Detection of human parvovirus B19 in papillary thyroid carcinoma.

To evaluate whether parvovirus B19, a common human pathogen, was also involved in papillary thyroid carcinoma (PTC), 112 paraffin-embedded thyroid specimens of benign nodules, papillary, medullary and follicular carcinomas, and normal controls were examined for B19 DNA and capsid protein by nested PCR, in situ hybridisation (ISH) and immunohistochemistry (IHC). The expression of the nuclear factor-kappaB (NF-kappaB) was investigated by IHC. The results showed B19 DNA commonly exists in human thyroid tissues; however, there were significant differences between PTC group and normal controls, and between PTC and nonneoplastic adjacent tissues (P<0.001). The presence of viral DNA in PTC neoplastic epithelium was confirmed by laser-capture microdissection and sequencing of nested PCR products. B19 capsid protein in PTC group was significantly higher than that of all the control groups and nonneoplastic adjacent tissues (P

Programmed death-1 ligands-transfected dendritic cells loaded with glutamic acid decarboxylase 65 (GAD65) inhibit both the alloresponse and the GAD65-reactive lymphocyte response.

Type 1 diabetes (T1D) is due to a loss of immune tolerance to islet antigens, such as glutamic acid decarboxylase 65 (GAD65), for which islet transplantation is a promising therapy. Therefore, the generation of tolerance aiming at both alloantigen and GAD65 will help therapeutic intervention greatly in T1D. In this study, we tested the effect of programmed death-1 ligands (PD-L1)-transfected dendritic cells (DC) loaded with GAD65 on the alloresponse and GAD65-reactive lymphocyte response. The DC2.4 cell line was transfected with PD-L1 and co-cultured with GAD65. BALB-c mice were primed, respectively, by intraperitoneal injection with GAD65, PD-L1-transfected- or non-transfected DC (PD-L1/DC or DC), and PD-L1-transfected- or non-transfected DC loaded with GAD65 (PD-L1/DC/GAD65 or DC/GAD65). Splenocytes of treated mice were isolated and restimulated in vitro with GAD65 or the various DC populations above being used as stimulators, respectively. In the mixed lymphocyte reaction, DC/GAD65 were able to stimulate both allogeneic and GAD65-reactive lymphocytes. However, PD-L1/DC/GAD65 were poorer than DC/GAD65 at activating the GAD65-reactive lymphocyte response. Further, although PD-L1/DC could inhibit the alloresponse, PD-L1/DC/GAD65 were more effective at down-regulating the GAD65-reactive lymphocyte response. More importantly, PD-L1/DC/GAD65-primed lymphocytes exhibited the weakest proliferation when again restimulated in vitro by PD-L1/DC/GAD65. Additionally, PD-L1/DC/GAD65 down-regulated interferon-gamma and up-regulated interleukin-10 production by activated lymphocytes. Therefore, combined stimulation in vivo and in vitro by PD-L1/DC/GAD65 could inhibit both the alloresponse and the GAD65-reactive lymphocyte response, which may contribute to controlling diabetes and islet transplant rejection.

The immunosuppressive and protective ability of glucose-regulated protein 78 for improvement of alloimmunity in beta cell transplantation.

An insulinoma cell line, NIT-1, transfected with glucose-regulated protein 78 (GRP78) was established, namely NIT-GRP78, and used to study the immunosuppressive and protective ability of GRP78. In extended cytotoxic T lymphocyte (CTL) killing assay, NIT-1-primed lymphocytes were more cytotoxic in killing beta cells than NIT-GRP78-primed lymphocytes. Severe necrosis was observed only when the NIT-1-primed lymphocytes were cultured with NIT-1 beta cells, but not with NIT-GRP78 cells. In addition, an increase of interleukin (IL)-4 secretion from beta cell-primed splenocytes when GRP78 presence was observed in cytokine enzyme-linked immunosorbent assay (ELISA). Diabetic mice reached normoglycaemia promptly and gained weight after transplantation of either NIT-1 or NIT-GRP78 cells. However, the recipient mice transplanted with NIT-GRP78 cells lived much longer than those recipients transplanted with NIT-1 cells, which was due apparently to prolonged insulin production by the transplanted NIT-GRP78 cells. In fact, we observed a significant increase of insulin concentration after glucose stimulation of diabetic mice received NIT-GRP78 cells at day 7 post-transplantation. From the results we propose that GRP78 could have a dual function in both protecting NIT-1 cells from CTL-mediated lysis and stimulating a population of T helper 2 cells to down-regulate the immune response to the transplanted beta cells.