TGF-beta1, expressed in the pancreatic islets, protects the nonobese diabetic (NOD) mouse from insulin-dependent diabetes mellitus (IDDM). The islet antigen-specific T cell response of ins-TGF-beta1 mice relied on different antigen-presenting cells (APC) from those used by NOD T cells. T cells from NOD mice utilized B cells to present islet antigen, whereas T cells from ins-TGF-beta1 mice utilized macrophages. In addition, the islet antigen-specific T cell repertoire of ins-TGF-beta1 mice was distinct and deviated toward an IL-4-producing Th2 phenotype. When ins-TGF-beta1 mice were treated with anti-iL-4 antibody, islet antigen-specific IFNGamma-producing Th1 cells were unleashed, and the incidence of diabetes increased to the level of NOD mice. This suggests active suppression of a diabetogenic T cell response. This study describes a novel mechanism in which expression of TGF-beta1 in the context of self-antigen shifts APC preference, deviating T cell responses to a Th2 phenotype, preventing IDDM.

The SNARE hypothesis proposes that synaptic vesicles dock at presynaptic membranes via interactions among the vesicular, integral membrane proteins VAMP (vesicle-associated membrane protein) and synaptotagmin and the target membrane proteins SNAP25 (synaptosome-associated protein with an Mr of 25 kDa) and syntaxin-1. Non-neuronal cells express isoforms of these proteins, believed to mediate secretory vesicle docking and/or fusion. Secretion in neuronal and non-neuronal systems differs in time course, Ca2+ dependence, and regulatory input. It is not known whether the non-neuronal protein isoforms form complexes akin to those of their neuronal counterparts. In this study, we defined the binding characteristics of three SNARE proteins: SNAP23, VAMP-2, and syntaxin-4. Binary, saturable interactions among all three partners (VAMP-2-syntaxin-4, VAMP-2-SNAP23, and SNAP23-syntaxin-4) were measured in vitro. Unlike its neuronal counterpart, SNAP23 did not potentiate VAMP-2 binding to its putative t-SNARE partner, syntaxin-4. The susceptibility of SNARE proteins to phosphorylation by exogenous kinases and their impact on binary interactions were explored. Syntaxin-4 was efficiently phosphorylated by casein kinase II (CKII) and cAMP-dependent protein kinase (PKA) (incorporating 0.8 and 3.9 mol of phosphate/mol of syntaxin-4, respectively), while syntaxin-1 was only strongly phosphorylated by CKII. Each of the syntaxin isoforms was weakly phosphorylated by protein kinase C (PKC) (<0.05 mol of phosphate/mol of syntaxin-4). Importantly, PKA but not casein kinase II phosphorylation of syntaxin-4 disrupted its binding to SNAP23. We hypothesize that PKA may modulate syntaxin-4-dependent SNARE complex formation to regulate exocytosis in non-neuronal cells.

The function of natural killer T (NKT) cells in the immune system has yet to be determined. There is some evidence that their defect is associated with autoimmunity, but it is still unclear how they play a role in regulating the pathogenesis of T cell–mediated autoimmune diseases. It was originally proposed that NKT cells could control autoimmunity by shifting the cytokine profile of autoimmune T cells toward a protective T helper 2 cell (Th2) type. However, it is now clear that the major function of NKT cells in the immune system is not related to their interleukin (IL)-4 secretion. In fact, NKT cells mainly secrete interferon (IFN)-γ and, activated in the presence of IL-12, acquire a strong inflammatory phenotype and cytotoxic function.

