Immune System Of Organism Research Articles

Antimicrobial peptides within the Yellowtail Kingfish (Seriola lalandi)

A number of Seriola species are currently farmed or being investigated as future aquaculture species in countries around the world. However they face a number of issues and limitations which will need to be overcome to ensure future stability and growth, one of which are disease outbreaks. Despite this, very little has been done to understand the immune system of Seriola species and very few immune genes have been characterised. Antimicrobial peptides (AMP) are naturally occurring low molecular weight polypeptides that play a major role in an organism's immune system and act effectively as a first line of defence. This investigation isolates the full length cDNA sequences of two AMP's, piscidin and hepcidin from the yellowtail kingfish (Seriola lalandi). The full-length cDNA of the piscidin gene encodes a 65 amino acid prepropeptide, containing a 25-residue peptide, predicted to form an amphipathic helix-loop-helix structure. Phylogenetic analysis using fish piscidin sequences, showed that this AMP is only found in bony fish within the Acanthomorpha clade and that a possible three groups within the piscidin family exists, with S. lalandi belonging to a particular group. The full-length cDNA of the hepcidin gene encodes a 90 amino acid preprohepcidin, which contains a typical RX(R/K)R motif for cleavage of the mature peptide which comprises of eight conserved cysteine residues. Phylogenetic analysis of known vertebrate hepcidin antimicrobial peptide (HAMP) sequences, shows sequences from the Neoteleostei clade of bony fish form two very separate groups, HAMP1 and HAMP2, with the S. lalandi hepcidin gene grouped with the HAMP1 sequences. HAMP2 sequences are found to have multiple copies within fish and genome analysis showed very clearly that these two groups of genes are located on separate regions on the genome, with the multiple HAMP2 copies formed from tandem gene duplications. Lastly, using qPCR the expression of the S. lalandi piscidin gene within healthy fish was highest within, spleen and gills and lowest in liver, whereas hepcidin was highest in the liver with little or no expression in the spleen and gills.

Netosis: Alternative Defense Method Used by Neutrophils to Fight Pathogen.

Neutrophils form the first line of defense of the innate immune system in organisms. They use three fighting methods to combat pathogens: phagocytosis, degranulation, and netosis. In this review, we aim to provide information about netosis.

Combination Effects of Antimicrobial Peptides.

Antimicrobial peptides (AMPs) are ancient and conserved across the tree of life. Their efficacy over evolutionary time has been largely attributed to their mechanisms of killing. Yet, the understanding of their pharmacodynamics both in vivo and in vitro is very limited. This is, however, crucial for applications of AMPs as drugs and also informs the understanding of the action of AMPs in natural immune systems. Here, we selected six different AMPs from different organisms to test their individual and combined effects in vitro. We analyzed their pharmacodynamics based on the Hill function and evaluated the interaction of combinations of two and three AMPs. Interactions of AMPs in our study were mostly synergistic, and three-AMP combinations displayed stronger synergism than two-AMP combinations. This suggests synergism to be a common phenomenon in AMP interaction. Additionally, AMPs displayed a sharp increase in killing within a narrow dose range, contrasting with those of antibiotics. We suggest that our results could lead a way toward better evaluation of AMP application in practice and shed some light on the evolutionary consequences of antimicrobial peptide interactions within the immune system of organisms.

The advantages of using traditional Chinese medicine as an adjunctive therapy in the whole course of cancer treatment instead of only terminal stage of cancer

