Recognition of polymorphic H-2 domains by T lymphocytes. I. Functional role of different H-2 domains for the generation of alloreactive cytotoxic T lymphocytes and determination of precursor frequencies
Abstract
In the present communication, the repertoire of alloreactive cytotoxic T lymphocytes (CTL) clones was quantitatively investigated by limiting dilution analysis and by target inhibition with a panel of monoclonal antibodies (mAb). These mAb have previously been shown to define two distinct alloantigenic domains, A and B, on the H-2Kk molecule. The Poisson distribution analysis of H-2Kk-specific CTL clones generated in a limiting dilution system revealed three CTL populations with different precursor frequencies. The high frequent population is suppressed by an unknown suppressive mechanism that allows less frequent CTL populations to become visible. Target inhibition studies with a panel of Kk-specific mAb showed that these CTL populations differ not only in their precursor frequency but also in their specificity for different H-2 epitopes on the Kk molecule. Thus clones of the high frequency population are almost exclusively specific for determinants within domain A. In contrast, the low frequency population displays predominant specificity for determinants of domain B, while the population with medium frequency is blocked equally well by mAb against either domains A or B. Each mAb blocked only a fraction of clones indicating t...Continue Reading