Xenogeneic Cells Research Articles

Engineering a Tumor Microenvironment-Mimetic Niche for Tissue Regeneration with Xenogeneic Cancer Cells.

The insufficient number of cells suitable for transplantation is a long‐standing problem to cell‐based therapies aimed at tissue regeneration. Xenogeneic cancer cells (XCC) may be an alternative source of therapeutic cells, but their transplantation risks both immune rejection and unwanted spreading. In this study, a strategy to facilitate XCC transplantation is reported and their spreading in vivo is confined by constructing an engineering matrix that mimics the characteristics of tumor microenvironment. The data show that this matrix, a tumor homogenate‐containing hydrogel (THAG), successfully creates an immunosuppressive enclave after transplantation into immunocompetent mice. XCC of different species and tissue origins seeded into THAG survive well, integrated with the host and developed the intrinsic morphology of the native tissue, without being eliminated or spreading out of the enclave. Most strikingly, immortalized human hepatocyte cells and rat β‐cells loaded into THAG exert the physiological functions of the human liver and rat pancreas islets, respectively, in the mouse body. This study demonstrates a novel and feasible approach to harness the unique features of tumor development for tissue transplantation and regenerative medicine.

Engraftment, neuroglial transdifferentiation and behavioral recovery after complete spinal cord transection in rats.

Background:Proof of the efficacy and safety of a xenogeneic mesenchymal stem cell (MSCs) transplant for spinal cord injury (SCI) may theoretically widen the spectrum of possible grafts for neuroregeneration.Methods:Twenty rats were submitted to complete spinal cord transection. Ovine bone marrow MSCs, retrovirally transfected with red fluorescent protein and not previously induced for neuroglial differentiation, were applied in 10 study rats (MSCG). Fibrin glue was injected in 10 control rats (FGG). All rats were evaluated on a weekly basis and scored using the Basso–Beattie–Bresnahan (BBB) locomotor scale for 10 weeks, when the collected data were statistically analyzed. The spinal cords were then harvested and analyzed with light microscopy, immunohistochemistry, and immunofluorescence.Results:Ovine MSCs culture showed positivity for Nestin. MSCG had a significant and durable recovery of motor functions (P <.001). Red fluorescence was found at the injury sites in MSCG. Positivity for Nestin, tubulin βIII, NG2 glia, neuron-specific enolase, vimentin, and 200 kD neurofilament were also found at the same sites.Conclusions:Xenogeneic ovine bone marrow MSCs proved capable of engrafting into the injured rat spinal cord. Transdifferentiation into a neuroglial phenotype was able to support partial functional recovery.

Systemic recovery and therapeutic effects of transplanted allogenic and xenogenic mesenchymal stromal cells in a rat blunt chest trauma model

BackgroundEffective therapy of Acute Lung Injury (ALI) is still a major scientific and clinical problem. To define novel therapeutic strategies for sequelae of blunt chest trauma (TxT) like ALI/Acute Respiratory Distress Syndrome, we have investigated the immunomodulatory and regenerative effects of a single dose of ex vivo expanded human or rat mesenchymal stromal cells (hMSCs/rMSCs) with or without priming, immediately after the induction of TxT in Wistar rats. MethodsWe analyzed the histological score of lung injury, the cell count of the broncho alveolar lavage fluid (BAL), the change in local and systemic cytokine level and the recovery of the administered cells 24 h and 5 days post trauma. ResultsThe treatment with hMSCs reduced the injury score 24 h after trauma by at least 50% compared with TxT rats without MSCs. In general, TxT rats treated with hMSCs exhibited a lower level of pro-inflammatory cytokines (interleukin [IL]-1B, IL-6) and chemokines (C-X-C motif chemokine ligand 1 [CXCL1], C-C motif chemokine ligand 2 [CCL2]), but a higher tumor necrosis factor alpha induced protein 6 (TNFAIP6) level in the BAL compared with TxT rats after 24 h. Five days after trauma, cytokine levels and the distribution of inflammatory cells were similar to sham rats. In contrast, the treatment with rMSCs did not reveal such therapeutic effects on the injury score and cytokine levels, except for TNFAIP6 level. ConclusionTxT represents a suitable model to study effects of MSCs as an acute treatment strategy after trauma. However, the source of MSCs has to be carefully considered in the design of future studies.

