Effects of an anti-gonadotrophin releasing hormone vaccine on the morphology, structure and function of bull testes.

Castration reduces aggressive and sexual behaviour and provides better carcass quality in bull calves. Vaccination against gonadotrophin-releasing hormone (GnRH) is used as an alternative to surgical castration for the purposes of reducing pain and distress in the animals. Currently, no anti-GnRH vaccine has been authorized for use in cattle in the European Union. The aim of the present study was to assess the effect of an anti-GnRH swine-specific vaccine (Improvac®, Zoetis, USA) on the morphology, structure and function of bull testes. Animals were vaccinated at days 1, 21 and 104 of the experimental period and were classified based on their live weight into the following two groups: LIGHT (172.9 ±â€¯30.00 kg) and HEAVY (323.8 ±â€¯37.79 kg). The scrotal circumference was measured on day 1 and prior to slaughter (day 164). At slaughter, the sperm motility and concentration in the caudae epididymis were assessed. Testes were weighed, measured and examined using ultrasound, and then tissue samples were collected and fixed in formalin. Histological and immunohistochemical studies were performed on the testes to measure the diameter of the seminiferous tubules and assess the testicular cell populations. The results revealed that suppression of testicular development was associated with the use of the Improvac® vaccine, which resulted in a smaller size of the testes and impaired spermatid production. However, the effect of Improvac® was more pronounced and consistent in calves vaccinated at a low live weight than at a heavy live weight, which suggested that vaccination is more effective when calves are vaccinated before or early during puberty. However, testes from calves vaccinated at a low live weight were more prone to the development of intraluminal concretions in the seminiferous tubules.

Hematopoietic or Osteoclast-Specific Deletion of Syk Leads to Increased Bone Mass in Experimental Mice.

Syk is a non-receptor tyrosine kinase critically involved in signaling by various immunoreceptors including B-cell-receptors and activating Fc-receptors. We have previously shown that Syk also mediates immunoreceptor-like signals required for the in vitro development and function of osteoclasts. However, the perinatal lethality of Syk-/- mice precluded the analysis of the role of Syk in in vivo bone metabolism. To overcome that problem, we generated mice with osteoclast-specific (SykΔOC ) or hematopoietic (SykΔHaemo ) Syk deficiency by conditional deletion of Syk using Cre recombinase expressed under the control of the Ctsk or Vav1 promoter, respectively. Micro-CT analysis revealed increased bone trabecular density in both SykΔOC and SykΔHaemo mice, although hematopoietic Syk deficiency caused a more severe phenotype than osteoclast-specific Syk deficiency. Osteoclast-specific Syk deficiency reduced, whereas hematopoietic Syk deficiency completely blocked in vitro development of osteoclasts. Both interventions inhibited the resorptive activity of osteoclasts and osteoclast-specific gene expression. Kinetic analysis of Syk protein levels, Cre expression and the genomic deletion of the Sykflox allele revealed complete and early deletion of Syk from SykΔHaemo osteoclasts whereas Syk was incompletely deleted at a later stage of osteoclast development from SykΔOC cultures. Those results provide an explanation for the in vivo and in vitro difference between the SykΔOC and SykΔHaemo mutant strains and suggest late activation of, and incomplete target gene deletion upon, osteoclast-specific Cre expression driven by the Ctsk promoter. Taken together, our results indicate that Syk plays an indispensable role in osteoclast-mediated in vivo bone resorption and suggest that Syk-specific inhibitors may provide therapeutic benefit in inflammatory and other diseases characterized by excessive osteoclast-mediated bone resorption.

The effects of in ovo administration of encapsulated Toll-like receptor 21 ligand as an adjuvant with Marek's disease vaccine.

Marek's Disease Virus (MDV) is the causative agent of a lymphoproliferative disease, Marek's disease (MD) in chickens. MD is only controlled by mass vaccination; however, immunity induced by MD vaccines is unable to prevent MDV replication and transmission. The herpesvirus of turkey (HVT) vaccine is one of the most widely used MD vaccines in poultry industry. Vaccines can be adjuvanted with Toll-like receptor ligands (TLR-Ls) to enhance their efficacy. In this study, we examined whether combining TLR-Ls with HVT can boost host immunity against MD and improve its efficacy. Results demonstrated that HVT alone or HVT combined with encapsulated CpG-ODN partially protected chickens from tumor incidence and reduced virus replication compared to the control group. However, encapsulated CpG-ODN only moderately, but not significantly, improved HVT efficacy and reduced tumor incidence from 53% to 33%. Further investigation of cytokine gene profiles in spleen and bursa of Fabricius revealed an inverse association between interleukin (IL)-10 and IL-18 expression and protection conferred by different treatments. In addition, the results of this study raise the possibility that interferon (IFN)-ß and IFN-γ induced by the treatments may exert anti-viral responses against MDV replication in the bursa of Fabricius at early stage of MDV infection in chickens.

