HIGH SPATIO-TEMPORAL RESOLUTION OF MULTIMODAL

Innovative themes of utilizing highly coherent or structured illuminations will be the focus of bioimaging in the characterization of intracellular networking mediated by the replication cycles of viruses —the architectural and the cellular membrane aspect of cell compartments. By permitting the visualization of biomolecules and viruses in a native hydrated state, cryo-microscopy and electron tomography provide us comprehensive tools in linking the molecular mechanisms of viral genome packaging with observations between the detailed structures of near-atomic resolution and the architectures of cellular membrane compartments regarding the dynamic function of the virus assemblies. Imaging of an infected cell can now be performed with correlative labelling of nanoscale immunological, genetic and/or chemical probes, in aiming to follow the packaging of influenza virus genome segments into a budding virion throughout the nuclear export and cytoplasm transport. The compilation and integration of methodology provide timeresolved observations on the reactivity of structures from near-atomic resolution to various molecular and cellular levels of descriptors. By permitting the visualization of biomolecules in a native hydrated state, cryo-microscopy and electron tomography offer an explorative tool to compile observations of crystallography and of biophonics techniques in lightening the architectures of membrane compartments and molecular machines relevant to the dynamic cell function involving the macromolecular assemblies (e.g., Cheng and Hammar 2004, ISBN 981-238-614-9; Cheng and Miyamura 2007, ISBN 981-270-405-1). Another example is to combine coherent anti-stokes Raman scattering and multi-photon excited fluorescence microscopy in continuously imaging the dynamic information of the interaction between viruses and the host cells. This high temporal resolution can thus be further followed by cryo electron microscopy with detailed spatial configuration throughout the virus infection process — the translocation of the virus into various cellular compartments, the replication, and the release process of new virus particles from the host cell. Teamwork research and creative integrations of the complementary imaging methods will be essential in following the multiple scales and resolutions of related spatial frameworks in revealing functional integrity that persists throughout the transient macromolecular interactions (e.g., Wu et al., 2007. J Biol Chem, 282, 6752; Xing et al., 2004 J Biol Chem, 279, 11632; http://www-ucdmag.ucdavis.edu/su06).
Transmissible spongiform encephalopathies (TSE) are fatal neurodegenerative diseases of humans and animals. The underlying infectious agent, the prion, accumulates not only in the central nervous system (CNS) but also in secondary lymphoid organs. I will revisit the role of the immune system in peripheral prion pathogenesis, while focusing on the mechanisms by which extraneural and extralymphatic prion infectivity develops. Interestingly, the same pro-inflammatory cytokines and homeostatic chemokines that are involved in lymphoid neogenesis and compartmentalization of immune cells appear to represent the crucial molecular switches responsible for the establishment of extraneural prion reservoirs.