Normal Peripheral Blood Mononuclear Cells Research Articles

Reduced Tolerogenic Program Death-Ligand 1-Expressing Conventional Type 1 Dendritic Cells Are Associated with Rapid Decline in Chronic Obstructive Pulmonary Disease

Background: Chronic obstructive pulmonary disease (COPD) is characterized, at least in part, by autoimmunity through amplified T helper 1 and 17 (Th1 and Th17) immune responses. The loss of immune tolerance controlled by programmed death-ligand 1 (PD-L1) may contribute to this. Objectives: We studied the tolerogenic role of PD-L1+ dendritic cells (DCs) and their subtypes in relation to specific T cell immunity and the clinical phenotypes of COPD. Methods: We used flow cytometry to analyze PD-L1 expression by the DCs and their subtypes in the peripheral blood mononuclear cells (PBMCs) from normal participants and those with COPD. T cell proliferation and the signature cytokines of T cell subtypes stimulated with elastin as autoantigens were measured using flow cytometry and enzyme-linked immunosorbent assays (ELISA), respectively. Measurement and main results: A total of 83 participants were enrolled (normal, n = 29; COPD, n = 54). A reduced PD-L1+ conventional dendritic cell 1 (cDC1) ratio in the PBMCs of the patients with COPD was shown (13.7 ± 13.7%, p = 0.03). The decrease in the PD-L1+ cDC1 ratio was associated with a rapid decline in COPD (p = 0.02) and correlated with the CD4+ T cells (r = −0.33, p = 0.02). This is supported by the NCBI GEO database accession number GSE56766, the researchers of which found that the gene expressions of PD-L1 and CD4, but not CD8 were negatively correlated from PBMC in COPD patients (r = −0.43, p = 0.002). Functionally, the PD-L1 blockade enhanced CD4+ T cell proliferation stimulated by CD3/elastin (31.2 ± 22.3%, p = 0.04) and interleukin (IL)-17A production stimulated by both CD3 (156.3 ± 54.7, p = 0.03) and CD3/elastin (148 ± 64.9, p = 0.03) from the normal PBMCs. The PD-L1 blockade failed to increase IL-17A production in the cDC1-depleted PBMCs. By contrast, there was no significant change in interferon (IFN)-γ, IL-4, or IL-10 after the PD-L1 blockade. Again, these findings were supported by the NCBI GEO database accession number GSE56766, the researchers of which found that only the expression of RORC, a master transcription factor driving the Th17 cells, was significantly negatively correlated to PD-L1 (r = −0.33, p = 0.02). Conclusions: Circulating PD-L1+ cDC1 was reduced in the patients with COPD, and the tolerogenic role was suppressed with susceptibility to self-antigens and linked to rapid decline caused by Th17-skewed chronic inflammation.

ARTS and small-molecule ARTS mimetics upregulate p53 levels by promoting the degradation of XIAP

Mutations resulting in decreased activity of p53 tumor suppressor protein promote tumorigenesis. P53 protein levels are tightly regulated through the Ubiquitin Proteasome System (UPS). Several E3 ligases were shown to regulate p53 stability, including MDM2. Here we report that the ubiquitin E3 ligase XIAP (X-linked Inhibitors of Apoptosis) is a direct ligase for p53 and describe a novel approach for modulating the levels of p53 by targeting the XIAP pathway. Using in vivo (live-cell) and in vitro (cell-free reconstituted system) ubiquitylation assays, we show that the XIAP-antagonist ARTS regulates the levels of p53 by promoting the degradation of XIAP. XIAP directly binds and ubiquitylates p53. In apoptotic cells, ARTS inhibits the ubiquitylation of p53 by antagonizing XIAP. XIAP knockout MEFs express higher p53 protein levels compared to wild-type MEFs. Computational screen for small molecules with high affinity to the ARTS-binding site within XIAP identified a small-molecule ARTS-mimetic, B3. This compound stimulates apoptosis in a wide range of cancer cells but not normal PBMC (Peripheral Blood Mononuclear Cells). Like ARTS, the B3 compound binds to XIAP and promotes its degradation via the UPS. B3 binding to XIAP stabilizes p53 by disrupting its interaction with XIAP. These results reveal a novel mechanism by which ARTS and p53 regulate each other through an amplification loop to promote apoptosis. Finally, these data suggest that targeting the ARTS binding pocket in XIAP can be used to increase p53 levels as a new strategy for developing anti-cancer therapeutics.

Modification of Polyethylene Glycol-Hydroxypropyl Methacrylate Polymeric Micelles Loaded with Curcumin for Cellular Internalization and Cytotoxicity to Wilms Tumor 1-Expressing Myeloblastic Leukemia K562 Cells.

