Adoptive therapy with regulatory T cells (Tregs) to prevent graft-versus-host disease (GVHD) would benefit from a strategy to improve homing to the sites of inflammation. We hypothesized that adding ...fucose to human Tregs, forming the Sialyl Lewis X moiety on P-selectin glycoprotein ligand-1, would improve their trafficking pattern. The selectin pathway recruiter, α-1,3-fucosyltransferase-VI enzyme, significantly increased Treg surface fucosylation (66% vs 8%). In a xenogenic GVHD mouse model, fucosylated Tregs showed prolonged periods of in vivo persistence. When given at a lower dose compared with the untreated Tregs, the murine recipients of fucosylated Tregs maintained weight, had ameliorated clinical GVHD, and improved survival (70% vs 30%; P < .0001). These preclinical data indicate that fucosylated human Tregs is an effective strategy for prevention of GVHD and, as such, warrants consideration for future clinical trials.
•Fucosylated Tregs persist for a longer time in vivo.•Fucosylated Tregs are able to prevent GVHD at a lower cell dose compared with untreated Tregs.
Background
There have been concerns regarding increased peritransplantation complications, especially severe acute graft‐versus‐host disease (aGVHD), in patients with prior use of checkpoint ...inhibitors (CPI) before hematopoietic stem cell transplantation (HSCT).
Methods
The authors performed a retrospective study of 43 patients with acute myeloid leukemia and/or myelodysplastic syndromes who were treated with an antiprogrammed cell death protein 1 (PD‐1) (32 patients) or anticytotoxic T‐lymphocyte–associated protein 4 (CTLA‐4) (9 patients) blockade or both (2 patients) prior to HSCT with the primary outcome of aGVHD by day 100 after HSCT. Outcome analyses were stratified by GVHD prophylaxis as use of post‐HSCT cyclophosphamide (PTCy) (22 patients) or not (non‐PTCy) (21 patients).
Results
The PTCy group demonstrated a trend toward lower grade 3 to 4 aGVHD when compared with the non‐PTCy group (5% vs 22%), although the rates of grade 2 to 4 aGVHD were comparable (49% vs 56%). The interval between CPI and HSCT did not appear to impact the incidence of aGVHD. However, a higher incidence of grade 3 to 4 aGVHD was observed in patients who received >4 treatments of CPI prior to HSCT if they were not given PTCy as GVHD prophylaxis (43% vs 12%). Matched control analyses using patients with no prior use of CPI confirmed the increase in grade 3 to 4 aGVHD with those agents. However, that increased risk was limited to patients who did not receive PTCy and was not observed in patients who received PTCy as GVHD prophylaxis. Despite persistent improvement in GVHD with the use of PTCy, disease control was not compromised and progression‐free survival at 1 year was found to be superior for patients treated with PTCy compared with those not receiving PTCy among patients with prior use of CPI (55% vs 22%).
Conclusions
The results of the current study indicated that HSCT with prior use of CPI appears feasible in patients with acute myeloid leukemia and/or myelodysplastic syndromes and the use of PTCy as GVHD prophylaxis improves outcomes.
The use of checkpoint inhibitors (CPI) prior to hematopoietic stem cell transplantation (HSCT) in patients with acute myeloid leukemia and/or myelodysplastic syndromes affects transplantation outcomes, with an especially increased incidence of grade 3 to 4 acute graft‐versus‐host disease (aGVHD). The use of post‐HSCT cyclophosphamide as GVHD prophylaxis in patients treated with CPI prior to transplantation is found to lead to improved transplantation outcomes, including grade 3 to 4 aGVHD.
The ability to distinguish allogeneic hematopoietic cell transplant (allo-HCT) recipients at risk for cytomegalovirus (CMV) reactivation from those who are not is central for optimal CMV management ...strategies. Interferon γ (IFN-γ) produced by CMV-challenged T cells may serve as an immune marker differentiating these 2 populations. We prospectively monitored 63 CMV-seropositive allo-HCT recipients with a CMV-specific enzyme-linked immunospot (ELISPOT) assay and for CMV infection from the period before transplantation to day 100 after transplantation. Assay results above certain thresholds (50 spots per 250 000 cells for immediate early 1 or 100 spots per 250 000 cells for phosphoprotein 65) identified patients who were protected against CMV infection as long as they had no graft-versus-host disease and/or were not receiving systemic corticosteroids. Based on the multivariable Cox proportional hazards regression model, the only significant factor for preventing CMV reactivation was a CMV-specific ELISPOT response above the determined thresholds (adjusted hazard ratio, 0.21; 95% confidence interval, .05–.97; P = .046). Use of this assay as an additional tool for managing allo-HCT recipients at risk for CMV reactivation needs further validation in future studies. Application of this new approach may reduce the duration and intensity of CMV monitoring and the duration of prophylaxis or treatment with antiviral agents in those who have achieved CMV-specific immune reconstitution.
Neuroinflammation is a pathological hallmark of ALS in both transgenic rodent models and patients, and is characterized by proinflammatory T lymphocytes and activated macrophages/microglia. In ALS ...mouse models, decreased regulatory T lymphocytes (Tregs) exacerbate the neuroinflammatory process, leading to accelerated motoneuron death and shortened survival; passive transfer of Tregs suppresses the neuroinflammation and prolongs survival. Treg numbers and FOXP3 expression are also decreased in rapidly progressing ALS patients. A key question is whether the marked neuroinflammation in ALS can be attributed to the impaired suppressive function of ALS Tregs in addition to their decreased numbers. To address this question, T lymphocyte proliferation assays were performed. Compared with control Tregs, ALS Tregs were less effective in suppressing responder T lymphocyte proliferation. Although both slowly and rapidly progressing ALS patients had dysfunctional Tregs, the greater the clinically assessed disease burden or the more rapidly progressing the patient, the greater the Treg dysfunction. Epigenetically, the percentage methylation of the Treg-specific demethylated region was greater in ALS Tregs. After in vitro expansion, ALS Tregs regained suppressive abilities to the levels of control Tregs, suggesting that autologous passive transfer of expanded Tregs might offer a novel cellular therapy to slow disease progression.
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