Colony morphology variation of Burkholderia pseudomallei is associated with antigenic variation and O-polysaccharide modifications

Chanthiwa Wikraiphat, Natnaree Saiprom, Sarunporn Tandhavanant, Christian Heiss, Parastoo Azadi, Gumphol Wongsuvan, Apichai Tuanyok, Matthew Holden, Mary N Burtnick, Paul J Brett, Sharon J Peacock, Narisara Chantratita

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)
6 Downloads (Pure)

Abstract

Burkholderia pseudomallei is a CDC Tier 1 select agent that causes melioidosis, a severe disease in humans and animals. Persistent infections are common and there is currently no vaccine available. Lipopolysaccharide (LPS) is a potential vaccine candidate. B. pseudomallei expresses three serologically distinct LPS types. The predominant O-polysaccharide (OPS) is an unbranched heteropolymer with repeating d-glucose and 6-deoxy-l-talose residues in which the 6-deoxy-l-talose residues are variably substituted with O-acetyl and O-methyl modifications. We observed that primary clinical B. pseudomallei isolates with mucoid and non-mucoid colony morphologies from the same sample expressed different antigenic types distinguishable using a LPS-specific monoclonal antibody (Mab). Mab reactive (non-mucoid) and non-reactive (mucoid) strains from the same patient exhibited identical LPS banding patterns by silver staining and indistinguishable genotypes. We hypothesized that LPS antigenic variation reflected modification of the OPS moieties. Mutagenesis of three genes involved in LPS synthesis was performed in B. pseudomallei K96243. Loss of Mab reactivity was observed in both wbiA (encoding a 2-O-acetyltransferase) and wbiD (putative methyl transferase) mutants. The structural characteristics of the OPS moieties from isogenic non-mucoid strain 4095a and mucoid strain 4095c were further investigated. Utilizing NMR spectroscopy, we found that B. pseudomallei 4095a and 4095c OPS antigens exhibited substitution patterns that differed from the prototypic OPS structure. Specifically, 4095a lacked 4-O-acetylation while 4095c lacked both 4-O-acetylation and 2-O-methylation. Our studies indicate that B. pseudomallei OPS undergoes antigenic variation and suggest that the 9D5 Mab recognizes a conformational epitope that is influenced by both O-acetyl and O-methyl substitution patterns.

Original languageEnglish
Pages (from-to)2127-2138
JournalInfection and Immunity
Volume83
Issue number5
Early online date16 Mar 2015
DOIs
Publication statusPublished - May 2015

Keywords

  • Melioidosis
  • Burkholderia pseudomallei
  • Lipopolysaccharide
  • O-polysaccharide

Fingerprint

Dive into the research topics of 'Colony morphology variation of Burkholderia pseudomallei is associated with antigenic variation and O-polysaccharide modifications'. Together they form a unique fingerprint.

Cite this