In January 2022, West Nile virus (WNV) lineage 2 (L2) was detected in an adult female goshawk rescued near Perugia in the region of Umbria (Italy). The animal showed neurological symptoms and died 15 days after its recovery in a wildlife rescue center. This was the second case of WNV infection recorded in birds in the Umbria region during the cold season, when mosquitoes, the main WNV vectors, are usually not active. According to the National Surveillance Plan, the Umbria region is included amongst the WNV low-risk areas. The necropsy evidenced generalized pallor of the mucous membranes, mild splenomegaly, and cerebral edema. WNV L2 was detected in the brain, heart, kidney, and spleen homogenate using specific RT-PCR. Subsequently, the extracted viral RNA was sequenced. A Bayesian phylogenetic analysis performed through a maximum-likelihood tree showed that the genome sequence clustered with the Italian strains within the European WNV strains among the central-southern European WNV L2 clade. These results, on the one hand, confirmed that the WNV L2 strains circulating in Italy are genetically stable and, on the other hand, evidenced a continuous WNV circulation in Italy throughout the year. In this report case, a bird-to-bird WNV transmission was suggested to support the virus overwintering. The potential transmission through the oral route in a predatory bird may explain the relatively rapid spread of WNV, as well as other flaviviruses characterized by similar transmission patterns. However, rodent-to-bird transmission or mosquito-to-bird transmission cannot be excluded, and further research is needed to better understand WNV transmission routes during the winter season in Italy.
In this study, we have evaluated 14 large granular lymphocyte (LGL) expansions, 11 of which were CD8+. Analysis of the membrane expression of the alpha and beta chains of the CD8 antigen, using specific monoclonal antibodies (MoAbs), has shown that LGL expansions with the CD3+, CD4+, CD8+, CD57+ T-cell receptor (TcR) alpha beta phenotype bear the CD8 alpha/alpha isoform, while the CD3+, CD4-, CD8+, CD57+ TcR alpha beta samples were positive for both the CD8 alpha and CD8 beta chains. These data were confirmed also by messenger RNA analysis. One additional case, with a peculiar phenotype (CD3-, CD2-, CD4-, CD8+, CD57-) and a germline configuration of the TcR beta and gamma chain genes, expressed only the CD8 alpha chain. After additional phenotypic analysis with a wider panel of MoAbs, it was found that the beta chain of the interleukin-2 receptor was constitutively expressed on the majority of the samples tested, and that most of the monoclonal samples coexpressed CD45RA/R0 antigens. Using MoAbs directed against the variable regions of the TcR beta chain, we could show a preferential V beta region restriction in the CD8+ monoclonal cases. This more extensive characterization of CD8+ LGL expansions has further documented the marked heterogeneity within this rare condition and allowed a better phenotypic dissection between the monoclonal and polyclonal cases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.