Biology subjects

Wines, B. D.

Publications and source records attributed to Wines, B. D..

4 recordsLinked to original sources

bioRxiv2023

Accurate determination of house dust mite sensitization in asthma and allergic rhinitis through cytometric detection of Der p 1 and Der p 2 binding on Basophils (CytoBas)

BackgroundHouse dust mite (HDM) is the commonest allergen trigger globally for allergic rhinitis and atopic asthma. To expedite accurate confirmation of allergen sensitization, we designed fluorescent allergen tetramers to directly stain specific IgE on basophils to detect allergen sensitization using the flow cytometric CytoBas assay. MethodsRecombinant proteins of major HDM allergens (component), Der f 1, Der p 1 and Der p 2 were biotinylated and conjugated with fluorochrome streptavidins as tetramers. Blood samples from 64 HDM-allergic patients and 26 non-HDM-sensitized controls were incubated with allergen tetramers for evaluation of basophil binding (CytoBas) and activation (BAT) with flow cytometry. ResultsThe tetramers effectively bound and activated basophils from allergic patients but not non-sensitized controls. CytoBas with Der p 1 as a single allergen had comparable sensitivity and specificity (92% and 100%) to BAT (91% and 100%), similarly for CytoBas with a single Der p 2 (95% and 96%) to BAT (95% and 87%) in detecting allergen sensitization. A positive staining for Der p 1 and/or Der p 2 was 100% sensitive and 96% specific for HDM allergy. ConclusionsCytoBas has diagnostic accuracy for group 1 and group 2 HDM allergens that is comparable to a BAT assay, but with additional advantages of multiple allergen components in a single tube and no requirement for in vitro basophil activation. These findings endorse a single, multiplex CytoBas assay for accurate and component-resolved diagnosis of aeroallergen sensitization in patients with allergic asthma and/or rhinitis. CAPSULE SUMMARYA single flow cytometry stain of basophils (CytoBas) with both Der p 1 and Der p 2 provides >95% specificity and sensitivity for detection of functional HDM allergen sensitization. HighlightsO_LIFluorescent tetramers of recombinant Der f 1, Der p 1 and Der p 2 can be used to detect functional IgE sensitization to house dust mite (HDM) by flowcytometric detection on basophils (CytoBas). C_LIO_LIA single CytoBas assay with inclusion of both Der p 1 and Der p 2 can detect HDM sensitization with >95% sensitivity and specificity. C_LI

immunology↗

bioRxiv2021

Age dependent changes in circulating Tfh cells influence the development of functional antibodies to malaria in children.

T-follicular helper (Tfh) cells are key drivers of antibodies that protect from malaria. However, little is known regarding the host and parasite factors that influence Tfh and functional antibody development. Here, we use samples from a large cross-sectional study of children residing in an area of high malaria transmission in Uganda to characterize Tfh cells and functional antibodies to multiple parasites stages. We identify a dramatic re-distribution of the Tfh cell compartment with age that is independent of malaria exposure, with Th2-Tfh cells predominating in early childhood, while Th1-Tfh cell gradually increase to adult levels over the first decade of life. Functional antibody acquisition is age-dependent and hierarchical acquired based on parasite stage, with merozoite responses followed by sporozoite and gametocyte antibodies. Antibodies were boosted in children with current infection, and were higher in females. The children with the very highest antibody levels had increased Tfh cell activation and proliferation, consistent with a key role of Tfh cells in antibody development. Together, these data reveal a complex relationship between the circulating Tfh compartment, antibody development and protection from malaria.

immunology↗

bioRxiv2020

Novel virus-like particle vaccine encoding the circumsporozoite protein of Plasmodium falciparum is immunogenic and induces functional antibody responses

RTS,S is the leading malaria vaccine in development, but has demonstrated only moderate protective efficacy in clinical trials. RTS,S is a virus-like particle (VLP) that uses the human hepatitis B virus as scaffold to display the malaria sporozoite antigen, circumsporozoite protein (CSP). Particle formation requires fourfold excess scaffold antigen, and as a result, CSP represents only a small portion of the final vaccine construct. Alternative VLP or nanoparticle platforms that reduce the amount of scaffold antigen and increase the amount of the target CSP antigen present in particles may enhance vaccine immunogenicity and efficacy. Here, we describe the production and characterization of a novel VLP that uses the small surface antigen (dS) of duck hepatitis B virus to display CSP. The CSP-dS fusion protein successfully formed VLPs without the need for excess scaffold antigen, and thus CSP represented a larger portion of the vaccine construct. Importantly, this is the first report of a dS-based vaccine that formed particles without excess scaffold protein. CSP-dS formed large particles approximately 31-74 nm in size and were confirmed to display CSP on the surface. The CSP-dS VLP was highly immunogenic in mice and induced antibodies to multiple regions of CSP, even when administered at a lower vaccine dosage. Vaccine-induced antibodies demonstrated functional activity, including the ability to interact with complement and Fc{gamma}-receptors, both previously identified as important in malaria immunity. Our novel platform to produce VLPs without excess scaffold protein has wide implications for the future development of innovative vaccines for malaria and other infectious diseases.

immunology↗

bioRxiv2019

Multi-functional antibodies are induced by the RTS,S malaria vaccine and associated with protection in a phase I/IIa trial

BackgroundRTS,S is the leading malaria vaccine candidate, but only confers partial efficacy against malaria in children. RTS,S is based on the major Plasmodium falciparum sporozoite surface antigen, circumsporozoite protein (CSP). The induction of anti-CSP antibodies is important for protection, however, it is unclear how protective antibodies function. MethodsWe quantified the induction of functional anti-CSP antibody responses in healthy malaria-naive adults (N=45) vaccinated with RTS,S/AS01. This included the ability to mediate effector functions via the fragment crystallizable (Fc) region, such as interacting with human complement proteins and Fc{gamma}-receptors (Fc{gamma}Rs) that are expressed on immune cells, which promote various immunological functions. ResultsOur major findings were i) RTS,S-induced antibodies mediate Fc-dependent effector functions, ii) functional antibodies were generally highest after the second vaccine dose; iii) functional antibodies targeted multiple regions of CSP, iv) participants with higher levels of functional antibodies had a reduced probability of developing parasitemia following homologous challenge (p<0.05); v) non-protected subjects had higher levels of anti-CSP IgM. ConclusionsOur data suggests a role for Fc-dependent antibody effector functions in RTS,S-induced immunity. Enhancing the induction of these functional activities may be a strategy to improve the protective efficacy of RTS,S or other malaria vaccines.

immunology↗