Plasmodium infection exacts a significant toll on human public health. More than 3.3 billion people are at risk for exposure and >250 million new cases of malaria are reported each year. Much effort has been directed towards developing immunologic strategies that target the clinically relevant blood stage of Plasmodium infection, but to date no licensed vaccines exist. In rodent models of Plasmodium blood stage infection, parasite-specific CD4 T cells have been shown to be necessary for protection. In humans, the presence of parasite-specific CD4 T cells correlates with resistance to severe disease. Importantly, the precise characteristics of protective CD4 T cell responses (numbers, phenotype, functional attributes) remain largely unknown. The candidate has recently developed and applied a novel surrogate activation marker approach to track the total, parasite-specific CD4 T cell response during Plasmodium blood infection in mice, without a priori knowledge of parasite antigens, MHC restriction or epitopes. [Using this approach, the candidate has determined that Plasmodium yoelii blood stage infection results in sustained expression of multiple inhibitory receptors on responding T cells and that these cells exhibit impaired cytokine production, demonstrating that these T cells have undergone functional exhaustion during prolonged malaria. Moreover, therapeutically blocking the functional engagement of at least two inhibitor receptors with their ligands in mice with established malaria results in immediate contro of parasite replication and enhanced parasite clearance. Finally, the candidate has determined that inhibitory receptor blockade has major impacts on both parasite-specific CD4 and B cell/antibody responses during blood stage Plasmodium infection. These new results provide the necessary rationale for the proposed studies to dissect the cellular and humoral basis for enhanced parasite clearance following therapeutic inhibitory receptor blockade in mice with established clinical malaria.] The candidate has more than 10 years of experience with immunologic techniques and approaches relevant to this application. The K22 award will provide the resources necessary to advance the candidate's goal of successfully establishing an NIH R01- funded, independent laboratory to study in detail the quantitative and qualitative features of Plasmodium- specific CD4 T cell and B cell/antibody responses. Collectively, by virtue of the candidate's new approaches and methodologies, the studies detailed herein will provide critical insight into the features of anti-Plasmodial adaptive immunity that determine protection, which will impact current and future therapies and approaches to vaccine design in the context of Plasmodium infection. )

Public Health Relevance

Plasmodium infections cause 300-500 million new cases of malaria each year and exact a significant toll on global human public health, with particularly high mortality in children living in sub-Saharan Africa. CD4 T cell and antibody responses directed against the blood stage of Plasmodium infection represent critical mechanisms of host-defense against clinical malaria. The goal of this proposal is to directly examine, in quantitative and qualitative detail, the features of CD4 T cell and B cell responses necessary for resolution of prolonged blood stage Plasmodium infection.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Career Transition Award (K22)
Project #
5K22AI099070-02
Application #
8607494
Study Section
Microbiology and Infectious Diseases B Subcommittee (MID)
Program Officer
Wali, Tonu M
Project Start
2013-01-18
Project End
2014-12-31
Budget Start
2014-01-01
Budget End
2014-12-31
Support Year
2
Fiscal Year
2014
Total Cost
$108,000
Indirect Cost
$8,000
Name
University of Oklahoma Health Sciences Center
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
878648294
City
Oklahoma City
State
OK
Country
United States
Zip Code
73117
Zander, Ryan A; Guthmiller, Jenna J; Graham, Amy C et al. (2016) Type I Interferons Induce T Regulatory 1 Responses and Restrict Humoral Immunity during Experimental Malaria. PLoS Pathog 12:e1005945
Zander, Ryan A; Obeng-Adjei, Nyamekye; Guthmiller, Jenna J et al. (2015) PD-1 Co-inhibitory and OX40 Co-stimulatory Crosstalk Regulates Helper T Cell Differentiation and Anti-Plasmodium Humoral Immunity. Cell Host Microbe 17:628-41
Guthmiller, Jenna J; Zander, Ryan A; Butler, Noah S (2015) Measurement of the T Cell Response to Preerythrocytic Vaccination in Mice. Methods Mol Biol 1325:19-37
Butler, Noah S; Kulu, Divine I (2015) The regulation of T follicular helper responses during infection. Curr Opin Immunol 34:68-74
Doll, Katherine L; Butler, Noah S; Harty, John T (2014) CD8 T cell independent immunity after single dose infection-treatment-vaccination (ITV) against Plasmodium yoelii. Vaccine 32:483-91
Doll, Katherine L; Butler, Noah S; Harty, John T (2013) Tracking the total CD8 T cell response following whole Plasmodium vaccination. Methods Mol Biol 923:493-504
Butler, Noah S; Harris, Tajie H; Blader, Ira J (2013) Regulation of immunopathogenesis during Plasmodium and Toxoplasma infections: more parallels than distinctions? Trends Parasitol 29:593-602
Zander, Ryan A; Butler, Noah S (2013) Dysfunctional adaptive immunity during parasitic infections. Curr Immunol Rev 9:179-189