Immunization with mycobacterial preparation such as Bacille Calmette-Guerin (BCG) or complete Freund's adjuvant (CFA) prevents the onset and recurrence of type 1 diabetes in non-obese diabetic (NOD) mice. In this study, we explored the mechanism underlying the down-regulation of diabetogenic T cells by BCG treatment. We found that the potential of splenocytes from BCG-immunized diabetic NOD mice to adoptively transfer diabetes was significantly impaired. BCG immunization sequentially induced the production of TNF-alpha, IFN-gamma and IL-4 by splenocytes, increased the expression of Fas(high) (Apo-1/CD95), Fas ligand (FasL, CD95L) and TNF receptor (TNFR) on T cells leading to T cell apoptosis. The primary role of IFN-gamma and TNF-alpha in BCG-immunotherapy was demonstrated by (i) reversing the immune regulatory effect of BCG by in vivo treatment with neutralizing anti-cytokine antibodies, (ii) inducing effect similar to BCG by treatment with these cytokines. We show that Fas and TNF are two pathways in BCG-induced apoptosis of diabetogenic T cells, since in vitro blocking FasL or TNFR1 with antibody reduced T cell apoptosis and increased T cell proliferative response. In addition, TNF-alpha and agonistic anti-Fas antibody had a synergistic effect on the in vitro apoptosis of diabetogenic T cells. Our results suggest that BCG down-regulates destructive autoimmunity by TNF-alpha/IFN-gamma-induced apoptosis of diabetogenic T cells through both Fas and TNF pathways. These studies provide a novel mechanism for blocking disease recurrence and immune modulating effect of BCG immunization in type 1 diabetes.

No abstract

The interaction of the TCR with the immunogenic peptide bound to MHC class II molecules leads to the activation of the CD4(+) T helper cells. T helper cells have been divided into two subsets, Th1 and Th2, on the basis of the cytokines secreted by them. Th1 cells which secrete IL-2, IFN-gamma and tumor necrosis factor-beta induce delayed-type hypersensitivity, while Th2 cells secreting IL-4, IL-5, IL-6 and IL-10 induce humoral immune response. However, the mechanism of selective activation of Th1 and Th2 cells in response to different antigens is not fully understood. In this study we examined the selective activation of Th1 and Th2 cells in response to strongly immunogenic synthetic peptides EYK(EYA)3, abbreviated as K3; EYK(EYA)4, abbreviated as K4; and EYKEYAAYA(EYA)2, abbreviated as K1A2. These peptides are recognized by H-2(d) T cells in the context of I-Ad, and are strongly cross-reactive in both T cell response and antibody response. The peptide K1A2 has very high affinity for I-Ad while K3 has a much lower affinity. K4 has affinity intermediate between K1A2 and K3. The peptide K1A2 induced Th1 and K3 induced Th2 cells in BALB/c mice as suggested by their cytokine profiles. K4 induced both Th1- and Th2-type cytokines. This was also confirmed by the analysis of both IgG1 and IgG2a responses in vivo. There was a shift toward a Th1-type cytokine profile when K3-primed T cells were challenged with K1A2 in vitro but K1A2-primed cells did not show any shift when challenged with K3. Immunization with higher doses of K3 shifted the response towards Th1 type, while immunization with lower doses of K1A2 did not shift the response toward Th2. We conclude that cells primed with high-affinity peptide are committed to differentiate into Th1 irrespective of the priming dose and affinity of challenge antigen. On the other hand, the differentiation of cells primed with low-affinity peptide depends upon the dose of immunization and binding affinity of the challenge antigen for MHC.

The present study using array-CGH analyses sought a deeper elucidation of the specific genomic alterations related to ULMS. The high resolution of array-CGH combined with human genome database would give a chance at identifying relevant target genes.

HNSCC patients show deterioration in swallowing function after CRT with normalcy of diet in maximum and eating in public least affected. Pre-CRT severity of dysphagia, weight loss> 10% and disease progression have significant correlation with higher swallowing function deterioration after CRT.