CD4 Molecule Research Articles

The murine CD94/NKG2 ligand, Qa-1b, is a high-affinity, functional ligand for the CD8αα homodimer

The immune co-receptor CD8 molecule (CD8) has two subunits, CD8α and CD8β, which can assemble into homo or heterodimers. Nonclassical (class-Ib) major histocompatibility complex (MHC) molecules (MHC-Ibs) have recently been identified as ligands for the CD8αα homodimer. This was demonstrated by the observation that histocompatibility 2, Q region locus 10 (H2-Q10) is a high-affinity ligand for CD8αα which also binds the MHC-Ib molecule H2-TL. This suggests that MHC-Ib proteins may be an extended source of CD8αα ligands. Expression of H2-T3/TL and H2-Q10 is restricted to the small intestine and liver, respectively, yet CD8αα-containing lymphocytes are present more broadly. Therefore, here we sought to determine whether murine CD8αα binds only to tissue-specific MHC-Ib molecules or also to ubiquitously expressed MHC-Ib molecules. Using recombinant proteins and surface plasmon resonance-based binding assays, we show that the MHC-Ib family furnishes multiple binding partners for murine CD8αα, including H2-T22 and the CD94/NKG2-A/B-activating NK receptor (NKG2) ligand Qa-1b We also demonstrate a hierarchy among MHC-Ib proteins with respect to CD8αα binding, in which Qa-1b > H2-Q10 > TL. Finally, we provide evidence that Qa-1b is a functional ligand for CD8αα, distinguishing it from its human homologue MHC class I antigen E (HLA-E). These findings provide additional clues as to how CD8αα-expressing cells are controlled in different tissues. They also highlight an unexpected immunological divergence of Qa-1b/HLA-E function, indicating the need for more robust studies of murine MHC-Ib proteins as models for human disease.

Molecular analysis of lymphoid tissue from rhesus macaque rhadinovirus-infected monkeys identifies alterations in host genes associated with oncogenesis.

Rhesus macaque (RM) rhadinovirus (RRV) is a simian gamma-2 herpesvirus closely related to human Kaposi’s sarcoma-associated herpesvirus (KSHV). RRV is associated with the development of diseases in simian immunodeficiency virus (SIV) co-infected RM that resemble KSHV-associated pathologies observed in HIV-infected humans, including B cell lymphoproliferative disorders (LPD) and lymphoma. Importantly, how de novo KSHV infection affects the expression of host genes in humans, and how these alterations in gene expression affect viral replication, latency, and disease is unknown. The utility of the RRV/RM infection model provides a novel approach to address these questions in vivo, and utilizing the RRV bacterial artificial chromosome (BAC) system, the effects of specific viral genes on host gene expression patterns can also be explored. To gain insight into the effects of RRV infection on global host gene expression patterns in vivo, and to simultaneously assess the contributions of the immune inhibitory viral CD200 (vCD200) molecule to host gene regulation, RNA-seq was performed on pre- and post-infection lymph node (LN) biopsy samples from RM infected with either BAC-derived WT (n = 4) or vCD200 mutant RRV (n = 4). A variety of genes were identified as being altered in LN tissue samples due to RRV infection, including cancer-associated genes activation-induced cytidine deaminase (AICDA), glypican-1 (GPC1), CX3C chemokine receptor 1 (CX3CR1), and Ras dexamethasone-induced 1 (RasD1). Further analyses also indicate that GPC1 may be associated with lymphomagenesis. Finally, comparison of infection groups identified the differential expression of host gene thioredoxin interacting protein (TXNIP), suggesting a possible mechanism by which vCD200 negatively affects RRV viral loads in vivo.

CD22 Expression in B-Cell Acute Lymphoblastic Leukemia: Biological Significance and Implications for Inotuzumab Therapy in Adults.

CD22 is a surface molecule expressed early during the ontogeny of B cells in the bone marrow and spleen, and can be found on B cells isolated from the different lymphoid compartments in humans. CD22 is expressed by most blasts from the majority (60–90%) of B-cell acute lymphoblastic leukemia (B-ALL). Current therapies in adults with newly diagnosed B-ALL are associated with complete remission (CR) rates of 50–90%. However, 30–60% of these patients relapse, and only 25–40% achieve disease-free survival of three years or more. Chemotherapy regimens for patients with refractory/relapsed B-ALL are associated with CR rates ranging from 31% to 44%. Novel immune-targeted therapies, such as blinatumomab and inotuzumab (a humanized anti-CD22 monoclonal antibody conjugated to the cytotoxic antibiotic agent calicheamicin), provide potential means of circumventing chemo-refractory B-ALL cells through novel mechanisms of action. Eighty percent of inotuzumab-treated B-ALL patients may achieve a CR state. This review is focused on the biological and clinical activities of CD22 antibodies in B-ALL, and provides evidence about the potential role played by qualitative and quantitative analysis of the CD22 molecule on individual B-ALL blasts in predicting the depletion of leukemic cells, and, ultimately, leading to better clinical response rates.

