Modulation of polyclonal B cell differentiation by human leucocyte alpha interferon

Area of Science:

• Immunology
• Cell Biology
• Virology

Background:

• Interferon (IFN) plays a crucial role in animal immune responses, but its immunoregulatory functions in humans are less understood.
• Investigating the specific effects of human leucocyte alpha interferon (IFN alpha) on human immune cells is essential.

Purpose of the Study:

• To investigate the immunoregulatory activity of human leucocyte alpha interferon (IFN alpha) on human peripheral blood mononuclear cells (PBM).
• To determine the effect of IFN alpha on pokeweed mitogen (PWM)-induced immunoglobulin secretion and cellular proliferation in human PBM.

Main Methods:

• Peripheral blood mononuclear cells (PBM) from 20 healthy volunteers were cultured with pokeweed mitogen (PWM) in the presence or absence of human leucocyte alpha interferon (IFN alpha).
• Suppression of immunoglobulin secreting cells (IgSC) and proliferative responses were measured.
• IFN alpha's stability and specificity were assessed through pH and trypsin treatments, and delayed addition experiments.

Main Results:

• IFN alpha markedly suppressed PWM-induced immunoglobulin secreting cell (IgSC) generation in 18 out of 20 experiments.
• IFN alpha suppressed proliferative responses in all experiments, but this was not correlated with IgSC suppression.
• Suppressive activity was resistant to low pH but sensitive to trypsin, and delayed addition reduced suppression, indicating specificity and not non-specific cytotoxicity.

Conclusions:

• Human leucocyte alpha interferon (IFN alpha) demonstrates significant immunoregulatory activity on human B cell functions.
• IFN alpha suppresses both immunoglobulin production and proliferation of human PBM stimulated by mitogens.
• The findings confirm and extend previous knowledge on IFN's effects on PBM, highlighting its role in human immune regulation.