CD3+ and Pax5+ Lymphocytes were not Found in the Dermis of Normal Skin from the Dorsolateral Thorax of Dogs

Abstract

Abstract:A small population of resident T-lymphocytes are present in the healthy epidermis of skin from humans, mice, cattle, sheep, and alpacas. In addition, small numbers of resident T-lymphocytes are present in the dermis of normal skin of humans, cattle, and sheep. The objective of this study was to determine the prevalence of lymphocytes, CD3+ cells (T-lymphocytes) and Pax5+ (B-lymphocytes) cells in the superficial and deep dermis of normal dog skin. Skin-biopsy specimens from the normal skin of the dorsolateral thorax from 26 dogs were examined histologically and immunohistochemically for the presence of CD3+ and Pax5+ cells in the superficial and deep dermis. All examinations were negative. It appears that lymphocytes rarely occur, or occur in very small numbers, in the superficial and deep dermis of normal dog skin.

CD3+ and Pax5+ Lymphocytes in the Dermis of Normal Skin from the Dorsolateral Thorax of Cats

“…The importance and presence of resident lymphocyte populations have been evaluated within the dermis and epidermis of humans, mice, cattle, sheep, alpacas, horses, and dogs [2][3][4][5][6][7][8][9] . The epidermis and adnexal epithelia of normal cats has been shown to contain no lymphocytes positive for CD3 (expressed on T cells) or BLA36 (expressed on B cells) 17) .…”

“…Resident dermal T-lymphocytes were also described in cattle 9) , sheep 8) , and alpacas 7) , predominately in a perivascular location, and in larger numbers around superficial than deep dermal blood vessels. CD3+ T-lymphocytes were found in very small numbers in the dermis of normal dog skin in two small studies 11,15) , but were not detected in a third larger study 6) . In two small studies, dermal lymphocytes were found in 0 of 10 12) , and 2 of 6 16) normal cats.…”

“…Specimens were collected from the dorsolateral thorax just after euthanasia using a 6-mm biopsy punch and were then formalin-fixed and paraffin-embedded. The skin over the dorsolateral thorax was used because (1) it is commonly biopsied and (2) it was used in previous studies in dogs 6) and alpacas 7) . Serial sections (4 μm thick) from each block were stained with antibodies against CD3 and Pax5.…”

“…Immunohistochemistry for CD3 and Pax5 was performed as previously described in similar studies 6,7) .…”

CD3+ lymphocytes predominate in the dermis, epidermis, and adnexal epithelia of the normal dorsolateral thorax of horses

“…CD3+ dermal lymphocytes, predominantly in a superficial perivascular distribution, as well as intraepithelial lymphocytes are also present in mice 23) , domestic alpacas 6) , cattle 14) , and sheep 10) . In contrast, resident dermal and intraepithelial lymphocytes do not appear to be a consistent finding within the dermis 5,20) or epidermis of dogs 4,20) and cats 8,24) .…”