Cytomegalovirus infection in mesenchymal stem cells and their activation could be enhanced by nuclear factor-κB inhibitor pyrrolidinedithiocarbamate in vitro

Protective and pathological roles of regulatory immune cells in human cytomegalovirus infection following hematopoietic stem cell transplantation

Human cytomegalovirus (HCMV) is ubiquitously prevalent. Immune system in healthy individuals is capable of controlling HCMV infection; however, HCMV can be life-threatening for immunocompromised individuals, such as transplant recipients. Both innate and adaptive immune systems are critically involved in the HCMV infection. Recent studies have indicated that regulatory immune cells which play essential roles in maintaining a healthy immune environment are closely related to immune response in HCMV infection. However, the exact role of regulatory immune cells in immune regulation and homoeostasis during the battle between HCMV and host still requires further research. In this review, we highlight the protective and pathological roles of regulatory immune cells in HCMV infection following hematopoietic stem cell transplantation (HSCT).

Detection of HTLV-1 proviral DNA in BM mononuclear cells and cultured mesenchymal stromal cells isolated from patients with HTLV-1 infection

The bone marrow (BM) biology during HTLV-1 infection is obscure. In this study, we investigated BM mononuclear cells and mesenchymal stromal cells (MSC) from HTLV-1 asymptomatic and symptomatic individuals. An infiltration of CD4⁺ T-cell lymphocytes in the BM of HTLV-1-infected individuals was observed when compared to healthy controls. The provirus detection in the BM CD4⁺ T cells confirmed the presence of integrated HTLV DNA. In regard to MSC, we observed that the number of fibroblast progenitor cells was lower in HTLV-1 infected individuals than in healthy controls. Isolated HTLV-1 infected BM-MSC demonstrated surface expression markers and in vitro differentiation potential similar to uninfected individuals. The presence of HTLV-1 proviral DNA in the BM-MSC of HTLV-1-infected patients was demonstrated but no p19 antigen was detected in supernatant from cultured MSC. We suppose that HTLV-1 infects human MSC probably by cell-to-cell contact from the infected CD4⁺ T-lymphocytes infiltrated into the bone marrow.

Allogeneic Bone Marrow-Derived Mesenchymal Stromal Cells Expanded In Vitro for Treatment of Aplastic Anemia: A Multicenter Phase II Trial

We conducted a phase II, noncomparative, multicenter study to assess the efficacy and safety of allogeneic bone marrow‐derived mesenchymal stromal cells (BM‐MSCs) expanded in vitro for patients with aplastic anemia (AA) refractory to immunosuppressive therapy. Seventy‐four patients from seven centers received allogeneic BM‐MSCs at a dose of 1–2 × 10⁶ cells/kg per week for 4 weeks. Responses were assessed at 0.5, 1, 2, 3, 6, 9, and 12 months after the first cells infusion. Patients with response at 1 month continued to receive four infusions. All patients were evaluable. The overall response rate was 28.4% (95% confidence interval, 19%–40%), with 6.8% complete response and 21.6% partial response. The median times to response of leukocytic, erythrocytic, and megakaryocytic linages were 19 (range, 11–29), 17 (range, 12–25), and 31 (range, 26–84) days, respectively. After median follow‐up of 17 months, overall survival was 87.8%. Seven patients developed transitory and mild headache and fever, but no other adverse events were observed. Antithymocyte globulin used in previous treatment and no activated infection throughout treatment were predictors for response. Allogeneic BM‐MSCs infusion is a feasible and effective treatment option for refractory AA. The trial was registered at www.clinicaltrials.gov as NCT00195624. Stem Cells Translational Medicine2017;6:1569–1575