Antibodies that inhibit Plasmodium falciparum invasion of erythrocytes are believed to be an important component immunity against malaria. During blood-stage infection, P. can use different pathways for erythrocyte by varying the expression and/or utilization members 2 ligand families: erythrocyte-binding antigens (EBAs) and reticulocyte-binding homologs (PfRhs). Invasion broadly classified into groups based on sialic acid (SA) surface parasite ligands. We found inhibitory antibodies...

The present study was performed to investigate how blockade of the l ‐arginine/nitric oxide (NO) pathway influences function lower urinary tract in vivo , as studied by cystometry conscious rats and vitro isolated muscle preparations from rat detrusor urethra. ‐N G ‐nitro arginine methyl ester ( ‐NAME), 10 20 mg kg −1 administered intra‐arterially, decreased micturition volume bladder capacity, increased spontaneous contractions. d ‐NAME (20 ) had no effect. No changes urodynamic parameters...

Abstract Antibodies against P . falciparum merozoites fix complement to inhibit blood-stage replication in naturally-acquired and vaccine-induced immunity; however, specific targets of these functional antibodies their importance protective immunity are unknown. Among malaria-exposed individuals, we show that complement-fixing more strongly correlated with than growth quantified using the current reference assay for merozoite vaccine evaluation. We identify antigen-specific associated...

ABSTRACT Antibodies that inhibit replication of Plasmodium falciparum in erythrocytes are thought to be important both acquired immunity malaria and as mediators generated by candidate blood-stage vaccines. However, several constraints have limited the study these functional antibodies population studies vaccine trials. We report development optimization high-throughput growth inhibition assays with improved sensitivity use minimal volumes test serum. The major inhibitory activity serum from...

Background Antibodies that inhibit the growth of blood-stage Plasmodium falciparum may play an important role in acquired and vaccine-induced immunity humans. However, acquisition activity these antibodies is not well understood. Methods We tested dialysed serum purified immunoglobulins from Kenyan children adults for inhibition P. vitro using different parasite lines. Serum were measured by ELISA to antigens, extracted schizonts, recombinant merozoite surface protein 1 (42 kDa C-terminal...

Humoral immunity is important in limiting clinical disease malaria, yet the longitudinal B cell response to infection remains unclear. We performed a 1-year prospective study patients treated for acute P. falciparum malaria first time, or with previous exposure disease. Using an unbiased exploratory approach mass cytometry, followed by targeted flow we found that ~80% of mature cells proliferated expressed CD11c. Only ~40% CD11c+ displayed atypical phenotype, remaining primarily made up...

Points• Partnerships between universities in high-and low-income countries have the potential to increase research capacity both settings.• We describe a partnership Karolinska Institutet Sweden and Makerere University Uganda that includes joint PhD degree program sharing of scientific ideas resources.• Ten years

Abstract Abs that inhibit Plasmodium falciparum invasion of erythrocytes form an important component human immunity against malaria, but key target Ags are largely unknown. Phenotypic variation by P. mediates the evasion inhibitory Abs, contributing to capacity cause repeat and chronic infections. However, involved in mediating immune have not been defined, studies function limited. In this study, we used novel approaches determine importance erythrocyte-binding (EBAs), which ligands, as...

Background Malaria kills almost 1 million people every year, but the mechanisms behind protective immunity against disease are still largely unknown. Methodology/Principal Findings In this study, surface plasmon resonance technology was used to evaluate affinity (measured as kd) of naturally acquired antibodies Plasmodium falciparum antigens MSP2 and AMA1. Antibodies in serum samples from residents endemic areas bound with higher affinities AMA1 than MSP2, 3D7 allele MSP2-3D7 FC27 allele....

Background Malaria remains a significant health burden, particularly in Uganda, which has one of the highest incidence rates globally. Rapid diagnostic tests (RDTs) are widely used for malaria diagnosis due to their ease use and affordability resource-limited settings. However, false-positive RDT results may lead unnecessary antimalarial treatments missed diagnoses other febrile conditions. This study aimed evaluate accuracy compared microscopy loop-mediated isothermal amplification (LAMP)...

Introduction Antibodies targeting the blood-stage of Plasmodium falciparum play a critical role in naturally acquired immunity to malaria by limiting parasitemia. One mode action antibodies is direct inhibition merozoite invasion erythrocytes through ligands. However, evasion inhibitory may be mediated P. switching between various ligand-mediated pathways. Here, we investigated potential roles ligands PfRH1, PfRH2a and PfRH2b immune phenotypic variation, their importance as targets human...

Stable B cell lines producing human monoclonal antibodies to Chlamydia were established from salpingitis patients in the early convalescence phase. The antibody-producing cells immortalized by Epstein Barr virus (EBV) transformation. Specific antibody-secreting clones enriched a stepwise microtiter plate cloning procedure. selected showed stable antibody production for more than 1 yr continuous culture. Serologic specificity was demonstrated micro-immunofluorescence (micro-IF) tests against...

