Дифференцированная циркадианная реакция на свет, проявляемая Т клетками и большими гранулярными лимфоцитами человека in vitro

Abstract

Recently we have shown that rhythmic daily fluctuations of the human blood lymphocyte ability to react with sheep erythrocytes (ER activity) persisted in lymphocytes placed in culture under the dark conditions or day-time illumination. If the illumination was switched over to the night- time, the inversion of this circadian rhythm was observed. The results implied that lymphocytic cells contained a self-sustained light-responsive circadian clock. As ER activity is characteristic of two lymphocyte subpopulations in human blood-T cells and large granular lymphocytes (LGL), we now studied the found circadian clock in enriched fractions of these lymphocyte subpopulati- ons, isolated and maintained in culture separately. It was established that although circadian variations of the lymphocyte activity were evident in both cell fractions, the rhythms turned out light-entrainable only in the LGL one. However, when the two lymphocyte subpopulati- ons were grown in a double-chambered vessel which allowed humoral exchange between them, T cell rhythms also became light-responsive, suggesting that a difusible element of the photo- receptive/circadian system could be transferred from LGL onto T lymphocytes through a half- permeable membrane. The findings are discussed in the context of an apparent key role of the LGL in the proposed mechanism of non-visual circadian photoregulation in man.