Recognition specificities, development and possible biological function of natural killer cells in the mouse. II. Changes in NK recognition during ontogeny and ageing, and examination of role of environment in controlling the expressed recognition repertoire.

We have used a spleen fragment assay to assess subpopulations of NK effector cells in individual mice and to analyse the patterns of inhibition of lytic activity seen in the presence of different sugars (mono-, di- and tri-saccharides). Our data suggest that during ontogeny the heterogeneity (diversity) of the NK effector population increases in a fashion which is somewhat characteristic of the individual strain under investigation. Furthermore, when a similar analysis was performed on NK cells in the spleen of lethally irradiated recipient mice receiving syngeneic or semi-allogeneic bone marrow stem cell precursors, we found that the phenotype of inhibition by different sugars was a characteristic of the bone marrow donor and not of the recipient. In so far as the assay described assesses target recognition by NK cells (and not subsequent parameters involved in the lytic event) these data can be interpreted in terms of a relative independence of the expressed recognition repertoire of NK cells from the environment in which their differentiation occurs.