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USGS · 70043686

Resistance and Protective Immunity in Redfish Lake Sockeye Salmon Exposed to M Type Infectious Hematopoietic Necrosis Virus (IHNV)

Gael Kurath·Kyle Garver·Maureen K. Purcell·Scott E. LaPatra
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Abstract

Differential virulence of infectious hematopoietic necrosis virus (IHNV) isolates from the U and M phylogenetic subgroups is clearly evident in the Redfish Lake (RFL) strain of sockeye salmon Oncorhynchus nerka. In these fish, experimental immersion challenges with U isolates cause extremely high mortality and M isolates cause low or no mortality. When survivors of M virus immersion challenges were exposed to a secondary challenge with virulent U type virus they experienced high mortality, indicating that the primary M challenge did not elicit protective immunity. Delivery of a moderate dose (2 × 104 plaque-forming units [PFU]/fish) of virus by intraperitoneal injection challenge did not overcome RFL sockeye salmon resistance to M type IHNV. Injection challenge with a high dose (5 × 106 PFU/fish) of M type virus caused 10% mortality, and in this case survivors did develop protective immunity against a secondary U type virus challenge. Thus, although it is possible for M type IHNV to elicit cross-protective immunity in this disease model, it does not develop after immersion challenge despite entry, transient replication of M virus to low levels, stimulation of innate immune genes, and development of neutralizing antibodies in some fish.

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Gael Kurath, Kyle Garver, Maureen K. Purcell, Scott E. LaPatra. 2010-06-01. Resistance and Protective Immunity in Redfish Lake Sockeye Salmon Exposed to M Type Infectious Hematopoietic Necrosis Virus (IHNV). https://doi.org/10.1577/h09-050.1

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