179 Xenogeneic and Allogeneic Mesenchymal Stem Cell Transplantation for Treatment of Tibial Bone Fracture in Mice

Among stem cells, mesenchymal stem cells (MSC) are best suited for therapeutic purposes because of their immunomodulatory properties, ability to be isolated from adult animal at any stage, ease of propagation in the laboratory, and so on. The present study was carried out to isolate and characterise MSC from adipose tissue of mouse (Mus musculus), and to test their application for the treatment of fractured tibia bone in mouse. Cattle and buffalo MSC, already cultured and characterised in our laboratory, were used in the present study as xenogeneic MSC to observe the healing in mouse model. Murine Ad-MSC were isolated from mouse inguinal fat pad by enzymatic digestion method and cultured in growth enriching medium in standard culture conditions. To test the therapeutic potential of MSC, 24 mice were divided into 4 groups: control (C), allogeneic (A), cattle xenogeneic (CX), and buffalo xenogeneic (BX) with 6 mice (having tibial bone mechanical fractured) in each group, and had the corresponding MSC cells injected in the fracture area. The control group was not subjected to any kind of MSC treatment. Post-treatment, healing in all groups was examined for 36 days at different intervals (Days 1, 12, 24, and 36) via digital X-ray imaging. A bone healing score was assigned to each mouse per the protocol provided by RUST (Radiographic Union Scale in Tibial bone) fractures. The results of present study showed that murine Ad-MSC were positive for MSC-specific markers CD44, CD90, CD105, and negative for CD34 and CD45 via RT-PCR and immunocytochemistry. The Ad-MSC were also positive for the alkaline phosphatase staining. Statistical analysis, using Proc GLM (SAS Institute Inc., Cary, NC, USA), revealed that the bone healing was significantly different (P &lt; 0.01) between group C (1.708 ± 0.059) and other groups [group A (2.125 ± 0.061), CX (2.167 ± 0.068), BX (2.250 ± 0.068)], suggesting that healing was greater in groups transplanted with MSC compared with control. However, healing between groups transplanted with MSC (A, CX, and BX) was not significantly different (P &gt; 0.05). In conclusion, we have observed the healing potential of MSC in mouse model via allogeneic and xenogeneic MSC transplantation; the healing potential among the A, CX, and BX MSC groups was similar.

Cytotoxic activity of Holothuria tubulosa (Echinodermata) coelomocytes

The immune system of marine invertebrates, in particular that of holothurians, still requires further study. Our research showed that coelomocyte cells contained in the coelomic fluid of the sea cucumber, Holothuria tubulosa, are able to lyse, in vitro, red blood cells in rabbits and sheep.A plaque-forming assay showed spherule cells to be the effector cells, able to release cytotoxic molecules after xenogenic cell contact. The coelomocyte lysate supernatant, analysed by polyacrylamide gel electrophoresis overlay technique, using rabbit and sheep erythrocytes, showed two different haemolytic protein patterns: one calcium dependent and the other calcium independent. The fractions of each pattern were resolved on a polyacrylamide gel and calcium-dependent and independent coelomocyte lysate patterns were compared.

PreImplantation Factor (PIF*) Regulates Stress-Induced Adrenal Steroidogenesis and Anti-Inflammatory Cytokines: Potential Application for Bioartificial Adrenal Transplant.

