The Recent Origin of Allelic Variation in Antigenic Determinants of Plasmodium falciparum

SummaryThe DNA coding for parts of the repetitive amino acid sequence of the Plasmodium falciparum circumsporozoite protein has been spliced to a sequence encoding part of the precursor to the major merozoite surface antigens, to produce a hybrid gene. Expression in Escherichia coli produces a protein with antigenic determinants from both malaria proteins. Antibodies raised against the expressed material react with both a peptide derived from the circumsporozoite repeat sequence, and the merozoite surface molecule. Hybrid molecules of this type may be the basis of a malaria vaccine.

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Cross–reactive antigenic determinants present on different Plasmodium falciparum blood–stage antigens

Parasite Immunology ◽

10.1111/j.1365-3024.1989.tb00645.x ◽

1989 ◽

Vol 11 (1) ◽

pp. 15-29 ◽

Cited By ~ 58

Author(s):

DENISE MATTEI ◽

KLAVS BERZINS ◽

MATS WAHLGREN ◽

RACHANEE UDOMSANGPETCH ◽

PETER PERLMANN ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Blood Stage ◽

Antigenic Determinants

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Recent Origin of Plasmodium falciparum from a Single Progenitor

Science ◽

10.1126/science.1059878 ◽

2001 ◽

Vol 293 (5529) ◽

pp. 482-484 ◽

Cited By ~ 120

Author(s):

S. K. Volkman

Keyword(s):

Plasmodium Falciparum ◽

Recent Origin

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Surface alterations of erythrocytes in Plasmodium falciparum malaria. Antigenic variation, antigenic diversity, and the role of the spleen.

Journal of Experimental Medicine ◽

10.1084/jem.157.4.1137 ◽

1983 ◽

Vol 157 (4) ◽

pp. 1137-1148 ◽

Cited By ~ 138

Author(s):

M Hommel ◽

P H David ◽

L D Oligino

Keyword(s):

Plasmodium Falciparum ◽

Developmental Stages ◽

Antigenic Variation ◽

Plasmodium Falciparum Malaria ◽

Immune Serum ◽

Antigenic Determinants ◽

Original Population ◽

Antigenic Diversity ◽

Immune Pressure

The surface of erythrocytes infected with late developmental stages of Plasmodium falciparum is profoundly altered and new antigenic determinants can be detected by surface immunofluorescence using immune squirrel monkey serum. The expression of these parasite-specific antigenic determinants on the surface of the host erythrocyte can be modulated by the presence or absence of the spleen and by immune pressure. An antigenic switch occurred when a cloned population of the Ugandan Palo Alto strain of P. falciparum was transferred from a splenectomized into an intact monkey and this switch was reversible. In another strain (Indochina-1), we showed that the parasites isolated during secondary and recrudescent peaks expressed erythrocyte-associated surface antigens different from the parasites isolated during the primary infection; six variant antigenic types distinct from the original population were isolated in this way. The passive transfer of immune serum can induce antigenic variation and this can occur in a cloned parasite. The various mechanisms of antigenic variation in P. falciparum are discussed in the context of strain-specific diversity and the role of antigenic diversity in acquired immunity.

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Allelic Variation in the Circumsporozoite Protein of Plasmodium falciparum from Thai Field Isolates

American Journal of Tropical Medicine and Hygiene ◽

10.4269/ajtmh.1994.51.659 ◽

1994 ◽

Vol 51 (5) ◽

pp. 659-668 ◽

Cited By ~ 30

Author(s):

Somchai Jongwutiwes ◽

Marianne K. Hughes ◽

Austin L. Hughes ◽

Hiroji Kanbara ◽

Kazuyuki Tanabe

Keyword(s):

Plasmodium Falciparum ◽

Allelic Variation ◽

Circumsporozoite Protein ◽

Field Isolates

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Genetic diversity and genotype multiplicity of Plasmodium falciparum infection in patients with uncomplicated malaria in Chewaka district, Ethiopia

10.21203/rs.2.24526/v2 ◽

2020 ◽

Author(s):

Abdulhakim Abamecha ◽

Hassan El-Abid ◽

Daniel Yilma ◽

Wondimagegn Addisu ◽

Achim Ibenthal ◽

...

