Type I interferon mediated induction of somatostatin leads to suppression of ghrelin and appetite thereby promoting viral immunity in mice.

Loss of appetite (anorexia) is a typical behavioral response to infectious diseases that often reduces body weight. Also, anorexia can be observed in cancer and trauma patients, causing poor quality of life and reduced prospects of positive therapeutic outcomes. Although anorexia is an acute symptom, its initiation and endocrine regulation during antiviral immune responses are poorly understood. During viral infections, plasmacytoid dendritic cells (pDCs) produce abundant type I interferon (IFN-I) to initiate first-line defense mechanisms. Here, by targeted ablation of pDCs and various in vitro and in vivo mouse models of viral infection and inflammation, we identified that IFN-I is a significant driver of somatostatin (SST). Consequently, SST suppressed the hunger hormone ghrelin that led to severe metabolic changes, anorexia, and rapid body weight loss. Furthermore, during vaccination with Modified Vaccinia Ankara virus (MVA), the SST-mediated suppression of ghrelin was critical to viral immune response, as ghrelin restrained the production of early cytokines by natural killer (NK) cells and pDCs, and impaired the clonal expansion of CD8+ T cells. Thus, the hormonal modulation of ghrelin through SST and the cytokine IFN-I is fundamental for optimal antiviral immunity, which comes at the expense of calorie intake.

GHRH-SST-GH-IGF axis regulates crosstalk between growth and immunity in rainbow trout (Oncorhynchus mykiss) infected with Vibrio anguillarum.

An energy trade-off is existed between immunological competence and growth. The axis of growth hormone releasing hormone, somatostatin, growth hormone, insulin-like growth factor (GHRH-SST-GH-IGF axis) regulates growth performances and immune competences in rainbow trout (Oncorhynchus mykiss). The salmonid-specific whole genome duplication event is known to result in duplicated copies of several key genes in GHRH-SST-GH-IGF axis. In this study, we evaluated the physiological functions of GHRH-SST-GH-IGF axis in regulating crosstalk between growth and immunity. Based on principal components analysis (PCA), we observed the overall expression profiles of GHRH-SST-GH-IGF axis were significantly altered by Vibrio anguillarum infection. Trout challenged with Vibrio anguillarum showed down-regulated igf1s subtypes and up-regulated igfbp1a1. The brain sst genes (sst1a, sst1b, sst3b and sst5) and igfpbs genes (igfbp4s and igfbp5b2) were significantly affected by V. anguillarum infection, while the igfbp4s, igfbp5s, igfbp6s and igf2bps genes showed significant changes in peripheral immune tissues in response to V. anguillarum infection. Gene enrichment analyses showed functional and signaling pathways associated with apoptosis (such as p53, HIF-1 or FoxO signaling) were activated. We further proposed a possible model that describes the IGF and IGFBPs-regulated interaction between cell growth and programmed death. Our study provided new insights into the physiological functions and potentially regulatory mechanisms of the GHRH-SST-GH-IGF axis, indicating the pleiotropic effects of GHRH-SST-GH-IGF axis in regulating crosstalk between growth and immunity in trout.

Thyrotropin-Releasing Hormone (TRH) and Somatostatin (SST), but not Growth Hormone-Releasing Hormone (GHRH) nor Ghrelin (GHRL), Regulate Expression and Release of Immune Growth Hormone (GH) from Chicken Bursal B-Lymphocyte Cultures.

