BOSTON -- The discovery that a protein present only on the surface of a select group of T-cells functions to inhibit aggressive immune responses could have important implications for organ transplant patients and patients with autoimmune diseases, and could prove equally relevant in the development of vaccines for the treatment of cancer, drug-resistant tuberculosis, HIV infections and other viral diseases. The findings from animal studies at Beth Israel Deaconess Medical Center (BIDMC) and Brigham and Women's Hospital (BWH) are described in two separate papers in the November 2003 issue of Nature Immunology.

Known as Tim-3 (T cell immunoglobulin domain, mucin domain), the proteins in question are found on the surface of TH1-helper type T cells, which when activated become the body's first line of defense against foreign microbes.

"Activated TH1-type helper T cells both participate in and help orchestrate the attack on cells bearing proteins, thereby guarding against infection," explains Terry Strom, MD, Chief of Immunology at BIDMC and Professor of Medicine at Harvard Medical School. "Nature gave us these cells as a critical defense against microbes."

However, he adds, these same T-cell responses must always be carefully balanced -- left unchecked, they can become overly aggressive, leading to inflammatory tissue injury and resultant autoimmune diseases, including diabetes, rheumatoid arthritis and inflammatory bowel disease. Similar problems develop among transplant patients when T-cells mount unnecessary defenses against their new organs, leading to organ rejection.

The two Nature Immunology papers, by senior authors Strom and BWH immunologist Vijay Kuchroo, DVM, PhD, found, for the first time, that Tim-3 proteins selectively serve as "checkpoints" for the immune system, helping to keep activated TH1 T-cell responses under control. Kuchroo is Associate Professor of Neurology at Harvard Medical School.

"Knowing that these proteins are
'"/>

Contact: Bonnie Prescott
bprescot@bidmc.harvard.edu
617-667-7306
Beth Israel Deaconess Medical Center
30-Oct-2003

Page: 1 2 3
Related medicine news :

1. Studies underscore genetic involvement in nicotine addiction & aggressive hostility
2. Studies address issues of risk and survival in rapidly increasing GI cancers
3. Studies examine coffee drinking and risk of liver and colorectal cancers
4. Studies reveal physicians attitudes on end-of-life care
5. Studies from the November issue of The Archives of Dermatology, a theme issue on facial rejuvenation
6. Studies link obesity to increased frequency of heartburn symptoms; greater risk of esophageal cancer
7. Studies demonstrate positive data in treatment of hepatitis C
8. Studies examine risk factors and potential consequences associated with prehypertension
9. Studies show ACTOS(R) (pioglitazone HCl) has positive effects on various components of dyslipidemia
10. Studies identify risk factors for colon cancer
11. Studies indicate healthy eating may affect cancer development, improve digestive system