Curcumin loaded in micelles of block copolymers of ω-methoxypoly(ethylene glycol) and N-(2-hydroxypropyl) methacrylamide modified with aliphatic dilactate (CD) or aromatic benzoyl group (CN) were previously reported to inhibit human ovarian carcinoma (OVCAR-3), human colorectal adenocarcinoma (Caco-2), and human lymphoblastic leukemia (Molt-4) cells. Myeloblastic leukemia cells (K562) are prone to drug resistance and differ in both cancer genotype and phenotype from the three mentioned cancer cells. In the present study, CD and CN micelles were prepared and their effects on K562 and normal cells were explored. The obtained CD and CN showed a narrow size distribution with diameters of 63 ± 3 and 50 ± 1 nm, respectively. The curcumin entrapment efficiency of CD and CN was similarly high, above 80% (84 ± 8% and 91 ± 3%). Both CD and CN showed suppression on WT1-expressing K562 and high cell-cycle arrest at the G2/M phase. However, CD showed significantly higher cytotoxicity to K562, with faster cellular uptake and internalization than CN. In addition, CD showed better compatibility with normal red blood cells and peripheral blood mononuclear cells than CN. The promising CD will be further investigated in rodents and possibly in clinical studies for leukemia treatment.

Inhibitory effect of a neddylation blockade on HTLV-1-infected T cells via modulation of NF-κB, AP-1, and Akt signaling

Adult T-cell leukemia (ATL), caused by HTLV-1, is the most lethal hematological malignancy. NEDD8-activating enzyme (NAE) is a component of the NEDD8 conjunction pathway that regulates cullin-RING ubiquitin ligase (CRL) activity. HTLV-1-infected T cells expressed higher levels of NAE catalytic subunit UBA3 than normal peripheral blood mononuclear cells. NAE1 knockdown inhibited proliferation of HTLV-1-infected T cells. The NAE1 inhibitor MLN4924 suppressed neddylation of cullin and inhibited the CRL-mediated turnover of tumor suppressor proteins. MLN4924 inhibited proliferation of HTLV-1-infected T cells by inducing DNA damage, leading to S phase arrest and caspase-dependent apoptosis. S phase arrest was associated with CDK2 and cyclin A downregulation. MLN4924-induced apoptosis was mediated by the upregulation of pro-apoptotic and downregulation of anti-apoptotic proteins. Furthermore, MLN4924 inhibited NF-κB, AP-1, and Akt signaling pathways and activated JNK. Therefore, neddylation inhibition is an attractive strategy for ATL therapy. Our findings support the use of MLN4924 in ATL clinical trials.

The Combination of Oolonghomobisflavan B and Diallyl Disulfide Induces Apoptotic Cell Death via 67-kDa Laminin Receptor/Cyclic Guanosine Monophosphate in Acute Myeloid Leukemia Cells.

Diallyl disulfide (DADS) is a well-known principal functional component derived from garlic (Allium sativum) that has various health benefits. Previously, we identified a 67-kDa laminin receptor, a receptor for oolong tea polyphenol oolonghomobisflavan B (OHBFB). However, its molecular mechanisms still remain to be elucidated. Here, we show that DADS synergistically enhanced the effect of the oolong tea polyphenol oolonghomobisflavan B (OHBFB), which induces apoptosis in acute myeloid leukemia (AML) cancer cells without affecting normal human peripheral blood mononuclear cells (PBMCs). The underlying mechanism of OHBFB-induced anti-AML effects involves the upregulation of the 67-kDa laminin receptor/endothelial nitric oxide synthase/cyclic guanosine monophosphate (cGMP)/protein kinase c delta (PKCδ)/acid sphingomyelinase (ASM)/cleaved caspase-3 signaling pathway. In conclusion, we show that the combination of OHBFB and DADS synergistically induced apoptotic cell death in AML cells through activation of 67LR/cGMP/PKCδ/ASM signaling pathway. Moreover, in this mechanism, we demonstrate DADS may reduce the enzyme activity of phosphodiesterase, which is a negative regulator of cGMP that potentiates OHBFB-induced AML apoptotic cell death without affecting normal PBMCs.

T-cell help in the tumor microenvironment enhances rituximab-mediated NK-cell ADCC

AbstractRituximab (RTX) and other monoclonal antibodies (mAbs) that bind directly to malignant cells are of great clinical value but are not effective for all patients. A major mechanism of action of RTX is antibody-dependent cellular cytotoxicity (ADCC) mediated by natural killer (NK) cells. Prior in vitro studies in our laboratory demonstrated that T cells contribute to maintaining the viability and cytotoxic potential of NK cells activated by anti-CD20–coated target B cells. Here, we conducted studies using a novel mouse model and clinical correlative analysis to assess whether T-cell help contribute to RTX-mediated NK-cell ADCC in the tumor microenvironment (TME) in vivo. A humanized mouse model was developed using Raji lymphoma cells and normal donor peripheral blood mononuclear cells that allows for control of T-cell numbers in the lymphoma TME. In this model, NK-cell viability and CD16 and CD25 expression dropped after RTX in the absence of T cells but increased in the presence of T cells. RTX therapy was more effective when T cells were present and was ineffective when NK cells were depleted. In patients with indolent lymphoma, fine needle aspirates were obtained before and ∼1 week after treatment with a RTX-containing regimen. There was a strong correlation between CD4+ T cells as well as total T cells in the pretherapy TME and an increase in NK-cell CD16 and CD25 expression after RTX. We conclude that T-cell help in the TME enhances RTX-mediated NK-cell viability and ADCC.

