Inducible bronchus associated lymphoid tissue (iBALT) is a tertiary lymphoid structure (TLOs) that resembles secondary lymphoid organs (SLOs). iBALT is induced in the lung in response to antigen ...exposure. In some cases, such as infection with
Mycobacterium tuberculosis (Mtb)
, the formation of iBALT structure is indicative of an effective, protective immune response. However, with persistent exposure to antigen during chronic inflammation, allergy, or autoimmune diseases, iBALT may be associated with exacerbation of inflammation. iBALT is characterized by well-organized T and B areas enmeshed with conventional dendritic cells (cDCs), follicular dendritic cells (FDCs) and stromal cells, usually located surrounding airways or blood vessels. Several of the molecular signals and cellular contributors that mediate formation of iBALT structures have been recently identified. This review will outline the recent findings associated with the formation and maintenance of iBALT, and their contributions toward a protective or pathogenic function in pulmonary disease outcome.
Abstract
NK cells exhibit memory properties after activation with haptens, viral infection, or cytokines with each stimulus having distinct biology. Memory-like (ML) NK cells differentiate over one ...week after brief activation with combined IL-12/15/18, and have augmented responses upon restimulation by cytokines, activating receptor, or tumor targets. While much is known about their functional characteristics, there are large gaps in our understanding of the molecular mechanisms involved in programming conventional (c)NK cells into ML NK cells. As ML NK cells have enhanced ability to produce IFN-γ after multiple cell divisions, this suggests that the IFNG gene, and others, may be epigenetically poised. Therefore, we hypothesize that activation with IL-12/15/18 triggers epigenetic remodeling of cNK cells to ML NK cells that drives enhanced functionality. To test this, we performed ATAC-seq on baseline cNK cells, IL-12/15/18 activated NK cells, and in vitro differentiated cNK and ML NK cells after one week. Activation with IL-12/15/18 induces dramatic early epigenetic remodeling with >10,000 differentially accessible regions (DARs) compared to cNK cells. Moreover, ML differentiation generates epigenetically distinct ML NK cells (>1,000 DARs) compared to in vitro differentiated cNK cells, including increased IFNG locus accessibility, suggesting epigenetic mechanisms regulate their enhanced functionality. Also, ML NK cells are markedly different from IL-12/15/18 activated NK cells (>15,000 DARs) suggesting not all epigenetic changes are immediately induced, and time is required for full implementation of the memory-like state. Together, this supports that ML NK cells rely on epigenetic programming for enhanced function.
Supported by grants from NIH (P50CA171963, R01CA205239, P30CA91842, 1F31GM146361-01).
Abstract
NK cells are cytotoxic innate lymphoid cells that can differentiate into memory-like (ML) NK cells following IL-12/15/18 stimulation. Previous work identified that CD8α expression on donor ...ML NK cells was negatively associated with outcome for cellular therapy of AML. However, the role of CD8α on human NK cells remains poorly studied, and murine NK cells are CD8α-precluding study in mice. We found that CD8α-NK cells had greater proliferation and survival in vitro and in vivo. Interestingly, we observed that CD8α expression was dynamic, and a subset of CD8α-NK cells upregulated CD8α (“new” CD8+) after IL-15 stimulation. Notably, the “new” CD8+ NK cells were the most proliferative in vitro and in vivo, and had significantly greater signaling following IL-15 stimulation. Strikingly, we also found that “new” CD8+ NK cells had significantly higher glucose uptake, nutrient receptor expression, and an enhanced capacity for glycolysis and oxidative phosphorylation. These results indicate that recent CD8α acquisition marks the ability of NK cells to respond to IL-15 signals to engage in the robust metabolic activity required for proliferation. We also investigated the role of CD8α in NK cell activation, given that CD8α can bind HLA and associate with Lck. In the absence of CD8α, NK responses (CD107a, IFNg, TNF) following activating receptor ligation were enhanced for several receptors, suggesting an intrinsic role for CD8α in inhibiting NK cell activation. Together, these results identify a novel association of CD8α with treatment outcome for NK cellular therapy and identify a previously unappreciated role of CD8α on human NK cell proliferation, metabolism, and response through activating receptors.
