What does it mean to Opsonize?
Opsonization is an immune process which uses opsonins to tag foreign pathogens for elimination by phagocytes. Without an opsonin, such as an antibody, the negatively-charged cell walls of the pathogen and phagocyte repel each other.
What causes opsonization?
Opsonization occurs through the binding of an opsonin to an epitope of the pathogen or dead cells. Immune cells and pathogens all have negatively charged cell membranes. This causes the phagocyte and pathogen to be repelled away from each other.
Which antibodies do opsonization?
Opsonization of bacteria takes place when immunoglobulin G (IgG) molecules bind to specific epitopes on bacterial surface antigens through the antigen-binding site of the IgG molecule.
What can act as an opsonin?
First, specific antibody alone may act as an opsonin. Specific antibody may also act as an opsonin in concert with complement, by activating C3 via the classic pathway of C1, C4, and C2. Finally, there is a nonspecific mechanism of opsonization present in nonimmune animals called the heat-labile opsonin system.
What is example of opsonization?
Examples of opsonins are antibody molecules such as the IgM that are capable of activating the complement system to increase the susceptibility of antigens to phagocytosis. Apart from phagocytosis, opsonization can also promote antibody-dependent cell-mediated cytotoxicity.
What is opsonization and why is it important?
Opsonization is the important process in host defense by which particles or complexes are made readily ingestible for uptake by phagocytic cells. Specific serum proteins, known as opsonins, coat particles and cause the particles to bind avidly to phagocytes and trigger ingestion.
What is an example of opsonization?
Why is opsonization important?
Which is strongest opsonin?
C3b is by far the most effective opsonin that initiates phagocytosis as it can be recognized by phagocyte receptors.
What are some examples of opsonins?
Examples of opsonins include IgG antibody – part of the immune response – and the C3b molecule of the complement system. Each has receptors for both foreign particle and host phagocyte.
What is an effect of opsonization?
Abstract. Entry of opsonized pathogens into phagocytes may benefit or, paradoxically, harm the host. Opsonization may trigger antimicrobial mechanisms such as reactive oxygen or nitric oxide (NO) production but may also provide a safe haven for intracellular replication.
Where are opsonins found?
Therefore, Some opsonins (including some complement proteins) have evolved to bind Pathogen-associated molecular patterns, molecules only found on the surface of pathogens, enabling phagocytosis of these pathogens, and thus innate immunity.
What are the major opsonins?
Opsonins. Specific IgG, complement, and mannose-binding lectin are the major opsonic factors promoting recognition and ingestion of most microorganisms by neutrophils, although mannose-binding lectin figures predominantly in recognition of fungi rather than bacteria.