Pompano Lab

We want to see the immune system in action...

  ...right down it its chemistry.

We ask questions such as:

• How do cells of the immune system respond to chemical stimulation? How do the location and the timing of stimulation affect the response?

• How do local inflammatory chemical signals drive the chronic inflammation seen in autoimmune disease?

• What is the best way to build a model of the immune system to replicate immunity outside the body?

With these questions in mind, we build the microfluidic devices, chemical assays, and computational models that are needed to answer them.  Ultimately, our work will create new tools to understand how the immune system is organized.  We and others will use these tools to make progress towards therapies for diseases such as multiple sclerosis, Alzheimer's disease, and solid tumors.

We have several lines of ongoing research:

1.  Develop and utilize microfluidic platforms for ex vivo analyses of live tissue.  For example, we developed the first microfluidic device capable of mimicking the localized stimulation that occurs in lymph nodes in vivo, by delivering localized chemical stimuli through a port beneath a sample of living lymph node tissue (see Publications).  We have used this device to measure diffusion of active proteins through live lymph node tissue for the first time (featured in C&E News), and to build multi-organ models of immunity. We are now creating other innovative device designs to further control the environment around live tissue slices.

2.  Design new biochemical assays to visualize the chemistry in living tissue.  We are happy to share our method for “live immunostaining” of cells and structures in live tissue explants. We have assays in the works to detect secreted proteins, oxygen consumption, and recently published a method to map out glucose consumption in living tissue. 

3.  To enable projects 1 and 2, we first had to verify that live slices of lymph node tissue were useful as a model of immunity.  We spent several years demonstrating the strengths and best uses of this unique tissue culture model, and are now applying it to learn about the response to vaccination, tumor immunity, and other systems. We are happy to spread this useful system to other laboratories, and indeed have already done so. Ask us for more information if interested.

4. Develop the first spatially organized in vitro model of a human lymph node, in a unique organ-on-chip model of this organ. This U01-funded project integrates biomaterials design and micropatterned 3D cell culture, microfluidic environmental control, and deep expertise from our immunology collaborators. In this effort, we are part of the NIH TissueChip Consortium and aspire to eventually integrate the lymph node with other organ-on-chip models, for full multi-organ immunity.

Applications:  Chronic Inflammatory Disease and Tumor Immunology

Currently, attention in the lab is focused on developing tools to understand the mechanisms of chronic inflammation in the context of autoimmune disease and cancer immunology.  Chronic inflammation arises when the immune system gets caught in an ongoing state of activation towards a target that cannot be cleared -- for example, against proteins in the joints (rheumatoid arthritis), in the gut (inflammatory bowel disorder), in the myelin that protects neurons in the brain (multiple sclerosis), or in a solid tumor.  This state is poorly understood, in part because it is difficult to reproduce it in vitro, and in part because it is driven by a complex set of chemical signals -- cytokines and chemokines -- that have been difficult to quantify over time and with sufficient spatial resolution.

 Our core toolbox includes:

1. Microfluidics and organs-on-chip

At their simplest, microfluidic devices are miniature plumbing systems built from channels that are tens to hundreds of micrometers (microns) wide.  Because most cells from humans and other mammals are approximately 5 - 20 microns in diameter, microfluidic channels are ideally sized to manipulate and stimulate samples of cells and tissues.

We build microfluidic devices from glass, soft or hard polymers (plastics), or biomaterials such as agarose and gelatin.  In all cases, the chemistry on the surface of the device can be modified as needed. For example, surfaces can be made hydrophilic or hydrophobic, cell-adhesive, or protein-repellent.  The device can also be used to deliver controlled gradients of signalling molecules.

In this area, we have a major effort in the field of organs-on-chip. We are developing novel methods to replicate immunity outside of the body.

2. Bioanalytical chemistry

Cells in tissues communicate with one another by releasing proteins and small molecules that travel to their neighbor (or farther!) to carry a message.  If we as scientists want to "listen in," most chemical approaches measure the molecules after they have been collected in a fluid -- cell culture media, serum, urine, etc.  This approach relinquishes all information about where each molecule came from.  In our lab, we specialize in detecting proteins and other biological signals at their source, in living tissue. 

3. Live fluorescence imaging

Seeing immunity in space and time means imaging it while it happens. We make extensive use of various types of microscopy at both the tissue scale and cellular scale to observe the location and behavior of cells in our tissues.

4. Biomaterials and 3D cell culture

For bottom-up models of the lymph node, we start by suspending cells in a 3D culture, using biomaterials as a matrix or scaffold. In collaboration with colleagues at UVA and Virginia Tech, we have begun exploring how immune function is best modeled in these materials.