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Idiotypic determinants

Idiotypic network. Idiotypic determinants (idiotypes) are unique antigenic epitopes characteristic of the antigen receptors on the surface of T and B cells. They are associated with the variable regions of these receptors. Antibodies produced by B cells as the result of antigenic stimulation can themselves stimulate the production of auto-anti-idiotypic antibodies which have the ability to combine with the B-cell receptor (Ig) and thus can dampen down the immune response. Idiotypes may likewise stimulate the production of T cells specific for idiotypic determinants. Jerne (1974) postulated his... [Pg.296]

Idiotypic specificity—Antibodies and myeloma globulins of a given specificity show differences in antigenic specificity ascribable to differences in sequence in the variable regions of their light and heavy chains. Some of these idiotypic determinants are inhibitable by the antigenic determinant or ligand for which the antibody or myeloma protein is specific, whereas others are not. Those idiotypic determinants which are inhibitable are hypothesized to in-... [Pg.5]

A large body of data has been amassed indicating that the structure of antibodies elicited by a T cell dependent form of an antigenic determinant varies substantially in comparison to a T cell independent form of the same determinant. The variation in predominant isotypic class of antibody elicited by T dependent as well as independent antigens is well documented (reviewed in [146]). Expression of idiotypic determinants by the elicited antibody population has been observed to differ substantially in responses to T cell dependent and independent forms of the same haptenic determinant [147]. The participation of T cells during a humoral immune response clearly influences the structure of the antibodies elicited. [Pg.197]

The full expression of an idiotypic determinant is generally dependent on the presence of both the heavy and light chains of an immunoglobulin (e.g., see Carson and Weigert, 1973 Laskin et al., 1977). There are occasional examples, however, where a single chain can be shown to bear a given determinant. [Pg.112]

In addition to their intrinsic interest, idiotypic determinants have proven, and are continuing to prove, of great value in analyzing genetic aspects of the control of antibody synthesis, a topic that is beyond the scope of this chapter. [Pg.112]

It would be of extreme interest to determine whether any interspecies idiotypic cross-reactions could be observed. Could there be, for example, a cross-reaction between idiotypic determinants on an antibody of given specificity (say, antidinitrophenol) produced in a second species. To the authors knowledge, no reports of such cross-reactivity have yet appeared. However, the basic unity observed in the construction of the antibody-combining-site structure, at least among mammalian species, would suggest that such interspecies cross-reactivity is a very real theoretical possibility. [Pg.113]

Amyloid proteins related to immunoglobulin possess individually specific (idiotypic) antigenic determinants i.e., such amyloid proteins from different individuals possess unique primary structures. Idiotypic determinants characteristic of a given amyloid protein can sometimes be detected in the serum of the same individual. In addition, however, amyloid proteins of a given type (it or X) frequently have shared antigenic determinants (120,124,126). Antiserum directed to an amyloid protein will, in general, cross-react weakly with normal L chains of the same type. It seems likely that these cross-reactions are attributable, in the case of the smaller amyloid proteins, to shared V region sequences. [Pg.191]

A number of different mouse myeloma proteins [IgA(/f)] have the capacity to bind phosphorylcholine (77,92-94). There is evidence that some of these proteins, which arose independently in different mice, may be very similar or identical in structure. This evidence includes idiotypic specificity and partial sequence analyses (Chapter 11). These proteins also react with pneumococcal type C polysaccharide, which contains haptenic determinants resembling phosphorylcholine. There exist other mouse myeloma proteins which are also reactive with phosphorylcholine but which differ in structure, as shown by differences in their idiotypic determinants, affinities for various haptens related to phosphorylcholine, and partial amino acid sequences. Leon and Young (92) recognized three classes of myeloma proteins with antiphosphorylcholine activity. Class 1 is characterized by a fairly high affinity for choline as well as phosphorylcholine the other two classes do not combine well with choline. Classes 2 and 3 are distinguished by differences in affinity for phosphonocholine. Leon and Young identified four proteins in class 3 all of these had previously been shown by Potter and Liebermann (77)... [Pg.434]

A number of myeloma proteins induced in BALB/c mice have been found to bind a( 1 3)dextran. They have been studied extensively by Cohn, Weigert, and their associates (79,100). Many of these proteins share idiotypic determinants, and when this is the case they have X... [Pg.435]

A contribution of the constant region of a polypeptide chain to an idiotypic determinant is conceivable, but idiotypic differences among proteins must reflect differences in the variable regions. Isotypic and allotypic antigenic determinants similarly reflect particular amino acid sequences, which in many instances have been defined. [Pg.445]


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See also in sourсe #XX -- [ Pg.110 , Pg.111 , Pg.112 ]




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