The main treatment algorithm for adrenal insufficiency is hormonal replacement, however, inadequate hormone substitution often leads to severe side effects. Adrenal cell transplantation could be a more effective alternative but would require life-long immune suppressive therapy. PreImplantation Factor (PIF) is an endogenous peptide secreted by viable human embryos that leads to maternal tolerance without immunosuppression. PIF could be effective for xenogeneic cell transplantation such as of bovine adrenocortical cells (BAC), which are used for bioartificial adrenal gland development that may more effectively restore complex adrenal functions. We report here that PIF exerts a dual regulatory effect on BAC by targeting mostly hyper-activated cells to specifically reduce adrenocorticotropic hormone (ACTH)-stimulated cortisol secretion. Reverse transcription real time PCR analysis revealed that PIF modulates the expression of two genes in the cortisol synthesis pathway, Steroidogenic Factor 1 (SF1), an activator of steroidogenesis, and the downstream steroidogenic enzyme Cytochrome P450 17A1 (CYP17A1). PIF increased basal expression of SF1 and CYP17A1 regardless of the activation level of the adrenocortical cells. In contrast, following ACTH stimulation, PIF reduced SF1 expression and induced expression of the immune suppressing anti-inflammatory cytokine IL10 only in the hyper-activated cells, suggesting both a protective and immune tolerant function. In conclusion, PIF regulates stress-induced adrenal steroidogenesis and immune tolerance in BAC, supporting a potential clinical application to reduce rejection by the host's immune response following xenotransplantation.

Heart Repair Using Nanogel-Encapsulated Human Cardiac Stem Cells in Mice and Pigs with Myocardial Infarction.

Stem cell transplantation is currently implemented clinically but is limited by low retention and engraftment of transplanted cells and the adverse effects of inflammation and immunoreaction when allogeneic or xenogeneic cells are used. Here, we demonstrate the safety and efficacy of encapsulating human cardiac stem cells (hCSCs) in thermosensitive poly(N-isopropylacrylamine-co-acrylic acid) or P(NIPAM-AA) nanogel in mouse and pig models of myocardial infarction (MI). Unlike xenogeneic hCSCs injected in saline, injection of nanogel-encapsulated hCSCs does not elicit systemic inflammation or local T cell infiltrations in immunocompetent mice. In mice and pigs with acute MI, injection of encapsulated hCSCs preserves cardiac function and reduces scar sizes, whereas injection of hCSCs in saline has an adverse effect on heart healing. In conclusion, thermosensitive nanogels can be used as a stem cell carrier: the porous and convoluted inner structure allows nutrient, oxygen, and secretion diffusion but can prevent the stem cells from being attacked by immune cells.

A PITX3-EGFP Reporter Line Reveals Connectivity of Dopamine and Non-dopamine Neuronal Subtypes in Grafts Generated from Human Embryonic Stem Cells.

SummaryDevelopment of safe and effective stem cell-based therapies for brain repair requires an in-depth understanding of the in vivo properties of neural grafts generated from human stem cells. Replacing dopamine neurons in Parkinson's disease remains one of the most anticipated applications. Here, we have used a human PITX3-EGFP embryonic stem cell line to characterize the connectivity of stem cell-derived midbrain dopamine neurons in the dopamine-depleted host brain with an unprecedented level of specificity. The results show that the major A9 and A10 subclasses of implanted dopamine neurons innervate multiple, developmentally appropriate host targets but also that the majority of graft-derived connectivity is non-dopaminergic. These findings highlight the promise of stem cell-based procedures for anatomically correct reconstruction of specific neuronal pathways but also emphasize the scope for further refinement in order to limit the inclusion of uncharacterized and potentially unwanted cell types.

Autonomous xenogenic cell fusion of murine and chick skeletal muscle myoblasts.

