Ex VivoandIn VivoCD46 Receptor Utilization by Species D Human Adenovirus Serotype 26 (HAdV26)

Abstract

Human adenovirus serotype 26 (Ad26) is used as a gene-based vaccine against SARS-CoV-2 and HIV-1. Yet, its primary receptor portfolio remains controversial, potentially including sialic acid, CAR, integrins, and CD46. We and others have shown that Ad26 can use CD46, but these observations were questioned by the inability to co-crystallize Ad26 fiber with CD46. Recent work demonstrated that Ad26 binds CD46 with its hexon protein rather than its fiber. We examined the functional consequences of Ad26 for infection in vitro and in vivo. Ectopic expression of human CD46 on Chinese hamster ovary cells increased Ad26 infection significantly. Deletion of the complement control protein domains CCP1 or CCP2 or the serine-threonine-proline (STP) region of CD46 reduced infection. Comparing wild type and sialic acid-deficient CHO cells, we show that the usage of CD46 is independent of its sialylation status. Ad26 transduction was increased in CD46 transgenic mice after intramuscular (IM) injection, but not after intranasal (IN) administration. Ad26 transduction was 10-fold lower than Ad5 after intratumoral (IT) injection of CD46-expressing tumors. Ad26 transduction of liver was 1000-fold lower than Ad5 after intravenous (IV) injection. These data demonstrate the use of CD46 by Ad26 under certain situations, but also show that the receptor has little consequence by other routes of administration. Finally, IV injection of high doses of Ad26 into CD46 mice induced release of liver enzymes in the bloodstream and reduced white blood cell counts, but did not induce thrombocytopenia. This suggests that Ad26 virions do not induce direct clotting side effects seen during COVID-19 vaccination with this serotype of adenovirus. IMPORTANCE Human species D Ad26 is being pursued as a low seroprevalence vector for oncolytic virotherapy and gene-based vaccination against HIV-1 and SARS-CoV-2. However, there is debate in the literature about its tropism and receptor utilization, which directly influence its efficiency for certain applications. This work was aimed at determining which receptor(s) this virus uses for infection, and its role in virus biology, vaccine efficacy, and importantly, in vaccine safety.

Refined Capsid Structure of Human Adenovirus D26 at 3.4 Å Resolution

“…In contrast, Ad26 does not bind FX [11], and it is, therefore, more severely targeted by natural antibodies and complement and destruction by Kupffer cells [38]. The effect of this interaction is profound, as evinced by our recent observation that Ad5 mediates 1000-fold higher transduction of the liver than Ad26 after intravenous injections in CD46 transgenic mice [39].…”

Oncolytic Adenoviruses Armed with Co-Stimulatory Molecules for Cancer Treatment

“…It represents more than 70% of all known human adenovirus types [ 12 , 56 ]. The wild-type HAdV-D is associated with ocular infections, but the spectrum of diseases caused by this type of virus is still unclear [ 11 , 57 ]. Infections with HAdV-D occur more often in patients with compromised immune systems, such as those with HIV [ 42 ].…”

Adenovirus entry: Stability, uncoating, and nuclear import

“…The importance of fiber knob binding to receptors was first demonstrated with coxsackievirus AdV receptor (CAR), a high affinity attachment factor for most HAdVs, including canine AdV‐2 (CAdV‐2) and avian AdV CELO (Soudais et al, 2000 ), but not for the B, D, and G types (Bergelson et al, 1997 ; Freimuth et al, 1999 ; Kirby et al, 2000 ; Roelvink et al, 1998 ; Tomko et al, 1997 ). Species B and D use CD46 (Cupelli et al, 2010 ; Fleischli et al, 2005 , 2007 ; Gaggar et al, 2003 ; Gustafsson et al, 2010 ; Pache et al, 2008 ; Persson et al, 2009 ; Russell, 2004 ; Sakurai et al, 2006 , 2007 ; Sirena et al, 2004 , 2005 ; Tuve et al, 2006 ; Wang, Li, Yumul, et al, 2011 ; Wang, Yumul, et al, 2013 ) or desmoglein (DSG)‐2 (Hemsath et al, 2022 ; Trinh et al, 2012 ; Vassal‐Stermann et al, 2019 ; Wang et al, 2015 ; Wang, Li, Liu, et al, 2011 ; Wang, Li, Yumul, et al, 2011 ; Wang, Yumul, et al, 2013 ). AdV‐D26 has been reported to use CD46 or sialic acid as a receptor through fiber knob or hexon as ligands (Baker, Mundy, et al, 2019 ; Hemsath et al, 2022 ; Persson et al, 2021 ).…”

“…Species B and D use CD46 (Cupelli et al, 2010 ; Fleischli et al, 2005 , 2007 ; Gaggar et al, 2003 ; Gustafsson et al, 2010 ; Pache et al, 2008 ; Persson et al, 2009 ; Russell, 2004 ; Sakurai et al, 2006 , 2007 ; Sirena et al, 2004 , 2005 ; Tuve et al, 2006 ; Wang, Li, Yumul, et al, 2011 ; Wang, Yumul, et al, 2013 ) or desmoglein (DSG)‐2 (Hemsath et al, 2022 ; Trinh et al, 2012 ; Vassal‐Stermann et al, 2019 ; Wang et al, 2015 ; Wang, Li, Liu, et al, 2011 ; Wang, Li, Yumul, et al, 2011 ; Wang, Yumul, et al, 2013 ). AdV‐D26 has been reported to use CD46 or sialic acid as a receptor through fiber knob or hexon as ligands (Baker, Mundy, et al, 2019 ; Hemsath et al, 2022 ; Persson et al, 2021 ).…”