The role of the immune system is simple yet challenging: to eliminate pathogenic agents. The immune system contains nonspecific and specific components; that is, some constituents act without precise recognition of the target, others have exquisite specificity. Regulation of the immune response and maintenance of tolerance to self are critical ...

Immunological measures are increasingly being applied to ecological and evolutionary studies of wild vertebrates, yet frequently it is not clear how condition and environmental factors correlate with various immune parameters. We used mixed-model ANOVA to examine the effects of several measures of condition (both morphological and physiological) and environmental factors ...

Human cytomegalovirus (HCMV) (HHV-5, a beta-herpesvirus) causes the vast majority of infection-related congenital birth defects, and can trigger severe disease in immune suppressed individuals. The high prevalence of societal infection, the establishment of lifelong persistence and the growing number of immune-related diseases where HCMV is touted as a potential promoter ...

Peptidoglycan recognition proteins (PGRPs or PGLYRPs) are innate immunity proteins that are conserved from insects to mammals, recognize bacterial peptidoglycan, and function in antibacterial immunity and inflammation. Mammals have four PGRPs - PGLYRP1, PGLYRP2, PGLYRP3, and PGLYRP4. They are secreted proteins expressed in polymorphonuclear leukocytes (PGLYRP1), liver (PGLYRP2), or on ...

How endosymbiotic bacteria cope with host insect immunity is poorly understood. Here we report previously unknown aspects of immunity-mediated interactions between male-killing/non-male-killing spiroplasmas and Drosophila host. The male-killing spiroplasma tended to reduce constitutive expression levels of some antimicrobial peptide genes, while the non-male-killing spiroplasma did not. In mutant flies whose ...

Autophagy is a conserved catabolic stress response pathway that is increasingly recognized as an important component of both innate and acquired immunity to pathogens. The activation of autophagy during infection not only provides cell-autonomous protection through lysosomal degradation of invading pathogens (xenophagy), but also regulates signaling by other innate immune ...

Host protection against fungi depends on intact innate and adaptive immune responses. Consistently, fungal infections can cause systemic life-threatening diseases in immunocomprimised individuals, suffering e.g. from cancer or AIDS. Recent work has uncovered essential roles for the spleen tyrosine kinase (SYK) and the cytosolic NLRP3 inflammasome for Interleukin-1beta (IL-1beta) production ...

INTRODUCTION: The innate immune system depends on molecules collectively known as pattern recognition receptors (PRRs) to survey the extracellular space and the cytoplasm for the presence of dangerous pathogens, pathogen-derived molecules, or even self-derived molecular danger signals, which arise from tissue damage. Absent in melanoma 2 (AIM2) is a newly ...

Elafin and secretory leukocyte protease inhibitor (SLPI) are pleiotropic molecules chiefly synthesized at the mucosal surface that have a fundamental role in the surveillance against microbial infections. Their initial discovery as anti-proteases present in the inflammatory milieu in chronic pathologies such as those of the lung suggested that they may ...

BACKGROUND: Autism is a complex polygenic neurodevelopmental disorder characterized by deficits in communication and social interactions as well as specific stereotypical behaviors. Both genetic and environmental factors appear to contribute to the pathogenesis of autism. Accumulating data including changes in immune responses, linkage to major histocompatibility complex antigens, and the ...

Glycerophospholipids represent a common class of lipids critically important for integrity of cellular membranes. Oxidation of esterified unsaturated fatty acids dramatically changes biological activities of phospholipids. Apart from impairment of their structural function, oxidation makes oxidized phospholipids (OxPLs) markers of "modified-self" type that are recognized by soluble and cell-associated receptors ...

The human pathogenic fungus Candida albicans is the predominant cause of both superficial and invasive forms of candidiasis. Clinical observations indicate that mucocutaneous Candida infections are commonly associated with defective cell-mediated immune responses. The importance of the innate immune system as a first-line defense against pathogenic challenge has long been ...

The mechanisms by which the immune system responds to an infection or disease depend on a complex interplay between the elements of innate and adaptive immunity. While most of the focus so far has been on the innate instruction of the adaptive immune responses, considerable evidence now suggests an equally ...

Interleukin-17 (IL-17) and IL-17-producing cells have been shown to play important roles in inflammation and the immune response. IL-17 is believed to be mainly produced by T helper 17 (Th17) cells, a unique helper T-cell subset different from Th1 and Th2 cells. Other subsets of T cells such as gammadeltaT ...

Cell-surface pattern recognition receptors (PRRs) are key components of the innate immune response in animals and plants. These receptors typically carry or associate with non-RD kinases to control early events of innate immunity signaling. Despite their importance, the mode of regulation of PRRs is largely unknown. Here we show that ...

Type 1 diabetes mellitus is an autoimmune disease caused by the immune-mediated destruction of insulin-producing pancreatic beta cells occurring in genetically predisposed individuals, with consequent hyperglycemia and serious chronic complications. Studies in man and in experimental animal models have shown that both innate and adaptive immune responses participate to disease ...

