61 research outputs found

    A novel family of diversified immunoregulatory receptors in teleosts is homologous to both mammalian Fc receptors and molecules encoded within the leukocyte receptor complex

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    Three novel and closely related leukocyte immune-type receptors (IpLITR) have been identified in channel catfish (Ictalurus punctatus). These receptors belong to a large polymorphic and polygenic subset of the Ig superfamily with members located on at least three independently segregating loci. Like mammalian and avian innate immune regulatory receptors, IpLITRs have both putative inhibitory and stimulatory forms, with multiple types coexpressed in various lymphoid tissues and clonal leukocyte cell lines. IpLITRs have an unusual and novel relationship to mammalian and avian innate immune receptors: the membrane distal Ig domains of an individual IpLITR are related to fragment crystallizable receptors (FcRs) and FcR-like proteins, whereas the membrane proximal Ig domains are related to several leukocyte receptor complex encoded receptors. This unique composition of Ig domains within individual receptors supports the hypothesis that functionally and genomically distinct immune receptor families found in tetrapods may have evolved from such ancestral genes by duplication and recombination events. Furthermore, the discovery of a large heterogeneous family of immunoregulatory receptors in teleosts, reminiscent of amphibian, avian, and mammalian Ig-like receptors, suggests that complex innate immune receptor networks have been conserved during vertebrate evolution. ELECTRONIC SUPPLEMENTARY MATERIAL: Supplementary material is available for this article at http://dx.doi.org/10.1007/s00251-006-0134-1 and is accessible for authorized users

    Virus Movements on the Plasma Membrane Support Infection and Transmission between Cells

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    How viruses are transmitted across the mucosal epithelia of the respiratory, digestive, or excretory tracts, and how they spread from cell to cell and cause systemic infections, is incompletely understood. Recent advances from single virus tracking experiments have revealed conserved patterns of virus movements on the plasma membrane, including diffusive motions, drifting motions depending on retrograde flow of actin filaments or actin tail formation by polymerization, and confinement to submicrometer areas. Here, we discuss how viruses take advantage of cellular mechanisms that normally drive the movements of proteins and lipids on the cell surface. A concept emerges where short periods of fast diffusive motions allow viruses to rapidly move over several micrometers. Coupling to actin flow supports directional transport of virus particles during entry and cell-cell transmission, and local confinement coincides with either nonproductive stalling or infectious endocytic uptake. These conserved features of virus–host interactions upstream of infectious entry offer new perspectives for anti-viral interference

    The supernatural characters and powers of sacred trees in the Holy Land

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    This article surveys the beliefs concerning the supernatural characteristics and powers of sacred trees in Israel; it is based on a field study as well as a survey of the literature and includes 118 interviews with Muslims and Druze. Both the Muslims and Druze in this study attribute supernatural dimensions to sacred trees which are directly related to ancient, deep-rooted pagan traditions. The Muslims attribute similar divine powers to sacred trees as they do to the graves of their saints; the graves and the trees are both considered to be the abode of the soul of a saint which is the source of their miraculous powers. Any violation of a sacred tree would be strictly punished while leaving the opportunity for atonement and forgiveness. The Druze, who believe in the transmigration of souls, have similar traditions concerning sacred trees but with a different religious background. In polytheistic religions the sacred grove/forest is a centre of the community's official worship; any violation of the trees is regarded as a threat to the well being of the community. Punishments may thus be collective. In the monotheistic world (including Christianity, Islam and Druze) the pagan worship of trees was converted into the worship/adoration of saints/prophets; it is not a part of the official religion but rather a personal act and the punishments are exerted only on the violating individual

    Medical follow-up for workers exposed to bladder carcinogens: the French evidence-based and pragmatic statement

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