[Tolerogenic dendritic cells form microchimerism in vivo in collagen-induced arthritis rats].

Objective To find evidence of microchimerism formation following infusion of tolerogenic dendritic cells (tDCs) into collagen-induced arthritis (CIA) rats. Methods Bone marrow-derived DC precursor cells were induced into tDCs by granulocyte-macrophage colony- stimulating factor (GM-CSF), interleukin 4 (IL-4) and nuclear factor-κB oligonucleotide decoy (NF-κB ODN decoy) and then infused into CIA rats after labeling with 1, 1' -octadecyl-3, 3, 3', 3' -tetramethyltricarbocyanine iodide (DiR). At 4 hours, 24 hours, 5 days, 10 days and 15 days after cell infusion, the fluorescence intensity and distribution were observed by in vivo imaging system of small animals. Rats were sacrificed on the 15th days to detect the fluorescence signals of the main organs. Results tDCs had high expression of OX62 and low expression of CD80 and CD86. The fluorescence signal was mainly concentrated in the chest, abdomen and left posterior joint, with the strongest fluorescence signal in the chest and abdomen at 24 hours and the strongest fluorescence signal in the left posterior joint at 5 days. Fluorescence could still be detected on the 15th days after cell infusion, and the left posterior joint of the diseased foot always maintained a strong fluorescence signal. In isolated organs, the fluorescence signals in the lung, liver, spleen and mesenteric lymph nodes were strong, and the kidney fluorescence signals was weak, and the heart had little fluorescence. Conclusion tDCs forms microchimerism in the diseased foot joints, lungs, liver, spleen, and mesenteric lymph nodes.

Tolerogenic dendritic cells alleviate collagen-induced arthritis by forming microchimerism and affecting the expression of immune checkpoint molecules.

Tolerogenic dendritic cells (tolDCs) have the potential to treat rheumatoid arthritis (RA) by inducing immune tolerance. However, the mechanism of intervention needs further study. Here, we investigated whether tolDCs formed microchimerism and their effect on the expression of immune checkpoint molecules after infusion of tolDCs into rats with collagen-induced arthritis (CIA). TolDCs derived from male SD rats were labeled with fluorescence and infused into female CIA rats. The fluorescence signals as well as the sex-determining region of Y-chromosome (SRY) gene revealed that tolDCs formed microchimerism in the mesenteric lymph nodes and ankle joints. We further explored the effect of tolDCs on the expression of immune checkpoint molecules in mesenteric lymph nodes and ankle joints. For stimulatory immune checkpoint molecules, the expressions of CD86 and CD40 decreased in mesenteric lymph nodes, and the expressions of CD40, CD40L, CD28, CD80, and CD86 also decreased in rat ankle joints. In contrast, the inhibitory immune checkpoint molecule PDL1 increased in mesenteric lymph nodes, and PD1, PDL1, and CTLA4 increased in ankle joints. In conclusion, our results suggested that intervention of tolDCs in CIA is associated with the formation of microchimerism and the effect on immune checkpoints.

Microscopic Observations on Form and Structure of the Worm Enchytraeus buchholzi (Clitellata: Enchytraeidae).

BACKGROUND: The worm Enchytraeus buchholzi is a new record species for Shaanxi, China, and a key pest on American ginseng Panax quinquefolium. To distinguish the species, the authors prepared its whole mounts and paraffin-embedded sections, and microscopically observed, photographed and measured. Besides, we conducted an experimental study on its DNA barcode.  RESULTS: Cells, tissues and organs related to nervous, digestive, circulatory, excretory and reproductive systems were found, photomicrographed and described, including: prostomium, peristomium, segments, clitellum, pygidium, lateral and ventral chaetae; brain, cranial nerves, sensory papillae, ventral nerve cord; pharyngeal pad and glands, retractor muscles and muscular bundles, peptonephridia, esophagus, intestine; dorsal, lateral, ventral and intestinal parietal vessels, coelomocytes, coelomic cavity; nephridia, chloragogen cells; ovaries, groups of germ cells with developing oocytes, mature eggs, spermathecae; testes, seminal vesicles, sperm funnels, penial bulbs. Their shapes and sizes were given, and functions discussed briefly. The visual effect of staining specimens with hematoxylin plus eosin ranked the first, and that with acetocarmine the second.  CONCLUSIONS: The supplementary and objective descriptions, with the microphotographs as forceful pieces of evidence, have expanded biological knowledge in aspects of the form, structure and function of the worm, which is helpful for professionals to recognize and understand this species and provide a solid basis for its integrated pest management.

[Tolerogenic dendritic cells alleviate joint inflammation and arthropathy via reducing Th1 and Th17 cell proportion in CIA rats].

