Antigen presentation requirements for effective cDC1-based cancer immunotherapy

Pineda, J. E.; Minowa, T.; Shen, L.; Zhou, Y.; Dyevoich, A. M.; Patel, B.; Schneider, S. M.; Keshari, S.; Saha, A.; Riba, M. N.; Wang, J.; Watowich, S. S.; Gubin, M. M.

doi:10.64898/2026.01.24.701412

bioRxiv · 10.64898/2026.01.24.701412

Antigen presentation requirements for effective cDC1-based cancer immunotherapy

Pineda, J. E.·Minowa, T.·Shen, L.·Zhou, Y.·Dyevoich, A. M.·Patel, B.·Schneider, S. M.·Keshari, S.·Saha, A.·Riba, M. N.·Wang, J.·Watowich, S. S.·Gubin, M. M.

View original source ↗Export metadata ↓

Abstract

Type 1 conventional dendritic cells (cDC1s) are important for generating and sustaining antitumor immunity. Accordingly, the abundance of cDC1s in human tumors correlates with improved outcomes in cancer. Capitalizing on this role, we previously demonstrated that vaccination with in vitro-derived murine cDC1s elicits durable tumor control in multiple preclinical models; however, the immunological mechanisms underlying the efficacy of cDC1 vaccination remain unclear. Here, we examined whether in vitro-derived cDC1s resemble tumor-infiltrating DC populations and whether MHC-I and MHC-II antigen presentation contribute to cDC1-mediated tumor control following vaccination in melanoma. As expected, MHC-I- or MHC-II-deficiency had minimal impact on the transcriptional state of cDC1s in homeostasis or following stimulation with the adjuvant poly dI:dC. Moreover, in vitro-derived cDC1s cultured under steady-state conditions closely resembled tumor-infiltrating cDC1s, whereas their poly dI:dC-stimulated counterparts resembled CCR7+ tumor-infiltrating DC populations, also referred to as mregDCs or LAMP3+ DCs. Our data further show that both MHC-I and MHC-II contribute to tumor control upon cDC1 vaccination, and coexpression of MHC-I and MHC-II on the same cDC1 is necessary for a robust vaccine response. We also identified an important function for host cDC1s in supporting the efficacy of vaccination with in vitro-derived cDC1s, as judged by impaired tumor control in Irf8+32-/- mice, which lack endogenous cDC1s. Overall, these results indicate that effective antitumor responses depend on MHC-I and MHC-II antigen presentation by vaccine-delivered cDC1s, with additional contributions from host cDC1s. Key pointsO_LIIn vitro-generated cDC1s resemble intratumoral DC populations found in mice and humans. C_LIO_LIMHC-I and MHC-II antigen presentation by vaccine-delivered cDC1s contribute to antitumor efficacy. C_LIO_LICoexpression of MHC-I and MHC-II on the same cDC1 enhances vaccine responses. C_LIO_LIAntitumor responses reflect the activity of vaccine and endogenous cDC1s. C_LI

Source connections

Published article ↗

Explore related subjects

immunology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Pineda, J. E., Minowa, T., Shen, L., Zhou, Y., Dyevoich, A. M., Patel, B., Schneider, S. M., Keshari, S., Saha, A., Riba, M. N., Wang, J., Watowich, S. S., Gubin, M. M.. 2026-01-26. Antigen presentation requirements for effective cDC1-based cancer immunotherapy. https://doi.org/10.64898/2026.01.24.701412

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

TFAM Dependent Mitochondrial Fitness Limits CD8⁺ T Cell Immunopathology and Sustains Protective Immunity during Viral Pneumonia

During respiratory virus infection, CD8 T cells kill infected cells and establish antigen-specific memory, but mechanisms regulating these functions remain incompletely understood. Here, we identify mitochondrial transcription factor A (TFAM)-dependent mitochondrial fitness as a regulator of CD8 T cell function during influenza infection. Human CD8 T cells exhibited an age-associated decline in TFAM expression and mitochondrial function. To model this physiologically relevant decline and determine its consequences for antiviral immunity, we generated CD8 T cell-specific TFAM-haploinsufficient mice. TFAM insufficiency disrupted mitochondrial integrity and bioenergetics and increased mitochondrial DNA and oxidative stress. During influenza infection, TFAM-insufficient CD8 T cells exhibited increased cytotoxic and inflammatory activity associated with lung immunopathology without improved viral control. This early phenotype was followed by loss of effector function, diminished antigen-specific responses, reduced protection following adoptive transfer, and impaired heterosubtypic recall immunity. Thus, TFAM-dependent mitochondrial fitness is a cell-intrinsic regulator that limits immunopathology while sustaining recall immunity.

