Activation imaged with quantitative fluorescence staining
A recent study conducted at Indiana University’s Department of Chemistry explored the potential use of Janus particles in T cell activation. Activation of T cells is a key step in the immune response. Various classes of T cells catalyze the destruction of viruses, pathogens and even cancerous cells. Thus, T cell activation holds great promise in disease treatment by enabling the body’s own disease-fighting mechanisms.
Adoptive T cell therapy to treat disease was previously achieved in vivo using antigen-presenting cells (APCs). However, this technique is costly, time-consuming and often irreproducible. Janus particles provide a more cost-effective and controllable solution.
Janus particles are a unique type of nanoparticle that have two or more distinct chemical properties. Researchers saw this dual nature as a valuable feature for T cell activation – a process that involves a specific spatial arrangement of ligands on the T cell surface. Receptors on the membrane of the T cell are arranged in a bull’s-eye pattern. The activating cell must bind to these receptors to elicit T cell activation.
Researchers used microcontact printing to produce two configurations of the Janus particle, which contained both fibronectin and anti-CD3. These particles were then incubated with T cells. T cell activation was measured by quantifying fluorescence staining of the influx of calcium ion associated with activation. T cells incubated with Janus particles possessing greater levels of anti-CD3 exhibited more calcium influx, indicating greater activation intensity.
Although further research is necessary to ensure correct configuration of the Janus particles upon contact with T cells, recent developments suggest that future techniques may allow mechanical manipulation of particles with optical tweezers.