Immune responses against cancer are dominated by T cell exhaustion and dysfunction. Recent advances have underscored the critical role of early priming interactions in establishing T cell fates. In this review, we explore the importance of dendritic cell (DC) signals in specifying CD8 + T cell fates in cancer, drawing on insights from acute and chronic viral infection models. We highlight the role

Vaccination strategies against HIV-1 aim to elicit broadly neutralizing antibodies (bnAbs) using prime-boost regimens with HIV envelope (Env) immunogens. Epitope mapping has shown that early antibody responses are directed to easily accessible nonneutralizing epitopes on Env instead of bnAb epitopes. Autologously neutralizing antibody responses appear upon boosting, once immunodominant epitopes are

Thymic stromal lymphopoietin (TSLP) is a type I cytokine that promotes allergic responses and mediates type 2 immunity. A balance between effector T cells (T effs ), which drive the immune response, and regulatory T cells (T regs ), which suppress the response, is required for proper immune homeostasis. Here, we report that TSLP differentially acts on T effs versus T regs to balance type 2 immunity

Regulatory T cells (T regs ) accumulate in the visceral adipose tissue (VAT) to maintain systemic metabolic homeostasis but decline during obesity. Here, we explored the metabolic pathways controlling the homeostasis, composition, and function of VAT T regs under normal and high-fat diet feeding conditions. We found that cholesterol metabolism was specifically up-regulated in ST2 hi VAT T reg subsets

A cell engineering approach demonstrates that precise regulation of cell signaling can be achieved using both endogenous and synthetic ligands.

Patient-derived NMDAR mAbs combined with single-particle cryo-electron microscopy reveal multiple GluN1 epitopes and distinct functional effects.

Mechanistic understanding of the inhibitory immunoreceptor PD-1 is largely based on mouse models, but human and mouse PD-1 share only 59.6% amino acid identity. Here, we found that human PD-1 is more inhibitory than mouse PD-1, owing to stronger interactions with the ligands PD-L1 and PD-L2 and more efficient recruitment of the effector phosphatase Shp2. In a mouse melanoma model with adoptively transferred

The NLRP3 inflammasome plays a critical role in innate immunity and inflammatory diseases. NIMA-related kinase 7 (NEK7) is essential for inflammasome activation, and its interaction with NLRP3 is enhanced by K + efflux. However, the mechanism by which K + efflux promotes this interaction remains unknown. Here, we show that NEK7 is rapidly phosphorylated at threonine-190/191 by JNK1 downstream of K

Chronic low-grade inflammation observed in older adults, termed inflammaging, is a common feature underlying a multitude of aging-associated maladies including a decline in hematopoietic activity. However, whether suppression of inflammaging can preserve hematopoietic health span remains unclear, in part because of a lack of tools to measure inflammaging within hematopoietic stem cells (HSCs). Here

A NIAID-sponsored workshop was held in September 2024, where challenges to understanding common mechanisms in autoimmune disease were discussed as opportunities to advance research.

Although macrophages in the meningeal compartments of the central nervous system (CNS) have been comprehensively characterized under steady state, studying their contribution to physiological and pathological processes has been hindered by the lack of specific targeting tools in vivo. Recent findings have shown that the dural sinus and its adjacent lymphatic vessels act as a neuroimmune interface.

The increasing use of anti–programmed cell death 1 (PD-1) immune checkpoint blockade has led to the emergence of immune-related adverse events (irAEs), including dysfunction of the submandibular gland (SMG). In this study, we investigated the immunoregulatory mechanism contributing to the susceptibility of the SMG to irAEs. We found that the SMGs of PD-1–deficient mice and anti–programmed cell death

Antigen-presenting cells (APCs) are readily activated after phagocytosing infected or DNA-damaged cells but not normal apoptotic cells for reasons that are not well understood. Here, we demonstrate that after DNA damage events, cytosolic dsDNA species trigger intrinsic STING signaling and the production of key immunogenic proteins, including CCL5, which renders such cells capable of APC activation

The rapid proliferation of germinal center (GC) B cells requires metabolic reprogramming to meet energy demands, yet these metabolic processes are poorly understood. By integrating metabolomic and transcriptomic profiling of GC B cells, we identified that asparagine (Asn) metabolism was highly up-regulated and essential for B cell function. Asparagine synthetase (ASNS) was up-regulated after B cell

