Language：English   Publishing type：Research paper (scientific journal)   Publisher：OXFORD UNIV PRESS  

If Bcl11b activity is compromised, CD4(+)CD8(+) double-positive ( DP) thymocytes produce a greatly increased fraction of innate CD8(+) single-positive ( SP) cells highly producing IFN-gamma, which are also increased in mice deficient of genes such as Itk, Id3 and NF-kappa B1 that affect TCR signaling. Of interest, the increase in the former two is due to the bystander effect of IL-4 that is secreted by promyelocytic leukemia zinc finger-expressing NKT and gamma delta T cells whereas the increase in the latter is cell intrinsic. Bcl11b zinc-finger proteins play key roles in T cell development and T cell-mediated immune response likely through TCR signaling. We examined thymocytes at and after the DP stage in Bcl11b(F/S826G) CD4cre, Bcl11b(F/+) CD4cre and Bcl11b(+/S826G) mice, carrying the allele that substituted serine for glycine at the position of 826. Here we show that Bcl11b impairment leads to an increase in the population of TCR alpha beta(high)CD44(high)CD122(high) innate CD8SP thymocytes, together with two different developmental abnormalities: impaired positive and negative selection accompanying a reduction in the number of CD8SP cells, and developmental arrest of NKT cells at multiple steps. The innate CD8SP thymocytes express Eomes and secrete IFN-gamma after stimulation with PMA and ionomycin, and in this case their increase is not due to a bystander effect of IL-4 but cell intrinsic. Those results indicate that Bcl11b regulates development of different thymocyte subsets at multiple stages and prevents an excess of innate CD8SP thymocytes.

DOI： 10.1093/intimm/dxu104

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

We investigated the expansion rate of CD4(+) memory T cells using a newly developed in vivo system. Neonatal thymectomy abrogates the subsequent production of T cells and induces autoimmune gastritis (AIG) by the activation of CD4(+) T cells; this disease was transferred into athymic nude mice through the inoculation of splenic CD4(+) memory T cells. The transferred CD4(+) T cells increased logarithmically in number during the first 2 months in the spleen of the recipients. The serial transfer of these splenocytes at two-month intervals revealed that the numbers of the AIG-transferable generations were inversely correlated with the age of the first AIG donors. The duration of the AIG-promoting capacity of CD4(+) T cells under continuous antigenic stimulation in vivo was approximately equivalent-one and a half years. These results indicate that there exists an intrinsic population doubling limit in memory CD4(+) T cells similar to that of self-renewing naive ones. (C) 2014 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.cellimm.2014.09.001

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：KOREAN SOCIETY BIOCHEMISTRY & MOLECULAR BIOLOGY  

Inoculation of mice with the murine NFSA cell line caused the formation of large tumors with necrotic tumor cores. FACS analysis revealed accumulations of CD11b(+) cells in the tumors. Microarray analysis indicated that the NFSA cells expressed a high level of the pro-inflammatory factor interleukin-18 (il-18), which is known to play a critical role in macrophages. However, little is known about the physiological function of IL-18-stimulated macrophages. Here, we provide direct evidence that IL-18 enhances the phagocytosis of RAW264 cells and peritoneal macrophages, accompanied by the increased expression of tumor necrosis factor (tnf-a), interleukin-6 (il-6) and inducible nitric oxide synthase (Nos2). IL-18-stimulated RAW264 cells showed an enhanced cytotoxicity to endothelial F-2 cells via direct cell-to-cell interaction and the secretion of soluble mediators. Taken together, our results demonstrate that tumor-derived IL-18 plays an important role in the phagocytosis of macrophages and that IL-18-stimulated macrophages may damage tumor endothelial cells.

