|Title||The role of B-cells and IgM antibodies in parasitemia, anemia, and VSG switching in Trypanosoma brucei-infected mice.|
|Publication Type||Journal Article|
|Year of Publication||2008|
|Authors||Magez, S., Schwegmann A., Atkinson R., Claes F., Drennan M., De Baetselier P., and Brombacher F.|
|Type of Article||parasites|
|Keywords||Anemia, Animals, Antibodies, Protozoan, B-Lymphocytes, Female, Immunoglobulin M, Mice, Mice, Inbred BALB C, Mice, Knockout, Parasitemia, Trypanosoma brucei brucei, Trypanosomiasis, African|
African trypanosomes are extracellular parasitic protozoa, predominantly transmitted by the bite of the haematophagic tsetse fly. The main mechanism considered to mediate parasitemia control in a mammalian host is the continuous interaction between antibodies and the parasite surface, covered by variant-specific surface glycoproteins. Early experimental studies have shown that B-cell responses can be strongly protective but are limited by their VSG-specificity. We have used B-cell (microMT) and IgM-deficient (IgM(-/-)) mice to investigate the role of B-cells and IgM antibodies in parasitemia control and the in vivo induction of trypanosomiasis-associated anemia. These infection studies revealed that that the initial setting of peak levels of parasitemia in Trypanosoma brucei-infected microMT and IgM(-/-) mice occurred independent of the presence of B-cells. However, B-cells helped to periodically reduce circulating parasites levels and were required for long term survival, while IgM antibodies played only a limited role in this process. Infection-associated anemia, hypothesized to be mediated by B-cell responses, was induced during infection in microMT mice as well as in IgM(-/-) mice, and as such occurred independently from the infection-induced host antibody response. Antigenic variation, the main immune evasion mechanism of African trypanosomes, occurred independently from host antibody responses against the parasite's ever-changing antigenic glycoprotein coat. Collectively, these results demonstrated that in murine experimental T. brucei trypanosomiasis, B-cells were crucial for periodic peak parasitemia clearance, whereas parasite-induced IgM antibodies played only a limited role in the outcome of the infection.
|Alternate Journal||PLoS Pathog.|
|PubMed Central ID||PMC2483930|
The role of B-cells and IgM antibodies in parasitemia, anemia, and VSG switching in Trypanosoma brucei-infected mice.