Role of Cellular Heparan Sulfate Proteoglycans in Infection of Human Adenovirus Serotype 3 and 35

Abstract

Species B human adenoviruses (Ads) are increasingly associated with outbreaks of acute respiratory disease in U.S. military personnel and civil population. The initial interaction of Ads with cellular attachment receptors on host cells is via Ad fiber knob protein. Our previous studies showed that one species B Ad receptor is the complement receptor CD46 that is used by serotypes 11, 16, 21, 35, and 50 but not by serotypes 3, 7, and 14. In this study, we attempted to identify yet-unknown species B cellular receptors. For this purpose we used recombinant Ad3 and Ad35 fiber knobs in high-throughput receptor screening methods including mass spectrometry analysis and glycan arrays. Surprisingly, we found that the main interacting surface molecules of Ad3 fiber knob are cellular heparan sulfate proteoglycans (HSPGs). We subsequently found that HSPGs acted as low-affinity co-receptors for Ad3 but did not represent the main receptor of this serotype. Our study also revealed a new CD46-independent infection pathway of Ad35. This Ad35 infection mechanism is mediated by cellular HSPGs. The interaction of Ad35 with HSPGs is not via fiber knob, whereas Ad3 interacts with HSPGs via fiber knob. Both Ad3 and Ad35 interacted specifically with the sulfated regions within HSPGs that have also been implicated in binding physiologic ligands. In conclusion, our findings show that Ad3 and Ad35 directly utilize HSPGs as co-receptors for infection. Our data suggest that adenoviruses evolved to simulate the presence of physiologic HSPG ligands in order to increase infection.

Macropinocytotic Uptake and Infection of Human Epithelial Cells with Species B2 Adenovirus Type 35

“…Unlike Ad2/5, Ad35 uses macropinocytosis as an infectious uptake pathway. It requires CD46, integrins, PKC, a sodium/proton exchanger, actin, Rac1, Pak1, and CtBP1 but not heparan sulfate, which had been suggested to be involved in virus attachment to Chinese hamster ovary cells (98). These results mirror the infectious pathway into epithelial cells for the species B1 Ad3 (3).…”

Symmetry-Related Clustering of Positive Charges Is a Common Mechanism for Heparan Sulfate Binding in Enteroviruses

“…Several viruses are known to interact with HSPG molecules at the cell surface as a prelude to infection, and the list of such viruses continues to grow (8,31,50). These include some serotypes of adenovirus which can show differential preference over the various conformations of HSPG that can occur (46). Several picornaviruses, including members of different species of the genus Enterovirus, have been reported to interact with HSPG (12,19,28,29,47,49).…”

Oncolytic adenovirus based on serotype 3

“…However, this receptor has been proposed to be expressed to high degree in tumor cells. 15,17,[21][22][23][24][25]44 Also, Figure 5 In vivo Ad5 neutralising antibody experiment. A nonreplicative Ad5 (GL) virus was injected subcutaneously on days 0, 3 and 6 into immunocompetent NMRI mice.…”

“…Some candidate receptors for adenovirus 3 have been proposed, but these findings have been disputed in other publications and therefore the cellular entry of Ad3 remains poorly understood. [17][18][19][20] Nevertheless, it has been possible to show that the receptor(s) most relevant for Ad3 are highly expressed in many cancer cell types 15,17,[21][22][23][24][25] in contrast to the Ad5 receptor CAR, which may be frequently downregulated in advanced tumors. 13,23,[26][27][28] Wild-type Ad3 causes mainly respiratory infections and conjuctivitis in humans.…”