Mesenchymal stem cells stimulate antibody secretion in human B cells

Area of Science:

• Immunology
• Cell Biology

Background:

• Mesenchymal stem cells (MSC) are known for their immunomodulatory properties, including T-cell inhibition.
• The specific effects of MSC on human B cells, particularly antibody production, require further elucidation.

Purpose of the Study:

• To investigate the impact of MSC on human B-cell function, focusing on antibody secretion.
• To determine the role of cell contact and cytokine production in MSC-mediated B-cell responses.

Main Methods:

• Enzyme-linked immunospot (ELIspot) assays were used to measure IgG production in lymphocytes co-cultured with MSC.
• Experiments involved both unfractionated and enriched B cells, with and without cell contact.
• Interferon-gamma (IFN-gamma) and Interleukin-6 (IL-6) levels were measured.

Main Results:

• MSC significantly stimulated IgG production in lymphocytes, with varying effects based on stimulation type (LPS, viral antigens).
• Enriched B cells required direct cell contact with MSC for IgG production, while unfractionated cells showed stimulation even with a semipermeable membrane.
• MSC co-culture increased IFN-gamma and markedly elevated IL-6 levels.

Conclusions:

• Mesenchymal stem cells (MSC) promote B-cell antibody secretion.
• MSC's influence on activated B-cell IgG secretion is context-dependent, being either stimulatory or inhibitory based on the level of B-cell activation.