Archived

This content is available here for research, reference, and/or recordkeeping.

Author ORCID Identifier

https://orcid.org/0009-0005-7561-1855

Date Available

7-27-2026

Year of Publication

2026

Document Type

Doctoral Dissertation

Degree Name

Doctor of Philosophy (PhD)

College

Medicine

Department/School/Program

Molecular and Cellular Biochemistry

Faculty

Rebecca E. Dutch

Faculty

Trevor P. Creamer

Abstract

Human metapneumovirus (HMPV) causes severe respiratory tract infections in all cohorts, but especially in vulnerable groups such as children, older adults, and the immunocompromised. The matrix (M) protein of HMPV, like the M proteins of other members of the Mononegavirales order, is involved in virus assembly and budding. However, other functions of the HMPV M protein have yet to be elucidated. To investigate these various functions of the M protein, we used a peptide-conjugated phosphorodiamidate morpholino oligomer (PPMO) antisense agent designed to block translation of the M gene to reduce M expression during infection. Treatment with varying concentrations of an HMPV M mRNA-targeted PPMO (PPMOM) led to dose-dependent decreases in M expression. A 10 µM PPMOM treatment applied at 1 hour post-infection (hpi) led to a >95% reduction in M protein at 24 hpi. Infected cells treated with PPMOM at different times and doses showed a decrease in long viral filaments, decreased budding, and a change in fusion (F) protein distribution. HMPV vRNA distribution was also altered when treated with PPMOM. In control-treated infections, vRNA was localized in inclusion bodies (IBs) and at the cell periphery; but when M was reduced, there was an increase in the number of IBs per cell and a decrease in average IB volume per cell at 12 and 24 hpi. This change in IB properties was not observed when varying amounts of M were transfected with HMPV N and P. HMPV-infected cells treated with PPMOM exhibited lower levels of phosphoprotein (P) at the plasma membrane and no change in viral ribonucleoprotein (vRNP) movement, suggesting M participates in the late stages of vRNP trafficking. This study helps elucidate a previously poorly understood role for M-mediated vRNP association at the plasma membrane.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2026.362

Archival?

Archival

Funding Information

This study was funded by the University of Kentucky, College of Medicine Rebecca Dutch Discretionary Fund.

Download

Share

COinS