Monday, June 15, 2015

Loyola Study Shows How to Rescue the Immune System in Compromised Conditions

Results Could Lead to Novel Therapy for Cancer Patients

MAYWOOD, Ill. – In a study published in Nature Medicine, Loyola researchers report on a promising new technique that potentially could turn immune system killer T cells into more effective weapons against infections and possibly cancer.

The technique involves delivering DNA into the immune system's instructor cells. The DNA directs these cells to overproduce a specific protein that jump-starts killer T cells -- immune system cells that attack cancer cells and pathogens.

These killer cells are typically repressed in patients who have HIV or cancer, said José A. Guevara-Patino, MD, PhD, senior author of the study. Guevara is an associate professor in the Oncology Institute of Loyola University Chicago Stritch School of Medicine.

Guevara and colleagues reported their technique proved effective in jump-starting defective immune systems in immuno-compromised mice and in human killer T cells taken from people with HIV.

Guevara said a clinical trial in cancer patients could begin in about three years.

The study involved killer cells, known as CD8 T cells, and their instructor cells, known as antigen-presenting cells. The instructor cells instruct CD8 T cells to become killer T cells to kill infected cells or cancer cells -- and to remain vigilant if they reencounter pathogens or if the cancer comes back.

In addition to getting instructions from the antigen-presenting cells, CD8 T cells need assistance from helper T cells to become effective killers. Without this assistance, the killer T cells can’t do their job.

In patients who have HIV, the virus destroys helper T cells. In cancer patients, helper T cells also are affected. Among a tumor’s insidious properties is its ability to prevent killer T cells from attacking tumors. It does this by putting helper T cells into a suppressed stage, limiting their ability to assist CD8 T cells, said Andrew Zloza, MD, PhD, one of the leading authors of the study.

In the study, snippets of DNA were delivered into skin instructor cells by a device known as a gene gun. The DNA directed the instructor cells to produce specific proteins, which act like molecular keys. When CD8 T cells interact with the instructor cells, the keys unlock the CD8 T cells' killer properties -- jump-starting them to go out and kill pathogens and cancer cells.

With the use of this technique, the killer T cells would not need the assistance of helper T cells. So even if a tumor were to put the helper T cells in a suppressive cage, the killer T cells would still be able to go out and kill cancer cells. Researchers expect that future studies using the technique will make it applicable to many diseases, including cancer.

The study received major funding from the national office of the American Cancer Society, the Illinois chapter of the American Cancer Society and the National Institutes of Health.

About Loyola University Health System

Loyola University Health System (LUHS) is part of Trinity Health. Based in the western suburbs of Chicago, LUHS is a quaternary care system with a 61-acre main medical center campus, the 36-acre Gottlieb Memorial Hospital campus and more than 30 primary and specialty care facilities in Cook, Will and DuPage counties. Loyola University Medical Center’s campus is conveniently located in Maywood, 13 miles west of Chicago’s Loop and 8 miles east of Oak Brook, Ill. At the heart of the medical center campus is a 559-licensed-bed hospital that houses a Level 1 Trauma Center, a Burn Center and the Ronald McDonald® Children's Hospital of Loyola University Medical Center. Also on campus are the Cardinal Bernardin Cancer Center, Loyola Outpatient Center, Center for Heart & Vascular Medicine and Loyola Oral Health Center as well as Loyola University Chicago Stritch School of Medicine, Loyola University Chicago Marcella Niehoff School of Nursing and the Loyola Center for Fitness. Loyola's Gottlieb campus in Melrose Park includes the 255-licensed-bed community hospital, the Professional Office Building housing 150 private practice clinics, the Adult Day Care, the Gottlieb Center for Fitness, Loyola Center for Metabolic Surgery and Bariatric Care and the Loyola Cancer Care & Research at the Marjorie G. Weinberg Cancer Center at Melrose Park.

Trinity Health is a national Catholic health system with an enduring legacy and a steadfast mission to be a transforming and healing presence within the communities we serve. Trinity is committed to being a people-centered health care system that enables better health, better care and lower costs. Trinity Health has 88 hospitals and hundreds of continuing care facilities, home care agencies and outpatient centers in 21 states and 119,000 employees.