BioProject

A large gap in our understanding of infant immunity is why natural killer (NK) cell responses are deficient, which makes infants more prone to viral infection. More...

A large gap in our understanding of infant immunity is why natural killer (NK) cell responses are deficient, which makes infants more prone to viral infection. Here we demonstrate that transforming growth factor-beta (TGF-beta) was responsible for NK cell immaturity during infancy. We found more fully mature NK cells in CD11cdnR mice, whose NK cells lack TGF-beta receptor (TGF-beta R) signaling. Ontogenic maturation of NK cells progressed faster in the absence of TGF-beta signaling, which results in the formation of a mature NK cell pool early in life. As a consequence, infant CD11cdnR mice efficiently controlled viral infections. These data thus demonstrate an unprecedented role for TGF-beta in ontogeny that can explain why NK cell responses are deficient early in life. Overall design: Bone marrow cells were isolated from CD11cdnR (TG) and wild-type (WT) mice, and NK cells were sorted at different stages of development (stages D, E, and F) using BD Biosciences FACSAria. mNK cells from stages D, E, and F were obtained from three cell sorting analyses with samples pooled from n = 12 CD11cdnR and 25 WT mice. Equal amounts of total RNA from each stage was pooled prior to gene expression analysis. RNA was prepared using the RNeasy Micro kit (Qiagen), and cDNA was obtained using the standard protocol of reverse transcription. A customized StellARay cell cycle qPCR array (Lonza) was used. Quantitative gene expression analysis (quantitative PCR) was conducted on an ABI Prism 7900 instrument (Applied Biosystems). Less...