structure exhibiting (1) non-saturated fatty chains, (2) amide liaisons at the level of the disaccharide, and (3) a methylated
1-phosphate group and (4) lacks a 4
0 -phosphate group (Fig. 1)
[2, 3].
As a consequence of their peculiar structural properties, the
leptospiral LPS are recognized by the innate immune system in a
particular manner. First of all, and unlike other bacteria, the leptospiral lipid A is not recognized by the human toll-like-receptor
4 (hTLR4) although it is recognized by the murine toll-like-receptor 4 (mTLR4) [4]. In addition, it has been shown that leptospiral
LPS have the ability to activate the toll-like-receptor 2 (TLR2) [5],
independently of the lipid A moiety [4]. Such activity could be
attributed to the presence of lipoproteins that are known to activate
TLR2 and often co-purify with the LPS.
Two methods for leptospiral LPS purification have been
described: a rapid proteinase K purification and the classical hot
water/phenol extraction [6]. The choice of the purification
method depends on the intended use for the LPS. Indeed, the
proteinase K purification is appropriate to detect differences in the
O antigen. On the other hand, the hot water/phenol extraction is
advised for studying the immunological properties of the LPS, since
it requires purifying and separating the LPS from the rest of the
Fig. 1 Peculiar structure of the LPS of Leptospira interrogans. (Adapted from
Werts [3])
54
Delphine Bonhomme and Catherine Werts
1-phosphate group and (4) lacks a 4
0 -phosphate group (Fig. 1)
[2, 3].
As a consequence of their peculiar structural properties, the
leptospiral LPS are recognized by the innate immune system in a
particular manner. First of all, and unlike other bacteria, the leptospiral lipid A is not recognized by the human toll-like-receptor
4 (hTLR4) although it is recognized by the murine toll-like-receptor 4 (mTLR4) [4]. In addition, it has been shown that leptospiral
LPS have the ability to activate the toll-like-receptor 2 (TLR2) [5],
independently of the lipid A moiety [4]. Such activity could be
attributed to the presence of lipoproteins that are known to activate
TLR2 and often co-purify with the LPS.
Two methods for leptospiral LPS purification have been
described: a rapid proteinase K purification and the classical hot
water/phenol extraction [6]. The choice of the purification
method depends on the intended use for the LPS. Indeed, the
proteinase K purification is appropriate to detect differences in the
O antigen. On the other hand, the hot water/phenol extraction is
advised for studying the immunological properties of the LPS, since
it requires purifying and separating the LPS from the rest of the
Fig. 1 Peculiar structure of the LPS of Leptospira interrogans. (Adapted from
Werts [3])
54
Delphine Bonhomme and Catherine Werts