DOI： 10.5483/BMBRep.2014.47.5.152

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：INT PRESS EDITING CENTRE INC  

Neonatal thynnectomy (NTx) induces autoimmune gastritis (AIG) in BALB/c mice, a model for human type A chronic atrophic gastritis, but not in DBA/2 mice and rarely in CDF1 mice (a hybrid of BALB/c and DBA/2 mice). The aim of this study was to clarify the mechanisms of AIG-resistance in mice bearing the dominant trait of DBA/2. Linkage groups associated with, and cells related to AIG resistance were examined with CDF1-BALB/c backcrosses. Intracellular staining and flow-cytometric bead array for several cytokines were performed on NTx BALB/c mice and NTx DBA/2-chimeric BALB/c mice receiving DBA/2-bone marrow cells. In NTx BALB/c mice, IFN-gamma-secreting CD4(+) T cells were increased, but not in NTx DBA/2 mice. Because V beta 6(+) T cell-bearing mice of half of their backcrosses developed AIG, but the other half of V beta 6(+) T cell-negative mice developed scarcely, resistance for AIG generation is associated with the presence of the MIs-1a locus on chromosome 1 in DBA/2 mice, which deletes V beta 6(+) T cells. NTx DBA/2-chimera BALB/c mice showed dominant production of IL-10 and resistance for AIG, although the deletion of V beta 6(+) T cells was found not to be a cause of AIG-resistance from MIs-1a locus segregation experiments. Although NTx DBA/2-chimeric BALB/c mice did not suffer from AIG, they brought immediate precursors of T cells for AIG. It is concluded that DBA/2 mice generate bone marrow-derived cells that produce anti-inflammatory cytokines to prevent the activation of AIG-T cells.

DOI： 10.1538/expanim.63.155

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Murine MS-K and NFSA cell lines formed tumor after inoculation into mouse and both cell lines expressed high level of vascular endothelial growth factor-A (vegf-A) and produced same level of VEGF-A. However, poor blood vessel formation, and necrosis was significantly observed in NFSA-tumor, contrary to well-developed blood vessel formation in MS-K tumor. The microarray analysis showed high expression of fibroblast growth factor-10 (fgf-10) in MS-K than NFSA. In this report, the role of fgf-10 on tumor growth was studied. MS-K enhanced more proliferation of endothelial cells by direct co-culture than NFSA, and rFGF10 supported the proliferation of HUVEC in combination with VEGF-A. fgf-10-knocked down MS-K, MS-K (fgf-10-KD), proliferated slower in vitro and the tumorigenicity of them was also slower than control. The blood vessel formation in these MS-K (fgf-10-KD) clones was reduced compared with the MS-K (normal). qPCR analysis showed the suppression of vegf-A, vegf-C and fgfr-1-expression in the MS-K (fgf-10-KD) clones. Taken together, these results indicated that FGF10, which was produced from tumor cells, was essential for the proliferation of tumor cell itself and also supports proliferation of endothelial cells. Thus, FGF10 plays an important role for tumor growth by both paracrine and autocrine manner.

DOI： 10.1111/gtc.12118

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Language：English  

Urodele amphibians are thought to have poorer immune responses than evolutionary more ancestral vertebrate classes, such as bony fish. We investigated skin graft rejection and transplantation immunity in Urodele amphibians, Japanese newts, and Asiatic salamanders, and compared these findings to those from transplants in several species of frogs. The skin grafts used in this study were either allogeneic or xenogeneic. The mean survival time of the first set of allografts at 20°C was approximately 60 days for chronic responses in Urodela and 20 days for acute responses in Anura. As the graft survival times of urodeles were significantly longer than those of anurans, even when urodeles were repeatedly grafted from identical donors, there appear to be substantial differences in transplantation immunity between Urodela and Anura. These slow responses in Urodela may not be accompanied by the expansion of cytotoxic T cells, as observed in fish and anuran species, which are known to have functional major histocompatibility complex (MHC)-class I systems. In our study, approximately five histo-incompatible immunogenic components were found to be involved in chronic responses in newts. Similar chronic responses were also observed in xenograft rejection in newts. In contrast, xenografts were rejected in frogs due to an accelerated acute response, possibly involving natural killer cells. Our findings that some anti-allogeneic components appear to be shared with xenogeneic components indicate that the diversification of the acquired immune system is poorly developed in Urodela.

