Thymus Spleen Research Articles

Role of vitamins and minerals in immunity

Immune system is defined as the variety of cells and molecules that have involved in protecting humans/animals from the invasion of pathogenic microorganisms/antigens. The immune system structures; thymus spleen, lymph nodes and specific immunity cells which plays a major role in the immune mechanism. This review paper describes the various effects of micro and macro nutrients on the immune system of the human body.

Immunofluorescent characterization of innervation and nerve-immune cell neighborhood in mouse thymus.

The central nervous system impacts the immune system mainly by regulating the systemic concentration of humoral substances, whereas the peripheral nervous system (PNS) communicates with the immune system specifically according to local "hardwiring" of sympathetic/parasympathetic (efferent) and sensory (afferent) nerves to the primary and secondary lymphoid tissue/organs (e.g., thymus spleen and lymph nodes). In the present study, we use immunofluorescent staining of neurofilament-heavy to reveal the distribution of nerve fibers and the nerve-immune cell neighborhood inside the mouse thymus. Our results demonstrate (a) the presence of an extensive meshwork of nerve fibers in all thymic compartments, including the capsule, subcapsular region, cortex, cortico-medullary junction and medulla; (b) close associations of nerve fibers with blood vessels (including the postcapillary venules), indicating the neural control of blood circulation and immune cell dynamics inside the thymus; (c) the close proximity of nerve fibers to various subsets of thymocytes (e.g., CD4+, CD8+ and CD4+CD8+), dendritic cells (e.g., B220+, CD4+, CD8+ and F4/80+), macrophages (Mac1+ and F4/80+) and B cells. Our novel findings concerning thymic innervation and the nerve-immune cell neighborhood in situ should facilitate the understanding of bi-directional communications between the PNS and primary lymphoid organs. Since the innervation of lymphoid organs, including the thymus, may play essential roles in the pathogenesis and progression of some neuroimmune, infectious and autoimmune diseases, better knowledge of PNS-immune system crosstalk should benefit the development of potential therapies for these diseases.

Effect of Dietary Supplementation of a Mix of Chestnut and Quebracho Tannins on Intestinal Morphology, Bacterial Load, Eimeria spp oocyst Excretion and Immune Response after Vaccination in Rabbits

Among plant products, tannins exhibited a strong antioxidant activity and their employment was studied as food or feed addictive with positive effects. Nevertheless, their health-enhancing properties remain to be completely clarified, particularly in rabbits. The aim of the present study was to investigate the influence of a mix of chestnut and quebracho tannins as supplementation in rabbit diet on intestinal morphology, as well as bacterial loads and Eimeria spp coccidial oocyst excretion and humoral immune response after vaccination. Rabbits were fed four different diets: basal diet (negative control, group CN), basal diet with anticoccidial supplementation (positive control, group CP) and basal diet with tannins mix 0.3% (group T0.3) or 0.6% (group T0.6). Samples of intestine, liver, spleen thymus, mesenteric lymph nodes, kidney and heart were submitted to histopathologic investigations. Morphometric analyses were performed on portion of duodenum, jejunum and ileum. Intestinal contents were analyzed by flotation test for Eimeria spp. oocysts excretion and by microbiological assays for Clostridium perfringens and Escherichia coli. Rabbits belonging to the four experimental groups were vaccinated by means of a live attenuated myxomatosis virus and sera were collected individually at three time points to determine antibody response.The obtained results demonstratedthe absence of toxic effects of the tannin mix on examined organs, particularly on liver and kidney and any negative influence on the growth performance. A relevant anti-inflammatory effect on the intestinal tract, a reduction of Eimeria spp. oocysts excretion and a positive immunomodulatory and antibacterial effects were also observed. Diets supplemented with the tannins mix affected also the morphology of examined intestinal tracts, particularly duodenum and ileum.

