The pathogenesis of pulmonary fibrosis (PF) is complex. It is characterized by myofibroblast hyperplasia and deposition of collagen protein. Indoleamine 2,3-dioxygenase 1 (IDO1) is expressed in lung fibroblasts and epithelial cells, but its functions in lung homeostasis and diseases remain elusive. Here, we characterize the critical role of IDO1 in PF patients and bleomycin (BLM)-induced PF mouse models. We find that IDO1 is significantly upregulated in the fibrotic lungs of patients and mice, showing a positive correlation with genes characteristic of fibrosis. Functionally, IDO1 knockout inhibits lung fibroblast proliferation, differentiation, mitochondrial biogenesis, and mitochondrial oxidative phosphorylation. Conversely, IDO1 overexpression and accumulation of kynurenine (Kyn) exacerbate progressive lung fibrosis. Mechanistically, IDO1-deletion activated profound mitochondrial fusion-enhanced potentially the capacity for fatty acid oxidation, along with activation of de novo glycolytic serine/glycine synthesis pathways and mitochondrial one-carbon metabolism. Wedelolactone (WEL), a small molecule IKK inhibitor, is found to strongly bind to IDO1 and effectively protect mice from PF in an IDO1-dependent manner. Collectively, this study characterizes a promotor role for IDO1 in PF and suggests a potential avenue of targeting IDO1 to treat lung diseases.

Background::T-cell-mediated immunity is crucial for the effective clearance of viral infection, but the T-cell-mediated immune responses that are induced by booster doses of inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in people living with human immunodeficiency virus (PLWH) remain unclear.Methods::Forty-five PLWH who had received antiretroviral therapy (ART) for more than two years and 29 healthy controls (HCs) at Beijing Youan Hospital were enrolled to assess the dynamic changes in T-cell responses between the day before the third vaccine dose (week 0) and 4 or 12 weeks (week 4 or week 12) after receiving the third dose of inactivated SARS-CoV-2 vaccine. Flow cytometry, enzyme-linked immunospot (ELISpot), and multiplex cytokines profiling were used to assess T-cell responses at the three timepoints in this study.Results::The results of the ELISpot and activation-induced marker (AIM) assays showed that SARS-CoV-2-specific T-cell responses were increased in both PLWH and HCs after the third dose of the inactivated SARS-CoV-2 vaccine, and a similar magnitude of immune response was induced against the Omicron (B.1.1.529) variant compared to the wild-type strain. In detail, spike-specific T-cell responses (measured by the ELISpot assay for interferon γ [IFN-γ] release) in both PLWH and HCs significantly increased in week 4, and the spike-specific T-cell responses in HCs were significantly stronger than those in PLWH 4 weeks after the third vaccination. In the AIM assay, spike-specific CD4 + T-cell responses peaked in both PLWH and HCs in week 12. Additionally, significantly higher spike-specific CD8 + T-cell responses were induced in PLWH than in HCs in week 12. In PLWH, the release of the cytokines interleukin-2 (IL-2), tumour necrosis factor-alpha (TNF-α), and IL-22 by peripheral blood mononuclear cells (PBMCs) that were stimulated with spike peptides increased in week 12. In addition, the levels of IL-4 and IL-5 were higher in PLWH than in HCs in week 12. Interestingly, the magnitude of SARS-CoV-2-specific T-cell responses in PLWH was negatively associated with the extent of CD8 + T-cell activation and exhaustion. In addition, positive correlations were observed between the magnitude of spike-specific T-cell responses (determined by measuring IFN-γ release by ELISpot) and the amounts of IL-4, IL-5, IL-2 and IL-17F. Conclusions::Our findings suggested that SARS-CoV-2-specific T-cell responses could be enhanced by the booster dose of inactivated COVID-19 vaccines and further illustrate the importance of additional vaccination for PLWH.

