A theory of self-nonself discrimination

Area of Science:

• Immunology
• Molecular Biology

Background:

• Humoral antibody formation depends on antigen recognition by antigen-sensitive cells.
• Immune tolerance and paralysis are critical for preventing autoimmunity.

Purpose of the Study:

• To elucidate the mechanisms of antibody induction and paralysis.
• To explain self-nonself discrimination based on immune cell interactions.

Main Methods:

• The study proposes a model based on antigen recognition by receptor and carrier antibodies on antigen-sensitive cells.
• It analyzes the competition between antibody induction and paralysis at the cellular level.

Main Results:

• Antibody induction requires dual determinant recognition (associative interaction), while paralysis involves single determinant recognition.
• High-zone paralysis occurs when both receptor and carrier antibodies are saturated, preventing associative interactions.
• Antigen interaction with receptor antibody induces a conformational change, leading to cell paralysis.

Conclusions:

• The proposed model explains immune responses, including tolerance to self-antigens, through specific deletion of antigen-sensitive cell activity.
• All antigens are considered thymus-dependent due to the requirement of carrier antibody for induction.
• Conformational changes in antibodies upon antigen binding are central to both immune activation and paralysis.