scholarly journals Cytophilic Immunoglobulin Responses to Plasmodium falciparum Glutamate-Rich Protein Are Correlated with Protection against Clinical Malaria in Dielmo, Senegal

2000 ◽  
Vol 68 (5) ◽  
pp. 2617-2620 ◽  
Author(s):  
Claude Oeuvray ◽  
Michael Theisen ◽  
Christophe Rogier ◽  
Jean-Francois Trape ◽  
Søren Jepsen ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Protective Immunity ◽  
Clinical Malaria ◽  
Parasite Growth ◽  
Antibody Responses ◽  
Plasma Samples ◽  
Confounding Effect ◽  
Human Antibodies ◽  
Age Related ◽  
Effect Of Age

ABSTRACT The goal of this study was to analyze antibody responses toPlasmodium falciparum glutamate-rich protein (GLURP) using clinical data and plasma samples obtained from villagers of Dielmo, Senegal. This molecule was chosen because it is targeted by human antibodies which induce parasite growth inhibition in antibody-dependent cellular inhibition (ADCI) assays. The results showed a strong correlation between protection against malaria attacks and levels of immunoglobulin G2 (IgG2) and IgG3 against GLURP94–489 (R0) and IgG3 against GLURP705–1178 (R2) when corrected for the confounding effect of age-related exposure to malaria. Thus, GLURP may play a role in the induction of protective immunity against P. falciparum malaria.

scholarly journals Merozoite surface protein-3: a malaria protein inducing antibodies that promote Plasmodium falciparum killing by cooperation with blood monocytes

Blood ◽  
1994 ◽  
Vol 84 (5) ◽  
pp. 1594-1602 ◽  
Author(s):  
C Oeuvray ◽  
H Bouharoun-Tayoun ◽  
H Gras-Masse ◽  
E Bottius ◽  
T Kaidoh ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Protective Immunity ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Parasite Growth ◽  
Blood Monocytes ◽  
Protective Mechanisms ◽  
Human Antibodies ◽  
Clinical Protection ◽  
Repetitive Structure

We have previously found that the acquired protection against malaria implicates a mechanism of defense that relies on the cooperation between cytophilic antibodies and monocytes. Accordingly, an assay of antibody-dependent cellular inhibition (ADCI) of parasite growth was used as a means of selecting for molecules capable of inducing protective immunity to malaria. This allowed us to identify in the sera of clinically protected subjects an antibody specificity that promotes parasite killing mediated by monocytes. This antibody is directed to a novel merozoite surface protein (MSP-3) of a molecular mass of 48 kD. Purified IgG from protected subjects are effective in ADCI and those directed against MSP-3 are predominantly cytophilic. In contrast, in nonprotected individuals, whose antibodies are not effective in ADCI, anti-MSP-3 antibodies are mostly noncytophilic. A region in MSP-3 targetted by antibodies effective in the ADCI assay was identified and its sequence was determined; it contains an epitope not defined by a repetitive structure and does not appear to be polymorphic. Antibodies raised in mice against a peptide containing this epitope, as well as human antibodies immunopurified on this peptide, elicit a strong inhibition of Plasmodium falciparum growth in ADCI assay, whereas control antibodies, directed to peptides from other molecules, do not. The correlation between isotypes of antibodies produced against the 48- kD epitopes, clinical protection, and the ability of specific anti-MSP- 3 antibodies to block the parasite schizogony in the ADCI assay suggests that this molecule is involved in eliciting protective mechanisms.

scholarly journals Merozoite surface protein-3: a malaria protein inducing antibodies that promote Plasmodium falciparum killing by cooperation with blood monocytes

Blood ◽  
1994 ◽  
Vol 84 (5) ◽  
pp. 1594-1602 ◽  
Author(s):  
C Oeuvray ◽  
H Bouharoun-Tayoun ◽  
H Gras-Masse ◽  
E Bottius ◽  
T Kaidoh ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Protective Immunity ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Parasite Growth ◽  
Blood Monocytes ◽  
Protective Mechanisms ◽  
Human Antibodies ◽  
Clinical Protection ◽  
Repetitive Structure

