TLRs 7 and 8 recognize guanosine and uridine- (GU-) rich or U-rich
ssRNA sequences [113, 114].
This evidence points to a delayed cell response, which seems to be dependent on the presence of several
ssRNA molecules which only happens after the virus initiated replication within the host cell.
For instance, it has been shown that lipopolysaccharides (LPS), a TLR4 agonist, and
ssRNA (TLR7 and TLR8 ligands) accelerate pancreatic carcinogenesis [11, 12].
ssRNA viruses may also impart protection to hosts by integrating portions of viral RNA into the host's genome (Valles 2011) which has been reported for SINV-1(TX5) (Tufts et al.
(39) Two highly conserved regions on the HCV's
ssRNA genome have been exploited for genotyping by various commercial assays using direct sequence analysis.
In this example, the molecules of interest were aptamers [single-stranded DNA or RNA (ssDNA or
ssRNA) molecules that bind with high affinity and specificity to proteins and peptides etc.] and ligands.
The genome of PRSV consists of 800-900 nm long nonenveloped flexuous filamentous particles with an
ssRNA genome of about 10,324 nucleotides [27].
DGCR8 an important cofactor is required for the processing of pri-miRNA and is believed to recognize the cleavage site between
ssRNA and stem of pri-miRNA.
HCV is a member of the Flaviviridae family that bears approximately 10 kb long positive sense single-stranded RNA (
ssRNA) genome.
The genome consists of three linear
ssRNA molecules [9].
On another side, upon viral infection, TLR7 recognizes
ssRNA viral nucleic acid released in intracellular acidic compartments of phagocytes, which take up virus infected cells and mount appropriate anti-viral innate immune response by inducing type I interferons (Diebold et al., 2004).