A role for Leukotriene B4 in the induction of airway hyper-responsiveness was explored through the use of transgenic mice deficient in the BLT1 receptor for LTB4 . Ovalbumin challenge of sensitized wild-type mice resulted in the usual features of experimental asthma, including goblet cell hyperplasia, hyper-responsiveness to inhaled methacholine and elevated BAL fluid concentrations of the Th2 cytokine IL-13. In contrast, BLT1 –/– mice (i.e. genetically modified mice lacking the gene coding for the BLT1 receptor) exhibited significantly lower responses. BLT1 –/– mice also exhibited lower numbers of IL-13-positive T lymphocytes of both the helper (CD4 T Cells) and cytotoxic/suppressor (CD8 + ) types. (more…)
Vascular Endothelial Growth Factor (VEGF), originally described as a vascular permeability factor generating tissue oedema, has be ...
Airway hyper-responsiveness in asthma may involve smooth muscle growth, a manifestation of airway remodelling. The involvement ...
IgE plays an important role in allergic asthma. Reducing IgE in the airway mucosa should reduce airway inflammation. Omalizumab has ...
Some features seem to be common to severe asthma and Chronic Obstructive Pulmonary Disease with reversibility of airflow limita ...
Antihistamines have been shown to be effective in seasonal allergic rhinitis and chronic idiopathic urticaria. They improve qua ...
Treg cells or regulatory T cells constitute a large population of cellular infiltrate in atopic/allergic inflammation and a dysregulated immune response appears to be an important pathogenetic factor. Cardinal events during allergic inflammation can be classified as activation, organ-selective homing, survival and reactivation, and effector functions of immune system cells. T cells are activated by aeroallergens, food antigens, autoantigens, and bacterial exotoxins superantigens in allergic inflammation. They are under the influence of the skin, lung, or nose-related chemokine network and show organ-selective homing. (more…)
Allergen-specific immunotherapy is highly effective in the treatment of IgE-mediated allergy diseases such as rhinitis, conjunc ...
The induction of immune tolerance and specific immune suppression are essential processes in the control of immune responses. R ...
The intracellular forkhead winged transcription factor Foxp3 (forkhead box P3) appears to be specifically expressed by naturall ...
An emerging concept is that pro-inflammatory signals lead to loss of Regulatory T Cells (Treg) function. Pasare and Medzhitov ( ...
Regulatory T cells Treg (picture above) is the existence of suppressor cells, which limit ongoing immune responses and prevent ...
Allergen-specific immunotherapy is highly effective in the treatment of IgE-mediated allergy diseases such as rhinitis, conjunctivitis, asthma, and venom allergy hypersensitivity. It is the only treatment that leads to lifelong tolerance against previously disease-causing allergens due to restoration of the normal immunity. (more…)
Allergen-specific immunotherapy aims to correct the underlying immune imbalance associated with specific immunotherapy allergic rhi ...
Histamine is a low-molecular-weight monoamine that binds to four different G-protein-coupled receptors, and has recently been d ...
The precise mechanisms underlying the effects of Specific Immunotherapy are not well understood but several studies have shown ...
Treg cells or regulatory T cells constitute a large population of cellular infiltrate in atopic/allergic inflammation and a dys ...
The immunologic mechanisms of sublingual immunotherapy are less established. In Cochrane analysis, the authors concluded that t ...
The intracellular forkhead winged transcription factor Foxp3 (forkhead box P3) appears to be specifically expressed by naturally occurring Treg cells, particularly in mice, although in humans there is evidence of upregulation of Foxp3 in all T cells on activation. Foxp3 is required for the development and function of naturally occurring regulatory t cells (treg) and expression is sufficient to convert non-regulatory CD4+CD25T cells into cells with regulatory activity. Conversion of peripheral CD4+CD25 naive T cells to Foxp3+CD4+CD25 foxp3+ Treg cells can be induced by TGF-ß. In a murine asthma model, these TGF-ß-induced Treg prevented house-dust mite-induced allergic pathogenesis or infection pathogenesis in lungs. A single independent report has suggested that IL-4 and IL-13 also induce Foxp3+CD25+ Treg from CD4+CD25precursors. (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 induction of immune tolerance and specific immune suppression are essential processes in the control of immune responses. R ...
Allergen-specific immunotherapy is highly effective in the treatment of IgE-mediated allergy diseases such as rhinitis, conjunc ...
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 Ras-dependent pathway can be triggered by a variety of cytokine receptors, as well as by certain adhesion molecules and by many other surface receptors when they contact appropriate ligands. Signaling in this pathway can be initiated by cytosolic proteins called Src-family kinases, so named because they bear regions of sequence homology to the oncoprotein Src. These Src-like kinases contain specialized protein domains, termed SH2 domains (for Src-homology region 2), that enable them to bind other proteins containing phosphorylated tyrosine residues. When a cytokine receptor binds ligand, subunits of the receptor become phosphorylated and can immediately be bound by a Src-family kinase. (more…)
Perhaps the most exciting recent advance in the cytokine signaling field has been the elucidation of the Jak/Stat pathway. The ...
The overlapping functions of cytokines largely reflect the properties of the cell surface receptors to which they bind. All cyt ...
Although it is commonly imagined that hematopoiesis takes place in a liquid environment resembling the blood, with progenitors resp ...
The process by which blood cells grow, divide, and differentiate in the bone marrow is called hematopoiesis. Three general cl ...
Our understanding of hematopoiesis has advanced greatly in recent years with the isolation and characterization of hematopoietic st ...
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: • ...
The immune system consists of proteins, cells and organs that are concerned with defense of the individual, primarily against the threat of disease caused by infectious organisms. An infectious organism that causes disease is called a pathogen and the individual (person or animal) that is infected by a pathogen is called the host. Not all infectious organisms cause disease and some are actually beneficial, for example bacteria living in the gut help to digest certain foods. Infectious organisms that help the host are called commensalism organisms. (more…)
The final stage of the disease process (although it may not be the final stage of the infection) is the actual production of di ...
There are thousands of components to the immune system, and during the course of learning about some of these it can appear tha ...
Serodiagnosis of bacterial diseases is of value only in specific circumstances. IgG antibody is long-lived, and its presence, a ...
Routes by which infectious organisms gain entry into the body include the skin, respiratory tract, gastro-intestinal (GI) tract ...
Allergic Reactions For daily life, of course we need our immune system. Without having immune system, we could not survive ...
The mediators released by mast cells and basophils can be grouped into two categories:
(1) preformed substances contained within granules and
(2) newly generated chemicals synthesized following cellular activation.
These mediators comprise the effector function of the mast cell. Together they are able to increase vascular permeability, dilate vessels, cause bronchospasm, contract smooth muscle, and summon inflammatory cells. Few cells in the body produce compounds with such a large and varied spectrum of activity. (more…)
The response to injury usually begins with dilatation of small blood vessels in and around the injured site (figure bellow). Th ...
The cysteinyl leukotrienes (LTC 4 , LTD 4 and LTE 4 ) are lipid mediators produced from an arachidonic acid precursor following ...
The precise mechanisms underlying the effects of Specific Immunotherapy are not well understood but several studies have shown ...
Normally present at very low levels in plasma, antibodies of the immunoglobulin E (IgE) isotype were first discovered in 1967, ...
The oral allergy syndrome is difficult to detect. Common allergy tests to examine allergy are using extracts only in skin scrat ...