Abstract We have previously found that the acquired protection against malaria implicates a mechanism of defense that relies on the cooperation between cytophilic antibodies and monocytes. Accordingly, an assay of antibody-dependent cellular inhibition (ADCI) of parasite growth was used as a means of selecting for molecules capable of inducing protective immunity to malaria. This allowed us to identify in the sera of clinically protected subjects an antibody specificity that promotes parasite killing mediated by monocytes. This antibody is directed to a novel merozoite surface protein (MSP-3) of a molecular mass of 48 kD. Purified IgG from protected subjects are effective in ADCI and those directed against MSP-3 are predominantly cytophilic. In contrast, in nonprotected individuals, whose antibodies are not effective in ADCI, anti-MSP-3 antibodies are mostly noncytophilic. A region in MSP-3 targetted by antibodies effective in the ADCI assay was identified and its sequence was determined; it contains an epitope not defined by a repetitive structure and does not appear to be polymorphic. Antibodies raised in mice against a peptide containing this epitope, as well as human antibodies immunopurified on this peptide, elicit a strong inhibition of Plasmodium falciparum growth in ADCI assay, whereas control antibodies, directed to peptides from other molecules, do not. The correlation between isotypes of antibodies produced against the 48- kD epitopes, clinical protection, and the ability of specific anti-MSP- 3 antibodies to block the parasite schizogony in the ADCI assay suggests that this molecule is involved in eliciting protective mechanisms.

scholarly journals Age-related effects on malaria parasite infection in wild chimpanzees

2013 ◽  
Vol 9 (4) ◽  
pp. 20121160 ◽  
Author(s):  
Hélène M. De Nys ◽  
Sébastien Calvignac-Spencer ◽  
Ursula Thiesen ◽  
Christophe Boesch ◽  
Roman M. Wittig ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Malaria Parasite ◽  
Strong Association ◽  
Malaria Parasites ◽  
Detection Rates ◽  
Malaria Parasite Infection ◽  
Age Related ◽  
Faecal Samples ◽  
In The Wild ◽  
Effect Of Age

Wild great apes are widely infected with a number of malaria parasites ( Plasmodium spp.). Yet, nothing is known about the biology of these infections in the wild. Using faecal samples collected from wild chimpanzees, we investigated the effect of age on Plasmodium spp. detection rates. The data show a strong association between age and malaria parasite positivity, with significantly lower detection rates in adults. This suggests that, as in humans, individuals reaching adulthood have mounted an effective protective immunity against malaria parasites.

scholarly journals Cytokine and Antibody Responses to Plasmodium falciparum in Naïve Individuals during a First Malaria Episode: Effect of Age and Malaria Exposure

PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e55756 ◽  
Author(s):  
Gemma Moncunill ◽  
Alfredo Mayor ◽  
Alfons Jiménez ◽  
Augusto Nhabomba ◽  
Laura Puyol ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Antibody Responses ◽  
Malaria Episode ◽  
Malaria Exposure ◽  
Effect Of Age

scholarly journals SARS-CoV-2 Antibody Responses Correlate with Resolution of RNAemia But Are Short-Lived in Patients with Mild Illness

2020 ◽  
Author(s):  
Katharina Röltgen ◽  
Oliver F Wirz ◽  
Bryan A Stevens ◽  
Abigail E Powell ◽  
Catherine A Hogan ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Antibody Responses ◽  
Receptor Binding Domain ◽  
Plasma Samples ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Specific Antibodies ◽  
Immune Clearance ◽  
Humoral Immune ◽  
Asymptomatic Individuals

SARS-CoV-2-specific antibodies, particularly those preventing viral spike receptor binding domain (RBD) interaction with host angiotensin-converting enzyme 2 (ACE2) receptor, could offer protective immunity, and may affect clinical outcomes of COVID-19 patients. We analyzed 625 serial plasma samples from 40 hospitalized COVID-19 patients and 170 SARS-CoV-2-infected outpatients and asymptomatic individuals. Severely ill patients developed significantly higher SARS-CoV-2-specific antibody responses than outpatients and asymptomatic individuals. The development of plasma antibodies was correlated with decreases in viral RNAemia, consistent with potential humoral immune clearance of virus. Using a novel competition ELISA, we detected antibodies blocking RBD-ACE2 interactions in 68% of inpatients and 40% of outpatients tested. Cross-reactive antibodies recognizing SARS-CoV RBD were found almost exclusively in hospitalized patients. Outpatient and asymptomatic individuals' serological responses to SARS-CoV-2 decreased within 2 months, suggesting that humoral protection may be short-lived.

