Targeting bacteria that cause meningitis and sepsis

The work provides molecular-level information about how the antibody confers broad immunity against a variable target and suggests strategies for further improvement of available vaccines.

Our central nervous systems (brain and spinal cord) are surrounded by three membranes called “meninges.” Meningitis is caused by the swelling of these membranes, resulting in headache, fever, and neck stiffness. Most cases of meningitis in the United States are the result of viral infections and are relatively mild. However, meningitis caused by bacterial infection, if left untreated, can be deadly or lead to serious complications, including hearing loss and neurologic damage.

The bacterium responsible for meningitis (Neisseria meningitidis) can also infect the bloodstream, causing another life-threatening condition known as sepsis. N. meningitidis is spread through close contact (coughing or kissing) or lengthy contact (e.g. in dorm rooms or military barracks). In this work, researchers were interested in understanding how humans develop immunity to bacterial meningitis and sepsis, collectively known as meningococcal disease, by vaccination with a new protein-based vaccine.

>Read more on the Advanced Light Source website

Image: The work provides molecular-level information about how the antibody confers broad immunity against a variable target and suggests strategies for further improvement of available vaccines.

Insights into the development of more effective anti-tumour drug

Natural killer cells are powerful weapons our body’s immune systems count on to fight infection and combat diseases like cancer, multiple sclerosis, and lupus. Finding ways to spark these potent cells into action could lead to more effective cancer treatments and vaccines.

While several chemical compounds have shown promise stimulating a type of natural killer cells, invariant natural killer T cells (iNKT) cells in animal models, their ability to activate human iNKT cells has been limited.

Now, an international team of top immunologists, structural biologists, and chemists published in Cell Chemical Biology the creation of a new compound that appears to have the properties researchers have been looking for. The research was co-led by Monash Biomedicine Discovery Institute’s (BDI) Dr Jérôme Le Nours, University of Connecticut’s Professor Amy Howell and Albert Einstein College of Medicine’s Dr Steve Porcelli. Dr Le Nours used the Micro Crystallography beamline (MX2) at the Australian Synchrotron as part of the study.

The compound – a modified version of an earlier synthesized ligand – is highly effective in activating human iNKT cells. It is also selective – encouraging iNKT cells to release a specific set of proteins known as Th1 cytokines, which stimulate anti-tumour immunity.

>Read more on the Australian Synchrotron website

Image: 3D structure of proteins behind interaction of new drug that stimulates immune response to cancer cells. (Entire image here)

Scientists map important immune system enzyme for the first time

Biochemists from McGill University are getting a good look at just how a specific enzyme that is part of the human immune system interacts with a certain group of bacteria that are described as gram-negative.

Researchers around the world “have been studying the enzyme, known as AOAH, for more than 30 years. This is the first time anyone has been able to see exactly what it looks like,” according to Bhushan Nagar, an associate professor of biochemistry at McGill University in Montreal.

More than that, the 3D images captured a moment in time which shows just how AOAH inactivates a toxic molecule that is commonly part of various gram-negative bacteria. The research was conducted at the Canadian Light Source.

Numerous types of gram-negative bacteria exist throughout the environment. While some are harmless, many cause a variety of human illnesses, says Nagar. For example, several species such as E. coli and Salmonella, cause food borne illness. Others cause infections such as pneumonia, meningitis, bloodstream infections or gonorrhea.

>Read more on the Canadian Light Source

Image: Bhushan Nagar (principal investigator), Alexei Gorelik (first author of paper) and Katalin Illes (research assistant at Nagar lab) at their McGill University lab.
Credit: Bhushan Nagar.