AGE-RELATED-CHANGES IN T-GAMMA-DELTA CELLS OF NOD MICE

T gamma delta cells have been reported to recognize both mycobacterial and human heat-shock proteins (HSP), and a possible role of 65 kDa HS P has been suggested also in the pathogenesis of insulin-dependent dia betes mellitus. The aim of this study was to investigate age-related c hanges of T gamma delta cells during diabetes development in non-obese diabetic (NOD) mice. Using FACS analysis relative numbers of T gamma delta(+) cells from thymus, blood and spleen were determined in 3-week -old nondiabetic, at onset of diabetes, and 1-week diabetic NOD mice a nd corresponding BALB/cJ controls. In comparison to BALB/cJ mice, high er values (2.4 +/- 0.2% vs. 1.1 +/- 0.1%) were found in the thymus of 3-week-old NOD mice (P < 0.01) as well as in spleens of 22-week-old li ttermates (1.1 +/- 0.1% vs. 0.6 +/- 0.1%, P < 0.01). In addition, a hi gher proportion of T gamma delta cells was observed in blood samples o f all age groups of NOD as compared to BALB/cJ mice, with values 3.5 /- 0.7% (P < 0.05) in 3-week-old to 4.4 +/- 0.9% and 3.7 +/- 0.3% (P < 0.01) in 16- and 22-week-old NOD littermates. Differences in TCR gamm a delta expression did not influence the whole CD3(+) subset of mononu clear cells. Thus, our results show relatively higher numbers of T gam ma delta cells in NOD mice and their increase in the periphery at onse t of diabetes and later may suggest that T gamma delta cells participa te in beta-cell destruction.