Coming of age: carbohydrates and immunity

Abstract

Adaptive immune responses have long been considered the "territory" of antigenic proteins, whereas carbohydrates are characterized as T-cell-independent antigens that are not typically recognized by the complete adaptive machinery. The current modus operandi when searching for dominant epitopes is the use of synthetic peptides designed from the primary structure of interesting target proteins; however, there is growing evidence that sugars can also play a critical role in immune recognition. Findings reported in this issue of the European Journal of Immunology begin to shed light on the differences in protein glycosylation that can occur in association with disorders like rheumatoid arthritis and the effect these changes have on collagen recognition by the immune system. Other recent studies have shown that immunodominant glycopeptide "remnant" epitopes as well as glycosylation changes on self-proteins can generate autoimmunity. Finally, some types of carbohydrates are now known to be processed and presented to T cells by class II MHC. Taken together, these advances illustrate a clear importance for carbohydrate recognition in foreign and self antigens by the adaptive immune system. With the common presence of carbohydrate molecules on eukaryotic, prokaryotic, and viral surfaces, the impact of carbohydrates on adaptive immunity is now indisputable.

Presence of a neo-epitope and absence of amyloid beta and tau protein in degenerative hippocampal granules of aged mice

“…Scale bar 50 μm described in malignant tumour cells (Vollmers and Brändelin 2006). In this case, the epitopes are posttranscriptional modifications of carbohydrate residues on cell surface glycolipids and glycoproteins (Cobb and Kasper 2005). These carbohydrate antigens are prominent targets of immune surveillance and natural IgM antibodies (Brändlein et al 2003;Vollmers and Brändelin 2006).…”

Glycodendrimers: versatile tools for nanotechnology

“…Paradoxically, the major successful developments achieved with carbohydrate-based vaccines stem from the fact that, when properly conjugated to protein carriers, bacterial capsular polysaccharides (CPS) became capable of acquiring the requisite immunochemical ability. The four known carbohydrate antigen uptake mechanisms by antigen presenting cells (APCs) are well documented (Cobb, Kasper, 2005;Icart et al, 2008). The key to successful vaccines resulted from the fact that the common protein carriers contained at least one ~15-amino acids sequence (T cell epitopes) known to bind strongly to Major Histocompatibility Complex (MHC).…”

The pivotal nature of sugars in normal physiology and disease

“…Most aspects of the immune response, both innate and notably adaptive immunity, [17,22,25,78] are either directly or indirectly governed/influenced by glycan moieties. These include cellular aspects such as Haemopoiesis e.g.…”

“…Each glycoform is effectively a distinct molecular species, conveying different physical and biochemical properties, and thus affects vital biological processes such as the bioactivity (e.g. folding, immunogenicity and localization) of glycoconjugates, as well as the synthesis, clearance and degradation of these molecules [11,[19][20][21][22][23][24].…”