Binding Lectin : An Essential Component Of The Innate Immune System Essay

Lipopolysaccharide (LPS, endotoxin) is a component of the membrane of Gram-negative bacteria that causes sepsis [20]. Bacterial toxins play a pivotal role in the pathophysiology of sepsis and mechanisms of multiple organ system dysfunction. However, the literature illustrates that no single mediator/system/pathway/pathogen drives the pathophysiology of sepsis [21]. Current knowledge on sepsis pathogenesis [1, 22-26] includes infection development and interaction with the host before bacteria enter the bloodstream. Actually, the mechanisms of host defense in extravasal compartment (local immunity) is different from the mechanisms of intravasal (bloodstream) defenense because extravasal defense is provided mainly by leukocytes whereas intravasal cellular defense is fulfilled by erythrocytes. The humoral immunity events of pre-septic stage affect bacteremic (septic) stage and interfere with the study of sepsis “per se.” As a result, the pathogenesis and pathophysiology of some pivotal aspects of sepsis remain

4. Complement (p.458)(complement system): Set of serum proteins designated numerically according to their order of discovery

Second, in order to further confirm the information about characteristics and function of the targeting protein that we have

Instead of being recognized and attacked by T cells, bacteria are recognized and attacked by complement proteins. “Complement proteins assist in bacterial killing via three pathways, the classical complement pathway, the alternative complement pathway or the lectin pathway. The first steps of the classical complement pathway require the binding of antibodies to the surface of the target bacterium” (Immune, 2016). At this point, the antibodies are handled by protein complexes which bind to the surface of the invader (much the same as the process of T cells in viruses). In other words, the body goes through a similar reaction of identifying and then attempting to destroy the invader, including the formation of a membrane attack complex. “MAC can insert into the cell membrane of Gram-negative, but not Gram-positive, bacteria. There, it produces pores that allow the entry of membrane damaging molecules, such as lysozyme, and makes the bacterium susceptible to osmotic lysis” (Immune,

The organs that make up the lymphatic and immune system are the tonsils, spleen, thymus gland, lymph nodes, and lymphatic vessels. White blood cells (leukocytes), red blood cells (erythrocytes), plasma, and platelets (thrombocytes) make up the blood. Lymphocytes are leukocytes (white blood cells) that help the body fight off diseases. Two types of lymphocytes are B cells and T cells. Lymphocytes recognize antigens, or foreign substances/matter, in the body. Lymphocytes are a classification of agranulocytes, or cells (-cytes) without (a-) granules (granul/o) in the cytoplasm. B cells are created from stem cells, which are located in the bone marrow. B cells respond to antigens by becoming plasma cells. These plasma cells then create antibodies. Memory B cells produce a stronger response with the next exposure to the antigen. B cells fight off infection and bacteria while T cells defend against viruses and cancer cells. A hormone created by the thymus gland called thymosin changes lymphocytes into T cells. The thymus gland is active when you are a child and slowly shrinks, as you get older. T cells bind to the antigens on the cells and directly attack them. T cells secrete lymphokines that increase T cell production and directly kill cells with antigens. There are three types of T cells: cytotoxic T cells, helper T cells, and memory T cells.

Peptides of the innate immune system have a broad range of microbicidal activities and can affect Gram positive and Gram negative bacteria as well as mycobacteria, spirochetes, fungi, and some enveloped bacteria. The same can be said of magainin-2 and melittin.(Mark, 601)

When the activity of the GPI-anchored proteins is reduced the mutation is then able to develop into the dominant gene in the creation of red blood cells. The complement system then recognizes the red blood cells as foreign cells causing the complement system to attack the mutation and when this occurs, red blood cells are destroyed faster than the normal 120 day life span, which leads to the deficiency of red blood cells and all the nutrients that they carry. In PNH, the red blood cells are missing two of the complement regulating proteins that are needed for GPI-anchored proteins to attach them to the cell membrane and since the two proteins are missing a lot of the nutrients and are in a deficient amount, it can lead to hemolytic anemia, iron deficiency anemia, aplastic anemia, blood clots, myelodysplasia, acute myelogenous leukemia, and even

This multiplication continues until cell-mediated immune response developed. Once the adaptive cell-mediated immune response developed, migration of neutrophils, lymphocytes and other immune cells to the site of primary infection form a cellular infiltrate which is called granuloma [8]. The process takes approximately 2 years [9-11]. Granuloma is covered by fibrotic components, which becomes calcified where Mtb remains encapsulated inside and protected by the host immune response. The Mtb can survive for years, decades or for lifetime in this protective and non-metabolically active state (latent TB) [12]. During latent state, a dynamic equilibrium between Mtb and host immune response is established and any suitable conditions that weakens cell mediated immunity may lead to break down of granuloma, replication of bacteria and turn to active disease (active

