Interaction of feline sarcoma virus (FeSV) and mycoplasma

Area of Science:

• * Cell biology
• * Virology
• * Microbiology

Background:

• * Human glioma cell line U-251 MG supernatant contains a factor that inhibits feline sarcoma virus (FeSV) focus-forming activity.
• * This inhibitory activity was observed on feline embryo fibroblasts, a common indicator cell line in virology studies.

Purpose of the Study:

• * To identify the factor present in the U-251 MG cell supernatant that suppresses FeSV activity.
• * To investigate the mechanism by which this factor exerts its inhibitory effect.

Main Methods:

• * Supernatant from U-251 MG cells was analyzed to isolate the inhibitory factor.
• * The isolated factor was tested for its effect on FeSV focus-forming activity in feline embryo fibroblasts.
• * An antiserum against the identified factor was used to confirm its role in inhibition.
• * Cytopathic effects on glioma and indicator cells were assessed.

Main Results:

• * The inhibitory factor was identified as Mycoplasma arginini.
• * Enriched Mycoplasma arginini fractions showed no cytopathic effect on U-251 MG glioma cells or feline indicator cells.
• * An antiserum against Mycoplasma arginini effectively abolished the observed inhibition of FeSV activity.
• * Arginine depletion in the culture medium was suggested as a key factor in the inhibitory mechanism.

Conclusions:

• * Mycoplasma arginini is responsible for suppressing feline sarcoma virus focus-forming activity.
• * The inhibition mechanism is likely related to arginine depletion in the cell culture medium.
• * Mycoplasma arginini does not appear to be directly cytopathic to the tested cell lines.