Differential dependence on nuclear factor‐κB‐inducing kinase among natural killer T‐cell subsets in their development

Natural killer T cells (NKT cells) are comprised of several subsets. However, the possible differences in their developmental mechanisms have not been fully investigated. To evaluate the dependence of some NKT subpopulations on nuclear factor-κB-inducing kinase (NIK) for their generation, we analysed the differentiation of NKT cells, dividing them into subsets in various tissues of alymphoplasia (aly/aly), a mutant mouse strain that lacks functional NIK. The results indicated that the efficient differentiation of both invariant NKT (iNKT) and non-iNKT cells relied on NIK expression in non-haematopoietic cells; however, the dependence of non-iNKT cells was lower than that of iNKT cells. Especially, the differentiation of CD8⁺ non-iNKT cells was markedly resistant to the aly mutation. The proportion of two other NKT cell subsets, NK1.1⁺ γδ T cells and NK1.1⁻ iNKT cells, was also significantly reduced in aly/aly mice, and this defect in their development was reversed in wild-type host mice given aly/aly bone marrow cells. In exerting effector functions, NIK in NKT-αβ cells appeared dispensable, as NIK-deficient NKT-αβ cells could secrete interleukin-4 or interferon-γ and exhibit cytolytic activity at a level comparable to that of aly/+ NKT-αβ cells. Collectively, these results imply that the NIK in thymic stroma may be critically involved in the differentiation of most NKT cell subsets (although the level of NIK dependence may vary among the subsets), and also that NIK in NKT-αβ cells may be dispensable for their effector function.     

Therapeutic envelope vaccination in combination with antiretroviral therapy temporarily rescues SIV‐specific CD4+ T‐cell‐dependent natural killer cell effector responses in chronically infected rhesus macaques

Natural killer (NK) cells are essential components of the immune system, and due to their rapid response potential, can have a great impact during early anti‐viral immune responses. We have previously shown that interleukin‐2‐dependent NK and CD4⁺ T‐cell co‐operative immune responses exist in long‐term simian immunodeficiency virus (SIV) ‐infected controlling macaques and can be rescued in SIV‐infected non‐controlling macaques by a short course of antiretroviral therapy (ART). Given that co‐operative responses may play an important role in disease prevention and therapeutic treatment, in the present study we sought to determine if these responses can be enhanced in chronically SIV‐infected macaques by vaccination with a single‐dose of envelope protein given during ART. To this end, we treated 14 chronically SIV‐infected macaques with ART for 11 weeks and gave 10 of these macaques a single intramuscular dose of SIV gp120 at week 9 of treatment. ART significantly decreased plasma and mucosal viral loads, increased the numbers of circulating CD4⁺ T cells in all macaques, and increased T‐cell‐dependent envelope‐ and gag‐specific interferon‐γ and tumour necrosis factor‐α production by circulatory CD56⁺ NK cells. The therapeutic envelope immunization resulted in higher envelope‐specific responses compared with those in macaques that received ART only. Functional T‐cell responses restored by ART and therapeutic Env immunization were correlated with transiently reduced plasma viraemia levels following ART release. Collectively our results indicate that SIV‐specific T‐cell‐dependent NK cell responses can be efficiently rescued by ART in chronically SIV‐infected macaques and that therapeutic immunization may be beneficial in previously vaccinated individuals.     

Interleukin‐15‐activated natural killer cells kill autologous osteoclasts via LFA‐1, DNAM‐1 and TRAIL,and inhibit osteoclast‐mediated bone erosion in vitro

Osteoclasts reside on bone and are the main bone resorbing cells playing an important role in bone homeostasis, while natural killer (NK) cells are bone‐marrow‐derived cells known to play a crucial role in immune defence against viral infections. Although mature NK cells traffic through bone marrow as well as to inflammatory sites associated with enhanced bone erosion, including the joints of patients with rheumatoid arthritis, little is known about the impact NK cells may have on mature osteoclasts and bone erosion. We studied the interaction between human NK cells and autologous monocyte‐derived osteoclasts from healthy donors in vitro. We show that osteoclasts express numerous ligands for receptors present on activated NK cells. Co‐culture experiments revealed that interleukin‐15‐activated, but not resting, NK cells trigger osteoclast apoptosis in a dose‐dependent manner, resulting in drastically decreased bone erosion. Suppression of bone erosion requires contact between NK cells and osteoclasts, but soluble factors also play a minor role. Antibodies masking leucocyte function‐associated antigen‐1, DNAX accessory molecule‐1 or tumour necrosis factor‐related apoptosis‐inducing ligand enhance osteoclast survival when co‐cultured with activated NK cells and restore the capacity of osteoclasts to erode bone. These results suggest that interleukin‐15‐activated NK cells may directly affect bone erosion under physiological and pathological conditions.     

