Objective: To observe the effect of the antibody to a B cell epitope on mouse Toll-like receptor-2 (mTLR-2) extracellular domain on the growth of murine fibrosarcoma.
Methods: An immunogen was prepared by conjugating a 20-mer peptide, synthesized on the basis of prediction for B cell dominant epitope of mTLR-2, to a carrier protein. Rabbit polyclonal antibodies against B cell epitope of mTLR-2 were prepared and purified, and characterized by Western blotting, immunohistochemistry and flow cytometry. Murine fibrosarcoma S180 cells were inoculated into the left hindlimbs of Swiss mice, and in the treatment group, the injected cells were mixed with 100 microg anti-mTLR-2 antibody TSP-1, with the same dose of irrelevant rabbit IgG in the IgG control group and with buffer solution only in the blank control group. The mice in each group were anesthetized and sacrificed on days 10, 14, and 18 following the injections, respectively, and the weight of the tumors was measured and the inhibition rate calculated.
Results: A distinct band for the antibody TSP-1 was shown at the relative molecular mass of 95 000 by Western blotting. The antibody TSP-1 could also react with native mTLR-2 expressed on J774A.1 cells, as identified by immunohistochemistry and flow cytometry. The growth of the fibrosarcoma S180 was obviously inhibited by injections with the antibody TSP-1 mixture, and the weight of tumor in mice treated with TSP-1 was significantly lower than that in the two control groups (P<0.05), with an inhibition rate of 77% on day 10, 51% on day 14 and 53% on day 18.
Conclusion: Local application of the antibody against B cell epitope on mTLR-2 extracellular domain can inhibit the growth of murine fibrosarcoma, especially in the early stage of tumor proliferation.