Identifying TB molecules

Dr Bridget Stocker (Malaghan Institute) and Dr Mattie Timmer (Victoria University of Wellington) are working to identify which specific molecules of the TB bacterium invoke immune response. Once identified, these molecules can be replicated and used to improve the efficacy of vaccines.

Transcript

DR BRIDGET STOCKER
Tuberculosis is a bacterial infection when you become infected with a bacteria. The bacteria comes in and lives in your lung. The interesting thing about TB is that they have found evidence of it in Egyptian mummies, so it’s a very, very old disease, but it’s still there. Partly because the bacteria has quite an interesting way of avoiding detection by the immune system, because it actually lives inside one of your immune cells, and it’s difficult to treat with a drug, but also because it’s got a really thick sort of waxy type coat around it, so it’s hard to get drugs in to it kill it.

The BCG vaccine is not very efficacious so it basically doesn’t work that well. I’m not sure why, but what we are looking at is actually developing new drugs as well as looking at how to improve the existing vaccine.

DR MATTIE TIMMER
Basically we are trying to find out which parts of the TB bacteria are invoking an immune response from your own body.

So a TB bacterium consists of a lot of different parts, and we are trying to focus on just taking a part of the bacterium and looking at a very specific element of the bacterium that might be used in vaccines. Of course, a lot of the bacterium is not active at all. There is water in a bacterium, which is completely harmless. There are all kinds of sugars in a bacterium that are not immunogenic, but there are very specific molecules in a bacterium that an immune response really reacts to, and we are trying to decipher which parts of the micro bacterium are actually eliciting an immune response.

The way we identify the components of a micro bacterium is via synthesis, and that is what we do. We are chemists, so we make things, we make molecules, so we are trying to sort of replicate these molecules in a very concise and defined way and then test them in biological testing or immunological testing. We are trying to then find out what the precise function of these molecules is.

It is very important in vaccination that you get a very good immune response, and if you can increase the efficacy of vaccines by adding your compound to an existing vaccine, that is one of the targets that we are pursuing.

Acknowledgement:
Janice Haney Carr, CDC Centres for Disease Control & Prevention
CDC Centres for Disease Control & Prevention