engleski

A sweet glimpse of rat immunoglobulin G glycosylation: towards comprehensive rodent animal model glyco(proteo)mics

Lab rats have traditionally been favoured as experimental animals because, compared to mice now holding primacy as a vertebrate disease model, their physiology and metabolism resembles more closely that of the humans. Since no -omics studies can be considered complete anymore without introducing glycomics dataset, mouse IgG N-glycosylation is already well explored. The fact that rat serum glycoprofiling has been conducted only recently calls for a thorough examination of normal and pathological rat IgG N-glycosylation patterns, encompassing both glycomic and glycoproteomic approaches. An array of protocols for efficient rat IgG isolation using protein L affinity chromatography, PNGase F deglycosylation, fluorescent labelling of free glycans, purification and PGC enrichment as well as tryptic glycopeptides preparation combined with HILIC- or RP-SPE for subclass-specific IgG analysis was developed. Suitable UPLC-FLR and nano-LC-ESI-QqTOF methods were also established. Specific-pathogen-free Wistar rat serum was used as a test sample and preliminary results indicate an excellent recovery of IgG. Rat IgG glycome is dominated by mono- and digalactosylated glycans bearing core fucose followed by bisected structures. Interestingly, sialylated glycans carry almost exclusively N-glycolylneuraminic acid although N-acetylneuraminic acid is also expressed in rat. These findings suggest that glycosylation patterns share some similarities with those of mice and humans, yet full elucidation of how glycans alter rat IgG effector functions remains to be done. A high-throughput rat IgG glycoproteomic analysis workflow suitable for IgG2a, IgG2b and IgG2c analysis in larger cohorts has recently been introduced in our lab. Thorough understanding of rat antibodies glycosylation will contribute to immunobiology of this popular animal model and hopefully open new fields of research such as nutriglycomics or pharmacoglycomics.

Immunoglobulin G ; Rat ; Glycosylation

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