[Receptors for the secretory component on human thymic lymphocytes. Stimulation of their expression as affected by adenosine, theophylline and a thymic lymphocyte supernatant]. / Retseptory dlia sekretornogo komponenta na limfotsitakh timusa cheloveka. Stimuliatsiia ikh ékspressii pri deistvii adenozina, teofillina i dekantata limfotsitov timusa.

It has been established by indirect immunofluorescence that thymic lymphocytes bear receptors for secretory component (Rsc). The bound secretory component, i. e., in the molecule of secretory IgA, was found to react with a greater number of thymocytes than free secretory component. Such difference may indicate that T-Rsc have higher affinity to the bound secretory component than to free secretory component. However, this needs detailed investigation. The ability of thymocytes to express Rsc depends on the cellular cAMP level, as the treatment with adenosine and theophylline increases the number of cells with Rsc. Supernatant of a 3-hour thymocyte culture was also capable of stimulating the expression of Rsc. It is assumed that secretory component contained in great amounts in the thymus membrane system takes part in the differentiation of T alpha and Tsc cells of the thymus, which repopulate lymphoid organs and regulate their immune reactions. Rsc may also be useful in assessing the state of Tsc subpopulation in different pathological conditions.

[Receptors for lactoferrin on human thymic lymphocytes. The stimulation of expression as affected by adenosine, theophylline and a supernatant of thymic lymphocytes]. / Retseptory dlia laktoferrina na limfotsitakh timusa cheloveka. Stimuliatsiia ékspresii pri deistvii adenozina, teofillina i dekantata limfotsitov timusa.

It was established by indirect immunofluorescence with the use of antibodies to human lactoferrin that thymic lymphocytes bear lactoferrin receptors in the point structures on the cell surface. The ability of thymic lymphocytes to express lactoferrin receptors depends on the cAMP concentration in the cell, inasmuch the treatment of lymphocytes with adenosine and theophylline increases the number of cells bearing lactoferrin receptors. Supernatant of thymic lymphocytes is also capable of stimulating expression of lactoferrin receptors. It is assumed that these treatments can be used for increasing the number of lymphocytes with lactoferrin receptors with the purpose of separation and study of the function of this subpopulation in health and in different pathological conditions.