Background: Chronic liver disease is often associated with the infection by hepatitis C
virus (HCV), which is an enveloped RNA virus belonging to the Flaviviridae family. Many studies
found that milk proteins, such as lactoferrin, might have profound antiviral activity against HCV.
Various secretory fluids ranging from milk, to tears, saliva, and nasal secretion, and to bile and pancreatic
juice, as well as neutrophils, mucosal surfaces, and blood contain a widely spread multifunctional
glycoprotein, lactoferrin (Lf), structure of which can be depicted as two homologous domains
connected by the short spacer peptide.
Objective: This study aimed to understand the effectiveness of the synthetic peptides cLfsp, bLfsp,
hLfsp1, and hLfsp2 corresponding to the spacer peptides of camel, bovine, and human Lfs, respectively,
against HCV in in vitro settings.
Method: We used RT-nested PCR to evaluate the antiviral activity of the synthesized spacer peptides
against HCV infectivity in PBMC and HepG2 cells looking at their neutralization, protection, and
intracellular treatment potentials.
Results and Conclusion: We show that direct interaction of hLfsp1, hLfsp2, and bLfsp with viral
particles is able to neutralize the HCV entry into HepG2 cells (with hLfsp2 being more potent neutralizer
than hLfsp1 and bLfsp), whereas cLfsp does not show any neutralizing potential. Therefore,
our analysis revealed that different spacer peptides are characterized by different antiviral potentials
and use different mechanisms for antiviral protection.