DOI： 10.2108/zsj.30.577

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER TOKYO  

The thymus involutes after puberty, although the mechanism by which this process occurs remains poorly understood. The profile of thymic involution, which is inversely correlated with an increase in peripheral T cells, may indicate that the accumulation of T cells in the periphery is related to thymic atrophy. In this study, it was shown that the prevention of T cell generation delayed the initiation of thymic involution. The activation of T cells increased the serum concentration of glucocorticoid (GC) and thymic involution, which was completely prevented by adrenalectomy. In the adrenals of growing mice, the activity of the zona fasciculata, which produces GC, increased and plateaued by the weaning period; however, the zona reticularis (ZR), which produces dehydroepiandrosterone (DHEA) that has anti-GC actions, started to decline just before puberty. Thymic atrophy was preceded by the infiltration of activated T cells into the ZR and by the loss of ZR cells. Thus, T cells are involved in thymic involution, a process which was retarded by DHEA administration, through an increase in GC activity due to ZR cell-killing.

DOI： 10.1007/s12576-012-0194-y

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER ASSOC IMMUNOLOGISTS  

I kappa BNS has been identified as a member of the I kappa B family of NF-kappa B inhibitors, which undergoes induction upon TCR signaling. Mice carrying a targeted gene disruption of I kappa BNS demonstrate dysregulation of cytokines in T cells, macrophages, and dendritic cells. I kappa BNS mediates both positive and negative gene regulation, depending on individual cell type and/or cytokine. In this study, we demonstrate an additional role for I kappa BNS in the B cell lineage. B cells from I kappa BNS knockout ( KO) mice were impaired in proliferative responses to LPS and anti-CD40. IgM and IgG3 Igs were drastically reduced in the serum of I kappa BNS KO mice, although I kappa BNS KO B cells exhibited a higher level of surface IgM than that found in wild-type mice. Switching to IgG3 was significantly reduced in I kappa BNS KO B cells. The in vitro induction of plasma cell development demonstrated that progression to Ab-secreting cells was impaired in I kappa BNS KO B cells. In agreement with this finding, the number of Ab-secreting cells in the spleens of I kappa BNS KO mice was reduced and production of Ag-specific Igs was lower in I kappa BNS KO mice after influenza infection as compared with wild-type mice. Additionally, I kappa BNS KO mice lacked B1 B cells and exhibited a reduction in marginal zone B cells. Thus, I kappa BNS significantly impacts the development and functions of B cells and plasma cells. The Journal of Immunology, 2011, 187: 3942-3952.

DOI： 10.4049/jimmunol.1002109

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

The murine sarcoma cell line MS-K was previously established as a Ki-ras-positive cell line. Inoculation of this cell line under the flank of C3H/HeN mice results in the growth of large tumors with well-developed blood vessels within day 30 of transplantation without any metastasis because MS-K cells produce vascular endothelial growth factor (VEGF). To elucidate the role of VEGF in tumor formation in vivo, stable vegf-knockdown-MS-K clones were obtained using plasmid-based knockdown vectors. Interestingly, tumorigenesis was completely suppressed in a vegf-A-knockdown-MS-K clone [designated MS-K (A-KD)]. Proliferation and colony formation capacity of the MS-K (A-KD) cells in a semi-solid medium under low serum conditions was significantly lower than that of control MS-K (SCR) cells; however, the expression of vegf-receptor 1 (vegf-r-1) was not changed. Addition of the recombinant VEGF-A(165) partially restored the colony formation capacity of MS-K (A-KD) cells and caused the phosphorylation of VEGF-r-1 (Flt-1) in MS-K (Normal) cells. Furthermore, tumorigenicity of the vegf-r-1-knockdown-MS-K clone [designated MS-K (R1-KD)] had obviously delayed or strongly suppressed compared with the MS-K (Normal). These results indicate that Vascular endothelial growth factor-A, produced from MS-K, acts as a growth factor for MS-K cells itself and supports tumor formation in vivo by inducing the blood vessel formation.

