Influenza A(H5N8) Virus Similar to Strain in Korea Causing Highly Pathogenic Avian Influenza in Germany

Highly pathogenic avian influenza (H5N8) virus, like the recently described H5N8 strain from Korea, was detected in November 2014 in farmed turkeys and in a healthy common teal (Anas crecca) in northeastern Germany. Infected wild birds possibly introduced this virus.     

Vγ9Vδ2 TCR‐activation by phosphorylated antigens requires butyrophilin 3 A1 (BTN3A1) and additional genes on human chromosome 6

Pyrophosphorylated metabolites of isoprenoid‐biosynthesis (phosphoantigens, PAgs) activate Vγ9Vδ2 T cells during infections and trigger antitumor activity. This activation depends on expression of butyrophilin 3 A1 (BTN3A1) by antigen‐presenting cells. This report defines the minimal genetic requirements for activation of Vγ9Vδ2 T cells by PAgs and mAb 20.1. We compared PAg‐presentation by BTN3A1‐transduced CHO hamster cells with that of CHO cells containing the complete human chromosome 6 (Chr6). BTN3A1 expression alone was sufficient for activation of Vγ9Vδ2 T‐cell receptor transductants by mAb 20.1., while activation by PAgs also required the presence of Chr6. We take this finding as evidence that gene(s) on Chr6 in addition to BTN3A1 are mandatory for PAg‐mediated activation of Vγ9Vδ2 T cells. This observation is important for the design of animal models for PAg‐mediated immune responses and provokes speculations about the analogy between genes controlling PAg presentation and MHC‐localized genes controlling peptide‐antigen presentation.     

Failure of productive infection of Mallards (Anas platyrhynchos) with H16 subtype of avian influenza viruses

Background

Mallard ducks and other waterfowl represent the most important reservoirs of low pathogenic avian influenza viruses (LPAIV). In addition, mallards are the most abundant duck species in Eurasia that migrate over long distances. Despite extended wild bird monitoring studies over the past decade in many Eurasian countries and investigating hundreds of thousands of wild bird samples, no mallard duck was found to be positive for avian influenza virus of subtype H16 in faecal, cloacal or oropharyngeal samples. Just three cases of H16 infections in Anseriformes species were described worldwide. In contrast, H16 viruses have been repeatedly isolated from birds of the Laridae family.

Objective

Here, we tested the hypothesis that mallards are less permissive to infection with H16 viruses.

Methods

Groups of mallard ducks of different age were inoculated via the oculo-nasal-oral route with different infectious doses of an H16N3 AIV.

Results

The ducks did not show any clinical symptoms, and no virus shedding was evident from cloacal and respiratory routes after experimental infection as shown by negative RT-qPCR results. In addition, all serum samples taken on days 8, 21 and 24 post-inoculation were negative by competitive NP-ELISA.

Conclusions

This study provided evidence that mallards are resistant to infection with H16N3 LPAIV.     

Sequence diversity of the haemagglutinin open reading frame of recent highly pathogenic avian influenza H5N1 isolates from Egypt

Archives of Virology - The sequences encoding the haemagglutinin (HA) of twelve H5N1 isolates obtained in 2006 and 2007 from different avian species in backyard holdings and poultry farms in Egypt...     

Butyrophilin 3A (BTN3A,CD277)‐specific antibody 20.1 differentially activates Vγ9Vδ2 TCR clonotypes and interferes with phosphoantigen activation

Phosphoantigens (PAgs)‐like HMBPP ((E)‐4‐hydroxy‐3‐methyl‐but‐2‐enyl diphosphate) and butyrophilin 3 (BTN3A, CD277)‐specific monoclonal antibody 20.1 induce TCR‐mediated activation of Vγ9Vδ2 T cells. Here, we compared murine reporter cells transduced with Vγ9Vδ2 TCRs G115, D1C55, and MOP for the activation in culture with human RAJI cells and PAgs or mAb 20.1 and its single‐chain (sc) derivative. All transductants responded readily to PAg but only TCR MOP γ‐chain‐expressing cells responded to mAb/sc 20.1. Furthermore, both antagonist and agonist mAb and sc of the agonist mAb inhibited the PAg response of TCR‐transduced murine reporter cells. These findings suggest that, in contrast to stimulation by physiological stimulators (PAg), the responsiveness to mAb 20.1 depends strongly on CDR3 sequences of the TCR, and that mAb 20.1 can interfere with the PAg‐response. Mouse or human origin of reporter cells might affect the mAb 20.1 response since all three TCR‐mediated mAb 20.1‐induced activation of TCR‐transduced Jurkat cells. The pronounced differences between PAg and mAb 20.1‐induced activation observed here help to understand the often contradictory published data. This study provides novel perspectives on the physiological mechanism of Vγ9Vδ2 T‐cell activation, and highlights the complex mode of action of BTN3A‐specific antibodies as agents in cancer immunotherapy.     

The hypervariable region 4 (HV4) and position 93 of the α chain modulate CD1d‐glycolipid binding of iNKT TCRs

TCRs of invariant NKT (iNKT) cells bind α‐galactosylceramide (αGC) loaded CD1d in a highly conserved fashion and show a characteristic TCR gene usage: An “invariant” α chain with a canonical AV14/AJ18 rearrangement in mice (AV24/AJ18 in humans) is paired with β chains containing characteristic Vβ segments. In the rat, a multimember AV14 gene family increases the variability within this system. This study characterizes CD1d binding of rat AV14 gene segments in TCR transductants as well as CD1d binding and iNKT TCR expression of expanded polyclonal F344 rat iNKT populations. It defines an important role of position 93 at the V‐J transition for TCR avidity and species cross‐reactivity of the rat iNKT TCR. Furthermore, for the first time we identified variability within the fourth hypervariable loop (HV4) of the α chain as a modulator of CD1d:αGC binding in rat and mouse. Additionally, we confirmed the importance of the CDR2β for CD1d:αGC binding, but also show that the CDR3β may even have opposite effects on binding depending on the pairing α chain. Altogether, we characterized naturally occurring sources of variability for the iNKT TCR and speculate that they rather level than increase the largely germline encoded differences of iNKT TCR ligand avidity.     

Recent developments in x-ray luminescent imaging systems

The paper is a survey on the latest developments in luminescent x-ray imaging systems. Special attention was given to two problems, the reduction of cross-over in screen-film-systems by variation of the spectrum of luminescence and the development of digital storage phosphor systems. Recent developments in the evaluation of x-ray luminescent screens are also discussed.     

Encephalitis in a stone marten (Martes foina) after natural infection with highly pathogenic avian influenza virus subtype H5N1

Recent outbreaks of disease in different avian species, caused by the highly pathogenic avian influenza virus (HPAIV), have involved infection by subtype H5N1 of the virus. This virus has also crossed species barriers and infected felines and humans. Here, we report the natural infection of a stone marten (Martes foina) from an area with numerous confirmed cases of H5N1 HPAIV infection in wild birds. Histopathological examination of tissues from this animal revealed a diffuse nonsuppurative panencephalitis with perivascular cuffing, multifocal gliosis and neuronal necrosis. Additionally, focal necrosis of pancreatic acinar cells was observed. Immunohistochemically, lesions in these organs were associated with avian influenza virus antigen in neurons, glial cells and pancreatic acinar cells. Thus, the microscopical lesions and viral antigen distribution in this stone marten differs from that recently described for cats naturally and experimentally infected with the same virus subtype. This is the first report of natural infection of a mustelid with HPAIV H5N1.