Long-term infection passaging of Human Adenovirus 36 in monkey kidney cells

Abstract

Human Adenovirus 36 (HAdV-36) has been related to diverse effects on metabolism and may attenuate the lipid accumulation in kidneys with increased adiposity. Some of these effects would be related to viral persistence. However, until now, a model of persistent in vitro infection by HAdV-36 is unknown. In this study, we examined the cells of the Vero lineage to explore their permissiveness to long-term HAdV-36 infection. HAdV-36 was productively replicated in Vero cells and maintained long-term infection for up to 35 cell passages. A subculture was obtained from the cells that survived the primary infection at a low MOI (0.5). The production of the extracellular infectious virus with titers ranging from 10 4 to 10 6 TCID 50 /mL and DNA-bearing cells was detected. In long-term infected cells, the intracellular distribution of viral antigen was demonstrated by performing immunolocalization (IFI) and expression of cell-viral antigen in 50% of cells by flow cytometry, using anti-HAdV-36 hyperimmune rabbit serum. Furthermore, E1a and E4orf1 genes in long-term infected passages showed a decreasing trend. Our preliminary results reveal that renal epithelial monkey cells are permissive for the productive infection of HAdV-36. Vero cell culture long-term infection might be a promising model for addressing the fundamental aspects of the HAdV-36 biology that cannot reveal broadly-used cultures, which do not maintain longterm infection in primary or transformed cells.

Presence of human adenovirus 36 in visceral fat tissue, viral load, and analysis of its genetic variability

“…Although it has been argued that Ad36 infection is a marker of “low risk” to develop obesity, 10 in the present study, we found this virus to be associated with patients with obesity at a high frequency. In agreement with previous studies, 13–15,21 our results strengthen the need to continue studying the molecular mechanisms involved in infectobesity, particularly the host‒pathogen relationship, in accordance with other authors 39,43 . In light of our results, we consider it important to reconsider whether Ad36 infection is truly a low‐risk factor for developing obesity.…”

“…In agreement with previous studies, [13][14][15]21 our results strengthen the need to continue studying the molecular mechanisms involved in infectobesity, particularly the host-pathogen relationship, in accordance with other authors. 39,43 In light of our results, we consider it important to reconsider whether Ad36 infection is truly a low-risk factor for developing obesity.…”

“…26 In addition, other study in which long-term Ad36 infection in Vero cells was demonstrated, E1a expression was maintained longer and with greater intensity than other early viral genes, making it an interesting study target to explore. 43 The bayesian phylogenetic inference was able to separate and group the different adenoviruses into specific clusters, constituting a potential candidate diagnostic molecular marker to distinguish between different HAdVs in future studies. However, within the Ad36 cluster, no differences between virus sequences from individuals with obesity and normal weight or clinical features were indicated that Ad36 from individuals with obesity has low differentiation and is expanding, 36,37 which is consistent with the phenomenon of increased numbers of people with obesity.…”

“…It has been shown that HAdVs can exhibit a phenomenon of viral persistence in their host, with reactivations that trigger clinical manifestations causing chronic diseases 40–42 . Recently, permissively long‐term infection by Ad36 was reported in Vero cell culture 43 …”

Emerging viral zoonotic diseases: time to address the root causes

“…There have been multiple outbreaks of emerging infections since the turn of the century. A bulk of these diseases is caused by animals, including the Zika virus, Middle East Respiratory Syndrome (MERS), Ebola Virus Disease (EVD), Coronavirus Disease 2019 (COVID-19), Monkeypox (MPOX), and Adenovirus among others (Manirambona et al 2022 ; Alarcon-Valdes et al 2022 ). These diseases were formerly known to infect animals, but they now affect humans.…”