N6-(DELTA2-ISOPENTENYL)ADENOSINE-EFFECTS UPON NUCLEIC ACID SYNTHESIS IN LYMPHOCYTES IN VITRO AND DEVELOPMENT OF IMMUNOLOGIC HYPERSENSITIVITY IN VIVO

The nucleoside, N6-(Δ2-isopentenyl)adenosine (iPA), shown to be an integral constituent of certain transfer RNA's, has been found to inhibit the incorporation of uridine into RNA and thymidine into DNA. This assay in vitro, which uses phytohemagglutinin-transformed rat spleen cells, may reflect a measurement of immunosuppression. Although not as pronounced, inhibition has also been demonstrated in LM cells as well. Evidence for an immunosuppressant property of iPA in vivo has been acquired, by using an immediate cutaneous hypersensitivity assay in rats. Reference experiments were also conducted in parallel, testing actinomycin D and prednisolone, to ascertain their effects as immune-response depressants using both techniques described. © 1969.