Integrated transcriptomics and gene network analysis in the spleen and skin reveal tissue-specific roles for the conserved herpesvirus protein kinase (CHPK) during Marek’s disease virus replication in chickens

Authors: AKBAR, HAJI - University Of Illinois; PONNURAJ, NAGENDRAPRABHU - University Of Illinois; VOLKENING, JEREMY - Base2bio; SHUAIB, MUHAMMAD - King Abdullah University Of Science And Technology; BIONAZ, MASSIMO - Oregon State University; Spatz, Stephen; JAROSINSKI, KEITH - University Of Illinois

Submitted to: Journal of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/13/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: To survive and spread, herpesviruses need special enzymes. The conserved herpesvirus protein kinases (CHPKs), an essential viral protein that plays a pivotal role in the life cycle of herpesviruses, is one of these enzymes. It’s like the virus's secret weapon, helping it to grow, multiply, and jump from one host to another. We are studying a specific virus that affects chickens, called Marek's disease virus (MDV), a highly contagious herpesvirus that affects poultry, and compared a normal MDV with one that was missing the CHPK gene. We found that CHPK significantly impacts viral pathogenesis and is crucial for the virus to cause disease. In the chicken's spleen, CHPK regulates the expression of host genes involved in immune response, cell cycle progression, and metabolic processes. These genes help the virus to hide from the chicken's immune system and to keep them multiplying. CHPK also seem to have a special role in the skin. They can alter other proteins through post-translational modifications by the addition of phosphates, through a process called phosphorylation. In the skin this process might help the virus to hide and spread to other chickens. By understanding how CHPK works, we hope to find ways to stop viruses from spreading and causing disease.

Technical Abstract: Conserved herpesvirus protein kinases (CHPK) are found in all members of conserved among the Orthoherpesviridae. CHPK is dispensable for Marek’s disease herpesvirus (MDV) replication in cell culture and during experimental infection in chickens but is essential for horizontal transmission from chicken to chicken. The precise role CHPK plays during replication and horizontal transmission in the host is unknown. This study aimed to investigate CHPK’s role in cellular gene expression during natural infection in the epithelial skin and spleen cells using RNA sequencing and mass spectrometry. We hypothesized that 1) MDV alters cellular gene expression in both tissues, 2) the responses differ significantly between the spleen and skin, and 3) CHPK regulates these changes. To test these hypotheses, we collected epithelial skin and spleen tissues from chickens infected with wild-type MDV (vCHPKwt) or a CHPK-null MDV (v'CHPK). RNA sequencing identified significant differences in cellular gene expression when comparing mock- and vCHPKwt-infected tissues. Notably, differences were more pronounced in the spleen, while the skin exhibited minimal changes. Functional enrichment analysis revealed that vCHPKwt infection significantly impacted both tissues' immune responses, membrane transport, cell cycle regulation, and metabolic processes. Comparisons between v'CHPK and vCHPKwt in the spleen showed alterations in cellular interactions and immune system pathways. Additionally, mass spectrometry analysis of proteins in the skin uncovered significant post-translational modifications related to translational pathways. Our findings demonstrate that CHPK plays a vital role in regulating cellular processes in the spleen at the transcriptional level while having a lesser impact on gene transcription in skin cells. Instead, CHPK appears to influence cellular pathways post-transcriptionally, particularly through protein phosphorylation. This study highlights the essential role of CHPK in herpes viral transmission from host to host.