Supported by grants from NIAID F30AI16131
Effort thrombosis or Paget-Schroetter syndrome most often affects young, active adults who are engaged in sports activities or whose professions require repetitive arm movements causing trauma to the ...axillary-subclavian vein and precipitating deep vein thrombosis. The presence of unilateral edema in the upper extremity is often thought to be attributable to trauma from an exercise regimen rather than acute deep vein thrombosis or compression of the subclavian vein by extrinsic anatomic structures. Because this syndrome occurs in young, active adults it has the potential for considerable long-term morbidity if it remains undetected or inadequately treated. Inadequate or inappropriate treatment may cause a loss of productivity over a lifetime and significantly affect the quality of life. Although more prevalent in male athletes, it is now increasingly affecting young women as they become more seriously involved in athletic endeavors. The purpose of this article is to increase the awareness of the prevalence, clinical significance, and importance of early detection of effort thrombosis of the axillary-subclavian vein, also known as Paget Schroetter syndrome, to educate health care providers regarding the limitations of some diagnostic tools, and to introduce new methods of treatment that offer better long-term results. The prevalence, differential diagnosis, diagnostic modalities, and medical and surgical interventions that have been successfully used to treat Paget-Schroetter syndrome are discussed, and evidence is provided to support the selections. The results of patients who were identified and treated within the last 2 years at the University of Southern California Center for Vascular Care are reviewed.
Abstract
IL-12/15/18 activation induces natural killer (NK) cell differentiation into cytokine-induced memory-like (ML) NK cells with enhanced IFNγ and killing of tumor targets that is antigen ...independent, rendering them distinct from conventional (cNK) and CMV-induced adaptive NK cells. In leukemia patients, ML NK cells have an excellent safety profile and 47% CR rate (PMID: 32826231). Despite their clinical promise, little is known about the biology underlying ML NK cells. Based on individual variability of human ML NK cell function, we hypothesized that ML NK cells manifest molecular heterogeneity. To this end, we applied Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) to profile RNA and protein expression on the single-cell level, and evaluated NK cell function.
Overnight IL-12/15/18 stimulation induced broad activation with distinct transcriptional programs evident in CD56 brightcompared to CD56 dimNK cells. In contrast, following in vitrodifferentiation for 7 days, IL-12/15/18 activated NK cells acquired a unique transcriptional and protein signature, and manifest one of two ML NK cell states (ML-1, ML-2), or remained similar to cNK cells. ML-1 was marked by increased activating receptor expression (NKp46, NKp30, NKp44) while ML-2 had increased expression of inhibitory receptors, CD25, HLA-DR, MKI67, and IFNG. In functional assays, ML-2 cells produced more IFNγ following cytokine stimulation than ML-1 cells. Further, ML-1 and ML-2 had divergent transcription factor profiles suggesting distinct mechanisms of regulation. Collectively, our findings reveal molecular and functional heterogeneity of ML NK cells, and investigations into ML subsets in patients receiving ML NK cell therapy are ongoing.
AAI Intersect Fellowship for Computational Scientists & Immunologists (JAF, TAF, AAP), T32GM139799 (JAF), P50CA171963 (TAF, MMB-E), R01CA205239 (TAF), P30CA91842 (TAF)
Since the T-box transcription factors (TFs) T-BET and EOMES are necessary for initiation of NK cell development, their ongoing requirement for mature NK cell homeostasis, function, and molecular ...programming remains unclear. To address this, T-BET and EOMES were deleted in unexpanded primary human NK cells using CRISPR/Cas9. Deleting these TFs compromised in vivo antitumor response of human NK cells. Mechanistically, T-BET and EOMES were required for normal NK cell proliferation and persistence in vivo. NK cells lacking T-BET and EOMES also exhibited defective responses to cytokine stimulation. Singlecell RNA-Seq revealed a specific T-box transcriptional program in human NK cells, which was rapidly lost following T-BET and EOMES deletion. Further, T-BET- and EOMES-deleted CD56.sup.bright NK cells acquired an innate lymphoid cell precursor-like (ILCP-like) profile with increased expression of the ILC-3-associated TFs RORCand AHR, revealing a role for T-box TFs in maintaining mature NK cell phenotypes and an unexpected role of suppressing alternative ILC lineages. Our study reveals the critical importance of sustained EOMES and T-BET expression to orchestrate mature NK cell function and identity.
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