| 1. |
- Cherif, Mariama K., et al.
(författare)
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Is Fc gamma receptor IIA (Fc gamma RIIA) polymorphism associated with clinical malaria and Plasmodium falciparum specific antibody levels in children from Burkina Faso?
- 2015
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Ingår i: Acta Tropica. - : Elsevier BV. - 0001-706X .- 1873-6254. ; 142, s. 41-46
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, the influences of Fc gamma RIIA polymorphism on susceptibility to malaria and antibody responses to Plasmodium falciparum antigens were analyzed in children. We recruited 96 healthy children between 3 and 10 years at the beginning of the high transmission season and we followed up for 5 months through the high transmission season to assess the parasitological, immunological and genetic endpoints in relation to clinical malaria status. There was a similar distribution of homozygous and heterozygous individuals carrying the Fc gamma RIIA-131R/R and Fc gamma RIIA-131R/H allele, whereas the number of Fc gamma RIIA-131H/H homozygous individuals was lower. P. falciparum infection frequency was not associated with the Fc gamma RIIa-131R/H polymorphism. Only IgG antibody responses to GLURP R0 showed a significant association between antibody levels and Fc gamma RIIA polymorphism (p = 0.02). IgG levels to MSP2a were significantly higher in children who did not experience any clinical malaria episode compared to those who experienced at least one malaria episode (p = 0.019). Cytophilic and non-cytophylic IgG subclass levels were higher in children without malaria than those who experienced at least one malaria episode. This difference was statistically significant for IgG1 to MSP3 (p = 0.003) and to MSP2a (p = 0.006); IgG3 to MSP2a (p = 0.007) and to GLURP R0 (p = 0.044); IgG2 to MSP2b (p = 0.007) and IgG4 to MSP3 (p = 0.051) and to MSP2a (p = 0.049). In this study, homozygous carriers of the Fc gamma RIIA-131R/R allele had higher malaria-specific antibody levels compare to the heterozygous carriers Fc gamma RIIA-131R/H alleles and to homozygous carriers of Fc gamma RIIA-131H/H alleles. The pre-existing antibodies responses were related to a reduced subsequent risk of clinical malaria.
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| 2. |
- Rizzo, Cinzia, et al.
(författare)
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IgG1 and IgG4 Antibody Responses to the Anopheles gambiae Salivary Protein gSG6 in the Sympatric Ethnic Groups Mossi and Fulani in a Malaria Hyperhendemic Area of Burkina Faso
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:4, s. e96130-
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Tidskriftsartikel (refereegranskat)abstract
- Human antibody response to the Anopheles gambiae salivary protein gSG6 has recently emerged as a potentially useful tool for malaria epidemiological studies and for the evaluation of vector control interventions. However, the current understanding of the host immune response to mosquito salivary proteins and of the possible crosstalk with early response to Plasmodium parasites is still very limited. We report here the analysis of IgG1 and IgG4 subclasses among anti-gSG6 IgG responders belonging to Mossi and Fulani from Burkina Faso, two ethnic groups which are known for their differential humoral response to parasite antigens and for their different susceptibility to malaria. The IgG1 antibody response against the gSG6 protein was comparable in the two groups. On the contrary, IgG4 titers were significantly higher in the Fulani where, in addition, anti-gSG6 IgG4 antibodies appeared in younger children and the ratio IgG4/IgG1 stayed relatively stable throughout adulthood. Both gSG6-specific IgG1 and IgG4 antibodies showed a tendency to decrease with age whereas, as expected, the IgG response to the Plasmodium circumsporozoite protein (CSP) exhibited an opposite trend in the same individuals. These observations are in line with the idea that the An. gambiae gSG6 salivary protein induces immune tolerance, especially after intense and prolonged exposure as is the case for the area under study, suggesting that gSG6 may trigger in exposed individuals a Th2-oriented immune response.
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| 3. |
- Bolad, Ahmed, et al.
