Journal of Experimental Medicine最新文献

Patients with loss-of-function DOCK8 or dominant-negative STAT3 variants have hyper-IgE syndrome, although only DOCK8 deficiency consistently presents with elevated food-specific IgE and symptomatic allergy. We previously found in mice that DOCK8 restricts the differentiation of IL-13+ T follicular helper (Tfh13) cells that drive anaphylactic IgE, although the mechanisms were unclear. Here, we show that DOCK8 promotes STAT3 activity, which inhibits GATA3 in T cells. However, only patients with DOCK8, but not STAT3, deficiency had elevated Tfh13 cells. Cell-specific deletion of either Dock8 (T-Dock8-/-) or Stat3 (T-Stat3-/-) augmented peanut-specific IgE and Tfh13s when oral sensitization was promoted by adjuvants. However, the phenotypes diverged during adjuvant-free oral peanut exposure: only T-Dock8-/- mice developed Tfh13 cells and peanut-specific IgE, accompanied by reduced Foxp3+ Tregs. Treg depletion in T-Stat3-/- mice unmasked Tfh13 induction to oral antigen alone. Thus, DOCK8 and STAT3 cooperate to restrain Tfh13 differentiation to food allergens, and additional Treg impairment in DOCK8 deficiency allows for Tfh13 cell induction and allergy.

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype with the highest rates of recurrence, metastasis, and patient mortality due to the absence of effective therapies. Hypoxia-inducible factor 1 (HIF-1) regulates the expression of thousands of RNAs in TNBC. Here, we demonstrate that transcription of the ISG20 gene, which encodes an RNA exonuclease, is activated by HIF-1 in TNBC cells. ISG20-mediated degradation of RHOBTB3 mRNA increases HIF-1α protein expression and activates NANOG signaling, which increases breast cancer stem cell specification and lung metastasis. ISG20 also degrades STAT1 and IRF1 mRNAs, leading to decreased expression of CXCL10 and impaired recruitment of CD8+ T cells and natural killer cells, thereby promoting breast cancer immune evasion. Silencing ISG20 increases the sensitivity of mouse TNBC cells to anti-PD1 antibody immune checkpoint blockade. Our data suggest that targeting ISG20, in combination with immunotherapy, could be an effective therapeutic strategy for TNBC.

Fulminant viral hepatitis (FVH) is a devastating condition caused by hepatotropic viruses such as hepatitis A virus (HAV), hepatitis B virus (HBV), and HSV-1/2. We studied 149 FVH patients (73 males and 76 females, aged 1-76) for blood autoantibodies (auto-Abs) neutralizing type I interferons (IFNs; IFN-α2, -β, -ω). Six of 16 (37.5%) HSV-triggered FVH patients carried such auto-Abs on admission, including three with a previously known autoimmune disease. These patients contrasted with 133 HAV- (n = 46) or HBV-triggered (n = 87) patients, none of whom had such detectable auto-Abs. Odds ratios for HSV-triggered FVH in individuals with auto-Abs ranged from 35.3 (95% CI: 13.0-96.2; P < 10-7) for those neutralizing only 100 pg/ml IFN-α/ω to 1,895 (CI: 448.5-8,002; P < 10-12) for those neutralizing both IFN-α and IFN-ω at 10 ng/ml. Over one third of HSV-triggered FVH cases in this international cohort were due to preexisting auto-Abs. This finding highlights auto-Abs against type I IFNs as a major determinant of HSV-FVH and paves the way for targeted preventive or therapeutic interventions.

Avian influenza A virus (IAV) H5N1 is an emerging threat of human pandemic. We describe a 71-year-old man who died of H5N1 pneumonia in Louisiana and whose blood contained autoantibodies neutralizing type I IFNs (AAN-I-IFNs), including the 12 IFN-α subtypes (1-10 ng/ml) and IFN-ω (100 pg/ml). Causality between these AAN-I-IFN and lethal outcome of avian influenza in this patient is based on (1) our previous report that AA-I-IFN underlie about 5% of cases of critical pneumonia triggered by seasonal influenza viruses in three cohorts, (2) the rarity of this combination of AAN-I-FNs in individuals over 70 years old (<1%), and (3) the rarity of lethal avian influenza among infected individuals (<1%). AAN-I-IFNs underlie a growing number of severe viral diseases, from arboviral encephalitis to viral pneumonia, particularly in the elderly. This case suggests they can also underlie life-threatening avian H5N1 influenza. The presence of AAN-I-IFN may facilitate infection, replication, and adaptation of zoonotic IAVs to humans and, therefore, human-to-human transmission.