Cell-cell fusion has been a great technology to generate valuable hybrid cells and organisms such as hybridomas. In this study, skeletal muscle myoblasts were utilized to establish a novel method for autonomous xenogenic cell fusion. Myoblasts are mononuclear myogenic precursor cells and fuse mutually to form multinuclear myotubes. We generated murine myoblasts (mMBs) expressing green fluorescent protein (GFP) termed mMB-GFP, and the chick myoblasts (chMBs) expressing Discosoma red fluorescent protein (DsRed) termed chMB-DsRed. mMB-GFP and chMB-DsRed were cocultured and induced to differentiate. After 24h, the multinuclear myotubes expressing both GFP and DsRed were observed, indicating that mMBs and chMBs interspecifically fuse. These GFP+ /DsRed+ hybrid myotubes were able to survive and grew to hyper-multinucleated mature form. We also found that undifferentiated mMB-GFP efficiently fuse to the chMB-DsRed-derived myotubes. This is the first evidence for the autonomous xenogenic fusion of mammalian and avian cells. Myoblast-based fusogenic technique will open up an alternative direction to create novel hybrid products.

Human regulatory macrophages are potent in suppression of the xenoimmune response via indoleamine-2,3-dioxygenase-involved mechanism(s).

For xenotransplantation to truly succeed, we must develop immunomodulatory strategies to suppress the xenoimmune response but by minimizing immunosuppression over the long term. Regulatory macrophages (Mreg) have been shown to suppress polyclonal T-cell proliferation in vitro and prolong allograft survival in vivo. However, the question of whether they are capable of suppressing xenoimmune responses remains unknown. This study assessed the potential of human Mreg to be used as an effective immunomodulatory method in xenotransplantation. CD14+ monocytes selected from human peripheral blood mononuclear cells (PBMC) were cultured with macrophage colony-stimulating factor (M-CSF) for 7days with IFN-γ added at day 6 for Mreg induction. Mreg phenotyping was performed by flow cytometric analysis, and the in vitro suppressive function was assessed by mixed lymphocyte reaction (MLR) using irradiated pig PBMC as the xenogeneic stimulator cells, human PBMC as responder cells, and autologous Mreg as suppressor cells. To assess mRNA expression of Mreg functional molecules indoleamine-2,3-dioxygenase (IDO), IL-10, inducible nitric oxide synthase (iNOS) and TGF-β were measured by real-time PCR. Supernatants were collected from the MLR cultures for IDO activity assay by high-performance liquid chromatography (HPLC). The effects of the IDO inhibitor 1-D/L-methyl-tryptophan (1-MT), iNOS inhibitor NG -monomethyl-l-arginine (L-NMMA), and anti-IFN-γ or anti-TGF-β monoclonal antibody (mAb) treatment on Mreg suppressive capacity were tested from the supernatants of the MLR assays. We demonstrated that induced Mreg with a phenotype of CD14low CD16-/low CD80low CD83-/low CD86+/hi HLA-DR+/hi were capable of suppressing proliferating human PBMC, CD4+, and CD8+ T cells, even at a higher responder:Mreg ratio of 32:1 in a pig-human xenogeneic MLR. The strong suppressive potency of Mreg was further correlated with their upregulated IDO expression and activity. The IDO upregulation of Mreg was associated with an increased production of IFN-γ, an IDO stimulator, by xenoreactive responder cells in the xenogeneic MLR. While no effect on Mreg suppressive potency was detected by addition of the iNOS inhibitor L-NMMA or anti-TGF-β mAb into the MLR assays, inhibition of IDO activity by neutralizing IFN-γ or by IDO inhibitor 1-MT substantially impaired the capacity of Mreg to suppress the xenogeneic response, indicating the importance of upregulated IDO activity in Mreg-mediated suppression of the xenogeneic response in vitro. This study demonstrates that human Mreg are capable of suppressing the xenoimmune response in vitro via IDO-involved mechanism(s), suggesting their potential role as an effective immunomodulatory tool in xenotransplantation.

P2570Intravenous administration of xenogenic adipose-derived mesenchymal stem cells (ADMSC) and ADMSC-derived exosomes markedly reduced brain infarct volume and preserved neurological function in rat after

P2570Intravenous administration of xenogenic adipose-derived mesenchymal stem cells (ADMSC) and ADMSC-derived exosomes markedly reduced brain infarct volume and preserved neurological function in rat after

Regeneration of hyaline cartilage promoted by xenogeneic mesenchymal stromal cells embedded within elastin-like recombinamer-based bioactive hydrogels.