Synthesis, anticancer activity, and molecular docking of half-sandwich iron(II) cyclopentadienyl complexes with maleimide and phosphine or phosphite ligands

In these studies, we designed and investigated the potential anticancer activity of five iron(II) cyclopentadienyl complexes bearing different phosphine and phosphite ligands. All complexes were characterized with spectroscopic analysis viz. NMR, FT–IR, ESI–MS, UV–Vis, fluorescence, XRD (for four complexes) and elemental analyses. For biological studies, we used three types of cells—normal peripheral blood mononuclear (PBM) cells, leukemic HL-60 cells and non-small-cell lung cancer A549 cells. We evaluated cell viability and DNA damage after cell incubation with these complexes. We observed that all iron(II) complexes were more cytotoxic for HL-60 cells than for A549 cells. The complex CpFe(CO)(P(OPh)3)(η1-N-maleimidato) 3b was the most cytotoxic with IC50 = 9.09 µM in HL-60 cells, IC50 = 19.16 µM in A549 and IC50 = 5.80 µM in PBM cells. The complex CpFe(CO)(P(Fu)3)(η1-N-maleimidato) 2b was cytotoxic only for both cancer cell lines, with IC50 = 10.03 µM in HL-60 cells and IC50 = 73.54 µM in A549 cells. We also found the genotoxic potential of the complex 2b in both types of cancer cells. However, the complex CpFe(CO)2(η1-N-maleimidato) 1 which we studied previously, was much more genotoxic than complex 2b, especially for A549 cells. The plasmid relaxation assay showed that iron(II) complexes do not induce strand breaks in fully paired ds-DNA. The DNA titration experiment showed no intercalation of complex 2b into DNA. Molecular docking revealed however that complexes CpFe(CO)(PPh3) (η1-N-maleimidato) 2a, 2b, 3b and CpFe(CO)(P(OiPr)3)(η1-N-maleimidato) 3c have the greatest potential to bind to mismatched DNA. Our studies demonstrated that the iron(II) complex 1 and 2b are the most interesting compounds in terms of selective cytotoxic action against cancer cells. However, the cellular mechanism of their anticancer activity requires further research.

Tumor integrin targeted theranostic iron oxide nanoparticles for delivery of caffeic acid phenethyl ester: preparation, characterization, and anti-myeloma activities.

Multiple myeloma (MM) is characterized by the accumulation of malignant plasma cells preferentially in the bone marrow. Currently, emerging chemotherapy drugs with improved biosafety profiles, such as immunomodulatory agents and protease inhibitors, have been used in clinics to treat MM in both initial therapy or maintenance therapy post autologous hematopoietic stem cell transplantation (ASCT). We previously discovered that caffeic acid phenethyl ester (CAPE), a water-insoluble natural compound, inhibited the growth of MM cells by inducing oxidative stress. As part of our continuous effort to pursue a less toxic yet more effective therapeutic approach for MM, the objective of this study is to investigate the potential of CAPE for in vivo applications by using magnetic resonance imaging (MRI)-capable superparamagnetic iron oxide nanoparticles (IONP) as carriers. Cyclo (Arg-Gly-Asp-D-Phe-Cys) (RGD) is conjugated to IONP (RGD-IONP/CAPE) to target the overexpressed αvβ3 integrin on MMcells for receptor-mediated internalization and intracellular delivery of CAPE. A stable loading of CAPE on IONP can be achieved with a loading efficiency of 48.7% ± 3.3% (wt%). The drug-release studies indicate RGD-IONP/CAPE is stable at physiological (pH 7.4) and basic pH (pH 9.5) and subject to release of CAPE at acidic pH (pH 5.5) mimicking the tumor and lysosomal condition. RGD-IONP/CAPE causes cytotoxicity specific to human MM RPMI8226, U266, and NCI-H929 cells, but not to normal peripheral blood mononuclear cells (PBMCs), with IC50s of 7.97 ± 1.39, 16.75 ± 1.62, and 24.38 ± 1.71μM after 72-h treatment, respectively. Apoptosis assays indicate RGD-IONP/CAPE induces apoptosis of RPMI8226 cells through a caspase-9 mediated intrinsic pathway, the same as applying CAPE alone. The apoptogenic effect of RGD-IONP/CAPE was also confirmed on the RPMI8226 cells co-cultured with human bone marrow stromal cells HS-5 in a Transwell model to mimic the MM microenvironment in the bone marrow. In conclusion, we demonstrate that water-insoluble CAPE can be loaded to RGD-IONP to greatly improve the biocompatibility and significantly inhibit the growth of MMcells in vitro through the induction of apoptosis. This study paves the way for investigating the MRI-trackable delivery of CAPE for MM treatment in animal models in the future.

