re PAMP andnot a constituent of host cell . Since unmethylated CpG motifs are present in the vector DNA, increased mRNA for TLR9 was observed. However, vaccine DNA transfected cells did not show increase in TLR 9 could be due to FMDV VP1 antigen if contributed for the down regulation of TLR 9 in FMDV infected cells, may be the same antigen carried by the DNA vaccine reduced expression of TLR 9 in cells but not significantly. Because in vivo replication of virus lead to more antigen expression in FMDV infected cells. Other possibility could be most RNA viruses have evolved strategies to sequester dsRNA by a variety of mechanisms to avoid activation of these antiviral pathways  and down regulation of TLRs might have important immunosuppressive effect  or viral persistence which is also observed in FMDV after the natural infection .
Our investigation showed very interesting results, showing TLR 2 is up regulated in FMDV infection and FMD DNA vaccine transfection conditions which contribute the antigen. However, major difference of up regulation of TLR 3 & 4, down regulation of TLR 9 observed in FMDV infection needs more studies to support the claim made in this report.
We are grateful to Department of Biotechnology for the financial support. The authors thank the Director, IVRI and the Joint Director for the facilities provided for carrying out this work.
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