Atomistic probing of aptameric binding of CD19 outer membrane domain reveals an "aptamer walking" mechanism.

We propose an integrated structural approach to search potential aptamer molecules for targeting cancer receptor proteins. We used the outer cellular domain of the B-lymphocyte antigen, CD19, as the target for this study. First, using available protein-aptamer structures deposited in the protein data bank as resources, structural annotation was performed to seek the most probable binding aptamer and its potential initial configuration to the CD19 structure. Using this initial structure, molecular dynamics (MD) simulations were performed for adjustment of the aptamer-binding. During this process, we observed an "aptamer walking" mechanism of the binding of the single-stranded RNA-aptamer to CD19: the aptamer molecule gradually adjusts its configurations and shifts toward favorable binding positions. However, the target molecule CD19 maintained a relatively stable conformation during this process. The interface area between the RNA-aptamer and CD19 increased from less than 8 nm2 to over 12 nm2 during a 2-μs MD simulation. Using a stable binding pose as the starting structure, we manually mutated the RNA-aptamer to a DNA-aptamer and found that the interface area was further increased to over 16 nm2 , indicating a stronger affinity compared to the RNA-aptamer. The RNA- and DNA-aptamers and their stable binding-poses to the CD19 molecule may be used as templates in designing potential aptamer molecules that target the B-cell marker molecule CD19 with enhanced specificity and stability.

High Expression of Pd-1 in Circulating Cells of Patients With Advanced Colorectal Cancer Receiving Adjuvant Therapy.

Among all cancer types, colorectal cancer is the third most common in men and the second most common in women globally. Generally, the risk of colorectal cancer increases with age, and colorectal cancer is modulated by various genetic alterations. Alterations in the immune response serve a significant role in the development of colorectal cancer. In primary cancer types, immune cells express a variety of inhibitory molecules that dampen the immune response against tumor cells. Additionally, few reports have demonstrated that classical chemotherapy promotes the immunosuppressive microenvironment in both tissues and immune cells. This study assessed the expression levels of genes using RT-qPCR associated with the immune system, including interferon-γ, programmed death-1, β2-microglobulin, human leukocyte antigen-A, CD3e, CD28 and intracellular adhesion molecule 1, in patients with colorectal cancer, as these genes are known to serve important roles in immune regulation during cancer incidence. Gene expression analysis was performed with the whole blood cells of patients with colorectal cancer and healthy volunteers. Compared with the normal controls, programmed death-1was highly expressed in patients with advanced-stage colorectal cancer. Furthermore, the expression of programmed death-1 was higher in patients receiving adjuvant therapy, which suggests the therapy dampened the immune response against tumor cells. The results of the present study indicate that classical adjuvant therapies, which are currently used for patients with colorectal cancer, should be modulated, and a combination of classical therapy with anti-programmed death-1 antibody should be conducted for improved management of patients with colorectal cancer.

Synovial fluid CD69+CD8+ T cells with tissue-resident phenotype mediate perforin-dependent citrullination in rheumatoid arthritis.

ObjectivesAlthough the importance of tissue‐resident memory T (TRM) cells in organ‐specific chronic inflammation has been recognised, little is known about their role in rheumatoid arthritis (RA). Here, we examined the characteristics of synovial fluid CD8+ T cells that express canonical TRM markers CD69 and CD103, and their role in the pathogenesis of RA.MethodsSynovial fluid mononuclear cells (SFMCs) were obtained from patients with RA. Flow cytometric analysis of surface markers and cytotoxic molecules of CD8+ T cells was performed. TCR repertoire of CD8+ T cells was analysed by TCRVβ CDR3 sequencing. Citrullination with the formation of neutrophil extracellular trap (NET) was evaluated by immunofluorescence staining.ResultsThe frequency of CD8+ T cells was increased in SFMCs, and these CD8+ T cells were primarily comprised of CD45RA‐ memory T cells expressing CD69 and/or CD103. CD69+CD8+ T cells exhibited TRM phenotypes, including upregulation of CXCR6, CD49a and CD101, and downregulation of S1PR1 and KLF2. TCR repertoire analysis showed that these cells were an oligoclonally expanded population with increased expression of cytotoxic molecules. The treatment of neutrophils with supernatant from IL‐15‐stimulated CD69+CD8+ T cells induced perforin‐mediated histone citrullination and NET formation irrespective of their CD103 expression. The frequency of perforin‐expressing cells among CD69+CD8+ T cells in SFMCs was significantly higher in patients with anti‐citrullinated protein antibody (ACPA) than in those without ACPA.ConclusionCD69+CD8+ T cells in the SFMCs of RA patients exhibit TRM‐like features. These cells may participate in the pathogenesis of RA via perforin‐mediated citrullination.

