P-232

Low effect of anti-thymocyte globuline monotherapy in non-obese diabetic (NOD) mice treated after the onset of overt diabetes

K. Zacharovova¹, L. Pektorova¹, I. Leontovyc¹, E. Dovolilova¹, L. Vojtova², F. Saudek^1
1 IKEM, Laboratory of pancreatic islets, Prague, Czech Republic; ² IKEM, Department of experimental medicine, Prague, Czech Republic

Objective: Experimental and clinical studies showed that autoimmunity causing diabetes may be abrogated by immune intervention. Several anti-T-lymphocyte antibodies focused on different T-cell targets showed remarkable promise. We tested the effect of murine ATG (Genzyme) in NOD mice after the onset of hyperglycemia.

Methods: Diabetic NOD mice were treated with 2 doses of ATG (1 mg totally) or kept without treatment as controls. Blood glucose level was monitored twice a week. The mice were terminated at day 0, 7, 14 or 28 after the initiation. Intraperitoneal glucose tolerance test (IPGT) was performed on day 24. Subpopulations of T-lymphocytes and FoxP3+ regulatory T-cells were analyzed among cells isolated from spleen and pancreatic lymph nodes.

Results: Mice with blood glucose levels higher that 13 mmol/L were included into the study. Diabetes remission occurred in 16 % (3/19) of mice treated with ATG. In all of them pre-treatment blood glucose was 15.6 mmol/l and lower. Only one case of remission was observed in control group (6 %, 1/16).

Though the IPGT was out of normal range in all diabetic animals, coefficient of glucose assimilation was significantly higher in the ATG group (0.36 versus 0.12 mmol/L/min).

ATG therapy lead to a significant decrease of CD8+/CD4+ T-lymphocyte ratio in comparison to the control group; in splenocytes, a significant difference was detected only on day 7 (0.069 vs. 0.198); in lymph nodes decrease was found even on day 28 (0.21 vs. 0.51). Population of the regulatory T-cells was increased after ATG administration in comparison to the control group at day 7 (16,2% vs 10,8% in splenocytes; 20.7% vs. 10.3% in lymph node cells). However, the increase of the population of FoxP3+ cells was not durable.

Conclusions: ATG treatment of diabetic NOD mice showed only a partial metabolic improvement in already hyperglycemic NOD mice.

Supported by No.P304/10/0762.

P-232

Low effect of anti-thymocyte globuline monotherapy in non-obese diabetic (NOD) mice treated after the onset of overt diabetes

K. Zacharovova¹, L. Pektorova¹, I. Leontovyc¹, E. Dovolilova¹, L. Vojtova², F. Saudek^1
1 IKEM, Laboratory of pancreatic islets, Prague, Czech Republic; ² IKEM, Department of experimental medicine, Prague, Czech Republic

Objective: Experimental and clinical studies showed that autoimmunity causing diabetes may be abrogated by immune intervention. Several anti-T-lymphocyte antibodies focused on different T-cell targets showed remarkable promise. We tested the effect of murine ATG (Genzyme) in NOD mice after the onset of hyperglycemia.

Methods: Diabetic NOD mice were treated with 2 doses of ATG (1 mg totally) or kept without treatment as controls. Blood glucose level was monitored twice a week. The mice were terminated at day 0, 7, 14 or 28 after the initiation. Intraperitoneal glucose tolerance test (IPGT) was performed on day 24. Subpopulations of T-lymphocytes and FoxP3+ regulatory T-cells were analyzed among cells isolated from spleen and pancreatic lymph nodes.

Results: Mice with blood glucose levels higher that 13 mmol/L were included into the study. Diabetes remission occurred in 16 % (3/19) of mice treated with ATG. In all of them pre-treatment blood glucose was 15.6 mmol/l and lower. Only one case of remission was observed in control group (6 %, 1/16).

Though the IPGT was out of normal range in all diabetic animals, coefficient of glucose assimilation was significantly higher in the ATG group (0.36 versus 0.12 mmol/L/min).

ATG therapy lead to a significant decrease of CD8+/CD4+ T-lymphocyte ratio in comparison to the control group; in splenocytes, a significant difference was detected only on day 7 (0.069 vs. 0.198); in lymph nodes decrease was found even on day 28 (0.21 vs. 0.51). Population of the regulatory T-cells was increased after ATG administration in comparison to the control group at day 7 (16,2% vs 10,8% in splenocytes; 20.7% vs. 10.3% in lymph node cells). However, the increase of the population of FoxP3+ cells was not durable.

Conclusions: ATG treatment of diabetic NOD mice showed only a partial metabolic improvement in already hyperglycemic NOD mice.

Supported by No.P304/10/0762.