Mycobacterium tuberculosis ( M.tb ) is a bacterial pathogen that has evolved in humans, and its interactions with the host are complex and best studied in humans. Myriad immune pathways are involved in infection control, granuloma formation, and progression to tuberculosis (TB) disease. Inflammatory cells, such as macrophages, neutrophils, conventional and unconventional T cells, B cells, NK cells

T cell activity is governed by T cell receptor (TCR) signaling and constrained by immune checkpoint molecules, including programmed cell death protein 1 (PD-1), cytotoxic T lymphocyte–associated antigen 4 (CTLA-4), and lymphocyte activation gene 3 (LAG-3). The basis for how LAG-3 binds to human leukocyte antigen class II molecules (HLA-II) remains unknown. Here, we present the 3.4-angstrom crystal

Endoglycosidase CU43 removes IgG Fc glycans, inhibits IgG effector functions, and prevents pathology in multiple disease models.

The molecular mechanisms by which worm parasites evade host immunity are incompletely understood. In a mouse model of intestinal helminth infection using Heligmosomoides polygyrus bakeri ( Hpb ), we show that helminthic glutamate dehydrogenase (heGDH) drives parasite chronicity by suppressing macrophage-mediated host defense. Combining RNA-seq, ChIP-seq, and targeted lipidomics, we identify prostaglandin

Mucosal-associated invariant T (MAIT) cells are known for their rapid effector functions and antibacterial immune protection. Here, we define the plasticity of interferon-γ (IFN-γ)–producing MAIT1 and interleukin-17A (IL-17A)–producing MAIT17 cell subsets in vivo. Whereas T-bet + MAIT1 cells remained stable in all experimental settings, after adoptive transfer or acute Legionella or Francisella infection

Severity of COVID-19 is affected by multiple factors; however, it is not understood how the inflammatory milieu of the lung at the time of SARS-CoV-2 exposure affects the control of viral replication. Here, we demonstrate that immune events in the mouse lung closely preceding SARS-CoV-2 infection affect viral control and identify innate immune pathways that limit viral replication. Pulmonary inflammatory

Lymph node IL-2 microniches guide development of T H 2 cells through induction of Blimp-1 expression and an IL-10–positive feedback loop.

During persistent antigen stimulation, exhausted CD8 + T cells are continuously replenished by self-renewing stem-like T cells. However, how CD8 + T cells adapt to chronic stimulation remains unclear. Here, we show that persistent antigen stimulation primes chromatin for regulation by the redox-sensing KEAP1-NRF2 pathway. Loss of KEAP1 in T cells impaired control of chronic viral infection. T cell–intrinsic

Secondary lymphoid organs (SLOs) provide the confined microenvironment required for stromal cells to interact with immune cells to initiate adaptive immune responses resulting in B cell differentiation. Here, we studied three patients from two families with functional hyposplenism, absence of tonsils, and complete lymph node aplasia, leading to recurrent bacterial and viral infections. We identified

Adenosine-to-inosine (A-to-I) editing of double-stranded RNA (dsRNA) by ADAR1 is an essential modifier of the immunogenicity of cellular dsRNA. The role of MDA5 in sensing unedited cellular dsRNA and the downstream activation of type I interferon (IFN) signaling are well established. However, we have an incomplete understanding of pathways that modify the response to unedited dsRNA. We performed a

T cell immunoglobulin and mucin domain–containing protein 3 (TIM-3) is an immune checkpoint that has critical roles in immune exhaustion. However, little is known about the mechanisms that regulate TIM-3 surface expression and turnover. Here, we report that human TIM-3 is palmitoylated by the palmitoyltransferase DHHC9 at residue cysteine 296 (Cys 296 ). Palmitoylation stabilized TIM-3 by preventing

NK cells offer a promising alternative to T cell therapies in cancer. We evaluated IPH6501, a clinical-stage, tetraspecific NK cell engager (NKCE) armed with a non-alpha IL-2 variant (IL-2v), which targets CD20 and was developed for treating B cell non-Hodgkin lymphoma (B-NHL). CD20-NKCE-IL2v boosts NK cell proliferation and cytotoxicity, showing activity against a range of B-NHL cell lines, including

LRRK2 polymorphisms (G2019S/N2081D) that increase susceptibility to Parkinson’s disease and Crohn’s disease (CD) lead to LRRK2 kinase hyperactivity and suppress autophagy. This connection suggests that LRRK2 kinase inhibition, a therapeutic strategy being explored for Parkinson’s disease, may also benefit patients with CD. Paneth cell homeostasis is tightly regulated by autophagy, and their dysfunction

Endogenous retroviruses (ERVs), comprising a substantial portion of the vertebrate genome, are remnants of ancient genetic invaders. ERVs with near-intact coding potential reactivate in B cell–deficient mice. To study how B cells contribute to host anti-ERV immunity, we used an antigen-baiting strategy to enrich B cells reactive to ERV surface antigens. We identified ERV-reactive B-1 cells expressing

OX40L-CAR-Tregs show promise for treating autoimmunity and transplantation rejection.

