Cottrell Scholar Awards - 2015
Remodeling Bacterial Cell Walls and Biochemistry Laboratory Curriculum
“I am passionate about bacterial cell walls,” confesses Catherine L. Grimes, University of Delaware assistant professor of chemistry and biochemistry.
But her passion cuts both ways: As a graduate student Grimes designed and studied antibiotics to destroy this bacterial amour.
With Cottrell Scholar funding she is enlarging the scope of the battle. Using techniques from synthetic organic chemistry, molecular biology, immunology, biochemistry and microbiology, she and her colleagues are working to understand how living cells sense and respond to the cell wall of invading and commensal (symbiotic) bacteria.
Why focus only on the cell wall?
“Because it’s found in all bacteria,” Grimes explains. “It’s a mesh-like carbohydrate polymer that provides the mechanical support to prevent the cells from bursting as the osmotic pressure fluctuates. Humans don’t have this type of cell wall, which makes it an ideal structure for allowing our innate immune systems to recognize the presence of bacteria.”
She hypothesizes that four events must take place for a human cell (or the cell of any living plant or animal, for that matter) to efficiently process and sense the bacterial cell wall: (1) the bacterial cell wall must be degraded somewhat to produce molecular fragments our immune system can recognize; (2) these fragments must find their way to the proper “compartment” within our body’s immune cells; (3) the fragments must be “engaged” by a cellular receptor, and; (4) the human cell must relay the bacteria’s “molecular signal” to generate an immune response.
Grimes is attempting to learn how to manipulate the process by which a bacterium creates its cell wall. Then she hopes to intervene in the process to install molecular probes that will enable her to determine how the human immune system breaks down the bacterial cell wall to generate an immune response.
If successful, her work would undoubtedly have major implications for stopping harmful bacterial infections or diseases caused by misrecognition of commensal bacteria, such as Crohn’s disease.
Grimes is also using some of her Cottrell Scholar funding to modernize her university’s chemistry and biochemistry curricula by developing collaborative techniques from organic chemistry, biochemistry and molecular biology, and by emphasizing collaborative learning networks among a diverse group of science students.