Fachbereich Veterinärmedizin



    Equine cytokines (GM-CSF & IL-4) and MoDC differ from humans or mice (2002)

    Mauel, S.
    Steinbach, F.
    7. International Symposium on Dendritic Cells
    Bamberg, 19. – 24.09.2002
    Scientific Program and Abstracts / 7. International Symposium on Dendritic Cells
    — S. 126
    Institut für Virologie

    Robert-von-Ostertag-Str. 7-13
    Gebäude 35
    14163 Berlin
    Tel. +49 30 838 51833 Fax. +49 30 838 451847

    Abstract / Zusammenfassung

    DC can be isolated from skin as epidermal Langerhans cells, from various tissues or
    generated from monocytes (MoDC). For differentiating MoDC and for in vitro culture of
    DC, eq.GM-CSF and eq.IL-4 are necessary cytokines. Both cytokines are considered
    species-specific. Using degenerated primers delineated from other species, cDNA of the
    ORFs coding for eq.GM-CSF and eq.IL-4 were cloned. The coding region of the cytokine
    was cloned in various expression systems. For eq.GM-CSF RACE cloning for the 3’
    terminus was performed also. For differentiating MoDC, monocytes were stimulated with
    the equine Cytokines. MoDC were analysed by light- and electronmicroscopy, flow
    cytometry and MLR.
    RACE and revealed that eq.GM-CSF is distinctly related to hu.GM-CSF with an amino
    acid homology of just 77 %, whereas other species have homologies to each other of more
    than 90 %. Additionally, a point deletion at the 3’ end of the ORF, resulted in a 24
    nucleotides extended ORF not described in any species thus far. Computer analysis of the
    resulting protein indicates an altered N-terminus of the protein, as the human signal peptide
    cleavage site was not conserved either. Cloning of eq.IL-4 revealed a new sequence
    distantly related to other species. Strikingly and in contrast to previous reports in other
    species, human and equine GM-CSF were cross-reactive and could be used to stimulate
    equine MoDC, although a much higher concentration of hu.GM-CSF was required (20-
    fold). IL-4 in contrast was strictly species specific indeed. Using eq.GM-CSF or hu.GMCSF
    plus eq.IL-4, MoDC were generated with the typical morphology and function of DC,
    including the ability to stimulate allogeneic T cells in a MLR. In contrast to the human
    system, however, monocytes had to be differentiated for 5-6 days before MoDC were
    obtained from horses.