Genetic differences explain degrees of susceptibility to malaria

The Fulani people in Africa are one example of this. In a dissertation at the Wenner-Gren Institute, Stockholm University, Elisabeth Israelsson presents some important genetic differences between the Fulani and other peoples that live in the same area that may be of great importance for the development of effective protection against malaria.

The Fulani in Africa have a different genetic signature in the genes that affect how quickly and effectively the immune system can act to build up resistance to malaria. The differences between the Fulani and other peoples included in the study were clear among Fulani in both Mali and Sudan. The two groups have been separated for more than a hundred years and have differing genetic make-up, although both groups continue to evince low susceptibility to malaria. The similarities that have now been discovered in certain variations in both Fulani groups indicate that they arose at an early stage in the history of the Fulani and proved to be so beneficial in defending them against malaria that they have persisted in this ethnic group.

“What's more, we see an effect of these differences in the levels of antibodies and parasites, so we believe that these differences are important and that they can help us understand what happens with the immune system in a malaria infection,” says Elisabeth Israelsson.

It is crucial to develop antibodies against the malaria parasite to be able to resist malaria infection. It is therefore important to understand the mechanisms that influence the levels of antibodies. Among the Fulani, examinations show that they have more antibodies and a more active immune system than other African peoples living in the same area.

“If we can understand why certain individuals can produce more and/or more effective antibodies, we can also try to create new medicines or develop a new vaccine against malaria,” says Elisabeth Israelsson.

Malaria has existed as long as human beings have, and the disease has left traces in our genes that can be seen today. In her dissertation, Elisabeth Israelsson studied the minor genetic differences in genes that can be important to the immune system in a malaria infection. In particular, she looked at the difference between ethnic groups that have varying degrees of susceptibility to malaria.

The findings of the dissertation show that there are differences between the Fulani and other ethnic groups. Among other things, the genes that control how vigorously and rapidly the immune system reacts to an infection are not identical. And there is also a difference in some of the genes that govern the development of antibodies against malaria infection. The dissertation also shows that checking the immune reaction is important, since such examinations may indicate paths for new vaccine models and/or treatments for malaria.

Title of dissertation: Host genetic factors and antibody responses with potential involvement in the susceptibility to malaria. The dissertation is available for downloading as a PDF at: http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-8301

The public defense will take place at 10.00 a.m. on November 28, 2008, in Nordenskiöld Hall, Geoscience's Building, Svante Arrhenius väg 8 C, Stockholm. The external examiner is Professor Jean Langhorne, National Institute for Medical Research, Division of Parasitology, United Kingdom. The defense will be held in English.

Further information
Elisabeth Israelsson, Wenner-Gren Institute, Stockholm University, cell phone: +46 (0)73-62 474 40; phone: +46 (0)8-16 41 68; e-mail: lisa.israelsson@imun.su.se
For pictures
+46 (0)8-16 40 90 or press@su.se