Matthew L. Nicotra, PhD

We study allorecognition, which is the ability to distinguish between self tissues and those belonging to members of the same species via cell-cell contact. Allorecognition is typically thought of as describing how a transplant recipient’s immune system recognizes a donated organ and subsequently mounts an immune response against it.  However, colonial marine invertebrates—animals like corals, marine sponges, and some sea squirts—are also capable of allorecognition.  These animals have genetically-based allorecognition systems that allow them to distinguish between their own tissues and those of unrelated members of their own species based on cell-cell contact.  They generally reject foreign tissue but accept and fuse to their own tissues.

Our lab seeks to understand the molecular basis, evolutionary history, and medical relevance of invertebrate allorecognition using the colonial hydroid, Hydractinia symbiolongicarpus, as a model system. A central question we wish to answer is whether invertebrate allorecognition systems share an evolutionary history with elements of the human immune system and, if so, whether this leads to new or previously unappreciated pathways in transplant rejection.
Two nascent projects using Hydractinia as a model system focus on mechanisms that generate genetic diversity (specifically those promoting recombination within gene families) and stem cell biology (specifically an example of natural cellular reprogramming).

Finally, in addition to our invertebrate work, my group also collaborates with the Lakkis lab on a project to determine how the mammalian innate immune system is able to detect and responds to alloantigens.