Interferon acts directly on human B lymphocytes to modulate immunoglobulin synthesis

Area of Science:

• Immunology
• Cell Biology

Background:

• Interferon (IFN) is known for its antiviral properties.
• The role of IFN in regulating antibody synthesis by human lymphocytes is complex and context-dependent.

Purpose of the Study:

• To investigate the dual effects of interferon (IFN) on pokeweed mitogen (PWM)-induced immunoglobulin G (IgG) synthesis by human peripheral blood lymphocytes (PBL).
• To determine whether IFN acts directly on B cells or T cells to modulate IgG production.

Main Methods:

• Human peripheral blood lymphocytes (PBL) were treated with IFN before or during pokeweed mitogen (PWM) stimulation.
• PBL were separated into T and B cell subpopulations for co-culture experiments.
• Sephadex chromatography was used to isolate active fractions of IFN.

Main Results:

• Pretreatment with IFN significantly enhanced PWM-induced IgG synthesis by PBL, increasing production by over 100%.
• IFN's enhancing effect on IgG synthesis was primarily mediated through direct action on B cells, as evidenced by co-culture experiments.
• Conversely, the presence of IFN throughout the PWM assay suppressed IgG production.
• The IgG production-enhancing activity of IFN was localized to fractions possessing antiviral activity.

Conclusions:

• Interferon (IFN) exhibits a dual role in regulating antibody synthesis, with pretreatment enhancing and concurrent presence suppressing IgG production.
• IFN directly acts on B cells to augment antibody synthesis, highlighting its potential as an immunomodulator.
• The findings suggest that the timing and context of IFN exposure are critical in determining its impact on B cell function and humoral immunity.