(författare)
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Distinct interethnic differences in IgG class/subclass and IgM antibody responses to malaria antigens but not in IgG responses to non-malarial antigens in sympatric tribes living in West Africa
- 2005
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 61:4, s. 380-386
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Tidskriftsartikel (refereegranskat)abstract
- The well-established relative resistance to malaria observed in the Fulani ascompared with other sympatric tribes in West Africa has been attributed totheir higher levels of serum immunoglobulin (Ig) G antibodies to malarialantigens. In this study, we confirm and extend the previous findings by analysesof the levels of IgM, IgG and IgG subclasses of anti-malarial antibodies inasymptomatic individuals of different sympatric tribes in Burkina Faso(Fulani/Mossi) and Mali (Fulani/Dogon). The Fulani showed significantlyhigher median concentrations of anti-malarial IgG and IgM antibodies thanthe sympatric tribes at both locations. Although the overall subclass pattern ofantibodies did not differ between the tribes, with IgG1 and IgG3 as dominant,the Fulani showed consistently significantly higher levels of these subclasses ascompared with those of the non-Fulani individuals. No significant differenceswere seen in the levels of total IgG between the tribes, but the Fulani showedsignificantly higher levels of total IgM than their neighbours in both countries.While the antibody levels to some nonmalarial antigens showed the same patternof differences seen for antibody levels to malaria antigens, no significant suchdifferences were seen with antibodies to other nonmalarial antigens. In conclusion,our results show that the Fulani in two different countries show higherlevels of anti-malarial antibodies than sympatric tribes, and this appears not tobe a reflection of a general hyper-reactivity in the Fulani.
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| 4. |
- Khanna, Chand, et al.
(författare)
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The dog as a cancer model
- 2006
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Ingår i: Nature Biotechnology. - : Springer Science and Business Media LLC. - 1087-0156 .- 1546-1696. ; 24:9, s. 1065-1066
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Tidskriftsartikel (refereegranskat)
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| 5. |
- Shelton, Jennifer M. G., et al.
(författare)
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Genetic determinants of anti-malarial acquired immunity in a large multi-centre study
- 2015
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Ingår i: Malaria Journal. - : Springer Science and Business Media LLC. - 1475-2875 .- 1475-2875. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Many studies report associations between human genetic factors and immunity to malaria but few have been reliably replicated. These studies are usually country-specific, use small sample sizes and are not directly comparable due to differences in methodologies. This study brings together samples and data collected from multiple sites across Africa and Asia to use standardized methods to look for consistent genetic effects on anti-malarial antibody levels. Methods: Sera, DNA samples and clinical data were collected from 13,299 individuals from ten sites in Senegal, Mali, Burkina Faso, Sudan, Kenya, Tanzania, and Sri Lanka using standardized methods. DNA was extracted and typed for 202 Single Nucleotide Polymorphisms with known associations to malaria or antibody production, and antibody levels to four clinical grade malarial antigens [AMA1, MSP1, MSP2, and (NANP) 4] plus total IgE were measured by ELISA techniques. Regression models were used to investigate the associations of clinical and genetic factors with antibody levels. Results: Malaria infection increased levels of antibodies to malaria antigens and, as expected, stable predictors of anti-malarial antibody levels included age, seasonality, location, and ethnicity. Correlations between antibodies to blood-stage antigens AMA1, MSP1 and MSP2 were higher between themselves than with antibodies to the (NANP)(4) epitope of the pre-erythrocytic circumsporozoite protein, while there was little or no correlation with total IgE levels. Individuals with sickle cell trait had significantly lower antibody levels to all blood-stage antigens, and recessive homozygotes for CD36 (rs321198) had significantly lower anti-malarial antibody levels to MSP2. Conclusion: Although the most significant finding with a consistent effect across sites was for sickle cell trait, its effect is likely to be via reducing a microscopically positive parasitaemia rather than directly on antibody levels. However, this study does demonstrate a framework for the feasibility of combining data from sites with heterogeneous malaria transmission levels across Africa and Asia with which to explore genetic effects on anti-malarial immunity.
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