CD40 ligand dictated signaling bias

T cells are pivotal for innate and adaptive immune response. On, T cell a co-stimulatory molecule CD40 ligand is present that binds to the CD40 receptor. CD40L a type II membrane protein, consists of 261 amino acids belong to a member of the TNF-family. There are 193 amino acids present at the extracellular domain of CD40 ligand requires basic amino acid residue K143, R203, R207 for receptor binding, however, the CD40 molecule requires acidic amino acid residue D84, E114, E117 for activation of the different signaling cascade. Binding of CD40L with CD40 receptors activate JAK-STAT signaling, inflammatory cytokines, chemokines along with various downstream transcription factor molecules. As it is well studied, deficiency in CD40 ligand leads to an autoimmune disorder called Hyper X-linked IgM syndrome. So studies on HXIM syndrome revealed that an extracellular domain of CD40 ligand is cardinal for receptor binding. Depending on binding strength, signaling skew will be decided. Stronger will activate p38 MAPK (anti-parasitic in nature) by inducing IL-12 however, weaker will activate ERK-1/2 (pro-parasitic in nature) by inducing IL-10. The specific binding of the receptor is necessary to decode the message encoded by binding stimulation. Therefore, CD40 ligand wild type residues bind with CD40 site-directed mutagenized with different amino acids. These mutant CD40 ligands upon binding with CD40 reveal a better insight into the nature of host-pathogen interaction, inflammatory cytokines, chemokines and signaling molecules. Therefore, we can assume CD40 ligand mutants have a role in anti-leishmanial function.

CXCR2 specific endocytosis of immunomodulatory peptide LL-37 in human monocytes and formation of LL-37 positive large vesicles in differentiated monoosteophils

Immunomodulatory peptide cathelicidin/LL-37 induces human monocyte differentiation into a novel bone repair cell, the monoosteophil. We now demonstrate that LL-37 is endocytosed by monocytes over a period of 6 days producing large (10 × 2 μm), specialized LL-37 and integrin α3 positive vesicles. CXCR2, a membrane receptor previously associated with the binding of LL-37 to neutrophils, was co-endocytosed with LL-37 where both markers remained within the cytosol over a 16 h observation period. Endocytosis of LL-37 was mediated by a clathrin- and cavoelin/lipid raft-dependent pathway into early Rab5+ endosomes expressing APPL1 and EEA1. From 4 to 16 h, LL-37 vesicles co-localized with the Golgi, mitochondria, and to a lesser extent lysosomes and ER. By day 6, LL-37 was associated with large (>10 μm) vesicles, adjacent to Golgi, mitochondria, ER and lysosomes. LL-37 co-stained with integrin α3, tetraspanin CD9, GPI-linked CD59 and costimulatory molecule CD276 (B7-H3) in these vesicles. Continuous tracking of LL-37 with its associated vesicles over 6 days indicates that LL-37 is an extremely stable, membrane-associated peptide that plays a critical role in the differentiation of monocytes into monoosteophils.

135 Strategies for transfection of bovine mesenchymal stem cells with pBC1-anti-CD3 vector

Cells from different origins behave differently regarding the incorporation of exogenous genetic material and the formation of transgenic cells. In this context, the objective of this study was to verify the potential of transfection of bovine mesenchymal stem cells from Wharton's jelly and adipose tissue, comparing two transfection protocols, using Lipofectamine LTX and Plus or Xfect reagents, with the integration of humanized anti-CD3. Skin fibroblasts were used as a control group. Humanized anti-CD3 is a monoclonal antibody that interacts with the CD3 molecule of the T-cell receptor, leading to the suppression of T-cells. This antibody is considered an option in the treatment of human autoimmune diseases and against the rejection of transplanted organs. Humanized anti-CD3 was used in this work for the production of bovine transgenic cells that, in the future, will be used in the development of bioreactor animals. In all steps of this study, cell types were cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal calf serum (FCS) and antibiotics, in an incubator at 39°C with 5% CO2 in air with saturated humidity. All cells were plated at 5×105 into 24-well culture dishes and co-transfected with vector pBC1-anti-CD3-IRES-FEO and pEF-NEO-GFP using Lipofectamine LTX with reagent Plus or Xfect. Forty-eight hours after transfection, neomycin was added in each treatment and cells were cultured for 2 weeks. Treated cells were submitted to fluorescence microscopy, flow cytometry, and PCR evaluations. Wharton's jelly cells were sensitive to treatments and started necrosis. In the flow cytometry assay, the median fluorescence was higher in adipocytes than in fibroblasts, for both the Xfect reagent (20.057±1.620.7 and 10.601±702.86, respectively, P<0.05) and for LTX (19.590±113.84 and 10.518±442.65 respectively, P<0.05). These results, associated with the evaluation of epifluorescence, demonstrated that adipocytes presented a better response to transfection than did other cells, independent of the kit used. Performing PCR on co-transfected adipocytes and fibroblasts demonstrated the presence of anti-CD3, making this approach feasible in future experiments. Southern blotting analysis is being performed to confirm DNA integration. Financial support was provided by Fundação de Amparo à Pesquisa do Distrito Federal (FAPDF); Embrapa MP1.

