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Pets (cattle = 3, swine = 6, poultry = 3) were administered 4 doses from the antigen (1 mg/dosage in cattle, 0 This will allow a better understanding of the expected immunological effects in humans and the likely immunotoxicological consequences of any exaggerated pharmacology in FIH studies and beyond

The vessels of the islets were weakly positive for intercellular adhesion molecule 1 (ICAM-1), strongly positive for platelet endothelial cell adhesion molecule 1 (PECAM-1), and negative for vascular cell adhesion molecule-1 and P-selectin (13). of CD4 T cells into normal noninflamed islets. Thus, the anatomy of the islet of Langerhans permits the specific localization of diabetogenic T cells at a time when there is no inflammation in the islets. and Table 1). T cells were not found in the stroma at the time of their first identification in islets (Table S1). The same number of 3A9 TCR transgenic T cells transferred into IP-HEL did not localize to the islets of IP-HEL mice. To exclude effects of sublethal irradiation, activated 3A9 T cells were transferred into nonirradiated IP-HEL mice and found to be equally distributed as seen in sublethally irradiated recipients. Activated 3A9 T cells were not detected in the islets of sublethally irradiated B10.BR mice; that is, nonspecific localization was not observed at any time point (Fig. 1and Table 1). Unstimulated BDC T cells were not detected until 72 h and only in 20% of islets (Fig. 1and and and Table S2). The administration of the specific mAb (antiCI-Ak) partially reduced the localization to 33% of the islets (Fig. 2 and and Table S2), however. By 48 h, the islets were infiltrated equally and the difference in the number of T cells per islet was not statistically significant (Fig. 2and Table S2). Increasing the number of injections of anti-class II MHC mAb (1 d before T-cell transfer and 1 day after) gave the same results. Open in a separate window Fig. 2. Localization of CD4 T cells to islets during partial inhibition by anti-class II MHC mAb. ( 0.05 [not significant (ns)]; * 0.05; ** 0.01; *** 0.001; **** 0.0001. The localization of BDC T cells after 48 h was affected by the administration of the mAb to I-Ag7 but not by that of antiCI-Ak. In four experiments, the percentage of islets bearing CD4+ T cells decreased from 69% in untreated mice and 70% in mice treated with the irrelevant antiCI-Ak mAb to 27% in mice treated with antiCI-Ag7 mAb (Fig. 2 and and Table S3). By 72 h, all groups showed the same extent of T-cell infiltration (91C99%) (Fig. 2and Table S3). The partial inhibition of CD4 T-cell entry into the islet by class II MHC mAb suggested other contributing factors, such as a role for adhesion molecules. The vessels of the islets were weakly positive for intercellular adhesion molecule 1 (ICAM-1), strongly EBI-1051 positive for platelet endothelial cell adhesion molecule EBI-1051 1 (PECAM-1), and negative for vascular cell adhesion molecule-1 and P-selectin (13). Administering a blocking mAb to PECAM-1 did not affect T-cell localization into islets; however, a blocking CD3G mAb to ICAM-1 partially reduced the localization of activated 3A9 T cells transferred into IP-HEL mice to 41% at 24 h from control rat IgG of 71% (Fig. 3 and and 0.05 [not significant (ns)]; * 0.05; *** 0.001; **** EBI-1051 0.0001. Activated BDC T cells were transferred into sublethally irradiated NOD.ICAM-1+/+ or NOD.ICAM-1?/? mice (27) that received either antiCI-Ak or antiCI-Ag7 mAb (Fig. 3 and and promoter. Blood vessels were stained for PECAM-1). The area of physical contact was evident as fluorescence colocalization (Fig. 5and axis (top view) from a stack of 30 optical sections (0.5-m increments). (and reconstructions (side view) of same image stack (indicated as white lines). The image shows a DC dendrite inside the vessel (yellow merged color indicated by arrows). (= 108). Data were obtained from 17 different visualized fields from two experiments. (axes show the number of anti-class II beads per islet in B10.BR and NOD mice, respectively, representing compiled data from three independent experiments. ** 0.01; **** 0.0001. (test was used to determine the level of significant differences between samples and was plotted using GraphPad Prism 5 (GraphPad Software, Inc.). The following values were detected: **** 0.0001, *** 0.001, ** 0.01, * 0.05, and 0.05 (not significant). Median numbers of T cells per infiltrated islets in all experiments were obtained by including only islets containing infiltrating T cells. Supplementary Material Supporting Information: Click here to view. Acknowledgments.