To be able to robustly propagate P. falciparum at optimal conditions in vitro is of fundamental importance for genotypic and phenotypic studies both established fresh clinical isolates. Cryo-preserved isolates from Ugandan children with severe or uncomplicated malaria were investigated parasite phenotypes under different growth studied directly the peripheral blood. The cultures showed a minimal loss parasite-mass preserved percentage multiple infected pRBCs that blood, maintained adhesive...

Abstract Antibodies play a key role in acquired human immunity to Plasmodium falciparum (Pf) malaria and target merozoites reduce or prevent blood-stage replication the development of disease. Merozoites present complex array antigens immune system, currently, there is only partial understanding targets protective antibodies how responses different are boosted. We hypothesized that would be differences rate acquisition well they boosted by infection, which impacts immunity. examined range...

In northern Europe, tick-borne diseases such as Lyme borreliosis (LB) and encephalitis (TBE) are well known. The actual incidence of Babesia infections, however, has remained elusive. this study, the prevalence antibodies against two spp. was investigated in a cohort patients that were seropositive for Borrelia (B.) burgdorferi sensu lato (s.l.). Data compared to control group healthy individuals. Sera collected from 283 individuals residing southernmost region Sweden, Skåne County. Almost...

During pregnancy, specific variants of Plasmodium falciparum-infected erythrocytes (IEs) can accumulate in the placenta through adhesion to chondroitin sulfate A (CSA) mediated by expression PfEMP1 encoded var2csa-type genes. Antibodies against these are associated with protection from maternal malaria. We evaluated antibodies among Kenyan, Papua New Guinean, and Malawian men Kenyan children two different CSA-binding P. falciparum isolates expressing var2csa variants. Specific IgG was...

Abstract Background Today only indirect fluorescent antibody assays (IFAs) are commercially available to detect antibodies against Babesia divergens in humans. IFA is subjective and requires highly experienced staff. We have therefore developed an enzyme-linked immunosorbent assay (ELISA)–based method for measuring anti–B. immunoglobulin G human blood samples. Methods Crude merozoite extract from vitro cultures of a new B. isolate was used ELISA different sets samples: Borrelia...

Aim and objectives The aim of this study was to describe dialogic strategies about health lifestyle used by primary healthcare nurses ( PHN s) in the Västerbotten Intervention Programme VIP ) Sweden. Background offers all citizens aged 40, 50 60 County an individual check‐up followed a health‐promoting dialogue with specialist PHN. Inconsistencies previous reports effects counselling promotion suggest that it is important dialogues understand highlight aspects improving their effects. Method...

Severe babesiosis with 9.8% parasitemia was diagnosed in a patient the Netherlands who had previously undergone splenectomy. We confirmed Babesia venatorum using PCR and sequencing. B. also most prevalent species Ixodes ricinus ticks collected around patient's home. Our findings warrant awareness for severe similar patients.

Plasmodium falciparum infected red blood cells (iRBC) express variant surface antigens (VSA) of which VAR2CSA is involved in placental sequestration and causes pregnancy-associated malaria (PAM). Primigravidae are most susceptible to PAM whereas antibodies associated with protection often present at higher levels multigravid women. However, HIV co-infection has been shown alter this parity-dependent acquisition immunity, more severe symptoms as well episodes positive women versus negative a...

Plasmodium falciparum EBA175 and PfRh2 belong to two main families involved in parasite invasion, both are potential vaccine candidates. Current knowledge is limited regarding which target antigens subclasses of antibodies actually important for protection, how naturally acquired immunity achieved. Repeated blood samples were collected from individuals Nigeria over a period almost one year. ELISA was used analyse IgG responses. For (region III-V) (a fragment of) PfRh2, the dominant antibody...

Abstract Understanding the functional characteristics of naturally acquired antibodies against P. falciparum merozoite antigens is crucial for determining protective functions antibodies. Affinity (measured as k d ) two key targets immunity, EBA175 and PfRh2, was determined using Surface Plasmon Resonance (SPR) in a longitudinal survey Nigeria. A majority participants, 79% 67%, maintained stable antibody affinities to respectively, over time. In about 10% individuals, there reciprocal...

Plasmodium falciparum's ability to invade erythrocytes is essential for its survival within the human host. Immune mechanisms that impair this are therefore expected contribute immunity against parasite. Plasma of humans who naturally exposed malaria has been shown have growth-inhibitory activity (GIA) in vitro. However, importance GIA relation protection from unclear. In a case-control study nested longitudinally followed population Tanzania, plasma samples collected at baseline 171...