scholarly journals Analysis of Human Antibodies to Erythrocyte Binding Antigen 175 of Plasmodium falciparum

2000 ◽  
Vol 68 (10) ◽  
pp. 5559-5566 ◽  
Author(s):  
Daniel M. N. Okenu ◽  
Eleanor M. Riley ◽  
Quentin D. Bickle ◽  
Philip U. Agomo ◽  
Arnoldo Barbosa ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Recombinant Proteins ◽  
Large Population ◽  
Clinical Malaria ◽  
Ligand Interaction ◽  
Human Antibodies ◽  
Multistep Process ◽  
Erythrocyte Binding ◽  
Igg3 Subclass ◽  
Region Ii

ABSTRACT Invasion of human erythrocytes by Plasmodium falciparummerozoites is a multistep process. For many strains of the parasite, part of this process requires that the erythrocyte binding antigen 175 (EBA-175) of the merozoite binds to sialic acid residues of glycophorin A on the erythrocyte surface, a receptor-ligand interaction which represents a potential target for inhibition by antibodies. This study characterizes the reactivity of naturally acquired human antibodies with four recombinant proteins representing parts of EBA-175 (region II, regions III to V, and the dimorphic C and F segment region) in populations in which the organism is endemic. Serum immunoglobulin G (IgG) recognizing the recombinant proteins is predominantly of the IgG1 and IgG3 subclasses, and its prevalence increases with age. In a large population study in The Gambia, serum positivity for IgG or IgG1 and IgG3 subclass antibodies to each of the EBA-175 recombinant antigens was not significantly associated with subsequent protection from clinical malaria. However, there was a trend indicating that individuals with high levels of IgG to region II may have some protection.

scholarly journals Antibodies to Variant Antigens on the Surfaces of Infected Erythrocytes Are Associated with Protection from Malaria in Ghanaian Children

2001 ◽  
Vol 69 (6) ◽  
pp. 3713-3718 ◽  
Author(s):  
Daniel Dodoo ◽  
Trine Staalsoe ◽  
Haider Giha ◽  
Jørgen A. L. Kurtzhals ◽  
Bartholomew D. Akanmori ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Endothelial Cells ◽  
Plasmodium Falciparum ◽  
Membrane Protein ◽  
Immunoglobulin G ◽  
Clinical Malaria ◽  
Enzyme Linked Immunosorbent Assay ◽  
Parasite Isolate ◽  
Variant Antigen ◽  
Effect Of Age

ABSTRACT Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a variant antigen expressed on the surface of infected erythrocytes. Each parasite genome contains about 40 PfEMP1 genes, but only 1 PfEMP1 gene is expressed at a given time. PfEMP1 serves as a parasite-sequestering ligand to endothelial cells and enables the parasites to avoid splenic passage. PfEMP1 antibodies may protect from disease by inhibiting sequestration, thus facilitating the destruction of infected erythrocytes in the spleen. In this study, we have measured antibodies in Ghanaian children to a conserved region of PfEMP1 by enzyme-linked immunosorbent assay and antibodies to variant molecules on erythrocytes infected with field isolates of P. falciparum by flow cytometry. Based on close clinical monitoring, the children were grouped into those who did (susceptible) and those who did not (protected) have malaria during the season. The prevalences of antibodies to both the conserved PfEMP1 peptide and the variant epitopes were greater than 50%, and the levels of immunoglobulin G (IgG) correlated with age. The levels of antibodies to both the conserved peptide and the variant epitopes were higher in protected than in susceptible children. After correcting for the effect of age, the levels of IgG to variant antigens on a Sudanese and a Ghanaian parasite isolate remained significantly higher in protected than in susceptible children. Thus, the levels of IgG to variant antigens expressed on the surface of infected erythrocytes correlated with protection from clinical malaria. In contrast, the levels of IgG to a peptide derived from a conserved part of PfEMP1 did not correlate with protection from malaria.

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