immunology↗

bioRxiv2026

Gasdermin E couples mitochondrial stress to STING-driven neuronal pyroptosis during Chandipura virus encephalitis

Neurotropic RNA viruses are major causes of fatal encephalitis worldwide, yet how infected neurons transition from antiviral defense to inflammatory cell death is not well characterized. Chandipura virus (CHPV), an emerging neurotropic rhabdovirus, causes acute, rapidly progressive encephalitis with high case fatality in children, but the mechanisms underlying its neuropathogenesis remain poorly defined. Here, we demonstrate that CHPV suppresses canonical RNA virus sensing early but subsequently switches to a mitochondria-driven innate immune program that culminates in inflammatory cell death. Early infection of neuronal cells with CHPV was marked by reduced levels of the mitochondrial antiviral adaptor protein, MAVS and attenuation of type I and III interferon responses. As infection progressed, mitochondrial dysfunction promoted accumulation of mtROS, mitochondrial accumulation of cleaved GSDME and cytosolic mtDNA release, triggering STING activation, which coincided with robust neuroinflammation and pyroptotic cell death. Pharmacological inhibition or genetic silencing of STING markedly attenuated inflammatory signaling, prevented pyroptotic membrane rupture and protected neurons from cell death without significantly affecting viral replication. In contrast, GSDME depletion reduced both viral replication and neuronal death. Notably, GSDME depletion markedly attenuated STING phosphorylation, while STING depletion also reduced GSDME activation, revealing functional coupling between these pathways during CHPV-induced neuronal injury. Collectively, our findings identify a mitochondria-GSDME-STING axis linking early immune evasion to neuroinflammation during CHPV infection, revealing a previously unrecognized mechanism of inflammatory neuronal death in viral encephalitis and highlighting STING as a potential therapeutic target in certain CNS viral infections.

immunology↗

bioRxiv2026

Mutanome-guided immunopeptidomics of blood plasma for neoepitope detection in solid tumors is constrained by cfDNA variant calling sensitivity and MS detection limits

Introduction: Neoepitopes form the basis of tumor-specific immune responses. Tissue biopsy, the primary source for neoepitope detection, is limited and invasive. Therefore, we aimed to identify neoepitopes by mutanome-guided immunopeptidomics from plasma of cancer patients. Methods: Mass spectrometry (MS) data analysis of HLA ligands from plasma (n = 4) was guided by patient-specific mutanomes of cell-free DNA (cfDNA) from plasma or tumor genomic DNA (tgDNA) from tissue. Matched tumor tissue and healthy donor plasma served as controls. Neoepitopes were validated with synthetic peptides, and immunogenicity was assessed using IFN-gamma ELISpot and intracellular cytokine staining. Results: Wild-type immunopeptidomes from tissue and plasma overlapped by 58%, with 91% of plasma HLA ligands rediscovered in tissue. 13 out of 15 tumor-associated HLA ligands detected in plasma were rediscovered in the matching tissue. However, no neoepitopes in plasma were identified by immunopeptidomics guided by cfDNA mutanomes, likely reflecting the limited overlap between cfDNA and tgDNA mutanomes (15%). Using the tgDNA mutanome as a complementary reference, two neoepitopes were detected in one patient's plasma, albeit at the MS detection limit. Both neoepitopes were also discovered in tissue, along with three tissue-exclusive neoepitopes. Two tissue-exclusive neoepitopes induced antigen-specific T cell responses in healthy donor PBMCs. Conclusion: In summary, plasma immunopeptidomics enables profiling of HLA ligands from wild-type proteins, including TAAs. In principle, neoepitope detection from plasma at the peptide level is feasible, but tissue remains the gold standard for variant calling and neoepitope identification. Improved detection methods may enable minimally invasive approaches in the future.

immunology↗