Understanding Influenza

Influenza, a serious illness of humans and domesticated animals, has been studied intensively for many years. It therefore provides an example of how much we can learn from detailed studies of an infectious disease and of how even the most intensive scientific research leaves further questions to answer. This introduction is written for researchers who have become interested in one of these unanswered questions, but who may not have previously worked on influenza. To investigate these questions, researchers must not only have a firm grasp of relevant methods and protocols; they must also be familiar with the basic details of our current understanding of influenza. This article therefore briefly covers the burden of disease that has driven influenza research, summarizes how our thinking about influenza has evolved over time, and sets out key features of influenza viruses by discussing how we classify them and what we understand of their replication. It does not aim to be comprehensive, as any researcher will read deeply into the specific areas that have grasped their interest. Instead, it aims to provide a general summary of how we came to think about influenza in the way we do now, in the hope that the reader’s own research will help us to understand it better

In Vitro

Producción CientíficaPURPOSE: Transplantation of autologous corneal stem cells in not possible in cases of bilateral limbal stem cell deficiency (LSCD). To restore the ocular surface in these patients, an autologous extraocular source of stem cells is desirable to avoid dependence on deceased donor tissue and host immunosuppression of allogenic transplants. While bone marrow-derived mesenchymal stem cells (MSCs) can acquire certain characteristics of corneal epithelial cells, subcutaneous adipose tissue (AT) is more readily available and accessible. The aim of this study was to determine if extraocular human AT-derived MSCs (hAT-MSCs) can acquire in vitro some features of corneal epithelial-like cells. METHODS: hAT-MSCs were isolated from human lipoaspirates and expanded up to 3-4 passages. We studied the immunophenotype of MSCs and demonstrated its multipotent capacity to differentiate towards osteoblasts, adipocytes, and chondrocytes. To test the capacity of differentiation of hAT-MSCs towards corneal epithelial-like cells, hAT-MSCs were cultured on substrata of plastic or collagen IV. We used basal culture medium (BM), BM conditioned with human corneal epithelial cells (HCEcBM), and BM conditioned with limbal fibroblasts (LFcBM). RESULTS: The hAT-MSCs incubated for 15 days with HCEcBM acquired more polygonal and complex morphology as evaluated by phase-contrast microscopy and flow cytometry. Additionally, the expression of transforming growth factor-β receptor CD105 and corneal epithelial marker CK12 got increased as evaluated by flow cytometry, real-time reverse-transcription polymerase chain reaction, western-blot, and immunostaining. These changes were absent in hAT-MSCs incubated with unconditioned BM or with LFcBM. CONCLUSIONS: Corneal epithelial-like cells can be induced from extraocular hAT-MSCs by subjecting them to an in vitro microenvironment containing conditioning signals derived from differentiated human corneal epithelial cells. Our results suggest that hAT-MSCs could provide a novel source of stem cells that hold the potential to restore sight lost in patients suffering from bilateral ocular surface failure due to LSCD.Este trabajo fue financiado con fondos procedentes de: Instituto de Salud Carlos III (CIBER-BBN, CB06/01/003), Ministerio de Ciencia e Innovación (SAF2010-14900), Junta de Castilla y León (SAN126/VA12/09). S.G. participó en la realización de este trabajo con un contrato predoctoral de la Junta de Castilla y León y el Fondo Social Europeo