Viral Antigens

The mumps virus (MuV) is a single-stranded, negative-sense RNA virus with a genome approximately 15,000 nucleotides long . It encodes seven genes that produce nine proteins, including nucleocapsid (N), phosphoprotein (P), matrix (M), fusion (F), small hydrophobic (SH), hemagglutinin-neuraminidase (HN), and large (L) proteins . The virus is pleomorphic, with particles ranging from 100 to 600 nanometers in diameter . MuV primarily infects the upper respiratory tract and salivary glands .

The primary function of the mumps virus is to replicate within host cells, leading to the production of new virions . It plays a significant role in immune responses by evading host antiviral mechanisms, such as interferon production . The virus is recognized by the immune system, which mounts a response to control and eliminate the infection .

MuV binds to host cells via the HN protein, which attaches to sialic acid receptors on the cell surface . The F protein then facilitates the fusion of the viral envelope with the host cell membrane, allowing the viral genome to enter the cell . Inside the cell, the viral RNA-dependent RNA polymerase transcribes mRNA and replicates the genome, leading to the production of new virions . These virions bud from the cell surface, acquiring a lipid envelope from the host cell membrane .

The expression and activity of mumps virus proteins are regulated at multiple levels. Transcriptional regulation involves the RNA-dependent RNA polymerase, which transcribes mRNA from the viral genome . Post-translational modifications, such as glycosylation of the HN protein, are crucial for viral infectivity and immune evasion . The SH protein helps block NF-κB-mediated apoptosis, aiding in viral persistence .

In biomedical research, the mumps virus is used to study viral replication, immune evasion, and vaccine development . Diagnostic tools, such as reverse transcription-PCR, are employed to detect MuV in clinical samples . Therapeutically, the MMR vaccine is the primary strategy to prevent mumps infections . Research is ongoing to develop improved vaccines with enhanced efficacy .

Mumps virus plays a role throughout the human life cycle, from childhood to adulthood. Infection typically occurs in childhood, leading to lifelong immunity . The virus can cause complications such as orchitis, meningitis, and deafness, particularly in adolescents and adults . Vaccination has significantly reduced the incidence of mumps, but outbreaks still occur, highlighting the need for continued surveillance and vaccination efforts .