It is known that growth hormone (GH) is expressed in immune cells, where it exerts immunomodulatory effects. However, the mechanisms of expression and release of GH in the immune system remain unclear. We analyzed the effect of growth hormone-releasing hormone (GHRH), thyrotropin-releasing hormone (TRH), ghrelin (GHRL), and somatostatin (SST) upon GH mRNA expression, intracellular and released GH, Ser133-phosphorylation of CREB (pCREBS133), intracellular Ca2+ levels, as well as B-cell activating factor (BAFF) mRNA expression in bursal B-lymphocytes (BBLs) cell cultures since several GH secretagogues, as well as their corresponding receptors (-R), are expressed in B-lymphocytes of several species. The expression of TRH/TRH-R, ghrelin/GHS-R1a, and SST/SST-Rs (Subtypes 1 to 5) was observed in BBLs by RT-PCR and immunocytochemistry (ICC), whereas GHRH/GHRH-R were absent in these cells. We found that TRH treatment significantly increased local GH mRNA expression and CREB phosphorylation. Conversely, SST decreased GH mRNA expression. Additionally, when added together, SST prevented TRH-induced GH mRNA expression, but no changes were observed in pCREBS133 levels. Furthermore, TRH stimulated GH release to the culture media, while SST increased the intracellular content of this hormone. Interestingly, SST inhibited TRH-induced GH release in a dose-dependent manner. The coaddition of TRH and SST decreased the intracellular content of GH. After 10 min. of incubation with either TRH or SST, the intracellular calcium levels significantly decreased, but they were increased at 60 min. However, the combined treatment with both peptides maintained the Ca2+ levels reduced up to 60-min. of incubation. On the other hand, BAFF cytokine mRNA expression was significantly increased by TRH administration. Altogether, our results suggest that TRH and SST are implicated in the regulation of GH expression and release in BBL cultures, which also involve changes in pCREBS133 and intracellular Ca2+ concentration. It is likely that TRH, SST, and GH exert autocrine/paracrine immunomodulatory actions and participate in the maturation of chicken BBLs.

Gold nanoparticle amplification strategies for multiplex SPRi-based immunosensing of human pancreatic islet hormones.

In this work, we demonstrate the potential use of SPRi for secretion-monitoring of pancreatic islets, small micro-organs that regulate glucose homeostasis in the body. In the islets, somatostatin works as a paracrine inhibitor of insulin and glucagon secretion. However, this inhibitory effect is lost in diabetic individuals and little is known about its contribution to the pathology of diabetes. Thus, the simultaneous detection of insulin, glucagon and somatostatin could help understand such communications. Previously, the authors introduced an SPRi biosensor to simultaneously monitor insulin, glucagon and somatostatin using an indirect competitive immunoassay. However, our sensor achieved a relatively high LOD for somatostatin detection (246 nM), the smallest of the three hormones. For this reason, the present work aimed to improve the performance of our SPRi biosensor using gold nanoparticles (GNPs) as a means of ensuring somatostatin detection from a small group of islets. Although GNP amplification is frequently reported in the literature for individual detection of analytes using SPR, studies regarding the optimal strategy in a multiplexed SPR setup are missing. Therefore, with the aim of finding the optimal GNP amplification strategies for multiplex sensing we compared three architectures: (1) GNPs immobilized on the sensor surface, (2) GNPs conjugated with primary antibodies (GNP-Ab1) and (3) GNPs conjugated with a secondary antibody (GNP-Ab2). Among these strategies an immunoassay using GNP-Ab2 conjugates was able to achieve multiplex detection of the three hormones without cross-reactivity and with 9-fold LOD improvement for insulin, 10-fold for glucagon and 200-fold for somatostatin when compared to the SPRi biosensor without GNPs. The present work denotes the first report of the simultaneous detection of such hormones with a sensitivity level comparable to ELISA assays, particularly for somatostatin.

Localization of amylin-like immunoreactivity in the striped velvet gecko pancreas.

Immunohistochemical techniques were employed to investigate the distribution of amylin-like immunoreactive cells in the pancreas of gecko Homopholis fasciata. Four types of endocrine cells were distinguished: insulin immunoreactive (B cells), pancreatic polypeptide immunoreactive (PP cells), glucagon and pancreatic polypeptide immunoreactive (A/PP cells) and somatostatin immunoreactive cells (D cells). Pancreatic islets contained B, A/PP and D cells, whereas extrainsular regions contained B, D and PP cells. In the pancreatic islets, amylin-like immunoreactive cells corresponded to B cells, but not to A/PP or D cells. In the extrainsular regions, amylin-like immunoreactive cells corresponded to either B or PP cells. Amylin secreted from intrainsular B cells may regulate pancreatic hormone secretion in an autocrine and/or a paracrine fashion. On the other hand, amylin secreted from extrainsular PP and B cells, and/or intrainsular B cells may participate in the modulation of calcium homoeostasis in an endocrine fashion.

Multiplex Surface Plasmon Resonance Imaging-Based Biosensor for Human Pancreatic Islets Hormones Quantification.

