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Biology subjects

Ratnasiri, K.

Publications and source records attributed to Ratnasiri, K..

3 recordsLinked to original sources

Systems immunology of transcriptional responses to viral infection identifies conserved antiviral pathways across macaques and humans

Viral pandemics and epidemics pose a significant global threat, with emerging and re-emerging viruses responsible for four pandemics in the 21st century alone. While macaques have been utilized as a model for understanding viral disease in a controlled setting, it remains unclear how conserved the antiviral responses to diverse viruses are between macaques and humans. To address this critical knowledge gap, we conducted a comprehensive cross-species analysis of transcriptomic data from over 6000 blood samples from macaques and humans infected with one of 31 viruses, including Lassa, Ebola, Marburg, Zika, and dengue. Our findings demonstrate that irrespective of primate or viral species, there are conserved antiviral responses which are consistent regardless of infection phase (acute, chronic, or latent) and viral genome type (DNA or RNA viruses). Moreover, by leveraging longitudinal data from experimental challenges, we identified virus-specific response dynamics such as host responses to Coronaviridae and Orthomyxoviridae infections peaking 1-3 days earlier than responses to Filoviridae and Arenaviridae viral infections. Additionally, through comparative analysis of immune responses across viruses, we identified a unique enrichment of lymphoid cellular response modules in macaque Flaviviridae infection that persists in human responses to dengue. Our results underscore macaque studies as a powerful tool for gaining new insights into viral pathogenesis and immune responses that translate to humans, which can inform viral therapeutic development and enable pandemic preparedness. One sentence summaryUsing longitudinal macaque viral challenge studies, we identified shared and virus-specific responses to infection that replicate in human viral disease - thereby demonstrating the utility of macaque models of viral infection to understand antiviral biology and for pandemic preparedness.

immunology↗

SARS-CoV-2 infects human adipose tissue and elicits an inflammatory response consistent with severe COVID-19

The COVID-19 pandemic, caused by the viral pathogen SARS-CoV-2, has taken the lives of millions of individuals around the world. Obesity is associated with adverse COVID-19 outcomes, but the underlying mechanism is unknown. In this report, we demonstrate that human adipose tissue from multiple depots is permissive to SARS-CoV-2 infection and that infection elicits an inflammatory response, including the secretion of known inflammatory mediators of severe COVID-19. We identify two cellular targets of SARS-CoV-2 infection in adipose tissue: mature adipocytes and adipose tissue macrophages. Adipose tissue macrophage infection is largely restricted to a highly inflammatory subpopulation of macrophages, present at baseline, that is further activated in response to SARS-CoV-2 infection. Preadipocytes, while not infected, adopt a proinflammatory phenotype. We further demonstrate that SARS-CoV-2 RNA is detectable in adipocytes in COVID-19 autopsy cases and is associated with an inflammatory infiltrate. Collectively, our findings indicate that adipose tissue supports SARS-CoV-2 infection and pathogenic inflammation and may explain the link between obesity and severe COVID-19. One sentence summaryOur work provides the first in vivo evidence of SARS-CoV-2 infection in human adipose tissue and describes the associated inflammation.

immunology↗

Quantitative reverse transcription PCR assay to detect pyrethroid resistance in Culex mosquitoes

Pyrethroid insecticides are widely used to control mosquitoes that transmit diseases such as West Nile virus (WNV) to humans. A single nucleotide polymorphism (SNP) in the knockdown resistance locus (kdr) of the voltage gated sodium channel (Vgsc) gene of Culex mosquitoes confers knockdown resistance to pyrethroids. PCR-based assays that detect these SNPs in Culex species are currently available for Culex pipiens Linnaeus and Culex quinquefasciatus Say. RNAseq was employed to sequence the coding region of Vgsc for Culex tarsalis Coquillett and Culex erythrothorax Dyar, two WNV vectors. We utilized the cDNA sequence to develop a quantitative reverse transcriptase PCR assay that detects the L1014F mutation in the kdr of Vgsc. Because this locus is conserved, the assay successfully detected the SNPs in multiple Culex spp. vectors of WNV in the United States. The resulting Culex RTkdr assay was validated using quantitative PCR, CDC bottle bioassays, and sequencing of PCR products. Using sequencing, we determined the accuracy of the Culex RTkdr assay was 99%. Pyrethroid resistance was more common among Cx. pipiens than other Culex spp. and co-occured with agriculture. We anticipate that public health and vector control agencies may utilize the Culex RTkdr assay to map the distribution of pyrethroid resistance in Culex species to more efficiently control mosquitoes and the diseases they transmit.

ecology↗