02405nas a2200349   4500000000100000008004100001260001600042653001200058653002300070653002100093653002000114653001400134653002000148653001100168653003000179653002500209653002100234653001300255653001800268653001200286653000900298653000900307100001300316700001500329700001400344700001300358245010800371300001300479490000800492520154100500022001402041       1987                            d  c1987 Oct 0110aAnimals10aAntibody Formation10aChemokine CXCL1010aChemokines, CXC10aCytokines10aHLA-DR Antigens10aHumans10aHypersensitivity, Delayed10aImmunohistochemistry10aInterferon-gamma10aKeratins10aLeishmaniasis10aleprosy10aMice10aSkin1 aKaplan G1 aLuster A D1 aHancock G1 aCohn Z A00aThe expression of a gamma interferon-induced protein (IP-10) in delayed immune responses in human skin.  a1098-1080 v1663 a<p>Our knowledge of the induction of new molecules by IFN-gamma has led to the characterization of IP-10 and the preparation of a monospecific, polyclonal antibody. Using this reagent we have now examined inflammatory states occurring in human skin and used immunocytochemical staining for the expression of both Ia and IP-10 determinants. After evoking a delayed-type response to purified protein derivative of tuberculin (PPD), we noted the presence of IP-10 in dermal macrophages and endothelial cells. Intense staining of the basal layer of epidermal keratinocytes was prominent at 41 h, and by 1 wk the entire epidermis was staining. The comparison of the amount of IP-10 secreted by keratinocytes vs. macrophages, fibroblasts, and endothelial cells revealed that keratinocytes were by far the major producers of this molecule. The expression of Ia occurred in conjunction with IP-10. The injection of rIFN-gamma mimicked many of the features of the PPD response, including the expression of both Ia and IP-10 by epidermal keratinocytes. Coexpression was also found in the natural lesions of tuberculoid leprosy and cutaneous Leishmaniasis. However, it was absent in lepromatous leprosy, a state where activated T lymphocytes are not present. We suggest that the local production of IFN-gamma by T cells of the dermal infiltrate induces IP-10 formation in both the dermis and epidermis. IP-10 and Ia then serve as specific markers of immune IFN and its possible influence on effector cells of the cell mediated immune response.</p>  a0022-1007