Diabetes arises from secretory defects in vascularized micro-organs known as the islets of Langerhans. Recent studies indicated that furthering our understanding of the paracrine effect of somatostatin on glucose-induced insulin secretion could represent a novel therapeutic avenue for diabetes. While many research groups are interested in insulin and glucagon secretion, few are particularly focused on studying the paracrine interaction in islets' cells, and none on monitoring a secretory fingerprint that contemplates more than two hormones. Surface plasmon resonance imaging can achieve high-throughput and multiplexed biomolecule quantification, making it an ideal candidate for detection of multiple islet's secretion products if arrays of hormones can be properly implemented on the sensing surface. In this study, we introduced a multiplex surface plasmon resonance imaging-based biosensor for simultaneous quantification of insulin, glucagon, and somatostatin. Performing this multiplex biosensing of hormones was mainly the result of the design of an antifouling sensing surface comprised by a mixed self-assembly monolayer of CH3O-PEG-SH and 16-mercaptohexadecanoic acid, which allowed it to operate in a complex matrix such as an islet secretome. The limit of detection in multiplex mode was 1 nM for insulin, 4 nM for glucagon, and 246 nM for somatostatin with a total analysis time of 21 min per point, making our approach the first reporting a label-free and multiplex measurement of such a combination of human hormones. This biosensor holds the promise of providing us with a mean for the further understanding of the paracrine effect of somatostatin on glucose-induced insulin secretion and consequently help develop novel therapeutic agents for diabetes.

Changes in Somatostatin-Like Immunoreactivity in the Sympathetic Neurons Projecting to the Prepyloric Area of the Porcine Stomach Induced by Selected Pathological Conditions.

The aim of the present study was to define changes in the expression of somatostatin (SOM) in the sympathetic perikarya innervating the porcine stomach prepyloric area during acetylsalicylic-acid-induced gastritis (ASA) and experimentally induced hyperacidity (HCL) and following partial stomach resection (RES). On day 1, the stomachs were injected with neuronal retrograde tracer Fast Blue (FB). Animals in the ASA group were given acetylsalicylic acid orally for 21 days. On the 22nd day after FB injection, partial stomach resection was performed in RES animals. On day 23, HCL animals were intragastrically given 5 ml/kg of body weight of a 0.25 M aqueous solution of hydrochloric acid. On day 28, all pigs were euthanized. Then, 14-µm thick cryostat sections of the coeliac-superior mesenteric ganglion (CSMG) complexes were processed for routine double-labelling immunofluorescence. All pathological conditions studied resulted in upregulation of SOM-like (SOM-LI) immunoreactivity (from 14.97 ± 1.57% in control group to 33.72 ± 4.39% in the ASA group, to 39.02 ± 3.65% in the RES group, and to 29.63 ± 0.85% in the HCL group). The present studies showed that altered expression of SOM occurs in sympathetic neurons supplying the prepyloric area of the porcine stomach during adaptation to various pathological insults.

Gastrointestinal neuroendocrine peptides/amines in inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a chronic recurrent condition whose etiology is unknown, and it includes ulcerative colitis, Crohn's disease, and microscopic colitis. These three diseases differ in clinical manifestations, courses, and prognoses. IBD reduces the patients' quality of life and is an economic burden to both the patients and society. Interactions between the gastrointestinal (GI) neuroendocrine peptides/amines (NEPA) and the immune system are believed to play an important role in the pathophysiology of IBD. Moreover, the interaction between GI NEPA and intestinal microbiota appears to play also a pivotal role in the pathophysiology of IBD. This review summarizes the available data on GI NEPA in IBD, and speculates on their possible role in the pathophysiology and the potential use of this information when developing treatments. GI NEPA serotonin, the neuropeptide Y family, and substance P are proinflammatory, while the chromogranin/secretogranin family, vasoactive intestinal peptide, somatostatin, and ghrelin are anti-inflammatory. Several innate and adaptive immune cells express these NEPA and/or have receptors to them. The GI NEPA are affected in patients with IBD and in animal models of human IBD. The GI NEPA are potentially useful for the diagnosis and follow-up of the activity of IBD, and are candidate targets for treatments of this disease.

