0000000000236129
AUTHOR
Ramin Massoumi
Regulation of B cell homeostasis and activation by the tumor suppressor gene CYLD
B cell homeostasis is regulated by multiple signaling processes, including nuclear factor-kappaB (NF-kappaB), BAFF-, and B cell receptor signaling. Conditional disruption of genes involved in these pathways has shed light on the mechanisms governing signaling from the cell surface to the nucleus. We describe a novel mouse strain that expresses solely and excessively a naturally occurring splice variant of CYLD (CYLD(ex7/8) mice), which is a deubiquitinating enzyme that is integral to NF-kappaB signaling. This shorter CYLD protein lacks the TRAF2 and NEMO binding sites present in full-length CYLD. A dramatic expansion of mature B lymphocyte populations in all peripheral lymphoid organs occur…
Mutated cylindromatosis gene affects the functional state of dendritic cells
Cylindromatosis gene (CYLD) is a ubiquitously expressed deubiquitinating enzyme, which interacts with members of the NF-κB signaling pathway and attenuates NF-κB and JNK signaling. Here, we report that DC derived from transgenic mice, which solely express a naturally occurring CYLD isoform (CYLD(ex7/8)), display a higher content of nuclear RelB and express elevated levels of NF-κB family members as well as of known NF-κB-target genes comprising costimulatory molecules and pro-inflammatory cytokines, as compared with WT DC. Accordingly, unstimulated CYLD(ex7/8) DC exhibited a significantly higher primary allogenic T-cell stimulatory capacity than WT DC and exerted no tolerogenic activity. Tr…
Naturally occurring short splice variant of CYLD positively regulates dendritic cell function
Abstract Deubiquitination of NF-κB members by CYLD is crucial in controlling the magnitude and nature of cell activation. The role of the naturally occurring CYLD splice variant in dendritic cell (DC) function was analyzed using CYLDex7/8 mice, which lack the full-length CYLD (flCYLD) transcript and overexpress the short splice variant (sCYLD). Bone marrow–derived DCs from CYLDex7/8 mice display a hyperactive phenotype in vitro and in vivo and have a defect in establishing tolerance with the use of DEC-205–mediated antigen targeting to resting DCs. The combination of sCYLD overexpression and lack of flCYLD in CYLDex7/8 DCs leads to enhanced NF-κB activity accompanied by an increased nuclear…