Increased CpG methylation at the CDH1 locus in inflamed ileal mucosa of patients with Crohn disease

BackgroundE-cadherin, a major actor of cell adhesion in the intestinal barrier, is encoded by the CDH1 gene associated with susceptibility to Crohn Disease (CD) and colorectal cancer. Since epigenetic mechanisms are suspected to contribute to the multifactorial pathogenesis of CD, we studied CpG methylation at the CDH1 locus. The methylation of the CpG island (CGI) and of the 1st enhancer, two critical regulatory positions, was quantified in surgical specimens of inflamed ileal mucosa and in peripheral blood mononuclear cells (PBMC) of 21 CD patients. Sixteen patients operated on for a non-inflammatory bowel disease, although not normal controls, provided a macroscopically normal ileal mucosa and PBMC for comparison.ResultsIn ileal mucosa, 19/21 (90%) CD patients vs 8/16 control patients (50%) (p < 0.01) had a methylated CDH1 promoter CGI. In PBMC, CD patients with methylated CGI were 11/21 (52%) vs 7/16 controls (44%), respectively. Methylation in the 1st enhancer of CDH1 was also higher in the CD group for each of the studied CpGs and for their average value (45 ± 17% in CD patients vs 36 ± 17% in controls; p < 0.001). Again, methylation was comparable in PBMC. Methylation of CGI and 1st enhancer were not correlated in mucosa or PBMC.ConclusionsMethylation of several CpGs at the CDH1 locus was increased in the inflamed ileal mucosa, not in the PBMC, of CD patients, suggesting the association of CDH1 methylation with ileal inflammation. Longitudinal studies will explore if this increased methylation is a risk marker for colorectal cancer.

Estimation of Phagocytic activity by normal human peripheral blood mononuclear cells on various oral isolates of Candida species – An in-vitro study

Polymorphonuclear neutrophils (PMN) and mononuclear phagocytes represent an important first line and effector function in control of Candida infections. The aim of the study is to determine the in-vitro phagocytic activity of human peripheral blood mononuclear cells against oral isolates of Candida species and its antifungal susceptibility. The study also evaluates the degree of respiratory burst activity of PBMCs. Phagocytic and lytic indices by PBMCs were determined for Candida spp. The respiratory burst activity was evaluated by nitroblue tetrazolium test. Antifungal disc diffusion susceptibility testing was performed. A total of 100 Candida were isolated belonging to the species C.albicans, C. tropicalis, C.krusei and C.auris. Phagocytic and lytic indices of C.albicans was significant when compared to standard strain of C.albicans. For C.tropicalis and C.krusei phagocytic index was significant while lytic index was not significant when compared to standard strain. The inter species comparison of both the indices was not significant for the clinical isolates of Candida. A significant reduction in phagocytic activity was observed for clinical isolates of Candida spp. but lytic activity was variable when compared to the standard strain of C.albicans.

Exosomes released by environmental pollutant-stimulated Keratinocytes/PBMCs can trigger psoriatic inflammation in recipient cells via the AhR signaling pathway.

Introduction: Exosomes, pivotal in intercellular communication during skin disease pathogenesis, have garnered substantial attention. However, the impact of environmental pollutants, such as benzo[a]pyrene (BaP) and 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), on exosome release amid inflammatory skin diseases remains unexplored. This study addresses this gap by examining the influence of BaP and TCDD on exosome function, specifically focusing on immune-related pathway alterations in normal recipient keratinocytes and peripheral blood mononuclear cells (PBMCs). Methods: HaCaT cells were treated with exosomes from BaP- or TCDD-treated keratinocytes. Proinflammatory cytokines and chemokines, including TNF-α, IL-1β, IL-6, IL-8, CXCL1, and CXCL5, were assessed. The involvement of the p65NF-κB/p38MAPK/ERK signaling pathway in recipient keratinocytes was investigated. Aryl hydrocarbon receptor (AhR) silencing was employed to elucidate its role in mediating the proinflammatory response induced by exosomes from BaP- or TCDD-treated keratinocytes. Results and discussion: Treatment with exosomes from BaP- or TCDD-treated keratinocytes induced a significant increase in proinflammatory cytokines and chemokines in HaCaT cells. The upregulation implicated the p65NF-κB/p38MAPK/ERK signaling pathway. AhR silencing attenuated this response, suggesting a role for AhR in mediating this response. In PBMCs from healthy controls, exosomes from BaP-stimulated PBMCs of psoriatic patients led to increased expression of proinflammatory cytokines and modulation of Th1/Th17 cell distribution via AhR activation. These findings unveil a novel dimension in the interplay between environmental xenobiotic agents (BaP and TCDD) and exosomal functions. The study establishes their influence on psoriatic inflammatory responses, shedding light on the underlying mechanisms mediated through the AhR signaling pathway in recipient keratinocytes and PBMCs.

