[ODP13] 3. Physiology / Structural biology -d. Cell surface structure, membrane structures and cytoskeleton

[ODP-063] Glycopeptidolipid in nontuberculous bacteria relates the colony morphology and host responses

Nagatoshi Fujiwara¹, Takashi Naka¹, Minoru Ayata², Yuji Miyamoto³, Saburo Yamamoto⁴, Shinji Maeda⁵ (¹Dept. Food and Nutrition, Fac. Contemporary Human Life Science, Tezukayama Univ., ²Dept. Virology, Osaka City Univ. Grad. Sch. Med., ³Leprosy Research Center, National Instit. Infect. Disea., ⁴Japan BCG Laboratory, ⁵Fac. Pharmacy, Hokkaido Univ. of Science)

MAC (Mycobacterium avium-intracellulare complex) is one of the major nontuberculous bacteria, and is classified into 28 serotypes by the serotype-specific glycopeptidolipid (GPL). We have reported the presence of core GPL in M. smegmatis and M. abscessus, and found the deletion of GPL in some strains. The colony morphology of the GPL-deleted strains changed rough-type instead of smooth-type, and implies to affect their virulence and pathogenicity.In this study, we showed the features of a clinical isolate, M. intracellulare Ku11 which produced a novel GPL. Its oligosaccharide was defined as α-Rha-(1→3)-2-O-Me-α-Rha-(1→3)-α-Rha-(1→3)-α-Rha-(1→3)-α-Rha-(1→2)-6-d-α-Tal. We analyzed the gene cluster involved in the GPL biosynthesis, and found the similarity of the deduced amino acid sequences in the eight open reading frames (orfs). We introduced the orf1, 6, 8 into M. intracelullare NF113 which produces serotype-1 GPL. We also deleted the orf8 in the Ku11 genome by CRISPR-Cas9 system. The orf1, 6, 8 were functionally responsible for the elongation of oligosaccharide, as a glycosyltransferase. Futhermore, we found that the intact Ku11-GPL was acetylated in some positions of oligosaccharide, and was recognized via TLR2. This result indicates that acetylation of GPL plays critical roles in host recognition. We discuss the structural and functional diversity of GPLs.