Duffy antigen

BACKGROUND: The Plasmodium vivax merozoite restrictively invades immature erythrocytes, suggesting that its ligand(s) might interact with corresponding receptor(s) that are selectively abundant on reticulocytes to complete the invasion. Finding the ligand‒receptor interaction involved in P. vivax invasion is critical to vivax malaria management; nevertheless, it remains to be unraveled. METHODS: A library of reticulocyte receptors and P. vivax ligands were expressed by a HEK293E mammalian cell expression system and were then used to screen the interaction using enzyme-linked immunosorbent assay (ELISA)...

Red blood cell (RBC) alloimmunization to paternal antigens during pregnancy can cause hemolytic disease of the fetus and newborn (HDFN). This severe and potentially fatal neonatal disorder can be prevented by the administration of polyclonal anti-D through a mechanism referred to as antibody-mediated immune suppression (AMIS). Although anti-D prophylaxis effectively prevents HDFN, a lack of mechanistic clarity has hampered its replacement with recombinant agents. The major theories behind AMIS induction in the hematological literature have classically centered around RBC clearance, however antigen modulation/loss has recently been proposed as a potential mechanism of AMIS...

Placental malaria vaccines (PMVs) are being developed to prevent severe sequelae of placental malaria (PM) in pregnant women and their offspring. The leading candidate vaccine antigen VAR2CSA mediates parasite binding to placental receptor chondroitin sulfate A (CSA). Despite promising results in small animal studies, recent human trials of the first two PMV candidates (PAMVAC and PRIMVAC) generated limited cross-reactivity and cross-inhibitory activity to heterologous parasites. Here we immunized Aotus nancymaae monkeys with three PMV candidates (PAMVAC, PRIMVAC and ID1-ID2a_M1010) adjuvanted with Alhydrogel, and exploited the model to investigate boosting of functional vaccine responses during PM episodes as well as with nanoparticle antigens...

BACKGROUND: Accurate blood type data are essential for blood bank management, but due to costs, few of 43 blood group systems are routinely determined in Danish blood banks. However, a more comprehensive dataset of blood types is useful in scenarios such as rare blood type allocation. We aimed to investigate the viability and accuracy of predicting blood types by leveraging an existing dataset of imputed genotypes for two cohorts of approximately 90,000 each (Danish Blood Donor Study and Copenhagen Biobank) and present a more comprehensive overview of blood types for our Danish donor cohort...

Despite historical dogma that Duffy blood group negativity of human erythrocytes confers resistance to Plasmodium vivax blood stage infection, cases of P. vivax malaria and asymptomatic blood stage infection (subclinical malaria) have recently been well documented in Duffy-negative individuals throughout Africa. However, the impact of Duffy negativity on the development of naturally acquired immunity to P. vivax remains poorly understood. We examined antibody reactivity to P. vivax and P. falciparum antigens at two field sites in Ethiopia and assessed Duffy gene expression by polymerase chain reaction amplification and sequencing of the GATA-1 transcription factor-binding site of the Duffy antigen receptor for chemokines (DARC) gene promotor region that is associated with silencing of erythroid cell transcription and absent protein expression...

Molecular analysis of blood groups is important in transfusion medicine, allowing the prediction of red blood cell (RBC) antigens. Many blood banks use single nucleotide variant (SNV) based methods for blood group analysis. While this is a well-established approach, it is limited to the polymorphisms included in genotyping panels. Thus, variants that alter antigenic expression may be ignored, resulting in incorrect prediction of phenotypes. The popularization of next-generation sequencing (NGS) has led to its application in transfusion medicine, including for RBC antigens determination...

Finding a compatible donor for kidney transplant candidates requires overcoming immunological barriers such as human leukocyte antigens (HLA) compatibility and ABO compatibility. Emerging data suggest a role for red blood cell antigens (RCA) in renal transplant outcomes. The incidence of RCA alloimmunization is high in chronically transfused individuals, such as end stage renal disease patients, but whether antibodies to RCA can mediate renal graft rejection remains debatable. The Duffy blood group antigens (Fy) has been shown to be expressed in the kidney, among other tissues...

Plasmodium knowlesi ( Pk ) causes zoonotic malaria and is known as the "fifth human malaria parasite". Pk malaria is an emerging threat because infections are increasing and can be fatal. While most infections are in Southeast Asia (SEA), especially Malaysia, travelers frequently visit this region and can present with Pk malaria around the world. So, clinicians need to know (1) patients who present with fever after recent travel to SEA might be infected with Pk and (2) Pk is often misdiagnosed as P. malariae (which typically causes less severe malaria)...

The Duffy protein, a transmembrane molecule, functions as a receptor for various chemokines and facilitates attachment between the reticulocyte and the Plasmodium Duffy antigen-binding protein. Duffy expression correlates with the Duffy receptor gene for the chemokine, located on chromosome 1, and exhibits geographical variability worldwide. Traditionally, researchers have described the Duffy negative genotype as a protective factor against Plasmodium vivax infection. However, recent studies suggest that this microorganism's evolution could potentially diminish this protective effect...

The discovery of the Duffy antigen is of great significance, given its essential role in immune response and various physiological processes. Genetic mutations in the Duffy gene not only affect antigen expression but also result in different antigen types. This underscores the importance of genetic characterization for clinical studies and exploring genetic diversity within the population. This study primarily aims to genetically characterize the Duffy blood group within three Algerian populations: the Zenata, Reguibat, and Oran populations...

