Objective To construct a library of human-derived anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) single-chain variable fragments (scFv) and screen for broad-spectrum neutralizing antibodies to identify candidate molecules for the development of diagnostic and therapeutic agents. Methods Peripheral blood mononuclear cells (PBMCs) were isolated from the peripheral blood of patients who had recovered from novel coronavirus infection. Total RNA was extracted from these PBMCs and reverse transcribed into cDNA, which was used as a template for constructing a human anti-SARS-CoV-2 scFv library. Phage display technology was used to screen for scFv antibodies specific to the SARS-CoV-2 S protein. Full-length IgG antibodies were synthesized through sequence analysis and human IgG expression, and their binding capacity and neutralizing activity against SARS-CoV-2 were evaluated. Results A human-derived scFv antibody library against SARS-CoV-2 with a capacity of 1.56×10⁷ CFU was successfully constructed. Two specific scFv antibodies were screened from this library and expressed as full-length IgG antibodies (IgG-A10 and IgG-G6). IgG-A10 exhibited strong neutralizing activity against both the original SARS-CoV-2 strain (WT) and the XBB subvariant of the Omicron variant. However, the neutralizing activity of this antibody against the JN.1 sub lineage of the Omicron BA.2.86 variant was moderate. Conclusion This study has successfully constructed a human anti-SARS-CoV-2 scFv antibody library from the peripheral blood of recovered patients, and screened and expressed anti-SARS-CoV-2 IgG antibodies with neutralizing activity, laying a foundation for the prevention, diagnosis, and treatment of SARS-CoV-2 infection.
Humans ; Single-Chain Antibodies/genetics* ; SARS-CoV-2/immunology* ; COVID-19/immunology* ; Immunoglobulin G/genetics* ; Antibodies, Viral/genetics* ; Peptide Library ; Spike Glycoprotein, Coronavirus/immunology* ; Antibodies, Neutralizing/immunology* ; Leukocytes, Mononuclear/immunology* ; Broadly Neutralizing Antibodies/immunology*

Objective To explore the alterations in macrophage polarization and the expression of decorin (DCN) protein in the decidua of patients with missed abortion (MA), as well as to elucidate the regulatory effect of DCN on macrophage polarization. Methods Flow cytometry was employed to assess the polarization ratio of decidual macrophages in MA, recurrent spontaneous abortion (RSA) and normal pregnancy (NP); The expression and localization of DCN and hypoxia-inducible factor 1α (HIF-1α) in decidua and villi were assessed by immunohistochemistry staining, while their protein levels were measured by Western blot. Primary trophoblasts and peripheral blood mononuclear cell (PBMC)-derived macrophages were isolated and cultured. ELISA was conducted to quantify DCN levels in the culture supernatant of primary trophoblast and PBMC-derived macrophages. Additionally, flow cytometry was applied to evaluate the polarization ratio of PBMC-derived macrophages. Immunofluorescence cytochemical staining was conducted to examine HIF-1α expression in macrophages. Western blot was performed to detect the expression of proteins related to the gene associated with retinoid-IFN-induced mortality 19 (GRIM-19)/signal transducer and activator of transcription 3 (STAT3)/HIF-1α signaling pathway in macrophages. Results The polarization ratio of M1 macrophages in the decidua of abortion patients was significantly higher than that of NP, whereas the ratio of M2 macrophages was significantly lower. The expression of DCN and HIF-1α protein were significantly evaluated in abortion patients compared to NP. The supernatant DCN content and HIF-1α protein expression of primary trophoblast and PBMC-derived macrophages cultured under 10 mL/L O₂ for 24 hours were markedly increased compared to cells treated with 210 mL/L O₂. Compared with the PBS group, the proportion of M1 macrophage and GRIM-19 protein expression were significantly reduced in the DCN group, while phosphorylated STAT3 (p-STAT3) and HIF-1α protein expression were significantly increased. Conclusion The expression of DCN in decidua and villi of MA is higher than that of NP. DCN exhibits an inhibitory effect on the M1 polarization of PBMCs-derived macrophages, which is likely mediated through the GRIM-19/STAT3/HIF-1α signaling pathway.
