Induction of regulatory T cells from mature T cells by allogeneic thymic epithelial cells in vitro

Abstract

Summary The ability of thymic epithelial cells (TEC) to re‐educate mature T cells to be regulatory T cells has not been addressed. In the present study, this issue was directly investigated by co‐culturing of mature T cells and allo‐TECs. B6 macrophage cell line 1C21‐cultured BALB/c splenocytes responded to B6 antigens in vitro. However, BALB/c splenocytes precultured with B6‐derived TECs 1‐4C18 or 1C6 did not proliferate to B6 antigens, but responded to rat antigens. Exogenous interleukin‐2 (IL‐2) failed to revise the unresponsiveness of these T cells. Allo‐TEC‐cultured T cells predominantly expressed Th2 cytokines (IL‐4 and IL‐10). B6 TEC‐cultured BALB/c splenocytes markedly inhibited the immune responses of naïve BALB/c splenocytes to B6 antigens, but not to rat or the third‐party mouse antigens. BALB/c nude mice that received naïve syngeneic splenocytes rejected B6 or rat skin grafts by 17 days postskin grafting; however, co‐injection of B6 TEC‐cultured BALB/c splenocytes significantly delayed B6 skin graft rejection (P < 0.01), with the unchanged rejection of rat skin grafts. These studies demonstrate that allo‐TECs are able to ‘educate’ mature T cells to be regulatory cells, and suggest that regulatory cells derived from mature T cells by TECs may play an important role in T cell tolerance to allo‐ and auto‐antigens.

Immunosuppressive Effects of Ginsenoside-Rd on Skin Allograft Rejection in Rats

“…The spleens of the Kunmimg mice were harvested under sterile conditions and grinded gently on the fine steel mesh. A single-cell suspension was obtained by passing the splenocytes through a 200-mesh cell sieve, and erythrocytes were lysed by lysing buffer (17 mM Tris-HCl and 140 mM NH 4 Cl, pH7.2) as described before [4]. The cells were centrifugated at 600 g for 10 min at 4 C and resuspended in RPMI-1640 medium supplemented with 10% heat-inactivated fetal calf serum, 100 U/mL penicillin, and 100 mg/mL streptomycin.…”

2-Gy whole-body irradiation significantly alters the balance of CD4+CD25−T effector cells and CD4+CD25+Foxp3+T regulatory cells in mice

“…31 Splenocytes were treated with a hemolysis buffer (17 mM Tris-HCl and 140 mM NH 4 Cl, pH 7.2) to remove red blood cells as described previously. 32 Immunofluorescence staining and flow cytometry (FCM) PBMCs, LNs, splenocytes or thymocytes (5310 5 ) were incubated with 2.4G2 to block non-specific staining by FcRs and then incubated with an optimal concentration of fluorochrome-labeled mAbs for 30 min at 4 uC in dark. Cells were washed three times and resuspended in FCM buffer (phosphate buffered saline with 0.1% bovine serum albumin and 0.1% NaN 3 ).…”

The macrophage heterogeneity: Difference between mouse peritoneal exudate and splenic F4/80+ macrophages

“…Cells were suspended in RPMI1640 medium supplemented with 10% (vol/vol) mouse serum, 2 mM L-glutamine, 0.1 mM non-essential amino acids (GibcolBrl), 1 mM sodium pyruvate, 10 U/ml penicillin and 10 mg/ml streptomycin, 10 mM HEPES buffer (GibcolBrl), and 10 mM 2-mercaptoethanol (Sun et al, 2006). Triplicate wells containing 2 Â 10 5 responders with 1 Â 10 5 or with the indicated doses of allogeneic macrophage stimulators (pretreated with 50 mg/ ml mitomycin C) in a total volume of 0.2 ml of medium were incubated in U-bottomed 96-well microplates (Costar) at 378C in 5% CO 2 .…”