Mild therapeutic hypothermia upregulates the O-GlcNAcylation level of COX10 to alleviate mitochondrial damage induced by myocardial ischemia-reperfusion injury.

OBJECTIVE: Mild therapeutic hypothermia (MTH) is an important method for perioperative prevention and treatment of myocardial ischemia-reperfusion injury (MIRI). Modifying mitochondrial proteins after protein translation to regulate mitochondrial function is one of the mechanisms for improving myocardial ischemia-reperfusion injury. This study investigated the relationship between shallow hypothermia treatment improving myocardial ischemia-reperfusion injury and the O-GlcNAcylation level of COX10. METHODS: We used in vivo Langendorff model and in vitro hypoxia/reoxygenation (H/R) cell model to investigate the effects of MTH on myocardial ischemia-reperfusion injury. Histological changes, myocardial enzymes, oxidative stress, and mitochondrial structure/function were assessed. Mechanistic studies involved various molecular biology methods such as ELISA, immunoprecipitation (IP), WB, and immunofluorescence. RESULTS: Our research results indicate that MTH upregulates the O-GlcNACylation level of COX10, improves mitochondrial function, and inhibits the expression of ROS to improve myocardial ischemia-reperfusion injury. In vivo, MTH effectively alleviates ischemia-reperfusion induced cardiac dysfunction, myocardial injury, mitochondrial damage, and redox imbalance. In vitro, the OGT inhibitor ALX inhibits the OGT mediated O-GlcNA acylation signaling pathway, downregulates the O-Glc acylation level of COX10, promotes ROS release, and counteracts the protective effect of MTH. On the contrary, the OGA inhibitor ThG showed opposite effects to ALX, further confirming that MTH activated the OGT mediated O-GlcNAcylation signaling pathway to exert cardioprotective effects. CONCLUSIONS: In summary, MTH activates OGT mediated O-glycosylation modified COX10 to regulate mitochondrial function and improve myocardial ischemia-reperfusion injury, which provides important theoretical basis for the clinical application of MTH.

SARS-CoV-2-specific T cells are rapidly expanded for therapeutic use and target conserved regions of the membrane protein.

T-cell responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been described in recovered patients, and may be important for immunity following infection and vaccination as well as for the development of an adoptive immunotherapy for the treatment of immunocompromised individuals. In this report, we demonstrate that SARS-CoV-2-specific T cells can be expanded from convalescent donors and recognize immunodominant viral epitopes in conserved regions of membrane, spike, and nucleocapsid. Following in vitro expansion using a good manufacturing practice-compliant methodology (designed to allow the rapid translation of this novel SARS-CoV-2 T-cell therapy to the clinic), membrane, spike, and nucleocapsid peptides elicited interferon-γ production, in 27 (59%), 12 (26%), and 10 (22%) convalescent donors (respectively), as well as in 2 of 15 unexposed controls. We identified multiple polyfunctional CD4-restricted T-cell epitopes within a highly conserved region of membrane protein, which induced polyfunctional T-cell responses, which may be critical for the development of effective vaccine and T-cell therapies. Hence, our study shows that SARS-CoV-2 directed T-cell immunotherapy targeting structural proteins, most importantly membrane protein, should be feasible for the prevention or early treatment of SARS-CoV-2 infection in immunocompromised patients with blood disorders or after bone marrow transplantation to achieve antiviral control while mitigating uncontrolled inflammation.

Comparable transforming growth factor beta-mediated immune suppression in ex vivo-expanded natural killer cells from cord blood and peripheral blood: implications for adoptive immunotherapy.

