MINNEAPOLIS/ST. PAUL (October 27, 2013) – New research from the Masonic Cancer Center, University of Minnesota, and the University of Minnesota Center for Immunology has identified key proteins that influence immune response strategies, a finding that could influence new vaccination approaches.
The study, published in the latest edition of Nature Immunology, looked closely at the KLF2 and S1P1 genes, and how their expression impacted the immune strategy of a cell.
The immune system has two main strategies to empower white blood cells, or lymphocytes, to resist infections of the body.
The first strategy, called recirculation, is a process where white blood cells are carried around in circulating blood, allowing rapid access to organs once an immune response has begun.
The second major strategy allows lymphocytes to migrate into tissues and remain there long-term, creating a kind of rapid response team to any infectious organism that enters the body. These cells are called resident memory T-cells or Trm, and they play a dominant role in initiating immune responses that control infections.
"A key question we had was how lymphocytes make the choice to be a recirculator or a resident," said Stephen Jameson, Ph.D., a professor in the Center for Immunology and Department of Laboratory Medicine and Pathology in the University of Minnesota Medical School. "We already knew the protein KLF2 regulates the expression of genes. One of those genes, called S1P1, allows lymphocytes to leave tissues and begin recirculating."
Intrigued by the impact of KLF2 and S1P1 on lymphocytes' ability to move out of tissues, Jameson and colleagues wanted to compare resident and recirculating cells and the KLF2 and S1P1 levels. They found that resident T-cells had lost expression of the KLF2 and S1P1 genes.
The next step was finding what controlled the expression of KLF1 and S1P1. Jameson's team was able to pinpoint cytokines as playing a major role in this cell decision-making process.
"Cytokines are soluble proteins that act similar to hormones for the immune system," said Jameson. "We found the cytokines can instruct cells to become resident memory cells, thereby may be useful for bolstering local immunity."
Though further research is needed to define the biochemical signals dictating how recirculation versus residency is chosen, learning more about these key signals instructing T-cells to determine their strategic immunity role could significantly improve vaccination approaches. Researchers may be able to use the knowledge and develop technology to focus memory T-cells to form a barrier to infections.
This project was supported by funding from an NIH MERIT award to Jameson (R37 AI38903) and an NIH training grant for Cara Skon (T32 AI07313), as well as other NIH grants to contributing authors (R37 AI39560 and T90 DE022732).
The Center for Immunology is a interdisciplinary unit at the University of Minnesota devoted to advancing the field of Immunology and educating future Immunologists. Learn more at http://www.immunology.umn.edu.
Masonic Cancer Center, University of Minnesota is part of the University's Academic Health Center. It is designated by the National Cancer Institute as a Comprehensive Cancer Center. For more information about the Masonic Cancer Center, visit http://www.cancer.umn.edu or call 612-624-2620. The University of Minnesota Medical School, with its two campuses in the Twin Cities and Duluth, is a leading educator of the next generation of physicians. Our graduates and the school's 3,800 faculty physicians and scientists advance patient care, discover biomedical research breakthroughs with more than $180 million in sponsored research annually, and enhance health through world-class patient care for the state of Minnesota and beyond. Visit http://www.med.umn.edu to learn more.
Journal
Nature Immunology