interferon

Overview

Interferons are a family of cytokines with central roles in innate and adaptive immunity, especially in antiviral defense, immune regulation, and tumor surveillance. They are commonly grouped into type I interferons, type II interferon, and type III interferons, with interferon-γ (IFN-γ) being the best-known type II member. Interferon signaling induces broad transcriptional programs that can enhance antigen presentation, activate cytotoxic lymphocytes and macrophages, and shape inflammatory responses through pathways such as JAK-STAT.

Clinically, interferons have long been studied as therapeutic agents and as biomarkers of immune activation or dysregulation. Their effects are context dependent: they can support host defense against viruses and intracellular pathogens, but excessive, prolonged, or misdirected interferon activity can also contribute to tissue inflammation, immune exhaustion, and pathological remodeling in diseases such as COVID-19, cancer, autoimmune disorders, and hemophagocytic syndromes. In recent biomedical research, interferon pathways are frequently examined alongside checkpoint inhibitor therapy, PD-1/PD-L1 blockade, STING1 activation, cGAS-STING pathway signaling, and cytokine-based immunomodulation.

Role in Recent Research

Recent studies have continued to position interferon, particularly IFN-γ and type I interferon responses, as a major determinant of immune efficacy and immune pathology across cancer, infection, and inflammatory disease.

In pediatric hemophagocytic lymphohistiocytosis (HLH), emapalumab was studied as a monoclonal antibody targeting interferon-γ, with ruxolitinib used as a JAK1/2 inhibitor in combination with conventional therapy. This reflects the therapeutic strategy of dampening excessive IFN-γ-driven inflammation in HLH. The study context indicates growing interest in combining IFN-γ blockade with broader cytokine-signaling inhibition.

In metastatic pancreatic cancer, PD-L1 immune checkpoint blockade was linked to immune evasion through epigenetic Tap1 silencing, which reduced interferon-γ-inducible class I MHC expression. This work highlights the importance of IFN-γ in maintaining antigen presentation and shows how tumor variants with defective IFN-γ responsiveness may be selected during immunotherapy. Related cancer studies also reported interferon-γ-dependent changes in melanoma cells, rapid activation of DNA damage response-associated kinases, and increased antitumor immune activity in settings where CD8+ T cells and tumor-infiltrating lymphocytes were engaged.

Several studies examined interferon as an immunostimulatory adjunct in cancer therapy. In recurrent glioblastoma, intratumoral Delta-24-RGD was evaluated together with subcutaneous interferon gamma to augment antitumor immunity. In another study, a Ge1MT/Mel hydrogel increased CD8+ T cells and elevated antitumor cytokines including interferon-γ in the tumor microenvironment, supporting postoperative recurrence and metastasis control. A separate AAV-based platform used an interferon-inducible promoter to spatially control cytokine expression in irradiated tumors, linking interferon signaling to radiotherapy-guided local and systemic antitumor immunity. Additional work found that antigen-activated dCAR T cells sustained high IFN-γ production, which induced immunogenic cell death and activated conventional dendritic cells, reinforcing the role of IFN-γ in antigen spreading and tumor eradication.

Interferon signaling was also implicated in tumor resistance and immune remodeling. Sustained tumor cell-derived IFN was reported to induce osteopontin expression in tumor-associated macrophages via STAT signaling, creating immunosuppressive niches enriched in regulatory T cells and cancer-associated fibroblasts and promoting PARP inhibitor resistance. In melanoma, IFN-γ-dependent tumor responses were associated with reactive tumor-infiltrating lymphocytes and DNA damage response signaling. In poorly immunogenic tumors, AXL kinase inhibition increased cGAMP levels, activated IFN responses, and enhanced T cell and NK cell infiltration, consistent with cGAS-STING-linked interferon induction as a sensitizing mechanism for chemoimmunotherapy.

In infectious disease, interferons remained a major focus in antiviral and antifungal immunity. A multi-omics study of severe COVID-19 reported interferon response heterogeneity and linked lipid metabolism to immune alterations, underscoring both the protective and dysregulated aspects of interferon biology in respiratory viral infection. In invasive mold infections, adjunctive immunomodulation with anti-PD-1 antibodies and interferon-γ was proposed to help restore antifungal immunity in severely ill patients. In chronic HBV infection, the limited functional cure rate with nucleos(t)ide analogues or interferons was noted, emphasizing the need for improved therapeutic strategies. Vaccine studies also connected interferon pathways to immune responsiveness: variability in the TLR3 type I interferon pathway predicted RNA vaccine responses, and BNT162b2 vaccination was associated with increased antigen-specific IL-2, interferon-γ, and IL-21 production compared with CoronaVac recipients.

