University Times

AIDS, T-Cell decline linked

Like a home thermostat that senses temperature changes and triggers the furnace to maintain a cozy 70 degrees, the body of an HIV-infected person senses the decline in certain immune cells (T cells) and adjusts their production to maintain a healthy number.

This finding, made by investigators at Pitt and four other U.S. institutions, was reported this summer in the journal Nature Medicine.

According to the researchers, when this homeostasis fails, the effect is chilling. The T cell number plummets, signaling that 1.5 years later the affected person will develop AIDS.

During the course of HIV infection, the virus constantly invades and destroys CD4 T cells, their primary target, but does not ravage CD8 T cells, another group of immune cells.

"We found that the immune system responds to CD4 cell depletion by 'blindly' producing both more CD4 cells and more CD8 cells, thus preserving an overall T cell count," said Albert Donnenberg, associate professor of hematology at UPMC and co-principal investigator on the research, which is part of the federally funded Multicenter AIDS Cohort Study (MACS). "Our evidence strongly suggests that breakdown of homeostasis is mechanistically linked to AIDS. It could be the event that causes the body to become vulnerable to infections that characterize AIDS." Among the other researchers involved in the study is Charles Rinaldo, head of the Pitt Men's Study, the branch of MACS at Pitt.

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Cancer vaccine effective in lab animals

Investigators at Pitt and the Dana Farber Cancer Institute have successfully vaccinated laboratory animals against cancer by harnessing an important, hitherto unexploited cellular pathway that induces the creation of potent anti-cancer immune cells (killer T cells), according to a report in the journal Nature Medicine.

"This vaccine successfully stimulates the production in mice of killer T cells that can destroy cultured cancer cells, in addition to protecting the animals against future injections with live tumor cells," said Louis Falo, Pitt assistant professor of dermatology and investigator with the University of Pittsburgh Cancer Institute. "Our findings have the potential to improve clinical cancer vaccines by effectively stimulating killer T cells, which are known to be important in attacking human cancers. The application of this type of vaccine to human cancers is at least several years away. Our next immediate step is to attempt to use this vaccine to cure mice which already have tumors." Also collaborating in the research was Kenneth Rock and M. Kovacsovics-Bankowski, both at the Dana Farber Cancer Institute in Boston, and Kathleen Thompson at Pitt.

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Pitt gets grant for training center

Pitt has received a $900,000 grant from the U.S. Department of Health and Human Services Maternal and Child Health Bureau to begin an education and training center for health professionals who care for children with neurodevelopmental and related disabilities.

The new center, University Community Leaders and Individuals with Disabilities (UCLID), will provide innovative, interdisciplinary clinical and leadership training. Pitt received one of six new grants awarded from a pool of 45 applications submitted nationally.

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Study finds no link between yo-yo dieting, heart risk

Yo-yo dieting has no adverse effect on four important cardiovascular risk factors, according to a study conducted at Pitt and the University of Minnesota.

"We found that four indices of cardiovascular health — lipid levels, blood pressure, waist-to-hip ratio and percent body fat — showed no increase in individuals who lost weight and regained it compared with those who maintained their weight over the course of the study," said Rena R. Wing, professor of psychiatry, epidemiology and psychology and principal investigator of the study. The study evaluated 148 subjects who were 30 to 70 pounds over ideal body weight and who were encouraged to lose weight over a 30-month period.

An estimated 30 percent of the U.S. population is overweight and periodically loses weight, only to regain it.

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Computer science professor given NSF grant

Panos Chrysanthis, assistant professor of computer science, has been awarded a National Science Foundation (NSF) CAREER grant of $135,000 for three years.

The grant will support study of "Developing Pragmatic Mobile Data Management Systems." The goal is to develop protocols for structuring reliable distributed systems involving data stored on both mobile and stationary computers.

The CAREER grant program replaced the NSF Young Investigators Award. Previous winners of the award in the computer science department include Rajiv Gupta, Johanna Moore, Toniann Pitassi and Martha Pollack.

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Nursing school gets grant

The School of Nursing has received a grant of more than $200,000 from The Robert Wood Johnson Foundation to study the integration of mid-level practitioners (MLPs), such as nurse practitioners and physician assistants, into acute care hospitals.

Previous studies have indicated that MLPs are effective in primary care settings. The Pitt study, one of the first of its kind, will analyze their effectiveness in acute care settings.