DJ-1 is a neuroprotective gene mutated in recessive Parkinson's disease (PD). In addition to direct protective functions in neurons, DJ-1 regulates neuroinflammatory signaling in primary mouse brain astrocytes. To assess the influence of DJ-1 on innate immunity signaling in vivo, we have generated djr-1 knockout Caenorhabditis elegans. When grown on ...

Dietary supplementation with nutrients that have physiologic effects on immune function has been shown to be beneficial in subsets of patients with surgical and medical critical illness. However, several meta-analyses have suggested potential harm when immune nutrients are used inappropriately. This has led to concern among clinicians that in turn ...

How the innate immune system functions to defend insects from viruses is an emerging field of study. We examined the impact of melanized encapsulation, a component of innate immunity that integrates both cellular and humoral immune responses, on the success of the baculovirus Lymantria dispar multiple nucleocapsid nucleopolyhedrovirus (LdMNPV) in ...

The peripheral immune system can promote either immunity or tolerance when presented with new antigens. Current knowledge withholds that populations of suppressor or regulatory T cells (T(reg) cells) constitute a pivotal mechanism of immunological tolerance. The potential role of malfunctioning T(reg) cells in chronic inflammatory immune and auto-immune diseases is ...

Microbial nucleic acids are potent inducers of innate immune response--the first line of host defense against microbes. It is known that double-stranded (ds) DNA triggers the expression of type I interferons (IFNs) and IFN-inducible genes resulting in the establishment of an antimicrobial environment. However, the regulatory mechanisms underlying the signaling ...

INTRODUCTION: The innate immune system orchestrates inflammatory responses to microorganisms or danger-associated molecular patterns generated, for example, by the deposition of uric acid in the joints of gout patients. The innate immune system comprises multiple germ-line encoded receptors, of which the nucleotide-binding domain and leucine-rich repeat containing receptors (NLRs) are ...

Type 1 diabetes (T1D) is an autoimmune disease typically believed to result from malfunctions in adaptive immune response signaling which result in activation of self-reactive T cells. However, recent research has indicated components of the innate immune response as having a key role in the initiation of the autoimmune process ...

Adaptive immunity has been defined, principally through studies of avian and mammalian species, as the ability to mount specific immune responses to a virtually unlimited variety of antigens. A key feature of an adaptive immune system is the ability to remember previous encounters with antigens and to achieve a more ...

Myelodysplastic syndromes (MDS) are heterogeneous clonal hematologic malignancies characterized by cytopenias caused by ineffective hematopoiesis and propensity to progress to acute myeloid leukemia. Innate immunity provides immediate protection against pathogens by coordinating activation of signaling pathways in immune cells. Given the prominent role of the innate immune pathway in regulating ...

Plants rely exclusively upon mechanisms of innate immunity. Current concepts of the plant innate immune system are based largely on two forms of immunity that engage distinct classes of immune receptors. These receptors enable the recognition of non-self structures that are either conserved between members of a microbial class or ...

Innate immunity in Caenorhabditis elegans requires a conserved PMK-1 p38 mitogen-activated protein kinase (MAPK) pathway that regulates the basal and pathogen-induced expression of immune effectors. The mechanisms by which PMK-1 p38 MAPK regulates the transcriptional activation of the C. elegans immune response have not been identified. Furthermore, in mammalian systems ...

All metazoans possess innate immune defence system whereas parameters of the adaptive immune system make their first appearance in the gnathostomata, the jawed vertebrates. Fish are therefore the first animal phyla to possess both an innate and adaptive immune system making them very interesting as regards developmental studies of the ...

Pathogen diversification can alter infection virulence, which in turn drives the evolution of host immune diversification, resulting in countermeasures for survival in this arms race. Somatic recombination of the immunoglobulin gene family members is a very effective mechanism to diversify antibodies and T-cell receptors that function in the adaptive immune ...

Trypanosoma cruzi infection is a major public health problem in Latin America. The host innate immune system plays a pivotal role in the recognition of T. cruzi infection and the subsequent development of adaptive immunity. In this review, we focus on the TLR-dependent and -independent innate immune responses to T. ...

INTRODUCTION: Cytokine production by innate immune cells is initiated by signaling downstream of pattern recognition receptors, including Toll-like receptors. DISCUSSION: A subset of cytokines, including IL-1beta and IL-18, require post-translational proteolysis before secretion, which provides a second mechanism of regulation. This proteolysis is dependent upon caspase 1, which is activated ...

Antimicrobial peptides (AMPs) are ancient and essential elements of the host defense system, which are found in a wide variety of species. They show antimicrobial activity against a wide range of pathogenic microorganisms. In addition, AMPs are expressed by different immune cells and have a important function in host innate ...

Inflammasomes are molecular platforms activated upon cellular infection or stress that trigger the maturation of proinflammatory cytokines such as interleukin-1beta to engage innate immune defenses. Strong associations between dysregulated inflammasome activity and human heritable and acquired inflammatory diseases highlight the importance this pathway in tailoring immune responses. Here, we comprehensively ...

