TLR2 and Splenomegaly: H. hepaticus-induced innate immune typhlocolitis is accompanied by systemic activation of the innate immune system 39 and this was also unaffected by TLR2 genotype, as infected 129.RAG−/−.TLR2−/− mice had similar degrees of splenomegaly and granulocyte accumulation as infected 129.RAG−/−.TLR2+/+ littermates (Fig. 3B).