Serum modulates mast cell responses to IgE antigen stimulation

Area of Science:

• Immunology
• Molecular Biology
• Cell Biology

Background:

• Serum, specifically fetal calf serum (FCS), influences gene expression, including the fos and jun gene families encoding transcription factor AP-1.
• Previous research indicated that IgE-antigen stimulation in mast cells induces mRNA accumulation of c-fos, c-jun, junB, and junD proto-oncogenes.

Purpose of the Study:

• To investigate the effect of serum on proto-oncogene mRNA accumulation in mast cells.
• To determine if serum modulates the inhibition of DNA synthesis in immunologically stimulated mast cells.

Main Methods:

• Mast cells were cultured with and without fetal calf serum (FCS).
• Proto-oncogene mRNA levels (c-fos, c-jun, junB, junD) and DNA synthesis rates were measured.
• Immunological stimulation (IgE-antigen) was applied to FCS-deprived mast cells.

Main Results:

• Mast cells cultured with FCS exhibited high proliferation and increased mRNA for c-fos, junB, and junD.
• FCS deprivation led to decreased DNA synthesis and c-fos mRNA levels, while other jun mRNAs remained unaffected.
• Immunological stimulation of FCS-deprived mast cells resulted in DNA synthesis inhibition and elevated c-fos expression.
• Both IgE-antigen and FCS increased c-fos mRNA to similar levels, without synergistic effects.

Conclusions:

• Fetal calf serum (FCS) promotes mast cell proliferation and proto-oncogene mRNA accumulation.
• Serum deprivation alters mast cell responses to immunological stimuli, affecting DNA synthesis and c-fos expression.
• Changes in DNA synthesis induced by FCS can prevent immunological challenges from inhibiting mast cell growth and enhancing c-fos mRNA.