Human umbilical cord blood cells restore vascular integrity in injured rat brain and modulate inflammation in vitro

Umbilical cord blood derived cell expansion: a potential neuroprotective therapy

Umbilical cord blood (UCB) is a rich source of beneficial stem and progenitor cells with known angiogenic, neuroregenerative and immune-modulatory properties. Preclinical studies have highlighted the benefit of UCB for a broad range of conditions including haematological conditions, metabolic disorders and neurological conditions, however clinical translation of UCB therapies is lacking. One barrier for clinical translation is inadequate cell numbers in some samples meaning that often a therapeutic dose cannot be achieved. This is particularly important when treating adults or when administering repeat doses of cells. To overcome this, UCB cell expansion is being explored to increase cell numbers. The current focus of UCB cell expansion is CD34+ haematopoietic stem cells (HSCs) for which the main application is treatment of haematological conditions. Currently there are 36 registered clinical trials that are examining the efficacy of expanded UCB cells with 31 of these being for haematological malignancies. Early data from these trials suggest that expanded UCB cells are a safe and feasible treatment option and show greater engraftment potential than unexpanded UCB. Outside of the haematology research space, expanded UCB has been trialled as a therapy in only two preclinical studies, one for spinal cord injury and one for hind limb ischemia. Proteomic analysis of expanded UCB cells in these studies showed that the cells were neuroprotective, anti-inflammatory and angiogenic. These findings are also supported by in vitro studies where expanded UCB CD34+ cells showed increased gene expression of neurotrophic and angiogenic factors compared to unexpanded CD34+ cells. Preclinical evidence demonstrates that unexpanded CD34+ cells are a promising therapy for neurological conditions where they have been shown to improve multiple indices of injury in rodent models of stroke, Parkinson's disease and neonatal hypoxic ischemic brain injury. This review will highlight the current application of expanded UCB derived HSCs in transplant medicine, and also explore the potential use of expanded HSCs as a therapy for neurological conditions. It is proposed that expanded UCB derived CD34+ cells are an appropriate cellular therapy for a range of neurological conditions in children and adults.

Advancing cell therapy for neurodegenerative diseases

Cell-based therapies are being developed for various neurodegenerative diseases that affect the central nervous system (CNS). Concomitantly, the roles of individual cell types in neurodegenerative pathology are being uncovered by genetic and single-cell studies. With a greater understanding of cellular contributions to health and disease and with the arrival of promising approaches to modulate them, effective therapeutic cell products are now emerging. This review examines how the ability to generate diverse CNS cell types from stem cells, along with a deeper understanding of cell-type-specific functions and pathology, is advancing preclinical development of cell products for the treatment of neurodegenerative diseases.

Determining Sex-Based Differences in Inflammatory Response in an Experimental Traumatic Brain Injury Model

Introduction

Traumatic brain injury is a leading cause of injury-related death and morbidity. Multiple clinical and pre-clinical studies have reported various results regarding sex-based differences in TBI. Our accepted rodent model of traumatic brain injury was used to identify sex-based differences in the pathological features of TBI.

Methods

Male and female Sprague-Dawley rats were subjected to either controlled-cortical impact (CCI) or sham injury; brain tissue was harvested at different time intervals depending on the specific study. Blood-brain barrier (BBB) analysis was performed using infrared imaging to measure fluorescence dye extravasation. Microglia and splenocytes were characterized with traditional flow cytometry; microglia markers such as CD45, P2Y12, CD32, and CD163 were analyzed with t-distributed stochastic neighbor embedding (t-SNE). Flow cytometry was used to study tissue cytokine levels, and supplemented with ELISAs of TNF-⍺, IL-17, and IL-1β of the ipsilateral hemisphere tissue.

