Alveolar macrophages instruct CD8 T cell expansion by antigen cross-presentation in lung.

Lung CD8 memory T cells play central roles in protective immunity to respiratory viruses, such as influenza A virus (IAV). Here, we find that alveolar macrophages (AMs) function as antigen-presenting cells that support the expansion of lung CD8 memory T cells. Intranasal antigen administration to mice subcutaneously immunized with antigen results in a rapid expansion of antigen-specific CD8 T cells in the lung, which is dependent on antigen cross-presentation by AMs.

Celf1 regulation of dmrt2a is required for somite symmetry and left-right patterning during zebrafish development.

RNA-binding proteins (RBPs) bind to numerous and diverse mRNAs to control gene expression post-transcriptionally, although the in vivo functions of specific RBP-mRNA interactions remain largely unknown. Here, we show that an RBP named Cugbp, Elav-like family member 1 (Celf1) controls expression of a gene named doublesex and mab-3 related transcription factor 2a (dmrt2a), which is essential for somite symmetry and left-right patterning during zebrafish development. Celf1 promotes dmrt2a mRNA decay by binding to UGU repeats in the 3'UTR of dmrt2a mRNA such that celf1 overexpression reduces the amount of dmrt2a mRNA, leading to asymmetric somitogenesis and laterality defects.

Regulation of alternative splicing of alpha-actinin transcript by Bruno-like proteins.

Background: The Bruno-like or CELF proteins, such as mammalian CUGBP1 and Etr-3, Xenopus EDEN-BP, and Drosophila Bruno (Bru), are regulators of gene expression at the post-transcriptional level, and contain three RNA-recognition motifs (RRMs). It has been shown that mammalian CUGBP1 and Etr-3 regulate alternative splicing of cardiac troponin T pre-mRNA via binding to CUG-triplet repeats.

Results: Using in vitro selection and UV-crosslinking experiments, we found that zebrafish Bruno-like proteins bound to repeat elements of uridine and purine (termed UREs).