Topical Sunitinib ointment alleviates Psoriasis-like inflammation by inhibiting the proliferation and apoptosis of keratinocytes.

Psoriasis is a chronic auto-immune inflammation disease with skin lesions and abnormal keratinocyte proliferation. Sunitinib, a multi-targeted tyrosine kinase inhibitor, is known to selectively inhibit several growth factor receptors, including vascular endothelial growth factor receptor, platelet-derived growth factor receptor and stem cell factor. It was reported that a patient with renal cell carcinoma (RCC) whose psoriatic lesion was resolved dramatically during treatment with Sunitinib, however, the mechanism is still unclear. We applied Sunitinib ointment to treat imiquimod-induced mouse model of psoriasis and found that Sunitinib ointment could alleviate imiquimod-induced psoriasis-like inflammation and reduce the Ki67 expression, while Sunitinib ointment couldn't reduce imiquimod-induced splenomegaly of the mouse model, then we concentrated on studying the effect of Sunitinib on the proliferation and apoptosis of keratinocytes, we cultivated HaCaT cells with epidermal growth factor (HaCaT/E cells) to represent as a state of highly proliferative psoriatic keratinocytes. We found that Sunitinib could inhibit the proliferation of Hacat/E cell in a time and concentration dependent manner by influencing the expression level of cell cycle protein D1, cycle protein E1, in addition, Sunitinib could induce the apoptosis of Hacat/E cell and up-regulate the expression of poly ADP-ribose polymerase (PARP). Sunitinib down-regulated the expression of phosphorylated signal transduction and activator of transcription 3 (p-Stat3) of Hacat/E cells significantly. We conclude that Sunitinib alleviates imiquimod-induced psoriasis-like inflammation by regulating the proliferation and apoptosis of HaCaT cells through inhibiting the expression of p-Stat3.

Establishment of a Novel Autoimmune Experimental Model of Bladder Pain Syndrome/Interstitial Cystitis in C57BL/6 Mice.

The aim of this study is to identify whether vaccinating twice with bladder homogenate can establish a new model of experimental autoimmune cystitis (EAC) in C57BL/6 strain mice. C57BL/6 mice were vaccinated with bladder homogenate in complete Freund's adjuvant (CFA) and boost immunized with bladder homogenate in incomplete Freund's adjuvant (IFA) after 2 weeks were used as the EAC model. Mice immunized with phosphate-buffered saline (PBS) in CFA or IFA were used as the control. Micturition habits and suprapubic-pelvic pain threshold were measured 4 weeks after primary immunization. Bladder to body weight ratios and expression of inflammatory cytokines and neurokinin 1 receptor (NK1R) were then examined. Histologic and immunohistochemical examination of the bladder was carried out, and IL-1ß, IFN-γ, and TNF-α production by the kidneys, liver, and lungs was also tested. Double-immunized mice were extensively sensitive to pressure applied on the pelvic area (P < 0.001). Compared to single-immunized mice or controls, double-immunized mice showed more micturition frequency, lower urine output per micturition, higher bladder to body weight ratio, and significant elevation in the expression of inflammatory cytokines, including IL-1ß, IL-4, IL-6, IL-10, IFN-γ, and TNF-α (all P < 0.05). NK1R gene expression was significantly increased in double-immunized mice compared to the other three groups (P < 0.001). A nonspecific immune response occurred in the liver but was much weaker than bladder inflammation. Our dual immunization EAC model in C57BL/6 mice can effectively mimic the symptoms and pathophysiologic characteristics of BPS/IC and thus can be widely used to investigate the pathogenesis and therapeutic strategies of BPS/IC.

Evolution of testes characteristics in entire and immunocastrated male pigs from 30 to 120 kg live weight as assessed by computed tomography with perspective on boar taint.

