Host-directed clearance of nuclear tegument U14 terminates NF-κB signaling and supports HHV-6A replication

Innate immune and cellular stress responses triggered by infection must be transient and tightly controlled to restrain pathogens without harming the host. Herpesvirus infection induces NF-κB signaling through multiple viral and host inputs, yet how this response is terminated during productive infection remains unclear. Here, we identify a host-regulated timing mechanism that limits infection-associated NF-κB signaling during human herpesvirus 6A (HHV-6A) infection. The HHV-6A tegument protein U14 has the intrinsic capacity to induce NF-κB signaling and contributes to infection-associated NF-κB responses. The nuclear adaptor PDLIM2 associates with U14 and couples proteasome-dependent U14 turnover to phospho-p65 (Ser536) downregulation and NF-κB termination. CRISPRi-mediated PDLIM2 knockdown prolonged phospho-p65 (Ser536) signaling and nuclear U14 accumulation, enhanced antiviral and DNA damage-associated programs, increased γH2AX-marked nuclear stress, and reduced extracellular HHV-6A genome copies. Conversely, U14 knockdown attenuated viral gene expression, extracellular viral genome accumulation, and NF-κB-linked inflammatory gene induction. Collectively, these findings define the U14–PDLIM2 axis as a host-regulated mechanism that coordinates NF-κB termination with control of nuclear stress to support productive HHV-6A infection.