Immune Dysfunction in Non-Hodgkin Lymphoma: Avenues for New Immunotherapy-Based Strategies

Helicobacter pylori infection disturbs the tumor immune microenvironment and is associated with a discrepant prognosis in gastric de novo diffuse large B-cell lymphoma

BACKGROUND

Gastric diffuse large B-cell lymphoma (gDLBCL) related to Helicobacter pylori infection exhibits a wide spectrum of prognosis, and the tumor immune microenvironment (TIME) affects tumor progression. However, there are few studies on the correlation between prognosis and changes of TIME induced by H. pylori infection in de novo gDLBCL.

METHODS

A retrospective study was performed to determine the prognostic value of TIME related to H. pylori infection in de novo gDLBCL. A total of 252 patients were included and have been treated with standard rituximab to cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy or other similar regimens in addition to H. pylori eradication (HPE). All patients were stratified by H. pylori infection, HPE efficacy, and preliminary TIME evaluation using conventional criteria. Statistical analyses were conducted. To assess the mechanism, 30 subjects were assessed for H. pylori infection. The components and spatial distributions of TIME were analyzed.

RESULTS

The median follow-up of the 252 patients was 66.6 months (range 0.7-119.2), and the 5-year overall survival (OS) was 78.0%. A total of 109 H. pylori-positive cases with pathological complete remission and high tumor-infiltrating T lymphocytes (cohort 1) had significantly higher 5-year progression-free survival (88.1% vs 70.5%, p<0.001) and OS (89.2% vs 76.6%, p<0.001) than the other 143 patients (cohort 2). Among 30 patients, 19 were cytotoxin-associated gene A-marked as the cohort 1 subset. Compared with cohort 2, cohort 1 exhibited increased inflammatory factors (tumor necrosis factor-α, interferon γ, etc) and decreased immunosuppressive components (PD-L1, PD-1, IL-10, etc). There was reduced NF-kB activation. Cancer-promoting immune cells (PD-1hiTim-3+ CTL, Tregs, M2-like macrophages, etc) occupied a minor spatial distribution, while the antitumor subtypes increased, corresponding to favorable survival.

CONCLUSION

H. pylori-evoked inflammatory responses disturb the TIME, causing a differential prognosis in de novo gDLBCL, which can be used to identify patients who could benefit from HPE and immunochemotherapy.

Expression and significance of CD47, PD1 and PDL1 in T-cell acute lymphoblastic lymphoma/leukemia

Although dose intensification strategies achieve a favorable prognosis for pediatric patients of T-lmphoblastic lymphoma/leukemia (T-LBL/ALL), numerous side effects have been followed. Molecular targeted therapies will be needed to optimize the current treatment strategy for T-LBL/ALL. The aim of this study was to analyse expression and significance of CD47, PD1 and PDL1 in. T-LBL/ALL. We performed immunohistochemistry staining and real time fluorescence quantitative PCR (qRT-PCR) on FFPE tissues. Immunohistochemistry results showed that the high expression rate of CD47 protein was 46.4% (26/56) and the positive expression rate of PDL1 protein was 37.5% (21/56). PD1 expression was observed in tumor infiltrating lymphocytes in approximately 20% of T-LBL/ALL patients, but not expressed on tumor cells of T-LBL/ALL. And the results of qRT-PCR showed that the relative expression levels of CD47, PDL1 and PD1 mRNA in 56 cases of T LBL/ALL were significantly higher than those in control group (6.915 vs 4.050, 12.255 vs 2.575, 37.990 vs 3.615), and the differences were all statistically significant (p all <0.05). Univariate analysis showed that age, CD47 protein, CD47 mRNA,PDL1 protein and PDL1 mRNA expression were closely correlated with prognosis (P all <0.05). We found that the overall one-year survival rates of patients with a high expression (≥M) of CD47 and PDL1 mRNA were higher than in patients with low expression (<M). However, the overall one-year survival rate of patients with a high expression (≥M) of CD47 and PDL1 protein were lower than in patients with low expression (<M). And patients with ≤25 years old had a worse prognosis than with >25 years old. Multivariate Cox regression analysis showed that the high expression of CD47 and PDL1 protein were independent prognostic factors (both p < 0.05). In a word, PD1/PDL1 and CD47 may be involved in the disease progression and prognosis of T-LBL/ALL, and detection and targeting of CD47 and PD1/PDL1 may provide a rational basis to for treatment of T-LBL/ALL.

Hide or defend, the two strategies of lymphoma immune evasion: potential implications for immunotherapy

Evading immune eradication is a prerequisite for neoplastic progression and one of the hallmarks of cancer. Here, we review the different immune escape strategies of lymphoma and classify them into two main mechanisms. First, lymphoma cells may “hide” to become invisible to the immune system. This can be achieved by losing or downregulating MHC and/or molecules involved in antigen presentation (including antigen processing machinery and adhesion molecules), thereby preventing their recognition by the immune system. Second, lymphoma cells may “defend” themselves to become resistant to immune eradication. This can be achieved in several ways: by becoming resistant to apoptosis, by expressing inhibitory ligands that deactivate immune cells and/or by inducing an immunosuppressive (humoral and cellular) microenvironment. These immune escape mechanisms may have therapeutic implications. Their identification may be used to guide “personalized immunotherapy” for lymphoma.

Beyond Chemotherapy: Checkpoint Inhibition and Cell-Based Therapy in Non-Hodgkin Lymphoma

Immune-based treatment strategies, such as checkpoint inhibition and chimeric antigen receptor (CAR) T cells, have started a new frontier for treatment in non-Hodgkin lymphoma (NHL). Checkpoint inhibition has been most successful in Hodgkin lymphoma, where higher expression of PD-L1 is correlated with better overall response rate. Combinations of checkpoint inhibition with various chemotherapy or biologics are in clinical trials, with initially promising results and manageable safety profiles. CAR T-cell therapies that target CD19 are a promising and attractive therapy for B-cell NHLs, with a product approved by the US Food and Drug Administration in 2017. Changes in the target, hinge, or costimulatory domain can dramatically alter the persistence and efficacy of the CAR T cells. The ZUMA trials from Kite used CD19-(CD28z) CAR T cells, whereas the TRANSCEND studies from Juno and the JULIET studies from Novartis used CD19-(4-1BBz) CARs. Despite the recent successes with CAR T-cell clinical trials, major concerns associated with this therapy include cytokine release syndrome, potential neurotoxicities, B-cell aplasia, loss of tumor antigen leading to relapse, and cost and accessibility of the treatment. Although first-generation CAR T-cell therapies have failed in solid malignancies, newer second- and third-generation CAR T cells that target antigens other than CD19 (such as mesothelin or B-cell maturation antigen) are being studied in clinical trials for treatment of lung cancer or multiple myeloma. Overall, immune-based treatment strategies have given oncologists and patients hope when there used to be none, as well as a new basket of tools yet to come with further research and development.