DOI： 10.1111/j.1365-2443.2011.01513.x

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Nanotechnology-based antigen delivery has been developing as a vaccine strategy due to its dose-sparing and prolonged antigen presentation features. In the current study, we examined the feasibility of nanoparticle (NP)-mediated delivery of antigenic peptides to efficiently induce cytotoxic T lymphocyte responses against tumor-associated self-antigens in C57BL/6 mouse models. The biodegradable poly(e, L-lactide-co-glycolide) nanoparticle (PLGA-NP) carrying murine melanoma antigenic peptides, hgp100(25-33) and TRP2(180-188), were prepared by double emulsion method. Efficient uptake of PLGA-NP by murine dendritic cells was shown in vitro and in vivo, using NP labeled with the fluorescent dye DiD. Intradermal injection of peptide-loaded PLGA-NP into mice induced antigen-specific T cell responses more strongly than the peptides mixed with Freund's adjuvant. More importantly, vaccination with PLGA-NP carrying both TRP2(180-188) and a toll-like receptor 4 agonist, monophosphoryl lipid A, significantly delayed growth of subcutaneously inoculated B16 melanoma cells in a prophylactic setting. Furthermore, the anti-tumor activity of NP-mediated peptide vaccination was significantly augmented by combined treatment with interferon-gamma, which might prevent tumor escape through up-regulation of MHC class I expression on tumor cells. Our findings demonstrate the feasibility of NP-mediated antigen delivery for cancer immunotherapy, in particular when immune escape mechanisms of tumor cells are blocked simultaneously. (C) 2011 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.biomaterials.2011.01.067

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER ASSOC IMMUNOLOGISTS  

The alpha beta TCR has recently been suggested to function as an anisotropic mechanosensor during immune surveillance, converting mechanical energy into a biochemical signal upon specific peptide/MHC ligation of the alpha beta clonotype. The heterodimeric CD3 epsilon gamma and CD3 epsilon delta subunits, each composed of two Ig-like ectodomains, form unique side-to-side hydrophobic interfaces involving their paired G-strands, rigid connectors to their respective transmembrane segments. Those dimers are laterally disposed relative to the alpha beta heterodimer within the TCR complex. In this paper, using structure-guided mutational analysis, we investigate the functional consequences of a striking asymmetry in CD3 gamma and CD3 delta G-strand geometries impacting ectodomain shape. The uniquely kinked conformation of the CD3 gamma G-strand is crucial for maximizing Ag-triggered TCR activation and surface TCR assembly/expression, offering a geometry to accommodate juxtaposition of CD3 gamma and TCR beta ectodomains and foster quaternary change that cannot be replaced by the isologous CD3 delta subunit's extracellular region. TCR beta and CD3 subunit protein sequence analyses among Gnathostomata species show that the C beta FG loop and CD3 gamma subunit coevolved, consistent with this notion. Furthermore, restoration of T cell activation and development in CD3 gamma(-/-) mouse T lineage cells by interspecies replacement can be rationalized from structural insights on the topology of chimeric mouse/human CD3 epsilon delta dimers. Most importantly, our findings imply that CD3 gamma and CD3 delta evolved from a common precursor gene to optimize peptide/MHC-triggered alpha beta TCR activation. The Journal of Immunology, 2010, 185: 2951-2959.

DOI： 10.4049/jimmunol.1000732

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC  

Thymus-derived lymphocytes protect mammalian hosts against virus- or cancer-related cellular alterations through immune surveillance, eliminating diseased cells. In this process, T cell receptors (TCRs) mediate both recognition and T cell activation via their dimeric alpha beta, CD3 epsilon gamma, CD3 epsilon delta, and CD3 zeta zeta subunits using an unknown structural mechanism. Here, site-specific binding topology of anti-CD3 monoclonal antibodies (mAbs) and dynamic TCR quaternary change provide key clues. Agonist mAbs footprint to the membrane distal CD3 epsilon lobe that they approach diagonally, adjacent to the lever-like C beta FG loop that facilitates antigen (pMHC)-triggered activation. In contrast, a non-agonist mAb binds to the cleft between CD3 epsilon and CD3 gamma in a perpendicular mode and is stimulatory only subsequent to an external tangential but not a normal force (similar to 50 piconewtons) applied via optical tweezers. Specific pMHC but not irrelevant pMHC activates a T cell upon application of a similar force. These findings suggest that the TCR is an anisotropic mechanosensor, converting mechanical energy into a biochemical signal upon specific pMHC ligation during immune surveillance. Activating anti-CD3 mAbs mimic this force via their intrinsic binding mode. A common TCR quaternary change rather than conformational alterations can better facilitate structural signal initiation, given the vast array of TCRs and their specific pMHC ligands.

