These toll-like receptor 7 targeted mutation mice may be useful in studies of viral immunity. Homozygotes demonstrate reduced responses to in vivo infection with vesicular stomatitis virus. This emphasizes the roll of the gene in viral recognition by plasmacytoid dendritic cells and B cells which activate costimulatory molecules and produce cytokines. No RNA expression is detected in bone marrow-derived macrophages by Northern blot analysis. The lacZ reporter introduced under the gene's promoter shows that within mesenteric lymph nodes, expression is normally confined to the perifollicular regions. Homozygotes are viable, fertile, have no obvious developmental problems, but are poor breeders for unknown reasons.

These toll-like receptor 7 (Tlr7) targeted mutation mice may be useful in studies of viral immunity. Homozygotes demonstrate reduced responses to in vivo infection with vesicular stomatitis virus. The lacZ reporter introduced under the gene's promoter shows that within mesenteric lymph nodes, expression is normally confined to the perifollicular regions. The Jackson Laboratory has two Tlr7 knock-in alleles available: the Tlr7 knock-in/knock-out allele with lacZ replacing exon 3 (Tlr7tm1Flv; Stock No. 008380) and the TLR7KI-tdTom knock-in allele with an IRES-tdTomato at the 3' end (Tlr7tm1.1Gbrt; Stock No. <a href="https://www.jax.org/strain/031827">031827</a>).