Up-front autologous hematopoietic stem cell transplantation after first complete remission improved prognosis of advanced extra-nodal NKT cell lymphoma: A multicenter real-world study in China.

OBJECTIVES: The advanced extra-nodal NK/T-cell lymphoma (ENKTL) is highly aggressive and lacks effective treatment with a poor prognosis. This study aimed to investigate the effectiveness and safety of autologous hematopoietic stem cell transplantation (ASCT) in CR1. METHODS: Forty of 121 patients with advanced ENKTL from four Chinese hospitals between January 2006 to December 2021 who achieved first complete remission (CR1) and received at least 4 cycles chemotherapy, were enrolled for analysis. Twenty patients received ASCT as up-front consolidation therapy (Group A), and 20 patients only received chemotherapy (Group B). Clinical features, treatment and follow-up information were collected. RESULTS: With a median follow-up of 27 months (range, 4-188 months), the 2-year overall survival (OS) in Group A, 61% (95% CI 37%-85%), was better than that in Group B, 26% (95% CI 2%-50%), p = .018. The 2-year progression-free survival (PFS) was 56% (95% CI 32%-80%) in Group A, 26% (95% CI 2%-50%) in Group B, p = .026. III-IV grade hematological toxicity was the most common adverse event. No treatment-related deaths were observed in both groups. CONCLUSION: Up-front ASCT could improve survival of advanced ENKTL patients in first complete remission, but need be confirmed by a prospective clinical trial.

The biology of VSIG4: Implications for the treatment of immune-mediated inflammatory diseases and cancer.

V-set and immunoglobulin domain containing 4 (VSIG4), a type I transmembrane receptor exclusively expressed in a subset of tissue-resident macrophages, plays a pivotal role in clearing C3-opsonized pathogens and their byproducts from the circulation. VSIG4 maintains immune homeostasis by suppressing the activation of complement pathways or T cells and inducing regulatory T-cell differentiation, thereby inhibiting the development of immune-mediated inflammatory diseases but enhancing cancer progression. Consequently, VSIG4 exhibits a potential therapeutic effect for immune-mediated inflammatory diseases, but also is regarded as a novel target of immune checkpoint inhibition in cancer therapy. Recently, soluble VSIG4, the extracellular domain of VSIG4, shed from the surface of macrophages, has been found to be a biomarker to define macrophage activation-related diseases. This review mainly summarizes recent new findings of VSIG4 in macrophage phagocytosis and immune homeostasis, and discusses its potential diagnostic and therapeutic usage in infection, inflammation, and cancer.

[Transcriptional Modification and Potential Intracellular Signaling Mechanisms in Human Macrophages Primed by Interferon-γ].

OBJECTIVE: To explore the transcriptional gene expression profile up-regulated in human macrophages stimulated by interferon-γ (IFN-γ) and the underlying intracellular signaling mechanisms. METHODS: RNA-seq was used to sequence and compare the differential gene expression profiles of human macrophage cell line U937 before and after IFN-γ stimulation, and the significantly up-regulated genes were screened out, which were verified by fluorescence-based real-time quantitative polymerase chain reaction (qPCR) in U937 and THP1 cell lines, respectively. JAK/STAT, MAPK/ERK and PI3K/AKT pathway inhibitors were added to simultaneously to the cultured U937 cells upon IFN-γ priming to detect their effects on the expressions of the up-regulated genes to explore the key regulatory mechanisms. RESULTS: RNA-seq and qPCR results showed that, the well-recognized chemokines CXCL9, CXCL10 and CXCL11, the APOL family including APOL1, APOL2, APOL3, APOL4, APOL6 and GBP family GBP1, GBP2, GBP3, GBP4 and GBP5 as well were significantly up-regulated in IFN-γ-stimulated U937 cells. JAK/STAT3 pathway inhibitor inhibited the upregulation of APOL1, APOL4, GBP1, GBP4 and GBP5 genes induced by IFN-γ, while MAPK/ERK pathway inhibitor inhibited the upregulation of CXCL10 gene. PI3K/AKT pathway inhibitor inhibited the upregulation of APOL1,APOL4, APOL6, GBP1 and GBP5 genes induced by IFN-γ, all three signal pathway inhibitors could inhibit the upregulation of CXCL9 gene, and none of them could inhibit the upregulation of APOL3 gene. CONCLUSION: Upon IFN-γ stimulation, some family molecules of APOL and GBP in macrophages are significantly up-regulated, and PI3K/AKT, JAK/STAT3 and MAPK/ERK pathways have positive regulation on their expressions, respectively.

