scholarly journals Antibodies to Variant Surface Antigens ofPlasmodium falciparum–Infected Erythrocytes and Adhesion Inhibitory Antibodies Are Associated with Placental Malaria and Have Overlapping and Distinct Targets

2004 ◽  
Vol 189 (3) ◽  
pp. 540-551 ◽  
Author(s):  
James G. Beeson ◽  
Emily J. Mann ◽  
Salenna R. Elliott ◽  
Valentino M. Lema ◽  
Eyob Tadesse ◽  
...  
2005 ◽  
Vol 73 (9) ◽  
pp. 5903-5907 ◽  
Author(s):  
Salenna R. Elliott ◽  
Amy K. Brennan ◽  
James G. Beeson ◽  
Eyob Tadesse ◽  
Malcolm E. Molyneux ◽  
...  

ABSTRACT Antibodies targeting variant antigens on the surfaces of chondroitin sulfate A (CSA)-binding malaria-infected erythrocytes have been linked to protection against the complications of malaria in pregnancy. We examined the isotype/subtype profiles of antibodies that bound to variant surface antigens expressed by CSA-adherent Plasmodium falciparum in pregnant Malawian women with and without histologically defined placental malaria. Women in their first pregnancy with placental malaria produced significantly greater amounts of immunoglobulin G1 (IgG1) and IgG3 reactive with surface antigens of malaria-infected erythrocytes than uninfected women of the same gravidity. IgG1 and IgG3 levels in infected and control women in later pregnancies were similar to those in infected women in their first pregnancy. Levels of IgG2 and IgG4 were similarly low in infected and uninfected women of all gravidities. IgM that bound to the surface of CSA-adherent P. falciparum occurred in all groups of women and malaria-naïve controls. There was a significant correlation between IgG1 and IgG3 levels, indicating that women usually produced both subtypes. Levels of IgG1 and IgG3 correlated with the ability of serum or plasma to inhibit parasite adhesion to CSA. Taken together, these data suggest that IgG1 and IgG3 dominate the IgG response to placental-type variant surface antigens. They may function by blocking parasite adhesion to placental CSA, but given their cytophilic nature, they might also opsonize malaria-infected erythrocytes for interaction with Fc receptors on phagocytic cells.


2009 ◽  
Vol 31 (6) ◽  
pp. 341-346 ◽  
Author(s):  
J. SOERLI ◽  
L. BARFOD ◽  
T. LAVSTSEN ◽  
N. L. BERNASCONI ◽  
A. LANZAVECCHIA ◽  
...  

2004 ◽  
Vol 72 (1) ◽  
pp. 284-294 ◽  
Author(s):  
Gerardo Cabrera ◽  
Clarisse Yone ◽  
Anne E. Tebo ◽  
Jan van Aaken ◽  
Bertrand Lell ◽  
...  

ABSTRACT We assessed immunoglobulin G (IgG) isotype responses with specificity for the variant surface antigens (VSA) of heterologous Plasmodium falciparum isolates by using flow cytometry and plasma from healthy Gabonese adults and from children during and after two consecutive malaria episodes. The individual isolate-specific antibody profiles differed markedly in terms of their isotype content but were similar for healthy adults and healthy uninfected children. In healthy adults, IgG3 and IgG2 responses were the highest, while in healthy children, IgG3 and IgG4 predominated. A transiently elevated IgG1 response was observed during the second of two successive malaria episodes in children, signaling P. falciparum infection-induced cross-reactive anti-VSA responses. Our findings highlight the prominence of IgG3 in the overall profile of these responses but also indicate a marked age-related increase in the prevalence of anti-VSA antibodies of the classically noncytophilic IgG2 isotype, possibly reflecting the high frequency of the histidine-131 variant of FcγRIIA in the Gabonese population.


2014 ◽  
Vol 8 (04) ◽  
pp. 391-402 ◽  
Author(s):  
Amanda Maestre ◽  
Jaime Carmona-Fonseca

Women pregnant with their first child are susceptible to severe P. falciparum disease from placental malaria because they lack immunity to placenta-specific cytoadherence proteins. In subsequent pregnancies, as immunity against placental parasites is acquired, there is a reduced risk of adverse effects of malaria on the mother and fetus and asymptomatic parasitaemia is common. In the case of vivax malaria, with increasing reports of severe cases in Asia and South America, the effects of infection by this species during pregnancy remain to be elucidated. This review summarized the main aspects involved in the acquisition of specific antimalarial immune responses during pregnancy with emphasis in research carried out in America and Asia, in order to offer a framework of interpretation for studies on pregnant women with malaria which are recently being produced in these regions. The authors conclude that (1) Effective humoral responses during gestational malaria are mainly directed against variant surface antigens codified by genes of the var2Csa family of P. falciparum; (2) Acquisition of immunity against these variant antigens depends on the degree and intensity of transmission, and the chance increases with age and successive pregnancies; (3) Antibody development is guided by specific cellular immune responses in cases of placental and maternal infection, and (4) The study of the significance of acquisition of specific immunity against both P. falciparum and P. vivax in America, should be performed.


PLoS ONE ◽  
2012 ◽  
Vol 7 (11) ◽  
pp. e49540 ◽  
Author(s):  
Anna Bachmann ◽  
Michaela Petter ◽  
Ann-Kathrin Tilly ◽  
Laura Biller ◽  
Karin A. Uliczka ◽  
...  

2009 ◽  
Vol 16 (3) ◽  
pp. 312-319 ◽  
Author(s):  
Anthony Jaworowski ◽  
Liselle A. Fernandes ◽  
Francisca Yosaatmadja ◽  
Gaoqian Feng ◽  
Victor Mwapasa ◽  
...  

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) coinfection decreases antibodies to variant surface antigens implicated in pregnancy-associated malaria (VSA-PAM) caused by Plasmodium falciparum. The effect of HIV-1 on antibody functions that may protect mothers from pregnancy-associated malaria is unknown. Sera from multigravid pregnant women with malaria and HIV-1 coinfection (n = 58) or malaria alone (n = 29) and from HIV-1-infected (n = 102) or -uninfected (n = 54) multigravidae without malaria were analyzed for anti-VSA-PAM antibodies by flow cytometry, the ability to inhibit adhesion to chondroitin sulfate A, or to opsonize CS2-infected erythrocytes for phagocytosis by THP-1 cells. In women with malaria, anti-VSA-PAM levels correlated better with opsonic activity (r = 0.60) than with adhesion-blocking activity (r = 0.33). In univariate analysis, HIV-1 coinfection was associated with lower opsonic activity but not adhesion-blocking activity or anti-VSA-PAM levels. Malaria-infected women with anemia (hemoglobin levels of <11.0 g/dl) had lower opsonic activity than nonanemic women (P = 0.007) independent of HIV-1 status. By multivariate analysis, in malaria-infected women, anemia (but not HIV status) was associated with opsonic activity. In women without malaria, opsonic activity was not associated with either anemia or HIV-1 status. In multigravid pregnant women with malaria, impaired serum opsonic activity may contribute to anemia and possibly to the decreased immunity to pregnancy-associated malaria associated with HIV-1.


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