Recombinant adenoviral (rAd) vectors elicit potent cellular and humoral immune responses and show promise as vaccines for HIV-1, Ebola virus, tuberculosis, malaria, and other infections. These vectors are now widely used and have been generally well tolerated in vaccine and gene therapy clinical trials, with many thousands of people exposed. At the same time, dose-limiting adverse responses have been observed, including transient low-grade fevers and a prior human gene therapy fatality, after systemic high-dose recombinant adenovirus serotype 5 (rAd5) vector administration in a human gene therapy trial. The mechanism responsible for these effects is poorly understood. Here, we define the mechanism by which Ad5 targets immune cells that stimulate adaptive immunity. rAd5 tropism for dendritic cells (DCs) was independent of the coxsackievirus and adenovirus receptor (CAR), its primary receptor or the secondary integrin RGD receptor, and was mediated instead by a heparin-sensitive receptor recognized by a distinct segment of the Ad5 fiber, the shaft. rAd vectors with CAR and RGD mutations did not infect a variety of epithelial and fibroblast cell types but retained their ability to transfect several DC types and stimulated adaptive immune responses in mice. Notably, the pyrogenic response to the administration of rAd5 also localized to the shaft region, suggesting that this interaction elicits both protective immunity and vector-induced fevers. The ability of replication-defective rAd5 viruses to elicit potent immune responses is mediated by a heparin-sensitive receptor that interacts with the Ad5 fiber shaft. Mutant CAR and RGD rAd vectors target several DC and mononuclear subsets and induce both adaptive immunity and toxicity. Understanding of these interactions facilitates the development of vectors that target DCs through alternative receptors that can improve safety while retaining the immunogenicity of rAd vaccines.
Shiver JW, Emini EA (2004) Recent advances in the development of HIV-1 vaccines using replication-incompetent adenovirus vectors. Annu Rev Med 55: 355–372.
Raper SE, Yudkoff M, Chirmule N, Gao GP, Nunes F, et al. (2002) A pilot study of in vivo liver-directed gene transfer with an adenoviral vector in partial ornithine transcarbamylase deficiency. Hum Gene Ther 13: 163–175.
Raper SE, Chirmule N, Lee FS, Wivel NA, Bagg A, et al. (2003) Fatal systemic inflammatory response syndrome in a ornithine transcarbamylase deficient patient following adenoviral gene transfer. Mol Genet Metab 80: 148–158.
Xia D, Henry LJ, Gerard RD, Deisenhofer J (1994) Crystal structure of the receptor-binding domain of adenovirus type 5 fiber protein at 1.7 A resolution. Structure 2: 1259–1270.
Bergelson JM, Cunningham JA, Droguett G, Kurt-Jones EA, Krithivas A, et al. (1997) Isolation of a common receptor for coxsackie B viruses and adenoviruses 2 and 5. Science 275: 1320–1323.
Tomko RP, Xu R, Philipson L (1997) HCAR and MCAR: The human and mouse cellular receptors for subgroup C adenoviruses and group B coxsackieviruses. Proc Natl Acad Sci U S A 94: 3352–3356.
Roelvink PW, Mi LG, Einfeld DA, Kovesdi I, Wickham TJ (1999) Identification of a conserved receptor-binding site on the fiber proteins of CAR-recognizing adenoviridae. Science 286: 1568–1571.
Wickham TJ, Mathias P, Cheresh DA, Nemerow GR (1993) Integrins alpha v beta 3 and alpha v beta 5 promote adenovirus internalization but not virus attachment. Cell 73: 309–319.
Jakubczak JL, Rollence ML, Stewart DA, Jafari JD, Von Seggern DJ, et al. (2001) Adenovirus type 5 viral particles pseudotyped with mutagenized fiber proteins show diminished infectivity of coxsackie B-adenovirus receptor-bearing cells. J Virol 75: 2972–2981.
Einfeld DA, Schroeder R, Roelvink PW, Lizonova A, King CR, et al. (2001) Reducing the native tropism of adenovirus vectors requires removal of both CAR and integrin interactions. J Virol 75: 11284–11291.