Over the last decades, novel therapeutic tools for osteochondral regeneration have arisen from the combination of mesenchymal stromal cells (MSCs) and highly specialized smart biomaterials, such as hydrogel-forming elastin-like recombinamers (ELRs), which could serve as cell-carriers. Herein, we evaluate the delivery of xenogeneic human MSCs (hMSCs) within an injectable ELR-based hydrogel carrier for osteochondral regeneration in rabbits. First, a critical-size osteochondral defect was created in the femora of the animals and subsequently filled with the ELR-based hydrogel alone or with embedded hMSCs. Regeneration outcomes were evaluated after three months by gross assessment, magnetic resonance imaging and computed tomography, showing complete filling of the defect and the de novo formation of hyaline-like cartilage and subchondral bone in the hMSC-treated knees. Furthermore, histological sectioning and staining of every sample confirmed regeneration of the full cartilage thickness and early subchondral bone repair, which was more similar to the native cartilage in the case of the cell-loaded ELR-based hydrogel. Overall histological differences between the two groups were assessed semi-quantitatively using the Wakitani scale and found to be statistically significant (p < 0.05). Immunofluorescence against a human mitochondrial antibody three months post-implantation showed that the hMSCs were integrated into the de novo formed tissue, thus suggesting their ability to overcome the interspecies barrier. Hence, we conclude that the use of xenogeneic MSCs embedded in an ELR-based hydrogel leads to the successful regeneration of hyaline cartilage in osteochondral lesions.

Mouse↔rat aggregation chimaeras can develop to adulthood

In order to examine interactions between cells originating from different species during embryonic development we constructed interspecific mouse↔rat chimaeras by aggregation of 8-cell embryos. Embryos of both species expressed different fluorescent markers (eGFP and DsRed), which enabled us to follow the fate of both components from the moment of aggregation until adulthood. We revealed that in majority of embryos the blastocyst cavity appeared inside the group of rat cells, while the mouse component was allocated to the deeper layer of the inner cell mass and to the polar trophectoderm. However, due to rearrangement of all cells and selective elimination of rat cells, shortly before implantation all primary lineages became chimaeric. Moreover, despite the fact that rat cells were always present in the mural trophectoderm, majority of mouse↔rat chimaeric blastocysts implanted in mouse uterus, and out of those 46% developed into foetuses and pups, half of which were chimaeric. In contrast to mural trophectoderm, polar trophectoderm derivatives, i.e. the placentae of all chimaeras were exclusively of mouse origin. This strongly suggests that the successful postimplantation development of chimaeras is enabled by gradual elimination of xenogeneic cells from the nascent placenta. The size of chimaeric newborns was within the limits of control mouse neonates. The rat component located preferentially in the anterior part of the body, where it contributed mainly to the neural tube. Our observations indicate that although chimaeric animals were able to reach adulthood, high contribution of rat cells tended to diminish their viability.

Quantitative variations of CD4&lt;sup&gt;+&lt;/sup&gt;CD25&lt;sup&gt;+&lt;/sup&gt; cells in Peking duckwhite leghorn chimeras based on bone marrow mesenchymal stem cells

