Biology subjects

Prabhala, P.

Publications and source records attributed to Prabhala, P..

5 recordsLinked to original sources

bioRxiv2025

Transcriptional Roadmap of the Human Airway Epithelium Identifying HLF as a Novel Regulator of Basal Stem Cell Function

RationaleThe human airway epithelium depends on a coordinated hierarchy of stem-and differentiated cells to maintain tissue integrity and respond to injury. Defining the transcriptional and translational programs that govern these processes is critical for understanding airway disease and advancing regenerative therapies. ObjectivesTo map the transcriptional landscape of the human airway epithelium and identify regulatory factors controlling basal stem cell function and epithelial differentiation. MethodsWe performed single-cell RNA sequencing on bronchial biopsies from nine healthy never-smokers, categorized into young (<40 years) and aged (>60 years) cohorts. Unbiased cell type annotation and pseudotime trajectory analysis were used to define cell states and transcription factor dynamics. Measurements and Main ResultsAll major airway epithelial cell types were identified, with conserved composition and transcriptional programs across age groups. Basal stem cells (BSCs) exhibited elevated ribosomal gene expression, indicating increased translational readiness. Pseudotime analysis revealed transitions from basal to differentiated states, with MYC, JUN, and FOS upregulated in proliferative suprabasal cells. HLF emerged as a BSC-enriched transcription factor downregulated upon differentiation. Functional assays showed that HLF overexpression suppresses proliferation in airway BSC and in lung squamous carcinoma cells, while Hlf-deficient mice display basal cell hyperplasia and deficient differentiation. In lung cancer datasets, low HLF expression correlated with worse patient survival. ConclusionsThis study defines conserved gene programs in the human airway epithelium and identifies HLF as a novel regulator of BSC proliferation and potential tumor suppressor. These findings may inform the development of regenerative therapies and contribute to improved understanding and treatment of lung disease.

molecular biology↗

bioRxiv2025

Ex vivo recapitulation of intramuscular mRNA vaccination with naive and recall antigens using a human Lymphoid Follicle Chip platform

Predicting the efficacy and toxicity of intramuscular mRNA vaccines remains challenging. Here, we describe an ex vivo human cell-based model that replicates immune responses to lipid nanoparticle (LNP)-based mRNA vaccines that require intramuscular injection. Vaccines are administered into a biomimetic muscle module containing human skeletal myoblasts and antigen-presenting cells (APCs) to mimic intramuscular vaccination, followed by transfer of the APCs and soluble factors to a microfluidic human lymphoid follicle chip (LF Chip) to mimic lymphatic drainage. Non-replicating mRNA vaccines directly induce antigen expression in APCs, whereas self-amplifying mRNA vaccines require muscle cell-APC contact within the intramuscular vaccination module. Transfer of APCs and soluble factors to the LF Chip induces LF expansion, de novo antigen-specific IgG production against a naive antigen (rabies virus glycoprotein), and cytokine release, with responses varying depending on LNP type. Vaccination of LF chips against SARS- COV-2 Spike recall antigen using the Moderna Spikevax vaccine generates neutralizing antibodies and induces somatic hypermutation. This biomimetic platform offers an all-human alternative for evaluating vaccine-induced immunity, potentially obviating the need for non-human primates and accelerating vaccine development.

immunology↗

bioRxiv2023

Maternal sterol 27-hydroxylase is crucial for securing fetal development

The maternal body helps in providing nutrients and degrading toxic metabolites instead of the fetal body; disruptions in these mechanisms affect normal fetal development. Sterol 27-hydroxylase (Cyp27a1) is involved in the alternative pathway of bile acid synthesis, which is enhanced during pregnancy. However, its role in fetal development remains unclear. Here, we demonstrate that maternal Cyp27a1 activity is essential for progression of normal pregnancy and fetal organ formation. Depletion of maternal Cyp27a1 reduced the pregnancy rate and litter size. Newborn mice died of respiratory distress syndrome resulting from the absence of mature alveolar epithelial cells. These phenotypes were caused by 7-hydroxycholesterol (7-HC) accumulating in Cyp27a1-deficient mice. Mechanistically, 7-HC destabilized the Fau protein, mediating ribosome assembly, the downregulation of which caused poor polysome formation, lower protein synthesis, and impaired lung maturation. Overall, this study revealed an essential mechanism of securing fetal development by degrading a toxic metabolite in the maternal body.

developmental biology↗

bioRxiv2021

Enteric coronavirus infection and treatment modeled with an immunocompetent human intestine-on-a-chip

Many patients infected with coronaviruses, such as SARS-CoV-2 and NL63 that use ACE2 receptors to infect cells, exhibit gastrointestinal symptoms and viral proteins are found in the human gastrointestinal tract, yet little is known about the inflammatory and pathological effects of coronavirus infection on the human intestine. Here, we used a human intestine-on-a-chip (Intestine Chip) microfluidic culture device lined by patient organoid-derived intestinal epithelium interfaced with human vascular endothelium to study host cellular and inflammatory responses to infection with NL63 coronavirus. These organoid-derived intestinal epithelial cells dramatically increased their ACE2 protein levels when cultured under flow in the presence of peristalsis-like mechanical deformations in the Intestine Chips compared to when cultured statically as organoids or in Transwell inserts. Infection of the intestinal epithelium with NL63 on-chip led to inflammation of the endothelium as demonstrated by loss of barrier function, increased cytokine production, and recruitment of circulating peripheral blood mononuclear cells (PMBCs). Treatment of NL63 infected chips with the approved protease inhibitor drug, nafamostat, inhibited viral entry and resulted in a reduction in both viral load and cytokine secretion, whereas remdesivir, one of the few drugs approved for COVID19 patients, was not found to be effective and it also was toxic to the endothelium. This model of intestinal infection was also used to test the effects of other drugs that have been proposed for potential repurposing against SARS-CoV-2. Taken together, these data suggest that the human Intestine Chip might be useful as a human preclinical model for studying coronavirus related pathology as well as for testing of potential anti-viral or anti-inflammatory therapeutics.

bioengineering↗

bioRxiv2019

Lymph node follicle formation and vaccination responses reconstituted in vitro in a human Organ Chip

Lymphoid follicles (LFs) are responsible for generation of adaptive immune responses in secondary lymphoid organs and form ectopically during chronic inflammation. A human model of LF formation would provide a tool to understand LF development and an alternative to non-human primate models for preclinical evaluation of vaccines. Here, we show that primary human blood B- and T-lymphocytes autonomously assemble into ectopic LFs when cultured in a three-dimensional (3D) extracellular matrix gel within an organ-on-a-chip microfluidic device. Dynamic fluid flow is required for LF formation and prevention of lymphocyte autoactivation. These germinal center-like LFs contain B cells expressing Activation-Induced Cytidine Deaminase and exhibit plasma cell (PC) differentiation upon activation. To explore their utility for vaccine testing, autologous monocyte-derived dendritic cells were integrated into LF Chips. The human LF chips demonstrated improved antibody responses to split virion influenza vaccination compared to 2D cultures, which were enhanced by addition of a squalene-in-water emulsion adjuvant, and this was accompanied by increases in LF size and number. When inoculated with commercial influenza vaccine, PC formation and production of anti-hemagglutinin IgG were observed, as well as secretion of cytokines similar to those observed in vaccinated humans over clinically relevant timescales.

immunology↗