Correlative imaging using super-resolution fluorescence microscopy and soft X-ray tomography at cryogenic temperatures provides a new way to assess virosome solutions for vaccine development.
Chidinma Adanna OkoloArchana JadhavPatrick PhillipsMaud DumouxAmanda A McMurrayVishwas D JoshiClaire PizzeyMaria HarkiolakiPublished in: Journal of microscopy (2021)
Active virosomes (AVs) are derivatives of viruses, broadly similar to 'parent' pathogens, with an outer envelope that contains a bespoke genome coding for four to five viral proteins capable of eliciting an antigenic response. AVs are essentially novel vaccine formulations that present on their surface selected viral proteins as antigens. Once administered, they elicit an initial 'anti-viral' immune response. AVs are also internalised by host cells where their cargo viral genes are used to express viral antigen(s) intracellularly. These can then be transported to the host cell surface resulting in a second wave of antigen exposure and a more potent immuno-stimulation. A new 3D correlative microscopy approach is used here to provide a robust analytical method for characterisation of Zika- and Chikungunya-derivatised AV populations including vesicle size distribution and variations in antigen loading. Manufactured batches were compared to assess the extent and nature of batch-to-batch variations. We also show preliminary results that verify antigen expression on the surface of host cells. We present here a reliable and efficient high-resolution 3D imaging regime that allows the evaluation of the microstructure and biochemistry of novel vaccine formulations such as AVs.
Keyphrases
- high resolution
- sars cov
- induced apoptosis
- immune response
- single molecule
- zika virus
- cell cycle arrest
- mass spectrometry
- cell surface
- high speed
- electron microscopy
- poor prognosis
- white matter
- aedes aegypti
- magnetic resonance imaging
- cell death
- oxidative stress
- optical coherence tomography
- long non coding rna
- anaerobic digestion
- gram negative