Humans ; Female ; Decidua/metabolism* ; Macrophages/cytology* ; Decorin/genetics* ; Pregnancy ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Adult ; Leukocytes, Mononuclear/cytology* ; Abortion, Missed/genetics* ; STAT3 Transcription Factor/metabolism* ; Cells, Cultured ; Young Adult

OBJECTIVE: To investigate the expression of CSF-1 and CSF-1R in the peripheral blood of children with immune thrombocytopenia (ITP) and its clinical significance. METHODS: Forty-four children with ITP treated in our hospital from February 2023 to January 2024 were selected as the observation group, and 40 healthy children were selected as the control group during the same period, and relevant clinical data were collected. Peripheral blood mononuclear cells (PBMC) of children with ITP and healthy children were separated, and the plasma levels of M1 macrophage-associated cytokines (TNF-α, IL-6), M2 macrophage-associated cytokines (IL-10, TGF-β), and CSF-1 were detected by ELISA in the children of both groups. The mRNA levels of M1 macrophage surface markers (CD86, iNOS), M2 macrophage surface markers (CD206, Arg-1) and CSF-1R were detected by RT-PCR in PBMC of children in both groups. Western blot was used to detect the expression of CSF-1R protein in PBMC of the two groups of children. The correlation between platelet count and CSF-1R mRNA expression in PBMC, TNF-α, IL-6, IL-10, TGF-β and CSF-1 in plasma was analyzed. RESULTS: Compared with the control group, the levels of IL-10, TGF-β, CSF-1 and platelet count in plasma of children with ITP were significantly decreased (P < 0.01), and the levels of TNF-α and IL-6 were significantly increased (P < 0.01); the mRNA levels of the M1 macrophage surface markers (CD86, iNOS) in PBMC of children with ITP were significantly increased (P < 0.05), mRNA levels of M2 macrophage surface marker CD206 in PBMC of children with ITP were decreased compared with controls but the difference was not statistically significant ( P >0.05), mRNA levels of Arg-1 were decreased, the difference was statistically significant (P < 0.05). The mRNA and protein levels of CSF-1R in PBMC of ITP children were higher than that in controls. CSF-1R expression in PBMC of ITP was positively correlated with platelet count, IL-10, CSF-1 were positively correlated (r =0.822,0.481,0.405). CONCLUSION CSF-1 is significantly reduced in the plasma of ITP, and CSF-1R mRNA and protein expression is significantly elevated in PBMC of ITP, which are involved in the regulation of macrophage M1/M2 imbalance, and could serve as a potential therapeutic target for ITP.
Humans ; Purpura, Thrombocytopenic, Idiopathic/blood* ; Macrophage Colony-Stimulating Factor/metabolism* ; Leukocytes, Mononuclear/metabolism* ; Child ; Interleukin-10/blood* ; Macrophages/metabolism* ; Tumor Necrosis Factor-alpha/blood* ; Interleukin-6/blood* ; Male ; Female ; Transforming Growth Factor beta/blood* ; Receptor, Macrophage Colony-Stimulating Factor/metabolism* ; Clinical Relevance

Ancient traditional Chinese medicine (TCM) doctrine says "The superior doctor prevents illnesses," pointing out preventative medicine as the ultimate goal for medical care. TCM recognizes that genetic predisposition and environmental and lifestyle influences contribute to diseases. It divides people into eight constitutions in addition to one normal/healthy kind. People with one of the eight subhealth constitutions are prone to develop different kinds of corresponding illnesses. The goal for this type of categorization is to help people take preemptive measures to prevent or delay disease onset. As the peripheral immune system through surveying the body, it can capture information from essentially all organs and reflect anomalies occurring in each organ. Thus, the detailed profiling of the peripheral immune-system function can generally reflect a person's overall heath state. In this study, we performed the single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells (PBMCs) from individuals with Tanshi (phlegm dampness) constitution. They were prone to develop metabolic disorders including diabetes. scRNA-seq revealed greatly reduced mucosal-associated invariable T cell content and heightened TNFα-NFκB, JAK-STAT, and interferon signaling. These findings indicated heightened chronic inflammation, as well as increased hypoxia/apoptosis responses, likely resulting from frequent sleep apnea that Tanshi individuals experienced. Altogether, this pilot study demonstrated effectiveness in using scRNA-seq to reveal molecular-immunological bases for constitution categorization, thereby substantiating that preventative medicine originated from TCM.