Background::Cluster of differentiation 8 (CD8 T) cells play critical roles in eradicating human immunodeficiency virus (HIV)-1 infection, but little is known about the effects of T cells expressing CD8 at low levels (CD8 low) or high levels (CD8 high) on HIV-1 replication inhibition after HIV-1 invasion into individual. Methods::Nineteen patients who had been acutely infected with HIV-1 (AHI) and 20 patients with chronic infection (CHI) for ≥2 years were enrolled in this study to investigate the dynamics of the quantity, activation, and immune responses of CD3 +CD8 low T cells and their counterpart CD3 +CD8 high T cells at different stages of HIV-1 infection. Results::Compared with healthy donors, CD3 +CD8 low T cells expanded in HIV-1-infected individuals at different stages of infection. As HIV-1 infection progressed, CD3 +CD8 low T cells gradually decreased. Simultaneously, CD3 +CD8 high T cells was significantly reduced in the first month of AHI and then increased gradually as HIV-1 infection progressed. The classical activation of CD3 +CD8 low T cells was highest in the first month of AHI and then reduced as HIV-1 infection progressed and entered the chronic stage. Meanwhile, activated CD38 -HLA-DR +CD8 low T cells did not increase in the first month of AHI, and the number of these cells was inversely associated with viral load ( r = -0.664, P = 0.004) but positively associated with the CD4 T-cell count ( r = 0.586, P = 0.014). Increased programmed cell death protein 1 (PD-1) abundance on CD3 +CD8 low T cells was observed from the 1st month of AHI but did not continue to be enhanced, while a significant T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif (ITIM) domains (TIGIT) abundance increase was observed in the 12th month of infection. Furthermore, increased PD-1 and TIGIT abundance on CD3 +CD8 low T cells was associated with a low CD4 T-cell count (PD-1: r = -0.456, P = 0.043; TIGIT: r = -0.488, P = 0.029) in CHI. Nonetheless, the nonincrease in PD-1 expression on classically activated CD3 +CD8 low T cells was inversely associated with HIV-1 viremia in the first month of AHI ( r = -0.578, P = 0.015). Notably, in the first month of AHI, few CD3 +CD8 low T cells, but comparable amounts of CD3 +CD8 high T cells, responded to Gag peptides. Then, weaker HIV-1-specific T-cell responses were induced in CD3 +CD8 low T cells than CD3 +CD8 high T cells at the 3rd and 12th months of AHI and in CHI. Conclusions::Our findings suggest that CD3 +CD8 low T cells play an anti-HIV role in the first month of infection due to their abundance but induce a weak HIV-1-specific immune response. Subsequently, CD3 +CD8 low T-cell number decreased gradually as infection persisted, and their anti-HIV functions were inferior to those of CD3 +CD8 high T cells.

The unicellular green alga Chlamydomonas reinhardtii (hereafter Chlamydomonas) possesses both plant and animal attributes, and it is an ideal model organism for studying fundamental processes such as photosynthesis, sexual reproduction, and life cycle. N⁶-methyladenosine (m⁶A) is the most prevalent mRNA modification, and it plays important roles during sexual reproduction in animals and plants. However, the pattern and function of m⁶A modification during the sexual reproduction of Chlamydomonas remain unknown. Here, we performed transcriptome and methylated RNA immunoprecipitation sequencing (MeRIP-seq) analyses on six samples from different stages during sexual reproduction of the Chlamydomonas life cycle. The results show that m⁶A modification frequently occurs at the main motif of DRAC (D = G/A/U, R = A/G) in Chlamydomonas mRNAs. Moreover, m⁶A peaks in Chlamydomonas mRNAs are mainly enriched in the 3' untranslated regions (3'UTRs) and negatively correlated with the abundance of transcripts at each stage. In particular, there is a significant negative correlation between the expression levels and the m⁶A levels of genes involved in the microtubule-associated pathway, indicating that m⁶A modification influences the sexual reproduction and the life cycle of Chlamydomonas by regulating microtubule-based movement. In summary, our findings are the first to demonstrate the distribution and the functions of m⁶A modification in Chlamydomonas mRNAs and provide new evolutionary insights into m⁶A modification in the process of sexual reproduction in other plant organisms.
Animals ; Chlamydomonas reinhardtii/metabolism* ; Reproduction/genetics* ; Life Cycle Stages/genetics* ; Transcriptome ; Plants/genetics*

After implantation, complex and highly specialized molecular events render functionally distinct organ formation, whereas how the epigenome shapes organ-specific development remains to be fully elucidated. Here, nano-hmC-Seal, RNA bisulfite sequencing (RNA-BisSeq), and RNA sequencing (RNA-Seq) were performed, and the first multilayer landscapes of DNA 5-hydroxymethylcytosine (5hmC) and RNA 5-methylcytosine (m⁵C) epigenomes were obtained in the heart, kidney, liver, and lung of the human foetuses at 13-28 weeks with 123 samples in total. We identified 70,091 and 503 organ- and stage-specific differentially hydroxymethylated regions (DhMRs) and m⁵C-modified mRNAs, respectively. The key transcription factors (TFs), T-box transcription factor 20 (TBX20), paired box 8 (PAX8), krueppel-like factor 1 (KLF1), transcription factor 21 (TCF21), and CCAAT enhancer binding protein beta (CEBPB), specifically contribute to the formation of distinct organs at different stages. Additionally, 5hmC-enriched Alu elements may participate in the regulation of expression of TF-targeted genes. Our integrated studies reveal a putative essential link between DNA modification and RNA methylation, and illustrate the epigenetic maps during human foetal organogenesis, which provide a foundation for for an in-depth understanding of the epigenetic mechanisms underlying early development and birth defects.
Humans ; DNA Methylation ; RNA ; Epigenesis, Genetic ; DNA/genetics* ; Basic Helix-Loop-Helix Transcription Factors/genetics*