Janerin, a Sesquiterpene Lactone, Enhances the Apoptosis of Human Leukemia Cell Lines via the Intrinsic Pathway

Background. Still, cancer remains to be one of the main causes of death globally. Sesquiterpene lactones (SLs) appeared to have remarkable pharmacologic properties, particularly as anticancer. This study evaluated the cytotoxicity and apoptogenic potential of Janerin and its underlying mechanism in HL60, THP‐1, and Jurkat leukemia cell lines vs. normal peripheral blood mononuclear cells (PBMCs). Methods. The viability of leukemia and PBMCs following treatment with Janerin (2.5–20 μM) and doxorubicin (2 μM, as the positive control) for 48 h was determined via the resazurin assay. The apoptotic cells were determined by annexin V and propidium iodide test. Also, the genes expressions involved in apoptosis were detected by real‐time PCR. Results. Janerin reduced cell viability in leukemia cells in a dose‐dependent manner with no significant toxicity toward normal PBM cells. Janerin significantly increased apoptosis in leukemia cells after 48 h of treatment. In these cells, the expressions of p21, p53, CASP3, CASP9, and Bax/Bcl2 ratio were significantly elevated, whereas CASP8 remained unchanged (p &lt; 0.01). It was suggested that the intrinsic pathway was the mechanism by which Janerin induced apoptosis in HL60, THP‐1, and Jurkat leukemia cells in a time‐ and dose‐dependent manner. Conclusion. The findings imply that Janerin might be a suitable substitute for doxorubicin in leukemia patients.

In-vitro antimalarial activity of methanolic leaf- and stem-derived extracts from four Annonaceae plants

ObjectivePlants in the Annonaceae family are known for having abundant biologically active secondary metabolites. They have been used in alternative drugs for various diseases in several countries, for instance, the bark of Cananga odorata (Lam.) Hook and Thomson is used for Ophthalmic inflammation and wound healing in Malaysia. Extracts from the leaves and stems of four Annonaceae plants, namely Uvaria longipes (Craib) L.L.Zhou, Y.C.F.Su & R.M.K.Saunders, Dasymaschalon sp., Artabotrys burmanicus A.DC, and Marsypopetalum modestum (Pierre) B.Xue & R.M.K.Saunders were investigated for growth inhibitory activity against blood-stage Plasmodium falciparum growth in vitro and for non-specific cytotoxicity against normal peripheral blood mononuclear cells (PBMCs). Antimalarial activity was assessed by invasion inhibition assay and the percentage of infected red blood cells on blood smears were determined. Cytotoxicity was tested by culturing PBMCs with the extracts, and viabilities were determined by Annexin V/propidium iodide staining.ResultsA. burmanicus stem extract and M. modestum leaf extract were capable of inhibiting growth of P. falciparum when used at 200 µg/mL compared to chloroquine. The extracts at effective concentrations, did not affect the viability of PBMCs. These results support further need for characterization of active compounds from specific Annonaceae plants in order to exploit their components for potential malaria treatment.

Histone Methyltranferase SETD8 Stimulates Proliferation and Anti-Apoptotic Effect in Acute Myeloid Leukemia through Epigenetically Upregulation of CXCR4

Acute myeloid leukemia (AML) is the most common type of leukemia., characterized by the rapid and uncontrolled growth of abnormal cells. Epigenetic modifications control gene expression without affecting its DNA sequence. H4K20me1 is the mono-methylation occurring on lysine 20 of histone H4, acting as an epigenetic mark that promotes gene expression. SETD8 is responsible for catalyzing the mono-methylation of lysine 20 on histone H4. While SETD8's role and mechanisms have been studied in various types of cancer, its function in AML remains unclear. This study is based on the screening of a small molecule compound library, which identified the inhibitor UNC0379 targeting the histone methyltransferase SETD8, showing clear inhibitory effects on three non-M3 AML cell lines. Bioinformatical analysis revealed elevated SETD8 expression in AML patients compared to normal individuals and higher SETD8 expression corresponded with lower overall survival rates (OS). Further investigations using AML cell lines and normal peripheral blood mononuclear cells (PBMCs) demonstrated that SETD8 knockdown or UNC0379 intervention inhibited cell proliferation and increased apoptosis in AML cells, while PBMC cells remained unaffected. In an AML model constructed with C1498 cell injection in C57BL/6J mice, we observed that SETD8 knockdown and treatment with UNC0379 inhibited tumor formation and infiltration. To elucidate the molecular mechanism of SETD8's impact on AML, we conducted transcriptome sequencing on SETD8 knockdown AML cells and found significantly decreased mRNA expression of CXCR4, which was further validated at the protein level. Also, BeatAML and TCGA datasets demonstrated a positive correlation between SETD8 and CXCR4 mRNA expression. These phenomena motivated us to clarify the regulation relationship between SETD8 and CXCR4. CXCR4 is a crucial membrane receptor. After stimulation, it promotes AML cell proliferation and survival. CHIP experiments in SETD8 knockdown cells revealed reduced H4K20me1 enrichment in the CXCR4 promoter region. Subsequent rescue experiments demonstrated that overexpressing CXCR4 or using its corresponding agonist SDF-1alpha in SETD8 knockdown cells moderately restored cell proliferation and reduced apoptosis. In summary, we discovered that SETD8 promotes CXCR4 transcriptional activation through catalyzing the H4K20me1 mark, thereby influencing AML cell proliferation and apoptosis. SETD8 presents a promising therapeutic target through genetic or pharmacological intervention.