The present study addressed (1) the levels of boar taint compounds in entire (EM) and immunocastrated (IM) male pigs during their growth, (2) the evolution of testes volume and density and (3) the relationship between physical characteristics of the testes and boar taint compounds. For that purpose 24 EM and 20 IM pigs were CT scanned at several body weights (TBW). After each scanning a subsample of pigs was slaughtered, and subcutaneous fat was collected to determine androstenone and skatole concentration. Additional subsample (n=4/sex) was CT scanned 13 days after the second vaccination (V2). Testes density changes with growth, is different in EM and IM, but is not a reliable marker of the level of boar taint compounds. On the other hand, testes to body volume ratio is a better predictor for androstenone and could provide a good tool at slaughter plants to detect immunocastrated pigs with high boar taint compounds.

Effects of corticosterone and dietary energy on immune function of broiler chickens.

An experiment was conducted to investigate the effects of dietary energy level on the performance and immune function of stressed broiler chickens (Gallus gallus domesticus). A total of 96 three-day-old male broiler chickens (Ross × Ross) were divided into two groups. One group received a high energy (HE) diet and the other group received a low energy (LE) diet for 7 days. At 5 days of age, the chickens from each group were further divided into two sub-groups and received one of the following two treatments for 3 days: (1) subcutaneous injection of corticosterone, twice per day (CORT group; 2 mg of CORT/kg BW in corn oil) and (2) subcutaneous injection of corn oil, twice per day (Control/Sham treatment group). At 10 days of age, samples of blood, duodenum, jejunum, and ileum were obtained. Compared with the other three groups, the LE group treated with CORT had the lowest average daily gain (ADG) and the poorest feed conversion ratio (FCR, P < 0.05). Furthermore, CORT treatment decreased the relative weight (RW) of the bursa independent of the dietary energy level, but it decreased the RW of the thymus only in the chickens fed the LE diet. By contrast, CORT administration decreased the RW of the spleen only in the chickens fed the HE diet (P < 0.05). The plasma total protein, albumin, tumor necrosis factor alpha, interleukin 2 and immunoglobulin G (IgG) levels were affected by the CORT treatment (P < 0.05); however, these factors were not significantly affected by the dietary energy level. Toll-like receptor-5 mRNA level was down-regulated by CORT injection in the duodenum and ileum (P < 0.05) and showed a trend of down-regulation in the jejunum (P=0.0846). The present study showed that CORT treatment induced immunosuppressive effects on the innate immune system of broiler chickens, which were ameliorated by consumption of higher dietary energy.

Intestinal colonization by Candida albicans alters inflammatory responses in Bruton's tyrosine kinase-deficient mice.

The commensal yeast Candida albicans is part of the human intestinal microflora and is considered a "pathobiont", a resident microbe with pathogenic potential yet harmless under normal conditions. The aim of this study was to investigate the effect of C. albicans on inflammation of the intestinal tract and the role of Bruton's tyrosine kinase (Btk). Btk is an enzyme that modulates downstream signaling of multiple receptors involved in innate and adaptive immunity, including the major anti-fungal receptor Dectin-1. Colitis was induced in wild type and Btk-/- mice by treatment with dextran sodium sulfate (DSS) and the gastrointestinal tract of selected treatment groups were then colonized with C. albicans. Colonization by C. albicans neither dampened nor exacerbated inflammation in wild type mice, but colon length and spleen weight were improved in Btk-deficient mice colonized with C. albicans. Neutrophil infiltration was comparable between wild type and Btk-/- mice, but the knockout mice displayed severely reduced numbers of macrophages in the colon during both DSS and DSS/Candida treatment. Smaller numbers and reduced responsiveness of Btk-/- macrophages might partially explain the improved colon length of Btk-/- mice as a result of Candida colonization. Surprisingly, DSS/Candida-treated Btk-/- animals had higher levels of certain pro-inflammatory cytokines and levels of the anti-inflammatory cytokine TGF-ß were reduced compared to wild type. A clustering and correlation analysis showed that for wild type animals, spleen TGF-ß and colon IL-10 and for Btk-/- spleen and colon levels of IL-17A best correlated with the inflammatory parameters. We conclude that in Btk-/- immunocompromised animals, colonization of the gastrointestinal tract by the commensal yeast C. albicans alters inflammatory symptoms associated with colitis.

