IL-12p40-overexpressing immature dendritic cells induce T cell hyporesponsiveness in vitro but accelerate allograft rejection in vivo: role of NK cell activation and interferon-gamma production

Infusion of genetically modified dendritic cells (DC) expressing immunosuppressive molecules is a potential therapy for organ rejection. IL-12p70, a cytokine produced mainly by DC and macrophages, consists of two subunits, p40 and p35. IL-12p70 is an activator of T cells, while the IL-12p40 subunit serves as a natural antagonist for IL-12p70 action. The primary aim of this study was to evaluate the effect of IL-12p40 gene-modification on both the T-cell stimulatory activity of immature DC (imDC) and their ability to prolong cardiac allograft survival. IL-12p40 gene-modified imDC (DC-p40) exhibited a phenotype characteristic of imDC and displayed impaired T-cell allostimulatory ability in vitro. However, to our surprise, for murine vascularized heterotopic heart transplantation (HHT), administration of donor-derived DC-p40 7 days prior to transplantation did not prolong allograft survival but instead significantly exacerbated cardiac allograft rejection. Further study showed that DC-p40 augmented NK cell activity both in vitro and in vivo and enhanced interferon-gamma (IFN-gamma) production in vivo, which might be due to the increased IL-23 production by DC-p40. Our data suggested that although IL-12p40 gene-modified immature DC can induce T cell hyporesponsiveness in vitro, their ability to activate NK cells and induce IFN-gamma production counterbalances this, exacerbating cardiac allograft rejection. The unexpected effects of DC-p40 limit their value in promoting allograft survival in vivo and likely reflect the complexity of IL-12p40 biology.     

KOCH三角的解剖

本实验解剖了110例人心标本(成人70、儿童40)的Koch三角区,观察和测量了房室结的形态、大小、毗邻和标志。房间隔及冠状窦口上、下方均有肌束连于房室结。Todaro腱在儿童多全部为腱性;在成人,其后部为肌性。三角区的深面为左、右心房壁和室间隔顶所构成的锥形间隙,其内为进入房室结区的血管和神经。根据构成不同,可将三角区分为5个区,即前上角的纤维支架区和房室结区,其余部分自上向下分别为房间隔区、右房壁区和室间隔区。本文还讨论了这些形态结构的功能及外科意义。     

Identification of a new HLA-B*56 variant, B*5614

In this report, the novel allele B*5614 is presented. The allele was identified in a Chinese individual by sequence-based typing. HLA-B*5614 differs from B*5608 by a single nucleotide at position 277G-->C in exon 2. This results in an amino acid change from Gly to Arg at codon 93.     

Cocrystallization of an immunoglobulin light chain dimer with bis(dinitrophenyl) lysine: tandem binding of two ligands, one with and one without accompanying conformational changes in the protein

Previous studies showed that the Mcg dimer of immunoglobulin light chains bound bis(dinitrophenyl)lysine both in trigonal crystals and in solution. On prolonged storage in ammonium sulfate, mixtures of ligand and protein produced small trigonal cocrystals in low frequency. These crystals were nearly isomorphous with those of the unliganded dimer in which the subunits were covalently linked by an interchain disulfide bond. By difference Fourier analyses at 3.5 A resolution and subsequent crystallographic refinement, the cocrystals were found to contain molecules with two ligands aligned in tandem along the interface of the variable (V) domains of the protein. One ligand molecule adopted an almost fully extended conformation, with the epsilon-DNP ring situated near the floor, the alpha-carboxyl group directed toward the solvent at the entry, and the alpha-DNP ring outside the rim of the main cavity. As if architecturally designed, the ligand was located symmetrically between the two domains in an orientation that was compatible with both the unaltered structure of the cavity lining and with the known crystal packing interactions of neighboring protein molecules. The second ligand molecule in the cocrystal lodged in the deep pocket immediately under the floor of the main cavity. The ligand adopted a very compact conformation with the two DNP rings roughly antiparallel to each other. This molecule appeared to be semi-permanently sequestered in the pocket since it could not be dislodged by exhaustive perfusion with ammonium sulfate crystallizing media. Relative to its volume in the native dimer, the pocket was expanded to accommodate the oversized ligand. Within a single protein molecule, therefore, two types of binding of a flexible ligand were observed, one with and one without accompanying conformational changes in the protein. The number of cocrystals which could be produced was markedly increased if the interchain disulfide bond between the Mcg monomers was first reduced and alkylated.     

Increase in the number of detectable preoptic glutamic acid decarboxylase 67-immunoreactive cells in immature male rats

Gonadotropin-releasing hormone (GnRH) neurons are mainly located in the anterior preoptic area (aPOA) and gamma-aminobutyric acid (GABA) is known as a potent regulator of the GnRH neurons. To examine the development of the GABAergic system in the aPOA, immunocytochemistry of glutamic acid decarboxylase 67 (GAD(67)) was performed in immature (postnatal d16, d25 and d30) and mature (postnatal 10 weeks) male rats. All immunocytochemical procedures were simultaneously performed. In the lateral part of the aPOA, the detectable number of GAD(67)-immunoreactive cells was small in the d16 group, but significantly increased in the d25, d30 and mature groups, up to 2.7, 4.8 and 5.7 times the number in the d16 group, respectively. In the diagonal band of Broca (DBB), the number was also small in the d16 group, and significantly increased in the d25, d30 and mature groups upto 1.8, 2.2 and 2.8 times the number in the d16 group, respectively. However, in the cingulate cortex, no significant developmental change was observed. These results suggest that the development of the GABAergic system in the lateral aPOA and the DBB occurs before sexual maturation of male rats.     

Splice variants of the relaxin and INSL3 receptors reveal unanticipated molecular complexity

LGR7 and LGR8 are G protein-coupled receptors that belong to the leucine-rich repeat-containing G-protein coupled receptor (LGR) family, including the thyroid-stimulating hormone (TSH), LH and FSH receptors. LGR7 and LGR8 stimulate cAMP production upon binding of the cognate ligands, relaxin and insulin-like peptide 3 (INSL3), respectively. We cloned several novel splice variants of both LGR7 and LGR8 and analysed the function of four variants. LGR7.1 is a truncated receptor, including only the N-terminal region of the receptor and two leucine rich repeats. In contrast, LGR7.2, LGR7.10 and LGR 8.1 all contain an intact seven transmembrane domain and most of the extracellular region, lacking only one or two exons in the ectodomain. Our analysis demonstrates that although LGR7.10 and LGR8.1 are expressed at the cell surface, LGR7.2 is predominantly retained within cells and LGR7.1 is partially secreted. mRNA expression analysis revealed that several variants are co-expressed in various tissues. None of these variants were able to stimulate cAMP production following relaxin or INSL3 treatment. Unexpectedly, we did not detect any direct specific relaxin or INSL3 binding on any of the splice variants. The large number of receptor splice variants identified suggests an unforeseen complexity in the physiology of this novel hormone-receptor system.     

下颌骨的应力迹线与骨小梁构筑的关系

根据下頜光弹的等倾线图,描绘出主应力迹线规迹。在下颌侧位X线照片和去除唇侧及颊侧密质骨板的标本上,观察骨密质和松质的配布,以及骨小梁的排列和方向,试行探讨骨小梁方向与主应力迹线的关系。用光弹法求得的主应力迹线有两个系列:S_1系在下颌体近水平方向,在下颌支近垂直方向分布;S_2系力线与S_1系诸力线呈正交。在标本和X线照片上,主应力迹线规迹不同程度地在骨小梁的排列上有所反映。