Ontogeny and thymus-dependence of T cell surface antigens in Xenopus : flow cytometric studies on monoclonal antibody-stained thymus and spleen

Minor Histocompatibility Antigen-Specific MHC-Restricted CD8 T Cell Responses Elicited by Heat Shock Proteins

“…The anti-CD8 mAb AM22 binds a polypeptide of 30 -32 kDa as determined by Western blotting (28), and it immunoprecipitates a dimeric complex of 65 kDa under nonreducing conditions that resolves to a 35-kDa band and a 30-to 32-kDa band under reducing conditions (26). Xenopus CD8 T cells stained with either of the two anti-CD8 mAbs express a pan-T cell marker (XT-1), high levels of CD5, and CD45 (55-57); these cells are not detectable in animals that had been thymectomized at early developmental stages before the migration of stem cells into the thymus (55). Finally, in vitro studies suggest that the mammalian type of thymocyte differentiation (i.e., immature double-positive CD4CD8 cells giving rise to more mature single positive CD4 ϩ CD8 Ϫ and CD4 Ϫ CD8 ϩ ) also occurs in both MHC class I-negative larvae and class I-expressing adults (56,57).…”

Xenopus NK cells identified by novel monoclonal antibodies

“…Thymectomy of larvae by microcautery was carried out at 5-6 days of age, when the thymus is at a rudimentary stage of differentiation [12,37,38]. Controls were non-operated siblings.…”

“…m) of spleen and small intestine from control and Tx Xenopus were fixed in methanol before incubation with anti-NK mAb. mAb staining was detected by either a biotin-avidin-peroxidase technique (ABC kit, Vector Labs) as described elsewhere [38] or by use of FITCconjugated anti-mouse Ig (DAKO).…”

Tolerance Induction in Thymectomized, Adult Xenopus by Co-Transplantation of Thymus and Tolerated Skin Graft

“…This result was surprising because E-Txd animals have repeatedly been shown to have very few thymocytes (Horton, 1997) and therefore, cannot reject either JB or even totally xenogeneic BB skin grafts (Horton et al, 1992). In addition, it is hard to explain why L-Txd adults, which are known to have some thymus-derived cells (Gravenor et al, 1995) and to show slightly depressed mitogen responses (Rollins-Smith et al, 1996), were rendered tolerant by transplantation with tol-JB skin (Table 2). From these observations, we conclude that the tol-JB skin grafts contain several types of cell populations derived from the primary host (JJ larvae transplanted with JB skin grafts that were tolerated for 4-5 weeks): 1) cells which suppress the JB skin-graft rejection (Ono and Tochinai, 1995); 2) cells which are primed to destroy JB skin grafts; and 3) other immunoreactive cells such as passenger antigen presenting cells (APCs).…”