Recent studies indicate that Traditional Chinese medicine (TCM) can play an important role in the whole course of cancer treatment such as recovery stages of post-operative, radiotherapy or chemotherapy stages instead of only terminal stage of cancer. In this review, we have summarized current evidence for using TCM as adjuvant cancer treatment in different stages of cancer lesions. Some TCMs (e.g., TJ-41, Liu-jun-zi-tang, PHY906, Coumarin, and Aescine) are capable of improving the post-operative symptoms such as fatigue, pain, appetite, diarrhea, nausea, vomiting, and lymphedema. Some TCMs (e.g., Ginseng, Huang-Qi, BanZhiLian, TJ-48, Huachansu injection, Shenqi fuzheng injection, and Kanglaite injection) in combination with chemo- or radio-therapy are capable of enhancing the efficacy of and diminishing the side effects and complications caused by chemo- and radiotherapy. Taken together, they have great advantages in terms of suppressing tumor progression, relieving surgery complications, increasing the sensitivity of chemo- and radio- therapeutics, improving an organism's immune system function, and lessening the damage caused by surgery, chemo- or radio-therapeutics. They have significant effects on relieving breast cancer-related lymphedema, reducing cancer-related fatigue and pain, improving radiation pneumonitis and gastrointestinal side effects, protecting liver function, and even ameliorating bone marrow suppression. This review of those medicines should contribute to an understanding of Chinese herbal medicines as an adjunctive therapy in the whole course of cancer treatment instead of only terminal stage of cancer, by providing useful information for development of more effective anti-cancer drugs and making more patients "survival with cancer" for a long time.

Failure of immunological cells to eradicate tumor and cancer cells: an overview

Inflammation can be broadly understood as a successive immune response of an organism's immune system towards nonnative or foreign antigens. This is a protective mechanism of the immune system, mediated by diverse immunological cells, to ensure homeostasis of an individual. Once activated, these immunological cells release a number of cytokines, chemokines, reactive oxygen species, reactive nitrogen species, histamines, prostaglandins, and other materials leading to inflammation. Tumor cells express altered proteins due to mutations of their genes, DNA modifications such as histone modification, DNA methylation, or other mechanisms of altered protein expression. The body's immunological cells actively recognize these altered proteins, now acting as tumor antigens, and eliminate the tumor cell; this is popularly known as tumor immunosurveillance. However, in unmanaged or inexorable circumstances, tumor cells escape from immunosurveillance mechanisms. This ultimately leads to the cascading events of cancer development and progression. T regulatory cells, tumor-associated macrophages, and myeloid-derived suppressor cells are pronounced cells involved in immunosuppression. These cells not only dodge the immune system's surveillance but also significantly increase the survival, proliferation, and metastasis rates of tumor cells. They hinder T cytotoxic activation by secreting inhibitory cytokines (which inhibit the antitumor activity of natural killer cells) along with dendritic cells and disrupt presentation of antigens, ultimately leading to cancer development. On their own, these cells have emerged as promising therapeutic targets in cancer immunotherapy. This review highlights some of the mechanisms by which these cells escape immunosurveillance and mediate immune suppression.

An increase in efficiency of adaptations and a weakening of organism protective reactions in the process of biological evolution

The main direction of evolution of living organisms is development of the central nervous system and sense organ, an increase of energy exchange development of homoiothermia, development of the more and more complex forms of behavior, an increase in energy expenditure in connection with an increase of the organism activity, and development of adaptation to the habitat. Such fundamental processes were subjected and have been subjected to numerous studies and discussions. However, in different animals there exist different species peculiarities of evolution of physiological functions, from which finally formed are fundamental evolutionary processes. We studied some of these specific processes by dividing them into two categories. The first category is "Increase of efficiency of adaptation" in development of biological evolution. By this term we mean development of amazing by perfection specific physiological mechanisms of adaptive character. The second category is "Weakening of protective organism reactions". By this we understand disturbance of protective mechanisms of the organism immune system, discoordination of movement of leukocytes along microvessels, the absence of efficient collateral circulation in brain and in heart, etc.