Complement C3a receptor inactivation attenuates retinal degeneration induced by oxidative damage.

Retinal degeneration causes vision loss and threatens the health of elderly individuals worldwide. Evidence indicates that the activation of the complement system is associated with retinal degeneration. However, the mechanism of complement signaling in retinal degeneration needs to be further studied. In this study, we show that the expression of C3 and C3a receptor (C3ar1) is positively associated with the inflammatory response and retinal degeneration. Genetic deletion of C3 and pharmacological inhibition of C3ar1 resulted in the alleviation of neuroinflammation, prevention of photoreceptor cell apoptosis and restoration of visual function. RNA sequencing (RNA-seq) identified a C3ar1-dependent network shown to regulate microglial activation and astrocyte gliosis formation. Mechanistically, we found that STAT3 functioned downstream of the C3-C3ar1 pathway and that the C3ar1-STAT3 pathway functionally mediated the immune response and photoreceptor cell degeneration in response to oxidative stress. These findings reveal an important role of C3ar1 in oxidative-induced retinal degeneration and suggest that intervention of the C3ar1 pathway may alleviate retinal degeneration.

SRSF1 Deficiency Impairs the Late Thymocyte Maturation and the CD8 Single-Positive Lineage Fate Decision.

The underlying mechanisms of thymocyte development and lineage determination remain incompletely understood, and the emerging evidences demonstrated that RNA binding proteins (RBPs) are deeply involved in governing T cell fate in thymus. Serine/arginine-rich splicing factor 1 (SRSF1), as a classical splicing factor, is a pivotal RBP for gene expression in various biological processes. Our recent study demonstrated that SRSF1 plays essential roles in the development of late thymocytes by modulating the T cell regulatory gene networks post-transcriptionally, which are critical in response to type I interferon signaling for supporting thymocyte maturation. Here, we report SRSF1 also contributes to the determination of the CD8+ T cell fate. By specific ablation of SRSF1 in CD4+CD8+ double positive (DP) thymocytes, we found that SRSF1 deficiency impaired the maturation of late thymocytes and diminished the output of both CD4+ and CD8+ single positive T cells. Interestingly, the ratio of mature CD4+ to CD8+ cells was notably altered and more severe defects were exhibited in CD8+ lineage than those in CD4+ lineage, reflecting the specific function of SRSF1 in CD8+ T cell fate decision. Mechanistically, SRSF1-deficient cells downregulate their expression of Runx3, which is a crucial transcriptional regulator in sustaining CD8+ single positive (SP) thymocyte development and lineage choice. Moreover, forced expression of Runx3 partially rectified the defects in SRSF1-deficient CD8+ thymocyte maturation. Thus, our data uncovered the previous unknown role of SRSF1 in establishment of CD8+ cell identity.

Tcf1 Sustains the Expression of Multiple Regulators in Promoting Early Natural Killer Cell Development.

T cell factor 1 (Tcf1) is known as a critical mediator for natural killer (NK) cell development and terminal maturation. However, its essential targets and precise mechanisms involved in early NK progenitors (NKP) are not well clarified. To investigate the role of Tcf1 in NK cells at distinct developmental phases, we employed three kinds of genetic mouse models, namely, Tcf7fl/flVavCre/+, Tcf7fl/flCD122Cre/+ and Tcf7fl/flNcr1Cre/+ mice, respectively. Similar to Tcf1 germline knockout mice, we found notably diminished cell number and defective development in BM NK cells from all strains. In contrast, Tcf7fl/flNcr1Cre/+ mice exhibited modest defects in splenic NK cells compared with those in the other two strains. By analyzing the published ATAC-seq and ChIP-seq data, we found that Tcf1 directly targeted 110 NK cell-related genes which displayed differential accessibility in the absence of Tcf1. Along with this clue, we further confirmed that a series of essential regulators were expressed aberrantly in distinct BM NK subsets with conditional ablating Tcf1 at NKP stage. Eomes, Ets1, Gata3, Ikzf1, Ikzf2, Nfil3, Runx3, Sh2d1a, Slamf6, Tbx21, Tox, and Zeb2 were downregulated, whereas Spi1 and Gzmb were upregulated in distinct NK subsets due to Tcf1 deficiency. The dysregulation of these genes jointly caused severe defects in NK cells lacking Tcf1. Thus, our study identified essential targets of Tcf1 in NK cells, providing new insights into Tcf1-dependent regulatory programs in step-wise governing NK cell development.

Musculin is highly enriched in Th17 and IL-22-producing ILC3s and restrains pro-inflammatory cytokines in murine colitis.

Transcription suppressor Musculin (MSC) is enriched in pro-inflammatory Th17 and IL-22-producing ILC3s. While MSC+/+ mice survived DSS-induced colitis, MSC-/- mice showed elevated pro-inflammatory cytokines with severer pathology, reduced body weight, and earlier death. Reversal of colitis symptoms in MSC-/- mice by IL-22 antagonism suggests the existence of MSC:IL-22 regulatory axis.

Serum soluble VSIG4 as a surrogate marker for the diagnosis of lymphoma-associated hemophagocytic lymphohistiocytosis.

Lymphoma-associated haemophagocytic lymphohistiocytosis (L-HLH) is characterized by excessively activated macrophages and cytotoxic T lymphocytes, but few reliable markers for activated macrophages are available clinically. This study, designed to discover novel biomarkers for the diagnosis of lymphoma patients with L-HLH, was initiated between 2016 and 2018. Fifty-seven adult lymphoma patients were enrolled - 39 without HLH and 18 with HLH. The differential serum protein expression profile was first screened between lymphoma patients with and without L-HLH by a quantitative mass spectrometric approach. Soluble V-set and immunoglobulin domain-containing 4 (sVSIG4), specifically expressed by macrophages, was significantly upregulated in the L-HLH group. Subsequently, sVSIG4 concentration was confirmed by enzyme-linked immunosorbent assay to be significantly increased in lymphoma patients with L-HLH. When it was exploited for the diagnosis of lymphoma patients with L-HLH, the area under a receiver operating characteristic curve was 0·98 with an optimal cut-off point of 2195 pg/ml and the corresponding sensitivity and specificity were 94·44% and 94·87% respectively. In addition, the one-year overall survival was significantly worse in patients with a sVSIG4 concentration above 2195 pg/ml compared with those below 2195 pg/ml (5·3% vs. 72·2%, P < 0·0001). sVSIG4 may be a surrogate marker of activated macrophages for the diagnosis of lymphoma patients with L-HLH.

Gentamicin Induced Microbiome Adaptations Associate With Increased BCAA Levels and Enhance Severity of Influenza Infection.

Involvement of gut microbiota in pulmonary disease by the gut-lung axis has been widely observed. However, the cross-talk messengers between respiratory mucosal immunity and gut microbiota are largely unknown. Using selective pharmacologic destruction of gut microenvironment mouse models, we found gut microbiota displayed significantly lower alpha diversity and relative abundance of bacteria in Gentamicin treated mice. Metagenomic studies revealed functional differences in gut bacteria in altering metabolic profiles in mice blood. Branched-chain amino acids (BCAAs) are the essential factors linked between gut and lung. During this process, selective destruction of gut microbiota by Gentamicin induced high levels of BCAAs, and the high levels of BCAAs impacted the lung immunity against influenza virus. In vivo, Gentamicin-treated mice or mice fed with high BCAAs diets displayed reduced survival. At the sites of infection, the number of CD11b+Ly6G+ cells decreased, and CD8+ T cells increased accompanied by exuberant expression of pro-inflammatory cytokines could result in tissue damage. CD11b+Ly6G+ cells transplantation conferred remarkable protection from influenza virus infections. In vitro, BCAAs promoted bone marrow-derived cells differentiation to dendritic cells. Taken together, these findings demonstrate that Gentamicin induced disruption of the gut microbiota leads to increased BCAA levels that suppress CD11b+Ly6c+ cell development in association with overactive CD8+ T responses which may contribute to enhanced severity of the viral infection.

[Exploration of the Role of Tumor Suppressor Genes Foxo1 and PTEN in the Tumorigenesis of Mouse Natural Killer-Cell Lymphoma].

OBJECTIVE: To explore whether tumor suppressor gene Foxo1 and PTEN play a critical role in the tumorigenesis of mouse natural killer-cell lymphoma. METHODS: NKp46-iCre mice were crossed with mice carrying floxed Foxo1 alleles (Foxo1fl/fl) as well as floxed PTEN alleles (PTENfl/fl) to generate mice in which Foxo1 and PTEN in NK cells were knock-out, referred as Foxo1△NKPTEN△NK. The growth and development of the mice and tumor formation were observed. The flow cytometry was used to detect the percentages of NK cells in main lymphatic organs. B16F10 metanoma model of tumor metastasis was utilized to investigate NK cell-mediated tumor surveillance in vivo after NK cells special deletion of Foxol and PTEN. RESULTS: The mouse model with NK cell-special Foxo1 and PTEN double knockout was established. Compared with control group (Foxo1fl/flPTENfl/fl mice), Foxo1△NKPTEN△NK mice were born alive and appeared to be healthy over a period of 46 weeks. No spontaneous tumor formation was observed at this stage. There were no significant differences in NK cell percentages of gated lymphocytes from various organs including blood, bone marrow, peripheral lymph node and spleen between Foxo1△NKPTEN△NK mice and Foxo1fl/flPTENfl/fl mice [PB: 4.76%±0.46% vs 4.17%±0.64% (P＞0.05, n=8); BM: 1.13%±0.23% vs 1.31%±0.10% (P＞0.05, n=8) ; LN: 0.50%±0.10% vs 0.85%±0.20% (P＞0.05, n=8); SP: 4.41%±0.65% vs 3.50%±0.24% (P＞0.05, n=8)]. B16F10 melanoma metastasis model of tumor was established, No differences in median survival time were observed in the 2 types of mice (P＞0.05, n=13). CONCLUSION: The simultaneous deletion of the Foxo1 and PTEN genes may not plays significant role in the tumorigenesis of mouse natural killer-cell lymphoma and NK cell-mediated tumor surveillance in vivo.

Crosstalks between mTORC1 and mTORC2 variagate cytokine signaling to control NK maturation and effector function.

The metabolic checkpoint kinase mechanistic/mammalian target of rapamycin (mTOR) regulates natural killer (NK) cell development and function, but the exact underlying mechanisms remain unclear. Here, we show, via conditional deletion of Raptor (mTORC1) or Rictor (mTORC2), that mTORC1 and mTORC2 promote NK cell maturation in a cooperative and non-redundant manner, mainly by controlling the expression of Tbx21 and Eomes. Intriguingly, mTORC1 and mTORC2 regulate cytolytic function in an opposing way, exhibiting promoting and inhibitory effects on the anti-tumor ability and metabolism, respectively. mTORC1 sustains mTORC2 activity by maintaining CD122-mediated IL-15 signaling, whereas mTORC2 represses mTORC1-modulated NK cell effector functions by restraining STAT5-mediated SLC7A5 expression. These positive and negative crosstalks between mTORC1 and mTORC2 signaling thus variegate the magnitudes and kinetics of NK cell activation, and help define a paradigm for the modulation of NK maturation and effector functions.

