[PDF][PDF] Anti-self phosphatidylserine antibodies recognize uninfected erythrocytes promoting malarial anemia

C Fernandez-Arias, J Rivera-Correa… - Cell host & …, 2016 - cell.com
Cell host & microbe, 2016cell.com
Plasmodium species, the parasitic agents of malaria, invade erythrocytes to reproduce,
resulting in erythrocyte loss. However, a greater loss is caused by the elimination of
uninfected erythrocytes, sometimes long after infection has been cleared. Using a mouse
model, we found that Plasmodium infection induces the generation of anti-self antibodies
that bind to the surface of uninfected erythrocytes from infected, but not uninfected, mice.
These antibodies recognize phosphatidylserine, which is exposed on the surface of a …
Summary
Plasmodium species, the parasitic agents of malaria, invade erythrocytes to reproduce, resulting in erythrocyte loss. However, a greater loss is caused by the elimination of uninfected erythrocytes, sometimes long after infection has been cleared. Using a mouse model, we found that Plasmodium infection induces the generation of anti-self antibodies that bind to the surface of uninfected erythrocytes from infected, but not uninfected, mice. These antibodies recognize phosphatidylserine, which is exposed on the surface of a fraction of uninfected erythrocytes during malaria. We find that phosphatidylserine-exposing erythrocytes are reticulocytes expressing high levels of CD47, a "do-not-eat-me" signal, but the binding of anti-phosphatidylserine antibodies mediates their phagocytosis, contributing to anemia. In human patients with late postmalarial anemia, we found a strong inverse correlation between the levels of anti-phosphatidylserine antibodies and plasma hemoglobin, suggesting a similar role in humans. Inhibition of this pathway may be exploited for treating malarial anemia.
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