[Protective effect and mechanism of IL-17 monoclonal antibody on mice with viral myocarditis].

OBJECTIVE: To explore the protective effects of interleukin-17 monoclonal antibody (IL-17 mAb) on viral myocarditis (VMC) mice and its possible molecular mechanisms. METHODS: Ninety BALB/c mice were randomly divided into 4 groups: normal control group (n=15), model group (n=25), isotype control group (n=25) and IL-17 mAb group (n=25). Mice in model, isotype control and IL-17 mAb groups were inoculated with 0.1 mL Eagle's solution containing Coxsackievirus B3 (CVB3) intraperitoneally; and those in normal control group were treated with 0.1 mL Eagle's solution without CVB3. On the day 3 and 5 after inoculation, mice in isotype control and IL-17 mAb groups received intragastric administration of 100 µg non-specific IgG antibody and IL-17 mAb, respectively. On day 7 postinoculation, 5 mice were killed in each group, and the hearts were removed. Virus titer was detected using Reed-Muench method, and CVB3 mRNA copy number was measured by real-time quantitative PCR. All mice were killed on day 14 after weighing body mass (BM). The mortality was compared among groups. Serum was separated and serum cardiac troponin I (cTnI) concentration was detected using ELISA. The heart was removed and weighed to calculate heart index (HM/BM). Histological sections of heart were stained with hematoxylin-eosin and myocardial histopathologic scores were counted under optical microscope. The expression of nuclear factor-κB (NF-κB) p65 was examined by Western blotting. Myocardial interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels were detected by ELISA. RESULTS: The HM/BM, serum cTnI concentration, NF-κB p65 expression level and myocardial IL-6 and TNF-α contents in model group were higher than those in normal control group (P<0.01). In comparison with model and isotype control groups, mortality, HM/BM, serum cTnI concentration, myocardial histopathologic scores, virus titer, CVB3 mRNA copy number, NF-κB p65 expression level, and myocardial IL-6 and TNF-α contents in IL-17 mAb group were significantly reduced (P<0.05 or 0.01). There was no difference in the above indicators between isotype control group and model group(P>0.05). CONCLUSION: IL-17 mAb can improve myocardial injury in VMC mice, and the mechanisms are associated with the inhibition of viral replication and NF-κB activation.

Impact of total-body irradiation on the response to a live bacterial challenge.

PURPOSE: Concern regarding radiation effects on human health continues to increase worldwide. Given that infection is a major cause of morbidity and mortality after exposure, the aim of this study was to evaluate decrements in immune cell populations using a mammalian model subjected to a live bacterial infection. MATERIALS AND METHODS: C57BL/6 mice were exposed to total-body irradiation (TBI) with 3 Gy protons (70 cGy/min). One, 2, 4, 8 or 16 days later, subsets of mice were injected intraperitoneally with live Escherichia coli [055:K59(B5)]. Control groups received no radiation and vehicle (no bacteria). The mice were euthanized for analyses 90-120 min after injection of the bacteria. RESULTS: There were no unexpected effects of radiation or E. coli alone. Despite dramatic radiation-induced decreases in all leukocyte populations in both the blood and spleen, irradiated mice were still able to respond to an immune challenge based on capacity to generate an oxidative burst and secrete inflammatory cytokines, i.e., tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). However, these responses were generally elevated above control values. CONCLUSIONS: Together, these results suggest the possibility for enhanced inflammation-associated tissue injury and increased risk for chronic inflammation.

Immunoregulatory effects of Taishan Pinus massoniana pollen polysaccharide on chicks co-infected with avian leukosis virus and Bordetella avium early in ovo.

In recent years, co-infection of chicken embryos with immunosuppressive viruses and bacteria occurs with an annually increasing frequency. Consequently, studies on new and safe immunoregulators, especially plant polysaccharides, have become a popular topic in the poultry industry. In the present study, we selected 300 specific pathogen free embryonated eggs, which were injected with subgroup B avian leukosis virus (ALV-B) and Bordetella avium (B. avium) to establish an artificial co-infection model. The chicks that hatched from these co-infected embryonated eggs were treated with Taishan Pinus massoniana pollen polysaccharide (TPPPS). Results indicated that relevant indices in the co-infection group were significantly lower than that in B. avium-only group. Furthermore, pathogenicity of B. avium was exacerbated, with the chicks exhibiting decreased body weights. The TPPPS groups exhibited gradual improvements in immune function and developmental status. Therefore, in terms of improving immunologic function and production performance, TPPPS could be used as immunoregulator for immune responses.

