mucosal immune response

Mucosal component :
Local immune component are recently being talked by immunologist as an active local immune system it consist of both B- and T- Cells epithelial cell producing secretory piece they can fix up both humoral and cellular immune response in site , the mucosa – associated lymphoid tissue or (MALT) the main mucosa- associated lymphoid tissue are the gastrointestinal tract ( including oral mucosa and salivery gland , the genitourinary tract , the respiratory tract and the secretion of the mammary glands this local immune stimulated through mucosa- associated lymphoid tissue which is organized into discrete areas in the gut known as Peyer patches just below the epithelial cells in the lamina propria Antigen travels through specialized epithelium(M Cells) to the subepithelial lymphoid tissue. The main antibody produced at these sites is secretory IgA , dimeric immunoglobulin which aquires it secretory component during transport across the epithelium.

mmunity of oral cavity : the oral cavity environment is controlled primary by saliva mucosal surface saliva contain several non-specific host factores (mucins,lactoferrin,lysozyme, peroxidase, Histatins, cystains, salivery glycoprotein)
It is well established that S.IgA is predominant immunoglobulin in whole saliva it is considered to be the main specific defense mechanism in oral surface by limiting
microbial adherence to epithelial & tooth surface by neutralizing toxin& host factors anther part of oral cavity is the gingival cervical fluid : Blood component ,including leucocytes are able to reach the oral cavity via the flow of fluid through the junctional epithelium of the gingival cervicular fluid increases greatly with the inflammation accompany periodontal disease in addition to immunoglobulin ,complement system have been detected , other component such as lysozyme , protease and collegians & cervical fluid comprises Neutrophile with some number of macrophage and B- and T-Cell these cells migrate continuosly from Blood through the junctional epithelium into the gingival cervic over 80% of macrophage of Neutrophiles in gingival cervic are functional and can phagocytose microorganism .
It is clear therefore , that the tooth surface by both local salivery mechanism and systemiuc immunity.


Atigen and Antibody Reaction
Antigen-Antibody reactions are useful in Laboratory diagnosis of various diseases and in the identification of infectious agents in epidemiological
survey. Antigen - antibody reactions in vitro are called serological reactions.
The following are the important tests based on
antigen -Antibody reactions
• Agglutination
• Precipitation
• Redioimmunoassay
• ELISA
• Immune fluorescence
• Neutralization
• Haemagglutination
• Antiglobulin test ( comb’s test )
• Complement fixation test. and other tests using complement system

Precipitation:
The antigen -Anti body complex is not. found firmly together and may dissociate spontaneously unless PH, salt concentration and temperature are properly the antigen — antibody complex forms insoluble Precipitate.

The use of precipitation reaction in:
1- identification of bacteria, example detection of group Specific polysaccharides substance in streptococci in Lancefield group.
2- Identification of antigen component of bacteria in infected animals tissue. Example bai1lus anthracis (Ascoli test)
3- Standardization of toxin and anti- toxins.
4- Demonstration of antibody in serum, as kahn’s test for the diagnosis of syphilis.
Mechanism of precipitation is lattic hypothesis explains it.
Lattic hypothesis: is multivalent antigens combine with bivalent antibody in varying proportions , depending antigen antibody ratio in reaction mixture Precipitation results.
When large lattice is formed consisting of alternating antigen and antibody molecules in the zone of equivalence.
precipitation is maximum when optimal proportions of
antibody combine precipitation can be produced in solutions or in semisolid (agar gel) medium, precipitation in solution can be shown by adding these two on a slide and mixing well or in small narrow tubes.





Enzyme –linked immunosorbem assay (ELIZA):
It is simplest form of this technique is summarize in diagram ,it can be used to detect antibodies in serum or other body fluids by binding them to an antigen coated to a solied phas ( a well in polystyrene multi-well plate) the bond antibody can then be detected by adding a tagged second antibody which recognize the first as antigen . this second antibody covalently labeled with an enzyme the first as antigen . the complex of antigen , first antibody and the second antibody-Enzyme conjugate is detected by adding achromogenk substrate for the enzyme, the intensity of colour produced which is proportional to the amount of antibody bound by microplate spectrophotometer.
(ELIZA) is one of diagnostic procedures for vast microbial pathogen particularly in virus serology. Detection of antigen is less frequently used but it has a role in detection of microorganisms or toxin of normally sterile sites such as antigen of meningitis – causing in cerebrospinal fluid
anther technique immunobiotcing (westering blotting) both technique involve the ultimate detection of antibody-antigen complex.
From (ELIZA) The different here the product must be insoluble as well as coloured by using autoradiografy.