Keyword(s):

Genetic Diversity ◽

Plasmodium Falciparum ◽

Malaria Control ◽

Allelic Variation ◽

Multiplicity Of Infection ◽

Chain Reactions ◽

Allelic Family ◽

Polymerase Chain Reactions ◽

Control Programmes ◽

Study Participants

Abstract Background: Genetic diversity in Plasmodium falciparum poses a major threat to malaria control and elimination interventions. Characterization of the genetic diversity of Plasmodium falciparum strains can be used to assess intensity of parasite transmission and identify potential deficiencies in malaria control programmes, which provides vital information to evaluating malaria elimination efforts. In this study, we investigated the P. falciparum genetic diversity and genotype multiplicity of infection in parasite isolates from cases with uncomplicated P. falciparum malaria in Southwest Ethiopia.Methods: A total of 80 P. falciparum microscopy and qPCR positive blood samples were collected from study participants aged six months to sixty years, who visited the health facilities during study evaluating the efficacy of arthemeter-lumefantrine from September-December, 2017. Polymorphic regions of the msp-1 and msp-2 were genotyped by nested polymerase chain reactions (nPCR) followed by gel electrophoresis for fragment analysis.Results: Of 80 qPCR-positive samples analyzed for polymorphisms on msp-1 and msp-2 genes, the efficiency of msp-1 and msp-2 gene amplification reactions with family-specific primers were 95 % and 98.8%, respectively. Allelic variation of 90% (72/80) for msp-1 and 86.2% (69/80) for msp-2 were observed. K1 was the predominant msp-1 allelic family detected in 20.8% (15/72) of the samples followed by MAD20 and RO33. Within msp-2, allelic family FC27 showed a higher frequency (26.1%) compared to IC/3D7 (15.9%). Ten different alleles were observed in msp-1 with 6 alleles for K1, 3 alleles for MAD20 and 1 allele for RO33. In msp-2, 19 individual alleles were detected with 10 alleles for FC27 and 9 alleles for 3D7. Eighty percent (80%) of isolates had multiple genotypes and the overall mean multiplicity of infection was 3.2 (95% CI: 2.87- 3.46). The heterozygosity indices were 0.43 and 0.85 for msp-1 and msp-2, respectively. There was no significant association between multiplicity of infection and age or parasite density.Conclusions: The study revealed high levels of genetic diversity and mixed-strain infections of P. falciparum populations in Chewaka district, Ethiopia, suggesting that both, endemicity level and malaria transmission remain high and that strengthened control efforts are needed in Ethiopia.

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Genetic diversity and genotype multiplicity of Plasmodium falciparum infection in patients with uncomplicated malaria in Chewaka district, Ethiopia

10.21203/rs.2.24526/v3 ◽

2020 ◽

Author(s):

Abdulhakim Abamecha ◽

Hassan El-Abid ◽

Daniel Yilma ◽

Wondimagegn Addisu ◽

Achim Ibenthal ◽

...

Keyword(s):

