NIAID Provides Access to Latest Immune Research Technology

Finding new ways to stimulate immunity against microbes and tumors requires knowing the cells and molecules involved in immune recognition. In particular, researchers seek to identify which molecules are recognized by which T cells, a central component of specific immune responses. To help scientists accomplish that goal, the National Institute of Allergy and Infectious Diseases (NIAID) has renewed and expanded its contract for a facility that provides tetramers, a powerful new technology in T-cell research. The facility, located at Atlanta's Emory University, will enable investigators worldwide to make rapid discoveries in vaccine research, cancer treatment and biodefense.

Tetramer technology can quickly identify those T cells involved in a given immune response. Tetramers can help scientists rapidly test the activity of new vaccines or confirm which parts of invading microbes stimulate an immune response. In cancer research, tetramers can determine which components of a tumor cell trigger the body's defenses.

Tetramers are complexes of four identical copies of the key proteins that can stimulate specific T cells. A T cell is activated when it recognizes a fragment of a target protein on the surface of a neighboring cell. Those fragments, called peptides, are held in place on the cell's surface by proteins known as MHC molecules. The T cell must grab both the peptide and the MHC molecule before it is stimulated. Tetramers are MHC-peptide complexes that have been untethered from the cell. They will attach only to T cells that recognize a specific complex and can therefore flag all T cells that respond to a given trigger.

Tetramers offer vast improvements over previous procedures for screening T-cell responses, but not all laboratories possess the resources required to synthesize and assemble the proteins. The NIAID facility at Emory provides tetramers to researchers from around the world, allowing them to conduct experiments that otherwise would be difficult or impossible to complete.

Since opening for business in 1999, the tetramer facility has provided more than 1,200 tetramers to 350 researchers from 19 different countries. Those tetramers have allowed scientists to make important discoveries about many diseases, including hepatitis C, herpes, HIV and multiple cancers.

Under the terms of the new contract, tetramer facility scientists will provide so-called class I and class II tetramers. To date, the facility has provided only class I tetramers, which are easier to synthesize and which typically identify a subset of T cells that kill infected cells and tumor cells. Class II tetramers, which will be available soon, identify the helper T cells that promote antibody production and help coordinate immune responses to infection and vaccination.

The renewed five-year contract, at an estimated $980,000 per year, will be funded by NIAID including support from the National Cancer Institute (NCI). The facility will remain under the direction of Emory's John Altman, Ph.D.

Information on the facility can be found at http://www.niaid.nih.gov/reposit/tetramer/index.html. Researchers who want to receive tetramers must first submit a request form, available on the Web site. Investigators must provide their peptide of interest, which will be incorporated into the tetramer of their choice. The service is free of charge, but recipients pay for all shipping. All researchers are eligible for reagents, not just those whose research is funded by NIAID or NCI grants.

NIAID is a component of the National Institutes of Health (NIH). NIAID supports basic and applied research to prevent, diagnose, and treat infectious and immune-mediated illnesses, including HIV/AIDS and other sexually transmitted diseases, illness from potential agents of bioterrorism, tuberculosis, malaria, autoimmune disorders, asthma and allergies.

Press releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at http://www.niaid.nih.gov.