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Harbuzariu A, Nti A, Harp KO, Cespedes JC, Driss A, Stiles JK. Neuregulin-1/ErbB4 signaling modulates Plasmodium falciparum HRP2-induced damage to brain cortical organoids. iScience 2022; 25:104407. [PMID: 35663028 PMCID: PMC9157207 DOI: 10.1016/j.isci.2022.104407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 12/21/2021] [Accepted: 05/11/2022] [Indexed: 11/30/2022] Open
Abstract
Human cerebral malaria (HCM) is a severe complication of Plasmodium falciparum (P.f.) infection that is characterized by capillary occlusions, rupture of the blood-brain barrier (BBB), perivascular cellular injury, and brain swelling. P.f.histidine-rich protein 2 (HRP2), a byproduct of parasitized red blood cell (pRBC) lysis, crosses the BBB when compromised to cause brain injury. We hypothesized that HRP2-induced neuronal damage can be attenuated by Neuregulin-1 (NRG1), an anti-inflammatory neuroprotective factor. Using brain cortical organoids, we determined that HRP2 upregulated cell death and inflammatory markers and disorganized brain organoid tissue. We identified toll-like receptors (TLR1 and 2) as potential mediators of HRP2-induced cellular damage and inflammation. Exogenous acute treatment of organoids with NRG1 attenuated HRP2 effects. The results indicate that HRP2 mediates malaria-associated HRP2-induced brain injury and inflammation and that NRG1 may be an effective therapy against HRP2 effects in the brain.
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Affiliation(s)
- Adriana Harbuzariu
- Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Annette Nti
- Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Keri Oxendine Harp
- Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Juan C. Cespedes
- Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Adel Driss
- Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Jonathan K. Stiles
- Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, Atlanta, GA 30310, USA
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HRP2: Transforming Malaria Diagnosis, but with Caveats. Trends Parasitol 2020; 36:112-126. [DOI: 10.1016/j.pt.2019.12.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/29/2019] [Accepted: 12/02/2019] [Indexed: 11/23/2022]
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Poti KE, Balaban AE, Pal P, Kobayashi T, Goldberg DE, Sinnis P, Sullivan DJ. In vivo compartmental kinetics of Plasmodium falciparum histidine-rich protein II in the blood of humans and in BALB/c mice infected with a transgenic Plasmodium berghei parasite expressing histidine-rich protein II. Malar J 2019; 18:78. [PMID: 30866956 PMCID: PMC6416945 DOI: 10.1186/s12936-019-2712-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 03/06/2019] [Indexed: 11/24/2022] Open
Abstract
Background The Plasmodium falciparum histidine-rich protein II (PfHRP2) is a common biomarker used in malaria rapid diagnostic tests (RDTs), but can persist in the blood for up to 40 days following curative treatment. The persistence of PfHRP2 presents a false positive limitation to diagnostic interpretation. However, the in vivo dynamics and compartmentalization underlying PfHRP2 persistence have not been fully characterized in the plasma and erythrocyte (RBC) fraction of the whole blood. Methods The kinetics and persistence of PfHRP2 in the plasma and RBC fractions of the whole blood were investigated post-treatment in human clinical samples and samples isolated from BALB/c mice infected with a novel transgenic Plasmodium berghei parasite engineered to express PfHRP2 (PbPfHRP2). Results PfHRP2 levels in human RBCs were consistently 20–40 times greater than plasma levels, even post-parasite clearance. PfHRP2 positive, DNA negative, once-infected RBCs were identified in patients that comprised 0.1–1% of total RBCs for 6 and 12 days post-treatment, even post-atovaquone–proguanil regimens. Transgenic PbPfHRP2 parasites in BALB/c mice produced and exported tgPfHRP2 to the RBC cytosol similar to P. falciparum. As in humans, tgPfHRP2 