Antiretroviral therapy suppresses HIV-1 infection but fails to eliminate a reservoir of intact latent proviruses that reside primarily in CD4+ T cells. The lack of precise understanding of the latent compartment has made it challenging to develop curative strategies for HIV-1 infection. Here we report on the properties of CD4+ T cell clones carrying intact latent proviruses, expanded in vitro from single cells obtained from the reservoir of people living with HIV-1. The latent proviruses in the clones were integrated into ZNF genes, nongenic satellite, and centromeric regions, frequently associated with latency. Despite their descent from single cells, only a fraction of the cells (0.4-14%) expressed relatively low levels of HIV-1 that did not measurably alter host gene transcriptome. Latency-reversing agents (LRAs) variably increased expression, but the effects were modest and clone and LRA specific. The results suggest that pharmacologic and immunologic approaches to clear the reservoir should be optimized to accommodate intra- and inter-clonal diversity.

Modeling complex (patho)physiological processes by sequential targeted mutagenesis in mice is limited by the lack of precision of cellular targeting and complex breeding strategies. We present a new Cre/DreERT2 dual-recombinase germinal center B cell (GCBC)-specific strain, with co-expression of the recombinases from a single allele. This enables highly efficient Cre-mediated FOXO1 knockout in GCBCs in vivo, followed by time-controlled, efficient Dre-mediated FOXO1 re-expression in the same cells, leading to functional rescue of GC compartmentalization and class switch recombination. The present approach can be easily adapted to other cellular contexts.

Immune responses to pathogens lead to the generation of plasma cells through a complex interplay of B cells with their microenvironment in lymphoid organs. To identify new regulators of B cell activation and plasmablast differentiation in the context of the splenic microenvironment, we established an in vivo system for pooled sgRNA CRISPR/Cas9 screens in immunized mice. To improve the infection efficiency of naïve B cells, we generated Cd23-Cre Rosa26LSL-EcoR/+ mice exhibiting increased expression of the ecotropic lentivirus receptor EcoR on naïve B cells. Upon adoptive B cell transfer and immunization of recipient mice, 379 sgRNAs, targeting genes with high expression in plasma cells, were analyzed for their effects on plasmablast generation. Gene hits, encoding 23 positive and 18 negative regulators of B cell activation, plasmablast differentiation, or homeostasis, were uniquely identified in these in vivo screens. Validated genes encoded proteins involved in cell adhesion, signal transduction, protein folding, iron transport, and enzymatic processes. Hence, our in vivo screening system identified novel regulators controlling B cell-mediated immune responses.

Mucosal-associated invariant T (MAIT) cells are predominantly located in barrier tissues where they rapidly respond to pathogens and commensals by recognizing microbial derivatives of riboflavin synthesis. Early-life exposure to these metabolites imprints the abundance of MAIT cells within tissues, so we hypothesized that antibiotic use during this period may abrogate their development. We identified antibiotics that deplete riboflavin-synthesizing commensals and revealed an early period of susceptibility during which antibiotic administration impaired MAIT cell development. The reduction in MAIT cell abundance rendered mice more susceptible to pneumonia, while MAIT cell-deficient mice were unaffected by early-life antibiotics. Concomitant administration of a riboflavin-synthesizing commensal during antibiotic treatment was sufficient to restore MAIT cell development and immunity. Our work demonstrates that transient depletion of riboflavin-synthesizing commensals in early life can adversely affect responses to subsequent infections.

Mapping the causal circuits that shape the phenotypic and functional landscape of immune cells remains a formidable challenge. Recent advances in pooled CRISPR-based screens, coupled with multiplexed single-cell profiling and imaging-based spatial readouts, make this goal increasingly attainable. In this Perspective, we discuss how CRISPR-based genetic screens will fundamentally transform our understanding of immunobiology. We highlight the applications of state-of-the-art, high-throughput pooled perturbation approaches, including emerging methodologies for bulk, single-cell, and spatial CRISPR screens, to advance our understanding of immunity and in vivo biology. Additionally, we summarize new strategies to address the complexity of combinatorial perturbations to uncover genetic interactions and mechanistic drivers of immunity at unprecedented scale and resolution. By integrating CRISPR screening data with experimental insights, we advocate a new framework in immunology research that leverages perturbation-driven regulatory effects and networks to discover new therapeutic targets and establish causal systems biology and immunology for advancing immunological knowledge and therapeutic application.