The structural diversity of lipopolysaccharides expressed by genetically defined clinical isolates of nontypeable Haemophilus influenzae

Nontypeable Haemophilus influenzae (NTHi) is an important cause of otitis media and respiratory tract infections. Its lipopolysaccharide (LPS) molecule, an outer membrane component, is a major virulence factor of NTHi. The LPS molecule may also be an efficient target for antibodies which might be protective against NTHi disease.

The present thesis describes the structural analyses of the LPS from a number of NTHi clinical isolates. These isolates have been selected to be representative of the genetic diversity in the natural population of NTHi. The studies revealed extended inter- and intrastrain variability in LPS expression but also the presence of a conserved structural element. Several novel structural features were found, including epitopes not previously observed in Haemophilus influenzae LPS.

The studies were performed using nuclear magnetic resonance spectroscopy, electrospray ionization mass spectrometry and different chemical degradations of the LPS as the principal methods.

List of scientific papers

I. Mansson M, Bauer SH, Hood DW, Richards JC, Moxon ER, Schweda EK (2001). A new structural type for Haemophilus influenzae lipopolysaccharide. Structural analysis of the lipopolysaccharide from nontypeable Haemophilus influenzae strain 486. Eur J Biochem. 268(7): 2148-59.
https://pubmed.ncbi.nlm.nih.gov/11277939

II. Mansson M, Hood DW, Li J, Richards JC, Moxon ER, Schweda EK (2002). Structural analysis of the lipopolysaccharide from nontypeable Haemophilus influenzae strain 1003. Eur J Biochem. 269(3): 808-18.
https://pubmed.ncbi.nlm.nih.gov/11846782

III. Mansson M, Hood DW, Moxon ER, Schweda EK (2003). Structural diversity in lipopolysaccharide expression in nontypeable Haemophilus influenzae. Identification of L-glycerol-D-manno-heptose in the outer-core region in three clinical isolates. Eur J Biochem. 270(4): 610-24.
https://pubmed.ncbi.nlm.nih.gov/12581201

IV. Mansson M, Hood DW, Moxon ER, Schweda EK (2003). Structural characterization of a novel branching pattern in the lipopolysaccharide from nontypeable Haemophilus influenzae. Eur J Biochem. 270(14): 2979-91.
https://pubmed.ncbi.nlm.nih.gov/12846831