levels were found to be approximately 20-fold higher within the RBC fraction than the plasma post-treatment. RBC localized tgPfHRP2 persisted longer than tgPfHRP2 in the plasma after curative treatment. tgPfHRP2 positive, but DNA negative once-infected RBCs were also detected in mouse peripheral blood for 7–9 days after curative treatment. Conclusions The data suggest that persistence of PfHRP2 is due to slower clearance of protein from the RBC fraction of the whole blood. This appears to be a result of the presence PfHRP2 in previously infected, pitted cells, as opposed to PfHRP2 binding naïve RBCs in circulation post-treatment. The results thus confirm that the extended duration of RDT positivity after parasite clearance is likely due to pitted, once-infected RBCs that remain positive for PfHRP2. Electronic supplementary material The online version of this article (10.1186/s12936-019-2712-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kristin E Poti
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Amanda E Balaban
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Priya Pal
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Tamaki Kobayashi
- Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Daniel E Goldberg
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Photini Sinnis
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - David J Sullivan
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA. .,Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
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Thakur KT, Vareta J, Carson KA, Kampondeni S, Potchen MJ, Birbeck GL, MacCormick I, Taylor T, Sullivan DJ, Seydel KB. Cerebrospinal fluid Plasmodium falciparum histidine-rich protein-2 in pediatric cerebral malaria. Malar J 2018; 17:125. [PMID: 29566695 PMCID: PMC5865338 DOI: 10.1186/s12936-018-2272-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 03/14/2018] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Cerebral malaria (CM) causes a rapidly developing coma, and remains a major contributor to morbidity and mortality in malaria-endemic regions. This study sought to determine the relationship between cerebrospinal fluid (CSF) Plasmodium falciparum histidine rich protein-2 (PfHRP-2) and clinical, laboratory and radiographic features in a cohort of children with retinopathy-positive CM. METHODS Patients included in the study were admitted (2009-2013) to the Pediatric Research Ward (Queen Elizabeth Central Hospital, Blantyre, Malawi) meeting World Health Organization criteria for CM with findings of malarial retinopathy. Enzyme-linked immunosorbent assay was used to determine plasma and CSF PfHRP-2 levels. Wilcoxon rank-sum tests and multivariable logistic regression analysis assessed the association of clinical and radiographic characteristics with the primary outcome of death during hospitalization. RESULTS In this cohort of 94 patients, median age was 44 (interquartile range 29-62) months, 53 (56.4%) patients were male, 6 (7%) were HIV-infected, and 10 (11%) died during hospitalization. Elevated concentrations of plasma lactate (p = 0.005) and CSF PfHRP-2 (p = 0.04) were significantly associated with death. On multivariable analysis, higher PfHRP-2 in the CSF was associated with death (odds ratio 9.00, 95% confidence interval 1.44-56.42) while plasma PfHRP-2 was not (odds ratio 2.05, 95% confidence interval 0.45-9.35). CONCLUSIONS Elevation of CSF, but not plasma PfHRP-2, is associated with death in this paediatric CM cohort. PfHRP-2 egress into the CSF may represent alteration of blood brain barrier permeability related to the sequestration of parasitized erythrocytes in the cerebral microvasculature.
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Affiliation(s)
- Kiran T Thakur
- Division of Critical Care and Hospitalist Neurology, Department of Neurology, Columbia University Medical Center, 177 Fort Washington Avenue, Milstein Hospital, 8GS-300, New York, NY, 10032, USA.
| | - Jimmy Vareta
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi.
