The long-term goal of this research is to identify and characterize immune correlates of protection from clinical malaria in epidemic-prone highland areas. Thirty-four million individuals are estimated to be at risk for malaria outbreaks in highland areas of East Africa. Lack of specific immune responses to P. falciparum and introduction of novel parasite genotypes may be important factors in the susceptibility of these populations to malaria outbreaks. The objective of this proposal is to determine how specific measures of immunity and P. falciparum genotype relate to risk of clinical malaria in different epidemic-prone areas. The central hypothesis of this study is that, in epidemic-prone areas, transmission intensity, age and functional antibody activity are key components of protective immunity to P. falciparum, which interact with the strain causing infection to determine clinical disease.
The specific aims of this study are to: 1) determine the effect of P. falciparum transmission on antigen-specific immunity and associated protection from infection;2) identify antigen-specific immune responses protective against P. falciparum disease;and 3) elucidate the relationship of novel parasite genotype to P. falciparum disease. We will test all aims in two highland areas of Kenya with highly seasonal and sporadic transmission. We will test the first aim by comparing immune responses (IIA to MSP-119, IgG antibodies and mononuclear cell IL-4, IL-10 and IFN-g to CSP, LSA-1, TRAP, and MSP-1) between the cohorts in the two areas and comparing associated risk of new P. falciparum infection in both areas. We will test the second aim with a nested case-control study in which serum samples are obtained from the entire population in both sites and presence of immune responses is compared in individuals who do (""""""""cases"""""""") and do not (""""""""controls"""""""") develop malaria over the subsequent year. We will test the third aim by comparing frequency of specific genotypes in individuals presenting to the two site health centers with clinical malaria (""""""""cases"""""""") in 1 outbreak and 3 non-outbreak months. Genotype will be determined by PCR testing for polymorphisms in 3 antigens (MSP-1, MSP-2, and GLURP) and 4 microsatellites. We anticipate that our findings will generate strategies for vaccine induction of robust immune responses against multiple antigenic variants in vulnerable populations experiencing malaria epidemics.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project--Cooperative Agreements (U01)
Project #
5U01AI056270-06
Application #
7560060
Study Section
Special Emphasis Panel (ZRG1-IDM-H (02))
Program Officer
Rao, Malla R
Project Start
2005-05-01
Project End
2011-01-31
Budget Start
2009-02-01
Budget End
2011-01-31
Support Year
6
Fiscal Year
2009
Total Cost
$496,451
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Pediatrics
Type
Schools of Medicine
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Noland, Gregory S; Jansen, Paul; Vulule, John M et al. (2015) Effect of transmission intensity and age on subclass antibody responses to Plasmodium falciparum pre-erythrocytic and blood-stage antigens. Acta Trop 142:47-56
Frosch, Anne E P; Ondigo, Bartholomew N; Ayodo, George A et al. (2014) Decline in childhood iron deficiency after interruption of malaria transmission in highland Kenya. Am J Clin Nutr 100:968-73
Mutanda, Albino L; Cheruiyot, Priscah; Hodges, James S et al. (2014) Sensitivity of fever for diagnosis of clinical malaria in a Kenyan area of unstable, low malaria transmission. Malar J 13:163
Ondigo, Bartholomew N; Hodges, James S; Ireland, Kathleen F et al. (2014) Estimation of recent and long-term malaria transmission in a population by antibody testing to multiple Plasmodium falciparum antigens. J Infect Dis 210:1123-32
Snider, Cynthia J; Cole, Stephen R; Chelimo, Kiprotich et al. (2012) Recurrent Plasmodium falciparum malaria infections in Kenyan children diminish T-cell immunity to Epstein Barr virus lytic but not latent antigens. PLoS One 7:e31753
Rolfes, Melissa A; McCarra, Matthew; Magak, Ng'wena G et al. (2012) Development of clinical immunity to malaria in highland areas of low and unstable transmission. Am J Trop Med Hyg 87:806-12
Noland, Gregory S; Ayodo, George; Abuya, Jackson et al. (2012) Decreased prevalence of anemia in highland areas of low malaria transmission after a 1-year interruption of transmission. Clin Infect Dis 54:178-84
Ondigo, Bartholomew N; Park, Gregory S; Gose, Severin O et al. (2012) Standardization and validation of a cytometric bead assay to assess antibodies to multiple Plasmodium falciparum recombinant antigens. Malar J 11:427
Greenhouse, Bryan; Ho, Benjamin; Hubbard, Alan et al. (2011) Antibodies to Plasmodium falciparum antigens predict a higher risk of malaria but protection from symptoms once parasitemic. J Infect Dis 204:19-26
McCarra, Matthew B; Ayodo, George; Sumba, Peter O et al. (2011) Antibodies to Plasmodium falciparum erythrocyte-binding antigen-175 are associated with protection from clinical malaria. Pediatr Infect Dis J 30:1037-42

Showing the most recent 10 out of 15 publications