Preferential tissue localization of bovine gamma delta T cell subsets defined by anti-T cell receptor for antigen antibodies

Clonal and oligoclonal populations of gamma delta T cells, with respect to the expression of T cell receptors for antigen (Tcr), have been shown to lo calize in normal and inflamed tissues. The mechanisms responsible for the t issue-selective accumulation of these subsets are still not known, gamma de lta T cells are the predominant T cell subset in newborn calves, making thi s animal a useful model to study these cells. However, molecular markers de fining tissue-specific bovine gamma delta T cell subsets are only now being developed. In this report, we describe three new anti-bovine gamma delta T cr mAbs: GD3.8, GD197 and GD3.1, which provide useful tools to study these cells. GD3.8 recognized virtually all gamma delta T cells in the blood; whe reas GD3.1 and GD197 recognized mutually exclusive as well as overlapping s ubsets. Using these three mAbs, four separate subsets of gamma delta T cell s were defined: subset 1 (GD3.8 +, GD3.1 +, GD197 -); subset 2 (GD3.8 +, GD 3.1 -, GD197 +); subset 3 (GD3.8 +, GD3.1 +, GD197 +); and subset 4 (GD3.8 f, GD3.1 -, GD197 -). Subset 4 constituted a minor population in the blood; however, it predominated in the spleen and, in some cases, represented a 3 00% increase over blood levels. The percentage of GD3.1-positive gamma delt a T cells was found to be increased in experimentally inflamed lymph nodes, suggesting that subset 1 cells may be preferentially retained in or recrui ted to sites of inflammation. Some subset 4 cells also exhibited a decrease d ability to respond to PHA. These studies demonstrate that bovine gamma de lta T cell, Tcr-defined subsets, exhibit unique accumulation and activation characteristics that may provide clues to their function and regulation. ( C) 1998 Elsevier Science B.V. All rights reserved.