERK1/2 and p90RSK in a PLC-, Ca2+-, PKC- and MEK1/2-dependent pathway.

Human chorionic gonadotropin and growth factors at the embryonic-endometrial interface control leukemia inhibitory factor (LIF) and interleukin 6 (IL-6) secretion by human endometrial epithelium.

BACKGROUND: The elucidation of the molecular mechanisms by which the embryo contributes to its implantation is an area of extensive research. The main objective of this study was to investigate the pattern of leukemia inhibitory factor (LIF) and interleukin-6 (IL-6) secretion by human endometrial epithelium, and their regulation by human chorionic gonadotropin (hCG) and other growth factors present at the embryonic-endometrial interface. METHODS: Endometrial epithelial cells (EEC) were isolated from biopsies collected at both proliferative and secretory phases of fertile women. RESULTS: HCG (1-50 IU/ml) increased LIF secretion by EEC cultures derived from follicular phase (up to 285+/-75%) or from secretory phase (up to 212+/-16%). In contrast, hCG reduced IL-6 secretion by EEC in both phases. The hCG/LH receptor gene was transcribed by EEC as evidenced by RT-PCR. Insulin-like growth factors 1 and 2 increased LIF secretion by EEC. Transforming growth factor beta1 stimulated LIF and reduced IL-6 secretion. CONCLUSIONS: Through hCG, the blastocyst may be involved in the control of its implantation (via an increase of proimplantatory LIF) and tolerance (via an inhibition of proinflammatory IL-6). Other growth factors present at the embryonic-endometrial interface are also involved in the control of LIF and IL-6 endometrial secretion.