Histones evoke thymocyte death in vitro; histone-binding immunoglobulins decrease their cytotoxicity.

Effects of various histones, poly-L-lysine, spermine, and the synthetic peptide Arg-Lys-Asn-Val-Tyr-Arg (thymohexine) on intact rat thymocytes were studied. Histones and poly-L-lysine displayed cytotoxicity, causing disorders in the membrane permeability of thymocytes and their death. The dose and time dependences of the effects of histones on thymocytes were determined.

[Natural antihistone antibodies: their possible role in genesis of radiation injuries].

The substantial decrease of free natural antibodies reacting with histones under effect of 4 Gy total dose radiation in sera of healthy animals was established. It is supposed that the binding of natural antihistone antibodies with histones reduces the cytotoxic reactivity of histones released from cells under effect of ionizing radiation. It was determined that complexes of antihistone antibodies and histones get the ability to react with DNA.

Histones interact with immunoglobulins and give them polyspecificity.

The presence of antihistone antibodies was determined in different commercial immunoglobulin preparations. The ability of histones to perform the function of cofactor in interaction of immunoglobulin preparations and sera of healthy people with charged molecules such as DNA, cardiolipin and phosphatidylcholine, was determined. The addition of histones of immunoglobulin preparations or serum samples is accompanied by forming the stable complex, components of which interact with the charged molecules.