Mechanism of Rhei Radix et Rhizoma combined with Scutellariae Radix on liver inflammation in rats with endotoxin disease based on p38MAPK pathway

To explore the mechanism of Rhei Radix et Rhizoma combined with Scutellariae Radix in regulatory lipopolysaccharide (LPS)-induced liver inflammation in rats with endotoxin blood, 50 male SD rats were selected and randomly divided into blank group, model group, dexamethasone group, herbal pair high dose group, herbal pair low dose group, with 10 in each group. Rats in each were given preventive drugs for 7 consecutive days. At 0.5 h after the final administration, the model was built through the tail vein injection with LPS (5 mg•kg⁻¹). Then, animal anal temperatures were determined and recorded once every 0.5 h. The rats were killed at 4 h after the modeling to determine spleen thymus coefficient. ELISA method was used to detect cytokines interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNF-α) in liver tissues. The colorimetric method was applied in determination of oxidation nitrogen (NO) content in liver tissues. Western Blot method was adopted to detect Toll-like receptor protein 4, p38MAPK p38MAPK, phosphorylated p38MAPK (p-p38MAPK) and nitric oxide synthase (iNOS) protein expressions. The results showed that compared with the blank group, in the model group, TLR4 protein expression, iNOS protein expression and p38 phosphorylation expression, IL-1β, NO and TNF-α content increased significantly in liver tissues (P<0.05 or P<0.01). And compared with the model group, the herbal pair high dose group showed significantly reduction in IL-1β, NO and TNF-α expressions in rat liver tissues (P<0.05 or P<0.01), down-regulation in iNOS protein expression and p38 phosphorylation expression in rat liver tissues (P<0.05), but without significant up-regulation in TLR4 protein. Low-dose herbal pair can significantly reduce IL-1β and NO expression in model rat liver tissues (P<0.01), significantly down-regulate iNOS protein expression (P<0.01), with a slight down-regulation in phosphorylation of p38 but no statistical significance, and no reduction in TLR4 expression. In conclusion, the compatibility of Rhei Radix et Rhizoma combined with Scutellariae Radix may reduce the expression of iNOS protein and the release of inflammatory cytokines IL-1β, NO and TNF-α by decreasing p38 protein phosphorylation expression and blocking p38MAPK signaling pathways, so as to alleviate the inflammation reaction and protect the liver.

Novel function of perforin in negatively regulating CD4+ T cell activation by affecting calcium signaling

Perforin is a pore-forming protein engaged mainly in mediating target T cell death and is employed by cytotoxic T lymphocytes (CTLs) and natural killer cells. However, whether it also plays a role in conventional CD4(+) T cell function remains unclear. Here we report that in perforin-deficient (PKO) mice, CD4(+) T cells are hyperproliferative in response to T cell receptor (TCR) stimulation. This feature of hyperproliferation is accompanied by the enhancement both in cell division and in IL-2 secretion. It seems that the perforin deficiency does not influence T cell development in thymus spleen and lymph node. In vivo, perforin deficiency results in increased antigen-specific T cell proliferation and antibody production. Furthermore, PKO mice are more susceptible to experimental autoimmune uveitis. To address the molecular mechanism, we found that after TCR stimulation, CD4(+) T cells from PKO mice display an increased intracellular calcium flux and subsequently enhance activation of transcription factor NFAT1. Our results indicate that perforin plays a negative role in regulating CD4(+) T cell activation and immune response by affecting TCR-dependent Ca(2+) signaling.

A Study on Immunopathologic Effect of Thiram Toxicosis in Broiler Chicken

An investigation was undertaken to study the body weight gain and feed conversion efficiency in broiler chicken fed with thiram a fungicide used for treating corn and storing food grains. Forty eight birds were randomly distributed into four groups of twelve each and thiram was incorporated at 15, 30 and 60 ppm into the toxin free diet for four weeks from the day of hatch. Blood samples were collected, sera separated and HI titres were measured in the control and treated sera. Birds were sacrificed at the end of second and fourth week for detailed examination of lymphoid organs. There was a significant reduction in the antibody titre in the thiram fed birds. Lymphocyte proliferation assay conducted from the lymphocytes prepared from the spleen showed significant reduction in the stimulation index. Histopathology of the lymphoid organs including bursa, spleen thymus and caecal tonsils showed lymphoid depletion to lymphocytolysis.

Development of the thymus, spleen, lymph nodes and liver in the marsupial, Isoodon macrourus (Northern brown bandicoot, Peramelidae).

