A study of cells present in peripheral lymph of pigs with special reference to a type of cell resembling the langerhans cell

Abstract

Large mononuclear cells with long, actively moving cytoplasmic veils were observed in lymph coming from the skin. The enzyme histochemistry and ultrastructure of these cells suggested that they are related to epidermal Langerhans cells and interdigitating cells in the lymph node. It has been reported that Langerhans cells and interdigitating cells play a role in contact hypersensitivity by taking up antigen and presenting it to thymus-dependent lymphocytes, and it is likely that the veiled cells in the lymph are also involved. After skin-painting with 1-fluoro-2,4-dinitrobenzene (DNFB), the veiled cells in lymph coming from the site of painting became more active and were observed contacting other cells present in the lymph; many large cellular aggregates were found. Since neutrophilic leucocytes and mononuclear phagocytes were the predominating cell types in this lymph, there was no evidence for a massive recruitment of immunocompetent lymphocytes at the site of painting. Neonatally thymectomized pigs do not develop allergic reactivity to DNFB. It is of interest that the number of veiled cells and their ability to form large cellular aggregates was not affected in these animals. Therefore, it is unlikely that the defect in responsiveness can be attributed to a failure in the function of veiled cells.

Flt3 ligand generates morphologically distinct semimature dendritic cells in ovalbumin-sensitized mice

“…They were first observed in large mononuclear cells found in lymph. Upon encounter with allergens, veiled cells in the lymph are involved in contacting and aggregating other cells like neutrophils and mononuclear phagocytes (Drexhage et al, 1979). Langerhans cells display pronounced cytoplasmic veils and are considered to be partially mature (Stoitzner et al, 2002).…”

Dendritic cells: Understanding immunogenicity

“…William Bowers [41,42] and Don Mason and Gordon MacPherson [25,43] found active nonadherent accessory cells in thoracic duct lymph of rats, while Brigid Balfour, Hemmo Drexhage and Stella Knight [44][45][46] described similar veiled cells in the afferent lymph of rabbits and guinea pigs. These early observations on distinct cells in different tissues and species were brought together in a review in 1982, where ideas of a DC system were considered [47].…”

Early Infection of Interdigitating Dendritic Cells in the Pig Lymph Node with African Swine Fever Viruses of High and Low Virulence: Immunohistochemical and Ultrastructural Studies

“…25,27 Only veiled cells have been described in the pig. 7 Veiled cells are considered to be LCs in afferent lymph migrating to the lymph node where they mature into IDCs. 2,5,7 Dendritic cells in domestic animals have received very limited attention, probably because of difficulties encountered in extracting these cells from lymphoid tissues and the very small yield of cells.…”

“…7 Veiled cells are considered to be LCs in afferent lymph migrating to the lymph node where they mature into IDCs. 2,5,7 Dendritic cells in domestic animals have received very limited attention, probably because of difficulties encountered in extracting these cells from lymphoid tissues and the very small yield of cells. In addition, there are few unique markers for dendritic cells that allow definitive differentiation of these cells from macrophages, particularly in paraffin-embedded tissue.…”