Changes in IgG1 and IgG2a levels in serum
After 14 days of C. rodentium infection, serum samples were
collected, and ELISA was used to assess the changes in IgG1 and IgG2a
levels in mouse serum. Compared with the control group, the TS group
produced a strong IgG1 response (P <0.001) and a
low-level IgG2a response (P >0.05), with an increased
expression of IgG2a observed in serum from CR group mice
(P <0.05). This result showed that C. rodentiuminfection primarily induces a Th1-type immune response in mice, whileT. spiralis infection tended to induce a Th2-type immune
response. Compared with the CR group, the TS+CR group had increased IgG1
expression (P <0.01) and decreased IgG2a expression
(P <0.01), while compared with the TS group, the TS+CR
group exhibited increased IgG2a expression (P <0.01).
These results showed that the Th2 type immune response induced byT. spiralis inhibits the Th1 immune response caused by C.
rodentium infection (Fig. 5).