T cell-based therapies like genetically modified immune cells expressing chimeric antigen receptors have shown robust anti-cancer activity in vivo, especially in patients with blood cancers. However, extending this approach to an "off-the-shelf" setting can be challenging, as allogeneic T cells carry a significant risk of graft-versus-host disease (GVHD). By contrast, allogeneic natural killer (NK) cells recognize malignant cells without the need for prior antigen exposure and have been used safely in multiple cancer settings without the risk of GVHD. However, similar to T cells, NK cell function is negatively impacted by tumor-induced transforming growth factor beta (TGF-ß) secretion, which is a ubiquitous and potent immunosuppressive mechanism employed by most malignancies. Allogeneic NK cells for adoptive immunotherapy can be sourced from peripheral blood (PB) or cord blood (CB), and the authors' group and others have previously shown that ex vivo expansion and gene engineering can overcome CB-derived NK cells' functional immaturity and poor cytolytic activity, including in the presence of exogenous TGF-ß.  However, a direct comparison of the effects of TGF-ß-mediated immune suppression on ex vivo-expanded CB- versus PB-derived NK cell therapy products has not previously been performed. Here the authors show that PB- and CB-derived NK cells have distinctive gene signatures that can be overcome by ex vivo expansion. Additionally, exposure to exogenous TGF-ß results in an upregulation of inhibitory receptors on NK cells, a novel immunosuppressive mechanism not previously described. Finally, the authors provide functional and genetic evidence that both PB- and CB-derived NK cells are equivalently susceptible to TGF-ß-mediated immune suppression. The authors believe these results provide important mechanistic insights to consider when using ex vivo-expanded, TGF-ß-resistant PB- or CB-derived NK cells as novel immunotherapy agents for cancer.

Spike-directed vaccination elicits robust spike-specific T-cell response, including to mutant strains.

Although most studies describing coronavirus disease 2019 vaccine responses have focused on antibodies, there is increasing evidence that T cells play a critical role. Here the authors evaluated T-cell responses in seronegative donors before and after vaccination to define responses to the severe acute respiratory syndrome coronavirus 2 reference strain as well as to mutations in the variant strains Alpha/B.1.1.7 and Beta/B.1.351. The authors observed enhanced T-cell responses to reference and variant spike strains post-vaccination.

Ligustilide enhances hippocampal neural stem cells activation to restore cognitive function in the context of postoperative cognitive dysfunction.

Ligustilide exerts potential neuroprotective effects against various cerebral ischaemic insults and neurodegenerative disorders. However, the function and mechanisms of LIG-mediated hippocampal neural stem cells (H-NSCs) activation as well as cognitive recovery in the context of post-operative cognitive dysfunction (POCD) remain elusive and need to be explored. Mice were subjected to transient global cerebral ischaemia and reperfusion (tGCI/R) injury and treated with LIG (80 mg/kg) or vehicle for 1 month. Morris water maze test and western blot were employed to assess cognitive function. Nissl staining and immunofluorescence (IF) staining were used to detect H-NSCs proliferation and neurogenesis in hippocampus. Subsequently, primary H-NSCs were treated with LIG, and the level of H-NSCs proliferation and neuronal-differentiation was examined by IF staining for Edu and ß-Tubulin III. The protein levels of ERK1/2, ß-catenin, NICD, TLR4, Akt and FoxO1 were examined using western blotting. Finally, pretreatment with the ERK agonist SCH772984 was performed to observe the change in ERK expression. LIG treatment promoted H-NSCs proliferation and neurogenesis, increased the number of neurons in the hippocampal subfields, and ultimately reversed cognitive impairment in tGCI/R injury. Furthermore, LIG also promoted primary H-NSCs proliferation and neuronal-differentiation, as well as ERK1/2 phosphorylation. Pretreatment with SCH772984 effectively reversed the ability of LIG to induce ERK1/2 phosphorylation and promote H-NSCs proliferation and neuronal-differentiation. LIG can promote cognitive recovery after tGCI/R injury by activating ERK1/2 in H-NSCs to promote their proliferation and neurogenesis in the hippocampus. Therefore, LIG has potential for use in the prevention and/or treatment of POCD.

Robust Antibody and T Cell Responses to SARS-CoV-2 in Patients with Antibody Deficiency.

