Cell tropism and growth kinetics. (A) Cell tropism and viral titers of ΔIR3 EHV-1 and RacL11 EHV-1 in mouse LM, rabbit RK13, equine NBL-6, simian Vero, and human HeLa cells. Cell monolayers were infected at a moi of 5 moi with ΔIR3 EHV-1 or RacL11 EHV-1, harvested at 72hpi, and titered as described in Materials and Methods. White and gray bars indicate RacL11 EHV-1 and ΔIR3 EHV-1 titers, respectively. (B) Viral growth kinetics of RacL11 EHV-1 and ΔIR3 EHV-1 in RK13 cells infected at a moi of 5. (C) Growth kinetics of RacL11 EHV-1 and ΔIR3 EHV-1 in RK13 cells infected at a moi of 0.1. Cell monolayers were infected with RacL11 EHV-1 or ΔIR3 EHV-1, and aliquots were harvested at designated time points. Virus was titered as described in Materials and Methods. Error bars indicate standard deviations.