A COLORIMETRIC REVERSE-TRANSCRIPTASE ASSAY OPTIMIZED FOR MOLONEY MURINE LEUKEMIA-VIRUS, AND ITS USE FOR CHARACTERIZATION OF REVERSE TRANSCRIPTASES OF UNKNOWN IDENTITY

A non-radioactive reverse transcriptase (RT) assay, reported as useful for lentivirus RTs, was optimized for the measurement of Moloney muri ne leukemia virus (MMuLV) RT. The optimized assay could detect 0.3 mu U of MMuLV RT. The specificities of the MMuLV and lenti RT assays were demonstrated using the RTs of human immunodeficiency virus type 1, si mian immunodeficiency virus, feline immunodeficiency virus (FIV). visn a virus, human T-cell lymphotropic virus type 1, MMuLV and feline leuk emia virus (FeLV). An RT activity blocking antibody (RTb-ab) assay was standardized for Mn2+ dependent MuLV-related RTs. The assay was used to demonstrate the distinct antigenic properties of RTs from mammalian MuLV-related retroviruses and lentiviruses. Cross-reactivity between MMuLV RTb-ab and FeLV RT but not between MMuLV RTb-ab and e.g. FIV RT was demonstrated. An RT activity found in the murine myeloma cell line SP2/0 was found to have similar assay preferences as MMuLV RT, and th e MMuLV-RT hyperimmune sera reacted strongly against this RT, indicati ng the RT to be of MuLV-related etiology. The use of the RT and RTb-ab assays for detection and characterization of RTs of known or unknown identity is discussed. (C) 1998 Elsevier Science B.V. All rights reser ved.