Genetic Diversity ◽

Plasmodium Falciparum ◽

Malaria Control ◽

Allelic Variation ◽

Multiplicity Of Infection ◽

Chain Reactions ◽

Allelic Family ◽

Polymerase Chain Reactions ◽

Control Programmes ◽

Study Participants

Abstract Background Genetic diversity in Plasmodium falciparum poses a major threat to malaria control and elimination interventions. Characterization of the genetic diversity of P. falciparum strains can be used to assess intensity of parasite transmission and identify potential deficiencies in malaria control programmes, which provides vital information to evaluating malaria elimination efforts. This study investigated the P. falciparum genetic diversity and genotype multiplicity of infection in parasite isolates from cases with uncomplicated P. falciparum malaria in Southwest Ethiopia.Methods A total of 80 P. falciparum microscopy and qPCR positive blood samples were collected from study participants aged six months to sixty years, who visited the health facilities during study evaluating the efficacy of artemether-lumefantrine from September-December, 2017. Polymorphic regions of the msp-1 and msp-2 were genotyped by nested polymerase chain reactions (nPCR) followed by gel electrophoresis for fragment analysis.Results Of 80 qPCR-positive samples analysed for polymorphisms on msp-1 and msp-2 genes, the efficiency of msp-1 and msp-2 gene amplification reactions with family-specific primers were 95 % and 98.8%, respectively. Allelic variation of 90% (72/80) for msp-1 and 86.2% (69/80) for msp-2 were observed. K1 was the predominant msp-1 allelic family detected in 20.8% (15/72) of the samples followed by MAD20 and RO33. Within msp-2, allelic family FC27 showed a higher frequency (26.1%) compared to IC/3D7 (15.9%). Ten different alleles were observed in msp-1 with 6 alleles for K1, 3 alleles for MAD20 and 1 allele for RO33. In msp-2, 19 individual alleles were detected with 10 alleles for FC27 and 9 alleles for 3D7. Eighty percent (80%) of isolates had multiple genotypes and the overall mean multiplicity of infection was 3.2 (95% CI: 2.87- 3.46). The heterozygosity indices were 0.43 and 0.85 for msp-1 and msp-2, respectively. There was no significant association between multiplicity of infection and age or parasite density.Conclusions The study revealed high levels of genetic diversity and mixed-strain infections of P. falciparum populations in Chewaka district, Ethiopia, suggesting that both endemicity level and malaria transmission remain high and that strengthened control efforts are needed in Ethiopia.

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Identification of Alleles in the MSP1 Gene Related to Complicated Malaria in Patients Infected with Plasmodium falciparum in Southeast of Iran

Journal of Arthropod-Borne Diseases ◽

10.18502/jad.v13i2.1247 ◽

2019 ◽

Author(s):

Bentol Hoda Habibi-Shorkaei ◽

Afsaneh Motevalli-Haghi ◽

Mehdi Nateghpour ◽

Leila Farivar ◽

Homa Hajjaran ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Allelic Variation ◽

Hospital Services ◽

Specific Primers ◽

Complicated Malaria ◽

Blood Smears ◽

Microscopical Method ◽

Pcr Products ◽

Msp1 Gene ◽

Sequencing Process

Background: To overcome human malaria problem several solutions have been employed including extensive studies in the field of Plasmodia relevant antigens. The aim of this study was to determine allelic variation in the MSP1 gene of Plasmodium falciparum among some falciparum malaria-infected patients in Southeastern Iran. Methods: Twenty P. falciparum positive cases were enrolled from Sistan and Baluchistan Province, southeastern Iran in 2013–15. From each case, 1.5ml of peripheral blood was collected into EDTA contained tubes. Thick and thin blood smears were stained with standard Giemsa stain and were checked with conventional microscopical method. DNA was extracted from blood samples and amplification of block 2 MSP1 was performed using specific primers. Gel electrophoresis was done and results showed some amplification fragments corresponding to block 2 regions of Pf MSP1 gene. Finally, four samples from different allelic types were sent for sequencing process. Results: Fragments were different in size, so classified into six allelic types as kinds of 1–6 based on happening frequencies. Digestion of PCR products revealed two sub allelic types (A and B) within allelic types 2 and 3, but not in allelic types 1, 4, 5 and 6. Twenty percent of samples were sent for sequencing. Sequence alignment showed 78.95% to 91.83% identity between samples. Conclusion: Identity between samples and phylogenetic tree revealed that there is an extensive diversity range among isolates. Fifty percent of the isolates were under the risk of complicated malaria. Two of these patients (10%) needed special care and recovery was obtained after getting hospital services.

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