Selenium supplementation influences growth performance, antioxidant status and immune response in lambs

To investigate and compare the effect of inorganic and organic Se supplementation, 18 male lambs (24.68 ± 2.89 kg mean body weight, about 8–9 months of age) were divided into three groups of six animals in each, following randomized block design. While animals in the control group (Gr I) were fed a standard TMR containing 195 g/kg crushed maize grain, 175.5 g/kg soybean meal, 260 g/kg wheat bran, 13 g/kg mineral mixture (without Se), 6.5 g/kg common salt and 350 g/kg wheat straw, animals in Gr II and Gr III were additionally supplemented with 0.15 mg Se/kg of diet through sodium selenite (inorganic Se) and Jevsel-101 (organic Se), respectively. Experimental feeding was done for a period of 90 days. To assess the humoral immune response, all the lambs were intramuscularly inoculated with a single dose (2 mL) of Haemorrhagic septicaemia oil adjuvant vaccine on day 0; and blood samples were collected on day 0, 30, 60 and 90. Supplementation of Se had no effect on serum total cholesterol, total protein, albumin, globulin, albumin:globulin ratio, T₃, T₄, T₄:T₃ ratio; serum Ca and P levels and SGOT and SGPT activity. However, there was a significant increase in the serum Se level, RBC GSH-Px activity and humoral immune response in both the Se supplemented groups as compared to control group. Average daily gain (g) was highest (110) in Gr III, followed by Gr II (98.2) and lowest in Gr I (89.1). Thus, supplementation of organic as well as inorganic Se was found to improve the growth rate, humoral immune response and antioxidant status of the lambs; and between two sources, organic Se was more effective than inorganic Se.     

Exercise-induced immune system response: Anti-inflammatory status on peripheral and central organs

A wide array of molecular pathways has been investigated during the past decade in order to understand the mechanisms by which the practice of physical exercise promotes neuroprotection and reduces the risk of developing communicable and non-communicable chronic diseases. While a single session of physical exercise may represent a challenge for cell homeostasis, repeated physical exercise sessions will improve immunosurveillance and immunocompetence. Additionally, immune cells from the central nervous system will acquire an anti-inflammatory phenotype, protecting central functions from age-induced cognitive decline. This review highlights the exercise-induced anti-inflammatory effect on the prevention or treatment of common chronic clinical and experimental settings. It also suggests the use of pterins in biological fluids as sensitive biomarkers to follow the anti-inflammatory effect of physical exercise.     

Zinc status and immune system relationship

The essentiality of zinc for humans was first documented by Prasad in the 1960s. The main clinical manifestations associated with zinc deficiency are growth retardation, hypogonadism, diarrhea, and increased susceptibility to infectious diseases. Thus, in the past 25 yr, there was an increased interest of researchers in studying the role of zinc in human immunity. Although mechanistic research has been carried out using animal models, there are several studies in humans with similar results. This work is an attempt to review the information available in this field to understand the important role that zinc plays in the normal development and function of the immune system.     

All in the timing: how fruit nutritional content influences the timing of fruit consumption of two invasive shrubs

The functional role that invasive species occupy within their new range is of significant interest for those concerned about invasive species management. Of particular importance is the distribution mechanisms of invasive plants. Viburnum dilatatum and Viburnum sieboldii are considered invasive species in New Jersey forest understories. We have observed that while the fruit of both species ripens at the same time, there is a difference in how long fruit persists. To better understand the temporal pattern, we examine fruit phenology and consumption, as well as energy density, percentage crude fat, and antioxidant capacity. We hypothesized that the difference in the timing of fruit consumption in these species is largely driven by nutritional content and that fruit with higher energy and fat content are eaten during migration. Our results indicate that V. sieboldii fruit is depleted in the fall, while V. dilatatum fruit persists into winter. In addition, we found that V. sieboldii fruit had higher energy density and 4.4 times as much crude fat compared to that of V. dilatatum fruit. However, V. dilatatum fruit had 9.5 times greater antioxidant capacity than V. sieboldii fruit. We also found that V. sieboldii fruit is mainly consumed by gray catbirds (Dumetella carolinensis) during the fall migration and the primary avian consumer of V. dilatatum fruit are American robins (Turdus migratorius) in the winter when birds are more sedentary. We suspect a mutualistic relationship has developed between these two invasive viburnum species and native avian frugivores. What remains to be seen is what effect different fruiting strategies have on seed dispersal.