AML Immunotherapy Using a Novel Tcrm-Based Bispecific Antibody That Targets a Leader Sequence Peptide Derived from Cathepsin G

Introduction: Myeloid azurophil granules provide a rich source of intracellular leukemia antigens. Cathepsin G (CG) is a serine protease that has higher expression in AML blasts in comparison to normal myeloid progenitors. Based on the unique biology of HLA-A*0201 (HLA-A2), in which presentation of leader sequence (LS)-derived peptides is favored, we focused on the LS-CG-derived peptide CG1 (FLLPTGAEA). LS peptides are naturally processed and loaded on HLA-A2, providing an abundant source of surface peptide/HLA (pHLA) targets. We eluted CG1 from the surface of primary HLA-A2 + AML blasts and AML cell lines, and demonstrated CG1-targeting immunity in leukemia patients following allogeneic stem cell transplant, hence highlighting the potential for CG1 to be a promising immunotherapeutic target in AML. Numerous platforms have been developed to target cell surface pHLA complexes. T cell receptor (TCR) mimic (m) antibodies are immunotherapeutic antibodies that target pHLA, which are the natural ligands for the TCR. TCRm antibodies have been a breakthrough in immunotherapy, as they: (1) target intracellular antigens expressed on HLA; (2) are engineered to have high affinity for HLA; (3) can elicit their cytotoxic effect independent of the TCR; and (4) can be produced in large quantities providing an off-the shelf-product for patient use. Here we report on the engineering, preclinical efficacy, and safety evaluation of a novel CG1-targeting, T cell-engager, bispecific antibody (CG1xCD3e), which incorporates a novel TCRm construct that recognizes cell surface CG1/HLA-A2 complexes. Methods: To generate the CG1/HLA-A2-binding monoclonal antibodies, H2L2 human transgenic mice were immunized with CG1/HLA-A2 monomers subcutaneously. The resulting paired heavy and light chains were cloned from the antigen-sorted memory B cells into the single pcDNA3.1(+) vector with both human (h) immunoglobulin (Ig)G1 and hKappa for subsequent ExpiCHO high-throughput transient expression. Antibody binding was assessed by Bio-Layer Interferometry (BLI) and T2 cellular binding assays. Xencor anti-CD3e scFv and Knobs-in-holes technology was applied for the bispecific antibody engineering for xMab format. In vitro activity of CG1xCD3e and T cell cytokine secretion was confirmed using flow cytometry-based T cell-dependent cellular cytotoxicity (TDCC). The specificity of CG1xCD3e for leukemia was assessed using colony forming unit assays. In vivo efficacy was evaluated in NSG mice engrafted with AML cell lines and treated with CG1xCD3e with normal donor peripheral blood mononuclear cells (ND-PBMC). Results: Using BLI, binding avidity of the CG1xCD3e to CD3-Fc, KD= 7.52 x 10-10 M, and affinity to CG1/HLA-A2, KD= 1.28 x 10-10 M were calculated. Using flow cytometry, we confirmed high affinity binding of CG1xCD3e to CG1/HLA on the CG1- expressing EM2 HLA-A2 + cell line, and also demonstrated binding of CG1xCD3e to CD3 using jurkat T cell line. After co-culturing GFP/Luciferase + HLA-A2 + AML (U937-A2 and ML-2) or CML (EM2) cell lines with ND-PBMC and different concentrations of CG1xCD3e bispecific antibody for 24 or 48 hours, flow cytometry analysis demonstrated highly specific CG1/HLA-A2 dependent killing of AML cells by T cells cultured with CG1xCD3e bispecific antibody, in comparison with control bispecific antibody with a disabled CG1 binding arm. This correlated with both tumor- and bispecific antibody- dependent T cell activation and cytokine secretion. To study the in vivo anti-leukemia activity of CG1xCD3e, we engrafted NSG mice with the HLA-A2 + ML-2 and U937-A2 AML cell lines, and treated mice after tumor engraftment with ND-PBMC (1 x 107 cells) and weekly intraperitoneal injections of CG1xCD3e bispecific antibody (0.01 mg/Kg, 0.05 mg/Kg, and 0.1 mg/Kg) or PBS. Bioluminescence imaging demonstrated that the mice treated with ND-PBMC + CG1xCD3e had significantly lower levels of leukemia burden compared to the mice treated with ND-PBMC alone (Figure 1). Lastly CFU assays using HLA-A2 + normal donor marrow in a semi-solid matrix of methylcellulose in the presence of T cells and either CG1xCD3e bispecific antibody or isotype antibody, confirmed specificity of CG1xCD3e bispecific antibody for leukemia. Conclusion: Our study provides strong pre-clinical evidence supporting the targeting of LS- derived peptides, specifically CG1, in the setting of AML using a novel TCRm-based bispecific antibody.

