Anti-complementary amines are immunological adjuvants in mice

Area of Science:

• Immunology
• Biochemistry

Background:

• Complement system plays a crucial role in innate and adaptive immunity.
• Amine compounds can modulate immune responses.
• Understanding the interaction between amines and complement is vital for immune modulation.

Purpose of the Study:

• To investigate the complement (C) inactivating properties of ammonia, ethylenediamine, and methylamine in mouse serum.
• To explore the potential adjuvant effect of these amines in cell-mediated immune responses.
• To establish a correlation between complement inactivation and the observed adjuvant effects.

Main Methods:

• In vitro assessment of complement activity (alternative pathway and overall) in mouse serum following amine treatment.
• Evaluation of adjuvant effects in the delayed type hypersensitivity response in mice using sheep red blood cells (SRBC).
• Statistical analysis to determine the correlation between complement activity inhibition and adjuvanticity.

Main Results:

• Ammonia, ethylenediamine, and methylamine demonstrated a dose-dependent depletion of both alternative pathway (AP) and overall complement activity.
• These amines exhibited significant adjuvant effects in the delayed type hypersensitivity response.
• A strong positive correlation (r = 0.9995) was found between the inhibition of AP activity and adjuvanticity, suggesting a causal link.
• Both complement inactivation and adjuvant effects were directly related to the number of amino groups per molecule.

Conclusions:

• The study suggests a causative relationship between amine-induced complement inactivation and their observed immunological adjuvant effects.
• The findings exclude direct phagocyte inhibition as a primary mechanism for the immuno-adjuvanticity of these amines.
• A proposed mechanism involves prolonged antigen persistence and enhanced presentation due to local complement depletion.