Viral Antigens

Key Biological Properties: Lassa virus is a single-stranded, bi-segmented RNA virus. It is enveloped and has a negative-sense RNA genome .

Expression Patterns and Tissue Distribution: The virus primarily infects endothelial cells, macrophages, and dendritic cells. It is found in multiple organ systems, including the liver, spleen, and kidneys .

Primary Biological Functions: Lassa virus is known for its role in causing Lassa fever, which can range from mild symptoms to severe hemorrhagic fever. It plays a significant role in immune response modulation and pathogen recognition .

Role in Immune Responses and Pathogen Recognition: The virus impairs cellular immunity, leading to fulminant viremia. It interacts with the host’s immune system, often leading to delayed or impaired immune responses .

Mechanisms with Other Molecules and Cells: Lassa virus enters host cells by binding to the alpha-dystroglycan receptor. Once inside, it hijacks the host’s cellular machinery to replicate and produce viral proteins .

Binding Partners and Downstream Signaling Cascades: The virus binds to alpha-dystroglycan on the cell surface, initiating a cascade of events that lead to viral replication and immune evasion .

Regulatory Mechanisms Controlling Expression and Activity: The replication of Lassa virus is regulated through an ambisense coding strategy, where genes are transcribed in both the sense and antisense directions. This allows for temporal control of viral protein production .

Transcriptional Regulation and Post-Translational Modifications: The virus uses host cellular machinery for transcription and translation. Post-translational modifications of viral proteins are crucial for the assembly and release of new virions .

In Biomedical Research: Lassa virus is studied extensively to understand viral hemorrhagic fevers and develop therapeutic strategies. Research focuses on vaccine development, antiviral drugs, and understanding the virus’s interaction with the host immune system .

Diagnostic Tools: Diagnostic methods include serological tests, PCR, and immunohistochemistry to detect viral antigens and RNA .

Therapeutic Strategies: Ribavirin is currently used as an off-label treatment for Lassa fever. Research is ongoing to develop more effective antiviral therapies and vaccines .

Role Throughout the Life Cycle: Lassa virus plays a critical role in the life cycle of its host, the multimammate rat (Mastomys natalensis). The virus is transmitted to humans through contact with contaminated rodent excreta. In humans, the virus can cause severe disease, particularly in pregnant women and immunocompromised individuals .