@article{9b08e68db8f248cdaede6700fbe2ba2b,
title = "Rodent epidermal Langerhans cells demonstrate greater histochemical specificity for ADP than for ATP and AMP",
abstract = "Langerhans cells (LCs) in mammalian epidermis possess the ectoenzyme Ca++/Mg++-dependent adenosine triphosphate (ATPase), which has served as a useful histochemical marker for these dendritic cells in a variety of tissue preparations. Since ATPase represents only one of several potential cell surface polyphosphatases, we investigated the capacities of 3 related adenine nucleotide substrates to identify rodent epidermal LCs. Cell surface ATPase activity was not inhibited in the presence of ouabain and was observed to be strictly divalent cation-dependent, with complete interchange-ability between Ca++ and Mg++. Optimal staining in the presence of either cation occurred at a 20 mM concentration. Substrate concentration dependence was also observed, with optimal staining at 0.33 mM adenosine 5'-triphosphate (ATP). On an equimolar basis, however, adenosine 5'-diphosphate (ADP) was superior to ATP for the identification of LCs both in whole mounts of epidermis and in suspensions of disaggregated epidermal cells. The substrate adenosine 5'-monophosphate (AMP) stained follicular epithelial cells in both rodent species but failed to identify epidermal LCs in the mouse and only weakly stained these dendritic cells in rat epidermis. We conclude from these studies that ADP demonstrates greater specificity for LC surface polyphosphatase activity than ATP and that the inadvertent inclusion of AMP during identification procedures for epidermal cell suspensions will falsely identify cells other than LCs.",
author = "Chaker, {M. B.} and Tharp, {M. D.} and Bergstresser, {P. R.}",
note = "Funding Information: Epidermal Langerhans cells (LCs) in mammalian skin possess the ectoenzyme adenosine triphosphatase (ATPase), the presence of which has been used to identify these dendritic cells histochemically in a variety of skin preparations [1,2]. At least 2 different surface ATPases have been previously identified in cells from other tissues, and have been categorized according to their cation requirements and susceptibility to certain inhibitors. One ATPase group is dependent upon Na+ and K+, and is inhibited in the presence of ouabain [3,4]. The second major group of A TPases functions independently from these monovalent cations but requires Ca++ and Mg++ for its activity, and is resistant to the inhibitory effects of ouabain Manuscript received September 12, 1983; accepted for publication December 7, 1983. Supported in part by USPHS Grant Al-17363. Dr. Tharp is the recipient of a USPHS Clinical Investigator Award, AM-01003. Dr. Chaker is the recipient of an International Fellowship Grant supported by Mr. H. Chehabi. Reprint requests to: Paul R. Bergstresser, M.D., Department of Dermatology, University of Texas Health Science Center at Dallas, Southwestern Medical School, 5323 Harry Hines Boulevard, Dallas, Texas 75235. Abbreviations: AD P: adenosine 5' -diphosphate AMP: adenosine 5 '-monophosphate LC: Langerhans cell PBS: phosphate-buffered saline [5]. Most histochemical techniques employed for the identification of LCs are adaptations from the method of W achstein and Meisel which was originally developed to assess ATPase activity in frozen liver sections (6] . This technique subsequently has been used to identify putative Ca++ /Mg++ -dependent ATPase-positive cells in fixed whole mounts of epidermis and suspensions of disaggregated epidermal cells [7,8]. Cell surface Ca++/Mg++_dependent ATPase may represent only one of several membrane-related cell polyphosphatases requiring these cations. In 1964, using the Wachstein and Meisel histochemical technique, Wolff [9] examined the effects of different adenine nucleotides on frozen sections of normal human skin. He observed that different cutaneous structures possessed disparate specificities for 3 related substrates: ATP, adenosine 5' -diphosphate (ADP), and adenosine 5' -monophosphate (AMP). These and other observations suggested distinct heterogeneity among cutaneous elements for different adenine nucleotide phosphatases. Since 1964, increasing attention has been paid to the immunologic properties of LCs [10-12]. This work has required methods of identifying their enumeration in epidermal whole mounts and in suspensions of disaggregated epidermal cells. ATPase histochemistry has resulted in more accurate measures of LC densities within the epidermis and has provided a crucial step in LC enrichment procedures (8,1 3]. To this date, however, there has been no systematic validation of the W achstein and Meisel technique as it has been applied to these new LC preparations. In addition, the potential of other adenine nucleotides (ADP and AMP) to serve as more specific markers for epidermal LCs has not yet been investigated.",
year = "1984",
doi = "10.1111/1523-1747.ep12261031",
language = "English (US)",
volume = "82",
pages = "496--500",
journal = "Journal of Investigative Dermatology",
issn = "0022-202X",
publisher = "Nature Publishing Group",
number = "5",
}