Effect of Down-Regulating the CD59 by RNAi Lentivirus on the Expression of Acute T-lineage Leukemia Jurkat Cell Line

To analyze the effect of down-regulating the CD59 gene expression by RNAi lentivirus as vector on Jurkat cell line of acute T-lineage leukemia. The expression of CD59 in Jurkat cell line of acute T-line leukemia was induced to decrease by RNAi lentivirus as vector. The transfection of RNA lentivirus and the localization of CD59 molecule were analyzed by laser confocal technique. The relative expression of CD59 gene in blank control, negative control and RNAi lentivirus transfected group was detected by real-time fluorescence quantitative PCR, and the enzyme-linked immunosorbent assay was used to detect the expression of TNF-β and IL-3 in supernatants of cultured cells in 3 groups. The expression levels of apoptosis-related molecules including Caspase-3, Survivin, BCL-2 and BCL-2-associated X protein (BAX) were measured by Western blot. The transfection efficiency for Jurkat cells was higher than 90%. CD59 was mainly located on the cell membrane. Compared with the blank control group and the negative control group, the expression level of CD59 mRNA and protein in the RNAi lentivirus transfected group significantly decreased (P<0.05). Compared with the blank control group and the negative control group, the expression of TNF-β and IL-3 in the RNAi lentivirus transfected group were significantly higher and lower (P<0.05) respectively. The expression levels of Survivin and BCL-2 in the RNAi lentivirus transfected group were significantly lower than those in the blank control group and the negative control group, while the expression levels of Caspase-3 and BAX in the RNAi lentivirus transfected group were significantly higher than those in the blank control group and the negative control group (P< 0.05). The down-regulation of CD59 gene expression induced by RNAi lenti-virus can decrease the expression of proliferation and differentiation-promoting molecule such as IL-3 and increase the expression of TNF-related factor in Jurkat cell line of acute T-lineage leukemia, which also can increase the expression of apoptosis-related proteins such as Caspase-3 and BAX, and decrease the expression of anti-apoptosis-related proteins such as Survivin and BCL-2.

Effect of Down-Regulating the CD59 by RNAi Lentivirus on the Expression of Acute T-lineage Leukemia Jurkat Cell Line

To analyze the effect of down-regulating the CD59 gene expression by RNAi lentivirus as vector on Jurkat cell line of acute T-lineage leukemia. The expression of CD59 in Jurkat cell line of acute T-line leukemia was induced to decrease by RNAi lentivirus as vector. The transfection of RNA lentivirus and the localization of CD59 molecule were analyzed by laser confocal technique. The relative expression of CD59 gene in blank control, negative control and RNAi lentivirus transfected group was detected by real-time fluorescence quantitative PCR, and the enzyme-linked immunosorbent assay was used to detect the expression of TNF-β and IL-3 in supernatants of cultured cells in 3 groups. The expression levels of apoptosis-related molecules including Caspase-3, Survivin, BCL-2 and BCL-2-associated X protein (BAX) were measured by Western blot. The transfection efficiency for Jurkat cells was higher than 90%. CD59 was mainly located on the cell membrane. Compared with the blank control group and the negative control group, the expression level of CD59 mRNA and protein in the RNAi lentivirus transfected group significantly decreased (P<0.05). Compared with the blank control group and the negative control group, the expression of TNF-β and IL-3 in the RNAi lentivirus transfected group were significantly higher and lower (P<0.05) respectively. The expression levels of Survivin and BCL-2 in the RNAi lentivirus transfected group were significantly lower than those in the blank control group and the negative control group, while the expression levels of Caspase-3 and BAX in the RNAi lentivirus transfected group were significantly higher than those in the blank control group and the negative control group (P< 0.05). The down-regulation of CD59 gene expression induced by RNAi lenti-virus can decrease the expression of proliferation and differentiation-promoting molecule such as IL-3 and increase the expression of TNF-related factor in Jurkat cell line of acute T-lineage leukemia, which also can increase the expression of apoptosis-related proteins such as Caspase-3 and BAX, and decrease the expression of anti-apoptosis-related proteins such as Survivin and BCL-2.

Allogeneic Chimeric Antigen Receptor-Invariant Natural Killer T Cells Exert Both Direct and Indirect Antitumor Effects through Host CD8 T Cell Cross-Priming

Chimeric antigen receptor (CAR) T cells have shown impressive results in refractory B-cell malignancies. Unfortunately, to date, commercially available cells, as well as most products tested in clinical trials, are autologous CAR T cells whose widespread use is limited by the logistical and financial burdens related to their ad hoc generation. The development of universal allogeneic CAR T cell products to be used off-the-shelf across MHC-barriers has faced major limitations, namely the risk of Graft-versus-Host-Disease (GvHD) induction and the rejection of the administered cells by the host immune system. Invariant Natural Killer-T (iNKT) cells are innate lymphocytes that are deprived of any GvHD induction potential but that display antitumor effects both directly, through the production of cytotoxic effector molecules, and indirectly, through the enhancement of NK and CD8 T cell-mediated immune responses. Preclinical studies using xenogeneic mouse models have demonstrated the feasibility of using iNKT cells as a platform for CAR-based therapies, and two clinical trials are currently ongoing. In order to study the interaction of CD19-specific iNKT CAR cells with the host immune system, we transduced iNKT cells ex vivo expanded from FVB/N mice with a CAR composed of the variable region cloned from the 1D3 hybridoma recognizing murine CD19 linked to a portion of the murine CD28 molecule and to the cytoplasmic region of the murine CD3-ζ molecule. The cytotoxic potential of CD19-iNKT CAR was confirmed in an in vitro cytotoxic assay against the CD19-expressing A20 lymphoma cell line, revealing a strong, dose dependent cytotoxic effect of CD19-CAR iNKT cells. Accordingly, and similarly to what was previously reported in xenogeneic studies, FVB/N (H-2Kq) derived iNKT CAR (2x10e6 cells iv) significantly improved survival of mice after administration to major histocompatibility complex (MHC)-mismatched, immunodeficient BALB/c (H-2Kd) Rag2-/- gamma-chain-/- mice receiving A20 cells (2x10e4 cells iv; Figure 1A) without inducing any signs of GvHD. To test the efficacy of iNKT CAR cells in the presence of host immune cells, we tested the antitumor activity mediated by iNKT CAR against A20 cells in BALB/c mice receiving sublethal irradiation (4.4 Gy), resulting in only a partial and transient lymphopenia. In this model, the antitumor effect of iNKT CAR cells was greatly enhanced, leading to long-term survival of the great majority of treated mice (Figure 1B). Such a difference in iNKT CAR effect between mice that genetically lacked lymphocytes and mice with only partial lymphopenia suggested the participation of host derived lymphocytes in the antitumor effect. To test the hypothesis that host CD8 T cell activation via cross-priming could at least partially mediate the indirect antitumor effect of iNKT CAR cells, we repeated the experiment, employing as recipients BALB/c BATF3-/- mice, in which CD8 T cell cross-priming is impaired as a result of the absence of BATF3-dependent CD103+ CD8a+ dendritic cells that are thought to present antigens through CD1d to the invariant T cell receptor expressed by iNKT cells. Interestingly, the iNKT CAR effect was partially abrogated in A20-receiving BATF3-/- mice as compared to WT mice (Figure 1C), supporting the hypothesis that the impact of iNKT CAR cells is mediated at least partially by the activation of host CD8 T cells via their cross-priming. To formally demonstrate the synergistic effect between allogeneic iNKT CAR and autologous CD8 T cells, we employed an autologous bone marrow transplantation model, co-administering allogeneic iNKT CAR with autologous CD8 T cells at the time of transfer of T-cell-depleted autologous bone marrow cells and A20 lymphoma cells into lethally irradiated (8.8 Gy) BALB/c recipients. Co-administration of allogeneic iNKT CAR and autologous CD8 T cells resulted in a synergistic effect, significantly extending animal survival (Figure 1D) compared to mice receiving no treatment, as well as to mice receiving either allogeneic iNKT or autologous CD8 T cells alone. Collectively, these results represent the first demonstration of an immune adjuvant effect exerted by an allogeneic CAR cell product toward the autologous immune system of the host, suggesting that the effect of the administered cells would last longer than the physical persistence of the allogeneic cells after they will be rejected by the host immune system. Figure 1 Disclosures Mackall: Obsidian: Research Funding; Lyell: Consultancy, Equity Ownership, Other: Founder, Research Funding; Nektar: Other: Scientific Advisory Board; PACT: Other: Scientific Advisory Board; Bryologyx: Other: Scientific Advisory Board; Vor: Other: Scientific Advisory Board; Roche: Other: Scientific Advisory Board; Adaptimmune LLC: Other: Scientific Advisory Board; Glaxo-Smith-Kline: Other: Scientific Advisory Board; Allogene: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Apricity Health: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Unum Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

Multicolor Immunophenotyping of Candidate Leukemic Stem Cell Markers in CD34+CD38- Chronic Myeloid Leukemia Stem Cells