     

Chronic stress influences the immune system through the thyroid axis

The aim of the present work was to analyze the effect of chronic stress on thyroid axis and its influence on the immune response. For this purpose a murine model of chronic stress was developed to evaluate and to correlate thyroid hormone levels with humoral alloimmune response. Results show a reduction in serum levels of thyroid hormones, specially a significant decrease in serum levels of triiodotyronine (T3) in stressed animals. On the other hand, alloimmunization was not able to induce an early increment in T3 and thyroxine (T4) levels as it was previously reported in normal animals. In addition, lower titers of alloantibodies were obtained in animals under stress conditions as compared to normal mice. The sustitutive T4 treatment in stressed animals increased significantly alloantibody production as well as the early increment in thyroid hormones after antigenic challenge. These findings suggest that chronic stress induces an alteration of the function of thyroid axis that alters the immune response.     

Sca-1 influences the innate immune response during skeletal muscle regeneration

Efficient muscle regeneration requires the clearance of dead and dying tissue via phagocytosis before remodeling. We have previously shown that mice lacking stem cell antigen-1 (Sca-1) display a defect in skeletal muscle regeneration characterized by increased fibrosis and decreased turnover of the extracellular matrix. In the present study we demonstrate that Sca-1(-/-) mice have a defect in their capacity to recruit soluble IgM, and subsequently C3 complement, to damaged muscle. We hypothesize that this defect in recruitment delays or decreases phagocytosis by macrophages, contributing to the previously observed fibrotic phenotype of these mice. As the primary source of soluble IgM is peritoneal B-1a cells, which are a subset of self-renewing B cells, we analyzed this cell population and observed a significant reduction in B-1a cells in Sca-1(-/-) animals. Interestingly, these mice are protected from ischemia-reperfusion injury, an acute inflammatory reaction also mediated by IgM and C3 complement that has been linked to a deficit in B-1a cells in previous studies. Collectively, these data reveal a novel role for Sca-1 in innate immunity during muscle regeneration and indicate that further elucidation of immuno-myogenic processes will help to better understand and promote muscle regeneration.     

Leptin ameliorates burn-induced multiple organ damage and modulates postburn immune response in rats

The present study was designed to determine whether exogenous leptin reduces remote organ injury in the rats with thermal burn trauma. Leptin (10 microg/kg) or saline was administered intraperitoneally after burn injury, and the rats were decapitated at either 6 or 24 h. Plasma samples of 24-h burn group were assayed for the determination of monocyte and neutrophil apoptosis. Thermal injury increased tissue-associated myeloperoxidase (MPO) activity and microscopic damage scores in the lung, liver, stomach, colon and kidney of both 6- and 24-h burn groups. In the 6-h burn group, leptin reduced microscopic damage score in the liver and kidney only, while damage scores in the 24-h burn group were reduced in all the tissues except the lung. Also, in both burn groups, leptin reduced elevated MPO activity in all tissues except the lung. The percentage of mononuclear cells was significantly reduced at the 24 h of burn injury, while the granulocyte percentage was increased. Leptin treatment, however, had no significant effect on burn-induced reversal of white blood cell ratios. On the other hand, burn-induced increase in the death of mononuclear cells and granulocytes was significantly reduced in leptin-treated rats. The results of the present study suggest that leptin may provide a therapeutic benefit in diminishing burn-induced inflammation and associated multiple organ failure.     

Paraoxonases and cardiovascular diseases: pharmacological and nutritional influences

PURPOSE OF REVIEW: To summarize the new articles published in the last year on paraoxonases, including their expression in cardiovascular diseases, and regulation by pharmacological and nutritional means. RECENT FINDINGS: The elucidation of the crystal structure of the paraoxonase 1 (PON1) gene, obtained by directed evolution, shows that it consists of a six-bladed beta-propeller with a unique active site. PON1 is present in HDL but also in lipoprotein-deficient serum, in VLDL and in chylomicrons. PON1 protects lipids in lipoproteins, in macrophages and in erythrocytes from oxidation. Cellular PON2 and PON3 were also shown to reduce oxidative stress. Beyond its antioxidative properties, PON1 possesses additional antiatherogenic properties against macrophage foam cell formation: attenuation of cholesterol and oxidized lipids influx, inhibition of macrophage cholesterol biosynthesis and stimulation of macrophage cholesterol efflux. The PON1 gene is regulated by Sp1 and protein kinase C, whereas the PON2 gene in macrophages is regulated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. PON1 activity and mass are both reduced in cardiovascular diseases and the hypocholesterolemic drugs, statins, increase serum PON1 activity (by reducing oxidative stress, or by upregulating hepatic PON1 expression). Expression of cellular PON2, like PON1, was upregulated by statins. Nutritional antioxidants, such as polyphenols, increase PON1 mRNA expression and activity, by an aryl hydrocarbon receptor-dependent mechanism. SUMMARY: The elucidation of PON1 structure and its active center has enabled a better understanding of its mechanism of action, including its physio-pathological substrate(s). Some drugs and nutrients including dietary antioxidants and polyphenols considerably increase the activities of paraoxonases which, in turn, can reduce oxidative stress and atherosclerosis development.     

