A novel non-Hodgkin lymphoma murine model closer to the standard clinical scenario

Abstract

BackgroundNon-Hodgkin lymphomas (NHL) are the most frequent hemato-oncological malignancies. Despite recent major advances in treatment, a substantial proportion of patients relapses highlighting the need for new therapeutic modalities. Promissory results obtained in pre-clinical studies are usually not translated when moving into clinical trials. Pre-clinical studies are mainly conducted in animals with high tumor burden; instead patients undergo chemotherapy as first line of treatment and most likely are under remission when immunotherapies are applied. Thus, an animal model that more closely resembles patients’ conditions would be a valuable tool.MethodsBALB/c mice were injected subcutaneously with A20 lymphoma cells and after tumor development different doses of chemotherapy were assessed to find optimal conditions for minimal residual disease (MRD) establishment. Tumor growth and survival, as well as drugs side effects, were all evaluated. Complete lymphoma remission was monitored in vivo using positron emission tomography (PET), and the results were correlated with histology. Immunological status was assessed by splenocytes proliferation assays in NHL-complete remission mice and by analyzing tumor cell infiltrates and chemokines/cytokines gene expression in the tumor microenvironment of animals with residual lymphoma.ResultsTwo cycles of CHOP chemotherapy at days 25 and 35 post-tumor implantation induced complete remission for around 20 days. PET showed to be a suitable follow-up technique for MRD condition with 85.7 and 75% of sensibility and specificity respectively. Proliferative responses upon mitogen stimulation were similar in animals that received chemotherapy and wild type mice. Tumors from animals with residual lymphoma showed higher numbers of CD4+ and CD8+ and similar numbers of NK, neutrophils and Tregs infiltrating cells as compared with non-treated animals. Gene expression of several cytokines as well as an array of chemokines associated with migration of activated T cells to tumor sites was upregulated in the tumor microenvironment of animals that received chemotherapy treatment.ConclusionsWe established a NHL-B pre-clinical model using standard chemotherapy to achieve MRD in immunocompetent animals. The MRD condition is maintained for approximately 20 days providing a therapeutic window of time where new immunotherapies can be tested in conditions closer to the clinics.

Salmonella Immunotherapy Improves the Outcome of CHOP Chemotherapy in Non-Hodgkin Lymphoma-Bearing Mice

“…Lymphoma-bearing mice were treated with two cycles of CHOP (CHOPx2) chemotherapy, at days 25 and 35 post-tumor implantation (p.t.i. ), as previously described ( 32 ). Drug doses used for each chemotherapy cycle were: cyclophosphamide 100 mg/kg i.p., doxorubicin 6 mg/kg i.p., vincristine 0.1 mg/kg i.p., and dexamethasone 0.2 mg/kg i.p.…”

“…Chemotherapy side effects were monitored as before ( 32 ), by evaluating body weight changes (BWCs) and hematological toxicity before and after CHOP administration. Lymphocytes, monocytes, and neutrophils recovery post-CHOP were evaluated in an automated blood cell counter and in peripheral blood smears ( 32 ).…”

“…Therefore, we found it relevant to develop preclinical studies resembling the clinical trial scenario. We have recently described the feasibility of applying CHOP chemotherapy used in clinics to A20-bearing mice and demonstrated that, albeit its cytotoxic effect, CHOP chemotherapy promoted a pro-inflammatory tumor microenvironment and an immune response that resulted in an extended progression-free survival (PFS) ( 32 ). Here, we explore the feasibility and efficacy of Salmonella LVR01 in combination with CHOP chemotherapy to treat NHL-bearing mice.…”

CRISPR/Cas9-Mediated Foxp1 Silencing Restores Immune Surveillance in an Immunocompetent A20 Lymphoma Model

“…To experimentally test this hypothesis we have used CRISPR/Cas9 genome editing to deplete Foxp1 from an immune competent lymphoma model. We selected the aggressive murine A20 model of B-cell lymphoma, which mimics key aspects of human DLBCL and has previously been used to study the antilymphoma immune response and test therapeutic approaches in an immunocompetent host (11)(12)(13). Notably, ectopic expression of allogeneic MHC-II in A20 lymphoma cells has already been shown to enhance T-cell proliferation (14).…”

A Novel Cytological Model of B-Cell/Macrophage Biphenotypic Cell Hodgkin Lymphoma in Ganp-Transgenic Mice

“…Overall, we established a cytological model of HL while focusing on its biphenotypic characteristics of B cells/macrophages and GANP, a signaling molecule that may modulate dynamic transdifferentiation and reprogramming of B cells to macrophages. To the best of our knowledge, this is the first cytological model of HL, although some non-HL models have already been established [24]. Ig-ganp Tg mice may serve as a novel cytological model that may facilitate the study of cytopathological etiology and oncogenesis of HL.…”