Level of Granzyme B-positive T-regulatory cells is a strong predictor biomarker of acute Graft-versus-host disease after day +30 after allo-HSCT

Interaction Networks Converging on Immunosuppressive Roles of Granzyme B: Special Niches Within the Tumor Microenvironment

Granzyme B is a renowned effector molecule primarily utilized by CTLs and NK cells against ill-defined and/or transformed cells during immunosurveillance. The overall expression of granzyme B within tumor microenvironment has been well-established as a prognostic marker indicative of priming immunity for a long time. Until recent years, increasing immunosuppressive effects of granzyme B are unveiled in the setting of different immunological context. The accumulative evidence confounded the roles of granzyme B in immune responses, thereby arousing great interests in characterizing detailed feature of granzyme B-positive niche. In this paper, the granzyme B-related regulatory effects of major suppressor cells as well as the tumor microenvironment that defines such functionalities were longitudinally summarized and discussed. Multiplex networks were built upon the interactions among different transcriptional factors, cytokines, and chemokines that regarded to the initiation and regulation of granzyme B-mediated immunosuppression. The conclusions and prospect may facilitate better interpretations of the clinical significance of granzyme B, guiding the rational development of therapeutic regimen and diagnostic probes for anti-tumor purposes.

High expression of granzyme B in conventional CD4+ T cells is associated with increased relapses after allogeneic stem cells transplantation in patients with hematological malignancies

Granzyme B is known to be a serine protease contained in granules of cytotoxic T cells. We have previously reported an influence of granzyme B expression in T regulatory cells (Tregs) on the risk of acute graft versus host disease (GVHD) onset. However, it is still unknown if conventional T cells (Tcon) use the granzyme B pathway as a mechanism of alloimmunity. We hypothesized that granzyme B in Tcon may affect recurrence within the first 6 months after allogeneic transplantation (allo-HSCT). A total of 65 patients with different hematological malignancies were included in this study. Blood samples were collected on day +30 after allo-HSCT. The percentage of granzyme B positive conventional T cells in patients who developed relapse in the first 6 months after allo-HSCT was 11.3 (4.5-35.3) compared to the others in continuous complete remission-1.3 (3.65-9.7), р = 0.011. The risk of relapse after allo-HSCT was in 3.9 times higher in patients with an increased percentage of granzyme B positive conventional T cells. The findings demonstrated that the percentage of granzyme B positive conventional T cells on day +30 after allo-HSCT could be a predictable marker of relapse within the first 6 months after allo-HSCT.

A distinct glycerophospholipid metabolism signature of acute graft versus host disease with predictive value

BACKGROUND

Acute graft-versus-host disease (aGvHD) is a major factor that limits the successful outcomes of allogeneic hematopoietic cell transplantation (alloHSCT). Currently there are few validated biomarkers that can help predict the risk of aGvHD in clinical settings.

METHODS

We performed an integrated metabolomics and transcriptomics study and identified biomarkers that distinguish alloHSCT recipients with aGvHD from alloHSCT recipients without aGvHD in two separate cohorts.

RESULTS

Pathway analysis of 38 significantly altered metabolites and 1148 differentially expressed genes uncovered a distinctly altered glycerophospholipid (GPL) metabolism network. Subsequently, we developed an aGvHD risk score (GRS) based on 5 metabolites markers from GPL metabolism to predict the risk of aGvHD. GRS showed a positive predictive value of 92.2% and 89.6% in the training and validation cohorts, respectively. In addition, high GRS was correlated with poor overall survival. Gene expressions of GPL-related lipases were significantly altered in aGvHD samples, leading to dysregulated GPLs.

CONCLUSIONS

Using integrative "Omic" analysis, we unraveled a comprehensive view of the molecular perturbations underlying the pathogenesis of aGvHD. Our work represents an initial investigation of a unique metabolic and transcriptomic network that may help identify aGvHD at an early stage and facilitate preemptive therapy.

FUNDING

National Natural Science Foundation of China (NSFC; 81530047, 81870143, 81470321, 81770160, 81270567, 81270638, 81573396, 81703674). Shanghai Sailing Program from Science and Technology Commission Shanghai Municipality (17YF1424700). Scholarship from Shanghai Municipal Health and Family Planning Commission (2017BR012). Special Clinical Research in Health Industry in Shanghai (20184Y0054).

Combining Flow and Mass Cytometry in the Search for Biomarkers in Chronic Graft-versus-Host Disease

Chronic graft-versus-host disease (cGVHD) is a debilitating complication arising in around half of all patients treated with an allogeneic hematopoietic stem cell transplantation. Even though treatment of severe cGVHD has improved during recent years, it remains one of the main causes of morbidity and mortality in affected patients. Biomarkers in blood that could aid in the diagnosis and classification of cGVHD severity are needed for the development of novel treatment strategies that can alleviate symptoms and reduce the need for painful and sometimes complicated tissue biopsies. Methods that comprehensively profile complex biological systems such as the immune system can reveal unanticipated markers when used with the appropriate methods of data analysis. Here, we used mass cytometry, flow cytometry, enzyme-linked immunosorbent assay, and multiplex assays to systematically profile immune cell populations in 68 patients with varying grades of cGVHD. We identified multiple subpopulations across T, B, and NK-cell lineages that distinguished patients with cGVHD from those without cGVHD and which were associated in varying ways with severity of cGVHD. Specifically, initial flow cytometry demonstrated that patients with more severe cGVHD had lower mucosal-associated T cell frequencies, with a concomitant higher level of CD38 expression on T cells. Mass cytometry could identify unique subpopulations specific for cGVHD severity albeit with some seemingly conflicting results. For instance, patients with severe cGVHD had an increased frequency of activated B cells compared to patients with moderate cGVHD while activated B cells were found at a reduced frequency in patients with mild cGVHD compared to patients without cGVHD. Moreover, results indicate it may be possible to validate mass cytometry results with clinically viable, smaller flow cytometry panels. Finally, no differences in levels of blood soluble markers could be identified, with the exception for the semi-soluble combined marker B-cell activating factor/B cell ratio, which was increased in patients with mild cGVHD compared to patients without cGVHD. These findings suggest that interdependencies between such perturbed subpopulations of cells play a role in cGVHD pathogenesis and can serve as future diagnostic and therapeutic targets.