A host cell is a living cell that is infected or invaded by an external organism or genetic material, such as a virus, bacteria, plasmid, or other foreign DNA. The host cell provides the necessary machinery and resources for the invading organism or genetic material to replicate, express its genes, and propagate within the host organism. Host cells can be derived from a variety of organisms, including bacteria, plants, animals, and humans.
In the context of molecular biology and biotechnology, host cells are often used as platforms for the production of recombinant proteins, vaccines, or gene therapies. Researchers can introduce foreign DNA into the host cell, which then uses its own cellular machinery to produce the desired proteins or other molecules encoded by the introduced genetic material. This process is called genetic engineering or transfection.
In the case of viral infections, the host cell is hijacked by the virus to replicate its genetic material and produce new viral particles. The viral life cycle can cause various outcomes for the host cell, including cell lysis (destruction), the formation of syncytia (multinucleated cells formed by the fusion of multiple cells), or the incorporation of viral DNA into the host cell’s genome, which can lead to latent infections or even oncogenic transformation.
Host cells play a crucial role in understanding cellular processes, interactions between pathogens and host organisms, and the development of novel therapies and vaccines. The choice of host cell for a particular study or application depends on several factors, including the ease of genetic manipulation, the ability to produce the desired molecule or effect, and the compatibility with the target organism or system.