Estudio de Penn muestra que el sistema inmune puede lastimar así como también ayudar a luchar contra el cáncerContributed by: Anonymous · Views: 1,698
Contributed by: Anonymous · September 29, 2008 @ 10:13 AM MDT · Views: 1,698
Penn Study Shows Immune System Can Hurt As Well As Help Fight Cancer
Discovery could lead to new cancer treatments with fewer side effects
Model of the C5a molecule, part of the immune complement system.
Credit: John D. Lambris, PhD, University of Pennsylvania School of Medicine.
C5a is part of the complement system, one of the body’s immune defenses against pathogens. When activated, the system’s proteins rid the body of microbes and foreign cells. Many cancer treatments are aimed at boosting the immune system to kill tumors.
“Until now, everyone thought that the complement system was there to eliminate tumor cells. We found that in some conditions, the complement system can promote tumor growth, depending on the specific tumor and the specific environment in which the tumors are developing,” says John Lambris, PhD, the Dr. Ralph and Sallie Weaver Professor of Research Medicine.
However, Penn researchers found that in a mouse model, activation of the complement system in tumor tissue leads to the generation of C5a, which recruits myeloid-derived suppressor cells (MDSC) to tumors. These MDSCs block the function of CD8+ T cells, which would normally dismantle a tumor.
Researchers also found that blocking the C5a receptor on cell surfaces impairs tumor growth at the same rate of Pa*censored*axel, a chemotherapy drug. This discovery could lead to new cancer treatments with far fewer side effects than chemotherapy, surmise the investigators.
“Researchers are trying to introduce immune therapies and anti-tumor vaccines, but most of these vaccines fail,” says Lambris. “We show in this study a possible mechanism how to overcome this problem.” Lambris and his team are conducting studies that apply the approaches outlined in this paper to five models of cancer.
In addition to Lambris, Penn co-authors are Maciej M. Markiewski, Robert A. DeAngelis, Salome K Ricklin-Lichtsteiner, Anna Koutoulaki, Fabian Benencia (now at the University of Ohio), and George Coukos, as well as Craig Gerard, Children’s Hospital, Boston. The National Institutes of Health provided funding for this research.
Courtesy: Penn Medicine