Interferon was further linked to inflammatory and autoimmune contexts. In rheumatoid arthritis tissues, low insulin signaling and deficient histone acetylation amplified proinflammatory IFNγ and TNF expression in T cells. In psoriatic disease, apremilast reduced IL-17 and interferon-γ production while increasing IL-10. In glucocorticoid-treated macrophages, a C1Q+ phenotype was primed for IFNγ-dependent CXCL9 secretion, illustrating how interferon shapes chemokine output and immune cell recruitment. In severe pediatric acute respiratory distress syndrome, pulmonary CD8+ T cells displayed an interferon-driven cytotoxic profile with exhaustion and apoptosis genes, consistent with interferon-associated immunopathology.

Across these studies, interferon emerges as both a therapeutic target and a functional readout of immune activation. It is used to enhance antitumor immunity, restore antimicrobial defense, and assess vaccine or treatment responses, but it is also a driver of immune dysregulation when overactive or chronically engaged.

Key Publications

• NEWJul Emapalumab plus conventional therapy with or without ruxolitinib for pediatric hemophagocytic lymphohistiocytosis: a single center retrospective study. (Immunologic research, 2026, PMID 42397658): "Emapalumab is a monoclonal antibody targeting interferon-γ, while ruxolitinib is a JAK1/2 inhibitor, and their application in HLH treatment is gaining attention."
• NEWJun Treg cells promote immunotherapy-induced immune evasion by restraining CD4 T cell control of MHC-I-deficient metastatic pancreatic cancer. (Science immunology, 2026, PMID 42361199): "We demonstrate that programmed death-ligand 1 immune checkpoint blockade promoted immune evasion by epigenetic Tap1 (transporter associated with antigen processing 1) silencing, increasing selection of metastatic tumor variants with defective interferon-γ (IFN-γ)-inducible class I major histocompatibility complex (MHC-I) expression."
• May The proteomics and phosphoproteomics landscape of melanoma under T cell attack. (Cell reports. Medicine, 2026, PMID 42167233): "Our analyses resolve interferon-γ-dependent changes in melanoma cells, identify the cytotoxic and regulatory T cell molecule (CRTAM) as a selective marker of reactive TILs, and reveal rapid tumor-intrinsic activation of DNA damage response-associated kinases, exposing potential therapeutic vulnerabilities."
• May Emerging evidence for anti-PD-1 and IFN-γ as adjunctive immunotherapy in invasive mold infections. (mBio, 2026, PMID 42171361): "Adjunctive immunomodulation, including anti-PD-1 antibodies and interferon-γ, may help restore antifungal immunity in severely ill patients."
• Jun Interleukin-4 alleviate polycystic ovary syndrome through promoting the polarization of M2 type macrophages via targeting NF-κB/IκB pathway. (European journal of pharmacology, 2026, PMID 42119768): "...concomitantly enhancing interleukin-10 (IL-10) and interferon-γ (IFN-γ) expression, whilst suppressing M1 macrophage infiltration."
• May Systemic multi-omics analysis reveals interferon response heterogeneity and links lipid metabolism to immune alterations in severe COVID-19. (Genome medicine, 2026, PMID 42216049): "Interferons play a central role in antiviral defense, but their dysregulation contributes to inflammation and immune dysfunction in respiratory viral infections, including COVID-19."
• May Insulin enables acquisition of the IL7R+ memory phenotype in PD1+ T cells in RA tissues. (Cell death & disease, 2026, PMID 42185247): "Low insulin signaling and deficient histone acetylation in RA T cells amplified proinflammatory IFNγ and TNF expression."
• May Meloxicam-1-d-MT Dual-Drug Hydrogel Serves as an Immunomodulator to Reverse Tumor Postoperative Recurrence and Metastasis. (ACS applied materials & interfaces, 2026, PMID 42081317): "Importantly, the Ge1MT/Mel hydrogel markedly stimulates a potent antitumor immune response in the cancer lesion microenvironment, increasing antitumor immune cells including CD8+ T cells, as well as elevating antitumor cytokines such as interferon-γ."
• May Glucocorticoids induce a phagocytic C1Q+ macrophage phenotype primed for IFNγ-dependent CXCL9 secretion. (Scientific reports, 2026, PMID 42151378): "Upon IFNγ stimulation, secretion of the T cell chemoattractant CXCL9 was higher in C1Q+ macrophages than in classical pro-inflammatory M1 macrophages."
• May A high dimensionality approach reveals immunopathogenic responses driving severe pediatric acute respiratory distress syndrome. (Nature communications, 2026, PMID 42140972): "Pulmonary CD8 + T cells display an interferon-driven cytotoxic profile, with exhaustion and apoptosis genes;"