| | - Kathryn A Carson
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Samuel Kampondeni
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- Neuroradiology Division, Department of Imaging Sciences, University of Rochester, Rochester, NY, USA
- Queen Elizabeth Central Hospital, Blantyre, Malawi
| | - Michael J Potchen
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- Neuroradiology Division, Department of Imaging Sciences, University of Rochester, Rochester, NY, USA
| | - Gretchen L Birbeck
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- Epilepsy Division, Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA
| | - Ian MacCormick
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Eye and Vision Science, University of Liverpool, Liverpool, UK
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Terrie Taylor
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA
| | - David J Sullivan
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Karl B Seydel
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA
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Park GS, Opoka RO, Shabani E, Wypyszynski A, Hanisch B, John CC. Plasmodium falciparum Histidine-Rich Protein-2 Plasma Concentrations Are Higher in Retinopathy-Negative Cerebral Malaria Than in Severe Malarial Anemia. Open Forum Infect Dis 2017; 4:ofx151. [PMID: 28948179 PMCID: PMC5597884 DOI: 10.1093/ofid/ofx151] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/14/2017] [Indexed: 11/14/2022] Open
Abstract
Background Malaria retinopathy has been proposed as marker of “true” cerebral malaria (CM), ie, coma due to Plasmodium falciparum vs coma due to other causes, with incidental P falciparum parasitemia. Plasma P falciparum histidine-rich protein-2 (PfHRP2) concentrations distinguish retinopathy-positive (RP) from retinopathy-negative (RN) CM but have not been compared between RN CM and other forms of severe malaria or asymptomatic parasitemia (AP). Methods We compared plasma PfHRP2 concentrations in 260 children with CM (247 examined for retinopathy), 228 children with severe malarial anemia (SMA), and 30 community children with AP. Results Plasmodium falciparum HRP2 concentrations were higher in children with RP CM than RN CM (P = .006), with an area under the receiver operating characteristic curve of 0.61 (95% confidence interval, 0.53–0.68). Plasmodium falciparum HRP2 concentrations and sequestered parasite biomass were higher in RN CM than SMA (both P < .03) or AP (both P < .001). Conclusions Plasmodium falciparum HRP2 concentrations are higher in children with RN CM than in children with SMA or AP, suggesting that P falciparum is involved in disease pathogenesis in children with CM. Plasmodium falciparum HRP2 concentrations may provide a more feasible and consistent assessment of the contribution of P falciparum to severe disease than malaria retinopathy.
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Affiliation(s)
- Gregory S Park
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis
| | - Robert O Opoka
- Makerere University College of Health Sciences, Kampala, Uganda
| | - Estela Shabani
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis.,Ryan White Center for Pediatric Infectious Diseases and Global Health, Indiana University School of Medicine, Indianapolis
| | - Alexis Wypyszynski
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis
| | - Benjamin Hanisch
- Division of Pediatric Infectious Diseases, Children's National Medical Center, Washington, District of Columbia
| | - Chandy C John
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis.,Ryan White Center for Pediatric Infectious Diseases and Global Health, Indiana University School of Medicine, Indianapolis
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Taylor DW, Bobbili N, Khadka VS, Quakyi IA, Leke RGF. Individuals living in a malaria-endemic area of Cameroon do not have an acquired antibody response to Plasmodium falciparum histidine-rich protein 2. Malar J 2017; 16:58. [PMID: 28148260 PMCID: PMC5286799 DOI: 10.1186/s12936-017-1704-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 01/19/2017] [Indexed: 12/02/2022] Open
Abstract
Background Diagnosis of Plasmodium falciparum is often based on detection of histidine-rich protein 2 (HRP2) in blood. Most HRP2-based assays have high sensitivity and specificity; however, authors have suggested that antibodies (Ab) to HRP2 could reduce assay sensitivity. This study sought to characterize the antibody response to HRP2 with respect to prevalence, class, subclass, affinity, and age distribution in Cameroonian children and adults residing in an area with high P. falciparum transmission. Methods Plasma samples from 181 Cameroonian children and adults who had been repeatedly exposed to P. falciparum and 112 samples from American adults who had never been exposed were tested for IgG Ab to HRP2. For comparison, Ab to the merozoite antigens MSP1, MSP2, MSP3 and the pregnancy-associated antigen VAR2CSA were measured using a multiplex bead-based assay. In addition, 81 plasma samples from slide-positive individuals were screened for IgM Ab to HRP2. Results As expected, children and adults had IgG Ab to MSP1, MSP2 and MSP3, antibody levels increased with age, and only women of child-bearing age had Ab to VAR2CSA; however, no convincing evidence was found that these individuals had an acquired antibody response to HRP2. That is, using two sources of recombinant HRP2, identical results were obtained when plasma from 110 Cameroonian adults and 112 US adults were screened for IgG Ab. Further studies showed that antibody prevalence and levels did not increase with age in Cameroonians between ages 5 and >80 years. Although a few samples from slide-positive Cameroonians had IgM values slightly above the American cut-off, it was unclear if the individuals had a true IgM response to HRP2 or if the values were due to non-specific binding from elevated immunoglobulin levels associated with infection. Data from prediction models showed a paucity of Class II T cell epitopes in HRP2. Conclusions These data support the conclusion that most individuals in malaria-endemic areas do not produce an acquired humoral response to HRP2. The absence of Ab helps explain why HRP2-based assays are able to detect nanogram amounts of HRP2 and why HRP2 continues to circulate for a long time after parasite clearance.
