Biology subjects

Hadadianpour, A.

Publications and source records attributed to Hadadianpour, A..

5 recordsLinked to original sources

bioRxiv2025

Evaluating the practical aspects and performance of commercial single-cell RNA sequencing technologies

The rapid development of updated and new commercially available single-cell transcriptomics platforms provides users with a range of experimental options. Cost, sensitivity, throughput, flexibility, and ease of use, all influence the selection of an optimal workflow. We performed a comprehensive comparison of single-cell transcriptomic approaches using multiple standardized PBMCs from different donors. We report on standard single-cell metrics including cell recovery, sequencing efficiency, sensitivity, cell annotation, and differential gene expression for seven recently available kits that interrogate whole transcriptome mRNA, and two that include TCR profiling. We also discuss workflow throughput, sample requirements, timing, cost, and labor as critical factors to consider. In addition to variable experimental constraints imposed by each platform, our findings highlight differences in cell recovery and sensitivity, which we found to significantly influence the ability to resolve cell subtypes. This work provides a basis by which users can balance performance and practical considerations when selecting a single-cell RNA sequencing platform.

genomics↗

bioRxiv2024

Cell Simulation as Cell Segmentation

Single-cell spatial transcriptomics promises a highly detailed view of a cells transcriptional state and microenvironment, yet inaccurate cell segmentation can render this data murky by misattributing large numbers of transcripts to nearby cells or conjuring nonexistent cells. We adopt methods from ab initio cell simulation to rapidly infer morphologically plausible cell boundaries that preserve cell type heterogeneity. Benchmarking applied to datasets generated by three commercial platforms show superior performance and computational efficiency of this approach compared with existing methods. We show that improved accuracy in cell segmentation aids greatly in detection of difficult to accurately segment tumor infiltrating immune cells such as neutrophils and T cells. Lastly, through improvements in our ability to delineate subsets of tumor infiltrating T cells, we show that CXCL13-expressing CD8+ T cells tend to be more closely associated with tumor cells than their CXCL13-negative counterparts in data generated from renal cell carcinoma patient samples.

bioinformatics↗

bioRxiv2023

snPATHO-seq: unlocking the pathology archives

Formalin-fixed paraffin-embedded (FFPE) samples are valuable but underutilized in single-cell omics research due to their low DNA and RNA quality. In this study, leveraging recent single-cell genomic technology advances, we introduce a versatile method to derive high-quality single-nucleus transcriptomic data from FFPE samples.

molecular biology↗

bioRxiv2023

Identification and Characterization of a Novel Nematode Pan Allergen (NPA) from Wuchereria bancrofti and their Potential Role in Human Filarial Tropical Pulmonary Eosinophilia (TPE)

Tropical pulmonary eosinophilia (TPE) is a chronic respiratory syndrome associated with Lymphatic Filariasis (LF), a tropical parasitic infection of the human, transmitted by mosquitoes. A larval form of LF, the microfilariae trapped in the lungs of TPE subjects have a major role in initiating the TPE syndrome. To date, there are no reports on the potential allergen that is responsible for generating parasite-specific IgE in TPE. In this project, we screened a cDNA expression library of the microfilarial stages of Wuchereria bancrofti with monoclonal IgE antibodies prepared from subjects with clinical filarial infections. Our studies identified a novel molecule that showed significant sequence similarity to an allergen. A blast analysis showed the presence of similar proteins in a number of nematodes parasites. Thus, we named the molecule as Nematode Pan Allergen (NPA). Subsequent functional analysis showed that NPA is a potent allergen that can cause release of histamine from mast cells, induce secretion of proinflammatory cytokines from alveolar macrophages and promote accumulation of eosinophils, all of which occur in TPE lungs. Therefore, we believe that NPA may have a significant role in the pathology of the TPE syndrome.

microbiology↗

bioRxiv2019

Selectivity and engineering of the sialoglycan-binding spectrum in Siglec-like adhesins

The Siglec-like Serine-Rich Repeat (SRR) adhesins mediate bacterial attachment to mammalian hosts via sialoglycan receptors. Here, we combine structural, computational, biochemical, and phylogenetic approaches to elucidate the determinants of the sialoglycan-binding spectrum across the family of Siglec-like SRR adhesins. We further identified mutable positions that disproportionately affect sialoglycan selectivity, as demonstrated by increases in binding to alternative ligands of 2- to 3-orders of magnitude. Biologically, these studies highlight how bacteria nimbly modulate the receptor interaction during coevolution of host and pathogen. These studies additionally created binding proteins specific for sialyl-T antigen or 6S-sialyl LewisX that can recognize glycosylation of human plasma proteins. The engineered binding proteins can facilitate the characterization of normal cellular glycan modifications or may be used as diagnostic tools in disease states with altered glycosylation.\n\nSignificanceThe ability of bacteria to bind selectively to host receptors underlies both commensalism and pathogenesis. Here, we identify the molecular basis for receptor selectivity in streptococci that bind to sialoglycan receptors. This revealed how to convert these adhesins into selective probes that measure triand tetrasacharides within the context of larger glycosylations. These probes that can be used in a laboratory with no specialized equipment and can be used to address biological questions relating to sialoglycan-dependent signaling and adhesion.

biochemistry↗