Histamine is a low-molecular-weight monoamine that binds to four different G-protein-coupled receptors, and has recently been demonstrated to regulate several essential events in the immune response. The histamine receptor type 2 (HR2) is coupled to adenylate cyclase and studies in different species and several human cells have demonstrated that inhibition of characteristic features of the cells by primarily cAMP formation dominates in HR2-dependent effects of histamine. (more…)
Allergen-specific immunotherapy is highly effective in the treatment of IgE-mediated allergy diseases such as rhinitis, conjunc ...
The precise mechanisms underlying the effects of Specific Immunotherapy are not well understood but several studies have shown ...
The specific treatment of allergy has previously relied upon allergen avoidance and sublingual immunotherapy. These approaches have ...
Allergen-specific immunotherapy aims to correct the underlying immune imbalance associated with specific immunotherapy allergic rhi ...
The immunologic mechanisms of sublingual immunotherapy are less established. In Cochrane analysis, the authors concluded that t ...
The induction of immune tolerance and specific immune suppression are essential processes in the control of immune responses. Regulatory T cells (Treg) play a central role in immune control in the periphery. Two broad categories of Treg have been described: naturally occurring Treg that are present in all individuals and antigen-induced Treg that secrete inhibitory cytokines such as interleukin (IL)-10 and/or transforming growth factor (TGF)-ß. (more…)
Regulatory T cells Treg (picture above) is the existence of suppressor cells, which limit ongoing immune responses and prevent ...
An emerging concept is that pro-inflammatory signals lead to loss of Regulatory T Cells (Treg) function. Pasare and Medzhitov ( ...
Treg cells or regulatory T cells constitute a large population of cellular infiltrate in atopic/allergic inflammation and a dys ...
The intracellular forkhead winged transcription factor Foxp3 (forkhead box P3) appears to be specifically expressed by naturall ...
Allergen-specific immunotherapy is highly effective in the treatment of IgE-mediated allergy diseases such as rhinitis, conjunc ...
The response to injury usually begins with dilatation of small blood vessels in and around the injured site (figure bellow). This response (called vasodilatation) results from relaxation of smooth muscle in the vascular walls. It can begin within seconds after an acute injury or develop over hours or days of low-grade irritation or infection. Vasodilatation initially results in increased blood flow through arterioles, capillaries, and venules of the affected region, leading to redness (erythema) and warmth. As the vessels dilate, endothelial cells lining some of the vessels actively retract away from one another to create temporary, microscopic gaps in the endothelial lining. Endothelial retraction occurs only in the smallest venules (often called postcapillary venules), which are thin-walled vessels with lumenal diameters of 20 - 60 µm. (more…)
Some of the immediate sequelae of injury are uncomfortably familiar: Soon after an injury occurs, the affected site and its sur ...
Acute inflammatory response constitute the first line of defense against infection pathogenesis and how immune system works as ...
Once it is tethered onto the venule wall, the neutrophil or other leukocyte comes into contact with a wide variety of inflammatory ...
Neutrophils make up an army of more-or-less identical circulating phagocytes that are poised to respond quickly and in vast numbers ...
The airway circulation has many potential roles in asthma. The vasculature has a major influence on upper airway patency in nasal i ...
With the exception of complement protein C3, most soluble mediators of innate immunity are found in relatively small amounts in the serum under normal conditions. The concentrations of several of these proteins, however, can increase as much as 1000-fold during serious infections or other crises, as part of a coordinated protective reaction called the acute-phase response. In this response, the liver temporarily increases its synthesis of more than 30 different serum proteins, often called acute-phase proteins (Table bellow). Many of these, such as complement factors C3 and B, MBL, LBP, C-reactive protein, and serum amyloid protein P, participate in antimicrobial defense. (more…)
Acute phase proteins are plasma proteins, the synthesis and the circulating concentrations of which are adaptively regulated in res ...
Most acute phase proteins are synthesized in the liver, although the genes for some are also expressed in cells and tissues els ...
There is considerable diversity among acute phase proteins with respect to the concentrations attained, their structures, and their ...
Acute phase proteins and the acute phase response in general arc stably conserved in evolution and are universal within each specie ...
An especially elaborate and important type of innate antimicrobial enzymes defense is provided by a group of serum proteins tha ...
An especially elaborate and important type of innate antimicrobial enzymes defense is provided by a group of serum proteins that together make up the complement cascade pathway. This group comprises more than two dozen different liver-and macrophage-derived proteins, called complement factors or components, most of which normally circulate in the form of proenzymes that have latent protease activity. As a rule, each of the proteases becomes active when proteolytically cleaved and will then catalyze cleavage and activation of a different complement component. (more…)
Innate immune responses are seen in a very broad range of tissues. Indeed, the Toll-like receptors (TLRs, one of the most important ...
A few of the best known humoral effectors of innate immunity are listed in Table 1 bellow, along with the types of target molec ...
With the exception of complement protein C3, most soluble mediators of innate immunity are found in relatively small amounts in ...
Some of the immediate sequelae of injury are uncomfortably familiar: Soon after an injury occurs, the affected site and its sur ...
Bacteria cause allergic disease because of toxicity, invasiveness, immunopathology, or lends of these three mechanisms. Thus much ...