Immunocompromised patients, including those with inborn errors of immunity (IEI), may be at increased risk for severe or prolonged infections with SARS-CoV-2 (Zhu et al. N Engl J Med. 382:727-33, 2020; Guan et al. 2020; Minotti et al. J Infect. 81:e61-6, 2020). While antibody and T cell responses to SARS-CoV-2 structural proteins are well described in healthy convalescent donors, adaptive humoral and cellular immunity has not yet been characterized in patients with antibody deficiency (Grifoni et al. Cell. 181:1489-1501 e1415, 2020; Burbelo et al. 2020; Long et al. Nat Med. 26:845-8, 2020; Braun et al. 2020). Herein, we describe the clinical course, antibody, and T cell responses to SARS-CoV-2 structural proteins in a cohort of adult and pediatric patients with antibody deficiencies (n = 5) and controls (related and unrelated) infected with SARS-CoV-2. Five patients within the same family (3 with antibody deficiency, 2 immunocompetent controls) showed antibody responses to nucleocapsid and spike proteins, as well as SARS-CoV-2 specific T cell immunity at days 65-84 from onset of symptoms. No significant difference was identified between immunocompromised patients and controls. Two additional unrelated, adult patients with common variable immune deficiency were assessed. One did not show antibody response, but both demonstrated SARS-CoV-2-specific T cell immunity when evaluated 33 and 76 days, respectively, following SARS-CoV-2 diagnosis. This report is the first to show robust T cell activity and humoral immunity against SARS-CoV-2 structural proteins in some patients with antibody deficiency. Given the reliance on spike protein in most candidate vaccines (Folegatti et al. Lancet. 396:467-78, 2020; Jackson et al. N Engl J Med. 383:1920-31, 2020), the responses are encouraging. Additional studies will be needed to further define the timing of onset of immunity, longevity of the immune response, and variability of response in immunocompromised patients.

Identification of novel HLA-restricted preferentially expressed antigen in melanoma peptides to facilitate off-the-shelf tumor-associated antigen-specific T-cell therapies.

BACKGROUND AIMS: Preferentially expressed antigen in melanoma (PRAME) is a cancer/testis antigen that is overexpressed in many human malignancies and poorly expressed or absent in healthy tissues, making it a good target for anti-cancer immunotherapy. Development of an effective off-the-shelf adoptive T-cell therapy for patients with relapsed or refractory solid tumors and hematological malignancies expressing PRAME antigen requires the identification of major histocompatibility complex (MHC) class I and II PRAME antigens recognized by the tumor-associated antigen (TAA) T-cell product. The authors therefore set out to extend the repertoire of HLA-restricted PRAME peptide epitopes beyond the few already characterized. METHODS: Peptide libraries of 125 overlapping 15-mer peptides spanning the entire PRAME protein sequence were used to identify HLA class I- and II-restricted epitopes. The authors also determined the HLA restriction of the identified epitopes. RESULTS: PRAME-specific T-cell products were successfully generated from peripheral blood mononuclear cells of 12 healthy donors. Ex vivo-expanded T cells were polyclonal, consisting of both CD4+ and CD8+ T cells, which elicited anti-tumor activity in vitro. Nine MHC class I-restricted PRAME epitopes were identified (seven novel and two previously described). The authors also characterized 16 individual 15-mer peptide sequences confirmed as CD4-restricted epitopes. CONCLUSIONS: TAA T cells derived from healthy donors recognize a broad range of CD4+ and CD8+ HLA-restricted PRAME epitopes, which could be used to select suitable donors for generating off-the-shelf TAA-specific T cells.

T-cell receptor sequencing demonstrates persistence of virus-specific T cells after antiviral immunotherapy.

Viral infections are a serious cause of morbidity and mortality following haematopoietic stem cell transplantation (HSCT). Adoptive cellular therapy with virus-specific T cells (VSTs) has been successful in preventing or treating targeted viruses in prior studies, but the composition of ex vivo expanded VST and the critical cell populations that mediate antiviral activity in vivo are not well defined. We utilized deep sequencing of the T-cell receptor beta chain (TCRB) in order to classify and track VST populations in 12 patients who received VSTs following HSCT to prevent or treat viral infections. TCRB sequencing was performed on sorted VST products and patient peripheral blood mononuclear cells samples. TCRB diversity was gauged using the Shannon entropy index, and repertoire similarity determined using the Morisita-Horn index. Similarity indices reflected an early change in TCRB diversity in eight patients, and TCRB clonotypes corresponding to targeted viral epitopes expanded in eight patients. TCRB repertoire diversity increased in nine patients, and correlated with cytomegalovirus (CMV) viral load following VST infusion (P = 0·0071). These findings demonstrate that allogeneic VSTs can be tracked via TCRB sequencing, and suggests that T-cell receptor repertoire diversity may be critical for the control of CMV reactivation after HSCT.

