title: Characterization of functional mannose receptor in a continuous hybridoma cell line.
abstract: BACKGROUND
  The mannose receptor is the best described member of the type I transmembrane C-type lectins; however much remains unanswered about the biology of the receptor. One difficulty has been the inability to consistently express high levels of a functional full length mannose receptor cDNA in mammalian cells. Another difficulty has been the lack of a human macrophage cell line expressing a fully functional receptor. Commonly used human macrophage cell lines such as U937, THP-1, Mono-Mac and HL60 do not express the mannose receptor. We have developed a macrophage hybridoma cell line (43MR cells) created by fusion of U937 cells with primary human monocyte-derived macrophages, resulting in a non-adherent cell line expressing several properties of primary macrophages. The purpose of this study was to identify and select mannose receptor-expressing cells using fluorescence-activated cell sorting and to characterize the expression and function of the receptor.
  
  
  RESULTS
  In the current study we show that the mannose receptor found on this novel cell has endocytic characteristics consistent with and similar to the mannose receptor found on the surface of monocyte-derived human macrophages and rat bone marrow-derived macrophages. In addition, we demonstrate that these cells engage and internalize pathogen particles such as S. aureus and C. albicans. We further establish the transfectability of these cells via the introduction of a plasmid expressing influenza A hemagglutinin.
  
  
  CONCLUSIONS
  The 43MR cell line represents the first naturally expressed MR-positive cell line derived from a human macrophage background. This cell line provides an important cell model for other researchers for the study of human MR biology and host-pathogen interactions.
authors.affiliation: Department of Veterans Affairs Medical Center, VA Medical Center/Research Service, 1310 24th Ave,, South, Nashville TN 37212, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Vigerust
authors.forename: Sherell
authors.initials: S
authors.lastname: Vick
authors.forename: Virginia L
authors.initials: VL
authors.lastname: Shepherd
mesh_terms: D000818:Animals; D002176:Candida albicans / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D005434:Flow Cytometry; D049452:Green Fluorescent Proteins / Q000378:metabolism; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000378:metabolism; D006801:Humans; D006825:Hybridomas / Q000166:cytology / Q000378:metabolism*; D015151:Immunoblotting; D037181:Lectins, C-Type / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D008264:Macrophages / Q000166:cytology / Q000378:metabolism / Q000382:microbiology; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins / Q000235:genetics / Q000378:metabolism*; D010587:Phagocytosis; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013211:Staphylococcus aureus / Q000378:metabolism; D014162:Transfection
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D037181:Lectins, C-Type; D008024:Ligands; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D011956:Receptors, Cell Surface; D049452:Green Fluorescent Proteins