pseudotyped viruses. A pseudotyped virus is a viral particle bearing other viral en-

velopes or host cell proteins. Accordingly, generation of pseudotyped VSV with a

heterologous viral envelope can be achieved (Figure 11.2). The rVSV gene encoding

VSV.G is replaced with a reporter transgene; for example, enhanced green fluorescent

protein (EGFP). The heterologous viral envelope protein is expressed in the host cells

via an expression plasmid before infection with rVSV-∆G. The rVSV-ΔG virions can

finally encode EGFP with a heterologous viral envelope (Figure 11.3). Such pseu-

dotyped viruses have been used in identifying novel viral receptors, understanding the

FIGURE 11.2 (a) Construction of rVSV-∆G pseudotyped with a heterologous viral en-

velope. (b) Construction of replication-competent rVSV expressing a heterologous viral

envelope.

FIGURE 11.3 (a) Schematic diagram of the production of pseudotyped VSV. (b) Schematic

diagram of the production of recombinant VSV.

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Bioprocessing of Viral Vaccines