3-Hydroxyphthalic Anhydride- Modified Rabbit Anti-PAP IgG as a Potential Bifunctional HIV-1 Entry Inhibitor

Abstract

Several studies have reported that amyloid fibrils in human semen formed from a naturally occurring peptide fragment of prostatic acidic phosphatase (PAP248-286), known as semen-derived enhancer of viral infection (SEVI), could dramatically enhance human immunodeficiency virus type 1 (HIV-1) infection. Accordingly, SEVI might serve as a novel target for new antiviral drugs or microbicide candidates for the prevention of sexually transmitted HIV. Theoretically, a special anti-PAP or anti-SEVI antibody could reduce the enhancement of viral infection by blocking the binding of HIV and SEVI fibrils. Here, 3-hydroxyphthalic anhydride modified anti-PAP248-286 antibody, named HP-API, exhibited broad-spectrum and highly effective anti-HIV-1 activities on different subtypes and tropism. By using time-of-addition, cell–cell fusion and a single-cycle HIV-1 infection assays, we demonstrated that HP-API is an HIV-1 entry/fusion inhibitor. Mechanism studies suggest that HP-API inhibited HIV-1 entry/fusion by targeting both HIV-1 gp120 envelop and CD4 receptor on the host cell specifically. It is noteworthy that HP-API abrogated the formation of SEVI fibrils and partially interfered with SEVI-mediated enhancement of HIV-1 infection. Based on these findings, HP-API could be considered a bifunctional HIV-1 entry/fusion inhibitor with high potential.

Fejerlectin, a Lectin-like Peptide from the Skin of Fejervarya limnocharis, Inhibits HIV-1 Entry by Targeting Gp41

“…To investigate the in vitro antiviral activity of fejerlectin at different time points after virus infection, the time-of-addition assay was carried out as previously reported . In short, 50 μL of HIV-1 NL4‑3 , HIV-1 SF162 , and HIV-1 81A and NL4‑3 at 100 TCID 50 were used to infect 100 μL of 5 × 10 5 /mL TZM-bl cells for 0, 0.5, 1, 2, 4, 6, 8, and 24 h at 37 °C before adding 50 μL of fejerlectin (25 μM), AZT (45 nM), maraviroc (24 nM), or AMD3100 (50 nM).…”

“…To investigate the in vitro antiviral activity of fejerlectin at different time points after virus infection, the time-of-addition assay was carried out as previously reported. 54 In short, 50 μL of HIV-1 NL4-3 , HIV-1 SF162 , and HIV-1 81A and NL4-3 at 100 TCID 50 were used to infect 100 μL of 5 × 10 5 /mL TZM-bl cells for 0, 0.5, 1, 2, 4, 6, 8, and 24 h at 37 °C before adding 50 μL of fejerlectin (25 μM), AZT (45 nM), maraviroc (24 nM), or AMD3100 (50 nM). The culture supernatants were replaced with fresh medium 24 h post-infection, and the culture supernatants were collected for measuring p24 antigen levels, as described in the above anti-HIV-1 infection assay after 48 h of infection.…”

Atomistic Simulations of PAP248-286 Peptide Oligomerization

“…SEVI binds to both HIV virions and target cells, thereby increasing viral attachment, fusion, and infection. Due to its stable structure and high concentration in semen, SEVI is an attractive drug target for preventing HIV infection [21][22][23].…”

Tolcapone Potently Inhibits Seminal Amyloid Fibrils Formation and Blocks Entry of Ebola Pseudoviruses

“…During our review of the amyloid inhibitors in the literature in our previous study (Lump et al, 2015;Xun et al, 2015;Ren et al, 2018;Zhang et al, 2018;Li et al, 2019;Tan et al, 2019), we noticed that tolcapone, an active catechol-O-methyltransferase (COMT) inhibitor clinically used as an adjunct to levodopa/carbidopa for Parkinson's disease (Olanow and Watkins, 2007;Müller, 2015), possessed inhibitory activity against transthyretin (TTR) amyloidosis, which is a plasma homotetrameric protein associated with fatal systemic amyloidoses. Tolcapone was also shown to be effective in treating amyloid transthyretin (ATTR) amyloidosis in vivo (Gamez et al, 2019).…”