EMERGING THERAPEUTIC APPLICATIONS OF BACTERIAL EXOPOLYSACCHARIDES - Biomaterial Applications: Macro to Nanoscales - page 151

The immune modulatory effects are brought about by the interaction of
the immune cells and EPS component of the LAB. Exopolysaccharides
stimulate the antigen presenting dendritic cells through toll-like receptors
and leads to the augmentation of cellular immunity.
Exopolysaccharide produced by a bacterial strain (MK1) shows im-
munomodulatory effects by macrophage activation, increased phagocytic
index, secretion of TNF-α (tumor nechrotic factor), IL-1β (interleukin)
and nitric oxide release in mouse leukemia monocyte macrophage cell
lines (RAW-264.7) [50].
The EPS produced by Lactococcus lactis ssp. cremoris KVS20 T is ac-
tive as a B-cell mitogen in spleen cells isolated from C3H/HeJ mice [51].
Several other strains of Lactococcus lactis stimulate the production of IL's
and tumor necrotic factors (TNF) in vitro in macrophage cell lines J774.1
[52]. EPS produced by Lactobacillus rhamnosus RW-9595 M T [53], Lac-
tobacillus delbrueckii ssp. bulgaricus [12] and a thermotolerant strain of
Bacillus licheniformis [54] possesses immunomodulatory effects on im-
munocompetent cells in vitro. The immunomodulatory activity of the EPS
produced by Lactobacillus delbrueckii ssp. bulgaricus is due to the pres-
ence of functional phosphate group in the EPS [55]. The EPS produced
by Enterobacter cloacae Z0206 T enriched by the addition of selenium has
shown enhanced immunomodulatory activities in immuno compromised
mice [15] however, the exact mode of action of the EPS in immunomodu-
lation needs to be further explored so as to establish a stronger validation
of the activity.

TABLE 8.3 Chemical Composition of Some Bacterial EPS having Immunomodulatory

Activities

Bacteria Chemical composition of the EPS

MK1 Heteropolymer of glucose, rhamnose, galactose and

galactosamine MW ranging between 1.06 ´ 10 4 to 5.5
´ 10 4 Da [50].

Lactobacillus delbrueckii ssp.
bulgaricus 1073R-1 T

Phosphopolysaccharide of glucose and galactose [12].

Lactococcus lactis ssp. cremoris
KVS20 T

Phosphopolysaccharide of rhamnose, glucose and ga-
lactose [51].

Lactobacillus rhamnosus RW-
9595 M T

Heteropolymer of glucose, galactose and rhamnose
with functional acetyl groups [56].