Recruitment of human C1 esterase inhibitor controls complement activation on blood stage Plasmodium falciparum merozoites
Details
Publication Year 2017-05-08,Volume 198,Issue #12,Page 4728-4737
Journal Title
Journal of Immunology
Publication Type
Journal Article
Abstract
The complement system is a front-line defense system that opsonizes and lyses invading pathogens. To survive, microbes exposed to serum must evade the complement response. To achieve this, many pathogens recruit soluble human complement regulators to their surfaces and hijack their regulatory function for protection from complement activation. C1 esterase inhibitor (C1-INH) is a soluble regulator of complement activation that negatively regulates the classical and lectin pathways of complement to protect human tissue from aberrant activation. In this article, we show that Plasmodium falciparum merozoites, the invasive form of blood stage malaria parasites, actively recruit C1-INH to their surfaces when exposed to human serum. We identified PfMSP3.1, a member of the merozoite surface protein 3 family of merozoite surface proteins, as the direct interaction partner. When bound to the merozoite surface, C1-INH retains its ability to complex with and inhibit C1s, MASP1, and MASP2, the activating proteases of the complement cascade. P. falciparum merozoites that lack PfMSP3.1 showed a marked reduction in C1-INH recruitment and increased C3b deposition on their surfaces. However, these DeltaPfMSP3.1 merozoites exhibit enhanced invasion of RBCs in the presence of active complement. This study characterizes an immune-evasion strategy used by malaria parasites and highlights the complex relationship between merozoites and the complement system.
Publisher
ASI
Research Division(s)
Infection And Immunity
PubMed ID
28484054
Terms of Use/Rights Notice
Refer to copyright notice on published article.


Creation Date: 2017-05-30 09:30:47
Last Modified: 2017-09-12 11:38:13
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