Purpose: To develop a chimera via microinjection of poultry xenogeneic bone marrow mesenchymal stem cells (BMMSCs), and to assess its immune tolerance based on variations in proportion of CD4 + CD25 + cells in CD4 + cells (specific CD4 + CD25 + cells). Methods: BMMSCs were flush out from femurs and tibias of Peking ducks with phosphate-buffered saline and cultured. Their morphology was determined with a microscope. Several surface markers (i.e., CD44, CD45, CD71, CD73 and CD34) were used to identify the cells. Results: The results indicate successful chimera development. CD4 + CD25 + cells derived from the thymus of chimeras were migrated to the spleen and cecal tonsils. This migration was more obvious in chimeras than in the control group, suggesting a more robust immune system in the chimeras. The migration tendency gradually decreased with time. There were significant increases in specific CD4 + CD25 + cells, TGF-β and IL-10 in cecal tonsils throughout the experimental period (30 days). However, in thymus and spleen, variations in specific CD4 + CD25 + cells were observed only on the 1st day post-hatching. Conclusion: The results suggest a relatively pure BMMSC population without contaminating hematopoietic stem cells. Differentiation of the BMMSCs into osteoblasts and adipocytes was inducible, indicating typical MSC character. Keywords: Bone marrow mesenchymal stem cells, Immune tolerance, Chimera, Specific CD4 + CD25 + cells, Cell migration

Evaluating the Therapeutic Potential of Transplantation of Neural Precursor Cells for Treating the Autoimmune Disease Multiple Sclerosis

Abstract Multiple Sclerosis is a chronic, autoimmune disease for which there is currently no cure. Previous studies suggest transplantation of neural precursor cells (NPCs) is a promising therapeutic strategy to treat neurological disorders. Using two mouse models of MS, experimental autoimmune encephalomyelitis (EAE) and murine hepatitis virus (MHV), we have observed remyelination and decreased neuroinflammation when mice received an intra-spinal transplant of syngeneic mouse GFP-NPCs. This recovery was due to replacement of damaged cells and had little effect upon immune responses. In contrast, transplantation of xenogeneic human embryonic stem cell (hESC) derived NPCs (hNPCs) or induced pluripotent stem cell (iPSC) derived NPCs (hiNPCs) modulates the host immune response. Mice receiving intra-spinal transplants of human NPCs displayed less demyelination, decreased neuroinflammation, and an increase in T regulatory cells (Tregs). Recovery was not a result of cell replacement by hNPCs because transplanted cells underwent rapid xenograft rejection. Importantly, ablation of Tregs abrogated clinical and histopathological improvement mediated by hNPC transplantation. Furthermore, hNPCs promote the induction of naïve T cells into Tregs in co-cultures in vitro. However, the mechanisms and factors that propagate Treg induction and function resulting in subsequent endogenous remyelination remain undiscovered. We hypothesize rejection of NPCs plays a role in generation of Tregs in vitro and in vivo. Future experiments will focus on elucidating the factors from hNPCs that are responsible for Treg differentiation and evaluate the ability of syngeneic, allogeneic, and xenogeneic NPCs to generate Tregs.

Anti-A Antibody Response is Dependent on CD4 T Cells and Co-Engagement With Foreign Protein

: Introduction: ABO-incompatible heart transplantation (ABOi HTx) is safe during infancy and allows increased donor access. B cell tolerance develops to donor A/B-antigen(s) after ABOi HTx by mechanisms not well defined. We developed A-transgenic (A-Tg) mice constitutively expressing human A-antigen on vascular endothelium and erythrocytes (RBC) to study B cell immunity and tolerance. Here we studied A-incompatibility in the context of syngeneic, allogeneic and xenogeneic stimulation. Methods:Part I: Adult wild-type (WT) C57BL/6 (B6; H-2b), BALB/c (BALB; H-2d), or C3H/He mice (C3H; H-2k) received i.p. injection weekly x3 of B6 or BALB A-Tg RBC membrane (100 μl of 10% vol/vol); or human RBC membranes (100 μl of 10% vol/vol) from blood group A or O; or A-incompatible heart allografts (Table). Serum anti-A antibody was measured by hemagglutination and ELISA (IgG and IgM); graft survival was assessed by palpation. Part II: a) to assess requirement for ‘linkage’ of the non-self carbohydrate A-antigen with foreign protein to stimulate anti-A, human O-RBC were co-injected in B6 WT mice with syngeneic A-Tg cells; b) to assess T cell dependence of anti-A response, CD4+ T cells were depleted (mAb GK1.5) from B6 WT mice before human A RBC injection. Results:Part I: Exposure to incompatible A-antigen in the context of allogeneic stimulation (MHC-mismatched A-Tg blood or heart graft) or xenogeneic stimulation (human A-RBC) induced abundant anti-A production (Table), whereas A-Tg syngeneic (MHC-matched) cells did not. Part II: a) a mixture of syngeneic A-Tg and xenogeneic human O-RBC did not induce anti-A; b) after CD4+ T cell depletion, xenogeneic cells failed to elicit anti-A. Conclusion: Exposure to non-self A-antigen in syngeneic cells is insufficient to induce anti-A production; stimulation of antibody depends not only on exposure to the foreign carbohydrate but co-engagement with allogeneic or xenogeneic protein, and requires CD4 T cell help. These results are consistent with our previous data showing a requirement for chemical/physical linkage of non-self A-antigen and foreign protein. This research was supported by the Heart and Stroke Foundation of Canada, Canadian Institutes of Health Research, Canadian Glycomics Network, and Stollery Children's Hospital Foundation through the Women and Children's Health Research Institute.Table: No title available.