Identity confusion has emerged in the field of monocyte research with the identification of monocyte-like “doppelgänger” populations that exhibit phenotypical traits of classical monocytes but seem to vary in their origin, function, or migration behavior.

In adults, liver-resident macrophages, or Kupffer cells (KCs), reside in the sinusoids and sterilize circulating blood by capturing rapidly flowing microbes. We developed quantitative intravital imaging of 1-day-old mice combined with transcriptomics, genetic manipulation, and in vivo infection assays to interrogate increased susceptibility of newborns to bloodstream infections. Whereas 1-day-old KCs

Conventional dendritic cells (cDCs) generate protective cytotoxic T lymphocyte (CTL) responses against extracellular pathogens and tumors. This is achieved through a process known as cross-presentation (XP), and, despite its biological importance, the mechanism(s) driving XP remains unclear. Here, we show that a cDC-specific pore-forming protein called apolipoprotein L 7C (APOL7C) is up-regulated in

TP53 mutation triggers IL-34 secretion by cancer stem cells, reprogramming macrophages to suppress T cells and promote tumor immune escape.

Gastrointestinal (GI) B cells and plasma cells (PCs) are critical to mucosal homeostasis and the host response to HIV-1 infection. Here, high-resolution mapping of human B cells and PCs sampled from the colon and ileum during both viremic and suppressed HIV-1 infection identified a reduction in germinal center (GC) B cells and follicular dendritic cells (FDCs) during HIV-1 viremia. Immunoglobulin A–positive

CD45 is a cell surface phosphatase that shapes the T cell receptor signaling threshold but does not have a known ligand. A family of adenovirus proteins, including E3/49K, exploits CD45 to evade immunity by binding to the extracellular domain of CD45, resulting in the suppression of T cell signaling. We determined the cryo-EM structure of this complex and found that the E3/49K protein is composed of

Interferon-γ (IFN-γ) is a potent cytokine critical for response to immunotherapy, yet conventional methods to systemically deliver this cytokine have been hindered by severe dose-limiting toxicities. Here, we engineered a strain of probiotic bacteria that home to tumors and locally release IFN-γ. A single intratumoral injection of these IFN-γ–producing bacteria was sufficient to drive systemic tumor

Environmental exposures increase the risk for severe lung disease, but specific drivers of persistent epithelial injury and immune dysfunction remain unclear. Here, we identify a feedback circuit triggered by chitin, a common component of airborne particles, that affects lung health after epithelial injury. In mice, epithelial damage disrupts lung chitinase activity, leading to environmental chitin

Multiple cancers, including colorectal cancer (CRC), are more frequent and often more aggressive in individuals with obesity. Here, we showed that macrophages accumulated within tumors of patients with obesity and CRC and in obese CRC mice and that they promoted accelerated tumor growth. These changes were initiated by oleic acid accumulation and subsequent tumor cell–derived acid production and were

Immune checkpoint inhibitors have substantial advanced tumor treatment, but their limited benefits and strong responses in only a subset of patients remain challenging. In this study, we explored the immunomodulatory function of contactin-4 (CNTN4). CNTN4 was highly expressed in tumor tissues, and expression impaired the antitumor function of T cells. CNTN4 bound to amyloid precursor protein (APP)

Rhesus cytomegalovirus (RhCMV) vectors elicit major histocompatibility complex (MHC)–E–restricted CD8 + T cells that stringently control simian immunodeficiency virus (SIV) in rhesus macaques. These responses require deletion of eight RhCMV chemokine-like open reading frames (ORFs) that are conserved in human cytomegalovirus (HCMV). To determine whether HCMV encodes additional, nonconserved inhibitors

Dendritic cells sense confinement in the environment to induce migration in the absence of typical inflammatory stimuli.

Patients with autoimmune disease have exhausted antigen-specific T cells that remain capable of B cell support.