Adjuvants have been essential to malaria vaccine development, but their impact on the vaccine-induced antibody repertoire is poorly understood. Here, we used cDNA sequences from antigen-specific single memory B cells to express 132 recombinant human anti-Pfs230 monoclonal antibodies (mAbs). Alhydrogel®-induced mAbs demonstrated higher binding to Pfs230D1, although functional activity was similar between adjuvants. All Alhydrogel® mAbs using IGHV1-69 gene bound to recombinant Pfs230D1, but none blocked parasite transmission to mosquitoes; similarly, no AS01 mAb using IGHV1-69 blocked transmission...

Blood group antigens, which are prominently expressed in red blood cells, are important in transfusion medicine. The advent of high-throughput genome sequencing technology has facilitated the prediction of blood group antigen phenotypes based on genomic data. In this study, we analyzed data from a large Korean population to provide an updated prevalence of blood group antigen phenotypes, including rare ones. A robust dataset comprising 72,291 single nucleotide polymorphism arrays, 5318 whole-exome sequences, and 4793 whole-genome sequences was extracted from the Korean Genome and Epidemiology Study, Genome Aggregation Database, and Korean Variant Archive and then analyzed...

The Duffy protein, a transmembrane molecule, acts as a receptor for various chemokines and facilitates binding between reticulocytes and the Plasmodium Duffy antigen binding protein. Duffy expression is associated with the Duffy chemokine receptor antigen genotype on chromosome 1 and exhibits variation across different geographic regions. Traditionally, the Duffy negative genotype and phenotype have been described to confer a certain level of protection against infection and symptom development. However, recent data suggest a shift in this behavior, with significantly higher prevalence observed in individuals with Duffy negative genotype or phenotype...

Differences in the distribution of RBC antigens defining the blood group types among different populations have been well established. Fewer studies exist that have explored the blood group profiles of indigenous populations worldwide. With the availability of population-scale genomic datasets, we have explored the blood group profiles of theOrang Aslis, who are the indigenous population in Peninsular Malaysia and provide a systematic comparison of the same with major global population datasets. Variant call files fromwhole genome sequence data (hg19) of 114 Orang Asli were retrieved from The Orang Asli Genome Project...

Despite considerable international heterogeneity in the incidence and histological subtypes of gastric cancer (GC), in addition to more recent epidemiological trends, chemotherapy has long represented the main systemic therapeutic option in its treatment. For the roughly 20% of GC with human epidermal growth factor receptor 2 (HER2) overexpression, there is a more recently established role for the addition of HER2+ based therapy in the form of trastuzumab. However, while immune checkpoint inhibitors (ICIs) have revolutionised the treatment of other malignancies including melanoma and renal cell carcinoma over the past decade, they have only gained a foothold in GC in more recent years...

Plasmodium vivax malaria affects 14 million people each year. Its invasion requires interactions between the parasitic Duffy-binding protein ( Pv DBP) and the N-terminal extracellular domain (ECD1) of the host's Duffy antigen/receptor for chemokines (DARC). ECD1 is highly flexible and intrinsically disordered, therefore it can adopt different conformations. We computationally modeled the challenging ECD1 local structure. With T-REMD simulations, we sampled its dynamic behavior and collected its most representative conformations...

BACKGROUND AND OBJECTIVES: For 5 years, routine genotyping has been performed for selected blood groups of blood donors in the Copenhagen Capital Region, Denmark. The result is summarized in the following. MATERIALS AND METHODS: Genotyping was carried out by an external service provider using the competitive allele specific PCR (KASP) technology. The genotypes were returned to the blood bank and translated into phenotypes by a proprietary IT application. RESULTS: In total, 65 alleles from 16 blood group systems (ABO, MNS, Rh, Lutheran, Kell, Duffy, Kidd, Diego, Yt, Dombrock, Colton, Landsteiner-Wiener, Cromer, Knops, Vel, secretor status) and the HPA1, HPA5 and HPA15 antigens were interrogated...

UNLABELLED: Infection with Mycobacterium tuberculosis (MTB) remains one of the most important opportunistic infections in people with HIV-1 (PWH). While it is well accepted that active Tuberculosis (TB) leads to rapid progression of immunodeficiency in PWH, the interaction between MTB and HIV-1 during the asymptomatic phase of both infections remains poorly understood. Here, we show in a well-matched cohort of PWH with suppressed HIV-1 viral load that MTB infection is associated with a baseline transcriptional profile away from a Type 1 Interferon towards a proinflammatory cytokine response...

The invasion of reticulocytes by Plasmodium vivax merozoites is dependent on the interaction of the Plasmodium vivax Duffy Binding Protein (PvDBP) with the Duffy antigen receptor for chemokines (DARC). The N-terminal cysteine-rich region II of PvDBP (PvDBPII), which binds DARC, is a leading P. vivax malaria vaccine candidate. Here, we have evaluated the immunogenicity of recombinant PvDBPII formulated with the adjuvants Matrix-M and GLA-SE in mice. Analysis of the antibody responses revealed comparable ELISA recognition titres as well as similar recognition of native PvDBP in P...

BACKGROUND: Infections with Plasmodium ovale are widely distributed but rarely investigated, and the resulting burden of disease has been underestimated. Plasmodium ovale curtisi Duffy binding protein domain region II (PocDBP-RII) is an essential ligand for reticulocyte recognition and host cell invasion by P. ovale curtisi. However, the genomic variation, antigenicity and immunogenicity of PocDBP-RII remain major knowledge gaps. METHODS: A total of 93 P. ovale curtisi samples were collected from migrant workers who returned to China from 17 countries in Africa between 2012 and 2016...