<p>A: Ten days after the infection, the frequency of activated B cells was
significantly higher in DENV/TLR group when compared to all other
groups, showing a synergistic effect of DENV with the TLR agonists in
this activation. DENV alone was able to induce activation of B cells
when compared to the TLR and Control groups. However, in our model, TLR
agonists alone were not sufficient to induce B-cell activation. B: The
activation profile of B cells correlates with the levels of anti-DENV
antibodies. Antibody levels were significantly higher in the DENV/TLR
group compared to the DENV group. C: As early as 10 days after infection
and coincident with activation of B cells, the switch to IgG1 was
significantly diminished in the DENV/TLR group. This difference had
disappeared by 15 days after the infection, but it was re-established on
day 30. D: Although antibody O.D. values were limited, the difference in
the IgG1 and IgG2 levels translated into a significant increase of the
IgG2/IgG1 ratio (>11 and 6 times on days 10 and 30 after the
infection, respectively). Asterisks denote significant differences,
(*) p<0.05, (**) p<0.01, and (***)
p<0.001.</p