Characterization of natural killer cells expressing markers associated with maturity and cytotoxicity in children and young adults with sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) is increasingly recognized as a red blood cell disorder modulated by abnormally increased inflammation. We have previously shown that in patients with SCD not on a disease-modifying therapy (hydroxyurea or chronic transfusions), natural killer (NK) cell numbers are increased. In the current study, we further investigated the NK cell function to determine if there was evidence of increased activation and cytotoxicity. PROCEDURE: We conducted a cross-sectional study of 44 patients with HbSS/HbSß0 thalassemia at steady state (hydroxyurea = 13, chronic transfusion = 11, no disease-modifying therapy = 20) and 23 healthy controls. Using a fresh blood sample, NK immunophenotyping was performed as follows: NK cells (CD3- CD56+ lymphocytes) were evaluated for makers associated with activation (NKG2D, NKp30, NKp44, and CD69) and maturity (CD57, killer immunoglobulin-like receptors (KIR), and CD56dim). Degranulation and cytotoxicity assays were performed to evaluate NK cell function. RESULTS: Patients with SCD who were not on disease-modifying therapy had a higher number of NK cells with an immunophenotype associated with increased cytotoxicity (NKG2D+ , NKp30+ , CD56dim+ , and KIR+ NK cells) compared with healthy controls and patients on hydroxyurea. NK cells from SCD patients not on disease-modifying therapy demonstrated significantly increased cytotoxicity (measured by assaying NK cell killing of the K562 cell line) compared with healthy controls (P = 0.005). Notably, NK cell cytotoxicity against K562 cells in the hydroxyurea or chronic transfusion patients was not significantly different from that in healthy controls. CONCLUSION: SCD is associated with increased NK cell function as well as increased NK cell numbers, which appears to be normalized with disease-modifying therapy.

Antiviral T Cells for Adenovirus in the Pretransplant Period: A Bridge Therapy for Severe Combined Immunodeficiency.

Viral infections can be life threatening in patients with severe combined immunodeficiency (SCID) and other forms of profound primary immunodeficiency disorders both before and after hematopoietic stem cell transplantation (HSCT). Adoptive immunotherapy with virus-specific T cells (VSTs) has been utilized in many patients in the setting of HSCT, but has very rarely been attempted for treatment of viral infections before HSCT. Here we describe the use of VSTs in an infant with RAG1 SCID who had developed disseminated adenovirus which failed to improve on cidofovir. Adenovirus cleared following 2 doses of VSTs and marrow infusion from a matched unrelated donor, without incidence of graft versus host disease. T cell receptor-b sequencing demonstrated expansion of adenovirus-specific T cell fraction of the VSTs, suggesting that infusion facilitated viral clearance. This report suggests that VSTs are likely safe in the pre-HSCT period, and may be a useful bridge therapy for infants with SCID and persistent viral infections.

Alpha-Lipoic Acid Preconditioning and Ischaemic Postconditioning Synergistically Protect Rats from Cerebral Injury Induced by Ischemia and Reperfusion Partly via Inhibition TLR4/MyD88/ NF-κB Signaling Pathway.