Efficacy and safety of an oral somatostatin DNA vaccine without antibiotic resistance gene in promoting growth of piglets.

This study aimed to evaluate the efficacy and safety of an oral DNA vaccine against somatostatin (SS) (pGS/2SS-asd, encoding two copies of somatostatin genes) mediated by attenuated Salmonella choleraesuis C500 without antibiotic resistance gene on piglets growth. A total of 50 piglets were uniformly divided into five groups. The animals in the first three groups were orally given vaccine in dose of either 5 9 1010, 5 9 109 or 5 9 108 colony-forming units (CFU).The remaining two groups were orally administered with either bacteria C500(containing pVAX-asd plasmid without somatostatin gene) or phosphate buffered saline (PBS) as controls. The results indicated that the vaccine induced SS-specific antibodies in a dose-dependent pattern. Compared with the PBS control, animals in the high-dose group showed lower SS levels and higher growth hormone (GH) levels in sera. Average daily gain of animals in the high dose group was increased by 32.88% and 26.46% during 4 and 8 weeks,respectively. Anti-SS antibodies were positively correlated with either GH levels or average daily gain at week 8 after primary immunization (P < 0.05). Faecal,soil and water samples originating from immunized piglets and surrounding environment were collected. The target gene (the fusion gene GS/2SS) of C500(pGS/2SS-asd) was not detected by PCR amplification in these samples,indicating that the surrounding environment was not contaminated by residual recombinant bacteria. In conclusion, the vaccine without antibiotic resistance gene is attributable to improve growth performance of piglets through an influence on GH secretion. Moreover, the immunization did not contaminate the surrounding environment of animals.

Evaluation of efficacy, biodistribution and safety of antibiotic-free plasmid encoding somatostatin genes delivered by attenuated Salmonella enterica serovar Choleraesuis.

We describe here a balanced-lethal system using an Asd(+) expression plasmid pVGS/2SS-asd encoding two copies of somatostatin (SS) genes carried by Δasd/Δcrp double mutant Salmonella enterica serovar Choleraesuis (named C501). The advantage of this novel system is the use of asd (aspartate-semialdehyde dehydrogenase) gene as selection marker to replace the antibiotic resistance markers, thus eliminating the industrial cultivation and environmental problems. We then evaluated the efficacy, biodistribution and safety of antibiotic-free plasmid delivered by strains C501. Mice orally immunized with C501 (pVGS/2SS-asd) had significantly higher levels of anti-SS total IgG and IgA antibodies than control mice and demonstrated a bias toward Th2-associated responses (IgG1/IgG2a ratio>1). Safety evaluation indicated that vaccinated mice displayed no abnormal clinical signs and histological changes. Biodistribution result revealed that the GS/2SS message was detected in several examined tissues with the exception of ovary and brain, but was rapidly cleared from the body (approximately 10 days). Furthermore, the risk of integration of plasmid pVGS/2SS-asd into the host cellular genome was considered to be negligible. These results may have important implications for the use of vaccine strain C501 (pVGS/2SS-asd) in domestic animals and prompt new perspectives on the safety of DNA vaccines delivered by attenuated bacteria.

Construction and immunogenicity of recombinant porcine circovirus-like particles displaying somatostatin.

In order to obtain a virus-like particles (VLPs) vaccine both for porcine circovirus type 2 (PCV2) prevention and growth-promotion, somatostatin (SS) gene was fused to the 3'-terminal of ORF2 gene of PCV2 with PCR, and a recombinant baculovirus (rAc-Cap-SS) was constructed. The expression of fusion protein Cap-SS (rCap-SS) with molecular weight of approximately 32kDa was identified by Western blot and indirect immunofluorescence assay in Sf9 cells. The self-assembled VLPs were observed under electron microscopy, which being morphologically similar to the recombinant Cap protein (rCap) expressed in the same baculovirus expressing system. Ninety four-week-old mice were immunized with the recombinant proteins twice. The results showed that mice immunized with rCap-SS protein developed antibody against Cap, which levels being similar to those immunized with rCap protein. The body weight gain and anti-SS antibody in rCap-SS group was higher than those of rCap and negative control groups during 28 and 42 days post inoculation (dpi). Furthermore, twenty 28-day-old piglets were vaccinated twice subcutaneously with the recombinant proteins. The results indicated that PCV2-specific antibody could be induced after vaccination with rCap-SS or rCap protein. Anti-SS antibody could be induced after rCap-SS vaccination and was higher than other groups at 14 and 28 dpi. The level of somatostatin concentration in the blood of pigs in rCap-SS group was significantly decreased at 14 dpi than other groups (P<0.05). The relative daily weight gain (RDWG) of pigs in rCap-SS group was obviously higher than that in other groups at 28 dpi. After challenge with PCV2, pigs in the vaccinated groups had no clearly clinical signs, and the RDWG was significantly higher than that in the challenge control group (CC) (P<0.05). The pathological lesions, viremia and viral load presented in the vaccinated groups were milder than those in challenge control group. It suggested that the recombinant porcine circovirus-like particles displaying somatostatin might be a novel subunit vaccine candidate for preventing PMWS and promoting pig growth.