Introduction: Detection of leukemic stem cells (LSCs) may represent a new potential prognostic parameter in chronic myeloid leukemia (CML) and a tool for minimal residual disease monitoring in combination with standard qPCR method. To date CD26 is studied as a most specific marker for CML LSC detection. Several other candidate LSC markers have been reported, such as IL1-RAP, CD25 and CD93, however a side-by-side testing of their specificity is lacking. Recently, we have identified CD69 molecule to be overexpressed in CD34+CD38-CD26+ cells, which makes this antigen another candidate marker for LSC. Aim: To compare the surface expression of LSC markers CD69, CD26, CD25, CD56, IL1-RAP, CD56, CD93 in bulk CD34+CD38- population at diagnosis using a multicolor phenotypization assay Methods: In total, 44 patients were analyzed at diagnosis of chronic phase CML before administration of any treatment. Fresh (n=38) or cryopreserved (n=6) leukocytes obtained by erythrolysis were stained with CD45, CD34, CD38, CD25, CD26, CD56, CD69, CD93, IL1-RAP antibodies and 7-AAD for selection of live cells. Analysis was performed on FACSAria Fusion (BD Biosciences). Acquisition of live mononuclear cells ranged from 2×104 to 2.5×106. Results: Expression of candidate LSC markers CD26, CD25, CD56, IL1-RAP, CD56, CD93 was analyzed in BM of 35 patients who carried at least 30 CD34+CD38- cells. Median percentage of marker positive cells was 34% for IL1-RAP, 31% for CD25, 23% for CD26, 16% for CD56 and 2% for CD93, from the parent CD34+CD38- population. Next we analyzed the overlap and combination for the three best markers - IL1-RAP, CD25 and CD26. The 3-combination (defined as IL1-RAP or CD25 or CD26 expression) identified 40% of CD34+CD38- positive cells, which was more than any of the markers alone. Expression of the three markers showed good overlap and ruled out mutually exclusive expression of the markers. This was demonstrated by median difference of 0.4% of CD34+CD38- cells (range: 0-18%) and a correlation coefficient r2=0.9914, when comparing the 3-combination and the best performing marker in each patient. In contrast, in 12/35 (34%) of patients, one of the three markers failed to identify at least half of the cells positive for another marker. In 21/35 patients, we also analyzed the expression of CD69 in the CD34+CD38- compartment. The CD69 showed similar performance as the 3-combination of CD26, CD25, and IL1-RAP, 59% vs 54% positive cells, respectively. We observed excellent overlap between CD69 and 3-combination expression in individual patients with median difference of 0% of CD34+CD38- cells (range 0-15%) and correlation coefficient r2=0.9890. Furthermore, we compared marker positivity in BM vs PB in 19 paired samples. Both, sample types showed similar frequency of CD34+CD38- cells (5×10-3 in BM, and 2×10-3 for PB), but PB carried higher percentage of LSCs identified by the 3-combination - median 76 vs 52% cells. Conclusions: We show an overlap in surface expression of three previously reported CML LSC markers - IL1-RAP, CD25 and CD26. Nevertheless, a combination of these markers can detect more positive cells than any of the markers alone. Moreover, we demonstrate that CD69 identifies the same cells within the CD34+CD38- compartment as the combination of three above mentioned markers, which makes CD69 the best candidate for routine CML LSC quantification. Disclosures Mayer: AOP Orphan Pharmaceuticals AG: Research Funding.

Dendrimers as a Novel Carrier in Anti-HIV Therapy

The present treatments for HIV transfection include chemical agents and gene therapies. Although many chemical drugs, peptides and genes have been developed for HIV inhibition, a variety of non-ignorable drawbacks limited the efficiency of these materials. Dendrimers has ability to carrier of antiviral drugs due to some properties such as mono-dispersity, defined structure, amenability for functionalization using diverse ligands and its low-nanometer size. In this review, we discuss the application of dendrimers as both therapeutic agents and non-viral vectors of chemical agents and genes for HIV treatment. In one way, dendrimers with functional end groups combine with the gp120 of HIV and CD4 molecule of host cell to suppress the attachment of HIV to the host cell. In another way, dendrimers are also able to transfer chemical drugs and genes into the host cells, which increase the anti-HIV activity of these materials. Dendrimers as therapeutic tools provide a potential treatment for HIV infection.&#x0D; Keywords: Dendrimers, Drug release, Drug targeting, gp120, CD4, Antiviral drug

Effect of thermal spring water on human dendritic cell inflammatory response.

BackgroundHydrotherapy appears as a valuable therapeutic tool in the management of patients suffering from chronic skin inflammatory diseases. Nevertheless, the underlying immune mechanisms of these beneficial effects remain poorly understood. To better understand the biological effects of thermal spring water on the immune system, we investigated the effects of Avène thermal spring water (ASW) on dendritic cells as key cells participating in the control of the immune response.MethodsDendritic cells (DCs) were generated from human monocytes and matured with LPS in ASW-based culture medium or in dexamethasone supplemented culture medium as an anti-inflammatory treatment. The phenotypes and abilities of these DCs to produce cytokines and induce allogeneic T cell response was next assessed.ResultsWe showed that ASW modulated the differentiation of monocytes into DCs and impacted the DC maturation upon LPS priming. We observed a reduction of the CD83, CD86, CD1a and HLA-DR molecule expression and a decrease of IL-12 and IL-23 production whereas IL-10 production was increased. LPS-primed DCs generated in presence of ASW exhibited a reduced capacity to induce naive CD4+ T cell proliferation and IFN-γ and IL-17 production.ConclusionOur study showed that ASW is endowed with an immunomodulatory potential. ASW limits the DC stimulatory capacity of Th1 and Th17 cell responses by impairing their maturation, IL-12 and IL-23 production and accessory cell function.

