Naturally Derived Anti-HIV Polysaccharide Peptide (PSP) Triggers a Toll-Like Receptor 4-Dependent Antiviral Immune Response

Figure 1

Polysaccharide peptide (PSP) activates human cells without significant cytotoxicity. HIV-1-infected and uninfected THP1 cells and freshly isolated human peripheral blood mononuclear cells (PBMC) were exposed twice (treated at day 0 and day 3) with various PSP concentrations (0–1000 μg/ml) over a six-day period, with 0 μg/ml as negative control. (a) Half maximal effective concentration (EC50) was determined by measuring secreted embryonic alkaline phosphatase (SEAP) activity in the culture supernatant using QUANTI-Blue assay after 6 days of treatment. Reduction of alamarBlue was used to determine the optimal time course between 3 and 6 days of treatments in either (b) HIV-1-negative and (c) HIV-1-positive THP1 cells. Cell viability was confirmed by tetrazolium MTT assay after a six-day period in (d) HIV−/HIV+ THP1 cells and (e) HIV−/HIV+ human PBMCs. Statistical significance was determined using one-way ANOVA, (, , and ).

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