April 2012 | Volume 209, No. 4
Brief Definitive Reports
- Naive T cells are dispensable for memory CD4+ T cell homeostasis in progressive simian immunodeficiency virus infection
Memory CD4+ T cell homeostasis and AIDS progression are independent of naive CD4+ T cells in SIV infection of nonhuman primates.
- Histone H3 lysine 9 di-methylation as an epigenetic signature of the interferon response
Di-methylation of histone H3 at lysine 9 (H3K9me2) suppresses expression of interferon genes, and deletion or inactivation of the lysine methyltransferase G9a converts fibroblasts into interferon-producing cells resistant to RNA viruses.
- The ATPase activity of MLH1 is required to orchestrate DNA double-strand breaks and end processing during class switch recombination
MLH1 ATPase activity is essential for class switch recombination but not for somatic hypermutation.
- Notch, Id2, and RORγt sequentially orchestrate the fetal development of lymphoid tissue inducer cells
Notch signaling is required for the generation of α4β7+RORγt− fetal progenitors, but must then be turned off to allow RORγt expression and LTi cell maturation.
- The Mst1 and Mst2 kinases control activation of rho family GTPases and thymic egress of mature thymocytes
In mice lacking both Mst1 and Mst2 in the lymphoid compartment, thymocyte development is normal, but single-positive thymocytes exhibit excessive apoptosis and greatly diminished thymic egress, accompanied by loss of chemokine activation of RhoA and Rac1.
- Structural insight into MR1-mediated recognition of the mucosal associated invariant T cell receptor
Crystal structure and mutagenesis analyses suggest a MAIT TCR–MR1 docking mode distinct from the NKT TCR-CD1d docking mode.
- Essential role of EBF1 in the generation and function of distinct mature B cell types
Gain- and loss-of-function analyses reveal that the transcription factor EBF1 is required for normal differentiation and function of marginal zone, B-1, follicular, and germinal center B cells in mice.
- ATF3 protects against atherosclerosis by suppressing 25-hydroxycholesterol–induced lipid body formation
The transcription factor ATF3 inhibits lipid body formation in macrophages during atherosclerosis in part by dampening the expression of cholesterol 25-hydroxylase.
- Monocytes, neutrophils, and platelets cooperate to initiate and propagate venous thrombosis in mice in vivo
Deep vein thrombosis initiation is mediated by cross talk between monocytes, neutrophils, and platelets.
- The hypoxia imaging agent CuII(atsm) is neuroprotective and improves motor and cognitive functions in multiple animal models of Parkinson’s disease
The PET imaging agent CuII(atsm) improves motor and cognitive function in Parkinson’s disease.
- Cockayne syndrome group B protein prevents the accumulation of damaged mitochondria by promoting mitochondrial autophagy
Cells from Cockayne syndrome patients and a mouse model of the disease show increased metabolism as a result of impaired autophagy-mediated removal of damaged mitochondria.