A cell membrane alteration specifically induced by SV40 transformation.

Area of Science:

• Cell Biology
• Virology
• Molecular Biology

Background:

• Simian virus 40 (SV40) is a DNA tumor virus known to alter host cell properties.
• Lipophilic antibiotics like Amphotericin B target cell membranes, often interacting with sterols.
• Understanding virus-induced cellular changes is crucial for cell biology and therapeutic development.

Purpose of the Study:

• To investigate the effect of SV40 transformation on cellular resistance to Amphotericin B.
• To determine if this resistance is specific to SV40 and its underlying genetic control.
• To elucidate the membrane alterations responsible for Amphotericin B resistance.

Main Methods:

• SV40 transformation of mouse 3T3 and human fibroblast cells.
• Assessing cell viability and resistance to Amphotericin B.
• Investigating Amphotericin B binding to transformed and untransformed cells.
• Evaluating the effect of cholesterol supplementation on Amphotericin B resistance.

Main Results:

• SV40 transformation specifically induced resistance to Amphotericin B in both mouse and human cells.
• This resistance was not observed with polyoma or mouse sarcoma virus transformations, indicating SV40 specificity.
• Resistance was not due to reduced antibiotic binding and could be partially reversed by cholesterol.
• Results suggest a modification in membrane sterol structure or a loss of a critical cholesterol fraction.

Conclusions:

• SV40 transformation induces a specific, genetically controlled membrane alteration conferring Amphotericin B resistance.
• The mechanism involves changes in membrane sterol composition, likely affecting antibiotic interaction.
• This finding provides a model for studying virus-induced membrane changes and their functional consequences.