Document Type
Article
Publication Title
Multimodal Reprogramming Of The Tumor Microenvironment By MMR And Dual Checkpoint Blockade In Hepatocellular Carcinoma Models
Abstract
Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide, thus, there is an urgent need to develop more effective therapeutic options for this dismal condition. Tumor-infiltrating lymphocytes (TILs) are associated with improved response to immune checkpoint blockade in HCC, but their low abundance in most cases limits their therapeutic efficacy. Here, we demonstrate, in mice, that low-dose intratumoral immunovirotherapy with the trivalent measles, mumps, and rubella vaccine (MMR) induces superior tumor-growth delay and extended host survival compared to individually administered vaccines for measles, mumps, or rubella viruses. Further, our results show that MMR therapy synergizes with PD-1 and CTLA-4 blockade to reprogram the tumor microenvironment, resulting in increased CD8+ TIL infiltration and reduced PD-1 expression on TILs, among other effects. These changes in the immunological landscape translated into greater survival and more durable tumor-specific and memory immune responses for hosts. Comprehensive toxicology analysis revealed no evidence of MMR-induced liver or kidney toxicity after intrahepatic administration. This work reinforces an unrecognized role of MMR plus ICB in reprogramming the immune landscape in HCC through multimodal immune activation, providing a strong rationale for further development of MMR-based therapies for HCC.
First Page
Introduction Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer and a leading cause of cancer-related death worldwide (1). In the US, its incidence is rising faster than any other cancer, accounting for more than 30,000 deaths annually, with nearly 800,000 deaths globally (2–4). This increasing burden is largely attributed to metabolic risk factors—HCC prevalence has tripled over the past 3 decades due to rising cases of nonalcoholic fatty liver disease, obesity, and type 2 diabetes (5, 6). Although systemic therapies have improved survival outcomes, durable clinical responses remain elusive. First-line combination therapies with immune checkpoint blockade (ICB), via anti-programmed death ligand 1 (PD-L1), together with anti-VEGF and antibodies for cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) have provided survival benefits in a subset of patients (5, 7–11), but response rates remain confined to less than 30% of cases, and median survival for patients with unresectable advanced HCC continues to be less than 2 years (5, 7–15). A defining feature of ICB efficacy is the extent of tumor-infiltrating lymphocytes (TILs) in the tumor microenvironment (TME), which correlates with therapeutic outcomes (16, 17). However, most HCC tumors have a scarcity of TILs, which severely limits the immunotherapeutic potential of ICB (18, 19). Furthermore, the TME in HCC is characterized by abnormal angiogenesis, chronic inflammation, and extracellular matrix remodeling, and these features sustain an immunosuppressive niche that fosters tumor progression, invasion, and metastasis (18, 20, 21). Immunosuppressive mechanisms within the TME are major obstacles to immune surveillance, necessitating therapeutic approaches that promote TIL infiltration while also targeting pathways that promote immune escape (3, 22). Strategies to overcome these immune barriers and immune evasion in HCC, therefore, are actively being pursued. Preclinical and clinical studies have demonstrated the efficacy of ICB with VEGF blockade in HCC (23, 24), paving the way to the US Food and Drug Administration’s approval of combination regimens with ICB that targets PD-L1 and VEGF signaling to remodel the tumor vasculature and enhance immune infiltration. Even with these advances, however, only a fraction of HCC patients derives long-term benefits from ICB, largely due to the immunosuppressive nature of the TME and the paucity of TILs. This reinforces the urgent need for novel immunotherapeutic strategies in HCC to increase immune infiltration and reprogram the TME to improve responses to ICB. Immunovirotherapy has emerged as a promising approach to circumvent immune exclusion and enhance antitumor immunity (25–29). Among immunovirotherapies, the live trivalent measles, mumps and rubella vaccine (MMR) not only has well-established protective benefits against its targeted infectious diseases but also has potential in oncology, particularly due to its ability to reprogram the TME, which remains largely unexplored (30–32). In a preclinical HCC model, we previously demonstrated that MMR immunovirotherapy elicits antitumor immunity by augmenting cytotoxic T lymphocyte (CTL) infiltration and extends survival (26). Furthermore, MMR has demonstrated efficacy in a mouse model of colorectal cancer, prolonging survival (26), which suggests that the vaccine may have broader immunotherapeutic potential beyond HCC. While these findings highlight MMR’s therapeutic promise, it remains unclear whether MMR-driven immunovirotherapy can synergize with ICB to induce durable tumor control and extend survival in preclinical HCC models. Addressing this question is essential to establishing MMR as a novel immunotherapeutic adjuvant capable of enhancing antitumor immunity and improving clinical outcomes. Here, we report that intratumoral MMR therapy in a mouse model of HCC not only suppressed tumor growth and extended survival but also synergized with anti-PD-1 and anti-CTLA-4 blockade to remodel the protumorigenic TME. This combination therapy enhanced CTL infiltration, reduced T-cell exhaustion, and reprogrammed immunosuppressive myeloid compartments, resulting in durable tumor-specific immunity memory in subcutaneous and orthotopic models. Importantly, we observed no clinically significant liver or renal toxicity after intrahepatic MMR administration in non-tumor-bearing mice. These findings reveal MMR’s unrecognized immunomodulatory role in enhancing ICB therapeutic efficacy by reprogramming the HCC immune microenvironment to promote multimodal immune activation. Ultimately, this promotes durable tumor control with a favorable safety profile. This study provides preclinical evidence supporting further investigation into MMR as a potential and widely accessible adjuvant to enhance ICB efficacy, with broader implications for cancer immunotherapy.
Last Page
Statistical analysis All values were expressed as the mean ± standard error of the mean, and the results were analyzed with one-way analysis of variance and t-test to compare group means. The Kaplan-Meier survival method was used to examine mouse survival. All tests were performed with statistical software in GraphPad Prism, version 8 (GraphPad Software). Statistical significance was defined as p <0.05.
DOI
https://doi.org/10.3389/fimmu.2025.1679665
Publication Date
10-9-2025
Recommended Citation
Tesfay, Mulu Z.; Cios, Aleksandra; Ferdous, Khandoker Usran; Shelton, Randal S.; Mustafa, Bahaa; Simoes, Camila C.; Gokden, Murat; Miousse, Isabelle R.; Krager, Kimberly J.; Boerma, Marjan; Urbaniak, Alicja; Kunthur, Anuradha; Obulareddy, Sri; Eichhorn, Joshua M.; Post, Steven R.; Chamcheu, Jean Christopher; Moaven, Omeed; Chabu, Chiswili Y.; Duda, Dan G.; Conti, Matteo; Nardo, Bruno; Govindarajan, Rang; Fernandez-Zapico, Martin E.; Roberts, Lewis R.; Borad, Mitesh J.; Cannon, Martin J.; Basnakian, Alexei G.; and Nagalo, Bolni M., "Multimodal Reprogramming Of The Tumor Microenvironment By MMR And Dual Checkpoint Blockade In Hepatocellular Carcinoma Models" (2025). Faculty Publications. 39.
https://digitalcommons.subr.edu/osp_facpubs/39