Social status,immune response and parasitism in males: a meta-analysis

In male vertebrates, two conflicting paradigms—the energetic costs of high dominance rank and the chronic stress of low rank—have been proposed to explain patterns of immune function and parasitism. To date, neither paradigm has provided a complete explanation for status-related differences in male health. Here, we applied meta-analyses to test for correlations between male social status, immune responses and parasitism. We used an ecoimmunological framework, which proposes that males should re-allocate investment in different immune components depending on the costs of dominance or subordination. Spanning 297 analyses, from 77 studies on several vertebrate taxa, we found that most immune responses were similar between subordinate and dominant males, and neither dominant nor subordinate males consistently invested in predictable immune components. However, subordinate males displayed significantly lower delayed-type hypersensitivity and higher levels of some inflammatory cytokines than dominant males, while dominant males exhibited relatively lower immunoglobulin responses than subordinate males. Despite few differences in immunity, dominant males exhibited consistently higher parasitism than subordinate males, including protozoan blood parasites, ectoparasites and gastrointestinal helminths. We discuss our results in the context of the costs of dominance and subordination and advocate future work that measures both parasitism and immune responses in wild systems.     

Genetic influences on the immune response of rats to streptococcal A carbohydrate

Selective breeding of Sprague-Dawley rats immunized with group A streptococcal vaccine (GASV) revealed genetic influences on the magnitude of the precipitin response to streptococcal group A carbohydrate (SACHO). After four brother-sister inbreedings, a family of low-precipitin responders (LPR) was segregated from a family of high-precipitin responders (HPR). Precipitin analysis of all four generations of rats bred for low-precipitin responses revealed an earlier influence of inbreeding on the secondary as compared to the primary precipitin response. Prolonged immunization and/or variation in the dose of antigen failed to enhance the magnitude of the precipitin response of LPR. Examination of anti-SACHO antisera for cross-specificity revealed A-variant carbohydrate precipitins in only 1%. This system may offer an opportunity to examine the clinical relevance of anti-SACHO antibodies to rheumatic heart disease.     

Scale invariance of immune system response rates and times: perspectives on immune system architecture and implications for artificial immune systems

Most biological rates and times decrease systematically with increasing organism body size. We use an ordinary differential equation (ODE) model of West Nile Virus in birds to show that pathogen replication rates decline with host body size, but natural immune system (NIS) response rates do not change systematically with body size. The scale-invariant detection and response of the NIS is surprising since the NIS has to search for small quantities of pathogens through larger physical spaces in larger organisms, and also respond by producing larger absolute quantities of antibody in larger organisms. We hypothesize that the NIS has evolved an architecture to efficiently neutralize pathogens. We investigate three different hypothesized NIS architectures using an Agent Based Model (ABM). We find that a sub-modular NIS architecture, in which lymph node number and size both increase sublinearly with body size, efficiently balances the tradeoff between local pathogen detection and global response. This leads to nearly scale-invariant detection and response consistent with experimental data. Similar to the NIS, physical space and resources are also important constraints on distributed systems, for example low-powered robots connected by short-range wireless communication. We show that the sub-modular design principles of the NIS can be applied to problems such as distributed robot control to efficiently balance the tradeoff between local search for a solution and global response or proliferation of the solution. We demonstrate that the lymphatic network of the NIS efficiently balances local and global communication, and we suggest a new approach for Artificial Immune Systems (AIS) that uses a sub-modular architecture to facilitate distributed search.     