Interactions between single-chained ether phospholipids and sphingomyelin in mixed monolayers at the air/water interface—Grazing incidence X-ray diffraction and Brewster angle microscopy studies

Single-chained ether phospholipids comprise a class of both natural (PAF, lyso-PAF) and synthetic (edelfosine, ED) compounds possessing confirmed extensive biological activities. Among them ED is known to exhibit antineoplastic properties, while PAF and its lyso-precursor are lipids implicated e.g. in the functioning of organism immune system. In our study the interactions of ED, PAF and lyso-PAF with sphingomyelin (SM) being one of the main lipid found in a high concentration in membrane microdomains, like lipid rafts, were investigated in mixed monolayers at the air/water interface. The traditional Langmuir methodology was complemented with modern physicochemical techniques: Grazing incidence X-ray diffraction and Brewster angle microscopy. The investigated compounds, i.e.: platelet activating factor (PAF), (lyso-PAF) and edelfosine were selected because of their highly different physiological properties despite very similar chemical structure and evidenced membrane activity. The obtained results demonstrate that all the investigated three single-chained phospholipids cause strong modification of the model membrane properties in a concentration dependent manner. It has been proved that there are significant differences regarding the influence of the single-chained lipids on model SM membrane – in the region of low concentration, edelfosine was found to be the most effective among all the investigated compounds. The collected data shed new light onto the membrane behavior of the investigated herein biochemically active compounds, which can be of help in understanding their different biological activity and designing of new, more biocompatible drugs.

Systems analysis of eleven rodent disease models reveals an inflammatome signature and key drivers

Common inflammatome gene signatures as well as disease-specific signatures were identified by analyzing 12 expression profiling data sets derived from 9 different tissues isolated from 11 rodent inflammatory disease models. The inflammatome signature significantly overlaps with known drug targets and co-expressed gene modules linked to metabolic disorders and cancer. A large proportion of genes in this signature are tightly connected in tissue-specific Bayesian networks (BNs) built from multiple independent mouse and human cohorts. Both the inflammatome signature and the corresponding consensus BNs are highly enriched for immune response-related genes supported as causal for adiposity, adipokine, diabetes, aortic lesion, bone, muscle, and cholesterol traits, suggesting the causal nature of the inflammatome for a variety of diseases. Integration of this inflammatome signature with the BNs uncovered 151 key drivers that appeared to be more biologically important than the non-drivers in terms of their impact on disease phenotypes. The identification of this inflammatome signature, its network architecture, and key drivers not only highlights the shared etiology but also pinpoints potential targets for intervention of various common diseases.

Impacto do tratamento antirretroviral na ocorrência de macrocitose em pacientes com HIV/AIDS do município de Maringá, Estado do Paraná

AIDS is a disease caused by HIV that compromises the organism's immune system. The advent of highly active antiretroviral therapy (HAART) has promoted substantial improvement in the prognosis for this disease and in HIV/AIDS patients' quality of life. During prolonged treatment, certain hematological disorders are observed, such as anemia and macrocytosis, as well as deficiencies of micronutrient such as vitamin B12 and folic acid. The objective of this study was to correlate the presence of macrocytosis and anemia with HAART use or vitamin B12 and folic acid deficiencies. 110 HIV-positive patients were included, in three groups: HAART use with zidovudine (AZT) (group 1), HAART use without AZT (group 2) and no HAART (group 3). None of the patients in any of the three groups presented statistically significant differences relating to hemoglobin level (p = 0.584) or folic acid level (p = 0.956). Group 1 (G1) had a higher mean corpuscular volume (MCV) than G3 (p < 0.05), and group 2 (G2) had a higher volume than group 3 (G3) (p < 0.001). Vitamin B12 levels in G1 and G3 were smaller than those in G2 (p = 0.008). It was concluded that patients undergoing HAART treatment presented macrocytosis, even though this could not be correlated with the type of HAART or with vitamin B12 deficiency. However, folic acid deficiency was unrelated to either HAART or macrocytosis.