Humans ; Leukocytes, Mononuclear/metabolism* ; Male ; Female ; Gene Expression Profiling ; Single-Cell Analysis ; Middle Aged ; Adult ; Medicine, Chinese Traditional ; Transcriptome ; Single-Cell Gene Expression Analysis

OBJECTIVE: To obtain detailed understanding on the gene regulation of natural compounds in altering prognosis of head and neck squamous cell carcinomas (HNSC). METHODS: Gene expression data of HNSC samples and peripheral blood mononuclear cells (PBMCs) of HNSC patients were collected from Gene Expression Omnibus (GEO). Differential gene expression analysis of GEO datasets were achieved by the GEO2R tool. Common differentially expressed gerres (DEGs) were screened by comparing DEGs of HNSC with those of PBMCs. The combination was further analyzed for regulating pathways and biological processes that were affected. RESULTS: Totally 110 DEGs were retrieved and identified to be involved in biological processes related to tumor regulation. Then 102 natural compounds were screened for a combination such that the expression of all 110 commonly DEGs was altered. A combination of salidroside, ginsenoside Rd, oridonin, britanin, and scutellarein was chosen. A multifaceted, multi-dimensional tumor regression was showed by altering autophagy, apoptosis, inhibiting cell proliferation, angiogenesis, metastasis and inflammatory cytokines production. CONCLUSIONS This study has helped develop a unique combination of natural compounds that will markedly reduce the propensity of development of drug resistance in tumors and immune evasion by tumors. The result is crucial to developing a combinatorial natural therapeutic cocktail with accentuated immunotherapeutic potential.
Humans ; Leukocytes, Mononuclear ; Head and Neck Neoplasms/drug therapy* ; Squamous Cell Carcinoma of Head and Neck/drug therapy* ; Immunotherapy ; Prognosis

Objective To clarify the mechanism that HIV infection mediates mitochondrial damage of CD4⁺ T lymphocytes (CD4⁺ T cells) through mitogen-activated protein kinase (MAPK) pathway. Methods From October 1st, 2022 to March 31st, 2023, 47 HIV-infected people who received antiretroviral therapy (ART) for 4 years were recruited, including 22 immune non-responders (INR) and 25 responders (IR); and 26 sex and age-matched control participants (HC) who were negative for HCV, HBV, and HIV infections. The immune parameters were analyzed by flow cytometry. Finally, peripheral blood mononuclear cells (PBMCs) from HC or HIV patients were treated with MAPK pathway inhibitor SB203580, and the changes of mitochondrial function of CD4⁺ T cells were observed. Results Compared with HC group, the proportion of CD4⁺ T cells in PBMCs in INR group and IR group was significantly lower, and the proportion of CD4⁺ T cells in PBMCs in INR group was significantly lower than that in IR group. In addition, the proportion of naive (CD45RA⁺CD27⁺)T cells in PBMCs in INR group was significantly lower than that in HC group and IR group. Compared with HC group and IR group, the proportions of CD4⁺PD-1⁺, CD4⁺Av⁺ and CD4⁺MO⁺ in PBMCs in INR group and the proportions of CD45RA⁺CD27⁺PD-1⁺, CD45RA⁺CD27⁺Av⁺, CD45RA⁺CD27⁺MO⁺ in CD4⁺ T cell subsets increased significant. Compared with HC-con group, the basal respiration, maximal respiration and adenosine triphosphate(ATP) production of CD4⁺ T cells in HIV-con group decreased significantly, and JC-1 (green/red) in CD4⁺ T cells increased significantly. Compared with HIV-con group, the basal respiration, maximal respiration, ATP production and respiratory potential of CD4⁺ T cells in HIV-SB203580 group increased significantly, and the JC-1 (green/red) in CD4⁺ T cells decreased significantly. Conclusion Abnormal activation of the MAPK signaling pathway is observed in HIV patients receiving ART treatment, especially in CD4⁺ T cells of INR patients, which may lead to impaired mitochondrial function and abnormal CD4⁺ T cell homeostasis.
