News Human antibodies undermine parasite sex

12 February 2018

Some people develop an immune response following a malaria infection that stops them from infecting other mosquitos. The antibodies that these people produce are sucked up by the mosquito and destroy the malaria parasite in the mosquito’s stomach.

Teun Bousema, theme Infectious diseases and global health, and his colleagues discovered that 1 in 25 malaria patients prevent the disease from spreading in this way. They also unraveled the defense proteins responsible, and these could be used to make a vaccine. The results were published in Nature Communications on February 8th.
 
Malaria is a disease that spreads incredibly efficiently. The antimalarial medicines that are currently used cannot do much to stop this, because the parasites remain in the patient’s blood for a long time after treatment. This means that other mosquitos can be infected with the parasite if they bite the patient. The male and female parasites are fertilized in the mosquito’s stomach, the offspring are transferred back to humans when they are bitten by a mosquito, and the cycle starts again. In this way, just one malaria patient can cause more than 100 new malaria infections. In the fight against malaria, it is therefore very important to make sure that people are not able to infect other mosquitos.
 
Altruistic immunity
People who have been infected with malaria produce antibodies. These antibodies can provide protection from further infection, but they can also prevent the spread of malaria as the antibodies destroy the parasites in the mosquito’s stomach, or prevent fertilization. In that case, it is not the patient who benefits from the antibodies that he or she produces, but other people who are bitten by the mosquito. This is therefore an interesting form of altruistic immunity.
 
Malaria researcher Teun Bousema at Radboud university medical center and his colleagues at London School of Hygiene & Tropical Medicine (LSHTM), have discovered that 1 in 25 malaria patients are able to stop malaria spreading in this way. Amongst missionaries who had been infected with malaria dozens of times during their missionary work, immunity was even more common. Bousema: “This is the first time that we have been able to produce direct evidence that human antibodies against malaria parasite proteins are able to prevent the spread of malaria.”
 
Vaccine to halt spread
Research into whether people can stop the spread of malaria is incredibly labor-intensive. For each patient, dozens of mosquitos need to be investigated to see whether they have been infected after sucking up the blood of the malaria patient. Until recently, all these mosquitos needed to be dissected. Luckily, however, this problem has now been solved. Bousema: “We have developed a malaria parasite that expresses a firefly gene, allowing us to see just by looking at the mosquito whether or not it has been infected.” This has sped up the research considerably.
 
PhD student Will Stone studied people’s immune response to over 300 malaria proteins.  Stone: “We saw that our test subjects produced antibodies that are able to slow the spread of malaria in response to 45 of these proteins. People with these antibodies were ten times less likely to infect mosquitos.” Stone will defend his thesis about this research on February 22nd at Radboudumc and will continue his research at LSHTM. Bousema: “This research enables us to better understand which patients prevent the spread of malaria. We are now looking at whether it is possible to develop a malaria vaccine using some of these proteins. A vaccine that prevents the spread of malaria would help reduce the disease burden of malaria worldwide.”

Publication:
Unravelling the immune signature of Plasmodium falciparum transmission-reducing immunity
Stone WJR, Campo JJ, Ouédraogo AL, Meerstein-Kessel L, Morlais I, Da D, Cohuet A, Nsango S, Sutherland CJ, van de Vegte-Bolmer M, Siebelink-Stoter R, van Gemert GJ, Graumans W, Lanke K, Shandling AD, Pablo JV, Teng AA, Jones S, de Jong RM, Fabra-García A, Bradley J, Roeffen W, Lasonder E, Gremo G, Schwarzer E, Janse CJ, Singh SK, Theisen M, Felgner P, Marti M, Drakeley C, Sauerwein R, Bousema T, Jore MM.
Nat Commun. 2018 Feb 8;9(1):558.


Teun Bousema
 

Related news items


3 DCMN researchers among most cited scientists

10 December 2018

Christian Beckmann, Jan Buitelaar and Barbara Franke made it to this year’s list of highly cited researchers. Scientists in this list are selected for their exceptional research performance and are regarded to have had a major impact on fellow scientists.

read more

Vote for your Supervisor of the year

6 December 2018

Now you have the chance to vote for your preferred candidate. Have fun, and go for it, support and promote your ideal supervisor. The winner will be announced during the RIMLS New Year's drinks on 15 January. Deadline for voting is 1 January 2019. Here is a line up of the three nominated finalists.

read more

Discover Israels' secret to startup success

6 December 2018

International exchange of staff is an indispensable part of one’s personal and professional growth. In the context of entrepreneurship, exciting career opportunities and networking an educational and inspiring trip to Israel is planned. You are invited to join for free (only for PhD's).

read more

René Vogels Stichting travel grant for Pieter Roelofs

4 December 2018

Pieter Roelofs received the award in order to perform a work visit to prof. Reuben Harris’ lab at the University of Minnesota, USA.

read more

Symposium on inclusive research Monday 14 January 2019

4 December 2018

How does inclusive research with people with intellectual disabilities work? The academic collaborative ‘Sterker op eigen benen’ invites you to this free symposium ‘Inclusief onderzoek in ‘t eggie’ followed by the PhD defense of Tessa Frankena.

read more

MRI improves detection of prostate cancer Prostate biopsy no longer necessary for 50% of male patients

4 December 2018

There is good news for the more than 40,000 men per year who go to the hospital for diagnosis because of elevated Prostate-Specific Antigen (PSA) levels. “Thanks to the use of MRI, we can reduce the number of prostate biopsies by half,” says Jelle Barentsz.

read more
  • Go to