Pathological and inflammatory cytokine changes in EAE
The main pathological changes in MS are inflammation and demyelination
in the white matter of the CNS, axonal injury and axonal loss, which can
coexist and are often associated with diffuse lesions of the
CNS[21]. As shown in Figure1c, a
small number of monocyte and lymphocyte infiltrations could be seen in
the spinal cord of EAE mice, with obvious perivascular inflammatory
infiltrations by HE stainings. LFB stainings showed demyelination in the
spinal cord.
The pro-inflammatory cytokines, IL-17A, IL-6, TNF-α, IL-12p70 and IL-1ß
increased at the disease onset(P<0.0001) and IL-17A, IL-6,
TNF-α, IL-12p70 decrease at the peak hour(P<0.0001). While
anti-inflammatory cytokines, IL-4 and IL-10, significantly increased
during the peak period(P<0.001)(Figure1d).
Clinical course,
pathological and inflammatory cytokine changes after M2 macrophage
treatment
The proportion of M2 macrophages
cultured in vitro was more than 97% determined by flow
cytology(Figure 2a). Those were transfused into the mice when EAE mice
showed clinical symptoms on day 10 p.i.(onset). EAE treated with M2
macrophage(M2-treated) and PBS developed the disease at the same time;
however, the peak symptoms were lighter and recovered earlier in the
M2-treated group than controls. Similarly, weight records of the two
groups showed that the weight gradually decreased in the EAE control
group until day 22p.i. and dropped to the lowest at the peak phase;
while M2-treated group had lost weight until day 17p.i. and then their
weight increased gradually. On day 22 p.i., EAE symptoms reached a peak
with average scores of 3.08±0.20. The M2-treated group showed the
highest score on day 17 p.i., with an average score of
2.36±0.26(P<0.0001)(Figure 2b).
During the peak hour, the spinal cord was removed for pathological
staining after perfusion. As shown in Figure 2c, the inflammatory cell
infiltrations in spinal cords were less in the M2-treated group than in
EAE control group measured by HE staining(P<0.0001). LFB
staining showed that spinal demyelination in the M2-treated group was
significantly less severe than that in the EAE control
group(P<0.0001).
Additionally, pro-inflammatory cytokines, IL-6, IL-17A, TNF, IL-1ß and
IL-12p70, are lower in the M2-treated group compared with the
controls(P<0.01). Anti-inflammatory cytokines, IL-4 and IL-10
are higher in M2 treated group(P<0.01)(Figure 2d).