Role of IL-18 in transplant biology.

Since pro-inflammatory cytokine IL-18 and its receptor (IL-18R) are closely involved in regulating both adaptive and innate immune responses, it is conceivable that they might play an important role in organ transplantation. IL-18 can stimulate lymphocytes to produce the IFN-γ and regulate macrophage activity, thereby increasing the expression of proinflammatory cytokines including IL-1ß, IL-6, CCL4 (macrophage inflammatory protein-1 ß), CXCL2 (macrophage inflammatory protein-2), and CCL2 (monocyte chemotactic protein-1). Nevertheless, the IL-18 signaling pathway and its underlying mechanisms remain obscure in transplant biology. This review is to summarize recent advances in our knowledge about the IL-18 signaling pathway and to analyze their functions in transplant-related biology. It was found that IL-18/IL-18R signaling pathway contributed to vascular transplantation, ischemmia/reperfusion, acute kidney injury, and acute rejection of kidney/liver/heart transplantation. IL-18 was a potential CYP3A expression modulator and was capable of affecting tacrolimus pharmacokinetics. Neutralizing IL-18 by its inhibitor IL-18 binding protein could efficiently suppress the production of injury-associated cytokines such as IL-6, TNF-α, IFN-γ, CXCL10 (IFN-γ-inducible protein10), and CX3CL1 (fractalkine) and improve allograft function. Blockade of IL-18 signaling could regulate cardiomyocyte apoptosis and inhibit Th17 cells differentiation. Alteration of IL-18 levels was suggested as a biomarker for predicting ongoing allograft outcome. All these activities could deepen our understanding of immunobiological role of IL-18 and its receptor in the field of organ transplantation. Intervention of IL-18 signaling pathway might be utilized as a therapeutic strategy in clinic.

[Retrospective Analysis of Clinical Features and Prognosis of 84 Patients with Extranodal NK/T Cell Lymphoma in One Center].

OBJECTIVE: To investigate the clinical characteristics, treatment and prognostic factors of patients with extranodal NK/T cell lymphoma. METHODS: The clinical data of patients with extranodal NK/T cell lymphoma admitted in the Hospital Affiliated to the Academy of Military Medical Science from June 2006 to June 2016 were retrospectively analyzed. The clinical features, therapeutic efficacy and prognosis-related factors were clarified. RESULTS: A total of 84 patients with extranodal NK/T cell lymphoma with complete clinical data were collected, with a median follow-up of 21 months (1-123 months), the overall survival (OS) and progression free survival (PFS) were 58.9% and 52.1% years, respectively. Univariate analysis showed that anemia, the copy number of EBV-DNA, LDH level, IPI score, ECOG score, Ann Arbor staging, complete remission after the initial therapy were statistically significant for both OS and PFS of the patients, and chemotherapy regimens were only statistically significant for PFS. Multivariate analysis showed that complete remission after the initial therapy, LDH level and ECOG score were statistically significant for both OS and PFS in patients with NK/T cell lymphoma. CONCLUSION: LDH level, ECOG score and complete remission after the initial therapy are independent prognostic factors for patients with extranodal NK/T cell lymphoma.

Decreasing Eukaryotic Initiation Factor 3C (EIF3C) Suppresses Proliferation and Stimulates Apoptosis in Breast Cancer Cell Lines Through Mammalian Target of Rapamycin (mTOR) Pathway.