Synthesis and Antiproliferative Activity of 2,6-Disubstituted Imidazo[4,5-b]pyridines Prepared by Suzuki Cross Coupling.

A series of novel 2,6-diphenyl substituted imidazo[4,5-b]pyridines was designed and synthesized using optimized Suzuki cross coupling to evaluate their biological activity in vitro. The conditions of the Suzuki coupling were evaluated and optimized using a model reaction. To study the influence of the substituents on the biological activity, we prepared N-unsubstituted and N-methyl substituted imidazo[4,5-b]pyridines with different substituents at the para position on the phenyl ring placed at position 6 on the heterocyclic scaffold. Antiproliferative activity was determined on diverse human cancer cell lines, and the selectivity of compounds with promising antiproliferative activity was determined on normal peripheral blood mononuclear cells (PBMC). Pronounced antiproliferative activity was observed for p-hydroxy substituted derivatives 13 and 19, both displaying strong activity against most of the tested cell lines (IC50 1.45-4.25 μM). The unsubstituted N-methyl derivative 19 proved to be the most active derivative. There was a dose-dependent accumulation of G2/M arrested cells in several cancer cell lines after exposure to compound 19, implying a cell cycle-phase-specific mechanism of action. Additionally, the novel series of derivatives was evaluated for antiviral activity against a broad panel of viruses, yet the majority of tested compounds did not show antiviral activity.

Evaluation of Immunomodulatory activity of phytochemicals from Alpinia galanga and Alpinia nigra for potent immunostimulatory agent in chemotherapy

Essential oils are capable of retaining vital medicinal benefits, however, there is a void in the research of biological activities of these oils in complex human disease models which is yet to be validated. For more explorations, we evaluated the medicinal activities of essential oil of A.galanga and A.nigra in order to find potent source of bioactive molecules, cytotoxicity and immuno stimulating activities of the essential oils from the rhizomes. We report immuno stimulating potential of these essential oils. Cytotoxicity of essential oil was evaluated using 3-(4,5-dimethythiazol-2-yl)-2,5- diphenyl tetrazolium bromide (MTT) assay to evaluate the toxicity against normal human peripheral blood mononuclear cells (PBMCs). The immunostimulatory activity on human lymphocytes was evaluated by using Th1 and Th2 cytokine estimations. Analysis of these essential oils through GC-MS revealed high content of 1, 8-cineole in both the oils (28.12% in A.galanga and 24% in A.nigra ). Both the rhizome oils showed significant increase in the number of lymphocytes than that of the control. The oils of A.galanga and A.nigra showed proliferative action on human PBMCs and an increase in both IL-5 and IFN-γ cytokine. As a result, no toxicity was recorded on human PBMCs. Major concentrations of 1,8-cineole and collaborative effects of the total composition of the rhizome oils were possibly accountable for the efficacy of these oils against human PBMCs. These essential oils can be considered as potential source of natural immunostimulatory agent in chemotherapy and also play important role in other immune suppressed diseases.

Microbiota-derived short chain fatty acids in fermented Kidachi Aloe promote antimicrobial, anticancer, and immunomodulatory activities

BackgroundFermented Aloe leaf juice is a commonly used food supplement in Japan. In a previous study, fermentation of A. arborescence juice was performed and the presence of short-chain fatty acids (SCFAs) was confirmed and quantified. Samples were collected before and after the fermentation process to be subjected, in the present study, to DNA extraction, 16S rRNA gene (V3–V4 regions) amplification, and sequencing by the next-generation Illumina MiSeq sequencer. Our work aims to analyze the sequences to assess the bacterial diversity in the juice before and after fermentation, identify the beneficial microbes responsible for the production of SCFAs, and evaluate some of the biological activities of the fermented juice.ResultsData revealed the richness and diversity of the bacterial community in the fermented juice compared to the unfermented control. Relative abundance of bacterial phyla showed that the majority of the microbial community in the test samples corresponded to Pseudomonadota (unfermented; 10.4%, fermented; 76.36%), followed by Bacillota (unfermented; 4.71%, fermented; 17.13%) and then Bacteroidota (unfermented; 0.57%, fermented; 1.64%). For the fermented sample, 84% of Bacillota were lactobacilli. A hierarchically clustered heatmap revealed that Lactobacillus was the most abundant genus in both samples suggesting its involvement in the production of SCFAs.To assess potential health benefits, the anticancer efficacy of the fermented product of A. arborescens was investigated against colorectal cancer (IC50 = 3.5 µg/ml) and liver cancer (IC50 = 6.367 µg/ml) compared to the normal peripheral blood mononuclear cells (PBMCs). Flow cytometric analysis of the cell cycle pattern revealed remarkable population arrest in G0 and G1, however, the highest percentages were mainly in the G1 phase for Hep-G2 (40.1%) and HCT-116 (53.2%) cell lines. This effect was accompanied by early apoptotic profiles of HCT-116 (36.9%) and late apoptosis for Hep-G2 (17.3%). Furthermore, immunomodulatory properties demonstrated a significantly (p < 0.001) reduced percentage of induced TNF-α while enhancing IFN-γ dramatically. For antimicrobial activities, marked broad-spectrum activities were recorded against some bacterial and fungal pathogens (17–37 mm inhibition zone diameter range).ConclusionTherefore, this study affords the basis of bacterial community composition in fermented A. arborescens juice as well as its potential biological benefits.