BACKGROUND/AIMS: A combination of alpha-lipoic acid preconditioning (ALAP) and ischaemic preconditioning (IPC) has not been tested in an in vivo rat cerebral ischaemia/reperfusion injury (I/RI) model, and the potential protective mechanisms have not been well elucidated. The aim of this study was to investigate the role of the TLR4/ MyD88/ NF-κB signaling pathway in the synergistically neuroprotective and anti-inflammatory effects of ALAP and IPC. METHODS: One hundred and fifty male Sprague-Dawley rats, weighing 180-230 g, were randomly divided into the following 5 groups: 1) sham-operated control; 2) I/R; 3) I/R+ALAP; 4) I/R+IPC; 5) I/R+IPC+ALAP. After 2 h of reperfusion, the infarct size, neurological deficit scores, brain oedema, oxidative stress, and inflammatory and apoptotic biomarkers were assessed. In addition, reactive oxygen species (ROS) and cell apoptosis were detected by DHE staining and TUNEL staining, respectively. RESULTS: Both ALAP and IPC treatment attenuated the I/RI-induced neuronal injury, reflected by reductions in the infarct size, neurological deficit scores, brain oedema, lactate dehydrogenase (LDH) release and the inflammatory response, as well as decreased HMGB1, TLR4, MyD88, p65, C-Caspase 3 and Bax expression and increased IKB-α, HO-1, SOD-2 and Bcl-2 expression compared to that in the I/R group. Furthermore, the combination of the two strategies had synergistic anti-inflammatory effects and antioxidant benefits, ultimately limiting neuronal apoptosis. CONCLUSION: The 'cocktail' strategy exhibited a significant neuroprotection against I/RI by attenuating neuroinflammation via inhibition of the TLR4/MyD88/NF-κB signaling pathway.

Human papilloma virus-specific T cells can be generated from naïve T cells for use as an immunotherapeutic strategy for immunocompromised patients.

Human papilloma virus (HPV) is a known cause of cervical cancer, squamous cell carcinoma and laryngeal cancer. Although treatments exist for HPV-associated malignancies, patients unresponsive to these therapies have a poor prognosis. Recent findings from vaccine studies suggest that T-cell immunity is essential for disease control. Because Epstein-Barr Virus (EBV)-specific T cells have been highly successful in treating or preventing EBV-associated tumors, we hypothesized that the development of a manufacturing platform for HPV-specific T cells from healthy donors could be used in a third-party setting to treat patients with high-risk/relapsed HPV-associated cancers. Most protocols for generating virus-specific T cells require prior exposure of the donor to the targeted virus and, because the seroprevalence of high-risk HPV types varies greatly by age and ethnicity, manufacturing of donor-derived HPV-specific T cells has proven challenging. We, therefore, made systematic changes to our current Good Manufacturing Practice (GMP)-compliant protocols to improve antigen presentation, priming and expansion for the manufacture of high-efficacy HPV-specific T cells. Like others, we found that current methodologies fail to expand HPV-specific T cells from most healthy donors. By optimizing dendritic cell maturation and function with lipopolysaccharide (LPS) and interferon (IFN)γ, adding interleukin (IL)-21 during priming and depleting memory T cells, we achieved reliable expansion of T cells specific for oncoproteins E6 and E7 to clinically relevant amounts (mean, 578-fold expansion; n = 10), which were polyfunctional based on cytokine multiplex analysis. In the third-party setting, such HPV-specific T-cell products might serve as a potent salvage therapy for patients with HPV-associated diseases.

A risk score based on admission characteristics to predict progressive hemorrhagic injury from traumatic brain injury in children.

