Similarly, microglia are the target cells in brains of mice with neonatal listeriosis, inducing a TNF-α-mediated transcriptional program of cell suicide that up-regulates early macrophage signaling via tlr1, tlr2, tnf-α, nfkB, cd14 and mapk1 genes with low induction of ccl3 and ccl5 chemokine genes, which suggests poor recruitment of monocytes to the brain compared to during systemic listeriosis [47]. This evidence concerns the gene TLR1 and listeriosis.