A NEW MARKER FOR RETROVIRUS-INFECTED LYMPHOCYTES

THE LONG-TERM OBJECTIVE IS TO DEVELOP REAGENTS THAT WILL INDICATE THE EXTENT OF, OR MAY INTERVENE IN, THE TRANSFORMATION OF HUMAN LYMPHOCYTES INFECTED BY RETROVIRUSES. THIS STUDY IS BASED ON RECENT FINDINGS THAT HUMAN T-CELL LINES NORMALLY EXPRESS A 5.5-KB MRNA THAT CODESFOR THE MITOGENIC FORM OF THE PLATELET-DERIVED GROWTH FACTOR (PDGF-BB). THIS RECEPTOR (PDGFR-B) IS LOCALIZED ON THE CELL SURFACE. HOWEVER, HTLV-I-INFECTED T-CELL LINES EXPRESS ONLY A 4.8-KB PDGFR-B MRNA THAT CODES FOR A PROTEIN THAT IS LOCALIZED INTRACELLULARLY. AN IDENTICAL 4.8-KB PDGFR-B MRNA HAS BEEN DETECTED IN ONE HIV-INFECTED T-CELL LINE TESTED, BUT ONLY THE 5.5-KB MRNA SPECIES IN B-LYMPHOCYTIC LINES INFECTED WITH THE DNA-VIRUS, EPSTEIN-BARR. CHANGES IN THE SIZE OF PDGFR-B MRNA IN LYMPHOCYTES BEFORE AND AFTER RETROVIRUS INFECTION WILL BE MONITORED, AND THE PDGFR-B PROTEIN WILL BE IDENTIFIED AND SUBCELLULARLY LOCALIZED. EXPRESSION OF PDGFR-B MRNAS WILL BE DETECTED BY NORTHERN HYBRIDIZATION ANALYSIS USING A SPECIFIC PDGFR-B CDNA PROBE. THE PRESENCE AND MOLECULAR SIZE OF PDGFR-B PROTEIN IN INFECTED CELLS WILL BE DETECTED BY INDIRECT IMMUNOFLUORESCENCE AND RADIOIMMUNOPRECIPITATION. THE RESULTS WILL INDICATE WHETHER HUMAN LYMPHOCYTE TRANSFORMATION BY RETROVIRUSES CORRELATES WITH THE EXPRESSION OF ABERRANT PDGRF-B MRNAS OF DIFFERENT SIZES AND CONSEQUENTLY DIFFERENT PDGFR-B PROTEINS.