Humans ; HIV Infections/immunology* ; Male ; Mitochondria/drug effects* ; Female ; CD4-Positive T-Lymphocytes/metabolism* ; Adult ; Middle Aged ; MAP Kinase Signaling System/drug effects* ; Pyridines/pharmacology* ; Imidazoles/pharmacology* ; Leukocytes, Mononuclear/immunology*

OBJECTIVE: To investigate the regulatory effect of interferon-α (IFN-α) on the apoptosis and killing function of CD56^dimCD57⁺ natural killer (NK) cells in systemic lupus erythematosus (SLE) patients, and to explore the specific mechanism. METHODS: A total of sixty-four newly treated SLE patients and sixteen healthy controls (HC) enrolled in the Second Hospital of Dalian Medical University were selected as the research subjects. And the gene expression levels of molecules related to NK cell-killing function were detected by real-time quantitative polymerase chain reaction. CD56^dimCD57⁺ NK cells were co-cultured with the K562 cells, and the apoptotic K562 cells were labeled with Annexin-Ⅴ and 7-amino-actinomycin D. Peripheral blood mononuclear cells were treated with 20, 40, and 80 μmol/L hydrogen peroxide (H₂O₂), and treated without H₂O₂ as control, the expression level of perforin (PRF) was detected by flow cytometry. The concentration of IFN-α in serum was determined by enzyme linked immunosorbent assay. The expression levels of IFN-α receptors (IFNAR) on the surface of CD56^dimCD57⁺ NK cells were detected by flow cytometry, and were represented by mean fluorescence intensity (MFI). CD56^dimCD57⁺ NK cells were treated with 1 000 U/mL IFN-α for 24, 48 and 72 h, and no IFN-α treatment was used as the control, the apoptosis and the expression levels of mitochondrial reactive oxygen species (mtROS) were measured by flow cytometry and represented by MFI. RESULTS: Compared with HC(n=3), the expression levels of PRF1 gene in peripheral blood NK cells of the SLE patients (n=3) were decreased (1.24±0.41 vs. 0.57±0.12, P=0.05). Compared with HC(n=5), the ability of peripheral blood CD56^dimCD57⁺ NK cells in the SLE patients (n=5) to kill K562 cells was significantly decreased (58.61%±10.60% vs. 36.74%±6.27%, P < 0.01). Compared with the control (n=5, 97.51%±1.67%), different concentrations of H₂O₂ treatment significantly down-regulated the PRF expression levels of CD56^dimCD57⁺ NK cells in a dose-dependent manner, the 20 μmol/L H₂O₂ PRF was 83.23%±8.48% (n=5, P < 0.05), the 40 μmol/L H₂O₂ PRF was 79.53%±8.56% (n=5, P < 0.01), the 80 μmol/L H₂O₂ PRF was 76.67%±7.16% (n=5, P < 0.01). Compared to HC (n=16), the serum IFN-α levels were significantly increased in the SLE patients (n=45) with moderate to high systemic lupus erythematosus disease activity index (SLEDAI≥10) [(55.07±50.36) ng/L vs. (328.2±276.3) ng/L, P < 0.001]. Meanwhile, compared with HC (n=6), IFNAR1 expression in peripheral blood CD56^dimCD57⁺ NK cells of the SLE patients (n=6) were increased (MFI: 292.7±91.9 vs. 483.2±160.3, P < 0.05), and compared with HC (n=6), IFNAR2 expression in peripheral blood CD56^dimCD57⁺ NK cells of the SLE patients (n=7) were increased (MFI: 643.5±113.7 vs. 919.0±246.9, P < 0.05). Compared with control (n=6), the stimulation of IFN-α (n=6) significantly promoted the apoptosis of CD56^dimCD57⁺ NK cells (20.48%±7.01% vs. 37.82%±5.84%, P < 0.05). In addition, compared with the control (n=4, MFI: 1 049±174.5), stimulation of CD56^dimCD57⁺ NK cells with IFN-α at different times significantly promoted the production of mtROS in a time-dependent manner, 48 h MFI was 3 437±1 472 (n=4, P < 0.05), 72 h MFI was 6 495±1 089 (n=4, P < 0.000 1), but there was no significant difference at 24 h of stimulation. CONCLUSION High serum IFN-α level in SLE patients may induce apoptosis by promoting mtROS production and inhibit perforin expression, which can down-regulate CD56^dimCD57⁺ NK killing function.
