Beta-Endorphin as One of Important Integral Parts of Tactivin

Elizarova NL, Arion VYa, Kozlov VA*

Research Institute for Physico-Chemical Medicine, Moscow, Russia; *Institute of Clinical Immunology, Siberian Branch of Russian Academy of Medical Sciences, Novosibirsk, Russia

Russ. J. Immunol. 2001, October 15, 6 (3), 291-300

The discovery of opioid ligand, beta-endorphin (bEPh), in tactivin widens our knowledge about peptides synthesized by the thymus and allows to study new aspects of integration of the principal elements of immune and nervous systems within the integral immunoneuroendocrine network. Various produced lots of tactivin contain from 2 to 5 pM/l of bEPh which provides a number of properties of this preparation. bEPh is an important integral part of tactivin, as the action of tactivin «purified» of bEPh truly differs from the effects of the total preparation: both in the norm (57 healthy children) and in pathology (30 patients with pyelonephritis), these preparations acted in vitro in different ways on lymphocytes with phenotypes CD3+, CD4+, CD8+, CD38+, CD22+. Their influence on the functional activity of monocytes of the peripheral blood differed as well. All these effects of total tactivin and bEPh-free tactivin were partially realized through mu- and delta-opioid receptors. So, the removal of bEPh did not «liberate» tactivin from displaying opioid activity, and consequently tactivin contains not only bEPh, but also other ligands of mu- and delta-types. Tactivin produces a direct and pronounced effect on monocytes of peripheral blood of healthy people and patients. The sensitivity of immunocompetent cells to bEPh has been shown to be at the various levels and paradoxicality of action of this ligand may be related to the heterogeneity of receptors, through which bEPh reveals its influence. A wide range of biological activity of tactivin and bEPh with respect to standard parameters of healthy children is fair and its expediency is obvious as the immunocompetent cells of a healthy child can’t help reacting to the peptides incoming from the thymus into blood in cases of antigenic or non-specific responses. One can evaluate the «contribution» of bEPh to the size and importance of generalized effect of tactivin, as well as the role of intersystemic mediator bEPh probably may include the initiation and coordination of immunotropic and bioregulating properties of thymic preparation.