Biology subjects

Nakka, S. S.

Publications and source records attributed to Nakka, S. S..

2 recordsLinked to original sources

bioRxiv2025

Development of a novel hybrid alphavirus-Nipah virus pseudovirion for rapid quantification of neutralization antibodies

Nipah virus (NiV) is an emergent paramyxovirus that causes serious disease in humans and animals. Accurate quantification of neutralizing antibodies (nAB) against NiV is essential for vaccine development. The current standard, the plaque reduction neutralization test (PRNT), requires authentic infectious NiV and BSL-4 containment, taking 4-7 days to complete. In this study, we developed a hybrid alphavirus-Nipah virus pseudovirion (Ha-NiV) composed of a non-replicating Nipah virus virus-like particle (VLP) that encapsulates an RNA genome from a fast-expressing SFV (Semliki Forest Virus) alphaviral vector. Ha-NiV can infect NiV target cells but is replication incompetent, enabling rapid quantification of nAB (6-18 hours) in BSL-2 conditions. We validated Ha-NiV using sera from Nipah virus-infected African green monkeys and established a good correlation (R2 = 0.86) with PRNT, demonstrating comparable specificity and sensitivity. These results demonstrate that the Ha-NiV assay can serve as a novel platform for convenient and rapid quantification of nAB in BSL-2 settings.

microbiology↗

bioRxiv2020

Single cell BCR and transcriptome analysis after respiratory virus infection reveals spatiotemporal dynamics of antigen-specific B cell responses.

B cell responses are a critical component of anti-viral immunity. However, a comprehensive picture of antigen-specific B cell responses, differentiation, clonal proliferation and dynamics in different organs after infection is lacking. Here, we combined single-cell RNA sequencing with single-cell B cell receptor (BCR) characterization of antigen-specific cells in the draining lymph nodes, spleen and lungs after influenza infection. We identify several novel B cell subpopulations forming after infection and find organ-specific differences that persist over the course of the response. We discover important transcriptional differences between memory cells in lungs and lymphoid organs and describe organ-restricted clonal expansion. Strikingly, by combining BCR mutational analysis, monoclonal antibody expression and affinity measurements we find no differences between germinal center (GC)-derived memory and plasmacells, at odds with an affinity-based selection model. By linking antigen-recognition with transcriptional programming, clonal-proliferation and differentiation, these finding provide important advances in our understanding of antiviral B cell immunity.

immunology↗