Biology subjects

Dwivedi, G.

Publications and source records attributed to Dwivedi, G..

4 recordsLinked to original sources

bioRxiv2025

The type I IFN-IL-27 axis promotes mRNA vaccine-induced CD8+ T cell responses

The ability of lipid nanoparticle (LNP)-delivered mRNA vaccines to induce type I IFNs is critical to promote CD8+ T cell responses. The studies presented here indicate that immunization with nucleoside modified mRNA-LNP vaccines drives myeloid cell expression of the cytokine IL-27, which acts on antigen-specific CD8+ T cells to sustain T cell expansion. In vitro and in vivo studies revealed that type I IFN signaling is necessary for mRNA-LNP-induced IL-27 production, that immunization failed in IL-27 KO mice, and that immunization of IFNAR1-deficient mice with mRNA-LNP particles that also encode IL-27 mRNA restored antigen-specific CD8+ T cell responses. In addition, IL-27 mRNA-LNPs served as an adjuvant that improved cytolytic CD8+ T cell responses and the therapeutic efficacy of mRNA-LNPs to drive anti-pathogen and anti-tumor immunity. These studies highlight the central role of IL-27 in mRNA-LNP induced CD8+ T cell responses and the ability of this cytokine to augment the functionality of the CD8+ T cell response for prophylactic or therapeutic immunization.

immunology↗

bioRxiv2024

An IL-12 mRNA-LNP adjuvant enhances mRNA-LNP vaccine induced CD8+ T cell responses

The design of vaccines that induce CD8+ T cell responses has historically been a challenge, but the development of viral vectors or lipid nanoparticles (LNPs) to deliver mRNA that encode for target antigens provide more effective strategies to generate protective CD8+ T cell memory. Because interleukin-12 (IL-12) supports CD8+ T cell expansion and acquisition of effector functions, studies were performed to assess its contribution to the ability of an mRNA vaccine to promote CD8+ T cell responses. In vitro and in vivo, mRNA-LNPs did not stimulate myeloid cell production of IL-12, and the CD8+ T cell response to vaccination with the model antigen ovalbumin (OVA) was IL-12 independent. However, co-administration of IL-12 mRNA-LNPs with OVA mRNA-LNPs enhanced OVA-specific CD8+ T cell expansion, improved acquisition of effector function and resulted in an expanded memory CD8+ T cell pool. These heightened responses were associated with improved protective responses against Listeria monocytogenes-OVA and B16 FO-OVA melanoma. Thus, modification of mRNA vaccine formulations by inclusion of a cytokine mRNA provides a strategy to enhance CD8+ T cell mediated protection.

immunology↗

bioRxiv2024

Chromosome-level genome assembly of autotetraploid Selenicereus megalanthus and gaining genomic insights into the evolution of trait patterning in diploid and polyploid pitaya species

Yellow pitaya (Selenicereus megalanthus, 2n=4x=44) breeding remains severely hindered due to lacking a reference genome. Here we report yellow pitayas high-quality chromosome-level genome assembly and link the phenotypic trait with genomic data, based on Hi-C, ATAC, and RNA-seq data of specific tissues. We declared yellow pitaya as an autotetraploid with a 7.16 Gb genome size (harboring 27,246 high confidence genes) and majorly evolved from diploid ancestors, which remains unknown. Beyond generating the genome assembly, we explored the 3D chromatin organization which revealed insights into the genome, compartments A (648 and 519), compartments B (728 and 1064), topologically associated domains-TADs (3376 and 2031), and varying numbers of structural variations (SVs) in diploid and polyploid pitaya species, respectively. Overall, TAD boundaries were enriched with the motifs of AP2, WRKY18/60/75, MYB63/116, PHL2, and GATA8 in both pitaya species. By linking the open chromatin genomic structure to function, we identified the major changes in betalains biosynthesis pathway in diploid and polyploid pitaya. Moreover, the higher genetic expression of SmeADH1 [Chr11, Compartment A (135400000 - 135500000), genes inside the TAD region (135480000 - 135520000)], and lower expression of HuDOPA [Chr11, Compartment A (87100000 - 87200000), genes inside the TAD region (87160000-87200000)] acts as a key regulator of yellow and red color on the pericarp of polyploid and diploid pitaya, respectively. In addition, higher expression of HuCYP76AD1 genes in diploid pitaya and lower expression of SmeCYP76AD1 in polyploid pitaya potentially created the difference in the oxidase process that led to the production of betacyanin and betaxanthin, respectively. Furthermore, our results revealed not only the type of motifs that play a potential role in trait patterning but we also further uncovered that motif count in TAD-boundaries may impact the gene expression within the TAD regions of diploid and polyploid pitaya. Our valuable genomic resource and comparison of 3D euchromatin architecture of diploid and polyploid pitaya species will not only aid in the advancement of molecular breeding efforts but also offer insights into the organization of genomes, SVs, compartmentalization (A and B), and TADs, which have the potential to strengthen the idea of TADs-based trait improvement to achieve global food security.

plant biology↗

bioRxiv2022

A multiple comorbidities mouse model to assess atherosclerosis progression following lung infection in ApoE deficient mice

BackgroundInflammation is a risk factor for atherosclerosis progression. Hospitalisation for pneumonia is associated with increased risk of cardiovascular disease. Herein, we describe a multiple comorbidities murine model to study the impact of bacterial pneumonia on atherosclerosis. MethodsFirstly, a minimal infectious dose of Streptococcus pneumoniae (TIGR4 strain) to produce clinical pneumonia with a low mortality rate (20%) was established. C57Bl/6 ApoE-/- mice were fed a high-fat diet prior to administering intranasally 105 colony forming units of TIGR4 or phosphate buffered saline (PBS). At days 2, 7 and 28 post inoculation (PI), the lungs of mice were imaged by MRI and PET. Mice were euthanised and investigated for changes in systemic inflammation and changes in lung morphology using ELISA, Luminex assay and real-time PCR. ResultsTIGR4 inoculated mice presented with varying degreess of lung infiltrate, pleural effusion and consolidation on MRI at all timepoints up to 28 days PI. Moreover, PET scans identified significantly higher FDG uptake in the lungs of TIGR4 inoculated mice up to 28 days PI. Majority (90%) TIGR4-inoculated mice developed pneumococcal-specific IgG antibody response at 28 days PI. Consistent with these observations, TIGR4 inoculated mice displayed significantly increased inflammatory gene expression (IL-1{beta} & IL6) in the lungs and significantly increased levels of circulating inflammatory protein (CCL3) at 7- and 28-days PI respectively. ConclusionsOur mouse model presents a discovery tool to understand the link between acute infections, including pneumonia, and increased cardiovascular disease risk in humans with inflammation as the mechanistic catalyst. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=138 SRC="FIGDIR/small/485412v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@e76491org.highwire.dtl.DTLVardef@17b712eorg.highwire.dtl.DTLVardef@143b2f4org.highwire.dtl.DTLVardef@199dbe1_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