Viral cell entry induced by cross-linked decay-accelerating factor

Area of Science:

• Virology
• Cell Biology
• Immunology

Background:

• Decay-accelerating factor (DAF) is a known attachment receptor for numerous human picornaviruses.
• Typically, DAF binding alone is insufficient for viral cell entry, requiring a secondary internalization receptor.
• DAF's proposed role is a sequestration receptor, holding viruses for subsequent interaction with functional receptors.

Purpose of the Study:

• To investigate if cross-linked DAF can function as a direct internalization receptor for human picornaviruses.
• To compare the CAV21 infection mechanism via cross-linked DAF versus ICAM-1.

Main Methods:

• Utilizing antibody cross-linking to modify surface-expressed DAF.
• Assessing coxsackie A21 virus (CAV21) infection mediated by cross-linked DAF.
• Analyzing the formation of A-type particles during CAV21 infection under different receptor conditions.

Main Results:

• Antibody-cross-linked DAF, unlike endogenous DAF, effectively mediates CAV21 lytic cell infection.
• CAV21 replication induced by cross-linked DAF occurs without the formation of detectable A-type particles.
• This contrasts with ICAM-1-mediated CAV21 infection, which generates high levels of A-type particles.

Conclusions:

• Cross-linked DAF can function as a direct, infectious virus receptor, distinct from its typical role.
• The mechanism of CAV21 infection via cross-linked DAF bypasses the need for A-type particle formation.
• This finding offers new insights into viral entry pathways and receptor function.