We report for the first time the development and morphological characteristics of the spleen thymus, lymph nodes and liver of the northern brown bandicoot, Isoodon macrourus. To date few marsupial species have been studied. The development and morphological characteristics of the organs shared the typical features of those few other marsupials studied as well as those of eutherians. These suggest comparative functional properties with the eutherian immune system. The thymus differentiated within the first week of pouch life and showed evidence of immunolymphopoiesis up to juvenile stages. The spleen, though seeded by lymphocytes within the first week of pouch life, was slower to mature, but differentiated and showed signs of immunocompetency by the time young left the pouch. The mature spleen displayed the same anatomical blood filtering and immunosurveillance properties as that of the eutherian spleen, with evidence of erythrocyte destruction, thrombopoietic activity, activation and differentiation of immunocompetent lymphocytes. However, the absence of sheathed capillary structures in the spleen may indicate differences in the humoral response to circulating antigens. Similarly, lymph nodes also mature by this stage with anterior nodes appearing before posterior nodes. The mature lymph nodes displayed structural features of secondary immuno-lymphoid organs consistent with production of immune responses. Finally, the liver displayed haemopoietic activity for the first four weeks of pouch life. The pattern of development in the bandicoot appears to parallel the pattern reported for other marsupials, yet the thymus matures considerably earlier than previously reported and may be of significance in the development and onset of cell-mediated immunity. Current studies to characterise cellular components, such as T/B lymphocyes and accessory cells of these organs will help to define the mechanisms of immune recognition, activation and hence outline the basis of the marsupial humoral and cellular immunity.

Pathogenesis of porcine circovirus; experimental infections of colostrum deprived piglets and examination of pig foetal material

The results of virus and antigen distribution following experimental infection of colostrum deprived pigs with pig circovirus (PCV) by oral/nasal and intravenous routes are reported. PCV and antigen were detected using virus isolation and indirect immunofluorescence on cryostat sections respectively. PCV antigen was detected in tissues throughout the body but primarily in spleen thymus, and lung. No PCV antigen or virus was detected in tissue samples from the central nervous system. Examination of pig foetal material from field cases of abortion/stillbirth resulted in 3 PCV isolates from 2 sera and a spleen sample from 2 groups of stillborn piglets from the same farm. No antibody to PCV alone was detected in 160 foetal sera tested. These results suggest that transplacental infection with PCV does occur, possibly prior to foetal immunocompetance. However, it is probably not a significant cause of reproductive disorders in pigs in Northern Ireland.

In vitro synthesis of the foetal alpha 1-globulin in man.

Synthesis of fetal alpha-1-globulin (AFP) during fetal life was investigated to obtain information on the level of this protein in fetal sera. Tissues and sera were obtained from fetuses born alive but who died immediately after delivery. Short-term cultures of fetal and adult tissues were carried out. The anti-AFP serum was prepared in a rabbit by immunization with serum from a 20-week-old fetus. De novo synthesis of proteins was detected and analyzed by autoradiography of the immunoelectrophoretic pattern. Synthesis of AFP was found in 28/30 fetal liver cultures. During the 10-20 weeks of gestation synthesis of AFP was greater than after this period. Culture fluids of fetal spleen thymus and lung did not contain any newly synthesized AFP. Cultures of adult liver lymph nodes and bone marrow showed no AFP production. AFP synthesis was also studied in placental tissues from 7 fetuses aged from 11-18 weeks. 2 placental cultures contained newly synthesized AFP. Levels of AFP and albumin in serum of 16 6-22 week old fetuses were determined by radial diffusion. The 6- and 7-week-old fetuses contained only traces of AFP. Protein level increased steadily to a maximum at 14-16 weeks but then decreased. In 39 cord sera the AFP level was between 3 and 17 mg/100 ml (5.5 mg average). Albumin in fetal serum increased gradually with age; after Week 20 of gestation the ratio of AFP to albumin fell below 1:10. Therefore the greatest amounts of AFP were synthesized during gestation Weeks 10-20. Synthesis then diminished--in humans as well as other mammals--possibly as a result either of the disappearance of cells exclusively producing AFP or of a regulatory mechanism at the intracellular level.