Structure of Hepatitis C

Hepatitis C virus (HCV) is a hepacivirus of the family Flaviviridae, according to the Viral Hepatitis Prevention Board (VHPB). It is an RNA virus with an envelope. Proteins on its surface help an HCV virus particle (called a virion) to bind to and infect host cells; once it is brought within a host cell, it replicates (creates more copies of itself).

External Structure

• The outermost layer of HCV is its envelope, composed of lipids (fats). This layer of the virus is derived from host cells, according to Microbiology and Immunology Online. Embedded in the envelope are two glycoproteins, labeled E1 and E2, according to the VHPB. A single HCV virion is between 30 and 60 nanometers wide.

Internal Structure

• Contained within the envelope is the nucleocapsid which is composed of the core protein, called p21, according to the VHPB. The nucleocapsid contains the virus' genetic material, which is a single strand of RNA (ribonucleic acid).

Infection

• HCV infects cells of the liver, called hepatocytes. The glycoproteins on its surface, E1 and E2, sense and bind to receptor sites on host cells, and the virion is absorbed into the host cell, according to the VHPB. The core protein is cleaved, and the virus' RNA is released into the host cell's cytoplasm, according to the VHPB.

Replication

• Interaction of viral RNA and enzymes as well as host-cell enzymes with the host cell's ribosome cause the production of new viral proteins, according to the VHPB. The new viral components (proteins and RNA) are repackaged into new envelopes derived from the host cell to form new virions.

Effects

• After the virus replicates, it is released from the host cell. These new virions go on to infect other cells, continuing the process of infection, according to the VHPB. Infection with HCV leads to both acute and, commonly, chronic infections. The antiviral drugs interferon and ribavirin are commonly used to combat chronic HCV infection, according to the Centers for Disease Control and Prevention (CDC).