Biomaterial Database

[Secretory IgA and the antibacterial defenses of the respiratory tract (author's transl)]. 1977

F B Michel, and J Bousquet, and L Dussourd d'Hinterland

The secretory IgA (IgA S) in bronchial mucus is produced by cells which are derived, at least in part, from the BALT (Bronchus Associated Lymphoid Tissue). The physico-chemical characteristics of IgA S (the amino-acid structure of the alpha chain, the secretory component and the J chain) explain three properties of this antibody which enable it to play its part as the first line of defense on the surface of the mucus, namely its resistance to proteolysis, its adherence and its ability to penetrate mucus. The role of IgA S in the antibacterial defense of the respiratory tract has been in doubt for some time because it does not follow the usual processes of antibacterial action, having neither opsonising nor lytic activity. It is thought at present that IgA S exerts its action in an individual way, more directly and peculiar to the secretory immune-apparatus. It acts by 1) causing agglutination of bacteria and by inhibiting their adsorption on the mucous membranes, 2) inhibiting bacterial reproduction and 3) by inactivating bacterial toxins. The combination of these three processes produces a surface defense system which inhibits bacterial penetration of the mucus. Despite the uncertainties which still exist, it is essential that the fundamental immunological data should be included in the complex picture of the mechanisms of defense of the respiratory tract.

UI	MeSH Term	Description	Entries
D007070	Immunoglobulin A	Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory IgA (IMMUNOGLOBULIN A, SECRETORY) is the main immunoglobulin in secretions.	IgA,IgA Antibody,IgA1,IgA2,Antibody, IgA
D007071	Immunoglobulin A, Secretory	The principle immunoglobulin in exocrine secretions such as milk, respiratory and intestinal mucin, saliva and tears. The complete molecule (around 400 kD) is composed of two four-chain units of IMMUNOGLOBULIN A, one SECRETORY COMPONENT and one J chain (IMMUNOGLOBULIN J-CHAINS).	Colostral IgA,IgA, Exocrine,IgA, Secretory,SIgA,Secretory IgA,Secretory Immunoglobulin A,Exocrine IgA,IgA, Colostral
D007128	Immunoglobulin Fragments	Partial immunoglobulin molecules resulting from selective cleavage by proteolytic enzymes or generated through PROTEIN ENGINEERING techniques.	Antibody Fragment,Antibody Fragments,Ig Fragment,Ig Fragments,Immunoglobulin Fragment,Fragment, Antibody,Fragment, Ig,Fragment, Immunoglobulin,Fragments, Antibody,Fragments, Ig,Fragments, Immunoglobulin
D007144	Immunoglobulin J-Chains	A 15 kDa "joining" peptide that forms one of the linkages between monomers of IMMUNOGLOBULIN A or IMMUNOGLOBULIN M in the formation of polymeric immunoglobulins. There is one J chain per one IgA dimer or one IgM pentamer. It is also involved in binding the polymeric immunoglobulins to POLYMERIC IMMUNOGLOBULIN RECEPTOR which is necessary for their transcytosis to the lumen. It is distinguished from the IMMUNOGLOBULIN JOINING REGION which is part of the IMMUNOGLOBULIN VARIABLE REGION of the immunoglobulin light and heavy chains.	Ig J Chains,J-Chains, Immunoglobulin,Ig J-Peptide,Immunoglobulin J Polypeptide,Immunoglobulin J-Peptide,Chains, Ig J,Ig J Peptide,Immunoglobulin J Chains,Immunoglobulin J Peptide,J Chains, Ig,J Chains, Immunoglobulin,J Polypeptide, Immunoglobulin,J-Peptide, Ig,J-Peptide, Immunoglobulin,Polypeptide, Immunoglobulin J
D007156	Immunologic Memory	The altered state of immunologic responsiveness resulting from initial contact with antigen, which enables the individual to produce antibodies more rapidly and in greater quantity in response to secondary antigenic stimulus.	Immune Memory,Immunological Memory,Memory, Immunologic,Immune Memories,Immunologic Memories,Immunological Memories,Memory, Immune,Memory, Immunological
D009092	Mucous Membrane	An EPITHELIUM with MUCUS-secreting cells, such as GOBLET CELLS. It forms the lining of many body cavities, such as the DIGESTIVE TRACT, the RESPIRATORY TRACT, and the reproductive tract. Mucosa, rich in blood and lymph vessels, comprises an inner epithelium, a middle layer (lamina propria) of loose CONNECTIVE TISSUE, and an outer layer (muscularis mucosae) of SMOOTH MUSCLE CELLS that separates the mucosa from submucosa.	Lamina Propria,Mucosa,Mucosal Tissue,Muscularis Mucosae,Mucous Membranes,Membrane, Mucous,Membranes, Mucous,Mucosae, Muscularis,Mucosal Tissues,Propria, Lamina,Tissue, Mucosal,Tissues, Mucosal
D009093	Mucus	The viscous secretion of mucous membranes. It contains mucin, white blood cells, water, inorganic salts, and exfoliated cells.
D011108	Polymers	Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).	Polymer
D012137	Respiratory System	The tubular and cavernous organs and structures, by means of which pulmonary ventilation and gas exchange between ambient air and the blood are brought about.	Respiratory Tract,Respiratory Systems,Respiratory Tracts,System, Respiratory,Tract, Respiratory
D012141	Respiratory Tract Infections	Invasion of the host RESPIRATORY SYSTEM by microorganisms, usually leading to pathological processes or diseases.	Respiratory System Infections,Upper Respiratory Tract Infection,Upper Respiratory Tract Infections,Infections, Respiratory,Infections, Respiratory Tract,Infections, Upper Respiratory,Infections, Upper Respiratory Tract,Respiratory Infections,Upper Respiratory Infections,Infection, Respiratory System,Infection, Respiratory Tract,Respiratory Infection, Upper,Respiratory System Infection,Respiratory Tract Infection