Development of novel monoclonal antibodies with specific binding affinity for denatured human CD26 in formalin-fixed paraffin-embedded and decalcified specimens.

A 110-kDa type II transmembrane glycoprotein with dipeptidyl peptidase IV (DPPIV) activity in its extracellular region, CD26 has a multitude of biological functions and plays an important role in the regulation of inflammatory responses and tumor biology. Our work has focused on CD26 as a novel therapeutic target for various tumors and immune disorders, and we have recently developed a humanized anti-CD26 monoclonal antibody (mAb), YS110, which has promising safety profile and clinical activity in patients with malignant pleural mesothelioma. The development of an anti-human CD26 mAb that can clearly and reliably detect the denatured CD26 molecule in formalin-fixed paraffin-embedded (FFPE) tissues in the clinical setting is therefore of the utmost importance. To develop novel anti-CD26 mAbs capable of binding to denatured CD26, we immunized mice with urea-treated CD26 protein. Hybridoma supernatants were screened for specific reactivity with human CD26 by immunostaining through the use of a set of FFPE human CD26-positive or negative tumor cell lines. This screening method enables us to develop novel anti-human CD26 mAbs suitable for immunohistochemical staining of CD26 in FFPE non-tumor and tumor tissue sections with reliable clarity and intensity. Specifically, these mAbs display strong binding affinity to denatured human CD26 rather than undenatured human CD26, and are capable of detecting denatured human CD26 in decalcified specimens. These novel anti-CD26 mAbs are potentially useful for the analysis of CD26 expression in cancer patients with bony metastasis, and may help decide the appropriateness of YS110 therapy for future cancer patients.

PS1359 DYSREGULATED MICRORNA EXPRESSION IN CIRCULATING PLASMA CELLS IN MULTIPLE MYELOMA

Background:MicroRNAs (miRNAs) are short non‐coding RNA molecules that are involved in many physiological and pathological processes. Multiple myeloma (MM) is the second most common hematological malignancy of plasma cells (PCs). These cells are dependent on the BM microenvironment. However, a subclone of these cells can escape from the bone marrow (BM) either infiltrating soft tissues (extramedullary disease, EM) or escaping to peripheral blood (PB)(as so‐called circulating plasma cells, cPCs). In both cases, loss of BM dependence is a negative prognostic marker for MM patients. IF more than 20% of cPCs are found in PB, the disease is reclassified as plasma cell leukemia (PCL).The importance of miRNA in the pathogenesis of MM has been demonstrated by several studies. Thus, we hypothesize that miRNA dysregulation is involved in the BM escape of PCs.Aims:The aim of this work was to analyze different expression of miRNA between BM PCs samples of EM and MM patients compared to cPCs. Furthermore, the expression of cell surface molecules of cPC was analyzed by flow cytometry.Methods:Using next generation sequencing (NGS), 36 BM PCs from MM patients, 9 BM PCs from EM patients and 17 cPCs samples were analyzed (from MM and PCL patients). 16 paired samples (PB and BM) and 1 sample of PB were analyzed using flow cytometry. For identification of PC/cPC, CD38 and CD138 markers were used. The combination of CD19, CD20, CD27, CD56, CD81, CD117, CD200, CD44 and cytoplasmic nestin markers allows to identify and distinguish between abnormal and normal PCs.Results:NGS analysis showed 2335 different miRNAs that were present in analyzed samples; 578 miRNAs were in at least 30 samples and had more than 1 read per million, were included in subsequent analysis. Out of these miRNA, there are 5 miRNAs (p &lt; 0.000001) that are significantly dysregulated between cPCs and BM PCs from EM patients. Furthermore, there are 7 miRNAs (p &lt; 0.0000000001) significantly dysregulated in cPCs in comparison to BM PCs from MM patients.The flow cytometry analysis showed that median amount of cPCs was 2.63% (0.69–68.7%). The BM infiltration of PCs was 26.75% (10.7–69.9%). Expression of CD19, CD56 and CD20 markers was determined for all 17 cPCs samples. The CD56 molecule was expressed in 75% (12/17), the CD19 molecule expressed in 11.8% (2/17), the CD20 molecule was expressed only in 5.9% (1/17) of all samples. For samples with more than 2% of cPCs (6/16), a more detailed analysis of the cPCs phenotype was performed: CD28 was present in 2/6, CD27 was not present, CD117 in 1/6, CD81 in 2/6, CD44 in 6/6, CD200 in 5/6 and cytoplasmic nestin was negative in all cases. In the BM (16 samples), CD19 was expressed in 2/16, CD20 in 1/16, CD56 in 12/16, CD27 in 2/16, CD28 in 3/13, CD117 in 5/16, CD44 in 12/14, CD200 in 9/13, cytoplasmic nestin in 6/14.Summary/Conclusion:Using NGS, we showed that they are differentially expressed miRNA between MM BM PCs and EM BM PCs and cPCs. Based on flow cytometric analysis, we showed that phenotypic profile of cPCs correlated with the finding in the BM.imageThis work was supported by AZV 17–29343A and AZV 18–003‐00203.

