Researchers have gained important clues about immune system responses that could play a role in protecting people from HIV infection in follow-up studies from the world's largest HIV vaccine trial to date. Results from laboratory studies based on the trial were published in the New England Journal of Medicine. The HIV vaccine trial in Thailand, called RV144, showed that the group receiving the vaccine regimen was estimated to be 31.2 percent less likely to be infected than those who didn't get the vaccine, and researchers set out to learn why. Researchers analyzed samples from RV144 trial participants to look at immune responses in the vaccine recipients. The researchers found that different types of antibody responses were associated with a higher or lower rate of HIV infection. "By studying those who became infected compared to those who did not, we believe we have found very important clues for how the RV144 trial might have worked, " said Barton F.
A Ray Of Sunshine For The Critically Ill: Vitamin D Deficiency Is Associated With Increased Mortality In Intensive Care Patients
Scientists have long believed that vitamin D, which is naturally absorbed from sunlight, has an important role in the functioning of the body's autoimmune system. Now Prof. Howard Amital of Tel Aviv University's Sackler Faculty of Medicine and Sheba Medical Center has discovered that the vitamin may also affect the outcomes of patients in intensive care. In a six-month study, Prof. Amital and his colleagues found that patients who had a vitamin D deficiency lived an average of 8.9 days less than those who were found to have sufficient vitamin D. Vitamin D levels also correlated with the level of white blood cells which fight disease. The study, which was published in the journal QJM: An International Journal of Medicine, demonstrates further research into giving patients vitamin D could confirm that it will improve their survival outcomes.
Neutrophil granulocytes comprise important defences for the immune system. When pathogenic bacteria penetrate the body, they are the first on the scene to mobilise other immune cells via signal molecules, thereby containing the risk. To this end, they release serine proteases - enzymes that cut up other proteins to activate signal molecules. Scientists at the Max Planck Institute of Neurobiology in Martinsried have now discovered a new serine protease: neutrophil serine protease 4, or NSP4. This enzyme could provide a new target for the treatment of diseases that involve an overactive immune system, such as rheumatoid arthritis. The functioning of the immune system is based on the complex interplay of the most diverse cells and mediators. For example, neutrophil granulocytes (a group of specialized white blood cells) react to bacteria by releasing substances called serine proteases.
A team led by scientists at The Scripps Research Institute has found antibodies that can prevent infection from widely differing strains of hepatitis C virus (HCV) in cell culture and animal models. HCV's very high rate of mutation normally helps it to evade its host's immune system. The newly discovered antibodies, however, attach to sites on the viral envelope that seldom mutate. One of the new antibodies, AR4A, shows broader HCV neutralizing activity than any previously reported anti-HCV antibody. "These antibodies attach to sites on the viral envelope that were previously unknown, but now represent promising targets for an HCV vaccine, " said Mansun Law, an assistant professor at Scripps Research. Law is the senior author of the new report, which appears online this week in the Proceedings of the National Academy of Sciences.
Scientists may have discovered a new paradigm for immunotherapy against cancer by priming antibodies and T cells with cancer stem cells, according to a study published in Cancer Research, a journal of the American Association for Cancer Research. "This is a major breakthrough in immunotherapy research because we were able to use purified cancer stem cells to generate a vaccine, which strengthened the potency of antibodies and T cells that selectively targeted cancer stem cells, " said Qiao Li, Ph.D., a research assistant professor in the department of surgery at the University of Michigan. Cancer stem cells are tumor cells that remain present, and ultimately resistant, after chemotherapy or radiation treatment. Scientists disagree on whether these cells have unique properties, but those who support the uniqueness idea have argued that these cells regenerate the tumors that lead to relapse.