Traumatic brain injury (TBI) is one of the leading causes of death and disability in children, and progressive hemorrhagic injury (PHI) post TBI is associated with poor outcomes. Therefore, the objective of this study was to develop and validate a prognostic model that uses the information available at admission to determine the likelihood of PHI occurrence after TBI in children. The identified demographic data, cause of injury, clinical predictors on admission, computed tomography scan characteristics, and routine laboratory parameters were collected and used to develop a PHI prognostic model with logistic regression analysis, and the prediction model was validated in 68 children. Eight independent prognostic factors were identified: lower Glasgow coma scale score (3 ~ 8) (6 points), intra-axial bleeding/brain contusion (4 points), midline shift ≥5 mm (9 points), platelets <100 × 109/L (11 points), prothrombin time >14 s (6 points), international normalized ratio >1.25 (7 points), D-dimer ≥5 mg/L (14 points), and glucose ≧10 mmol/L (11 points). We calculated risk scores for each child and defined three risk groups: low risk (0-16 points), intermediate risk (17-36 points), and high risk (37-68 points). In the development cohort, the PHI rates after TBI for the low-, intermediate-, and high-risk groups were 10.1, 47.9, and 84.2%, respectively. In the validation cohort, the corresponding PHI rates were 10.9, 47.5, and 85.4%, respectively. The C-statistic for the point system was 0.873 (p = 0.586 by the Hosmer-Lemeshow test) in the development cohort and 0.877 (p = 0.524 by the Hosmer-Lemeshow test) in the validation cohort. CONCLUSION: Using admission predictors, we developed a relatively simple risk score that accurately predicted the risk of PHI after TBI in children. What is Known: • TBI is one of the leading causes of death and disability in children, and PHI post TBI is associated with poor outcomes. •Prediction of patients at low risk of PHI could help reduce treatment costs, whereas identification of patients at high risk of PHI could direct early medical intervention to improve outcomes. What is New: • This study firstly developed a risk score system by assessing the admission information that could provide an earlier prediction of the occurrence of PHI after acute TBI in children.

Human parainfluenza virus-3 can be targeted by rapidly ex vivo expanded T lymphocytes.

BACKGROUND AIMS: Human parainfluenza virus-3 (HPIV) is a common cause of respiratory infection in immunocompromised patients and currently has no effective therapies. Virus-specific T-cell therapy has been successful for the treatment or prevention of viral infections in immunocompromised patients but requires determination of T-cell antigens on targeted viruses. METHODS: HPIV3-specific T cells were expanded from peripheral blood of healthy donors using a rapid generation protocol targeting four HPIV3 proteins. Immunophenotyping was performed by flow cytometry. Viral specificity was determined by interferon (IFN)-γ ELISpot, intracellular cytokine staining and cytokine measurements from culture supernatants by Luminex assay. Cytotoxic activity was tested by 51Cr release and CD107a mobilization assays. Virus-specific T cells targeting six viruses were then produced by rapid protocol, and the phenotype of HPIV3-specific T cells was determined by immunomagnetic sorting for IFN-γ-producing cells. RESULTS: HPIV3-specific T cells were expanded from 13 healthy donors. HPIV3-specific T cells showed a CD4+ predominance (mean CD4:CD8 ratio 2.89) and demonstrated specificity for multiple HPIV3 antigens. The expanded T cells were polyfunctional based on cytokine production but only had a minor cytotoxic component. T cells targeting six viruses in a single product similarly showed HPIV3 specificity, with a predominant effector memory phenotype (CD3+/CD45RA-/CCR7-) in responder cells. DISCUSSION: HPIV3-specific T cells can be produced using a rapid ex vivo protocol from healthy donors and are predominantly CD4+ T cells with Th1 activity. HPIV3 epitopes can also be successfully targeted alongside multiple other viral epitopes in production of six-virus T cells, without loss of HPIV3 specificity. These products may be clinically beneficial to combat HPIV3 infections by adoptive T-cell therapy in immune-compromised patients.

Secondary bone marrow graft loss after third-party virus-specific T cell infusion: Case report of a rare complication.

Virus-specific T cells (VST) from partially-HLA matched donors have been effective for treatment of refractory viral infections in immunocompromised patients in prior studies with a good safety profile, but rare adverse events have been described. Here we describe a unique and severe adverse event of VST therapy in an infant with severe combined immunodeficiency, who receives, as part of a clinical trial (NCT03475212), third party VSTs for treating cytomegalovirus viremia following bone marrow transplantation. At one-month post-VST infusion, rejection of graft and reversal of chimerism is observed, as is an expansion of T cells exclusively from the VST donor. Single-cell gene expression and T cell receptor profiling demonstrate a narrow repertoire of predominantly activated CD4+ T cells in the recipient at the time of rejection, with the repertoire overlapping more with that of peripheral blood from VST donor than the infused VST product. This case thus demonstrates a rare but serious side effect of VST therapy.

Antiviral cellular therapy for enhancing T-cell reconstitution before or after hematopoietic stem cell transplantation (ACES): a two-arm, open label phase II interventional trial of pediatric patients with risk factor assessment.

