In Vitro Profiling of the Antiviral Peptide TAT-I24.

Area of Science:

• Virology
• Medicinal Chemistry
• Biochemistry

Background:

• The synthetic peptide TAT-I24 demonstrates antiviral properties against various double-stranded DNA viruses.
• Cysteine residues in TAT-I24 present a challenge for peptide stability and development.
• Further characterization is needed to optimize TAT-I24 for therapeutic applications.

Purpose of the Study:

• To characterize and improve the in vitro properties of the antiviral peptide TAT-I24.
• To evaluate the impact of cysteine modifications on TAT-I24's antiviral activity and biochemical characteristics.
• To assess the safety profile of TAT-I24 and its variants regarding blood cell interactions.

Main Methods:

• Generation and testing of TAT-I24 peptide variants with cysteine replacements or deletions.
• In vitro antiviral activity assays against double-stranded DNA viruses.
• Biochemical analyses to assess peptide properties.
• Hemolysis assays using red blood cells (RBCs).
• Cytokine release assays (interleukin-6 and tumor necrosis factor-α) in human peripheral blood mononuclear cells (PBMCs).

Main Results:

• Cysteine replacements, such as deleting cysteine 14, did not diminish antiviral activity and improved biochemical properties.
• Cyclization of cysteines 14 and 20 significantly reduced antiviral efficacy.
• TAT-I24 and its variants showed no significant hemolysis or modulation of cytokine release at concentrations below 20 µM.
• The peptide and its variants appear safe for blood cells.

Conclusions:

• TAT-I24 is a promising antiviral peptide with potential for modification.
• Optimizing cysteine residues can enhance peptide properties without compromising antiviral efficacy or safety.
• TAT-I24 variants exhibit a favorable safety profile, indicating low risk of adverse effects on blood cells.