自放大RNA:用于疫苗开发的多功能平台的优点和挑战

A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material for adaptive...

During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA.  Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for...

Microorganisms play a fundamental role in vaccine development, gene therapy, and therapeutic production. Their biological properties are harnessed to advance medicine and public health. Beyond immunization, microorganisms contribute to gut health, antibiotic synthesis, and genetic disease treatment.Live Attenuated and Inactivated VaccinesLive attenuated vaccines, such as the measles, mumps, and rubella (MMR) vaccine, utilize weakened forms of pathogens to closely resemble natural infections.

RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...

Vaccine production involves a sequence of upstream and downstream processes to generate a safe and effective immunological product. It begins with cultivating microorganisms, such as viruses or bacteria, to obtain antigenic material. For viral vaccines, mammalian host cells are grown in bioreactors and subsequently infected with the target virus. The virus replicates within the host cells, which are lysed to release viral particles. This lysate is then clarified through filtration or...

Vaccines are among the most effective tools in preventive medicine, designed to prepare the immune system to recognize and combat infectious agents. By introducing antigens—substances that the immune system identifies as foreign—vaccines stimulate an adaptive immune response that leads to immunological memory. This immunological memory enables the body to mount a faster and more effective response upon future exposures to the actual pathogen.Vaccines can be categorized based on the type of...