Significance of alveolar nitric oxide concentration in the airway of patients with organizing pneumonia after allogeneic hematopoietic stem cell transplantation.

Organizing pneumonia (OP) is a complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) and a manifestation of peripheral airway/alveolar inflammation. Recently, alveolar nitric oxide concentration (Calv) has been revealed as a noninvasive marker of peripheral airway inflammation; however, whether Calv levels are associated with OP and peripheral airway in patients after allo-HSCT remains unclear. Herein, we evaluated whether Calv levels could reflect the presence of OP and structural airway changes in patients after allo-HSCT. We measured the eNO levels of 38 patients (6 with OP and 32 without OP) who underwent allo-HSCT. Three-dimensional computed tomography (CT) analysis of the airway was performed in 19 patients. We found that in patients with OP, Calv levels were significantly higher than in those without OP (10.6 vs. 5.5 ppb, p < 0.01). Receiver-operating characteristic analyses revealed a Calv cut-off value for OP detection of 10.2 ppb. No significant differences in the patient characteristics, except for the presence of OP (p < 0.01), were noted between the two groups stratified by the Calv cut-off value. Three-dimensional CT images of the airway revealed gradually increasing positive correlations between Calv levels and airway wall area of the third-, fourth-, and fifth-generation bronchi (r = 0.20, 0.31, 0.38; p = 0.42, 0.19, 0.038, respectively), indicating that Calv levels are strongly correlated with the wall thickness of the distal bronchi. Our results suggest that the Calv level may be a useful noninvasive detectable marker for OP after an allo-HSCT.

[Cancer Immunotherapy Using Gene Modification Technology].

Recently, accumulating discoveries in the field of immunology have been applied in clinical settings along with rapid progression of basic and pre-clinical research. Especially, advancement of gene modification technologies has contributed to unlock a way to novel cancer immunotherapy. One representative is chimeric antigen receptor-expressing T(CAR-T)cell therapy which was approved by FDA in August, 2017 as first gene-modified cell therapy. However, such technologies are still work-in-progress and there are many obstacles to be overcome for their full development. So called 4th generation CAR-T cells, in which CAR-T cells are engineered to secrete some kinds of cytokine and/or chemokine, have revealed their prominent potential to eradicate established solid tumors, which are usually resistant to conventional CAR-T cells. Another example of gene-modified cells for cancer immunotherapy is T cell receptor(TCR)-T cells, which are T cells engineered to express tumor antigen-specific TCR. Targeting neoantigens, mutated proteins to be expressed only in cancer cells and scarcely in normal ones, is attracting attempt for TCR-T cell approach. In addition, due to unique immunological functions, other lymphocyte subsets such as natural killer(NK)cells, invariant natural killer T(iNKT)cells, and gd-type T cells gain attention as effector cells to be gene-modified. Furthermore, off-the-shelf cell therapy, in which patients receive cell products made from allogeneic non-self immune cells, is nowunder development. It should be noted that development of "personalized" medicine, which aims to customize drugs to be suitable for each patient and different types of tumor, and "universal" technologies, which are crucial to generate uniform quality of cell products and to decrease manufacturing time and cost, are highly important for further advance of cancer immunotherapy.

Therapeutic effects of anti-GM2 CAR-T cells expressing IL-7 and CCL19 for GM2-positive solid cancer in xenograft model.

BACKGROUND: While chimeric antigen receptor (CAR)-T cell therapy has demonstrated excellent efficacy in hematopoietic malignancies, its clinical application in solid cancers has yet to be achieved. One of the reasons for such hurdle is a lack of suitable CAR targets in solid cancers. METHODS: GM2 is one of the gangliosides, a group of glycosphingolipids with sialic acid in the glycan, and overexpressed in various types of solid cancers. In this study, by using interleukin (IL)-7 and chemokine (C-C motif) ligand 19 (CCL19)-producing human CAR-T system which we previously developed, a possibility of GM2 as a solid tumor target for CAR-T cell therapy was explored in a mouse model with human small-cell lung cancer. RESULTS: Treatment with anti-GM2 IL-7/CCL19-producing CAR-T cells induced complete tumor regression along with an abundant T cell infiltration into the solid tumor tissue and long-term memory responses, without any detectable adverse events. In addition, as measures to control cytokine-release syndrome and neurotoxicity which could occur in association with clinical use of CAR-T cells, we incorporated Herpes simplex virus-thymidine kinase (HSV-TK), a suicide system to trigger apoptosis by administration of ganciclovir (GCV). HSV-TK-expressing anti-GM2 IL-7/CCL19-producing human CAR-T cells were efficiently eliminated by GCV administration in vivo. CONCLUSIONS: Our study revealed the promising therapeutic efficacy of anti-GM2 IL-7/CCL19-producing human CAR-T cells with an enhanced safety for clinical application in the treatment of patients with GM2-positive solid cancers.

Enhanced Antitumor Responses of Tumor Antigen-Specific TCR T Cells Genetically Engineered to Produce IL7 and CCL19.

