CELLULAR COMPONENTS OF THE IMMUNE SYSTEM, INCLUDING CYTOTOXIC T CELLS, MACROPHAGES, AND NATURAL KILLER CELLS, ARE CAPABLE OF THE DIRECT DESTRUCTION OF A VARIETY OF TARGETCELLS INCLUDING ALLOGENIC CELLS AND VIRUS-INFECTED OR MALIGNANT CELLS WITHIN THE

CELLULAR COMPONENTS OF THE IMMUNE SYSTEM, INCLUDING CYTOTOXIC T CELLS, MACROPHAGES, AND NATURAL KILLER CELLS, ARE CAPABLE OF THE DIRECT DESTRUCTION OF A VARIETY OF TARGETCELLS INCLUDING ALLOGENIC CELLS AND VIRUS-INFECTED OR MALIGNANT CELLS WITHIN THE HOST INDIVIDUAL. RESEARCH ON THESE CELLULAR CYTOTOXICITY REACTIONS, THEIR MODULATION IN AVARIETY OF DISEASE STATES, AND THEIR REGULATION BY A NUMBER OF NATURAL AND SYNTHETIC SUBSTANCES IS BEING VIGOROUSLY PURSUED IN LABORATORIES THROUGHOUT THE WORLD. TO DATE, CELLULAR CYTOTOXICITY REACTIONS ARE MONITORED ALMOST EXCLUSIVELY BY THE 51CR-RELEASE MICROCYTOTOXICITY ASSAY, WHICH IS EXPENSIVE AND TIME-CONSUMING. THIS PROJECT IS PROPOSED TO DEVELOP A SIMPLE, RAPID, AND RELATIVELY INEXPENSIVE NONISOTOPIC ASSAY FOR CELLULAR CYTOTOXICITY REACTIONS BASED UPON QUANTITATION OF INTRACELLULAR ANTIGENS RELEASED FROM DAMAGED TARGET CELLS IN AN ENZYME IMMUNOASSAY.IN PHASE I, POLYCLONAL ANTISERA TO CYTOSOL PREPARATIONS WILLBE PREPARED FROM HUMAN LEUKOCYTES AND CERTAIN HUMAN CELL LINES. THE IGG FRACTION OF THE ANTISERA WILL THEN BE CONJUGATED TO HORSERADISH PEROXIDASE OR BETA-GALACTOSIDASE. ENZYME IMMUNOASSAY CYTOTOXICITY (EIC) REACTIONS EMPLOYING THESE REAGENTS AND HUMAN NATURAL KILLER CELLS OR CYTOTOXIC TCELLS GENERATED IN IN VITRO MIXED LYMPHOCYTE CULTURES WILL BE COMPARED TO STANDARD 51CR-RELEASE METHODS. IF THE SENSITIVITY, SPECIFICITY, AND LINEARITY OF EIC REACTIONS PROVE COMPARABLE OR SUPERIOR TO THOSE OF 51CR-RELEASE ASSAYS, THE GOAL OF PHASE II RESEARCH WILL BE DETERMINATION OF THE BEST COMBINATION(S) OF ANTISERA, THAT IS SUFFICIENTLYSIMPLE, SENSITIVE, AND QUANTITATIVE FOR USE IN THE ROUTINE CLINICAL MONITORING OF CELLULAR IMMUNE FUNCTION.