Other humoral effectors and humoral factors have the ability to lyse microorganisms directly. The best studied of these are a class of small peptide antibiotics known as defensins, which in their active forms are all roughly 30 amino acids long (3,5 kilodaltons), positively charged, and protease-resistant. Each also has three internal disulfide bonds. They are classified as either α or β defensins based on the arrangement of the disulfides, but both classes have nearly the same compact, folded structure consisting of three strands of antiparallel β-pleated sheets. (more…)
Contact of pathogens with the innate immune system will most frequently occur at epithelia, and the biology of the airway epitheliu ...
The body's innate resistance to many pathogens is provided by enzymes and other proteins in the blood and tissue fluids. These ...
Innate immune responses are seen in a very broad range of tissues. Indeed, the Toll-like receptors (TLRs, one of the most important ...
While our primary concern is the impact that the innate immune system has on allergic disease, it is essential to recognize that al ...
A few of the best known humoral effectors of innate immunity are listed in Table 1 bellow, along with the types of target molec ...
Some of the immediate sequelae of injury are uncomfortably familiar: Soon after an injury occurs, the affected site and its surrounding tissues become reddened, warm, swollen, and painful. These four signs which are probably the most useful and ubiquitous diagnostic clues in all of clinical medicine are hallmarks of acute inflammation, the body’s initial physiologic reaction to tissue distress. In its simplest form, inflammation is a response carried out by blood vessels and by the endothelial cells that line them. (more…)
The response to injury usually begins with dilatation of small blood vessels in and around the injured site (figure bellow). Th ...
Once it is tethered onto the venule wall, the neutrophil or other leukocyte comes into contact with a wide variety of inflammatory ...
Acute inflammatory response constitute the first line of defense against infection pathogenesis and how immune system works as ...
Nearly all tissues, organs, and serosal cavities harbor a population of resident phagocytes. Most contain only a diffuse scattering ...
Innate immune responses are seen in a very broad range of tissues. Indeed, the Toll-like receptors (TLRs, one of the most important ...
A few of the best known humoral effectors of innate immunity are listed in Table 1 bellow, along with the types of target molecules they recognize. Some are enzymes that can directly injure or kill microbial pathogens. An example is lysozyme, an endoglycosidase found in human saliva, mucus, tears, and other secretions, which attacks the protective cell wall encasing every bacterial cell. Lysozyme acts by digesting the peptidoglycan meshwork formed by long carbohydrate chains of alternating N-acetylmuramic acid and N-acetylglucosamine residues, crosslinked covalently by short oligopeptide sidechains which is a major constituent of all bacterial cell walls but is not found in mammalian tissues. (more…)
An especially elaborate and important type of innate antimicrobial enzymes defense is provided by a group of serum proteins tha ...
One especially favored target for immune recognition is bacterial lipopolysaccharide (LPS). This macromolecule is found only in ...
The body's innate resistance to many pathogens is provided by enzymes and other proteins in the blood and tissue fluids. These ...
With the exception of complement protein C3, most soluble mediators of innate immunity are found in relatively small amounts in ...
Although it is commonly imagined that hematopoiesis takes place in a liquid environment resembling the blood, with progenitors resp ...
The body’s innate resistance to many pathogens is provided by enzymes and other proteins in the blood and tissue fluids. These proteins are the effectors (ie, the active agents) of humoral innate immunity, and they have features in common with one another that are also characteristics of the innate immune system as a whole. First, these proteins are continually expressed throughout life, regardless of whether or not their protective effects are needed at a given moment. Second, although many of these proteins can be produced in higher quantities in times of need, their intrinsic properties (eg, substrate specificity and ige binding affinity) never change: The characteristics of these proteins have been shaped by evolution, are genetically determined, and are fixed at birth, so that they do not vary during an individual’s lifetime. (more…)
A few of the best known humoral effectors of innate immunity are listed in Table 1 bellow, along with the types of target molec ...
Contact of pathogens with the innate immune system will most frequently occur at epithelia, and the biology of the airway epitheliu ...
Innate immune responses are seen in a very broad range of tissues. Indeed, the Toll-like receptors (TLRs, one of the most important ...
An especially elaborate and important type of innate antimicrobial enzymes defense is provided by a group of serum proteins tha ...
Other humoral effectors and humoral factors have the ability to lyse microorganisms directly. The best studied of these are a c ...
The final stage of the disease process (although it may not be the final stage of the infection) is the actual production of disease. Many microorganisms live in or on the body without causing disease. These organisms are called commensal organisms and may be beneficial to the host: the production of lactic and lactobacilli proprionic acidophilus in the vagina inhibits the growth of many other bacteria and many commensal organisms compete with pathogens for ‘living space’ in the gut. Microbial pathogens differ in that they cause dis- ease by one or more mechanisms like picture bellow. These include the following: (more…)
There are thousands of components to the immune system, and during the course of learning about some of these it can appear tha ...
Most initial infections are local, i.e. the infectious agent gains entry to the body at a single site, e.g. via an insect bite ...
There are several pathogen types that can cause disease include many groups of single-celled microorganisms and larger multicel ...
Routes by which infectious organisms gain entry into the body include the skin, respiratory tract, gastro-intestinal (GI) tract ...
Exotoxins are secreted products, usually of bacteria but sometimes protozoa and fungi. They can act in a number of ways: • ...