Help eliminate STDs from the world!

Did you know that chlamydia is the most common STD (or sexually transmitted disease) in Belgium and is mainly diagnosed in young people under 25? It is caused by the bacterium Chlamydia trachomatis. Because there are often no symptoms, this bacterium can spread easily, causing harmful effects. Indeed, without treatment, Chlamydia infections can cause fertility problems and chronic abdominal pain in women. In men, this infection can in turn cause epididymitis. So prevention is better than cure! Unfortunately, there is currently still no vaccine against chlamydia available and we want to change that with the Isala team… Chlamydia out of the world! How cool does that sound?

Let me give you some scientific background to clarify our mission. A vaccine consists of two parts. First is a piece of DNA from the Chlamydia bacteria, which is also called an antigen. Of course, this is not the entire bacterium and so we do not harm it when this particle enters our bodies. But by exposing this piece of the unwanted bacteria (this antigen) to our immune system, our body will produce antibodies that protect us from a possible Chlamydia infection. To get this antigen into our body you need a transport system, compare it to bpost delivering a package (piece of DNA from the Chlamydia bacteria) to the right address. This is the second component of a vaccine. In traditional vaccines, additional components are often added to get enough response from our immune system to make enough antibodies. These extra substances are called adjuvants. They often cause the well-known side effects such as headache and fever. And they are also somewhat controversial as ingredients: vaccine critics often cite them as a reason for doubt.

In my PhD, I am trying to use lactobacilli as a delivery system. Yes, I mean those good bacteria we are so keen to research. After all, in that case we don’t need to add adjuvants because these good bacteria naturally provide sufficient stimulation of our immune system. The Isala team has already done a lot of research on how these lactobacilli can boost our immune system. Besides fighting Chlamydia infections, there are other possibilities. For instance, you may remember from previous blogs that we are also very interested in preventing cervical cancer, caused by a virus (HPV). There is already a vaccine against this virus. But vaccines made with lactobacilli might well provide fewer side effects! And what else? Moreover, these bacteria would be administered via a vaginal cream, so no syringes needed!

Figure 1. Illustration of vaginal vaccination using lactobacilli. The pink oval-shaped structures represent lactobacilli. They will contain the antigens of the Chlamydia bacteria. By incorporating these bacteria into a cream and applying it to the vagina, the antigens are exposed to the immune system, causing anti-Chlamydia antibodies to be produced. These antibodies provide protection when exposed to the Chlamydia bacteria.

Is it really that simple? So why are these vaccines not yet available? Well, to make these kinds of vaccines, genetic manipulations are performed. We will insert pieces of DNA that do not come from the bacteria, in our case DNA from the Chlamydia bacteria, into lactobacilli. As the use of genetically engineered bacteria in health applications is a new technology, European legislation here is not yet sufficiently developed, and much research is being done on the safety of this new technology. So the commercialization of these ‘bacterial vaccines’ will have to wait a while.

In my research, I am therefore trying to do the necessary exploratory research to make this possible. This way, these bacteria can hopefully be used as vaccines in the future in a safe and responsible way. What do you guys think about this? Can lactobacilli eliminate chlamydia from the world?

If you have questions about STDs, you can always contact your GP or gynaecologist. There is also a lot of information on the dutch sensoa website.

Who am I?
My name is Ilke Van Tente. I started a few months ago as a PhD student in the lab of Prof. Sarah Lebeer on the iBOF project POSSIBL. I obtained a master’s degree in bioengineering in ‘Cellular and genetic engineering’ at KU Leuven. In my PhD, I like to use my knowledge on genetic engineering to improve human and women’s health. I have been following the Isala project since the beginning, so I am very excited to investigate the potential of good vaginal bacteria as an alternative vaccination strategy.