Selection of specific interactors from phage display library based on sea lamprey variable lymphocyte receptor sequences.

Variable lymphocyte receptors (VLRs) are non-immunoglobulin components of adaptive immunity in jawless vertebrates. These proteins composed of leucine-rich repeat modules offer some advantages over antibodies in target binding and therefore are attractive candidates for biotechnological applications. In this paper we report the design and characterization of a phage display library based on a previously proposed dVLR scaffold containing six LRR modules [Wezner-Ptasinska et al., 2011]. Our library was designed based on a consensus approach in which the randomization scheme reflects the frequencies of amino acids naturally occurring in respective positions responsible for antigen recognition. We demonstrate general applicability of the scaffold by selecting dVLRs specific for lysozyme and S100A7 protein with KD values in the micromolar range. The dVLR library could be used as a convenient alternative to antibodies for effective isolation of high affinity binders.

Ammocoetes of Pacific Lamprey are not susceptible to common fish rhabdoviruses of the U.S. Pacific northwest.

Pacific Lampreys Entosphenus tridentatus have experienced severe population declines in recent years and efforts to develop captive rearing programs are under consideration. However, there is limited knowledge of their life history, ecology, and potential to harbor or transmit pathogens that may cause infectious disease. As a measure of the possible risks associated with introducing wild lampreys into existing fish culture facilities, larval lampreys (ammocoetes) were tested for susceptibility to infection and mortality caused by experimental exposures to the fish rhabdovirus pathogens: infectious hematopoietic necrosis virus (IHNV) and viral haemorrhagic septicaemia virus (VHSV). Two IHNV isolates, representing the U and M genogroups, and one VHSV isolate from the IVa genotype were each delivered to groups of ammocoetes by immersion at moderate and high viral doses, and by intraperitoneal injection. Ammocoetes were then held in triplicate tanks with no substrate or sediment. During 41 d of observation postchallenge there was low or no mortality in all groups, and no virus was detected in the small number of fish that died. Ammocoetes sampled for incidence of infection at 6 and 12 d after immersion challenges also had no detectable virus, and no virus was detected in surviving fish from any group. A small number of ammocoetes sampled 6 d after the injection challenge had detectable virus, but at levels below the original quantity of virus injected. Overall there was no evidence of infection, replication, or persistence of any of the viruses in any of the treatment groups. Our results suggest that Pacific Lampreys are highly unlikely to serve as hosts that maintain or transmit these viruses.

Viral haemorrhagic septicaemia virus (VHSV) genotype II isolated from European river lamprey Lampetra fluviatilis in Finland during surveillance from 1999 to 2008.

We examined the occurrence of viral haemorrhagic septicaemia virus (VHSV) in the main spawning stocks of wild European river lamprey Lampetra fluviatilis in the rivers of Finland from 1999 to 2008. Pooled samples of internal organs (kidney, liver and heart or brain) from 2621 lampreys were examined for the presence of VHSV by standard virological techniques. VHSV was isolated from 5 samples from the rivers Lestijoki and Kalajoki, which flow from Finland into the Bothnian Bay of the Baltic Sea. The presence of VHSV was confirmed by immunofluorescent antibody technique (IFAT), ELISA and RT-PCR. Phylogenetic analysis based on the full-length VHSV glycoprotein (G) gene sequence revealed that the isolates were most closely related to the VHSV strain isolated in 1996 from herring Clupea harengus and sprat Sprattus sprattus in the Eastern Gotland Basin of the Baltic Sea, and were therefore assigned to VHSV genotype II. The partial G gene sequences obtained (nt 1 to 672-1129) of all 5 lamprey VHSV isolates were identical, and so were the entire G genes (nt 1 to 1524) of 2 isolates sequenced. The virulence of one of the lamprey isolates was evaluated by an experimental infection trial in rainbow trout Oncorhynchus mykiss fry. No mortality was induced postinfection by waterborne and intraperitoneal challenge, respectively, while 2 genotype Id isolates originating from Finnish rainbow trout caused marked mortality under the same conditions. The infection in the European river lamprey is thought to be independent from the epidemic in farmed rainbow trout in Finnish brackish waters, because the isolates from rainbow trout were of a different genotype. This is the first report of VHSV found in the European river lamprey. The role of wild river lampreys in maintaining the infection in the marine environment remains unclear.