Dendritic cells (DCs) are uniquely capable of transporting tumor antigens to tumor-draining lymph nodes (tdLNs) and interact with effector T cells in the tumor microenvironment (TME) itself, mediating both natural antitumor immunity and the response to checkpoint blockade immunotherapy. Using LIPSTIC (Labeling Immune Partnerships by SorTagging Intercellular Contacts)–based single-cell transcriptomics

X chromosome inactivation (XCI) balances X-linked gene dosage between sexes. Unstimulated T cells lack cytological enrichment of X-inactive specific transcript (Xist) RNA and heterochromatic modifications on the inactive X chromosome (Xi), which are involved in maintenance of XCI, and these modifications return to the Xi after stimulation. Here, we examined allele-specific gene expression and epigenomic

The interferon (IFN) response is vital for the effectiveness of immune checkpoint inhibition (ICI) therapy. Our previous research showed that KRAS (Kirsten rat sarcoma viral) mutation impairs the IFN response in colorectal cancer (CRC), with an unclear mechanism. Here, we demonstrate that KRAS accelerates double-stranded RNA (dsRNA) degradation, impairing dsRNA sensing and IFN response by down-regulating

Multiple sclerosis (MS) is an inflammatory neurological disease of the central nervous system with a subclinical phase preceding frank neuroinflammation. CD8 + T cells are abundant within MS lesions, but their potential role in disease pathology remains unclear. Using high-throughput single-cell RNA sequencing and single-cell T cell receptor analysis, we compared CD8 + T cell clones from the blood

The intestinal mucosal surface is directly exposed to daily fluctuations in food and microbes driven by 24-hour light and feeding cycles. Intestinal epithelial tuft cells are key sentinels that surveil the gut luminal environment, but how these cells are diurnally programmed remains unknown. Here, we show that histone deacetylase 3 (HDAC3) controls tuft cell specification and the diurnal rhythm of

Heat is a cardinal feature of inflammation, yet its impacts on immune cells remain uncertain. We show that moderate-grade fever temperatures (39°C) increased murine CD4 T cell metabolism, proliferation, and inflammatory effector activity while decreasing regulatory T cell suppressive capacity. However, heat-exposed T helper 1 (T H 1) cells selectively developed mitochondrial stress and DNA damage that

Prolonging exposure to subunit vaccines during the primary immune response enhances humoral immunity. Escalating-dose immunization (EDI), administering vaccines every other day in an increasing pattern over 2 weeks, is particularly effective but challenging to implement clinically. Here, using an HIV Env trimer/saponin adjuvant vaccine, we explored simplified EDI regimens and found that a two-shot

Cancers eventually kill hosts even when infiltrated by cancer-specific T cells. We examined whether cancer-specific T cell receptors of CD4 + T cells (CD4TCRs) from tumor-bearing hosts can be exploited for adoptive TCR therapy. We focused on CD4TCRs targeting an autochthonous mutant neoantigen that is only presented by stroma surrounding the MHC class II–negative cancer cells. The 11 most common tetramer-sorted

Immune checkpoint blockade (ICB) enhances T cell responses against cancer, leading to long-term survival in a fraction of patients. CD8 + T cell differentiation in response to chronic antigen stimulation is highly complex, and it remains unclear precisely which T cell differentiation states at which anatomic sites are critical for the response to ICB. We identified an intermediate-exhausted population

Multi-omic analysis deciphers the impact of cell-intrinsic and systemic metabolomes on dengue vaccination immunogenicity.

IL-10 autoantibodies are detected in two patients with severe inflammatory bowel disease.

Understanding the phenotypic and transcriptional signature of immunoglobulin E (IgE)–producing cells is fundamental to plasma cell (PC) biology and development of therapeutic interventions for allergy. Here, using a mouse model of intranasal house dust mite (HDM) exposure, we showed that short-lived IgE PCs emerge in lung draining lymph nodes (dLNs) during early exposure (<3 weeks) and long-lived IgE

Langerhans cells (LCs) are distinct among phagocytes, functioning both as embryo-derived, tissue-resident macrophages in skin innervation and repair and as migrating professional antigen-presenting cells, a function classically assigned to dendritic cells (DCs). Here, we demonstrate that both intrinsic and extrinsic factors imprint this dual identity. Using ablation of embryo-derived LCs in the murine

Mucosal-associated invariant T (MAIT) cells are unconventional T cells that recognize microbial riboflavin pathway metabolites presented by evolutionarily conserved MR1 molecules. We explored the human MAIT cell compartment across organ donor–matched blood, barrier, and lymphoid tissues. MAIT cell population size was donor dependent with distinct tissue compartmentalization patterns and adaptations: