The clathrin endocytic pathway in viral infection

Area of Science:

• Virology
• Cell Biology
• Molecular Biology

Background:

• The clathrin-dependent endocytic pathway is a primary route for virus entry into host cells.
• Conflicting data exist regarding the necessity of this pathway for Semliki Forest virus (SFV), Sindbis virus, and picornaviruses like human rhinovirus 14 (HRV 14) and poliovirus.

Purpose of the Study:

• To investigate and clarify the role of clathrin-dependent endocytosis in the entry of SFV, Sindbis virus, HRV 14, and poliovirus into host cells.
• To determine if specific viruses utilize alternative entry pathways when clathrin-dependent endocytosis is inhibited.

Main Methods:

• Utilized a single-cell infection assay in HeLa cells.
• Employed overexpression of dynamin mutants to specifically inhibit clathrin-dependent endocytic pathway budding.
• Maintained low multiplicity of infection to favor the most efficient entry pathway.

Main Results:

• SFV, Sindbis virus, and HRV 14 infections were significantly impaired by the inhibition of clathrin-dependent endocytosis.
• Poliovirus infection of HeLa cells proceeded effectively even when the clathrin-dependent pathway was blocked.

Conclusions:

• Semliki Forest virus, Sindbis virus, and human rhinovirus 14 depend on the clathrin-dependent endocytic pathway for efficient host cell entry.
• Poliovirus utilizes an alternative, clathrin-independent pathway for infection, highlighting viral diversity in entry mechanisms.