An Artificial Immune System for Frequency-Variable Air Conditioner

It is common to control the Frequency-variable air conditioner (A/C) by using PID controller. However, an arithmetic based on artificial immune system was proposed. The immune system of organism was analyzed, and an architecture of the arithmetic was designed. The A/C behaviors were expressed by antibodies, a concentration model of antibody was built, and rules of A/C behaviors could be obtained by the antibody concentration. the initial immune response arithmetic and the secondary immune response arithmetic were designed, which were used to memorized normal behaviors and detect abnormal behaviors. Experiments show that the scheme is capable of adapting to system variation. The system can obtain the stable condition with good convergence even high temperature of 45°C

COMBINED EFFECTS OF UBIQUITOUS XENOBIOTICS OF WATER ENVIRONMENT ON THE IMMUNE SYSTEM OF THE BODY

In accordance with results of researches on the combined peroral exposure of sodium nitrate, sodium nitrite and chloroform at the levels of 1, 5 and 10 of the limited permissible concentrations (LPC) for the organism immune system it was established that immunotoxic effects of studied xenobiotics have been manifested as the development of sensitization, autosensitization, injuries in the cellular and humoral immunity links, nonspecific factors of organism defence. The effects expressiveness depended on the dose, exposure duration and combinations composition. The immunotoxic effects in the animals under combined exposure of sodium nitrite, sodium nitrate and chloroform were more expressed than in the rats exposed only by nitrite-nitrate loading in the identifical doses.

Ecological immunology: The organism in context

A major challenge in integrative biology is understanding the mechanisms by which organisms regulate trade-offs among various functions competing for limiting resources. Key among these competing processes is the maintenance of health and the production of offspring. Optimizing both, given limited resources, can prove challenging. The physiological and behavioral changes that occur during reproduction have been shown to greatly influence an organism's immune system, which can have consequences for susceptibility to disease. Likewise, investing in costly immunological defenses can impair reproductive function. However, the precise nature of these physiological and behavioral interactions appears to be greatly dependent upon the environmental context in which they occur. Here we take a comparative look at interactions between the reproductive and immune systems, including current immunological approaches, and discuss how similar studies can reveal vastly disparate results. Specifically, we highlight results from the ornate tree lizard (Urosuarus ornatus) and the Siberian hamster (Phodopus sungorus) model systems, which provide an example of current research in the field. Collectively, these results emphasize the importance of resource availability and an individual's energy stores for the existence of life-history trade-offs and the efficiency of physiological processes in general. Akin to Dobzhansky's famous line, like other aspects of biology, nothing in ecoimmunology seems to make sense except in the context of an organism's environment.

Immune function in the Arctic Scallop, Chlamys islandica, following dispersed oil exposure

With the current expansion of offshore oil activities in Arctic regions, there is an urgent need to establish the potential effects of oil-related compounds on Arctic organisms. As susceptibility to growth, disease and survival is determined partly by the condition of an organism's immune system, measurement of endpoints linked to the latter system provide important early warning signals of the sub-lethal effects of exposure to contaminants. This study assessed the impact of dispersed oil exposure on immune endpoints in the Arctic Scallop Chlamys islandica, using a combination of cellular and humoral biological responses. Laboratory exposures of C. islandica to sub-lethal dispersed oil concentrations (0.06 and 0.25 mg l −1) were conducted over 15 days, followed by a 7-day recovery period in clean, filtered seawater. Cellular endpoints were significantly altered following dispersed oil exposure: haemocyte counts ( P < 0.01) and protein levels ( P < 0.01) were significantly elevated, whilst cell membrane stability ( P < 0.001) and phagocytosis ( P < 0.01) demonstrated a significant reduction. Whilst these results indicate alteration in the immune endpoints measured, this appears to be reversible upon removal of the contaminant stress. However, the impact of long-term continuous exposure and high-level acute exposure to oil is still unknown, and may have consequences for disease resistance and hence survival.

Apoptosis resistance inChlamydia-infected cells: a fate worse than death?

