scholarly journals Comparative population structure of Plasmodium falciparum circumsporozoite protein NANP repeat lengths in Lilongwe, Malawi

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Natalie M. Bowman ◽  
Seth Congdon ◽  
Tisungane Mvalo ◽  
Jaymin C. Patel ◽  
Veronica Escamilla ◽  
...  
2020 ◽  
Vol 432 (4) ◽  
pp. 1048-1063 ◽  
Author(s):  
Tossapol Pholcharee ◽  
David Oyen ◽  
Jonathan L. Torres ◽  
Yevel Flores-Garcia ◽  
Gregory M. Martin ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Merricka C. Livingstone ◽  
Alexis A. Bitzer ◽  
Alish Giri ◽  
Kun Luo ◽  
Rajeshwer S. Sankhala ◽  
...  

AbstractPlasmodium falciparum malaria contributes to a significant global disease burden. Circumsporozoite protein (CSP), the most abundant sporozoite stage antigen, is a prime vaccine candidate. Inhibitory monoclonal antibodies (mAbs) against CSP map to either a short junctional sequence or the central (NPNA)n repeat region. We compared in vitro and in vivo activities of six CSP-specific mAbs derived from human recipients of a recombinant CSP vaccine RTS,S/AS01 (mAbs 317 and 311); an irradiated whole sporozoite vaccine PfSPZ (mAbs CIS43 and MGG4); or individuals exposed to malaria (mAbs 580 and 663). RTS,S mAb 317 that specifically binds the (NPNA)n epitope, had the highest affinity and it elicited the best sterile protection in mice. The most potent inhibitor of sporozoite invasion in vitro was mAb CIS43 which shows dual-specific binding to the junctional sequence and (NPNA)n. In vivo mouse protection was associated with the mAb reactivity to the NANPx6 peptide, the in vitro inhibition of sporozoite invasion activity, and kinetic parameters measured using intact mAbs or their Fab fragments. Buried surface area between mAb and its target epitope was also associated with in vivo protection. Association and disconnects between in vitro and in vivo readouts has important implications for the design and down-selection of the next generation of CSP based interventions.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Fehintola V. Ajogbasile ◽  
Adeyemi T. Kayode ◽  
Paul E. Oluniyi ◽  
Kazeem O. Akano ◽  
Jessica N. Uwanibe ◽  
...  

Abstract Background Malaria remains a public health burden especially in Nigeria. To develop new malaria control and elimination strategies or refine existing ones, understanding parasite population diversity and transmission patterns is crucial. Methods In this study, characterization of the parasite diversity and structure of Plasmodium falciparum isolates from 633 dried blood spot samples in Nigeria was carried out using 12 microsatellite loci of P. falciparum. These microsatellite loci were amplified via semi-nested polymerase chain reaction (PCR) and fragments were analysed using population genetic tools. Results Estimates of parasite genetic diversity, such as mean number of different alleles (13.52), effective alleles (7.13), allelic richness (11.15) and expected heterozygosity (0.804), were high. Overall linkage disequilibrium was weak (0.006, P < 0.001). Parasite population structure was low (Fst: 0.008–0.105, AMOVA: 0.039). Conclusion The high level of parasite genetic diversity and low population structuring in this study suggests that parasite populations circulating in Nigeria are homogenous. However, higher resolution methods, such as the 24 SNP barcode and whole genome sequencing, may capture more specific parasite genetic signatures circulating in the country. The results obtained can be used as a baseline for parasite genetic diversity and structure, aiding in the formulation of appropriate therapeutic and control strategies in Nigeria.


2005 ◽  
Vol 102 (48) ◽  
pp. 17388-17393 ◽  
Author(s):  
F. G. Razakandrainibe ◽  
P. Durand ◽  
J. C. Koella ◽  
T. De Meeus ◽  
F. Rousset ◽  
...  

Acta Tropica ◽  
1994 ◽  
Vol 58 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Bruce H. Noden ◽  
Patrick S. Beadle ◽  
Jefferson A. Vaughan ◽  
Charles B. Pumpuni ◽  
Melissa D. Kent ◽  
...  

2022 ◽  
Vol 219 (2) ◽  
Author(s):  
Ilka Wahl ◽  
Hedda Wardemann

The induction of protective humoral immune responses against sporozoite surface proteins of the human parasite Plasmodium falciparum (Pf) is a prime goal in the development of a preerythrocytic malaria vaccine. The most promising antibody target is circumsporozoite protein (CSP). Although PfCSP induces strong humoral immune responses upon vaccination, vaccine efficacy is overall limited and not durable. Here, we review recent efforts to gain a better molecular and cellular understanding of anti-PfCSP B cell responses in humans and discuss ways to overcome limitations in the induction of stable titers of high-affinity antibodies that might help to increase vaccine efficacy and promote long-lived protection.


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