Cell‐mediated cell lysis <i>in vitro</i>: genetic control of killer cell production and target specificities in the mouse

Abstract

Abstract The requirements for killer cell production in the course of a mixed leukocyte reaction and the specificity of target cell (PHA‐blasts) lysis in the mouse were investigated using inbred strains carrying intra‐ H ‐ 2 recombinant chromosomes. Strong lytic activity was generated in all, and only those, responder‐stimulator combinations which differed at either the H ‐ 2D or the H ‐ 2K , or both regions, even if the MLR incompatibility between responder and stimulator was very weak. Killing activity was specific and directed against determinants controlled by genes in the H ‐ 2K and H ‐ 2D regions. The slope of the killer dose‐response curves is the same for either type of specificity. Quantitative comparison of the lytic activity of a given killer cell population on different targets demonstrated a dose effect of the number of specificities recognized. No significant killing against the Ir or the Ss ‐ Slp regions of the H ‐ 2 complex could be detected. AntiH2 sera, if directed against the killer cells, do not inhibit their activity, while they can block killing, if directed against the target. This inhibition is specific in that a serum that blocks killing against the H ‐ 2K specificity of a given target does not inhibit the lytic activity directed against the H ‐ 2D determinants on the same target.