Complement Cascade: Antibodies and Phagocytic Cells to Clear Pathogens

complement cascade
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…)

Inflammation Mediators and Vascular Responses to Injury or Infection

inflmmation responses
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…)

Antimicrobial Enzymes and Binding Proteins

antimicrobial enzymes
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…)

Soluble CD14 in Breast Milk: Atopic Dermatitis & Asthma In Early Childhood

Soluble CD14 Concentration
Breast milk contains a variety of bioactive substances, among them soluble CD14 (sCD14), which plays an important role in innate immunity. The authors analysed data of a large prospective birth cohort study to examine the determinants of sCD14 in breast milk, and investigated whether breast-feeding practice and sCD14 concentrations in breast milk are determinants of the risk of Atopic Dermatitis and asthma in children. Eight hundred and three mothers and their newborn infants were included in this analysis. (more…)

Antigen-Specific Cd4 T Cells Drive Airways Smooth Muscle Remodeling In Experimental Asthma

Cd4 T Cells
Airway hyper-responsiveness in asthma may involve smooth muscle growth, a manifestation of airway remodelling. The involvement of inflammatory cells in the induction of airway smooth muscle growth was studied in vivo and ex vivo in a brown Norway rat model of asthma. Transfer of CD4 + T lymphocytes from ovalbuminsensitized animals induced an increase in airway smooth muscle mass in naive animals upon repeated ovalbumin challenge. Ex vivo, coculture of antigen-stimulated CD4 + T cells and airway smooth muscle cells led to myocyte proliferation and prolonged T-cell survival. (more…)

Impact of Disease on Innate Immunity

While our primary concern is the impact that the innate immune system has on allergic disease, it is essential to recognize that allergic disease also impacts on the function- ing of the innate immune system. In part this is through treatment, since immunosuppressive therapies inevitably contribute to impairment of immunity at the levels of the innate and adaptive systems. (more…)