Sulfation of the immunomodulating polysaccharide lentinan: A novel strategy for antivirals to human immunodeficiency virus (HIV)

Abstract

It has been clearly established that human immunodeficiency virus (HIV) is a causative agent of the acquired immunodeficiency syndrome (AIDS). The virus preferentially infects and kills CD-4-positive (helper/inducer) T lymphocytes resulting in severe T4 lymphopenia as well as indirect suppression of multiple immune functions which are dependent on induction of T4 cells (1–2). Since AIDS is a disease in which the HIV destroys the T4 cells slowly but continuously, it is apparent that any attempt to treat AIDS must include anti-HIV therapy. Furthermore, attempts must be made to reconstitute immunologic disfunction caused by the virus. Recently, it has been reported that a sea algal extract (SAE) from Schizymenia pacifica inhibits viral adsorption to the cells and reverse transcriptase (RT) of HIV without interfering with cell growth in vitro (3–4). The active substance in the SAE was found to be a member of the carrageenan family, a sulfated polysaccharide. It has also been shown that a number of sulfated compounds such as Evans blue and suramin were anti-HIV substances in vitro (5). The following represents a continuation of this team's studies on the chemical modification of compounds for inhibitors against HIV. In this study, the immunomodulator lentinan and other nonsulfated polysaccharides were sulfated and their anti-HIV effects were studied in vitro .