DOI： 10.1074/jbc.M109.052712

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DOI： 10.4049/jimmunol.179.3.1681

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER ASSOC IMMUNOLOGISTS  

CD3 epsilon gamma and CD3 epsilon delta are noncovalent heterodimers; each consists of Ig-like extracellular domains associated side-to-side via paired terminal beta-strands that are linked to individual subunit membrane proximal stalk segments. CD3 epsilon, CD3 gamma, and CD3 delta stalks contain the RxCxxCxE motif. To investigate the functional importance of a CD3 stalk and terminal beta-strand, we created a CD3 gamma double mutant CD3 gamma(C82S/C85S) and a CD3 gamma beta-strand triple mutant CD3 gamma(Q76S/Y78A/Y79A) for use in retroviral transduction of lymphoid progenitors for comparison with CD3 gamma wt. Although both mutant CD3 gamma molecules reduced association with CD3 epsilon in CD3 epsilon gamma heterodimers, CD3 gamma(Q76S/Y78A/Y79A) abrogated surface TCR expression whereas CD3 gamma(C82S/C85S) did not. Furthermore, CD3 gamma(C82S/C85S) rescued thymic development in CD3 gamma(-/-) fetal thymic organ culture. However, the numbers of double-positive and single-positive thymocytes after CD3 gamma(C82S/C85S) transduction were significantly reduced despite surface pre-TCR and TCR expression comparable to that of CD3 gamma(-/-) thymocytes transduced in fetal thymic organ culture with a retrovirus harboring CD3 gamma wt cDNA. Furthermore, double-negative thymocyte development was perturbed with attenuated double-negative 3/double-negative 4 maturation and altered surface-expressed CD3 epsilon gamma, as evidenced by the loss of reactivity with CD3 gamma N terminus-specific antisera. Single histidine substitution of either CD3 gamma stalk cysteine failed to restore CD3 epsilon gamma association and conformation in transient COS-7 cell transfection studies. Thus, CD3 gamma(C82) and CD3 gamma(C85) residues likely are either reduced or form a tight intrachain disulfide loop rather than contribute to a metal coordination site in conjunction with CD3 epsilon(C80) and CD3 epsilon(C83). The implications of these results for CD3 epsilon gamma and TCR structure and signaling function are discussed.

DOI： 10.4049/jimmunol.178.6.3668

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CENTER ACADEMIC PUBL JAPAN  

The deletion of CD4- and CD8-double-positive (DP) cells in the thymus after treatment with anti-CD3 antibodies has long been considered as a useful model for clonal deletion during T cell development, although it was reported that DP cell death was not observed in neonates where self-tolerance should be developing. We dealt with the cellular basis of this enigmatic phenomenon in this report. Due to the similar susceptibility to the antibody-treatment in vitro between neonatal and adult thymocytes, critical factors may be outside rather than within the thymus. Indeed, newborn thymus lobes transplanted into recipients of different ages showed an increased susceptibility to the thymo-toxicity as the age of the recipient increased. The thymo-toxicity seems to be based on the adrenal function of glucocorticoid (GC) synthesis, because administration of an inhibitor of GC synthesis significantly reduced the DP cell death by the antibody-treatment. Finally, adrenalectomy completely prevented DP cell death by anti-CD3 antibodies in adult mice. Therefore, the thymocyte death by anti-CD3 antibodies in vivo may not be due to the T cell-receptor mediated selection in the thymus.

DOI： 10.1111/j.1348-0421.2007.tb03896.x

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DOI： 10.4049/jimmunol.176.11.6812

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Fetal thymic organ cultures of N15-transgenic RAG-2(-/-) H-2(b) mice on normal, beta-2 microglobulin (beta2M)(-/-) or transporter associated with antigen processing (TAP-1)(-/-) MHCI-deficient backgrounds were used to examine differentiation of thymocytes bearing a TCR specific for a viral peptide bound to H-2K(b). Strong agonists mediate negative selection in all mice whereas weak agonists are positively selecting in beta2M(-/-) mice but negatively selecting on TAP-1(-/-) or normal backgrounds. Very weak agonists and very weak antagonists are generally without effect in beta2M(-/-) mice yet foster differentiation in TAP-1(-/-) animals. The 20-40-fold reduction in beta2M(-/-) thymic H-2Kb surface expression suggests that the avidity of the TCR for peptide-MHCI accounts for these differences, consistent with effects of TCR density and individual thymic-peptide abundance in peptide-MHC complexes. TCR-self-MHC interaction dominates K-b-based selection, subtly modulated by peptides as revealed by X-ray crystallography.

