Biology subjects

Anabire, N. G.

Publications and source records attributed to Anabire, N. G..

2 recordsLinked to original sources

bioRxiv2022

Extraintestinal survival and host immune response to Vibrio cholerae

Vibrio cholerae is best known to cause the deadly disease cholera. However, in recent years this bacterial pathogen has been found to invade intestinal layers and translocate into the bloodstream of humans. The aim of this study was to investigate the molecular basis of V. cholerae bacteremia. Nine (9) strains of V. cholerae; six (6) environmental strains of non-O1/non-O139 serogroup and three (3) clinical strains of O1 serogroup and El-Tor serotype were screened for survival in serum obtained from immunocompromised patients. Serum from immunocompetent individuals with no known underlying conditions were used as healthy controls. Five (5) environmental strains and one (1) clinical strain of V. cholerae were identified to survive the bactericidal action of serum. Whole genome sequence analysis revealed the cholix toxin (ChxA) and genes encoding for siderophores (FepE and EntD) as possible virulence factors used by the environmental strains to cause invasive bloodstream infection. Peripheral blood mononuclear cells (PBMCs) stimulated with V. cholerae revealed increased expression of some cytokines; IL-1{beta} and IL-13 and the chemokine; RANTES especially among diabetics. The present study illustrates the potential survival of V. cholerae in blood, which could be aided by scavenging for iron from their host leading to severe infections.

microbiology↗

bioRxiv2022

Analysis of allelic cross-reactivity of monoclonal IgG antibodies by a multiplexed reverse FluoroSpot assay

The issue of antibody cross-reactivity is of central importance in immunology, and not least in protective immunity to Plasmodium falciparum malaria, where key antigens show substantial allelic variation (polymorphism). However, serological analysis often does not allow the distinction between true cross-reactivity (one antibody recognizing multiple antigen variants) and apparent cross-reactivity (presence of multiple variant-specific antibodies), as it requires analysis at the single B-cell/monoclonal antibody level. ELISpot is an assay that enables that, and a recently developed multiplexed variant of ELISpot (FluoroSpot) facilitates simultaneous assessment of B-cell/antibody reactivity to several different antigens. In this study, we present a further enhancement of this assay that makes direct analysis of monoclonal antibody-level cross-reactivity with allelic variants feasible. Using VAR2CSA-type PfEMP1 - a notoriously polymorphic antigen involved in the pathogenesis of placental malaria - as a model, we demonstrate the robustness of the assay and its applicability to analysis of true cross-reactivity of monoclonal VAR2CSA-specific antibodies in naturally exposed individuals. The assay is adaptable to the analysis of other polymorphic antigens, rendering it a powerful tool in studies of immunity to malaria and many other diseases.

immunology↗