Effect of immunization with a recombinant cholera toxin B subunit/somatostatin fusion protein on immune response and growth hormone levels in mice.

Somatostatin (SS) is a hormone that inhibits growth hormone secretion. Cholera toxin B subunit (CTB) is a widely used adjuvant to improve the immunogenicity of co-administrated antigen. To block the growth hormone-inhibiting effect of SS, a fusion gene of CTB and SS was constructed and expressed in Escherichia coli. The purified CTB/SS fusion protein polymerized into a biologically active pentamer required for CTB binding to the GM1 ganglioside receptor. Immunization with the CTB/SS protein induced specific immunity against CTB and SS in mice. The serum growth hormone of the CTB/SS-treated mice increased by 29 % (P < 0.05) compared with the control. The results indicated that the CTB/SS fusion protein was effective in inducing immune response against SS as well as elevating the growth hormone level.

Serotonin- and somatostatin-positive goblet cell carcinoid of the duodenum.

In the duodenum, mixed exocrine-endocrine tumors exhibiting both neuroendocrine and glandular differentiations [cf. appendiceal goblet cell carcinoids (GCCs)] are rare. We present a Japanese case with a duodenal GCC that was found during pathologic examination of a gastrectomy specimen removed for gastric mucosal cancer. The tumor was widely distributed within both the first portion of the duodenum and the gastric antrum, although mucosal involvement was observed only in the duodenum. The tumor cells formed solid nests, trabeculae, or tubules, and some displayed a goblet cell appearance. They were immunoreactive against antibodies for both serotonin and somatostatin, and showed an argentaffin reaction (similar to a "midgut" enterochromaffin cell carcinoid). Ultra-structurally, the tumor cells had an amphicrine nature. Physicians encounter GCC in the duodenum only rarely, and its discovery may be incidental. Its diagnosis will be challenging and will require careful clinical and pathologic examinations.

Innate immune properties of selected human neuropeptides against Moraxella catarrhalis and nontypeable Haemophilus influenzae.

BACKGROUND: Considerable evidence supports the concept of active communication between the nervous and immune systems. One class of such communicators are the neuropeptides (NPs). Recent reports have highlighted the antimicrobial activity of neuropeptides, placing them among the integral components of innate immune defense. This study examined the action of four human neuropeptides: calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY), substance P (SP) and somatostatin (SOM), which are accessible in the upper respiratory tract, against two human-specific respiratory pathogens. We studied: (i) neuropeptide-mediated direct antibacterial activity exerted against Moraxella catarrhalis and nontypeable Haemophilus influenzae, and (ii) indirect immunomodulatory role of these neuropeptides in the neutrophil-mediated phagocytosis of indicated pathogens. RESULTS: We found that 100 micromolar concentrations of CGRP, NPY, SP, and SOM effectively permeabilized bacterial membranes and showed (except SOM) bactericidal activity against both pathogens. SOM acted only bacteriostatically. However the killing efficacy was dependent on the bactericidal assay used. The rank order of killing NP effect was: NPY ≥ CGRP > SP >> SOM and correlated with their potency to permeabilize bacterial membranes. The killing and permeabilization activity of the analyzed NPs showed significant correlation with several physicochemical properties and amino acid composition of the neuropeptides. M. catarrhalis was more sensitive to neuropeptides than nontypeable H. influenzae.The immunomodulatory bimodal effect of physiological concentrations of CGRP, NPY, and SP on the phagocytic function of human neutrophils against M. catarrhalis and H. influenzae was observed both in the ingestion (pathogen uptake) and reactive oxygen species generation stages. This effect was also dependent on the distinct type of pathogen recognition (opsonic versus nonopsonic). CONCLUSIONS: The present results indicate that neuropeptides such as CGRP, NPY, and SP can effectively participate in the direct and indirect elimination of human-specific respiratory pathogens. Because the studied NPs show both direct and indirect modulating antimicrobial potency, they seem to be important molecules involved in the innate host defense against M. catarrhalis and nontypeable H. influenzae.