DOI： 10.1002/immu.200310011

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROCKEFELLER UNIV PRESS  

The asymmetric disposition of T cell receptor (TCR) Cbeta and Calpha ectodomains creates a cavity with a side-wall formed by the rigid Cbeta FG loop. To investigate the significance of this conserved structure, we generated loop deletion (betaDeltaFG) and betawt transgenic (tg) mice using the TCR P subunit of the N15 CTL. N15betawt and N15betaDeltaFG H-2(b) animals have comparable numbers of thymocytes in S phase and manifest developmental progression through the CD4(-)CD8(-) double-negative (DN) compartment. N15betaDeltaFG facilitates transition from DN to CD4(+)8(+) double-positive (DP) thymocytes in recombinase activating gene (RAG)-2(-/-) mice, showing that pre-TCR function remains. N15betaDeltaFG animals possess similar totwofold more CD8(+) single-positive (SP) thymocytes and lymph node T cells, consistent with enhanced positive selection. As an altered Vet repertoire observed in N15betaDeltaFG mice may confound the deletion's effect, we crossed N15alphabeta TCR tg RAG-2(-/-) with N15betaDeltaFG tg RAG-2(-/-) H-2(b) mice to generate N15alphabeta RAG-2(-/-) and N15alphabeta.betaDeltaFG RAG-2(-/-) littermates. N15alphabeta.betaDeltaFG RAG-2(-/-) mice show an 8-10-fold increase in DP thymocytes due to reduced negative selection, as evidenced by diminished constitutive and cognate peptide-induced apoptosis. Compared with N15alphabeta, N15alphabeta.betaDeltaFG T cells respond poorly to cognate antigens and weak agonists. Thus, the Cbeta FG loop facilitates negative selection of thymocytes and activation of T cells.

DOI： 10.1084/jem.20020119

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DOI： 10.1016/s1097-2765(02)00469-0

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：LIPPINCOTT WILLIAMS & WILKINS  

Background. The subcutaneous site has been regarded as a potential site for a bioartificial pancreas. Transplantation of islets, encapsulated by the development of diverse biocompatible materials and structural designs, can reverse hyperglycemia in diabetic recipients.
Methods. Approximately 750 Sprague-Dawley rat islets macroencapsulated in an agarose/poly (styrene sulfonic acid) mixed gel were implanted into a prevascularized subcutaneous site. The site was constructed by subcutaneous injection of basic fibroblast growth factor (bFGF) -impregnated gelatin microspheres in streptozotocin-induced C57BL/6 diabetic mice. Diabetic mice treated with bFGF-free gelatin microspheres and diabetic mice without any treatment undergoing the same subcutaneous transplantation were used as controls. After transplantation, non-fasting blood glucose, body weight, intraperitoneal glucose tolerance test, and histologic evaluations were processed.
Results. All the recipients undergoing the subcutaneous xenograft returned to normoglycemia within I week after transplantation. Eight of 10 recipients in the bFGF+ group maintained normoglycemia for a period of 38-101 days and gradually gained increase of body weight. Two of 10 recipients became hyperglycemic again when the grafts were respectively retrieved at days 31 and 63. Intraperitoneal glucose tolerance tests at month I and 2 revealed significant ameliorated glucose tolerance but a tendency to reduced glucose tolerance when compared respectively with those of the streptozotocin-induced diabetic mice and normal mice. Histologic examination revealed that islets within the retrieved grafts at days 31 and 63 were viable and intact; no fibrotic overgrowth was present around the surface of grafts.
Conclusions. A successfully prevascularized subcutaneous site could be constructed by a tissue bioengineering approach. Xenotransplantation of the agarose/poly (styrene sulfonic acid) mixed gel-based bioartificial pancreas in the prevascularized subcutaneous site could reverse diabetes in mice.

DOI： 10.1097/00007890-200201150-00023

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