Developing Novel Techniques for Studying Viral Surfaces and Identifying New Therapeutic Targets
Viruses are typically drawn as in Fig 1A, with the viral spike proteins shown as the the only visible proteins on virus surfaces. Thus, these spike proteins are the typical targets of vaccines and antivirals. Our lab has extensive expertise in studying virion surfaces, with a unique emphasis on identifying human proteins on virus surfaces. Our research highlights that the textbook schematic of viral particles is not what viruses look like in the real-world. In reality, when viruses replicate in human cells, they also hijack human proteins, covering their surface with a variety of cellular proteins derived from the cells which they infect. Importantly, the incorporation of human proteins onto virus surfaces imparts new biological features to the virus. For example, our previous research has identified two human proteins, integrin α4β7 and PSGL-1, that can alter virus trafficking and infectivity, respectively, when incorporated onto the HIV surface (PMID:28763793 and PMID: 35597982). Impressively, when we analyze clinical samples from HIV-infected patients, we consistently detect viruses with these human proteins on their surfaces, indicating that real-word viruses do indeed look like Fig 1B.
Ongoing research in our lab is geared towards establishing new protocols for analyzing virus particles with an emerging technique called flow virometry. Flow virometry uses antibodies to identify unique proteins on viruses. Importantly, very few labs are versed in this technique worldwide, and few have access to the cutting-edge instruments required for this technique. Our lab is equipped with the CytoFlex S Cytometer (Beckman Coulter) for dedicated use within our own laboratory, enabling flow virometry at our fingertips! We have also established the instrument parameters to perform quantitative flow virometry, enabling us to identify the absolute number of protein molecules per individual virus particle (PMID:33198254). This quantitation enriches our understanding of the virus phenotype, and informs us on protein abundance and the related feasibility for targeting these proteins with therapeutics.
Novel Cytokine Expression Patterns
It has been well established that cytokines have extraordinary potential as ‘immunological multi-taskers’. These small molecular weight proteins can be expressed via a variety of stimuli, in a multitude of cell types throughout the body, and can elicit a broad range of responses. Key features of cytokines, such as glycosylation and positioning of charged domains, can drastically influence biological functions, protein stability, protein-protein interactions (oligomerization), and receptor engagement.
Interestingly, some cytokines can even be stored at high concentrations, preformed inside producer cells, awaiting rapid release without requiring de novo synthesis, resulting in high-speed immune responses. While much work is centered on downstream functions of cytokines, we seek to understand earlier events in the expression, secretion, and interplay among these proteins, in an effort to establish how cytokines are regulated in a normal-functioning immune system, before disease disrupts the equilibrium.