Isotype of antibody

Class switching Change in the isotype of antibody produced after a B cell has encountered an antigen. 

Hurwitz, J.L., Coleclough, C., Cebra, J.J. (1980). gene rearrangements in IgM-bearing B cells and in the normal splenic DNA component of hybridomas making different isotypes of antibody. Cell 22,349-359. 

In humans, there are five isotypes of antibodies, IgG, IgA, IgD, IgE, and IgM, which are defined by the structures of their heavy chains and their abilities to form multimers (Figure 10.1) [8], IgG is the most abundant isotype present in serum with average serum concentrations ranging from 0.5 to 9mg/ml depending on the IgG subtype. This is followed by IgA (3mg/ml), IgM (1.5mg/ml), IgE (0.05 mg/ml), and IgD (trace). Each antibody isotype has unique functions. Critical functions of IgG include opsonization, complement activation, antibody-dependent cell-mediated cytotoxicity (ADCC), passive immunity, and regulation of B cells. Both IgM and IgD act as antigen receptors on naive B cells, and soluble, multimeric forms of IgM are involved in complement activation. IgA is involved in mucosal and passive neonatal immunity, while IgE is involved in immediate hypersensitivity [8],... 

IgG, the most prevalent of the antibody classes, comprises approximately 80% of serum antibody. IgG is usually the second isotype of antibody to be produced in an initial humoral immune response. IgG is the only isotype of antibody that can cross the placenta. Therefore, early maternal humoral protection of neonates is primarily due to maternal IgG that crossed the placenta in utero. 

This chapter summarizes our recent efforts to establish two different protein/ enzyme dosing models in mice, using intratracheal and intranasal dosing. Both models have been used to measure antigen (enzyme) specific antibody responses as a function of the dose of antigen administered, the immunization procedure and regimen, and the isotype of antibody produced. 

Hunter, R., M. Olsen and S. Buynitzky, 1991, Adjuvant activity of non-ionic block copolymers. IV. Effect of molecular weight and formulation on titre and isotype of antibody. Vaccine 9 250-256. 

Allison, A. C., and Byars, N. E. (1986). An adjuvant formulation that selectively elicits the formation of antibodies of protective isotypes and of cell-mediated immunity, J. Immunol. Meth.. 95. 157-168. 

Maizels, R.M., Sartono, E., Kurniawan, A, Partono, F., Selkirk, M.E. and Yazdanbash, M. (1995) T-cell activation and the balance of antibody isotypes in human lymphatic filariasis. Parasitology Today 11, 50-56. 

For double immunolabeling with primary antibodies from the same host species, it is not necessary to resort to labeling with monovalent Fab fragments when primary antibodies from the same host species are different isotypes (subclasses) of IgG, for instance such as mouse IgGl and mouse IgG3. In these cases, isotype-specific antibodies may be used to distinguish between the two primary antibodies... 

Secondary antibodies Incubate sections for 60 min at room temperature with a mixture of secondary fluorophore-conjugated antibodies raised against the corresponding IgG isotypes of primary antibodies. Wash sections in PBS for 2x3 min. 

Primary and secondary antibodies Primary antibodies are raised against the antigen under study, whereas secondary antibodies are raised against the corresponding IgG species or isotype of the primary antibody. 

Other substances that exhibit specific binding may be used to separate the free and the bound fractions when attached to a solid phase the ability of staphylococcal protein A to bind to the FC fragment of certain isotypes of IgG can be utilized the strong binding of the vitamin biotin to tetravalent avidin may also be employed. Biotin may be readily incorporated into antibody molecules and these molecules may be subsequently captured by an avidin solid phase. Alternatively avidin may be used to provide a link between a biotinylated antibody and a biotinylated solid phase. 

Peripheral T-Cell Tolerance to Allergens Is Associated with Regulation of Antibody Isotypes and Suppression of Effector Cells... 

As is documented in Table 2, the induction of anti-carbohydrate immune responses has been successfully demonstrated for many peptides. However, certain challenges remain. Often, the induced antibody titer (concentration) directed against the carbohydrate is rather weak, especially in comparison to the anti-peptide response the majority of antibodies recognize the peptide presumably in a nonmimetic conformation. Several recent studies have investigated these immime responses in more detail, with an extensive analysis of antibody isotypes and adjuvant effects [70,75], the effect of different protein carriers [194], the use of DNA vaccines [48,195], and the demonstration of protection by passive immunization [72,75,194]. In several cases, the anti-carbohydrate immune response has also been shown to be protective against infection in mice [30,72,75,78], and these cases are probably the most promising for the development of vaccines. 

Plasma clearance (Cl), blood-brain barrier permeability surface area product (PS) and accumulation as % injected dose detected in brain tissue (%ID tissue) at 1 h after administration. Results show free [ H]-daunomycin (Daunomycin), [ H]-daunomycin encapsulated in conventional liposomes (Liposomes), sterically stabilized liposomes (PEG-liposomes), immunoliposomes (29 0X26, where 29 designates the number of 0X26 mAb conjugated per liposome) and control immunoliposomes where the 0X26 mAb was replaced by a non-specific isotype control antibody (IgG2a). Values are means SEM of n = 3 experiments. 

Aroxmd the same time, Beckman Instruments (now Beckman Coulter) had begun an array-based product development program focused on the use of modified plastics. Silzel and coworkers (1998) and Matson et al. (2001) of Beckman Coulter were among the first to pursue printing of antibodies onto a plastic surface in a microarray format. Silzel et al. immobilized biotinylated monoclonal antibodies onto an avidin-coated polystyrene surface and performed micro-ELISA-based isotyping of IgG species. Matson et al. 

Antibody isotypes can change upon B-cell activation. Upon maturity, both IgM and IgD become expressed as membrane-bound forms on the B cell surface. Activation results in the production of antibody in secreted forms. Isotype switching takes place with some daughter cells to pro-... 

Serum from immunized animals contains a large number of antibodies of varying isotype, affinity, and specificity, called polyclonal because they are products of different cell types. Different clones respond to different antigenic sites on the hapten to create a mixture of antibodies. Some of these antibodies will... 

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