Induction of experimental autoimmune orchitis by immunization with xenogenic testicular germ cells in mice

We previously showed that immunization of mice with syngeneic or allogeneic testicular germ cells (TGC) alone induces autoimmune inflammation in the testes without using any adjuvant. In the present study, we examined testicular autoimmune response against xenogenic TGC antigens in mice. The mice were immunized with murine, rat or guinea pig TGC and then the histopathology, delayed type hypersensitivity (DTH) response and humoral autoimmunity were investigated. The results showed that immunization with not only murine but also rat TGC caused experimental autoimmune orchitis (EAO) with hypospermatogenesis in mice, while that with guinea pig TGC could not. The DTH response to murine TGC was significantly elevated in mice that had been immunized with murine or rat but not guinea pig TGC. Serum autoantibody to murine TGC was immunohistochemically detected in the mice immunized with either murine, rat or guinea pig TGC, however, the level of autoantibody detected by ELISA revealed significant elevation when mice were immunized with murine and rat TGC. With the immunoblotting after electrophoresis, the murine TGC proteins at molecular masses around 55kDa and 70kDa can be detected when incubated with sera from m-TGC and r-TGC groups. These results represent the cross-reactivity among TGC of the mouse, the rat and the guinea pig at the levels of humoral immunity and also demonstrate that the rat TGC could elicit significant DTH response to murine TGC with the resultant EAO. This is the first to succeed in EAO induction by the use of xenogenic TGC.

Xenogeneic human umbilical cord-derived mesenchymal stem cells reduce mortality in rats with acute respiratory distress syndrome complicated by sepsis.

This study tested the hypothesis that xenogeneic human umbilical cord-derived mesenchymal stem cell (HUCDMSC) therapy would improve survival rates in rats with acute respiratory distress-syndrome (ARDS, induction by 48 h inhalation of 100% oxygen) and sepsis-syndrome (SS, induction by cecal-ligation and puncture) (ARDS-SS). Adult-male Sprague-Dawley rats were categorized into group 1 (sham-controls), group 2 (ARDS-SS), group 3 [ARDS-SS+HUCDMSC (1.2 ×106 cells administered 1 h after SS-induction)], and group 4 [ARDS-SS+HUCDMSC (1.2 ×106 cells administered 24 h after SS-induction)]. The mortality rate was higher in groups 2 and 4 than in groups 1 and 3 (all p<0.0001). The blood pressure after 28 h was lower in groups 2, 3 and 4 (p<0.0001) than in group 1. Albumin levels and percentages of inflammatory cells in broncho-alveolar lavage fluid, and the percentages of inflammatory and immune cells in circulation, were lowest in group 1, highest in group 2, and higher in group 3 than group 4 (all p<0.0001). The percentages of inflammatory cells in ascites and kidney parenchyma showed identical patterns, as did kidney injury scores (all p<0.0001). EarlyHUCDMSC therapy reduced rodent mortality after induced ARDS-SS.