Two of the main functions of galectin-8 are cell adhesion and cell growth. These functions also occur in the protease-resistant form of galectin-8. Galectin-8 is a type of protein that is secreted. When it is secreted, is serves a modulator for cell adhesion [3]. When the protein is stopped, it promotes cell adhesion. This occurs by ligation and gathering of a select group of integrin receptors [3]. Recall that galectin-8 is a sugar binding protein. Therefore, when there is a formation between galectin-8 and integrins, it activates integrin-mediated signaling [3]. When there are large amounts of galectin-8 present, it negative regulates cell adhesion with it forms a complex with integrins. Cell adhesion depends on the interactions between galectin-8

The human immune system plays a major role in every person’s body. It protects the body against foreign particles that could lead to diseases, such as bacteria and viruses. A white blood cell protein, called CD4, play a key role in the human immune system. Without the help of CD4 proteins, bodies would not be able to receive the signal to activate the body’s immune response against foreign contaminants entering the body.

Lectin is a type of ' (WGA) and glycoprotein used for increasing wheat reproduction. It acts as a defense system for the plant, guarding against fungus and insects. As it accumulates in the tissues of the body, the immune system kicks in causing discomfort in the small intestine. Eventually it breaks down, unable to absorb essential nutrients. When this happens, health issues arise. This protein is very difficult for humans to digest because it is created from the very same materials that make vulcanized rubber. It also acts as an ingredient for hair products that advertise strong, flexible, manageable hair. The greatest quantities of (WGA) is found in whole wheat products.

When HL-60 cells are treated with PMA they differentiate into monocytes and when HL-60 cells are treated with DMSO they mainly differentiate into granulocytes. Monocytes and granulocytes are both a part of the immune system, meaning the human body uses them to fight foreign invaders, and have some similarities that help signify commonalities in their functions as white blood cells; however, they also have some differences that highlight their distinct characteristics that allow them to attack unwelcome intruders in their own unique ways. One of the similarities between monocytes and granulocytes is that they both produce matrix metallopeptidase 2, or MMP-2, but one of the differences between these two cell types is that only monocytes produce matrix metallopeptidase 9, or MMP-9. Matrix metalloproteinases, such as MMP-9 and MMP-2, break down proteins in the extracellular matrix allowing cells to move from one place to another. The ability to move is somewhat important for granulocytes, which move a to an intruder and explode to fight off infection, but the ability to move is vitally important for monocytes, which move to areas of infection and digest the pathogens and then move

However, the production of Matrix Metalloproteinase (MMP) is also responsible for the degradation of the extracellular matrix of synovium(Tan et al., 2006).

The P-type lectins, CD-MPR and CI-MPR, are among the most extensively characterized lectins in the secretory pathway (for reviews see [110-112]). Comprising the only two members of this family, MPRs are defined by their unique ability to bind phosphomannosyl residues. The only known function of the CD-MPR is targeting newly synthesized acid hydrolases to the lysosome, whereas the CI-MPR is a multifunctional protein that interacts with several different ligands, including M6P-tagged acid hydrolases as well as the non-M6P-containing proteins insulin-like growth factor 2 (IGF-2) [113, 114], plasminogen [115, 116], and urokinase-type plasminogen activator receptor [117, 118]. Transgenic mice lacking the CD-MPR are viable [119]. Mice lacking

Pathogenic L. monocytogenes go through an intracellular life cycle involving early escape from the phagocytic vacuole, rapid intracytoplasmic multiplication, bacterially induced actin-based motility, and direct spread to neighboring cells, in which they reinitiate the cycle. The bacterium is first phagocytosed by these cells and secretes a pore-forming toxin called listeriolysin, which allows the bacterium to escape from the phagosome. All virulent strains of L. monocytogenes synthesize and secrete listeriolysin. Phospholipase A and B are other virulence factors that facilitate escape of L. monocytogenes from the phagosome. Once out of the phagosome L. monocytogenes is capable of rapid division in the cytoplasm, evading the immune response and moving throughout the cytoplasm from cell to cell. L. monocytogenes is well known for its ability to propel itself like a rocket through the cell cytoplasm. This is the result of the bacterium’s ability to polymerize actin filaments at its tail end. Actin is arranged in subunits to form microfilaments that are capable of directing cell movement. L. monocytogenes accomplishes cell motility through a virulence factor called ActA that takes advantage of normal actin polymerization going on in the cell. The ActA protein shares sequence homology with a protein called WASP that is found in virtually all eukaryotic cells. WASP is responsible for recognizing and