Gamma interferon induction in human thymocytes activated by lectins and B cell lines

Area of Science:

• Immunology
• Cell Biology
• Virology

Background:

• Human thymocytes, crucial for T-cell development, can produce interferons (IFNs).
• Interferon-alpha (IFN-alpha) is typically produced by B lymphoblastoid cells.
• Interferon-gamma (IFN-gamma) plays a key role in immune responses.

Purpose of the Study:

• To investigate the production of interferons by human thymocytes.
• To determine the effect of B lymphoblastoid cells on thymocyte interferon synthesis.
• To characterize the types of interferons produced in mixed cultures.

Main Methods:

• Human thymocytes were stimulated with lectins (concanavalin A, phytohemagglutinin).
• Thymocytes were cultured alone or with B lymphoblastoid cells (live, irradiated, or conditioned medium).
• Interferon types were identified by neutralization with specific antisera and pH stability.

Main Results:

• Lectin-stimulated thymocytes synthesized small amounts of interferon.
• B lymphoblastoid cells and their products significantly enhanced interferon production by thymocytes.
• The enhanced interferon produced in mixed cultures was identified as IFN-gamma, while B cells produced IFN-alpha.

Conclusions:

• Human thymocytes synthesize IFN-gamma upon lectin stimulation.
• B lymphoblastoid cells and their products potently stimulate IFN-gamma synthesis by thymocytes.
• The stimulatory effect is independent of IFN-alpha produced by B lymphoblastoid cells.