Lysin (K)-specific demethylase 1 inhibition enhances proteasome inhibitor response and overcomes drug resistance in multiple myeloma

BackgroundMultiple myeloma (MM) is an incurable plasma cell malignancy, accounting for approximately 1% of all cancers. Despite recent advances in the treatment of MM, due to the introduction of proteasome inhibitors (PIs) such as bortezomib (BTZ) and carfilzomib (CFZ), relapses and disease progression remain common. Therefore, a major challenge is the development of novel therapeutic approaches to overcome drug resistance, improve patient outcomes, and broaden PIs applicability to other pathologies.MethodsWe performed genetic and drug screens to identify new synthetic lethal partners to PIs, and validated candidates in PI-sensitive and -resistant MM cells. We also tested best synthetic lethal interactions in other B-cell malignancies, such as mantle cell, Burkitt’s and diffuse large B-cell lymphomas. We evaluated the toxicity of combination treatments in normal peripheral blood mononuclear cells (PBMCs) and bone marrow stromal cells (BMSCs). We confirmed the combo treatment’ synergistic effects ex vivo in primary CD138+ cells from MM patients, and in different MM xenograft models. We exploited RNA-sequencing and Reverse-Phase Protein Arrays (RPPA) to investigate the molecular mechanisms of the synergy.ResultsWe identified lysine (K)-specific demethylase 1 (LSD1) as a top candidate whose inhibition can synergize with CFZ treatment. LSD1 silencing enhanced CFZ sensitivity in both PI-resistant and -sensitive MM cells, resulting in increased tumor cell death. Several LSD1 inhibitors (SP2509, SP2577, and CC-90011) triggered synergistic cytotoxicity in combination with different PIs in MM and other B-cell neoplasms. CFZ/SP2509 treatment exhibited a favorable cytotoxicity profile toward PBMCs and BMSCs. We confirmed the clinical potential of LSD1-proteasome inhibition in primary CD138+ cells of MM patients, and in MM xenograft models, leading to the inhibition of tumor progression. DNA damage response (DDR) and proliferation machinery were the most affected pathways by CFZ/SP2509 combo treatment, responsible for the anti-tumoral effects.ConclusionsThe present study preclinically demonstrated that LSD1 inhibition could provide a valuable strategy to enhance PI sensitivity and overcome drug resistance in MM patients and that this combination might be exploited for the treatment of other B-cell malignancies, thus extending the therapeutic impact of the project.

Regulation of immune response against third-stage Gnathostoma spinigerum larvae by human genes.

Gnathostomiasis is an important zoonosis in tropical areas that is mainly caused by third-stage Gnathostoma spinigerum larvae (G. spinigerum L3). This study aimed to prove whether G. spinigerum L3 produces extracellular vesicles (EVs) and investigate human gene profiles related to the immune response against the larvae. We created an immune cell model using normal human peripheral blood mononuclear cells (PBMCs) co-cultured with the larvae for 1 and 3 days, respectively. The PBMCs were harvested for transcriptome sequencing analysis. The EV ultrastructure was examined in the larvae and the cultured medium. Extracellular vesicle-like particles were observed under the larval teguments and in the pellets in the medium. RNA-seq analysis revealed that 2,847 and 3,118 genes were significantly expressed on days 1 and 3 after culture, respectively. The downregulated genes on day 1 after culture were involved in pro-inflammatory cytokines, the complement system and apoptosis, whereas those on day 3 were involved in T cell-dependent B cell activation and wound healing. Significantly upregulated genes related to cell proliferation, activation and development, as well as cytotoxicity, were observed on day 1, and genes regulating T cell maturation, granulocyte function, nuclear factor-κB and toll-like receptor pathways were predominantly observed on day 3 after culture. G. spinigerum L3 produces EV-like particles and releases them into the excretory-secretory products. Overall, genotypic findings during our 3-day observation revealed that most significant gene expressions were related to T and B cell signalling, driving T helper 2 cells related to chronic infection, immune evasion of the larvae, and the pathogenesis of gnathostomiasis. Further in-depth studies are necessary to clarify gene functions in the pathogenesis and immune evasion mechanisms of the infective larvae.