During infection with dengue viruses (DENVs), the lipid landscape within host cells is significantly altered to assemble membrane platforms that support viral replication and particle assembly. Fatty acyl-CoAs are key intermediates in the biosynthesis of complex lipids that form these membranes. They also function as key signaling lipids in the cell. Here, we carried out loss of function studies on acyl-CoA thioesterases (ACOTs), a family of enzymes that hydrolyze fatty acyl-CoAs to free fatty acids and coenzyme A, to understand their influence on the lifecycle of DENVs. The loss of function of the type I ACOTs 1 (cytoplasmic) and 2 (mitochondrial) together significantly increased DENV serotype 2 (DENV2) viral replication and infectious particle release. However, isolated knockdown of mitochondrial ACOT2 significantly decreased DENV2 protein translation, genome replication, and infectious virus release. Furthermore, loss of ACOT7 function, a mitochondrial type II ACOT, similarly suppressed DENV2. As ACOT1 and ACOT2 are splice variants, these data suggest that functional differences and substrate specificities due to the location (cytosol and mitochondria, respectively) of these proteins may account for the differences in DENV2 infection phenotype. Additionally, loss of mitochondrial ACOT2 and ACOT7 expression also altered the expression of several ACOTs located in multiple organelle compartments within the cell, highlighting a complex relationship between ACOTs in the DENV2 virus lifecycle.

Importance: Pregnant women are at increased risk of severe COVID-19, but the contribution of viral RNA load, the presence of infectious virus, and mucosal antibody responses remain understudied. Objective: To evaluate the association of COVID-19 outcomes following confirmed infection with vaccination status, mucosal antibody responses, infectious virus recovery and viral RNA levels in pregnant compared with non-pregnant women. Design: A retrospective observational cohort study of remnant clinical specimens from SARS-CoV-2 infected patients between October 2020-May 2022. Setting: Five acute care hospitals within the Johns Hopkins Health System (JHHS) in the Baltimore, MD-Washington, DC area. Participants: Participants included confirmed SARS-CoV-2 infected pregnant women and matched non-pregnant women (matching criteria included age, race/ethnicity, and vaccination status). Exposure: SARS-CoV-2 infection, with documentation of SARS-CoV-2 mRNA vaccination. Main Outcome(s): The primary dependent measures were clinical COVID-19 outcomes, infectious virus recovery, viral RNA levels, and mucosal anti-spike (S) IgG titers from upper respiratory tract samples. Clinical outcomes were compared using odds ratios (OR), and measures of virus and antibody were compared using either Fisher’s exact test, two-way ANOVA, or regression analyses. Results were stratified according to pregnancy, vaccination status, maternal age, trimester of pregnancy, and infecting SARS-CoV-2 variant. Results(s): A total of 452 individuals (117 pregnant and 335 non-pregnant) were included in the study, with both vaccinated and unvaccinated individuals represented. Pregnant women were at increased risk of hospitalization (OR = 4.2; CI = 2.0-8.6), ICU admittance, (OR = 4.5; CI = 1.2-14.2), and of being placed on supplemental oxygen therapy (OR = 3.1; CI =1.3-6.9). An age-associated decrease in anti-S IgG titer and corresponding increase in viral RNA levels ( P < 0.001) was observed in vaccinated pregnant, but not non-pregnant, women. Individuals in their 3 ^rd trimester had higher anti-S IgG titers and lower viral RNA levels ( P < 0.05) than those in their 1 ^st or 2 ^nd trimesters. Pregnant individuals experiencing breakthrough infections due to the omicron variant had reduced anti-S IgG compared to non-pregnant women ( P < 0.05). Conclusions and Relevance: In this cohort study, vaccination status, maternal age, trimester of pregnancy, and infecting SARS-CoV-2 variant were each identified as drivers of differences in mucosal anti-S IgG responses in pregnant compared with non-pregnant women. Observed increased severity of COVID-19 and reduced mucosal antibody responses particularly among pregnant participants infected with the Omicron variant suggest that maintaining high levels of SARS-CoV-2 immunity may be important for protection of this at-risk population. Key Points: Question: Is greater COVID-19 disease severity during pregnancy associated with either reduced mucosal antibody responses to SARS-CoV-2 or increased viral RNA levels? Finding: In a retrospective cohort of pregnant and non-pregnant women with confirmed SARS-CoV-2 infection, we observed that (1) disease severity, including ICU admission, was greater among pregnant than non-pregnant women; (2) vaccination was associated with reduced recovery of infectious virus in non-pregnant women but not in pregnant women; (3) increased nasopharyngeal viral RNA levels were associated with reduced mucosal IgG antibody responses in pregnant women; and (4) greater maternal age was associated with reduced mucosal IgG responses and increased viral RNA levels, especially among women infected with the Omicron variant. Meaning: The findings of this study provide novel evidence that, during pregnancy, lower mucosal antibody responses are associated with reduced control of SARS-CoV-2, including variants of concern, and greater disease severity, especially with increasing maternal age. Reduced mucosal antibody responses among vaccinated pregnant women highlight the need for bivalent booster doses during pregnancy.