Age Progression of Neuropathological Markers in the Brain of the Chilean Rodent Octodon degus,a Natural Model of Alzheimer's Disease

Alzheimer's disease (AD) is the most common neurodegenerative disorder and the leading cause of age‐related dementia worldwide. Several models for AD have been developed to provide information regarding the initial changes that lead to degeneration. Transgenic mouse models recapitulate many, but not all, of the features of AD, most likely because of the high complexity of the pathology. In this context, the validation of a wild‐type animal model of AD that mimics the neuropathological and behavioral abnormalities is necessary. In previous studies, we have reported that the Chilean rodent Octodon degus could represent a natural model for AD. In the present work, we further describe the age‐related neurodegeneration observed in the O. degus brain. We report some histopathological markers associated with the onset progression of AD, such as glial activation, increase in oxidative stress markers, neuronal apoptosis and the expression of the peroxisome proliferative‐activated receptor γ coactivator‐1α (PGC‐1α). With these results, we suggest that the O. degus could represent a new model for AD research and a powerful tool in the search for therapeutic strategies against AD.     

心理护理对足月初产妇分娩过程的影响

目的：观察心理护理干预是否可减轻产妇分娩痛苦、缩短产程、提高自然分娩率,提高母乳喂养率。方法选择我院2011年6月1日至2011年12月31日住院的322例初产妇,随机分为对照组和心理护理组,每组161例。两组产妇均给予产科常规护理;心理护理组进行产前、产中和产后心理护理干预。结果对足月初产妇进行心理护理干预可减轻分娩痛、缩短分娩时间、提高顺产和母乳喂养率。结论足月初产妇在进行心理护理干预后,有利于提高初产妇分娩质量,帮助产妇更快恢复健康,值得广泛推广。     

Differential loss of natural killer cell activity in patients with acute myocardial infarction and stable angina pectoris

Background: To evaluate the activity of natural killer cells through their inhibitory and activating receptors and quantity in peripheral blood mononuclear cells extracted from patients with acute myocardial infarction, stable angina pectoris and the controls. Methods: 100 patients with myocardial infarction, 100 with stable angina, and 20 healthy volunteers were recruited into the study. 20 randomly chosen people per group were examined for the whole human genome microarray analysis to detect the gene expressions of all 40 inhibitory and activating natural killer cell receptors. Flow cytometry analysis was applied to all 200 patients to measure the quantity of natural killer cells. Results: In myocardial infarction group, the mRNA expressions of six inhibitory receptors KIR2DL2, KIR3DL3, CD94, NKG2A, KLRB1, KLRG1, and eight activating receptors KIR2DS3, KIR2DS5, NKp30, NTB-A, CRACC, CD2, CD7 and CD96 were significantly down-regulated (P<0.05) compared with both angina patients and the controls. There was no statistical difference in receptor expressions between angina patients and control group. The quantity of natural killer cells was significantly decreased in both infarction and angina patients compared with normal range (P<0.001). Conclusions: The significant mRNAs down-regulation of several receptors in myocardial infarction group and reduction in the quantity of natural killer cells in both myocardial infarction and angina patients showed a quantitative loss and dysfunction of natural killer cells in myocardial infarction patients.     

Culture and properties of adipose-derived mesenchymal stem cells: characteristics in vitro and immunosuppression in vivo

Objective: To compare the two sources of adipose and bone marrow derived mesenchymal stem cells (BMSCs and AMSCs) in immune regulation and to evaluate the therapeutic effects of AMSCs on Con A induced hepatitis and the possible mechanism involved in it. Methods: We isolated bone marrow and adipose derived mesenchymal stem cells respectively and compared their differences on T lymphocyte activation, proliferation and suppression. We also test the anti-apoptosis ability of AMSCs on LO2 cell line. The effects of intravenous infusion of AMSCs on liver damage were also tested and we detected donor AMSCs in liver of recipient and their effects on the activity of intrahepatic NKT cells. Results: BMSCs and AMSCs were similar in cell phenotype and the difference existed only in the expression of CD106. The results showed that the capacity of suppressing T cells proliferation and activation was weakened in AMSCs. AMSCs ameliorated liver damage and this effect was time and dose dependent. We detected donor AMSCs in liver of recipient which suggested tissue damage could be a clue for AMSCs migration. We also found AMSCs suppress the activity of intrahepatic NKT cells, but this suppress effects was not restricted in liver only, but the whole body. Conclusion: Cell origin and abundance are decisive factors in stem cells applications and with the same premise of AMSCs and BMSCs, adipose tissue is a more promising origin source of stem cells. The immunoregulatory features of MSCs might play an important role in various MSCs cellular therapies.     

A cross‐sectional multicenter study of osteogenesis imperfecta in North America – results from the linked clinical research centers

Osteogenesis imperfecta (OI) is the most common skeletal dysplasia that predisposes to recurrent fractures and bone deformities. In spite of significant advances in understanding the genetic basis of OI, there have been no large‐scale natural history studies. To better understand the natural history and improve the care of patients, a network of Linked Clinical Research Centers (LCRC) was established. Subjects with OI were enrolled in a longitudinal study, and in this report, we present cross‐sectional data on the largest cohort of OI subjects (n = 544). OI type III subjects had higher prevalence of dentinogenesis imperfecta, severe scoliosis, and long bone deformities as compared to those with OI types I and IV. Whereas the mean lumbar spine area bone mineral density (LS aBMD) was low across all OI subtypes, those with more severe forms had lower bone mass. Molecular testing may help predict the subtype in type I collagen‐related OI. Analysis of such well‐collected and unbiased data in OI can not only help answering questions that are relevant to patient care but also foster hypothesis‐driven research, especially in the context of ‘phenotypic expansion’ driven by next‐generation sequencing.