Regulation of intestinal immune response by selective removal of the anterior, posterior, or entire pituitary gland in Trichinella spiralis infected golden hamsters.

The influence of anterior pituitary hormones on the gastrointestinal tract of humans and animals has been previously reported. Hypophysectomy (HYPOX) in the rat causes atrophy of the intestinal mucosa, and reduction of gastric secretion and intestinal absorption, as well as increased susceptibility to bacterial and viral infections. However, to our knowledge, no findings have been published concerning the immune response following HYPOX during worm infection, particularly that which is caused by the nematode Trichinella spiralis. The aim of this work was to analyze the effects of total or partial HYPOX on colonization of T. spiralis in the intestinal lumen, together with duodenal and splenic cytokine expression. Our results indicate that 5 days post infection, only neurointermediate pituitary lobectomy (NIL) reduces the number of intestinally recovered T. spiralis larvae. Using semiquantitative inmunofluorescent laser confocal microscopy, we observed that the mean intensity of all tested Th1 cytokines was markedly diminished, even in the duodenum of infected controls. In contrast, a high level of expression of these cytokines was noted in the NIL infected hamsters. Likewise, a significant decrease in the fluorescence intensity of Th2 cytokines (with the exception of IL-4) was apparent in the duodenum of control and sham infected hamsters, compared to animals with NIL surgeries, which showed an increase in the expression of IL-5 and IL-13. Histology of duodenal mucosa from NIL hamsters showed an exacerbated inflammatory infiltrate located along the lamina propria, which was related to the presence of the parasite. We conclude that hormones from each pituitary lobe affect the gastrointestinal immune responses to T. spiralis through various mechanisms.

Dynamics of the systemic components of the chicken (Gallus gallus domesticus) immune system following activation by Escherichia coli; implications for the costs of immunity.

The immune response is thought to be costly and deters from growth and reproduction, but the magnitude and sources of these costs are unknown. Thus, we quantified the changes in mass of leukocytes (CD4(+) and CD8(+) T cells, Bu1(+) IgM(+) and Bu1(+) IgG(+) B cells, monocytes/macrophages, heterophils and thrombocytes) and protective plasma proteins in systemic (non-mucosal) components of adult chickens injected intravenously with dead Escherichia coli. During the first day after E. coli injection most types of blood leukocytes decreased and α-1-acid glycoprotein increased. Specific IgM, specific IgY, total IgM, Bu1(+) lymphocytes in the spleen and bone marrow and thymic CD8(+) lymphocytes increased at 5d post-injection. Quantitatively, the increases in the weight of cells and antibodies due to E. coli were dwarfed by the increase in the weight of the liver and acute phase proteins. Thus the acute phase response was markedly more costly than the subsequent adaptive response. The weight of the cells and proteins of the systemic immune system prior to challenge was 0.14% of body weight. Following E. coli injection, the additional weight of the immune components and the hypertrophy of the liver resulted in a 3.6-fold increase in weight which is equivalent to 18.5% of a large egg.

Periodontal bacteria aggravate experimental autoimmune myocarditis in mice.

Periodontitis is one of the most common infections in humans. Recently, published reports assert that periodontitis is associated with cardiovascular disease. Although it is said that viral, bacterial infections and autoimmune diseases may be the cause of myocarditis, the pathogenesis of it remains unclear. The aim of this study was to investigate the influence of a periodontal pathogen on experimental autoimmune myocarditis (EAM). Porphyromonas gingivalis (P.g.), PBS as a control, were injected into the mice. Histopathological and immunohistochemical analyses were performed. We examined heart mRNA levels using quantitative RT-PCR. The anti-P.g. IgG antibody level in plasma samples of the P.g.-injected group significantly increased compared with the PBS-injected group. Histopathological analysis detected that the myocarditis-affected areas and the fibrotic area in the P.g.-injected EAM group significantly increased compared with the PBS-injected EAM group (P < 0.05). Immunohistochemical analysis detected that more CD11b-positive cells were shown in the heart of the P.g.-injected EAM group compared with the PBS EAM-injected group (P < 0.05). Hearts from the P.g.-injected EAM group showed significantly increased expression of monocyte chemoattractant protein-1, IFN-γ, and matrix metalloproteinase-9 (MMP-9) mRNA compared with the hearts from the PBS-injected EAM group (P < 0.05). On day 7, serum levels of IL-6 were significantly enhanced in the P.g.-injected EAM group compared with the PBS-injected EAM group (P < 0.05). These results showed that P.g. injection could deteriorate EAM in mice through CD11b-positive cells, cytokines, and MMP-9 expression.