Chlamydia has long been studied as an intracellular pathogen causing widespread diseases. In the last three decades, the field of apoptosis has rapidly emerged, and as a consequence, research on infectious diseases in general and on Chlamydia-host interaction in particular shifted to apoptosis modulation. Ten years ago, the first paper describing the drastic inhibition of apoptosis in Chlamydia-infected cells was published. In a reversal of roles, here was a pathogen that was strongly protecting cells in an organism against destruction by the organism's immune system. Since then, numerous studies have described apoptosis inhibition by Chlamydia and the mechanisms involved, but still there is a lack of general consensus on the subject. With a section of studies even reporting the induction of cell death by Chlamydia and not its inhibition, the field became even more diverse and complicated. In this review, an attempt is made to discuss the recent findings on apoptosis modulation by chlamydial species.

Gaia living with AIDS: towards reconnecting humanity with ecosystem autopoiesis using metaphors of the immune system

This paper looks at the dynamic interface between disease, environmental degradation, and human behaviour. It is argued that the role of the ecosystem in maintaining health on a planetary scale can be likened to an organism's immune system. However, humanity's mental and emotional disconnection from these autopoietic processes is a form of ecological autism which is detrimental to the health of humans and ecosystems alike. This ecological autism is resulting in human systems acting like an autoimmune disorder; so that GAIA is living with AIDS. It is suggested that employing metaphors of the immune system to aid understanding and empathy might ameliorate this by helping humanity to realize its embeddedness within nature and to recognize the consequences of its actions. Copyright © 2006 John Wiley & Sons, Ltd.

Nitric oxide functions in the plant hypersensitive disease resistance response

Nitric oxide (NO) is a highly reactive molecule that rapidly diffuses and permeates cell membranes. In animals, NO is implicated in a number of diverse physiological processes such as neurotransmission, vascular smooth muscle relaxation, and platelet inhibition. It may have beneficial effects, for example as a messenger in immune responses, but it is also potentially toxic when the antioxidant system is weak and an excess of reactive oxygen species (ROS) accumulates. During the last few years NO as been detected also in several plant species, and the increasing number of reports on its function in plants have implicated NO as an important effector of growth, development, and defence [1]. The innate immune system of organisms as diverse as vertebrates, invertebrates, and plants shows several characteristics similar with respect to involvement of NO. In the mammalian immune system, NO cooperates with ROS to induce apoptosis of tumor cells and macrophage killing of bacteria. In plants a similar mechanism have evolved to prevent tissue invasion by pathogens. Attempted infection by an avirulent pathogen elicits a battery of defences often accompanied by collapse of challenged host cells thus delimiting the infected zone and avoiding the multiplication and spread of the pathogen. The rapid accumulation of ROS and NO through the activation of enzyme systems similar to neutrophil NADPH oxidase and nitric oxide synthase is one of the earliest events in this hypersensitive reaction (HR). Several lines of evidence suggest that death of host cells during the HR results from the activation of a cell death program, encoded by the plant genome and activated by a fine modulation of O2 -, H2O2 and NO levels [2]. Both NO and ROS are necessary to trigger host cell death (see Figure ​Figure1);1); they are also components of a highly amplified and integrated defence system that involves activation of ion fluxes, changes in protein phosphorylation patterns, extracellular pH, membrane potential, oxidative cross-linking of plant cell wall proteins, and perturbations in the level of cytosolic Ca2+ that triggers the local expression of resistance genes [3]. Figure 1 NO and H2O2 mediated plant cell death. NO, nitric oxide; NOS, nitric oxide synthase; ONOO-, peroxynitrite; H2O2, hydrogen peroxide; GPX, glutathione peroxidase; GST, glutathione S-transferase; SOD, superoxide dismutase; MAPK, mitogen-activated protein ... NO also functions independently of ROS in the induction of various defence genes including pathogenesis-related proteins and enzymes of phenylpropanoid metabolism involved in the production of lignin, antibiotics and the secondary signal salicylic acid (see Figure ​Figure2).2). The mobile nature of NO and its chemical reactivity with various cellular targets means that downstream effects of NO may be directly induced by interaction with various cellular components, like ion channels or proteins that modulates gene expression, or indirectly following interaction with signalling proteins such as protein kinases. NO signalling functions depend on its reactivity and ROS are key modulators of NO in triggering cell death, although through mechanisms different from those commonly observed in animals [4]. Figure 2 Representation of NO signalling functions during the HR. CHS, chalcone synthase; CA, cinnamic acid; Ca2+, calcium influx; cADPR, cyclic cADP ribose; cGMP, cyclic GMP; MAPK, mitogen-activated protein kinase; PAL, phenylalanine ammonia lyase; PHE, phenylalanine; ... In summary, although several hypotheses still await experimental demonstration, it is now clear that NO is an important component of plant defence systems. Much evidence supports the view that NO plays a key role in disease resistance responses. Moreover, the recent identification of a plant NOS will lead to the characterization and manipulation of mechanisms modulating NO signalling. Thus, the understanding of NO signalling functions at the biochemical, cellular and molecular levels will soon make it possible to discern several important physiological and pathological processes in plants, as has already been demonstrated in mammals.

