Tag Archives: Immune Science

Killing Caner with Genetically modified Bacteria

Researchers employ a genetically modified bacteria to eliminate tumors in mice.

The report published in February issue of the Science Translational Medicine discloses an immunological mechanism that contributes to bacteria-driven, cancer–killing activity claiming that a genetically altered Salmonella typhimurium a gastroenteritis-causing bacteria, is an effective destroyer of mouse tumors.

The reasoning behind most bacteria-driven cancer therapies is the fact that oxygen-starved and necrotic cores of tumors are attractive environments for anaerobic bacteria such as Salmonella, Clostridium, and Listeria, and an infection can lead to tumor colonization by these bugs. By means of active multiplication, the bacteria can directly kill the cancer cells and also attract the attention of the body’s immune system (which is generally suppressed within tumors), leading to further tumor destruction.

Things are not so easy and there are safety issues in implementation for patients. In a recent trial, researchers found attenuated Salmonella bacteria to be safe, but they were unable to create a strong response. To overcome the issue researchers tried to boost the potency of the Salmonella by engineering the bacteria to overexpress a protein proven to induce a strong immune response—flagellin B. As per the new report, intravenous injections of the flagellin expressing Salmonella eliminated the experimental tumors in 55 percent of mice, which then remained healthy until the end of the four-month observation period. Without overexpression of flagellin, the tumors in the mice tended to regrow after initial shrinking by the Salmonella. 

Some scientist agrees that current study extends our understanding of bacterial-based cancer therapy at a molecular level but one of the problems with developing bacterial cancer treatments has been that “these bacteria are almost a black box.” They promote cancer destruction, but no one is exactly sure how.

Source: J.H. Zheng et al., “Two-step enhanced cancer immunotherapy with engineered Salmonella typhimurium secreting heterologous flagellin,” Science Translational Medicine, 9, eaak9537, 2017.

MERS could be curable..Antibody against MERS found by Scientists


A team of Scientists have recognized a protein that worn out the MERS virus, giving the hope for a potential relief to prevent and treat the incurable disease, according to a report published in Proceedings of the National Academy of Sciences on 27th July. Middle East Respiratory Syndrome (MERS) is an exceptionally lethal pulmonary infection instigated by a formerly unidentified coronavirus (CoV), possibly passed on to humans by infected camels. There is no licensed vaccine or antiviral available so far to treat MERS, which causes symptoms such as fever, cough and shortness of breath. The team isolated a potent MERS-CoV-neutralizing antibody, named LCA60, from memory B cells of an infected patient. LCA60 antibody binds to a novel site on the spike protein and effectively nullifies infection of MERS by meddling with the binding to the cellular receptor CD26. Scientists claim that LCA60 antibody can efficiently be used for prophylaxis, for postexposure prophylaxis of individuals at risk, or for the treatment of human cases of MERS infection. Notably, LCA60, when given to infected mice, dramatically reduced the amount of the MERS virus in the lungs within days. Even in the worst-case scenario, only one virus remained after three days for every 100 viruses at the start of the treatment. In most cases, the virus became untraceable within five days of treatment. The antibody fought the virus whether it was given a day before or a day after the mice were infected. Current MERS outbreak in China and South Korea has caused 186 infections and 36 deaths as of 28th July WHO report.

See in details;

D. Corti et al. Prophylactic and postexposure efficacy of a potent human monoclonal antibody against MERS coronavirus. PNAS. Published online July 27, 2015. doi: 10.1073/pnas.151019912