Viral infections remain a major risk in immunocompromised pediatric patients, and virus-specific T cell (VST) therapy has been successful for treatment of refractory viral infections in prior studies. We performed a phase II multicenter study (NCT03475212) for the treatment of pediatric patients with inborn errors of immunity and/or post allogeneic hematopoietic stem cell transplant with refractory viral infections using partially-HLA matched VSTs targeting cytomegalovirus, Epstein-Barr virus, or adenovirus. Primary endpoints were feasibility, safety, and clinical responses (>1 log reduction in viremia at 28 days). Secondary endpoints were reconstitution of antiviral immunity and persistence of the infused VSTs. Suitable VST products were identified for 75 of 77 clinical queries. Clinical responses were achieved in 29 of 47 (62%) of patients post-HSCT including 73% of patients evaluable at 1-month post-infusion, meeting the primary efficacy endpoint (>52%). Secondary graft rejection occurred in one child following VST infusion as described in a companion article. Corticosteroids, graft-versus-host disease, transplant-associated thrombotic microangiopathy, and eculizumab treatment correlated with poor response, while uptrending absolute lymphocyte and CD8 T cell counts correlated with good response. This study highlights key clinical factors that impact response to VSTs and demonstrates the feasibility and efficacy of this therapy in pediatric HSCT.

Small extracellular vesicles secreted by induced pluripotent stem cell-derived mesenchymal stem cells improve postoperative cognitive dysfunction in mice with diabetes.

Postoperative cognitive dysfunction (POCD) is a common surgical complication. Diabetes mellitus (DM) increases risk of developing POCD after surgery. DM patients with POCD seriously threaten the quality of patients' life, however, the intrinsic mechanism is unclear, and the effective treatment is deficiency. Previous studies have demonstrated neuronal loss and reduced neurogenesis in the hippocampus in mouse models of POCD. In this study, we constructed a mouse model of DM by intraperitoneal injection of streptozotocin, and then induced postoperative cognitive dysfunction by transient bilateral common carotid artery occlusion. We found that mouse models of DM-POCD exhibited the most serious cognitive impairment, as well as the most hippocampal neural stem cells (H-NSCs) loss and neurogenesis decline. Subsequently, we hypothesized that small extracellular vesicles secreted by induced pluripotent stem cell-derived mesenchymal stem cells (iMSC-sEVs) might promote neurogenesis and restore cognitive function in patients with DM-POCD. iMSC-sEVs were administered via the tail vein beginning on day 2 after surgery, and then once every 3 days for 1 month thereafter. Our results showed that iMSC-sEVs treatment significantly recovered compromised proliferation and neuronal-differentiation capacity in H-NSCs, and reversed cognitive impairment in mouse models of DM-POCD. Furthermore, miRNA sequencing and qPCR showed miR-21-5p and miR-486-5p were the highest expression in iMSC-sEVs. We found iMSC-sEVs mainly transferred miR-21-5p and miR-486-5p to promote H-NSCs proliferation and neurogenesis. As miR-21-5p was demonstrated to directly targete Epha4 and CDKN2C, while miR-486-5p can inhibit FoxO1 in NSCs. We then demonstrated iMSC-sEVs can transfer miR-21-5p and miR-486-5p to inhibit EphA4, CDKN2C, and FoxO1 expression in H-NSCs. Collectively, these results indicate significant H-NSC loss and neurogenesis reduction lead to DM-POCD, the application of iMSC-sEVs may represent a novel cell-free therapeutic tool for diabetic patients with postoperative cognitive dysfunction.

Outcomes following posttransplant virus-specific T-cell therapy in patients with sickle cell disease.

