Virus-like particle

Virus-like particles resemble viruses, but are non-infectious because they contain no viral genetic material. The expression of viral structural proteins, such as Envelope or Capsid, can result in the self-assembly of virus like particles (VLPs). VLPs derived from the Hepatitis B virus and composed of the small HBV derived surface antigen (HBsAg) were described in 1968 from patient sera. VLPs have been produced from components of a wide variety of virus families including Parvoviridae (e.g. adeno-associated virus), Retroviridae (e.g. HIV), Flaviviridae (e.g. Hepatitis C virus) and bacteriophages (e.g. Qβ, AP205). VLPs can be produced in multiple cell culture systems including bacteria, mammalian cell lines, insect cell lines, yeast and plant cells.

VLPs are used in studies to identify viral protein components.

VLPs are a candidate delivery system for genes or other therapeutics. These drug delivery agents have been shown to effectively target cancer cells in vitro. It is hypothesized that VLPs may accumulate in tumor sites due to the enhanced permeability and retention effect, which could be useful for drug delivery or tumor imaging

VLPs are useful as vaccines. VLPs contain repetitive, high density displays of viral surface proteins that present conformational viral epitopes that can elicit strong T cell and B cell immune responses. Since VLPs cannot replicate, they provide a safer alternative to attenuated viruses. VLPs were used to develop FDA-approved vaccines for Hepatitis B and human papillomavirus. More recently, VLPs were used to develop a pre-clinical vaccine against chikungunya virus.

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