Results

CCI groups of both sexes recorded a higher BBB permeability at 72 hours post-injury than their respective sham groups. There was significant difference in the integrated density value of BBB permeability between the male CCI group and the female CCI group (female CCI mean = 3.08 x 108 ± 2.83 x 107, male CCI mean = 2.20 x 108 ± 4.05 x 106, p = 0.0210), but otherwise no differences were observed. Traditional flow cytometry did not distinguish any sex-based difference in regards to splenocyte cell population after CCI. t-SNE did not reveal any significant difference between the male and female injury groups in the activation of microglia. Cytokine analysis after injury by flow cytometry and ELISA was limited in differences at the time point of 6 hours post-injury.

Conclusion

In our rodent model of traumatic brain injury, sex-based differences in pathology and neuroinflammation at specified time points are limited, and only noted in one specific analysis of BBB permeability.

The Role of Cord Blood in the Regulation of the Cellular and Humoral Link of Immunity in Experimental Atopic Dermatitis

Background. Atopic dermatitis (AD) as one of the most common diseases of autoimmune genesis in the structure of dermatological practice, is characterized by itching, dryness, thickening of the skin, characteristic rashes. The drugs of choice in the treatment of AD are steroidal anti-inflammatory drugs. However, the development of unwanted side effects is a serious problem attributed to using hormone therapy. The search for effective methods of treating AD is an urgent task of medicine and in particular dermatology. At the same time, there is an obvious need for the participation in the solution of this problem also of specialists-immunologists working in the field of application of cell therapy drugs, acting on various pathogenetic links of the disease. The development of new or optimization of existing methods of treating AD is the urgent task facing them. Objective. Evaluation of the immunocorrective effect of lyophilized (lHCBL) and cryopreserved human cord blood leucoconcetrate (cHCBL) on a AD model. Methods. The experiments were carried out on 6-month-old Wistar rats. Upon induction of AD, the inflammation focus was formed on the rat's back (9–10 cm2) by daily rubbing in a 5% alcohol-acetone solution of dinitrochlorobenzene (DNCB) for 21 days. cHCBL and lHCBL were injected intraperitoneally, 0.5 ml at a dose of 5´106 cells in one day after the final DNCB treatment. The adhesive and phagocytic activity of the cells of the peritoneal cavity, the level of circulating immune complexes, the population and subpopulation of lymphocytes (CD3+, CD4+, CD8+, CD16+, CD4+CD25+), the immunoregulatory index of lymphocytes, the concentration of immunoglobulins in the blood serum were determined. Results. For AD induced by DNCB, systemic changes in the immune status are characteristic, which is expressed by changes in the parameters of cellular and humoral immunity. The most fundamental changes in cell subpopulations in spleen of rats with AD were revealed: a decrease in the number of total T-lymphocytes and their two main subpopulations (CD4+ and CD8+ cells). Against this background, changes were noted in the monocytic-phagocytic and humoral systems of immunity. The paper shows the effectiveness of the use of cHCBL and lHCBL in the correction of pathological manifestations of experimental AD. On the background of treatment, the features of the immunocorrective effect of each of the drugs were noted. Thus, when assessing intergroup values, a more pronounced increase in T-reg was revealed in rats of the 5th group – 3.9 [3.8; 4.0] versus 3.2 [3.0; 3.3] in the 4th group (P < 0.01); IgA level – 1.6 [1.5; 1.7] versus 1.3 [1.2; 1.4] (P < 0.01). Conclusions. Thus, lHCBL exhibits immunocorrective activity in the treatment of experimental AD, surpassing in some parameters the activity of сHCBL, which is promising for its use in clinical practice.

