Immunological Studies by HHMI Early Career Scientist

Associate Professor of Immunobiology Susan Kaech is now a Howard Hughes Medical Institute (HHMI) Early Career Scientist. The accolade, which was awarded in spring 2009 to only fifty “junior” scientists nationwide, includes a six-year, 1.5 million dollar research grant.

Kaech, an expert on T cell differentiation, plans to use the additional funding to pursue her research on how memory T cells acquire certain features common to stem cells, mainly longevity, self-renewal, and potential for proliferation. “My laboratory is interested in cataloging all of the signals, pathways, and molecules involved in the differentiation of memory T cells,” she said.

T cells play a crucial role in the adaptive immune system, responsible for recognizing fragments of pathogens and for destroying infected cells. As Kaech explains, “Following infection or vaccina­tion, T cells expand exponentially and differentiate into effector T cells in order to control infection and coordinate the multiple effector arms of the immune system.”

Usually, these cells are short-lived in order to maintain homeostasis, but certain T cells become long-lived and remain within the host’s immune system long after infection. This acquisition of immunological memory allows the immune system to prevent subsequent infections from the same pathogen.

Currently, Kaech is employing mouse models to understand how longevity is conferred. She is infecting mice with lymphocytic choriomeningitis virus (LCMV) and isolating their T cells for cell biology studies. “Mice have a robust immune system; they also generate a lot of T cells for us to examine,” said Kaech.

Using this technology, Kaech has made several significant breakthroughs. Among her discoveries was the identification of precursor cells that give rise to the long-lived memory CD8 T cells after infection – a finding that will help researchers elucidate how memory T cells develop during infections and vaccinations.

Kaech anticipates that within ten years enough information will be known to design a new gen­eration of drugs and vaccines. “Immunological memory has potential to be applied in therapeutics. Understanding, how these cells acquire features of longevity can aid in vaccine design for tumors and chronic infections.”