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Affiliation(s)
- Diane Wallace Taylor
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii at Manoa, 561 Ilalo Street, Honolulu, HI, 96813, USA.
| | - Naveen Bobbili
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii at Manoa, 561 Ilalo Street, Honolulu, HI, 96813, USA
| | - Vedbar S Khadka
- Office of Biostatistics & Quantitative Health Sciences, John A. Burns School of Medicine, University of Hawaii at Manoa, 561 Ilalo Street, Honolulu, HI, 96813, USA
| | - Isabella A Quakyi
- Department of Biological, Environmental and Occupational Health Sciences, School of Public Health, College of Health Sciences, University of Ghana, Legon, P.O. Box LG 13, Accra, Ghana
| | - Rose G F Leke
- Faculty of Medicine and Biomedical Sciences, Biotechnology Center, University of Yaoundé I, Yaoundé, Cameroon
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Patarroyo ME, Alba MP, Rojas-Luna R, Bermudez A, Aza-Conde J. Functionally relevant proteins in Plasmodium falciparum host cell invasion. Immunotherapy 2017; 9:131-155. [DOI: 10.2217/imt-2016-0091] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A totally effective, antimalarial vaccine must involve sporozoite and merozoite proteins (or their fragments) to ensure complete parasite blocking during critical invasion stages. This Special Report examines proteins involved in critical biological functions for parasite survival and highlights the conserved amino acid sequences of the most important proteins involved in sporozoite invasion of hepatocytes and merozoite invasion of red blood cells. Conserved high activity binding peptides are located in such proteins’ functionally strategic sites, whose functions are related to receptor binding, nutrient and protein transport, enzyme activity and molecule–molecule interactions. They are thus excellent targets for vaccine development as they block proteins binding function involved in invasion and also their biological function.
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Affiliation(s)
- Manuel E Patarroyo
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26–20 Bogotá, Colombia
- Universidad Nacional de Colombia, Bogotá DC, Colombia
| | - Martha P Alba
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26–20 Bogotá, Colombia
- Universidad de Ciencias Aplicadas y Ambientales (UDCA), Bogotá, Colombia
| | - Rocío Rojas-Luna
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26–20 Bogotá, Colombia
| | - Adriana Bermudez
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26–20 Bogotá, Colombia
- Universidad del Rosario, Bogotá DC, Colombia
| | - Jorge Aza-Conde
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26–20 Bogotá, Colombia
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Seydel KB, Fox LL, Glover SJ, Reeves MJ, Pensulo P, Muiruri A, Mpakiza A, Molyneux ME, Taylor TE. Plasma concentrations of parasite histidine-rich protein 2 distinguish between retinopathy-positive and retinopathy-negative cerebral malaria in Malawian children. J Infect Dis 2012; 206:309-18. [PMID: 22634877 DOI: 10.1093/infdis/jis371] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Brain histology and ophthalmoscopy suggest that approximately 25% of children with World Health Organization-defined cerebral malaria (CM) have a nonmalarial cause of death. Misclassification complicates clinical care, confounds studies of association, and may obfuscate successes in malaria control. Retinopathy predicts intracerebral parasite sequestration with >90% sensitivity and specificity, but detecting retinopathy requires well-trained personnel and expensive equipment. METHODS We investigated the utility of plasma concentrations of parasite histidine-rich protein 2 (pHRP2), a Plasmodium-specific protein, as a predictor of intracerebral parasite sequestration at autopsy and of malaria retinopathy on clinical examination in patients with clinically defined CM. RESULTS In 64 autopsy cases, 47 of whom had histological evidence of sequestration, the sensitivity and specificity of a plasma pHRP2 level of >1700 ng/mL were 98% and 94%, respectively, and the area under the receiver operating characteristic (AUROC) curve was 0.98. In a separate, prospectively studied group of 101 children with clinically defined CM, of whom 71 had retinopathy, the same pHRP2 cutoff predicted retinopathy-positivity with a sensitivity of 90% and specificity of 87% (AUROC, 0.90). CONCLUSIONS Elevated plasma pHRP2 concentrations can identify Malawian children with histologically confirmed or retinopathy-positive CM and is a more field-friendly approach to confirming the diagnosis than post mortem sampling or ophthalmoscopy.