Physiological effects of immune challenge in captive greenfinches (Carduelis chloris)

It is expected that the costs of exploiting an organism's immune system form the basis of many life-history trade-offs. However, the processes responsible for generating these costs have rarely been quantified in terms of energy expenditures and physiological rearrangements in the organism during the immune response. To determine the physiological changes caused by the immune response, we recorded various condition indices of male captive greenfinches (Carduelis chloris) 1, 4, and 8 days after immune challenge with a nonpathological antigen (sheep red blood cells; SRBC). Measured variables included estimates of total and differential leukocyte counts, serum protein concentrations and profile, serum triglyceride concentration, basal metabolic rate, body mass, spontaneous locomotory activity, and serum total antioxidant capacity. On days 4 and 8 post injection, immune-challenged greenfinches significantly reduced their spontaneous locomotory activity, which suggests a switch to energy conservation. Fourteen hours after injection of SRBC, a transient increase in serum beta-globulin concentration was recorded, indicating an acute-phase response to the antigen. None of the other condition indices was affected by the treatment, which suggests that when birds maintained on an affluent feeding regimen in captivity mounted an immune response against SRBC, they did not incur any serious physiological impact.

The innate immune response to bacterial flagellin is mediated by Toll-like receptor 5.

The innate immune system recognizes pathogen-associated molecular patterns (PAMPs) that are expressed on infectious agents, but not on the host. Toll-like receptors (TLRs) recognize PAMPs and mediate the production of cytokines necessary for the development of effective immunity. Flagellin, a principal component of bacterial flagella, is a virulence factor that is recognized by the innate immune system in organisms as diverse as flies, plants and mammals. Here we report that mammalian TLR5 recognizes bacterial flagellin from both Gram-positive and Gram-negative bacteria, and that activation of the receptor mobilizes the nuclear factor NF-kappaB and stimulates tumour necrosis factor-alpha production. TLR5-stimulating activity was purified from Listeria monocytogenes culture supernatants and identified as flagellin by tandem mass spectrometry. Expression of L. monocytogenes flagellin in non-flagellated Escherichia coli conferred on the bacterium the ability to activate TLR5, whereas deletion of the flagellin genes from Salmonella typhimurium abrogated TLR5-stimulating activity. All known TLRs signal through the adaptor protein MyD88. Mice challenged with bacterial flagellin rapidly produced systemic interleukin-6, whereas MyD88-null mice did not respond to flagellin. Our data suggest that TLR5, a member of the evolutionarily conserved Toll-like receptor family, has evolved to permit mammals specifically to detect flagellated bacterial pathogens.

Stress, opioid peptides, the immune system, and cancer

Our results indicate that a particular form of footshock stress can suppress immune function in rats and decrease their resistance to tumor challenge. These effects appear to be mediated by opioid peptides released by stress, and they can be mimicked by high doses of morphine given systemically or by a vastly smaller dose delivered intracerebroventricularly. Such findings fit well into the emerging field of behavioral neuroimmunology and reinforce continuing efforts to elucidate the neural and neurohumoral mechanisms by which the environment can affect the organism's immune system.