Regulatory T cells (T(reg)) control an array of immune responses both in the context of various polarized settings as well as in distinct microenvironments. This implies that maintenance of peripheral homeostasis relies on the capacity of T(reg) to appropriately adapt to these defined settings while sustaining a regulatory program in ...

It has been speculated that the rise of the adaptive immune system in jawed vertebrates some 400 million years ago gave them a superior protection to detect and defend against pathogens that became more elusive and/or virulent to the host that had only innate immune system. First, this line of ...

Epithelial cells provide the first line of defense against mucosal pathogens; however, their coordination with innate and adaptive immune cells is not well understood. Using mice with conditional gene deficiencies, we found that lymphotoxin (LT) from innate cells expressing transcription factor RORgammat, but not from adaptive T and B cells, ...

Constant exposure to a wide variety of microbial pathogens represents a major challenge for our skin. Antimicrobial peptides (AMPs) are mediators of cutaneous innate immunity and protect primarily against microbial infections. Cathelicidins were among the first AMPs identified in human skin and recent evidence suggests that they exert a dual ...

Pentraxins are a superfamily of conserved proteins involved in the acute-phase response and innate immunity. Pentraxin 3 (PTX3), a prototypical member of the long pentraxin subfamily, is a key component of the humoral arm of innate immunity that is essential for resistance to certain pathogens. A regulatory role for pentraxins ...

Innate immunity provides the first line of defence against invading pathogens and provides important cues for the development of adaptive immunity. Type-2 immunity-responsible for protective immune responses to helminth parasites and the underlying cause of the pathogenesis of allergic asthma-consists of responses dominated by the cardinal type-2 cytokines interleukin (IL)4, ...

Human cells might display mechanisms counteracting infections by porcine endogenous retroviruses (PERV) in the course of pig-to-human xenotransplantation. Mammals have developed a number of protective strategies against viruses, including an intracellular antiretroviral defense as part of the innate immunity. In addition to the conventional innate and acquired immune responses an ...

Activation of the host innate immune response after systemic administration of adenoviral vectors constitutes a principal impediment to successful clinical gene replacement therapies. Although helper-dependent adenoviruses (HDAds) lack all viral functional genes, systemic administration of a high dose of HDAd still elicits a potent innate immune response in host animals. ...

In 2009, reports on basic and clinical immunology had an increased focus on human disease mechanisms and management. The molecular pathogenesis of familial angioedema associated with estrogen was further explored to find possible factors affecting severity, including polymorphisms in enzymes and receptors related to bradykinin pathways. A placebo-controlled clinical trial ...

Immune responses play a critical role in protection from, and resolution of, cryptosporidiosis. However, the nature of these responses, particularly in humans, is not completely understood. Both innate and adaptive immune responses are important. Innate immune responses may be mediated by Toll-like receptor pathways, antimicrobial peptides, prostaglandins, mannose-binding lectin, cytokines ...

Through pattern recognition receptors the innate immune system detects disruption of the normal function of the organism and initiates responses directed at correcting these derangements. Cellular damage from microbial or non-microbial insults causes the activation of nucleotide-binding domain leucine-rich repeat containing receptors in multiprotein complexes called inflammasomes. Here we discuss ...

Reptiles are ectothermic amniotes, providing the key link between ectothermic anamniotic fishes and amphibians, and endothermic amniotic birds and mammals. A greater understanding of reptilian immunity will provide important insights into the evolutionary history of vertebrate immunity as well as the growing field of eco-immunology. Like mammals, reptile immunity is ...

The innate immune response is the first line of host defense against infections. This system employs a number of different types of cells, which in turn activate different sets of genes. Microarray studies of human and mouse cells infected with various pathogens identified hundreds of differentially expressed genes. However, combining ...

INTRODUCTION: MicroRNA are emerging as key regulators of the development and function of adaptive immunity. These 19-24 nucleotide regulatory RNA molecules have essential roles in multiple faucets of adaptive immunity, from regulating the development of the key cellular players to the activation and function in immune responses. DISCUSSION: MicroRNA are ...

Understanding heterogeneity in adaptive immune responses is essential to dissect pathways of memory B and T cell differentiation and to define correlates of protective immunity. Traditionally, immunologists have deconvoluted this heterogeneity with flow cytometry--with combinations of markers to define signatures that represent specific lineages, differentiation states, and functions. Genome-scale technologies ...

The detection and compensatory response to the accumulation of unfolded proteins in the endoplasmic reticulum (ER), termed the unfolded protein response (UPR), represents a conserved cellular homeostatic mechanism with important roles in normal development and in the pathogenesis of disease. The IRE1-XBP1/Hac1 pathway is a major branch of the UPR ...

Recent studies have shown that both innate and adaptive immunity contribute to hypertension. Inflammatory cells, including macrophages and T cells accumulate in the vessel wall, particularly in the perivascular fat, and in the kidney of hypertensive animals. Mice lacking lymphocytes are resistant to the development of hypertension, and adoptive transfer ...