Critical mass of splenic autotransplant needed for the development of phagocytic activity in rats.

When total splenectomy is inevitable, heterotopic splenic autotransplantation seems to be the only alternative to maintain the functions of the spleen. The present study was carried out to analyse the critical mass of splenic autotransplant (SAT) for the development of phagocytic activity in rats. Wistar rats were submitted to total splenectomy (TS) alone or in combination with slices of SAT ranging from an average rate of 21·9% (one slice) to 100% (five slices) of the total splenic mass implanted into the greater omentum. Sixteen weeks after the beginning of the experiment, the animals were inoculated intravenously with a suspension of Escherichia coli labelled with Tc-99m. After 20 min, the rats were killed and the liver, lung and spleen or SAT, as well as blood samples were removed to determine the percentage of labelled bacteria uptake in these tissues. As the percentage of the total splenic mass contained in the SAT increased, the bacteria remaining in the blood decreased. From the implant of 26% up to the implant of the total splenic mass (100%) there was no difference in the bacteria remaining in the blood between the healthy animals of the control group and those submitted to TS combined with SAT. This finding shows that the critical mass needed for the development of phagocytic activity of macrophages in splenic autotransplants in adult rats is 26% of the total splenic mass.

Impaired fetal thymic growth precedes clinical preeclampsia: a case-control study.

In preeclampsia the maternal adaptive immune system undergoes specific changes, which are different from the physiological processes associated with healthy pregnancy. Whether preeclampsia also affects the fetal immune system is difficult to investigate, due to limited access to the fetus. We hypothesized that if preeclampsia affects the fetal adaptive immune system this might be associated with early changes in thymic growth. In this case-control study, 53 preeclamptic and 120 healthy control pregnancies were matched for maternal age, gestational age and smoking. Fetal thymus diameter was measured as the greatest width perpendicular to a line connecting sternum and spine based on ultrasound images taken at 17-21 weeks gestation. Independent of fetal and maternal anthropometric measures, thymuses were found to be smaller in preeclamptic pregnancies than healthy controls (16.2 mm versus 18.3 mm, respectively, mean difference=2.1 mm, 95% CI: 0.8-3.3, p<0.001), and the odds of developing preeclampsia was estimated to be 0.72 (95% CI: 0.60-0.86, p<0.001) lower for each 1 mm increase in thymus diameter. There was no correlation between the onset of preeclampsia and fetal thymus size. This is the first study to suggest that fetal thymus growth is reduced before the clinical onset of preeclampsia and precedes any described fetal anomalies or maternal immunological changes associated with preeclampsia. We propose that the fetal adaptive immune system is either passively affected by maternal processes preceding clinical preeclampsia or is actively involved in initiating preeclampsia in later pregnancy.

The gut microbiota regulates bone mass in mice.

The gut microbiota modulates host metabolism and development of immune status. Here we show that the gut microbiota is also a major regulator of bone mass in mice. Germ-free (GF) mice exhibit increased bone mass associated with reduced number of osteoclasts per bone surface compared with conventionally raised (CONV-R) mice. Colonization of GF mice with a normal gut microbiota normalizes bone mass. Furthermore, GF mice have decreased frequency of CD4(+) T cells and CD11b(+) /GR 1 osteoclast precursor cells in bone marrow, which could be normalized by colonization. GF mice exhibited reduced expression of inflammatory cytokines in bone and bone marrow compared with CONV-R mice. In summary, the gut microbiota regulates bone mass in mice, and we provide evidence for a mechanism involving altered immune status in bone and thereby affected osteoclast-mediated bone resorption. Further studies are required to evaluate the gut microbiota as a novel therapeutic target for osteoporosis.

Efnb1 and Efnb2 proteins regulate thymocyte development, peripheral T cell differentiation, and antiviral immune responses and are essential for interleukin-6 (IL-6) signaling.