Adipose tissue,the immune system and exercise fatigue: how activated lymphocytes compete for lipids

Adipose depots that contain lymph nodes, and probably intermuscular fat in skeletal and cardiac muscle, are specialized to provision adjacent tissue in a paracrine mode. Perinodal adipocytes respond selectively to various cytokines and incorporate proportionately more polyunsaturated fatty acids. Lipolysis in the adipocytes of node-containing depots can be stimulated via inflammation of the enclosed lymph nodes. Repeated immune stimulation elicits properties characteristic of perinodal adipocytes in those elsewhere in the same depot, and hours later in other node-containing depots, but not in nodeless depots. Such site-specific properties of adipose tissue enable partitioning of dietary and metabolic supplies of fatty acids between competing tissues. Local interactions emancipate the peripheral immune system from competing with other tissues for lipids during immune responses, and may be especially important during periods of high demand, such as strenuous exercise. Biopsies of subcutaneous adipose tissue from sites remote from lymph nodes do not adequately represent the composition of fatty acids available to the immune system in situ, and perhaps that supplied to other tissues. Intermuscular fat in skeletal and cardiac muscle may also indicate paracrine relationships between adipocytes and "end-user" tissues. The concept of paracrine interactions between certain adipocytes and "user" tissue may account for the widespread contiguity between these tissues in vivo.     

Host nutritional status: the neglected virulence factor

The emergence of new infectious diseases and old diseases with new pathogenic properties is a burgeoning worldwide problem. Severe acute respiratory syndrome (SARS) and acquired immune deficiency syndrome (AIDS) are just two of the most widely reported recent emerging infectious diseases. What are the factors that contribute to the rapid evolution of viral species? Various hypotheses have been proposed, all involving opportunities for virus spread (for example, agricultural practices, climate changes, rainforest clearing or air travel). However, the nutritional status of the host, until recently, has not been considered a contributing factor to the emergence of infectious disease. In this review, we show that host nutritional status can influence not only the host response to the pathogen, but can also influence the genetic make-up of the viral genome. This latter finding markedly changes our concept of host-pathogen interactions and creates a new paradigm for the study of such phenomena.     

Genetic variability within the innate immune system influences personality traits in women

Raised levels of inflammation markers have been associated with several mental disorders; however, studies regarding the relationship between inflammation or the immune system and various aspects of human behaviour are not numerous. The aim of the present study was to investigate whether an association exists between personality traits and two single nucleotide polymorphisms located in genes that are associated with the innate immune system. The studied population consisted of 42-year-old women recruited from the population registry that had been assessed by means of Karolinska Scales of Personality, a self-reported inventory. The first polymorphism, +1444C>T (rs1130864), is located in the gene coding for C-reactive protein (CRP), a marker of low-grade inflammation. The T-allele has previously been suggested to be linked to raised serum levels of CRP. The second polymorphism, Y402H (1277T>C, rs1061170), is located in the gene coding for complement factor H, an important regulator of the complement system. The C-allele has consistently been associated with age-related macular degeneration. While the +1444T allele was associated with higher scores in the personality traits impulsiveness, monotony avoidance and social desirability, the 1277C polymorphism was associated with higher scores in verbal aggression and lower scores in social desirability. In conclusion, the associations between the personality traits and the studied polymorphisms further support the possible influence of the immune system on mental functions.     

Nutritional status influences peripheral immune cell phenotypes in healthy men in rural Pakistan

ABSTRACT: Immune status is influenced by malnutrition, but how this factor interacts in developing countries and whether these differences are similar to those determined in industrialized countries, is unclear. To establish whether malnutrition-associated immune profiles in a developing country are similar to those in industrialized countries we analyzed peripheral blood immune cell phenotypes by polychromatic flow cytometry in 50 young and 50 elderly subjects. Data on anthropometrics and diet were collected through interviews. Plasma samples were analyzed for common clinical chemistry variables. Subjects in 4 BMI categories differed in their immune parameters demonstrating influence of nutritional status on immunity. This was greater within the young group and affected the CD4 subset more profoundly than the CD8 subset. No nutrition-associated differences were seen in B or NK cells. CD8+ cells as a percentage of CD3+ T cells were positively associated with plasma CRP levels but not other factors. We conclude that there are differences in the immune signatures of obese, overweight and underweight versus normal-weight young and elderly, which seem broadly similar to the more extensively-documented state reported in industrialized countries, despite the marked societal, nutritional and many other differences.