NEUROTROPIN INHIBITS HUMAN-IMMUNODEFICIENCY-VIRUS (HIV)-INDUCED SYNCYTIUM FORMATION

Development of effective therapeutic programmes that are useful during the early phase of HIV-1 (human immunodeficiency virus type-1) infect ion is a critical goal. Indeed, many patients remain asymptomatic for years before the development of clinical manifestations. Neurotropin, a well-characterized immune modulator, is known to inhibit HIV product ion in vitro (1). To further understand the relationship between effec ts of Neurotropin and cytopathic effects of HIV-1, the authors investi gated Neurotropin-responsive molecules expressed on the HIV-infected T -cell line (MT-2) and the effect of Neurotropin on HIV-induced syncyti um formation. The protein extracts from HIV-infected MT-2 cells treate d with or without Neurotropin were analysed by two-dimensional polyacr ylamide gel electrophoresis (2-D PAGE). Four protein molecules, design ated as HMP (HIV-induced MT-2 Protein) 1, 2, 3 and 4 which were not HI V components but cellular products were derived from infected MT-2 cel ls. The isoelectric point of HMP-1 changed from 5.8 to 5.6 upon Neurot ropin treatment. The isoelectric point of HMP-2, HMP-3 and HMP-4 did n ot change after Neurotropin treatment. When MT-2 cells were pretreated with 10 to 100 mu g/ml of Neurotropin, HIV-induced syncytium formatio n was inhibited by 70% as compared to those of untreated MT-2 cells. T hese results suggest that HMP-1 inhibited syncytium formation by HIV-1 infected MT-2 cells may be a target of the bioactive effect of Neurot ropin.