Somatostatin-immunoreactive senile plaque-like structures in the frontal cortex and nucleus accumbens of aged tree shrews and Japanese macaques.

BACKGROUND: Previously, we demonstrated decreased expression of somatostatin mRNA in aged macaque brain, particularly in the prefrontal cortex. To investigate whether or not this age-dependent decrease in mRNA is related to morphological changes, we analyzed somatostatin cells in the cerebra of aged Japanese macaques and compared them with those in rats and tree shrews, the latter of which are closely related to primates. METHODS: Brains of aged macaques, tree shrews, and rats were investigated by immunohistochemistry with special emphasis on somatostatin. RESULTS: We observed degenerating somatostatin-immunoreactive cells in the cortices of aged macaques and tree shrews. Somatostatin-immunoreactive senile plaque-like structures were found in areas 6 and 8 and in the nucleus accumbens of macaques, as well as in the nucleus accumbens and the cortex of aged tree shrews, where amyloid accumulations were observed. CONCLUSIONS: Somatostatin degenerations may be related to amyloid accumulations and may play roles in impairments of cognitive functions during aging.

Immunohistochemical identification and localisation of gastrin and somatostatin in endocrine cells of human pyloric gastric mucosa.

The detailed description of the distribution of endocrine cells G and D producing important hormones that regulate activation of other cells in the human stomach may be a valuable source of information for opinions about mucosa changes in different diseases of the alimentary tract. The density and distribution of immunoreactive G and D cells in the pylorus of humans (donors of organs) were evaluated. The pylorus samples were collected after other organs were harvested for transplantation. The number of G cells in the pyloric mucosa of healthy people was higher than the number of D cells. G and D cells were distributed between columnar cells of epithelium mucosa. Multiform endocrine cells generally occurred: gastrin in the middle third of the mucosa and somatostatin cells in the basal half of the pyloric mucosa. The investigation of the pyloric part of the healthy human stomach showed a characteristic distribution of cells that reacted with antisera against gastrin and somatostatin.

Effect of active immunization against a recombinant mouse granulocyte-macrophage colony-stimulating factor/somatostatin fusion protein on the growth of mice.

Female BALB/c mice were actively immunized subcutaneously with a recombinant protein of granulocyte-macrophage colony-stimulating factor (GM-CSF) fused with somatostatin (SS) (GM-CSF/SS). Fifty-four days after the primary immunization, the body weight of the immunized mice increased by 4.62% compared with the control (P < 0.05), together with the induction of detectable serum antibodies against SS. The level of serum growth hormone (GH) elevated by 44.54% (P < 0.05) and the mRNA expression of muscular IGF-1 increased by 94% for the GM-CSF/SS-treated mice. The results indicated that the recombinant protein GM-CSF/SS was efficient in inducing specific immunity against SS, subsequently leading to the increase of the GH level by SS neutralization, and ultimately improving the growth of mice.

Calretinin and somatostatin immunoreactivities label different human submucosal neuron populations.

