Host range of mink cell focus-inducing viruses

Area of Science:

• Virology
• Molecular Biology
• Immunology

Background:

• Murine retroviruses, including xenotropic, amphotropic, and mink cell focus-inducing (MCF) classes, exhibit diverse host range properties.
• Understanding the species tropism of these viruses is crucial for studying retroviral pathogenesis and host-virus interactions.

Purpose of the Study:

• To determine the in vitro species host range of recombinant MCF murine retroviruses.
• To compare the host range of MCF viruses with that of xenotropic and amphotropic murine viruses.
• To elucidate the mechanism underlying MCF virus species host range determination.

Main Methods:

• In vitro infection assays using cell lines from various mammalian species.
• Phenotypic mixing experiments with xenotropic virus to assess envelope-cell surface interactions.
• Comparative analysis of MCF, xenotropic, and amphotropic virus infectivity.

Main Results:

• MCF viruses demonstrated a restricted host range, infecting cells from mouse, rat, mink, ferret, cat, and rabbit.
• Cells from Chinese hamster, buffalo, bat, dog, monkey, and human were resistant to most MCF viruses.
• Phenotypic mixing abrogated resistance in some resistant cells, indicating envelope-mediated entry.
• MCF isolates showed host range uniformity, distinct from xenotropic and amphotropic viruses.

Conclusions:

• MCF viruses represent a distinct class of murine retroviruses with a unique and restricted species host range.
• The species tropism of MCF viruses is primarily determined by virus envelope-cell surface interactions.
• These findings support the classification of MCF viruses as a separate group based on their distinct host range properties.