[Molecular aspects of immunoprotective activity of peptides in spleen during the ageing process].

Vilon, Timogen, Crystagen and R-1 short peptides possess various immunoprotective effects in spleen during its ageing. Both R-1 and Vilon peptides activate T-helpers. The effect of Vilon is provided by decreased level of apoptosis, as well as the effect of R-1 peptide is provided by increased proliferation and differentiation processes. Timogen activates B-cells by decreasing apoptosis level and increasing the proliferation of spleen cells. Crystagen also activates B-cells of the immune system; however, the peptide doesn't cause cell renewal in spleen as it ages.

A method of creation a cell monolayer based on organotypic culture for screening of physiologically active substances.

We developed a method of culturing and phenotyping of a monolayer of cells of the retinal tissue, thymus and spleen on the basis of organotypic culture. All characteristic types of neurons and fibroblasts were found in their microenvironment in the retinal cell monolayer. Lymphocytes, macrophages, and fibroblasts were verified in the monolayer of thymus and spleen cells. Histological staining, immunocytochemistry, and electron microscopy demonstrated the possibility of assessing the differentiation degree and functional activity of the cell monolayer. The developed technique preserves cell-cell interactions and a variety of cell types characteristic of the examined organ in the monolayer. This opens up new prospects for its application in basic research and in screening of different physiologically active substances.

Effect of tripeptide Lys-Glu-Asp on physiological activity of neuroimmunoendocrine system cells.

Tripeptide Lys-Glu-Asp stimulates proliferation and inhibits apoptosis in organotypic cultures of neuroimmunoendocrine system cells. Lys-Glu-Asp accelerates cell renewal processes (decrease of apoptosis marker p53 and increase of proliferation marker Ki-67) in the pineal gland; this effect is more pronounced in cultures derived from old animals than in young cultures. The tripeptide induces the expression of low-differentiated lymphocyte marker CD5 and macrophage marker CD68, but in "old" cultures this effect is less pronounced than in "young" ones. Thus, in tissue culture Lys-Glu-Asp primarily affects the nervous and endocrine tissues during aging and produces a less pronounced effect on the nervous tissue. Physiological activity of the tripeptide consists in modulation of associative learning of honey bee in the model of short-term and the long-term memory.

Peptidegic stimulation of differentiation of pineal immune cells.

We studied cell composition of the pineal lymphoid tissue and the effect of peptides on its differentiation and proliferation capacity. It was shown that the lymphoid component of the pineal gland in organotypic culture is primarily presented by low-differentiated CD5(+)-lymphocytes, while mature T and B cells are less abundant. Dipeptide vilon stimulates differentiation of precursors into T-helpers, cytotoxic T lymphocytes, and B cells, while tetrapeptide epithalon stimulated their differentiation towards B cells. Tripeptide vesugen had no effect on differentiation capacity of immune cells of the pineal gland, but enhanced their proliferation potential. Thus, dipeptide vilon acts as an inductor of differentiation of pineal immune cells, which can play an important compensatory role in age-related atrophy of the thymus, the central organ of the immune system.

Effect of short peptides on expression of signaling molecules in organotypic pineal cell culture.

We demonstrated the influence of short peptides on the expression of signaling molecules in organotypic culture of the pineal gland from 3-month-old rats. Peptides Ala-Glu-Asp-Gly and Lys-Glu-Asp stimulate the expression of proliferative protein Ki-67 in pineal gland culture. These peptides as well as Glu-Asp-Arg and Lys-Glu do not affect the expression of apoptosis marker AIF. The synthesis of transcription factor CGRP by pinealocytes was stimulated only by Ala-Glu-Asp-Gly. Thus, peptide Ala-Glu-Asp-Gly tissue-specifically stimulates proliferative and secretory activities of pinealocytes, which can be used for recovery of pineal gland functions at the molecular level.