Histones interact with immunoglobulins and give them polyspecificity

Area of Science:

• Immunology
• Biochemistry

Background:

• Antihistone antibodies are found in various immunoglobulin preparations.
• Histones can influence interactions between immunoglobulins and charged biological molecules.

Purpose of the Study:

• To investigate the cofactor role of histones in the interaction of immunoglobulin preparations and sera with charged molecules.
• To determine if histone preincubation affects their cofactor function.
• To explore the implications of natural antibody-histone interactions for antibody polyspecificity.

Main Methods:

• Quantification of antihistone antibodies in commercial immunoglobulin preparations.
• Assays to assess the cofactor activity of histones in interactions with DNA, cardiolipin, and phosphatidylcholine.
• Preincubation experiments with histones and charged molecules.

Main Results:

• Histones significantly enhanced the interaction between immunoglobulin preparations/sera and charged molecules (DNA, cardiolipin, phosphatidylcholine).
• The cofactor effect of histones was diminished when they were preincubated with DNA or cardiolipin.
• A stable complex formed upon addition of histones to immunoglobulin preparations or serum samples.

Conclusions:

• Histones function as cofactors, mediating interactions between immunoglobulins and charged molecules.
• The binding affinity of histones to charged molecules influences their cofactor activity.
• Natural antibody interactions with histones may contribute to their observed polyspecificity.