Adrenal Gland Infection by Serotype 5 Adenovirus Requires Coagulation Factors

Lucile Tran,Gaétan Cornilleau,Karim Benihoud,Peggy Richard-Fiardo,Jacques Darcourt,Philippe R Franken,Laure-Hélène Ouisse,Georges Vassaux,Knut Stieger

doi:10.1371/journal.pone.0062191

Abstract

Recombinant, replication-deficient serotype 5 adenovirus infects the liver upon in vivo, systemic injection in rodents. This infection requires the binding of factor X to the capsid of this adenovirus. Another organ, the adrenal gland is also infected upon systemic administration of Ad, however, whether this infection is dependent on the cocksackie adenovirus receptor (CAR) or depends on the binding of factor X to the viral capsid remained to be determined. In the present work, we have used a pharmacological agent (warfarin) as well as recombinant adenoviruses lacking the binding site of Factor X to elucidate this mechanism in mice. We demonstrate that, as observed in the liver, adenovirus infection of the adrenal glands in vivo requires Factor X. Considering that the level of transduction of the adrenal glands is well-below that of the liver and that capsid-modified adenoviruses are unlikely to selectively infect the adrenal glands, we have used single-photon emission computed tomography (SPECT) imaging of gene expression to determine whether local virus administration (direct injection in the kidney) could increase gene transfer to the adrenal glands. We demonstrate that direct injection of the virus in the kidney increases gene transfer in the adrenal gland but liver transduction remains important. These observations strongly suggest that serotype 5 adenovirus uses a similar mechanism to infect liver and adrenal gland and that selective transgene expression in the latter is more likely to be achieved through transcriptional targeting.

Highlights

Recombinant, serotype 5 adenoviruses are probably the most widely used delivery vectors in gene therapy
To exclude completely a cocksackie adenovirus receptor (CAR)-dependent mechanism and provide new insight into the infection of the adrenal glands, we compared transgene expression upon injection of a wild-type, replication-deficient adenovirus (AdHwt, 109 PFU) and a replication-deficient adenovirus in which the hexon hypervariable region 5 had been modified (AdH[GA]24, 109 PFU). Both viruses encode the LacZ gene driven by the same promoter and both are able to infect CAR-positive cells [29]. bgalactosidase staining of the whole liver obtained forty-eight hours after systemic AdHwt injection showed an intense blue colour, characteristic of LacZ gene expression (Fig. 1B), while staining of a liver obtained from an AdH[GA]24-injected animal remained unstained (Fig. 1B)
Systemic administration of AdHwt resulted in a very significant increase in b-galactosidase expression compared to untreated controls, while systemic injection of AdH[GA]24 resulted in levels of b-galactosidase transcripts fifty times lower than those obtained with AdHwt (Fig. 1C; P,0.001)

Summary

Introduction

Recombinant, serotype 5 adenoviruses are probably the most widely used delivery vectors in gene therapy. Systemic injection of recombinant adenovirus is followed by a rapid disappearance of the virus from the blood stream [9] and leads to a predominant expression in hepatocytes [10,11,12,13,14]. Another organ efficiently infected by adenoviruses upon systemic injections is the adrenal glands [15,16,17,18,19]. The site of synthesis of cortisol and corticosterone, the zona fasciculata, has been shown to be prone to infection [18]

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Conclusion