-transparent.png){kind=logo}
Bone marrow-derived leukocytes of murine epidermis can express two phenotypes: typical Langerhans cells, which are Ia+ and Thy-1-, and a recently discovered second population that is Thy-1+ and Ia-. To verify that these phenotypes are expressed by two different cell types, and to help understand their lineage and function, we have studied morphology and reactivity with a large panel of antibodies. Dual antibody immunofluorescence combined with electron microscopy showed that Thy-1+ and Ia+ cells were each distributed in a regular fashion and formed adjacent dendritic systems in or close to the basal layer. Double-labeling studies with anti-Ia and a second monoclonal antibody revealed that all Langerhans cells expressed F4/80 (macrophage), Mac-1 (C3bi receptor), and 2.4G2 (Fc receptor), as well as the thymus leukemia (TL) and heat-stable (M1.69/16) antigens. A large fraction expressed S100 and all exhibited membrane ATPase and nonspecific esterase. In contrast, Thy-1+ cells lacked all these features of Langerhans cells, except that a minority were strongly reactive with 2.4G2. Thy-1+ cells also lacked differentiation antigens of most other types of leukocytes, except they were rich in asialo GM1. By electron microscopy, Thy-1+ cells had cytoplasmic granules that were similar in structure and in their aryl sulfatase content to those previously described in natural killer cells. The granules were enlarged in beige mice, suggesting a lysosomal origin, and were present in mast cell-deficient W/Wv mice, indicating no relation to mast cells. We conclude that Thy-1+ epidermal cells are thoroughly distinct from Langerhans cells. On the basis of morphology and phenotype, they may represent a type of tissue natural killer cell. Thy-1+ natural killer cells are now being identified in several nonlymphoid sites, such as gut epithelium and the livers of mice given adjuvants. If Thy-1+ epidermal cells prove to be natural killer cells, it is noteworthy that they represent a resident population regularly distributed in the basal layer of all mouse strains. The notion that Thy-1+ epidermal cells are immature natural killer cells is intriguing in light of recent evidence that Ia+ Langerhans cells are also immature with respect to accessory cell function. The epidermis may not have the functional capacities of a lymphoid organ, but it could contribute immature cells important for both natural and acquired resistance.
N Romani, and
G Stingl, and
E Tschachler, and
M D Witmer, and
R M Steinman, and
E M Shevach, and
G Schuler
September 1983,
The Journal of investigative dermatology,
N Romani, and
G Stingl, and
E Tschachler, and
M D Witmer, and
R M Steinman, and
E M Shevach, and
G Schuler
April 1986,
The Journal of experimental medicine,
N Romani, and
G Stingl, and
E Tschachler, and
M D Witmer, and
R M Steinman, and
E M Shevach, and
G Schuler
August 1984,
The Journal of investigative dermatology,
N Romani, and
G Stingl, and
E Tschachler, and
M D Witmer, and
R M Steinman, and
E M Shevach, and
G Schuler
July 1984,
The Journal of investigative dermatology,
N Romani, and
G Stingl, and
E Tschachler, and
M D Witmer, and
R M Steinman, and
E M Shevach, and
G Schuler
January 1992,
Journal of dermatological science,
N Romani, and
G Stingl, and
E Tschachler, and
M D Witmer, and
R M Steinman, and
E M Shevach, and
G Schuler
February 1983,
The Journal of experimental medicine,
N Romani, and
G Stingl, and
E Tschachler, and
M D Witmer, and
R M Steinman, and
E M Shevach, and
G Schuler
March 1985,
European journal of immunology,
N Romani, and
G Stingl, and
E Tschachler, and
M D Witmer, and
R M Steinman, and
E M Shevach, and
G Schuler
November 2004,
Proceedings of the National Academy of Sciences of the United States of America,
N Romani, and
G Stingl, and
E Tschachler, and
M D Witmer, and
R M Steinman, and
E M Shevach, and
G Schuler
August 1984,
The Journal of investigative dermatology,
N Romani, and
G Stingl, and
E Tschachler, and
M D Witmer, and
R M Steinman, and
E M Shevach, and
G Schuler
November 1987,
The Journal of investigative dermatology,
