S. A. Bobrovnik, M. A. Demchenko, S. V. Komisarenko

Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: s-bobrov@bk.ru

A previously unknown phenomenon of acquired polyreactivity of serum immunoglobulins, which were subject to the effect of concentrated solutions of chaotropic ions, such as KSCN (3.0-5.0 M), low/high pH (pH 2.2-3.0), or heating to 58-60 °C, was originally described by the authors in 1990. Eleven years after that, similar data were published by J. P. Bouvet et al.(2001), which confirmed completely our results concerning the influence of either chaotropic ions or drastic shift of pH on polyreactive properties of immunoglobulins. Our further investigations (1993, 1995, 1998) of polyreactive serum immunoglobulins (PRIG) properties have revealed that the mechanism of nonspecific interaction between PRIG and antigens much differs from the mechanism of interaction between specific antibodies and corresponding antigens. Later we have shown that the increase in PRIG reactivity could be induced in vivo (1999) and PRIG are one of serum components of human or animal sera. Then, it could be suggested that PRIG may perform certain biological functions. Studying PRIG’s effect on the phagocytosis of microbes or on the tumor growth (S. A. Bobrovnik et al., 1995, 1998) have revealed that PRIG may play a certain role in protecting the body from infections and probably may influence the development of various pathological processes. Recently we also found (S. A. Bobrovnik et al., 2014) that IgG PRIG content significantly increases in aged people. These data demonstrate that further investigations of PRIG’s immunochemical properties and study of their biological role in organism protection from various diseases is very important.

Keywords: affinity, antigens, avidity, natural antibodies, polyreactive immunoglobulins, specificity