Infection by and protective immune responses against Plasmodium berghei ANKA are not affected in macrophage scavenger receptors A deficient mice

Here we show that SR-A deficient mice and wild type mice are equally susceptible to malaria infection both during liver and blood stages. Moreover, like wild type mice, SR-A deficient mice are able to mount a protective immune response against radiation attenuated sporozoites.Our results do not reveal a function of SR-A I and II receptors in the Plasmodium berghei ANKA infection, both in the development of CM and parasitemia control. Moreover, these receptors appear not to be required for the establishment of a protective immune response against the malaria liver stages.Malaria infection starts in the mammalian host with the injection of Plasmodium sporozoites by a mosquito bite. Sporozoites travel to the liver where they cross the sinusoidal wall through Kupffer cells and then migrate through several hepatocytes before they establish an infection with the formation of a parasitophorous vacuole [1,2]. Within the vacuole the sporozoites develop and generate millions of merozoites that are released into the bloodstream. With the infection of erythrocytes the clinical phase of malaria begins. In any given year, more than a million children die as a result of malaria infection. The death from infection is largely due to an acute syndrome known as cerebral malaria (CM). The neurological manifestations of CM include headache, agitation, psychosis, seizures and impaired consciousness that lead to coma and death [3].The class A macrophage scavenger receptor (SR-A) is the prototypic member of a large family of membrane receptors that bind oxidized low density lipoprotein and a wide variety of other ligands many of which are derived from apoptotic cells and pathogens [4]. The SR-A receptors occur in two different forms that are generated by alternative splicing of the primary transcript: SR-AI and SR-AII. Both receptors have nearly identical ligand binding properties [4]. They are expressed primarily by mature cells of the myelomonocytic lineage such as Kupffer cells in the l