Erythropoietin-producing hepatocellular kinases (Eph kinases) constitute the largest family of cell membrane receptor tyrosine kinases, and their ligand ephrins are also cell surface molecules. Because of promiscuous interaction between Ephs and ephrins, there is considerable redundancy in this system, reflecting the essential roles of these molecules in the biological system through evolution. In this study, both Efnb1 and Efnb2 were null-mutated in the T cell compartment of mice through loxP-mediated gene deletion. Mice with this double conditional mutation (double KO mice) showed reduced thymus and spleen size and cellularity. There was a significant decrease in the DN4, double positive, and single positive thymocyte subpopulations and mature CD4 and CD8 cells in the periphery. dKO thymocytes and peripheral T cells failed to compete with their WT counterparts in irradiated recipients, and the T cells showed compromised ability of homeostatic expansion. dKO naive T cells were inferior in differentiating into Th1 and Th17 effectors in vitro. The dKO mice showed diminished immune response against LCMV infection. Mechanistic studies revealed that IL-6 signaling in dKO T cells was compromised, in terms of abated induction of STAT3 phosphorylation upon IL-6 stimulation. This defect likely contributed to the observed in vitro and in vivo phenotype in dKO mice. This study revealed novel roles of Efnb1 and Efnb2 in T cell development and function.

Neonatal androgenization affects the efficiency of ß-adrenoceptor-mediated modulation of thymopoiesis.

We tested the hypothesis that neonatal androgenization affects the efficacy of ß-adrenoceptor (ß-AR)-mediated fine tuning of thymopoiesis in adult female rats by modulating the thymic noradrenaline (NA) level and/or ß-AR expression. In adult rats administered with 1000 µg testosterone enanthate at postnatal day 2 a higher density of catecholamine (CA)-synthesizing thymic cells, including thymocytes, and a rise in their CA content was found. In addition, in these animals increased thymic noradrenergic nerve fiber fluorescence intensity, reflecting their increased CA content, was detected. These changes were followed by an increase in thymic NA concentration. The rise in thymic NA content in thymic nerve fibers and cells was associated with changes in the expression of mRNA for enzymes controlling pivotal steps in NA biosynthesis (tyrosine hydroxylase, dopamine-ß-hydroxylase) and inactivation (monoamine oxidase). In contrast, the thymic level of ß(2)-AR mRNA on a per cell basis and the receptor surface density on thymocytes was reduced in testosterone-treated (TT) rats. As a consequence, 14-day-long treatment with propranolol, a ß-AR blocker, was ineffective in modulating T-cell differentiation/maturation in TT rats. In conclusion, the study indicates the importance of the neonatal sex steroid milieu for shaping the immunomodulatory capacity of the thymic NA/ß-AR signaling system in adult rats.

Effects of early vaccination with Improvac(®) on the development and function of reproductive organs of male pigs.

Gonadotropin-releasing hormone (GnRH) vaccine (Improvac(®)) is effective at diminishing boar taint by interfering with testis function. Early pre-pubertal vaccination at 10 and 14 weeks-of-age could be desirable if sufficient and sustained effects could be achieved. Crossbred male pigs (n=24) were randomly assigned to three groups each with eight individuals: an unvaccinated control group, one group vaccinated with Improvac(®) early at ages 10 and 14 weeks, and a third group vaccinated with Improvac at the standard ages of 16 and 20 weeks. The average age at slaughter was 25 weeks. At slaughter, reductions in testes weight and bulbourethral gland length of vaccinated pigs compared with controls were observed (P<0.001), accompanied by lowered testosterone concentrations in peripheral blood (P<0.001). The diameter of tubuli seminiferi was affected; being 18% smaller in standard and 38% smaller in early vaccinated males, compared with controls (P<0.01). Leydig cells in vaccinated pigs became pycnotic, and their number decreased in early vaccinated pigs. Spermatogenesis was disrupted, evidenced by spermatocyte loss among standard vaccinated pigs to severe spermatogenic arrest among early vaccinated pigs. This histological picture was reflected in the absence of epididymal spermatozoa in 5 of 8 early vaccinated pigs and a dramatic reduction in the remaining 3 early vaccinated pigs. Among standard vaccinated pigs, 5% of the spermatozoa were morphologically normal (>70% in controls, P<0.01). Early vaccination caused a more severe disruption of testicular structure and function than standard vaccination, thus providing an alternative for immunocastration of male pigs.