Variation and homology in the mu and gamma heavy chains of human immunoglobulins

The Impact of the Hybridoma Technology on the R&D of Idiotypic Antibodies

The PubMed data set was scanned with the title and abstract term "Idiotype" followed by secondary searches with "Vaccine" and "Clinical trial." The retrieved references were analyzed from the period before and after hybridoma technology (1975). In 1963, Oudin and Kunkel discovered that antibodies against antibodies can be raised to identify determinants unique to an antibody termed idiotype or individual antigenic determinant. Two laboratories reported that anti-idiotypic antibodies can suppress specific antibody responses in mice. In 1974, Jerne proposed a network of idiotypes and anti-idiotypes and the functionality of the idiotype network was confirmed. This prompted the proposal of a symmetrical regulatory immune response. By 1989, the concept and the functional parameters of the immune idiotype network were established in the prehybridoma period. It was not until 1981 that monoclonal anti-idiotypic antibodies were used as tools to study the expression of idiotypic determinants on antibodies and to categorize functional properties in the immune network as network antigens in 1989. Hybridoma-generated monoclonal anti-idiotypic antibodies provided the tools to precisely identify different idiotypic regions on antibodies and test these as targets to induce network cascades. The initial distinction of Ab2s as alpha and beta were expanded to include gamma and delta. The initial concept of Ab2beta being an antigen internal image, used as vaccine, was challenged showing that targeting all idiotopes on B cell receptors can induce specific antibodies. After the discovery of the hybridoma technology a wave of idiotype topic publications occurred, that declined by 2015. In 1985, in this wave of reports on anti-idiotypes, their importance to vaccines dominated. These vaccines targeted in animal models parasite, bacterial, and viral diseases, and cancer. The reported data indicated a therapeutic response in inbred mice. The issue of idiotype matching between mouse haplotypes of vaccine origin and treated mice were raised. In 1995, the human clinical trials in different cancers using anti-Id vaccines were reported. Only one such vaccine received conditional approval in Argentina and Cuba, whereas the other trials failed in phase II and III. The reasons for this failure were subsequently discussed. Although the use of the Milstein and Kohler hybridoma technology and subsequently alternative methods to produce monoclonal animal and human antibodies created a new class of drugs, commonly referred as "Biological," it failed on the promise therapeutic of anti-Id vaccines.

Glycosylation of the overlapping sequons in yeast external invertase: effect of amino acid variation on site selectivity in vivo and in vitro

Yeast invertase contains 14 sequons, all of which are glycosylated to varying degrees except for sequon 5 which is marginally glycosylated, if at all. This sequon overlaps with sequon 4 in a sequence consisting of Asn92-Asn93-Thr94-Ser95(Reddy et al., 1988, J. Biol. Chem., 263, 6978-6985). To determine whether glycosylation at Asn93is sterically hindered by the oligosaccharide on Asn92, the latter amino acid was converted to a glutamine residue by site-directed mutagenesis of the SUC2 gene in a plasmid vector which was expressed in Saccharomyces cerevisiae. A glycopeptide encompassing sequons 3 through 6 was purified from a tryptic digest of the mutagenized invertase and sequenced by Edman degradation, which revealed that Asn93 of sequon 5 contained very little, if any, carbohydrate, despite the elimination of sequon 4. When Ser and Thr were inverted to yield Asn-Asn-Ser-Thr carbohydrate was associated primarily with the second sequon, in agreement with numerous studies indicating that Asn-X-Thr is preferred to Asn-X-Ser as an oligosaccharide acceptor. However, when the invertase overlapping sequons were converted to Asn-Asn-Ser-Ser, both sequons were clearly glycosylated, with the latter sequon predominating. These findings rule out steric hindrance as a factor involved in preventing the glycosylation of sequon 5 in invertase. Comparable results were obtained using an in vitro system with sequon-containing tri- and tetrapeptides acceptors, in addition to larger oligosaccharide acceptors.

Complete amino acid sequence of the Mu heavy chain of a human IgM immunoglobulin

The amino acid sequence of the micro, chain of a human IgM immunoglobulin, including the location of all disulfide bridges and oligosaccharides, has been determined. The homology of the constant regions of immunoglobulin micro, gamma, alpha, and epsilon heavy chains reveals evolutionary relationships and suggests that two genes code for each heavy chain.

Initiation of protein synthesis at an unusual position in an immunoglobulin gene?

The amino acid sequence of urinary beta(2)-microglobulin has been partially determined and found to be related to the constant region of IgG immunoglobulin heavy chain. beta(2)-Microglobulin is present in normal individuals. Its gene may have evolved from an immunoglobulin gene by the use of an unusually located start signal for initiating synthesis of the polypeptide.