Fibroblast interferon in man is coded by two loci on separate chromosomes

Area of Science:

• Immunology
• Genetics
• Cell Biology

Background:

• Interferon synthesis is crucial for antiviral defense.
• Understanding the genetic basis of interferon production is key to its therapeutic applications.
• Somatic cell hybridization offers a powerful tool to map genes and study gene regulation.

Purpose of the Study:

• To investigate the induction of interferon synthesis in various human, mouse, and Chinese hamster cell lines and their hybrids.
• To identify species and cell-type specific differences in interferon production.
• To map the genetic loci responsible for human fibroblast interferon synthesis.

Main Methods:

• Somatic cell hybridization of human, mouse, and Chinese hamster cells.
• Induction of interferon synthesis using viral and poly(rl):poly(rC) stimuli.
• Analysis of interferon production kinetics and inducer effectiveness.
• Gene mapping studies using human/mouse and human/Chinese hamster hybrid cells.
• Gene dosage experiments to determine gene location.

Main Results:

• Significant species and cell-type differences were observed in interferon inducer effectiveness and production kinetics.
• Parental interferon production characteristics were sometimes preserved, and sometimes modulated by epigenetic factors in hybrid cells.
• Human fibroblast interferon genes were mapped to chromosomes 2 and 5.
• Further analysis indicated one gene on the long arm of chromosome 2 and another on the short arm of chromosome 5.
• Leukocyte interferon genes could not be mapped to these chromosomes, possibly due to epigenetic influences.

Conclusions:

• Interferon production is regulated by complex genetic and epigenetic mechanisms.
• At least two distinct genes contribute to human fibroblast interferon synthesis, located on specific chromosomal regions.
• Somatic cell hybrids are valuable for dissecting the genetic control of interferon production and mapping interferon genes.