Nestled within the Rocky Mountain National Forest, 114 scientists and students gathered at Colorado State University’s Mountain Campus for this year’s 21st annual Rocky Mountain National Virology Association meeting. This 3-day retreat consisted of 31 talks and 30 poster presentations discussing advances in research pertaining to viral and prion diseases. The keynote address provided a timely discussion on zoonotic coronaviruses, lessons learned, and the path forward towards predicting, preparing, and preventing future viral disease outbreaks. Other invited speakers discussed advances in SARS-CoV-2 surveillance, molecular interactions involved in flavivirus genome assembly, evaluation of ethnomedicines for their efficacy against infectious diseases, multi-omic analyses to define risk factors associated with long COVID, the role that interferon lambda plays in control of viral pathogenesis, cell-fusion-dependent pathogenesis of varicella zoster virus, and advances in the development of a vaccine platform against prion diseases. On behalf of the Rocky Mountain Virology Association, this report summarizes select presentations.

Due to the COVID-19 pandemic and multiple devastating forest fires, the 2020 meeting of the Rocky Mountain Virology Association was held virtually. The three-day gathering featured talks describing recent advances in virology and prion research. The keynote presentation described the measles virus paradox of immune suppression and life-long immunity. Special invited speakers presented information concerning visualizing antiviral effector cell biology in mucosal tissues, uncovering the T-cell tropism of Epstein-Barr virus type 2, a history and current survey of coronavirus spike proteins, a summary of Zika virus vaccination and immunity, the innate immune response to flavivirus infections, a discussion concerning prion disease as it relates to multiple system atrophy, and clues for discussing virology with the non-virologist. On behalf of the Rocky Mountain Virology Association, this report summarizes selected presentations.

This autumn, approximately 100 scientists and students from the Rocky Mountain area along with invited speakers attended the 18th annual meeting of the Rocky Mountain Virology Association that was held at the Colorado State University Mountain Campus. The two-day gathering featured 31 talks and 33 posters all of which focused on specific areas of current virology and prion protein research. Since the keynote presentation focused on the oligoadenylate synthetase-ribonuclease L pathway the main area of focus was on host–virus interactions, however other areas of interest included virus vectors, current models of virus infections, prevention and treatment of virus infections, separate sessions on RNA viruses and prion proteins, and a special talk highlighting various attributes of targeted next-generation sequencing. The meeting was held at the peak of the fall Aspen colors surrounded by five mountains >11000 ft (3.3 km) where the secluded campus provided the ideal setting for extended discussions and outdoor exercise. On behalf of the Rocky Mountain Virology Association, this report summarizes 42 selected presentations.

This autumn, 95 scientists and students from the Rocky Mountain area, along with invited speakers from Colorado, California, Montana, Florida, Louisiana, New York, Maryland, and India, attended the 19th annual meeting of the Rocky Mountain Virology Association that was held at the Colorado State University Mountain Campus located in the Rocky Mountains. The two-day gathering featured 30 talks and 13 posters—all of which focused on specific areas of current virology and prion protein research. The keynote presentation reviewed new tools for microbial discovery and diagnostics. This timely discussion described the opportunities new investigators have to expand the field of microbiology into chronic and acute diseases, the pitfalls of sensitive molecular methods for pathogen discovery, and ways in which microbiology help us understand disruptions in the social fabric that pose pandemic threats at least as real as Ebola or influenza. Other areas of interest included host factors that influence virus replication, in-depth analysis of virus transcription and its effect on host gene expression, and multiple discussions of virus pathology, epidemiology as well as new avenues of diagnosis and treatment. The meeting was held at the peak of fall Aspen colors, surrounded by five mountains >11,000 ft (3.3 km), where the secluded campus provided the ideal setting for extended discussions, outdoor exercise and stargazing. On behalf of the Rocky Mountain Virology Association, this report summarizes 43 selected presentations.