Although adoptive transfer of T cells genetically engineered to express chimeric antigen receptor (CAR) or T-cell receptor (TCR) has been actively developed and applied into clinic recently, further improvement of these modalities is highly demanded, especially in terms of its efficacy. Because we previously revealed the profound enhancement of antitumor effects of CAR T cells by concomitant expression of IL7 and CCL19, this study further explored a potential of IL7/CCL19 production technology to augment antitumor effects of TCR T cells. IL7/CCL19-producing P1A tumor antigen-specific TCR T cells (7 × 19 P1A T cells) demonstrated significantly improved antitumor effects, compared with those without IL7/CCL19 production, and generated long-term memory responses. The antitumor effects of 7×19 P1A T cells were further upregulated by combination with anti-PD-1 antibody, in which blockade of PD-1 signal in both 7×19 P1A T cells and endogenous T cells plays an important role. Taken together, our study demonstrated that concomitant production of IL7 and CCL19 by genetically engineered tumor-reactive T cells could synergize with PD-1 blockade therapy to generate potent and long-lasting antitumor immunity.

Soluble Interleukin-2 Receptor Index Predicts Outcomes After Cord Blood Transplantation.

BACKGROUND: Our previous study demonstrated that the soluble interleukin-2 receptor (sIL-2R) index, defined as the ratio of serum sIL-2R levels at neutrophil engraftment to that before conditioning, is a biomarker that can predict acute graft-vs-host disease (GVHD) after unrelated bone marrow transplantation. In the present study, we evaluated the significance of the sIL-2R index among patients who underwent cord blood transplantation (CBT). METHODS: We retrospectively analyzed 31 patients who underwent single-unit CBT as their first transplantation for hematologic malignancies. RESULTS: The median sIL-2R index was 4.2. The cumulative incidence of grade II to IV acute GVHD was not associated with the sIL-2R index. However, the cumulative incidence of relapse at 3 years after transplantation was significantly lower, with an sIL-2R index ≥ 3.7 than with an index < 3.7 (12.8% vs 50.0%; P = .04). As a result, the probability of overall survival at 3 years after transplantation was significantly higher in the former group than in the latter (79.8% vs 20.0%; P < .01). Only the dose of corticosteroid administered in the pre-engraftment period influenced the sIL-2 index. CONCLUSION: The sIL-2R index can predict the incidence of relapse and probability of survival after CBT, possibly reflecting a graft-vs-leukemia effect.

TERT and JAK2 polymorphisms define genetic predisposition to myeloproliferative neoplasms in Japanese patients.

Myeloproliferative neoplasms (MPNs), including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), are often characterized by specific somatic mutations in any of the three genes: JAK2, CALR, or MPL. A single nucleotide polymorphism (SNP), rs2736100, in the reverse transcriptase gene (TERT) and a germline JAK2 46/1 haplotype have been associated with MPNs in North American and European patients. We examined 201 Japanese MPN patients, including 52 with PV, 131 with ET, and 18 with PMF, as well as 366 control individuals for TERT rs2736100 and JAK2 rs10974944, a tagging SNP of the 46/1 haplotype. Furthermore, correlations between the JAK2 V617F allele burden at diagnosis and TERT rs2736100 or JAK2 rs10974944 were evaluated using a digital PCR assay for accurate quantitation. The JAK2 46/1 haplotype, but not the TERT rs2736100 SNP, was correlated to the JAK2 V617F mutant allele burden in JAK2 V617F-positive MPN patients. In conclusion, we demonstrated that both TERT rs2736100_C and JAK2 46/1 haplotype are predisposing factors for MPNs in Japanese patients. While TERT rs2736100_C tended to have a more general, non-specific effect on all MPNs, the JAK2 46/1 haplotype was essentially predisposed to the JAK2 V617F-positive MPNs.

Successful Treatment of Behçet's Disease Associated with Acute Myeloid Leukemia with Myelodysplasia-related Changes Using Azacitidine and Tacrolimus before Allogeneic Hematopoietic Stem Cell Transplantation.

The coexistence of acute myeloid leukemia (AML) with Behçet's disease (BD) is rare. The optimum treatment for AML-associated BD has not been established. We herein report a patient with BD who developed AML with myelodysplasia-related changes. Induction chemotherapy caused complete remission of the AML but worsened the BD. Thereafter, AML was treated with azacitidine. The BD was steroid-dependent. Tacrolimus was added, which improved the BD. The patient underwent allogeneic hematopoietic stem cell transplantation (HSCT) and remains in complete remission for both diseases. Allogeneic HSCT was found to be a potent therapeutic option for AML-associated BD. In addition, azacitidine and tacrolimus were shown to be a suitable bridging regimen before HSCT.

Soluble interleukin-2 receptor index predicts the development of acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation from unrelated donors.

Acute graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT) is associated with significant morbidity and mortality. In the present study, we retrospectively evaluated whether soluble interleukin-2 receptor (sIL-2R) index, defined as the ratio of serum sIL-2R levels at neutrophil engraftment to those at the pre-conditioning regimen, was predictive of acute GVHD among 51 patients who underwent allogeneic HSCT as their first transplantation and achieved engraftment. The median sIL-2R index was 3.6, and the sIL-2R values were positively associated with acute GVHD severity (grade 0-I: 3.8 ± 2.0 vs. grade II-IV: 7.1 ± 5.7; P = 0.05). Grade II-IV acute GVHD had a cumulative incidence of 31.4 %, and was significantly more frequent among patients with an sIL-2R index of ≥4.5 (≥4.5: 50.0 % vs. <4.5: 21.2 %; P = 0.03). Multivariate analysis revealed that an sIL-2R index of ≥4.5 [hazard ratio (HR) 3.5, P < 0.01] and donor age of >35 years (HR 3.8, P = 0.02) were significant risk factors for grade II-IV acute GVHD. Therefore, increased sIL-2R levels from baseline to engraftment might predict the risk of moderate-to-severe acute GVHD after allogeneic HSCT from an unrelated donor.