       Document 0034
 DOCN  M9630034
 TI    The leucocyte protein L1 (calprotectin): a putative nonspecific defence
       factor at epithelial surfaces.
 DT    9603
 AU    Brandtzaeg P; Gabrielsen TO; Dale I; Muller F; Steinbakk M; Fagerhol MK;
       Laboratory for Immunohistochemistry and Immunopathology (LIIPAT),;
       National Hospital, Oslo, Norway.
 SO    Adv Exp Med Biol. 1995;371A:201-6. Unique Identifier : AIDSLINE
       MED/96001503
 AB    The L1 protein occurs at high concentrations in neutrophils, monocytes,
       certain reactive tissue macrophages, squamous mucosal epithelia, and
       reactive epidermis. It constitutes in fact about 60% of the neutrophilic
       cytosol protein fraction. The two L1 chains (L1H and L1L) are referred
       to by a bewildering collection of names, various authors having
       different preferences (MRP-8 and MRP-14; CFA or calgranulin A and B).
       The most recent proposal is calprotectin because of its calcium-binding
       properties and antimicrobial effect shown in vitro. L1 belongs to the
       S-100 protein family and may be involved in the regulation of
       keratinocyte proliferation and differentiation. It exists at high levels
       in blood and interstitial tissue fluid in several infectious,
       inflammatory, and malignant disorders, and it is released abundantly in
       foci of granulocytes and macrophages. The C-terminal sequence of the L1H
       chain has been shown to be identical to the N-terminus of peptides known
       as neutrophil immobilizing factors. Such an activity of L1 could be
       important for the accumulation of vital granulocytes, while L1 released
       from neutrophils, macrophages and epithelial cells might exert
       antimicrobial activity, perhaps by depriving microorganisms of zinc. The
       minimum inhibitory concentrations of L1 in vitro were found to be 4-32
       mg/l for Candida albicans, 64 mg/l for Staphylococcus aureus, 64-256
       mg/l for S. epidermidis, and 256 mg/ml for Escherichia coli and
       Klebsiella spp. Killing was observed at 2-4 times higher concentrations.
       In patients with HIV infection, those who developed oral candidiasis had
       significantly lower parotid L1 levels than those who did not (67
       micrograms/l vs. 216 micrograms/l).
 DE    Antigens, Differentiation/CHEMISTRY/*PHYSIOLOGY  AIDS-Related
       Opportunistic Infections/ETIOLOGY  Calcium-Binding
       Proteins/CHEMISTRY/*PHYSIOLOGY  Candidiasis, Oral/ETIOLOGY
       Epithelium/*CHEMISTRY/PHYSIOLOGY  Genes, Reiterated  Human
       Leukocytes/CHEMISTRY/PHYSIOLOGY  Macrophages/CHEMISTRY/PHYSIOLOGY
       Microbial Sensitivity Tests  Nerve Tissue Protein S 100/CHEMISTRY
       NCAM/CHEMISTRY/*PHYSIOLOGY  Protein Conformation  Salivary
       Proteins/DEFICIENCY/PHYSIOLOGY  Support, Non-U.S. Gov't  JOURNAL ARTICLE
       REVIEW  REVIEW, TUTORIAL

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