BACKGROUND Translation initiation is the rate limiting step of protein synthesis and is highly regulated. Eukaryotic initiation factor 3C (EIF3C), an oncogene overexpressed in several human cancers, plays an important role in tumorigenesis and cell proliferation. MATERIAL AND METHODS Immunohistochemistry was used to determine the expression of EIF3C in breast cancer tissues from 42 patients. We investigated whether EIF3C silencing decreases breast cancer cell proliferation as assessed by colony formation assay, and whether EIF3C gene knockdown induces apoptosis as assessed by flow cytometry analysis. We utilized the stress and apoptosis signaling antibody array kit, while p-ERK1/2, p-Akt, p-Smad2, p-p38 MAPK, cleaved caspase-3, and cleaved caspase-7 were explored between EIF3C-siRNA and controls. Furthermore, the effects of EIF3C gene knockdown in mTOR pathway were analyzed by western blotting for different cell lines. RESULTS In EIF3C-positive tumors, 32 out of 42 showed significantly higher frequencies of high grade group by immunoreactivity (p=0.0016). BrdU incorporation after four days of cell plating was significantly suppressed in MDA-MB-231 cells by EIF3C knockdown compared with controls, with average changes of 7.8-fold (p<0.01). Clone number was significantly suppressed in MDA-MB-231 cells by EIF3C knockdown compared with controls (p<0.05). Cell apoptosis was significantly increased in the EIF3C-siRNA group when compared with the cells that were transfected with scrambled siRNA (3.51±0.0842 versus 13.24±0.2307, p<0.01). The mTOR signaling pathway was involved in decreasing EIF3C translational efficiency. CONCLUSIONS Unveiling the mechanisms of EIF3 action in tumorigenesis may help identify attractive targets for cancer therapy.

Transcription factor Foxo1 is a negative regulator of natural killer cell maturation and function.

Little is known about the role of negative regulators in controlling natural killer (NK) cell development and effector functions. Foxo1 is a multifunctional transcription factor of the forkhead family. Using a mouse model of conditional deletion in NK cells, we found that Foxo1 negatively controlled NK cell differentiation and function. Immature NK cells expressed abundant Foxo1 and little Tbx21 relative to mature NK cells, but these two transcription factors reversed their expression as NK cells proceeded through development. Foxo1 promoted NK cell homing to lymph nodes by upregulating CD62L expression and inhibited late-stage maturation and effector functions by repressing Tbx21 expression. Loss of Foxo1 rescued the defect in late-stage NK cell maturation in heterozygous Tbx21(+/-) mice. Collectively, our data reveal a regulatory pathway by which the negative regulator Foxo1 and the positive regulator Tbx21 play opposing roles in controlling NK cell development and effector functions.

AID-initiated DNA lesions are differentially processed in distinct B cell populations.

Activation-induced deaminase (AID) initiates U:G mismatches, causing point mutations or DNA double-stranded breaks at Ig loci. How AID-initiated lesions are prevented from inducing genome-wide damage remains elusive. A differential DNA repair mechanism might protect certain non-Ig loci such as c-myc from AID attack. However, determinants regulating such protective mechanisms are largely unknown. To test whether target DNA sequences modulate protective mechanisms via altering the processing manner of AID-initiated lesions, we established a knock-in model by inserting an Sγ2b region, a bona fide AID target, into the first intron of c-myc. Unexpectedly, we found that the inserted S region did not mutate or enhance c-myc genomic instability, due to error-free repair of AID-initiated lesions, in Ag-stimulated germinal center B cells. In contrast, in vitro cytokine-activated B cells display a much higher level of c-myc genomic instability in an AID- and S region-dependent manner. Furthermore, we observe a comparable frequency of AID deamination events between the c-myc intronic sequence and inserted S region in different B cell populations, demonstrating a similar frequency of AID targeting. Thus, our study reveals a clear difference between germinal center and cytokine-activated B cells in their ability to develop genomic instability, attributable to a differential processing of AID-initiated lesions in distinct B cell populations. We propose that locus-specific regulatory mechanisms (e.g., transcription) appear to not only override the effects of S region sequence on AID targeting frequency but also influence the repair manner of AID-initiated lesions.