MIMP is a new thymomimetic
purine under development for immunorestorative
therapy. Lymphocytes were obtained from eight patients with acquired immunodeficiency disease (
AIDS), eight with symptomatic pre-
AIDS (
ARC), and 22 normal controls and were stimulated in vitro with
phytohemagglutinin (PHA).
AIDS patients (mean CD4 counts of 40) showed PHA responses less than 10% of control while
ARC patients (mean CD4 counts of 544) showed responses approximately 50% of the control responses.
MIMP (0.1, 1, 10 and 100 micrograms/ml) progressively augmented the PHA responses in all these groups. The augmentation of the responses of the leukocytes of
AIDS patients while statistically significant was minimal. The augmentation of the responses of
ARC patients was significant and their maximal responses approached control levels. The effect of 1 micrograms/ml
MIMP was comparable with that observed with
indomethacin (10(-6) M) and
interleukin-2 (
IL2 - 4 units/ml) and was additive with each of these stimulants. In a parallel manner,
MIMP restored the suppression of control lymphocytes induced by the immunosuppressive 17
amino acid fragment of the P41
peptide of HIV. In vivo experiments showed that
MIMP significantly delayed death in a murine FLV
AIDS model at a dose of 1 mg/kg by the oral or parenteral route.
MIMP is under preclinical development for early HIV disease to forestall progression to
AIDS by attenuating virus-induced immunosuppression.