Combination therapy with Treg and mesenchymal stromal cells enhances potency and attenuation of inflammation after traumatic brain injury compared to monotherapy

The inflammatory response after traumatic brain injury (TBI) can lead to significant secondary brain injury and chronic inflammation within the central nervous system. Cell therapies, including mesenchymal stromal cells (MSC), have led to improvements in animal models of TBI and are under investigation in human trials. One potential mechanism for the therapeutic potential of MSC is their ability to augment the endogenous response of immune suppressive regulatory T cells (Treg). We have recently shown that infusion of human cord blood Treg decreased chronic microgliosis after TBI and altered the systemic immune response in a rodent model. These cells likely use both overlapping and distinct mechanisms to modulate the immune system; therefore, combining Treg and MSC as a combination therapy may confer therapeutic benefit over either monotherapy. However, investigation of Treg + MSC combination therapy in TBI is lacking. In this study, we compared the ability MSC + Treg combination therapy, as well as MSC and Treg monotherapies, to inhibit the neuroinflammatory response to TBI in vivo and in vitro. Treg + MSC combination therapy demonstrated increased potency to reduce the neuro- and peripheral inflammatory response compared to monotherapy; furthermore, the timing of infusion proved to be a significant variable in the efficacy of both MSC monotherapy and Treg + MSC combination therapy in vivo and in vitro.

Umbilical cord blood cells for the treatment of preterm white matter injury: Potential effects and treatment options

Preterm birth is a global public health problem. A large number of preterm infants survive with preterm white matter injury (PWMI), which leads to neurological deficits, and has multifaceted etiology, clinical course, monitoring, and outcomes. The principal upstream insults leading to PWMI initiation are hypoxia-ischemia and infection and/or inflammation and the key target cells are late oligodendrocyte precursor cells. Current PWMI treatments are mainly supportive, and thus have little effect in terms of protecting the immature brain or repairing injury to improve long-term outcomes. Umbilical cord blood (UCB) cells comprise abundant immunomodulatory and stem cells, which have the potential to reduce brain injury, mainly due to anti-inflammatory and immunomodulatory mechanisms, and also through their release of neurotrophic or growth factors to promote endogenous neurogenesis. In this review, we briefly summarize PWMI pathogenesis and pathophysiology, and the specific properties of different cell types in UCB. We further explore the potential mechanism by which UCB can be used to treat PWMI, and discuss the advantages of and potential issues related to UCB cell therapy. Finally, we suggest potential future studies of UCB cell therapy in preterm infants.

Human cord blood-derived regulatory T-cell therapy modulates the central and peripheral immune response after traumatic brain injury

Traumatic brain injury (TBI) causes a profound inflammatory response within the central nervous system and peripheral immune system, which contributes to secondary brain injury and further morbidity and mortality. Preclinical investigations have demonstrated that treatments that downregulate microglia activation and polarize them toward a reparative/anti-inflammatory phenotype have improved outcomes in preclinical models. However, no therapy to date has translated into proven benefits in human patients. Regulatory T cells (Treg) have been shown to downregulate pathologic immune responses of the innate and adaptive immune system across a variety of pathologies. Furthermore, cellular therapy has been shown to augment host Treg responses in preclinical models; yet, studies investigating the use of Treg as a therapeutic for TBI are lacking. In a rodent TBI model, we demonstrate that human umbilical cord blood Treg modulate the central and peripheral immune response after injury in vitro and in vivo.

The Development of Stem Cell-Based Treatment for Acute Ischemic Cerebral Injury

Acute ischemic brain injury is a serious disease that severely endangers the life safety of patients. Such disease is hard to predict and highly lethal with very limited effective treatments currently. Although currently, there exist treatments like drug therapy, hyperbaric oxygen therapy, rehabilitation therapy and other treatments in clinical practice, these are not significantly effective for patients when the situation is severe. Thus scientists must explore more effective treatments. Stem cells are undifferentiated cells with a strong potential of self-renewal and differentiate into various types of tissues and organs. Their emergence has brought new hopes for overcoming difficult diseases, further improving medical technology and promoting the development of modern medicine. Some combining therapies and genetically modified stem cell therapy have also been proven to produce obvious neuroprotective function for acute ischemic brain injury. This review is an introduction to the current research findings and discusses the definition, origin and classification of stem cells, as well as the future prospects of the stem cell-based treatment for acute ischemic cerebral injury.