A pioneering approach to imaging breast cancer in mice has revealed new clues about why the human immune systemoften fails to attack tumors and keep cancer in check. This observation, by scientists at the University ofCalifornia, San Francisco (UCSF), may help to reveal new approachesto cancer immunotherapy. Published in the journal Cancer Cell , the work shows that the body's natural defenses trip overthemselves on their way to attacking a tumor. The activated immunecells, alerted to the threat of the tumor, should make their way tothe site of the cancer and then attack and shrink the tumor. Instead, these immune cells are headed off at the pass. Acompletely separate set of healthy cells that are already incontact with the tumor effectively establish a defensive perimeteraround it. There, like a thin red line between cancer and health,they head off the killer immune cells and keep them at bay outsidethe tumor. "These cells are forming a last line of defense for the tumoragainst incoming cytotoxic cells," said Matthew Krummel, PhD, anassociate professor of pathology and a principal investigator inthe UCSF Helen Diller Family Comprehensive Cancer Center. The discovery adds a rich layer of understanding of how the immunesystem interacts with breast cancer, knowledge that may ultimatelyhelp researchers find better ways to treat the disease, saidKrummel. Future immunotherapy cancer treatments could be made moreeffective on their own or in combination with other drugs, he said,if researchers can find a way to enhance the ability of T cells tomake it through this tumor defense. Unlocking the Secrets of Cancer Cracking open a crashed airplane's black box to parse its flightdata and recreate its final few seconds is a powerful way of askinghow improvements could be made to aviation safety. Biologists wouldlike to do essentially the same thing with cancer: to liberate thedata, see what went wrong and use that knowledge to find new waysto improve human health. Because biology has no flight recorders, modern researchers lookbroadly at the genetics of large populations, or tease apart themolecular markers within tumors or closely following the disease asit develops in laboratory models. Krummel and his colleagues developed a way to produce differentfluorescent-colored dyes in breast cancer tumors and the variouscells around them, They then used a special microscope to image andtrack immune cells as they moved in and out of breast cancer tumorsthat arise spontaneously in the mouse. "We can see each of themarise, see where they are in the tumor and watch their directinteraction with immune cells in real time," he said. What they found was that the interaction between breast cancer andthe immune system is marked by missed opportunities. Fighting cancer is one of the things the immune system is designedto do, in numerous ways. One of these is by unleashing a set ofactors known as killer T cells, which can destroy tumors byattacking their cells en mass. The success of this mechanism canmean the difference between a tumor that withers away and one thatcontinues to grow to more advanced stages. But the scene Krummel and his colleagues watched unfold under theirmicroscopes revealed a subset of specialized "dendritic" cells thatthey were then able to extensively study. With the fluoroscentlabeling technique they devised, they were able to purify justthese cells and observe how they dampen the killer T cellresponses. As Krummel and his colleagues showed, these cells deactivatedapproaching killer cells, stifling them before they could springinto action. This set of experiments is critical for cancer immunobiologists,said Krummel, because the data is the first to positively identifya partner for the incoming killer T cells. The fact that theinteraction dampens the potency of the killer cells makes thedendritic cells a valuable target for future therapeutics. Additional References Citations. The e-commerce company in China offers quality products such as Pine Oil Disinfectant , Dipentene, and more. For more , please visit Pine Oil Cleaner today!
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