Specific unresponsiveness in nude mice given antigen before T cells

Area of Science:

• Immunology
• Cellular immunology
• Immune tolerance

Background:

• Specific immune tolerance can be induced in nude mice by antigen exposure followed by congenic T cell administration.
• Recovery of immune responsiveness after induced tolerance typically requires at least two weeks.

Purpose of the Study:

• To investigate the mechanism underlying long-term immune tolerance induced by antigen and T cells in mice.
• To determine if the unresponsiveness is mediated by T cells or other immune components.
• To explore methods for reversing established immune tolerance.

Main Methods:

• Induction of specific tolerance in nude mice using antigen and congenic T cells.
• Transfer of spleen cells from tolerant mice to irradiated congenic recipients with normal thymocytes.
• Treatment of spleen cells with supernatant from lysed cells prior to transfer.
• Assessment of recipient responsiveness to the antigen post-transfer.

Main Results:

• Recipients of spleen cells from tolerant mice, along with normal thymocytes, typically remained unresponsive.
• Treatment of tolerant spleen cells with lysed cell supernatant restored responsiveness in transfer experiments.
• Spleen cells from unresponsive mice did not suppress normal spleen cells in transfer.
• Unresponsiveness was not reversed by the presence of allogeneic cells.

Conclusions:

• The findings suggest that the induced unresponsiveness is likely due to a reversible blockade of B cell receptors.
• The results indicate that T cells are not the primary mediators of this specific type of immune tolerance.
• This reversible B cell receptor blockade offers a potential target for modulating immune responses.