Ex vivo model of inflamed human skin and uses thereof for screening anti-inflammatory compounds

An in vitro method for evaluating the anti-inflammatory efficacy of a compound in an ex vivo model of inflamed skin comprising the following steps:

• a) injecting a first composition, using a hollow needle into the reticular dermis of a healthy mammalian skin biopsy having a thickness of 3 mm to 1 cm, which is a mammalian skin fragment comprising at least the epidermis, the dermis, the epidermal appendages and a portion of the hypodermis, wherein the first composition comprises an effective amount of an anti-CD3 antibody and an anti-CD28 antibody for activating dermal resident T cells, thus allowing homogeneous diffusion of the first composition into all tissues of the biopsy, and activation of the resident T cells of the dermis in the injected mammalian skin biopsy;
• a′) depositing the injected mammalian skin biopsy obtained at the end of step a) on a liquid matrix capable of solidifying, said matrix being itself contained in a cell culture insert the bottom of which consists of a porous membrane and said insert being arranged in a container or well, so as to allow, once the matrix has solidified, the 3D integrity of the injected mammalian skin biopsy to be maintained;
• b) incubating the injected mammalian skin biopsy deposited in step a′) for at least 3 days in the presence of a second composition comprising an effective amount of a mixture comprising at least IL-1β, IL-23, and TGF-β for obtaining polarization of the T cells activated in step a) into LTh1 polarized T cells and/or LTh17 polarized T cells, and synthesis of inflammation markers, to form the ex vivo model of inflamed skin;
• c) contacting the ex vivo model of inflamed skin with a candidate compound, wherein the ex vivo model of inflamed skin comprises LTh1-polarized T cells and/or LTh17-polarized T cells;
• d) measuring an expression level of at least two inflammation markers of the model of inflamed skin;
• e) comparing the expression level of said at least two inflammation markers obtained in step d) with a control expression level;
• and
• f) identifying the anti-inflammatory efficacy of said candidate compound when the expression level of said at least two inflammation markers measured in step d) is lower than the control expression level,
• wherein said ex vivo model reflects more precisely and reproducibly the environment of inflamed skin as observed in vivo in a physiological context.