Adoptive immunotherapy can induce sustained therapeutic effects in some cancers. Antitumor T cell grafts are often individually prepared in vitro from autologous T cells, which requires an intensive workload and increased costs. The quality of the generated T cells can also be variable, which affects the therapy's antitumor efficacy and toxicity. Standardized production of antitumor T cell grafts from third-party donors will enable widespread use of this modality if allogeneic T cell responses are effectively controlled. Here, we generated HLA class I, class II, and T cell receptor triple knockout (tKO) T cells by simultaneous knockout of the B2M, CIITA and TRAC genes through Cas9/sgRNA ribonucleoprotein electroporation. Although HLA deficient T cells were targeted by natural killer cells, they persisted better than HLA sufficient T cells in the presence of allogeneic peripheral blood mononuclear cells (PBMC) in immunodeficient mice.When transduced with a CD19 chimeric antigen receptor (CAR) and stimulated by tumor cells, tKO CAR-T cells persisted better when cultured with allogeneic PBMC compared with TRAC and B2M double-knockout T cells. The CD19 tKO CAR-T cells did not induce graft-versus-host disease, but retained antitumor responses. These results demonstrated the benefit of HLA class I, class II, and TCR deletion in enabling allogeneic-sourced T cells to be used for off-the-shelf adoptive immunotherapy. SynopsisAntitumor T cell grafts concurrently ablated of HLA class I, class II, and TCR molecules evade allogeneic T cell responses and can be used as a universal T cell source for adoptive cancer immunotherapy.

People with Muscular Dystrophy (MD) and certain other muscular and nervous system disorders lose their gross motor control while retaining fine motor control. The result is that they lose the ability to move their wrists and arms, and therefore their ability to operate a mouse and keyboard. However, they can often still use their fingers to control a pencil or stylus, and thus can use a handheld computer such as a Palm. We have developed software that allows the handheld to substitute for the mouse and keyboard of a PC, and tested it with four people (ages 10, 12, 27 and 53) with MD. The 12-year old had lost the ability to use a mouse and keyboard, but with our software, he was able to use the Palm to access email, the web and computer games. The 27-yearold reported that he found the Palm so much better that he was using it full-time instead of a keyboard and mouse. The other two subjects said that our software was much less tiring than using the conventional input devices, and enabled them to use computers for longer periods. We report the results of these case studies, and the adaptations made to our software for people with disabilities.

No abstract

In the presence of interferon-gamma (IFN-gamma), pancreatic ductal epithelial cells grow continuously, and islets undergo neogenesis. To determine whether these new islets are derived from conventional precursors, we tested whether IFN-gamma can complement the loss of transcription factors known to regulate pancreatic development. We analyzed the effect of a transgene on lethality in mice lacking the transcription factors Pax4, Pax6, or Pdx-1, by intercrossing such mice with transgenic mice whose pancreatic cells make IFN-gamma (ins-IFN-gamma mice). However, IFN-gamma expression did not rescue these mice from the lethal mutations, because no homozygous knockout mice carrying the IFN-gamma transgene survived, despite the survival of all other hemizygous gene combinations. This outcome demonstrates that the pathway for IFN-gamma regeneration requires the participation of Pax4, Pax6, and Pdx-1. We conclude that the striking islet regeneration observed in the ins-IFN-gamma NOD strain is regulated by the same transcription factors that control initial pancreatic development.

Recent reports have shown that B cells play a key role in the pathogenesis of T cell-mediated autoimmune diseases such as insulin-dependent diabetes mellitus (IDDM) in nonobese diabetic mice (NOD). We have investigated the role of B lymphocytes as APCs in the generation of autoreactive T cell responses by comparing spontaneous responses to self Ags in B cell-deficient and wild-type NOD mice. We determined that B cell-deficient mice had no spontaneous responses to 65-kDa glutamate decarboxylase (GAD65), its immunodominant peptides, and the 60-kDa heat shock protein. In contrast, these Ags are able to induce proliferative responses in the splenocyte cultures of B cell-positive NOD mice. However, T cells from B-deficient mice conserved the ability to respond to nonself Ags and mitogens. The Ag-presenting function of B cells was pivotal in the autoimmune response, since the proliferation of wild-type splenocytes to GAD65 was completely inhibited by blocking the surface Ig-mediated capture of the protein Ag by B cells. Responses to immunodominant GAD65 peptides were also absent in B cell-deficient NOD mice, suggesting that B cells are crucial with regard to the diversification of the autoimmune response to various self epitopes. We believe our results represent strong evidence that B cells are required as APCs to generate pathogenic autoimmune T cell responses and provide a direct correlation between the protection from autoimmune diabetes previously reported in B cell-deficient NOD mice and the lack of anti-GAD65 and anti-heat shock protein 60 T cell responses in these mice.