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Collagen-like proteins in horse pathogenic Streptococcus equi

Karlström, Åsa (2005). Collagen-like proteins in horse pathogenic Streptococcus equi. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2005:99
ISBN 91-576-6998-8
[Doctoral thesis]

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Streptococcus equi subspecies equi is the causative agent of strangles, a respiratory disease that affects horses worldwide. Like other pathogenic bacteria, S. equi subspecies equi expresses a number of extracellular proteins important for the interaction with the host and thus for the pathogenesis. In this thesis, one aim was to identify and characterise novel extracellular proteins in this subspecies. Signal phage display was used to screen the genome of S. equi subsp. equi strain 1866 for signal sequences thereby identifying extracellular proteins. A novel collagen-like protein, SclC, was found and further characterised. The SclC protein, similar to Scl proteins in S. pyogenes, has an N-terminal signal sequence, a unique region, a collagen-like region and a wall-spanning region ending with an LPXTG-motif preceding the membrane-bound region in the C-terminal end. Using bioinformatic tools, the collagen-like protein was found to be a member of a family consisting of seven collagen-like proteins, called SclC-SclI, in subspecies equi. In contrast to mammalian collagen, all these proteins have collagen-like regions that consist of KGD/KGE triplets, which are suggested to be of importance for the structure of the proteins. When sera from horses previously infected with subsp. equi and sera from healthy horses were analysed, antibodies against all seven proteins were detected. Furthermore, antibodies against SclC recognised all members of the family of collagen-like proteins. In an immunisation study in a strangles model in mice, immunisation with SclC resulted in protection against infection by S. equi subsp. equi. The biological role of SclC was further investigated in a collagen lattice gel contraction study to investigate whether mammalian integrins would recognise SclC, which turned out not to be the case. The biological role of the collagen-like proteins identified here is not fully comprehended. However, since the vaccination studies in mice resulted in protection against infection, these proteins have an interesting potential for further vaccine trials in horses.

Authors/Creators:Karlström, Åsa
Title:Collagen-like proteins in horse pathogenic Streptococcus equi
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :November 2005
Number of Pages:39
ALLI. Karlström, Å., Jacobsson, K., Flock, M., Flock, J.-I. and Guss, B. 2004. Identification of a novel collagen-like protein, SclC, in Streptococcus equi using signal sequence phage display. Veterinary Microbiology 104 (179-188). II. Karlström, Å., Jacobsson, K. and Guss, B. SclC is a member of a family of collagen-like proteins in Streptococcus equi subspecies equi that are recognised by antibodies against SclC. (submitted) III. Flock, M., Karlström, Å., Lannergård, J., Guss, B. and Flock, J.-I. Protective effect of vaccination with recombinant proteins from Streptococcus equi subspecies equi in a strangles model in the mouse. (manuscript) IV. Lidén, Å., Karlström, Å., Lannergård, J., Persson, L., Guss, B., Rubin, K. and Rydén, C. An extracellular protein from Streptococcus equi modulates cell mediated collagen lattice contraction. (manuscript)
Place of Publication:Uppsala
ISBN for printed version:91-576-6998-8
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:L Animal production > L73 Animal diseases
Subjects:Not in use, please see Agris categories
Agrovoc terms:horses, streptococcus equi, bacterioses, proteins, pathogens, identification
Keywords:Streptococcus equi, strangles, collagen-like proteins, Scl, extracellular proteins, pathogenic bacteria, phage display, integrins, vaccination
Permanent URL:
ID Code:960
Department:(NL, NJ) > Dept. of Microbiology (until 161231)
Deposited By: Åsa Karlström
Deposited On:01 Nov 2005 00:00
Metadata Last Modified:02 Dec 2014 10:08

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