Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2012 Mar 13:2:19.
doi: 10.3389/fcimb.2012.00019. eCollection 2012.

Nontypeable Haemophilus influenzae: the role of N-acetyl-5-neuraminic acid in biology

Michael A Apicella  1
Affiliations
Review

Nontypeable Haemophilus influenzae: the role of N-acetyl-5-neuraminic acid in biology

Michael A Apicella. Front Cell Infect Microbiol. .

Abstract

Nontypeable Haemophilus influenzae (NTHi) is an exclusive human pathogen, which has evolved a number of unique mechanisms to survive within the human environment. An important part of this is the ability of the organism to take up and incorporate sialic acid into its surface structures. This protects the organism against host adaptive and innate immune factor as well as serving as a mechanism for sustaining itself within biofilms. Recent evidence suggests that this also may be the source of the evolution of human antibodies to non-human sialic acid structures, which can lead to inflammation in the host. In very rare instances, evolution of antibodies to sialylated lipooligosaccharide (LOS) mimics of human antigens can result in autoimmune disease.

Keywords: Neu5Ac; nontypeable Haemophilus influenzae; sialic acid; sialyltransferases.

PubMed Disclaimer

Figures

Figure 1
Figure 1
A diagrammatic representation of the catabolic (■), uptake genes (□), and regulatory gene () of the two Sia operons in the H. influenzae genome are diagrammed in Figure 1. The intergenic region between the catabolic and uptake operons contains the binding sites for SiaR (solid Line) and Crp (dotted rectangle).
Figure 2
Figure 2
A composite model of Neu5Ac uptake, incorporation into LOS and catabolism into the Krebs cycle is shown. The different steps in the process is described in text.
Figure 3
Figure 3
A diagram showing the transmembrane loops of SiaT based on a hydrophobicity plot. The regions corresponding to DctQ and DctM are shown. Model based on prediction program at http://proteinformatics.charite.de/rhythm/index.php?site=helix.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Aspinall G. O., McDonald A. G., Raju T. S., Pang H., Kurjanczyk L. A., Penner J. L., Moran A. P. (1993). Chemical structure of the core region of Campylobacter jejuni serotype O:2 lipopolysaccharide. Eur. J. Biochem. 213, 1029–1037 - PubMed
    1. Bozue J. A., Tullius M. V., Wang J., Gibson B. W., Munson R. S. Jr. (1999). Haemophilus ducreyi produces a novel sialyltransferase. Identification of the sialyltransferase gene and construction of mutants deficient in the production of the sialic acid-containing glycoform of the lipooligosaccharide. J. Biol. Chem. 274, 4106–4114 - PubMed
    1. Brinkman-Van der Linden E. C., Sjoberg E. R., Juneja L. R., Crocker P. R., Varki N., Varki A. (2000). Loss of N-glycolylneuraminic acid in human evolution. Implications for sialic acid recognition by siglecs. J. Biol. Chem. 275, 8633–8640 10.1074/jbc.275.12.8633 - DOI - PubMed
    1. Colli W. (1993). Trans-sialidase: a unique enzyme activity discovered in the protozoan Trypanosoma cruzi. FASEB J. 7, 1257–1264 - PubMed
    1. Cross G. A., Takle G. B. (1993). The surface trans-sialidase family of Trypanosoma cruzi. Annu. Rev. Microbiol. 47, 385–411 10.1146/annurev.mi.47.100193.002125 - DOI - PubMed

MeSH terms