The human cytomegalovirus chemokine binding protein UL22A is necessary for efficient reactivation from latency in CD34(+) hematopoietic progenitor cells and humanized mice

Summary

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus that infects 60%-90% of the population worldwide. In immunocompetent individuals, primary infection is asymptomatic and results in lifelong latent infection in CD34+ hematopoietic progenitor cells. Viral reactivation remains a major complication for immunosuppressed individuals, but current therapeutics targeting HCMV replication show significant toxicity. Thus, a better understanding of the mechanisms controlling latency and reactivation is necessary to develop new therapeutics targeting these stages of the HCMV lifecycle. UL22A is a chemokine-binding protein encoded by HCMV. Viral chemokine-binding proteins help regulate the host immune response and promote virus replication. We show that UL22A and its Y65 and Y69 residues are necessary for reactivation from latency in CD34+ hematopoietic progenitor cells and in a humanized mouse model. Additionally, we show that UL22A binding to its only known chemokine partner, RANTES (regulated on activation, normal T cell expressed and secreted), is not necessary for this reactivation phenotype. These findings suggest other novel functions for UL22A that we do not yet understand.

Authors Turner RL, Diggins NL, Slind L, Mitchell J, Pham AH, Parkins CJ, Perez W, Medica S, Denton M, Andoh TF, Webb GM, Andrade-Vera D, Streblow DN, Caposio P, Hancock MH
Journal Journal of virology
Publication Date 2026 Aug 18;100(8):e0061226
PubMed 42505120
PubMed Central PMC13483475
DOI 10.1128/jvi.00612-26

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