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Affiliation(s)
- Karl B Seydel
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre.
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Abstract
Histidine-rich protein II (HRPII) is an abundant protein released into the bloodstream by Plasmodium falciparum, the parasite that causes the most severe form of human malaria. Here, we report that HRPII binds tightly and selectively to coagulation-active glycosaminoglycans (dermatan sulfate, heparan sulfate, and heparin) and inhibits antithrombin (AT). In purified systems, recombinant HRPII neutralized the heparin-catalyzed inhibition of factor Xa and thrombin by AT in a Zn(2+)-dependent manner. The observed 50% inhibitory concentration (IC(50)) for the HRPII neutralization of AT activity is approximately 30nM for factor Xa inhibition and 90nM for thrombin inhibition. Zn(2+) was required for these reactions with a distribution coefficient (K(d)) of approximately 7μM. Substituting Zn(2+) with Cu(2+), but not with Ca(2+), Mg(2+), or Fe(2+), maintained the HRPII effect. HRPII attenuated the prolongation in plasma clotting time induced by heparin, suggesting that HRPII inhibits AT activity by preventing its stimulation by heparin. In the microvasculature, where erythrocytes infected with P falciparum are sequestered, high levels of released HRPII may bind cellular glycosaminoglycans, prevent their interaction with AT, and thereby contribute to the procoagulant state associated with P falciparum infection.
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Antibody and cellular immune responses to Plasmodium falciparum histidine-rich protein II in malaria-exposed individuals in Orissa, India. Trans R Soc Trop Med Hyg 2010; 104:371-3. [PMID: 20116080 DOI: 10.1016/j.trstmh.2010.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2009] [Revised: 12/28/2009] [Accepted: 01/04/2010] [Indexed: 11/20/2022] Open
Abstract
The precise function of Plasmodium falciparum histidine-rich protein II (HRPII) is not known, but in vitro studies have indicated its immunomodulatory function. The host immune response to HRPII was measured and compared with the response to P. falciparum merozoite surface protein 1 (MSP1) in four groups of study subjects (healthy malaria-naïve adults, uncomplicated malaria patients, asymptomatic parasite carriers and aparasitemic endemic adults; n=15 in each group). Serum antibody concentrations, lymphocyte proliferation and IFN-( and IL-4 responses were significantly higher with MSP1 than with HRPII stimulation in all three malaria-exposed groups (P<0.001), suggesting a strong immunomodulatory role for HRPII.
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Mishra A, Panda JJ, Basu A, Chauhan VS. Nanovesicles based on self-assembly of conformationally constrained aromatic residue containing amphiphilic dipeptides. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:4571-6. [PMID: 18358051 DOI: 10.1021/la7034533] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Peptide-based vesicular structures have been the focus of research in the past decade for their potential application as drug delivery agents. We here report the self-assembly of amphiphilic dipeptides containing conformation-constraining alpha,beta-dehydrophenylalanine into nanovesicles. The vesicles can encapsulate small drug molecules such as riboflavin and vitamin B(12), bioactive peptides, and small protein molecules. The nanovesicles are resistant to treatment of a nonspecific protease, proteinase K, and are stable at low concentrations of monovalent and divalent cations. The vesicles are effectively taken up by actively growing cells in culture and show no observable cytopathic effects. These peptide-based nanostructures can be considered as models for further development as delivery agents for different biomolecules.
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Affiliation(s)
- Aseem Mishra
- International Centre for Genetic Engineering and Biotechnology, New Delhi, and National Institute of Virology, Pune, India
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