Concise Review: Innate and Adaptive Immune Recognition of Allogeneic and Xenogeneic Cell Transplants in the Central Nervous System.

Over the last 30 years, numerous allogeneic and xenogeneic cell grafts have been transplanted into the central nervous system (CNS) of mice and men in an attempt to cure neurological diseases. In the early studies, human or porcine embryonic neural cells were grafted in the striatum of animals or patients in an attempt to replace lost neurons. Although the immune‐privileged status of the brain as a recipient organ was widely accepted, it rapidly became evident that CNS‐grafted allogeneic and xenogeneic cells could be recognized and rejected by the immune system, resulting in poor neural graft survival and limited functional recovery. Since then, the CNS transplantation field has witnessed a sharp rise in the number of studies in which allogeneic and xenogeneic neural or mesenchymal stem cells (NSCs or MSCs, respectively) are transplanted, predominantly aiming at providing trophic stimulation and promoting endogenous repair of the brain. Interestingly, in many recent NSC and MSC‐based publications functional improvement was used as the principal measure to evaluate the success of cell transplantation, while the fate of transplanted cells remained largely unreported. In this review, we first attempt to understand why primary neural cell isolates were largely substituted for NSCs and MSCs in cell grafting studies. Next, we review the current knowledge on the immune mechanisms involved in the recognition and rejection of allogeneic and xenogeneic cellular grafts in the CNS. Finally, we propose strategies to reduce graft immunogenicity and to improve graft survival in order to design improved cell‐based CNS therapies. Stem Cells Translational Medicine 2017;6:1434–1441

Establishment of intraperitoneal germ cell transplantation for critically endangered Chinese sturgeon Acipenser sinensis

Recent progress in germ cell transplantation techniques in fish has paved the way for the conservation of endangered species. Here, we developed an intraperitoneal germ cell transplantation procedure using Chinese and Dabry's sturgeon as donor and recipient species, respectively. Histological analysis revealed that primordial germ cells migrated on the peritoneal wall at 16 days post-hatch (dph) in Dabry's sturgeon. The genital ridges of Dabry's sturgeon (recipient) first formed at 28 dph, suggesting that for successful colonization of donor germ cells in the recipient gonads, the transplantation should be performed earlier than this age. Sexual dimorphism of gonadal structure was first observed at 78 dph. Gonadal germ cell proliferation was not seen in either sex during this period. Immunohistochemistry using the anti-Vasa antibody found that donor testes from 2-year-old Dabry's sturgeon mainly consisted of single- or paired-type A spermatogonia, while donor ovaries from 11.5-year-old Chinese sturgeon had perinucleolus stage oocytes and clusters of oogonia. Donor cells isolated from Dabry's sturgeon testes or Chinese sturgeon ovary labeled with PKH26 fluorescent dye were transplanted into the peritoneal cavity of the 7- or 8-dph Dabry's sturgeon larvae. More than 90% and 70% of transplanted larvae survived after 2 days post-transplantation (dpt) and 51 dpt, respectively. At 51 dpt, PKH26-labeled cells exhibiting germ cell-specific nuclear morphology and diameter were observed in excised recipient gonads by fluorescent and confocal microscopy. The colonization rate of allogeneic testicular germ cell transplantation (Group 1) was 70%, while that of two batches of xenogeneic ovarian germ cell transplantation (Group 2 and Group 3) were 6.7% and 40%, respectively. The ratio of colonized germ cells to endogenous germ cells was 11.96%, 5.35% and 3.56% for Group 1, Group 2 and Group 3, respectively. Thus, we established a germ cell transplantation technique for the critically endangered Chinese sturgeon using the most closely related species as a recipient and demonstrated the successful preparation of transplantable female germ cells from aged adult Chinese sturgeon.