Humans ; Interferon-alpha/metabolism* ; Perforin/metabolism* ; Leukocytes, Mononuclear/metabolism* ; Hydrogen Peroxide/metabolism* ; Interferon-gamma/metabolism* ; CD56 Antigen/metabolism* ; Killer Cells, Natural/metabolism* ; Lupus Erythematosus, Systemic

OBJECTIVE: To investigate the effect of circulating exosomes (EXO) on T cell function in patients with sepsis. METHODS: Plasma EXO were obtained by ultracentrifugation from 10 patients with sepsis admitted to the emergency intensive care unit of Guangdong Provincial People's Hospital Affiliated to Southern Medical University. Transmission electron microscopy observation, nanoparticle tracking analysis (NTA), and Western blotting were used to detect EXO markers to identify their characteristics. Furthermore, peripheral blood mononuclear cells (PBMC) were isolated from the peripheral blood of 5 healthy volunteers, primary T cells were sorted by magnetic beads and expanded in vitro. After 24 hours of intervention with different doses (0, 1, 2.5, 5, 10 mg/L) of circulating EXO in patients with sepsis, T-cell activity was assessed using a cell counting kit-8 (CCK-8). The expression of T cell activation indicators CD69 and CD25 were observed using flow cytometry. Additional evaluations were performed on immunosuppressive indicators including the expression of programmed cell death 1 (PD-1) in CD4⁺ T cells and the proportion of regulatory T cell (Treg). RESULTS: The identification results confirmed that the successful isolation of EXO from the plasma of sepsis patients. The expression level of circulating EXO in sepsis patients was higher than that in healthy control group (mg/L: 48.78±5.14 vs. 22.18±2.25, P < 0.01). After 24 hours of intervention with 5 mg/L of plasma EXO from sepsis patients, T cells activity began to show suppression [(85.84±0.56)% vs. (100.00±0.00)%, P < 0.05]. As the dosage increased, after 24 hours of intervention with 10 mg/L of EXO, T cells activity was significantly suppressed [(72.44±2.36)% vs. (100.00±0.00)%, P < 0.01]. Compared with the healthy control group, after T cells intervention with plasma EXO from sepsis patients, the expression of early activation marker CD69 was significantly reduced [(52.87±1.29)% vs. (67.13±3.56)%, P < 0.05]. Meanwhile, there was an upregulation of PD-1 expression in T cells [(57.73±3.06)% vs. (32.07±0.22)%, P < 0.01] and an increase in the proportion of Treg [(54.67±1.19)% vs. (24.60±3.51)%, P < 0.01]. However, the expression of the late activation marker CD25 remained stable [(84.77±3.44)% vs. (85.93±2.32)%, P > 0.05]. CONCLUSIONS Circulating EXO in sepsis patients induce T cell dysfunction, which may be a novel mechanism lead to immunosuppression in sepsis.
