Dr. Rita Effros Researches Effects of Stress on Aging

People under stress seem to age faster than their cheerful, relaxed counterparts, and UCLA immunologist Rita Effros is studying why this common-sense observation has a physiological basis. ‘I wanted to look at what happens to the immune system during aging,’ said Dr. Effros, a professor of pathology and laboratory medicine at the David Geffen School of Medicine and a researcher at the UCLA AIDS Institute. ‘People over 65 are more likely to have a reemergence of a latent virus like chicken pox, which manifests itself in shingles, as well as an increased rate of breast or prostrate cancer.’ Effros wants to discover why that happens and what causes it. Researchers know that in a youthful body, T-cells (immune cells) will normally kill cells that are infected with a virus or initial-stage tumors. Researchers also know that cells age the more times they divide. In Effros’ laboratory, T-cells are taken out of the body and then manipulated into dividing repeatedly, to simulate aging. Each time a T-cell divides, part of its chromosome, called a telomere, gets shorter. ‘The telomere is like the plastic tip (aglet) on a shoelace,’ Effros explained. ‘When the cell divides, the telomere (aglet) gets shorter and when it gets too short it doesn’t protect the chromosome anymore.’ A cell with critically short telomeres becomes senescent, which is the process of deterioration with age. Once the T-cell ages, it takes on new activities and it is no longer effective in combating viruses, Effros said. ‘Certain cells which have gotten old participate in some of the diseases of aging like atherosclerosis, Alzheimer’s and even cancer.’ Before Effros began her study, previous research had been done only in labs, and the experiments showed that aged cells had shorter telomeres. Her next step was to take cells from older people and compare them to those in the laboratory dish. ‘They were similar,’ Effros said. ‘The senescent [aged] T-cells are present in an increased proportion in older people.’ Why do the telomeres shorten with aging? Effros wondered. Healthy and youthful T-cells produce an enzyme called telomerase that temporarily prevents the telomere from shortening each time the cell divides. However, at some point, the T-cells lose their ability to produce telomerase. One culprit could be stress, which stimulates the production of a hormone called cortisol. When cortisol is placed in a laboratory dish with T-cells, much less telomerase is made, which means there is nothing to prevent telomere shortening and also a T-cell is less likely to respond efficiently to an infection. Earlier researchers had taken cells from people who were under constant stress, like Alzheimer caregivers or mothers who care for chronically ill children. ‘Those people had shorter telomere lengths,’ said Effros, who believes stress can cause a body to age faster because cortisol causes less telomerase to be made and telomerase helps prevent the T-cells’ telomere from shortening. ‘Each person has to figure out how to reduce stress, whether it’s through music, meditation, exercise or yoga,’ Effros emphasized. ‘You can’t always change jobs or change the traffic, but you can change how you respond to the stresses in your life.’ Other factors besides stress that may influence telomere length are genetics and exposure to a different variety of pathogens over a lifetime. Effros also studies HIV/AIDS, which is considered a model of accelerated aging of the immune system. ‘People infected with HIV have killer T-cells that are constantly dividing in order to control the infection,’ she said. ‘Those T-cells become senescent much faster than T-cells from persons who are the same age but are not infected with HIV.’ If her research work is successful, Effros hopes that one day a pill may exist that strengthens the immune system’s ability to weather chronic emotional stress. Effros and her husband Edward, a professor in the UCLA mathematics department, have been married 41 years. They have two children: Rachael, a pediatrician who also has a master’s degree in public health and does research at The Rand Corporation on health policy, and Stephen, who is married to journalist Suzanne Pardington and is an architect in Portland.