In human myenteric plexus, calretinin (CALR) and somatostatin (SOM) coexist in Dogiel Type II neurons, which were considered as intrinsic primary afferent neurons in the guinea pig. The aims of this study were to test if also human submucosal neurons costain immunohistochemically for CALR and SOM and whether these or other neurons display Type II morphology. Two sets of submucosal wholemounts of small and large intestine from 29 patients (median age 65 years) were triple stained for CALR, SOM, and human neuronal protein Hu C/D (HU, a pan-neuronal marker) as well as for CALR, SOM, and peripherin (PER), respectively. Only exceptionally, neurons coreactive for both CALR and SOM were found. The three major groups of neurons were CALR-/HU-coreactive (CALR-neurons), SOM-/HU-coreactive (SOM-neurons), and HU-alone-positive neurons. We observed significantly more CALR-neurons in the external submucosal plexus (ESP) of all regions and more SOM-neurons in the internal submucosal plexus (ISP), although with substantial interindividual variations. Comparisons of small vs. large intestine revealed more SOM-neurons (ESP: 29% vs. 4%, ISP: 40% vs. 13%) but fewer CALR-neurons (ESP: 37% vs. 77%, ISP: 21% vs. 67%) in small intestine. Morphologically, CALR-neurons had multiple processes; in some cases, we identified multidendritic/uniaxonal neurons. In contrast, SOM-neurons had mostly only one process. The functions of both populations as possible primary afferent neurons, interneurons, secretomotor neurons, or vasomotor neurons are discussed. Future morphochemical distinction of these groups may reveal different subgroups.

Effects of immunization against a DNA vaccine encoding somatostatin gene (pGM-CSF/SS) by attenuated Salmonella typhimurium on growth, reproduction and lactation in female mice.

A novel somatostatin (SS) DNA vaccine (pGM-CSF/SS), delivered orally by attenuated Salmonella typhimurium (CSO22), was used to immunize female mice at 5, 7, and 11 wk of age; the objective was to investigate the humoral immune response and effects of this vaccine on growth, reproduction and lactation. The pGM-CSF/SS induced SS-specific antibodies, which peaked (3.69 ± 0.89; mean ± S.D) 4 wk after the first booster immunization. Compared with a saline-treated control group, body weight gain of a pGM-CSF/SS immunized group increased 30.3% (23.88 vs. 18.32 g, P < 0.05) during the growth period (from 2 wk after primary immunization to 4 wk after the first booster immunization). Immunized mice had higher plasma estradiol concentrations (84.10 ± 2.16 vs. 81.45 ± 2.12 pg/ml, P < 0.05) and a shorter estrous cycle (4.06 ± 0.75 vs. 5.33 ± 0.49 d, P < 0.05), but serum progesterone concentrations were not significantly affected. Since offspring produced by immunized mice gained weight faster (P < 0.05) in the first 2 wk of life (4.27 ± 0.62 and 7.81 ± 1.30 g in Weeks 1 and 2, respectively vs. 3.70 ± 0.23 and 7.14 ± 0.48 g), we inferred that pGM-CSF/SS could have a direct or indirect role in regulating lactation in mice. In conclusion, GM-CSF and CSO22 served as adjuvant and attenuated live vector, respectively, with efficient oral delivery of an SS DNA vaccine which successfully induced a humoral immune response and enhanced rate of weight gain. Furthermore, the DNA vaccine pGM-CSF/SS affected plasma estradiol concentrations and the estrous cycle, and seemed to enhance lactation performance of female mice.

Effect of genetic adjuvants on immune respondance, growth and hormone levels in somatostatin DNA vaccination-induced Hu lambs.

The aim of current study was to evaluate the prospects of adjuvants against DNA vaccination (pES/2SS) encoding somatostatin (SS) and hepatitis B surface antigen fusion gene. A total of 60 female Hu lambs were divided into 6 groups and vaccinated in the context of various adjuvants (and controls): pE-CpG, Escherichia coli DH5alpha DNA, crude liposomes or GM-CSF in combination with the pES/2SS plasmid. Controls included pES/2SS only vaccinated and physiological saline groups. The antibody against SS level in the E. coli DH5alpha DNA group was significantly increased compared to that in the pES/2SS vaccine alone. Vaccination with pES/2SS/pE-CpG or pES/2SS/E. coli DH5alpha resulted in elevated weight gains that were 33.0 and 31.6% higher, respectively, than in saline group and pES/2SS only vaccinated controls. The concentrations of GH and IGF-I in the DNA vaccine groups were remarkably higher than those in the saline group, and those with positive antibody higher than negative antibody. These results suggested that different adjuvant/pES/2SS combinations can enhance the immune effect and had significant positive effects on growth.