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

Abstract

Very small numbers of resident T-lymphocytes are present in the dermis of normal skin of humans, cattle, sheep, dogs, and alpacas. The objective of this study was to determine the prevalence of lymphocytes, CD3+ cells (T-lymphocyte), and Pax5+ cells (B-lymphocyte) in the dermis of normal cat skin. Skin-biopsy specimens from the normal skin of the dorsolateral thorax from 29 cats were examined immunohistochemically for the presence of CD3+ and Pax5+ cells in the superficial and deep dermis. Two CD3+ lymphocytes were found in the superficial dermis in 1 of 29 cats. B-lymphocytes were not found.

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

“…It is interesting to note that in domestic veterinary species significant numbers of resident dermal lymphocytes have only been described in large animal species including cattle 14) , sheep 10) , alpacas 6) , and horses 13) . Similar studies in cats 8) and dogs 5) have reported only rare dermal lymphocytes in few animals.…”

“…Resident dermal and epidermal T lymphocytes are a component of the skin immune system (SIS) in humans 2, 21) and mice 23) . This is probably also true in other domestic species in which resident dermal and epidermal lymphocytes have been detected 3,6,8,10,13,14) .…”

“…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) .…”

“…The presence of B lymphocytes across domestic species is quite variable. B lymphocytes have not been demonstrated in normal skin of cats 8,24) , dogs 4, 5) , or horses 25) . In normal alpaca skin, there has been mixed results with some demonstrated in the dermis 6) , but not in the epidermis or adnexal epithelia 3) .…”