Hematopoietic stem cell transplantation (HSCT) is being increasingly used as a curative approach for sickle cell disease (SCD). With the risk of graft-versus-host disease (GVHD), especially in the human leukocyte antigen-mismatched donors, intense immunosuppression is required leading to an increased risk of viral infection. Post-HSCT, adoptive transfer of virus-specific T-cell (VST) therapies have not been well-studied in patients with SCD. Here, we report the outcomes of patients with SCD at a single-center who received VSTs after transplant to prevent or treat viral infections. Thirteen patients who received HSCT from human leukocyte antigen-matched (n = 9) or -mismatched (n = 4) donors for SCD were treated with a total of 15 VST products for the treatment or prophylaxis of multiple viruses (cytomegalovirus, Epstein-Barr virus, adenovirus, BK virus, human herpes virus 6 +/- human parainfluenza virus 3). Of the patients evaluated, 46.2% (n = 6)) received VSTs as treatment for viral infection. Eighty percent of patients with active viremia (n = 4/5) achieved remission of at least 1 target virus. Seven additional patients (53.8%) received VSTs prophylactically and 6 of 7 (85.7%) remained virus-free after infusion. No immediate infusion-related toxicities occurred, and severe de novo acute GVHD occurred in only 2 (15.4%) patients. Given the good safety profile, high-rate of clinical responses and sustained remissions when administered with standard antiviral treatments, the routine use of VSTs after HSCT as prophylaxis or treatment may improve the overall safety of transplant for patients with SCD.

Co-transducing B7H3 CAR-NK cells with the DNR preserves their cytolytic function against GBM in the presence of exogenous TGF-ß.

Cord blood (CB)-derived natural killer (NK) cells that are genetically engineered to express a chimeric antigen receptor (CAR) are an attractive off-the-shelf therapy for the treatment of cancer, demonstrating a robust safety profile in vivo. For poor prognosis brain tumors such as glioblastoma multiforme (GBM), novel therapies are urgently needed. Although CAR-T cells demonstrate efficacy in preclinical GBM models, an off-the-shelf product may exhibit unwanted side effects like graft-versus-host disease. Hence, we developed an off-the-shelf CAR-NK cell approach using a B7H3 CAR and showed that CAR-transduced NK cells have robust cytolytic activity against GBM cells in vitro. However, transforming growth factor (TGF)-ß within the tumor microenvironment has devastating effects on the cytolytic activity of both unmodified and CAR-transduced NK cells. To overcome this potent immune suppression, we demonstrated that co-transducing NK cells with a B7H3 CAR and a TGF-ß dominant negative receptor (DNR) preserves cytolytic function in the presence of exogenous TGF-ß. This study demonstrates that a novel DNR and CAR co-expression strategy may be a promising therapeutic for recalcitrant CNS tumors like GBM.

Transcriptomic analysis reveals optimal cytokine combinations for SARS-CoV-2-specific T cell therapy products.

Adoptive T cell immunotherapy has been used to restore immunity against multiple viral targets in immunocompromised patients after bone-marrow transplantation and has been proposed as a strategy for preventing coronavirus 2019 (COVID-19) in this population. Ideally, expanded severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-virus-specific T cells (CSTs) should demonstrate marked cell expansion, T cell specificity, and CD8+ T cell skewing prior to adoptive transfer. However, current methodologies using IL-4 + IL-7 result in suboptimal specificity, especially in CD8+ cells. Using a microexpansion platform, we screened various cytokine cocktails (IL-4 + IL-7, IL-15, IL-15 + IL-4, IL-15 + IL-6, and IL-15 + IL-7) for the most favorable culture conditions. IL-15 + IL-7 optimally balanced T cell expansion, polyfunctionality, and CD8+ T cell skewing of a final therapeutic T cell product. Additionally, the transcriptomes of CD4+ and CD8+ T cells cultured with IL-15 + IL-7 displayed the strongest induction of antiviral type I interferon (IFN) response genes. Subsequently, microexpansion results were successfully translated to a Good Manufacturing Practice (GMP)-applicable format where IL-15 + IL-7 outperformed IL-4 + IL-7 in specificity and expansion, especially in the desirable CD8+ T cell compartment. These results demonstrate the functional implications of IL-15-, IL-4-, and IL-7-containing cocktails for therapeutic T cell expansion, which could have broad implication for cellular therapy, and pioneer the use of RNA sequencing (RNA-seq) to guide viral-specific T cell (VST) product manufacturing.