O-mannosylation of the Mycobacterium tuberculosis adhesin Apa is crucial for T cell antigenicity during infection but is expendable for protection.

Autor: Subhadra Nandakumar, Sunil Kannanganat, Karen M Dobos, Megan Lucas, John S Spencer, Sunan Fang, Melissa A McDonald, Jan Pohl, Kristin Birkness, Venkateswarlu Chamcha, Melissa V Ramirez, Bonnie B Plikaytis, James E Posey, Rama Rao Amara, Suraj B Sable
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: PLoS Pathogens, Vol 9, Iss 10, p e1003705 (2013)
Druh dokumentu: article
ISSN: 1553-7366
1553-7374
DOI: 10.1371/journal.ppat.1003705
Popis: Glycosylation is the most abundant post-translational polypeptide chain modification in nature. Although carbohydrate modification of protein antigens from many microbial pathogens constitutes important components of B cell epitopes, the role in T cell immunity is not completely understood. Here, using ELISPOT and polychromatic flow cytometry, we show that O-mannosylation of the adhesin, Apa, of Mycobacterium tuberculosis (Mtb) is crucial for its T cell antigenicity in humans and mice after infection. However, subunit vaccination with both mannosylated and non-mannosylated Apa induced a comparable magnitude and quality of T cell response and imparted similar levels of protection against Mtb challenge in mice. Both forms equally improved waning BCG vaccine-induced protection in elderly mice after subunit boosting. Thus, O-mannosylation of Apa is required for antigenicity but appears to be dispensable for its immunogenicity and protective efficacy in mice. These results have implications for the development of subunit vaccines using post-translationally modified proteins such as glycoproteins against infectious diseases like tuberculosis.
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