Shayakhmetov DM, Li ZY, Ni S, Lieber A (2004) Analysis of adenovirus sequestration in the liver, transduction of hepatic cells, and innate toxicity after injection of fiber-modified vectors. J Virol 78: 5368–5381.
Koizumi N, Kawabata K, Sakurai F, Watanabe Y, Hayakawa T, et al. (2006) Modified adenoviral vectors ablated for coxsackievirus-adenovirus receptor, alphav integrin, and heparan sulfate binding reduce in vivo tissue transduction and toxicity. Hum Gene Ther 17: 264–79.
Mittereder N, March KL, Trapnell BC (1996) Evaluation of the concentration and bioactivity of adenovirus vectors for gene therapy. J Virol 70: 7498–7509.
Shayakhmetov DM, Eberly AM, Li ZY, Lieber A (2005) Deletion of penton RGD motifs affects the efficiency of both the internalization and the endosome escape of viral particles containing adenovirus serotype 5 or 35 fiber knobs. J Virol 79: 1053–1061.
Inaba K, Inaba M, Romani N, Aya H, Deguchi M, et al. (1992) Generation of large numbers of dendritic cells from mouse bone marrow cultures supplemented with granulocyte/macrophage colony-stimulating factor. J Exp Med 176: 1693–1702.
Dechecchi MC, Tamanini A, Bonizzato A, Cabrini G (2000) Heparan sulfate glycosaminoglycans are involved in adenovirus type 5 and 2-host cell interactions. Virology 268: 382–390.
Dechecchi MC, Melotti P, Bonizzato A, Santacatterina M, Chilosi M, et al. (2001) Heparan sulfate glycosaminoglycans are receptors sufficient to mediate the initial binding of adenovirus types 2 and 5. J Virol 75: 8772–8780.
Smith TA, Idamakanti N, Rollence ML, Marshall-Neff J, Kim J, et al. (2003) Adenovirus serotype 5 fiber shaft influences in vivo gene transfer in mice. Hum Gene Ther 14: 777–787.
Holers VM, Kinoshita T, Molina H (1992) The evolution of mouse and human complement C3-binding proteins: Divergence of form but conservation of function. Immunol Today 13: 231–236.
Stevenson SC, Rollence M, Marshall-Neff J, McClelland A (1997) Selective targeting of human cells by a chimeric adenovirus vector containing a modified fiber protein. J Virol 71: 4782–4790.
Bewley MC, Springer K, Zhang YB, Freimuth P, Flanagan JM (1999) Structural analysis of the mechanism of adenovirus binding to its human cellular receptor, CAR. Science 286: 1579–1583.
Kirby I, Davison E, Beavil AJ, Soh CP, Wickham TJ, et al. (1999) Mutations in the DG loop of adenovirus type 5 fiber knob protein abolish high-affinity binding to its cellular receptor CAR. J Virol 73: 9508–9514.
Worgall S, Busch A, Rivara M, Bonnyay D, Leopold PL, et al. (2004) Modification to the capsid of the adenovirus vector that enhances dendritic cell infection and transgene-specific cellular immune responses. J Virol 78: 2572–2580.
Rea D, Schagen FH, Hoeben RC, Mehtali M, Havenga MJ, et al. (1999) Adenoviruses activate human dendritic cells without polarization toward a T-helper type 1-inducing subset. J Virol 73: 10245–10253.
Philpott NJ, Nociari M, Elkon KB, Falck-Pedersen E (2004) Adenovirus-induced maturation of dendritic cells through a PI3 kinase-mediated TNF-alpha induction pathway. Proc Natl Acad Sci U S A 101: 6200–6205.
Miller G, Lahrs S, Shah AB, DeMatteo RP (2003) Optimization of dendritic cell maturation and gene transfer by recombinant adenovirus. Cancer Immunol Immunother 52: 347–358.
Tan PH, Beutelspacher SC, Xue SA, Wang YH, Mitchell P, et al. (2005) Modulation of human dendritic cell function following transduction with viral vectors: Implications for gene therapy. Blood 105: 3824–3832.
Hensley SE, Giles-Davis W, McCoy KC, Weninger W, Ertl HC (2005) Dendritic cell maturation, but not CD8+ T cell induction, is dependent on type I IFN signaling during vaccination with adenovirus vectors. J Immunol 175: 6032–6041.
