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. 2000 Jul 5;97(14):8146-50.
doi: 10.1073/pnas.97.14.8146.

Retrograde axonal transport of herpes simplex virus: evidence for a single mechanism and a role for tegument

E L Bearer  1 , X O Breakefield, D Schuback, T S Reese, J H LaVail
Affiliations

Retrograde axonal transport of herpes simplex virus: evidence for a single mechanism and a role for tegument

E L Bearer et al. Proc Natl Acad Sci U S A. .

Abstract

Herpes simplex virus type I (HSV) typically enters peripheral nerve terminals and then travels back along the nerve to reach the neuronal cell body, where it replicates or enters latency. To monitor axoplasmic transport of HSV, we used the giant axon of the squid, Loligo pealei, a well known system for the study of axoplasmic transport. To deliver HSV into the axoplasm, viral particles stripped of their envelopes by detergent were injected into the giant axon, thereby bypassing the infective process. Labeling the viral tegument protein, VP16, with green fluorescent protein allowed viral particles moving inside the axon to be imaged by confocal microscopy. Viral particles moved 2.2 +/- 0.26 micrometer/sec in the retrograde direction, a rate comparable to that of the transport of endogenous organelles and of virus in mammalian neurons in culture. Electron microscopy confirmed that 96% of motile (stripped) viral particles had lost their envelope but retained tegument, and Western blot analysis revealed that these particles had retained protein from capsid but not envelope. We conclude that (i) HSV recruits the squid retrograde transport machinery; (ii) viral tegument and capsid but not envelope are sufficient for this recruitment; and (iii) the giant axon of the squid provides a unique system to dissect the viral components required for transport and to identify the cellular transport mechanisms they recruit.

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Figures

Figure 1
Figure 1
Time lapse sequence of GFP-labeled HSV transported in a living axon. Individual frames of a single microscopic field in a squid axon injected with stripped HSV labeled with VP16-GFP are shown in sequence from left to right (5.3 sec between frames). The stationary particle at the lower right of each frame (arrowhead) serves as reference point for the changes in position of two other particles as they rapidly cross the field on the left of each frame (one of these is indicated by a diagonal arrow). The two moving particles move approximately the same distance between frames, thereby remaining separated from each other by a similar distance. The cell body was toward the top of the page. A live video of this sequence can be accessed at E.L.B.'s web site, http://biomed.brown.edu/faculty/B/Bearer.html. (Bar = 40 μm.)
Figure 2
Figure 2
Herpes viral particles are transported with uniform directionality and velocity along multiple, interweaving tracks in the living axon. (A) Tracings of pathways of 26 particles in a single field of an axon: Tracings were taken from a series of 100 frames captured at 4-sec intervals with a 40× objective and a 5× zoom in a single field from an axon after injection of VP16-GFP-labeled, stripped virus. The cell body was toward the top of the page. Arrowheads indicate the site where an image of each particle was captured in a frame as well as its direction of movement as determined by its location in the subsequent frame. (B) Viral particles move with an average velocity of 2.2 μm/sec. Measurements of the distances moved between frames of 71 particles, all going in the retrograde direction, are summarized in a histogram.
Figure 3
Figure 3
Motile particles are composed of capsid plus a net-like tegument but no envelope. (A) Five images demonstrating the typical structure of stripped virus: a hexagonal capsid with a net-like tegument attached to it, either at one apex or surrounding it. (B and C) Two types of particles predominate in untreated viral preparations: enveloped virus (B) and naked capsid (C). A–C are at the same magnification. (Bar = 100 nm.)
Figure 4
Figure 4
Biochemical analysis of stripped, motile, viral particles. Shown are Coomassie-stained gels and parallel Western blots showing soluble (S) and particulate (P) fractions of viral preparations either untreated (No Tx) or treated (+ Tx) with 0.1% Triton and high salt (see Fig. 1).
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References

    1. Whitley R J. In: Fields Virology. Fields B N, Knipe D M, Howley P M, editors. Philadelphia: Lippencott; 1996. pp. 2297–2336.
    1. Whitley R J, Kimberlin D W, Roizman B. Clin Infect Dis. 1998;26:541–555. - PubMed
    1. Cook M L, Stevens J G. Infect Immun. 1973;7:272–288. - PMC - PubMed
    1. Margolis T, Togni B, LaVail J, Dawson C R. Curr Eye Res. 1987;6:119–126. - PubMed
    1. Topp K S, Meade L B, LaVail J H. J Neurosci. 1994;14:318–325. - PMC - PubMed

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