Metabolic and mitochondria alterations induced by SARS-CoV-2 accessory proteins ORF3a, ORF9b, ORF9c and ORF10 (preprint)

Antiviral signaling, immune response and cell metabolism in human body are dysregulated by SARS-CoV-2, the causative agent of the COVID-19. Here, we show that SARS-CoV-2 accessory proteins ORF3a, ORF9b, ORF9c and ORF10 induce a significant mitochondrial and metabolic reprogramming in A549 lung epithelial cells. While all four ORFs caused mitochondrial fragmentation and altered mitochondrial function, only ORF3a and ORF9c induced a marked structural alteration in mitochondrial cristae. ORF9b, ORF9c and ORF10 induced largely overlapping transcriptomes. In contrast, ORF3a induced a distinct transcriptome, including the downregulation of numerous genes for proteins with critical mitochondrial functions and morphology. Genome-Scale Metabolic Models predicted common and private metabolic flux reprogramming, notably a depressed amino acid metabolism, and an enhanced metabolism of specific lipids distinctly induced by ORF3a. These findings reveal metabolic dependencies and vulnerabilities prompted by SARS-CoV-2 accessory proteins that may be exploited to identify new targets for intervention.

COVID-19-Related Temporary Disability in Healthcare Workers in Spain during the Four First Pandemic Waves (preprint)

Healthcare workers (HCW) have been the professional category most exposed to SARS-CoV-2. The pandemic’s impact on HCW was analyzed in terms of COVID-19-related temporary disability (TD) between February 15 2020 and May 1 2021. TDs in HCW for COVID-19 infection or quarantine were described. TD quarantine/infection ratios and TDs per 100,000 affiliated HCW were compared with the cumulative incidence (CI) of COVID-19 cases notified to the National Network of Epidemiological Surveillance. TDs rates by economic activity and occupation were computed. A total of 429,127 TDs were recorded, 36,6% for infection. Three-quarters (76%) were women. The median TD quarantine/infection ratio was 2.5 (Interquartile range [IQR] 1.5-3.9). TDs rates in HCW were always above the CI except for the last two months of the fourth wave. Hospital activities accounted for 84% of TDs and showed the highest TD rate for infection (8,279/100,000). The highest TDs rates were registered among Nursing assistants, Nursing professionals and Physicians: 7,426, 6,925 and 5,508/100,000, respectively. The results demonstrate the high impact of COVID-19 on HCW in Spain and it’s inequalities. They also confirm that TDs represent a complementary source of information for epidemiological and public health surveillance and could provide an early warning of new emerging infections.

Unbiased spectral cytometry immunome characterization predicts COVID-19 mRNA vaccine failure in older adults and patients with lymphoid malignancies. (preprint)

COVID-19 affects the population unequally with a higher impact on aged and immunosuppressed people. Hence, we assessed the effect of SARS-CoV-2 vaccination in immune compromised patients (older adults and oncohematologic patients), compared with healthy counterparts. While the acquired humoral and cellular memory did not predict subsequent infection 18 months after full immunization, spectral and computational cytometry revealed several subsets within the CD8+ T-cells, B-cells, NK cells, monocytes and CD45RA+CCR7- T{gamma}{delta} cells differentially expressed in further infected and non-infected individuals not just following immunization, but also prior to that. Of note up to 7 subsets were found within the CD45RA+CCR7- T{gamma}{delta} population with some of them being expanded and other decreased in subsequently infected individuals. Moreover, some of these subsets also predicted COVID-induced hospitalization in oncohematologic patients. Therefore, we hereby have identified several cellular subsets that, even before vaccination, strongly related to COVID-19 vulnerability as opposed to the acquisition of cellular and/or humoral memory following vaccination with SARS-CoV-2 mRNA vaccines.

SARS-CoV-2 accessory proteins involvement in inflammatory and profibrotic processes through IL11 signaling (preprint)

SARS-CoV-2, the cause of the COVID19 pandemic, possesses eleven accessory proteins encoded in its genome. Their roles during infection are still not completely understood. Transcriptomic analysis revealed that both WNT5A and IL11 were significantly up-regulated in A549 cells expressing individual accessory proteins ORF6, ORF8, ORF9b or ORF9c from SARS-CoV-2 (Wuhan-Hu-1 isolate). IL11 signaling-related genes were also differentially expressed. Bioinformatics analysis disclosed that both WNT5A and IL11 were involved in pulmonary fibrosis idiopathic disease. Functional assays confirmed their association with profibrotic cell responses. Subsequently, data comparison with lung cell lines infected with SARS-CoV-2 or lung biopsies from patients with COVID19 evidenced altered gene expression that matched those obtained in this study. Our results show ORF6, ORF8, ORF9b and ORF9c involvement in inflammatory and profibrotic responses. Thus, these accessory proteins could be targeted by new therapies against COVID19 disease.

Antiviral immune responses, cellular metabolism and adhesion are differentially modulated by SARS-CoV-2 ORF7a or ORF7b (preprint)

SARS-CoV-2, the causative agent of the present COVID-19 pandemic, possesses eleven accessory proteins encoded in its genome, and some have been implicated in facilitating infection and pathogenesis through their interaction with cellular components. Among these proteins, accessory protein ORF7a and ORF7b functions are poorly understood. In this study, A549 cells were transduced to express ORF7a and ORF7b, respectively, to explore more in depth the role of each accessory protein in the pathological manifestation leading to COVID-19. Bioinformatic analysis and integration of transcriptome results identified defined canonical pathways and functional groupings revealing that after expression of ORF7a or ORF7b, the lung cells are potentially altered to create conditions more favorable for SARS-CoV-2, by inhibiting the IFN-I response, increasing proinflammatory cytokines release, and altering cell metabolic activity and adhesion. Based on these results, it is reasonable to suggest that ORF7a and ORF7b could be targeted by new therapies or used as future biomarkers during this pandemic.

Moral Force: Leaders' Actions and Social Distancing (preprint)

In the context of the COVID-19 pandemic, leaders' actions can influence whether individuals stay at home or ignore social distancing orders. Mexican president López Obrador held public events in different states of the country during the health emergency. This paper studies whether his example of contravening social distancing recommendations increases mobility rates. Using mobility data from UNDP-GRANDATA and a generalized event study design, we find that AMLO's public appearances increased mobility rates in the municipalities of the states he visited in the days following the events. Furthermore, using electoral data from the 2018 presidential election, we also find that mobility rates increase in municipalities where his political support is high after the president's events. We find that media coverage is the primary mechanism driving our results. Lastly, in the pandemic's advanced stages, the president's example does not affect mobility. The results suggest that leaders' actions are relevant to influence decisions when individuals have limited information.