Studies have investigated the effects of androgen deprivation therapy (ADT) use on the incidence and clinical outcomes of coronavirus disease 2019 (COVID-19); however, the results have been inconsistent. We searched the PubMed, Medline, Cochrane, Scopus, and Web of Science databases from inception to March 2022; 13 studies covering 84 003 prostate cancer (PCa) patients with or without ADT met the eligibility criteria and were included in the meta-analysis. We calculated the pooled risk ratios (RRs) with 95% confidence intervals (CIs) to explore the association between ADT use and the infection risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and severity of COVID-19. After synthesizing the evidence, the pooled RR in the SARS-CoV-2 positive group was equal to 1.17, and the SARS-CoV-2 positive risk in PCa patients using ADT was not significantly different from that in those not using ADT (P = 0.544). Moreover, no significant results concerning the beneficial effect of ADT on the rate of intensive care unit admission (RR = 1.04, P = 0.872) or death risk (RR = 1.23, P = 0.53) were found. However, PCa patients with a history of ADT use had a markedly higher COVID-19 hospitalization rate (RR = 1.31, P = 0.015) than those with no history of ADT use. These findings indicate that ADT use by PCa patients is associated with a high risk of hospitalization during infection with SARS-CoV-2. A large number of high quality studies are needed to confirm these results.
Male ; Humans ; Prostatic Neoplasms/chemically induced* ; Androgen Antagonists/adverse effects* ; COVID-19 ; Androgens/therapeutic use* ; SARS-CoV-2

Malfunction of the ventral subiculum (vSub), the main subregion controlling the output connections from the hippocampus, is associated with major depressive disorder (MDD). Although the vSub receives cholinergic innervation from the medial septum and diagonal band of Broca (MSDB), whether and how the MSDB-to-vSub cholinergic circuit is involved in MDD is elusive. Here, we found that chronic unpredictable mild stress (CUMS) induced depression-like behaviors with hyperactivation of vSub neurons, measured by c-fos staining and whole-cell patch-clamp recording. By retrograde and anterograde tracing, we confirmed the dense MSDB cholinergic innervation of the vSub. In addition, transient restraint stress in CUMS increased the level of ACh in the vSub. Furthermore, chemogenetic stimulation of this MSDB-vSub innervation in ChAT-Cre mice induced hyperactivation of vSub pyramidal neurons along with depression-like behaviors; and local infusion of atropine, a muscarinic receptor antagonist, into the vSub attenuated the depression-like behaviors induced by chemogenetic stimulation of this pathway and CUMS. Together, these findings suggest that activating the MSDB-vSub cholinergic pathway induces hyperactivation of vSub pyramidal neurons and depression-like behaviors, revealing a novel circuit underlying vSub pyramidal neuronal hyperactivation and its associated depression.
Rats ; Mice ; Animals ; Rats, Sprague-Dawley ; Depressive Disorder, Major/metabolism* ; Basal Forebrain ; Depression ; Hippocampus/metabolism* ; Cholinergic Agents

Platycodon grandiflorum (Jacq.) A. DC. is a famous medicinal plant commonly used in East Asia. Triterpene saponins isolated from P. grandiflorum are the main biologically active compounds, among which polygalacin D (PGD) has been reported to be an anti-tumor agent. However, its anti-tumor mechanism against hepatocellular carcinoma is unknown. This study aimed to explore the inhibitory effect of PGD in hepatocellular carcinoma cells and related mechanisms of action. We found that PGD exerted significant inhibitory effect on hepatocellular carcinoma cells through apoptosis and autophagy. Analysis of the expression of apoptosis-related proteins and autophagy-related proteins revealed that this phenomenon was attributed to the mitochondrial apoptosis and mitophagy pathways. Subsequently, using specific inhibitors, we found that apoptosis and autophagy had mutually reinforcing effects. In addition, further analysis of autophagy showed that PGD induced mitophagy by increasing BCL2 interacting protein 3 like (BNIP3L) levels.In vivo experiments demonstrated that PGD significantly inhibited tumor growth and increased the levels of apoptosis and autophagy in tumors. Overall, our findings showed that PGD induced cell death of hepatocellular carcinoma cells primarily through mitochondrial apoptosis and mitophagy pathways. Therefore, PGD can be used as an apoptosis and autophagy agonist in the research and development of antitumor agents.
Humans ; Mitophagy ; Carcinoma, Hepatocellular/pathology* ; Liver Neoplasms/pathology* ; Cell Line ; Autophagy ; Apoptosis ; Membrane Proteins ; Proto-Oncogene Proteins/genetics* ; Tumor Suppressor Proteins/pharmacology*