Objective To investigate the effects of tolerogenic dendritic cells (tolDCs) induced by nuclear factor κB oligodeoxynucleotide decoy (NF-κB ODN decoy) on Th1 cells, Th2 cells, Th17 cells and regulatory T cells (Tregs) and the intervention effects on collagen-induced arthritis (CIA) rats. Methods SD female rats used to establish CIA rat models were divided into four groups, including a CIA model group, a bovine type II collagen-decoy-dendritic cell (Col2-decoy DC) treatment group, a blank control group, and a Col2-decoy DC control group. On the 20th days after the first immunization, the rats were injected with tolDCs via the tail vein, and the rats were sacrificed on the 7th weeks. The proportions of Th1 cells, Th2 cells, Th17 cells, and Tregs in the rat spleen were detected by flow cytometry. The ankle joint pathomorphological change was evaluated by HE staining, and the arthritis index (AI) was scored. Results Compared with the CIA model group, the Col2-decoy DC group had lower AI and milder ankle joint pathomorphological change. The percentages of Th1 cells and Th17 cells in the spleen CD4+ T cells decreased, while the percentages of Th2 cells and Tregs increased. Conclusion The treatment of tolDCs can alleviate the inflammation and arthropathy of CIA rats by reducing the proportion of Th1 and Th17 cells in CD4+ T cells.

DiR-labeled tolerogenic dendritic cells for targeted imaging in collagen- induced arthritis rats.

Tolerogenic dendritic cells (tolDCs) are immunosuppressive cells and play an important role in rheumatoid arthritis (RA) as immunotherapeutic tools. We aimed to investigate whether allogeneic tolDCs (allo-tolDCs) and autologous tolDCs (auto-tolDCs) had long-time tolerogenic potential in vivo and improve arthritis in collagen-induced arthritis (CIA) rats. TolDCs were induced by NF-κB Decoy ODN, and loaded with Bovine Type II collagen (CII- loaded tolDCs) and identified by flow cytometry, and labeled with DiR and injected into CIA rats. The biodistribution of DiR-labeled tolDCs was monitored by IVIS imaging at different time points. Major organs were harvested and analyzed by ex-in vivo cell imaging. The tolDCs were successfully constructed, along with expressing low levels of CD80 and CD86 compared to DCs. The fluorescent signals of all DiR (+) groups were observed at least 25 days, and as long as 35 days. DiR (+) CII- loaded allo-and auto-tolDCs at post injection mainly distributed in the chest and abdomen and gradually moved to limb joints over time. The allo- and auto-tolDCs decreased the expression of IFN-γ and IL-2 in CIA rats with different severity compared to CIA rats without tolDCs treatment, while significantly increased the expression of IL-4 and IL-10. Additionally, these tolDCs ameliorated the ankle joints injury in CIA rats with different severity. The both allo- and auto-tolDCs showed long-time tolerogenic potential in vivo and ameliorated arthritis in CIA rats with different severity.

Establishment of a low-tumorigenic MDCK cell line and study of differential molecular networks.

Influenza is an acute respiratory infection caused by the influenza virus, and vaccination against influenza is considered the best way to prevent the onset and spread. MDCK (Madin-Darby canine kidney) cells are typically used to isolate the influenza virus, however, their high tumorigenicity is the main controversy in the production of influenza vaccines. Here, MDCK-C09 and MDCK-C35 monoclonal cell lines were established, which were proven to be low in tumorigenicity. RNA-seq of MDCK-C09, MDCK-C35, and MDCK-W73 cells was performed to investigate the putative tumorigenicity mechanisms. Tumor-related molecular interaction analysis of the differentially expressed genes indicates that hub genes, such as CUL3 and EGFR, may play essential roles in tumorigenicity differences between MDCK-C (MDCK-C09 and MDCK-C35) and MDCK-W (MDCK-W73) cells. Moreover, the analysis of cell proliferation regulation-associated molecular interaction shows that downregulated JUN and MYC, for instance, mediate increased proliferation of these cells. The present study provides a new low-tumorigenic MDCK cell line and describes the potential molecular mechanism for the low tumorigenicity and high proliferation rate.

[Cooperative Protection of American Ginseng Seedlings by Applying Imidacloprid, Fludioxonil and Phoxim].

OBJECTIVE: To screen out an effective method of controlling pests on American ginseng(Panax quinquefolium). METHODS: The germinating seeds of the plant from two growers in Liuba County,Shaanxi Province,were collected and potted in pest-residing sandy soils indoors. Four pesticides (imidacloprid wettable powders, fludioxonil flowable concentrate for seed coating, chlorpyrifos granules and Pyrifos ∙ phoxim granules) in different modes and doses were applied, and their effects were assayed. RESULTS: Pests were largely enchytraeid(Enchytraeus bulbosus), root mite (Rhizoglyphus robini) and two root rot fungi(Cylindrocarpon destructans and Phytophthora cactorum), which could be transmitted by both seed and soil. The treatment of dressing or soaking seeds in mixed solution of imidacloprid 25WP and fludioxonil 2.5SD plus blending the pest-residing sandy soil with chlorpyrifos ∙ phoxim 5G displayed significant effects of both controlling pests and keeping stand of seedlings(P <0. 05); whereas each of the three pesticides exhibited a middle-class effect when applied alone, and chlorpyrifos l0G showed little effect when applied singly. CONCLUSION: The combined approach of seed- and soil-tteatments is able to efficiently reduce damages caused by seed- and soil-born pests, and become one optimal measure protecting seedlings,and is thus suggested to demonstrate and extend in the pests' infestation areas.