Humans ; Leukocytes, Mononuclear ; Exosomes/metabolism* ; Programmed Cell Death 1 Receptor/metabolism* ; T-Lymphocytes, Regulatory/metabolism* ; Sepsis/metabolism*

BACKGROUND: Immunotherapies such as adoptive immune cell infusion and immune-modulating agents are widely used for cancer treatment, and the concomitant symptoms, including cytokine release syndrome (CRS) or immune-related adverse events (irAEs), are frequently reported. However, clinical manifestations induced by mismatched donor granulocyte colony-stimulating factor mobilized peripheral blood mononuclear cell (GPBMC) infusion in patients receiving microtransplant (MST) have not yet been well depicted. METHODS: We analyzed 88 cycles of mismatched GPBMC infusion in patients with acute myeloid leukemia receiving MST and 54 cycles of chemotherapy without GPBMC infusion as a comparison. Clinical symptoms and their correlation with clinical features, laboratory findings, and clinical response were explored. RESULTS: Fever (58.0% [51/88]) and chills (43.2% [38/88]) were the significant early-onset symptoms after GPBMC infusion. Patients possessing less human leukocyte antigen-matching loci with the donor or those with unrelated donors experienced more chills (3 [2-5] loci vs. 5 [3-5] loci, P  = 0.043 and 66.7% [12/18] vs. 37.1% [26/70], P  = 0.024). On the other hand, those with decreased CD4 + /CD8 + T-cell ratio developed more fever (0.8 [0.7-1.2] vs. 1.4 [1.1-2.2], P  = 0.007). Multivariable analysis demonstrated that younger patients experienced more fever (odds ratio [OR] = 0.963, 95% confidence interval [CI]: 0.932-0.995, P  = 0.022), while patients with younger donors experienced more chills (OR = 0.915, 95% CI: 0.859-0.975, P  = 0.006). Elevated ultra-sensitive C-reactive protein levels in the absence of cytokine storm were observed following GPBMC infusion, which indicated mild and transient inflammatory response. Although no predictive value of infusion-related syndrome to leukemia burden change was found, the proportion of host pre-treatment activated T cells was positively correlated with leukemia control. CONCLUSIONS Mismatched GPBMC infusion in MST induced unique infusion-related symptoms and laboratory changes, which were associated with donor- or recipient-derived risk factors, with less safety and tolerance concerns than reported CRS or irAEs.
Humans ; Leukocytes, Mononuclear ; Hematopoietic Stem Cell Transplantation/adverse effects* ; Leukemia, Myeloid, Acute/therapy* ; Unrelated Donors ; Granulocyte Colony-Stimulating Factor ; Graft vs Host Disease

Objective To identify the relationship between nephritis activity, autophagy and inflammation in patients with SLE. Methods Western blot analysis was used to detect the expression of microtubule-associated protein 1 light chain 3 (LC3) and P62 in peripheral blood mononuclear cells (PBMCs) of SLE patients with lupus nephritis and non-lupus nephritis patients. Tumor necrosis factor α (TNF-α) and interferon γ (IFN-γ) in the serum of SLE patients were determined by ELISA. The correlation between LC3II/LC3I ratio and SLE disease activity score (SLEDAI), urinary protein, TNF-α and IFN-γ levels was analyzed by Pearson method. Results The expression of LC3 was increased and P62 was decreased in SLE patients. TNF-α and IFN-γ were increased in the serum of SLE patients. LC3II/LC3I ratio was positively correlated with SLEDAI (r=0.4560), 24 hour urine protein (r=0.3753), IFN-γ (r=0.5685), but had no correlation with TNF-α (r=0.04 683). Conclusion Autophagy is found in PBMCs of SLE, and the autophagy is correlated with renal damage and inflammation in patients with lupus nephritis.
Humans ; Tumor Necrosis Factor-alpha/metabolism* ; Leukocytes, Mononuclear/metabolism* ; Autophagy-Related Proteins/metabolism* ; Lupus Nephritis/urine* ; Kidney ; Interferon-gamma/metabolism* ; Inflammation/metabolism* ; Lupus Erythematosus, Systemic/metabolism*