Although antiretroviral therapy (ART) can reduce the viral load in the plasma to undetectable levels in human immunodeficiency virus (HIV)-infected individuals, ART alone cannot completely eliminate HIV due to its integration into the host cell genome to form viral reservoirs. To achieve a functional cure for HIV infection, numerous preclinical and clinical studies are underway to develop innovative immunotherapies to eliminate HIV reservoirs in the absence of ART. Early studies have tested adoptive T-cell therapies in HIV-infected individuals, but their effectiveness was limited. In recent years, with the technological progress and great success of chimeric antigen receptor (CAR) therapy in the treatment of hematological malignancies, CAR therapy has gradually shown its advantages in the field of HIV infection. Many studies have identified a variety of HIV-specific CAR structures and types of cytolytic effector cells. Therefore, CAR therapy may be beneficial for enhancing HIV immunity, achieving HIV control, and eliminating HIV reservoirs, gradually becoming a promising strategy for achieving a functional HIV cure. In this review, we provide an overview of the design of anti-HIV CAR proteins, the cell types of anti-HIV CAR (including CAR T cells, CAR natural killer cells, and CAR-encoding hematopoietic stem/progenitor cells), the clinical application of CAR therapy in HIV infection, and the prospects and challenges in anti-HIV CAR therapy for maintaining viral suppression and eliminating HIV reservoirs.
Humans ; Immunotherapy, Adoptive ; HIV Infections/therapy* ; HIV-1

BACKGROUND: T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domains (TIGIT), an inhibitory receptor expressed on T cells, plays a dysfunctional role in antiviral infection and antitumor activity. However, it is unknown whether TIGIT expression on T cells influences the immunological effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivated vaccines. METHODS: Forty-five people living with HIV (PLWH) on antiretroviral therapy (ART) for more than two years and 31 healthy controls (HCs), all received a third dose of a SARS-CoV-2 inactivated vaccine, were enrolled in this study. The amounts, activation, proportion of cell subsets, and magnitude of the SARS-CoV-2-specific immune response of TIGIT + CD4 + and TIGIT + CD8 + T cells were investigated before the third dose but 6 months after the second vaccine dose (0W), 4 weeks (4W) and 12 weeks (12W) after the third dose. RESULTS: Compared to that in HCs, the frequency of TIGIT + CD8 + T cells in the peripheral blood of PLWH increased at 12W after the third dose of the inactivated vaccine, and the immune activation of TIGIT + CD8 + T cells also increased. A decrease in the ratio of both T naïve (T N ) and central memory (T CM ) cells among TIGIT + CD8 + T cells and an increase in the ratio of the effector memory (T EM ) subpopulation were observed at 12W in PLWH. Interestingly, particularly at 12W, a higher proportion of TIGIT + CD8 + T cells expressing CD137 and CD69 simultaneously was observed in HCs than in PLWH based on the activation-induced marker assay. Compared with 0W, SARS-CoV-2-specific TIGIT + CD8 + T-cell responses in PLWH were not enhanced at 12W but were enhanced in HCs. Additionally, at all time points, the SARS-CoV-2-specific responses of TIGIT + CD8 + T cells in PLWH were significantly weaker than those of TIGIT - CD8 + T cells. However, in HCs, the difference in the SARS-CoV-2-specific responses induced between TIGIT + CD8 + T cells and TIGIT - CD8 + T cells was insignificant at 4W and 12W, except at 0W. CONCLUSIONS TIGIT expression on CD8 + T cells may hinder the T-cell immune response to a booster dose of an inactivated SARS-CoV-2 vaccine, suggesting weakened resistance to SARS-CoV-2 infection, especially in PLWH. Furthermore, TIGIT may be used as a potential target to increase the production of SARS-CoV-2-specific CD8 + T cells, thereby enhancing the effectiveness of vaccination.
Humans ; Antibodies, Viral ; CD8-Positive T-Lymphocytes ; COVID-19/complications* ; COVID-19 Vaccines/immunology* ; HIV Infections/complications* ; Receptors, Immunologic ; SARS-CoV-2