Abstract
Infection of erythrocytes with Plasmodium species induces clinical malaria. Parasite-specific CD4(+) T cells correlate with lower parasite burdens and severity of human malaria and are needed to control blood-stage infection in mice. However, the characteristics of CD4(+) T cells that determine protection or parasite persistence remain unknown. Here we show that infection of humans with Plasmodium falciparum resulted in higher expression of the inhibitory receptor PD-1 associated with T cell dysfunction. In vivo blockade of the PD-1 ligand PD-L1 and the inhibitory receptor LAG-3 restored CD4(+) T cell function, amplified the number of follicular helper T cells and germinal-center B cells and plasmablasts, enhanced protective antibodies and rapidly cleared blood-stage malaria in mice. Thus, chronic malaria drives specific T cell dysfunction, and proper function can be restored by inhibitory therapies to enhance parasite control.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, N.I.H., Intramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Acute Disease
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Animals
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Antigens, CD / drug effects*
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Antigens, CD / immunology
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B-Lymphocytes / drug effects
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B-Lymphocytes / immunology
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B-Lymphocytes / parasitology
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B7-H1 Antigen / antagonists & inhibitors*
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B7-H1 Antigen / immunology
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CD4-Positive T-Lymphocytes / drug effects*
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CD4-Positive T-Lymphocytes / immunology
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CD4-Positive T-Lymphocytes / parasitology
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Child
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Child, Preschool
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Chronic Disease
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Erythrocytes / immunology
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Erythrocytes / parasitology
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Female
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Germinal Center / drug effects
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Germinal Center / immunology
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Germinal Center / parasitology
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Humans
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Lymphocyte Activation Gene 3 Protein
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Malaria, Falciparum / drug therapy*
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Malaria, Falciparum / immunology
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Mali
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Mice
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Mice, Inbred C57BL
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Plasmodium falciparum / drug effects*
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Plasmodium falciparum / immunology
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United States
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Up-Regulation / drug effects
Substances
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Antigens, CD
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B7-H1 Antigen
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CD274 protein, human
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Cd274 protein, mouse
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Lymphocyte Activation Gene 3 Protein