Molecular Responses in THP-1 Macrophage-Like Cells Exposed to Diverse Nanoparticles.

In the body, engineered nanoparticles (NPs) may be recognized and processed by immune cells, among which macrophages play a crucial role. We evaluated the effects of selected NPs [NM-100 (TiO2), NM-110 (ZnO), NM-200 (SiO2), and NM-300 K (Ag)] on THP-1 macrophage-like cells. The cells were exposed to subcytotoxic concentrations of NPs (1–25 µg/mL) and the expression of immunologically relevant genes (VCAM1, TNFA, CXCL8, ICAM1, CD86, CD192, and IL1B) was analyzed by RT-qPCR. The expression of selected cytokines, growth factors and surface molecules was assessed by flow cytometry or ELISA. Generation of reactive oxygen species and induction of DNA breaks were also analyzed. Exposure to diverse NPs caused substantially different molecular responses. No significant effects were detected for NM-100 treatment. NM-200 induced production of IL-8, a potent attractor and activator of neutrophils, growth factors (VEGF and IGF-1) and superoxide. NM-110 triggered a proinflammatory response, characterized by the activation of transcription factor NF-κB, an enhanced production of proinflammatory cytokines (TNF-α) and chemokines (IL-8). Furthermore, the expression of cell adhesion molecules VCAM-1 and ICAM-1 and hepatocyte growth factor (HGF), as well as superoxide production and DNA breaks, were affected. NM-300 K enhanced IL-8 production and induced DNA breaks, however, it decreased the expression of chemokine receptor (CCR2) and CD86 molecule, indicating potential immunosuppressive activity. The toxicity of ZnO and Ag NPs was probably caused by their intracellular dissolution, as indicated by transmission electron microscopy imaging. The observed effects in macrophages might further influence both innate and adaptive immune responses by promoting neutrophil recruitment via IL-8 release and enhancing the adhesion and stimulation of T cells by VCAM-1 and ICAM-1 expression.

New Insights on the Adjuvant Properties of the Leishmania infantum Eukaryotic Initiation Factor.

Vaccination is the most effective tool against infectious diseases. Subunit vaccines are safer compared to live-attenuated vaccines but are less immunogenic and need to be delivered with an adjuvant. Adjuvants are essential for enhancing vaccine potency by improving humoral and cell-mediated immune responses. Only a limited number of adjuvants are licensed for human vaccines, and their mode of action is still not clear. Leishmania eukaryotic initiation factor (LeIF) has been described having a dual role, as a natural adjuvant and as an antigen that possesses advantageous immunomodulatory properties. In this study, we assessed the adjuvant properties of recombinant Leishmania infantum eukaryotic initiation factor (LieIF) through in vitro and in vivo assays. LieIF was intraperitoneally administered in combination with the protein antigen ovalbumin (OVA), and the widely used alum was used as a reference adjuvant. Our in vitro studies using J774A.1 macrophages showed that LieIF induced stimulatory effects as demonstrated by the enhanced surface expression of CD80 and CD86 co-stimulatory molecules and the induced production of the immune mediators NO and MIP-1α. Additionally, LieIF co-administration with OVA in an in vivo murine model induced a proinflammatory environment as demonstrated by the elevated expression of TNF-α, IL-1β, and NF-κB2 genes in peritoneal exudate cells (PEC). Furthermore, PEC derived from OVA-LieIF-immunized mice exhibited elevated expression of CD80 molecule and production of NO and MIP-1α in culture supernatants. Moreover, LieIF administration in the peritoneum of mice resulted in the recruitment of neutrophils and monocytes at 24 h post-injection. Also, we showed that this immunopotentiating effect of LieIF did not depend on the induction of uric acid danger signal. These findings suggest the potential use of LieIF as adjuvant in new vaccine formulations against different infectious diseases.

Endothelial Dysfunction Marker Variation in Young Adults with Chronic Apical Periodontitis before and after Endodontic Treatment

IntroductionCardiovascular diseases are the leading cause of mortality worldwide. Apical periodontitis (AP) has been associated with an increased risk of cardiovascular diseases. A correlation has been shown between chronic AP and endothelial dysfunction (ED), but there is no evidence to indicate ED improves after endodontic treatment in patients with periapical lesions. The aim of this study was to investigate vascular and molecular markers of early ED before and after root canal treatment in young adults with chronic AP. MethodsTwenty control subjects and 21 patients with AP were assessed at baseline. The AP patients were also evaluated 2 and 12 months post-treatment. Endothelial flow reserve was assessed via an endothelial function test, and enzyme-linked immunosorbent assays were used to evaluate plasma levels of proinflammatory cytokines interleukin (IL)-1, IL-6, and tumor necrosis factor alpha; vasoconstrictor ED marker endothelin (ET)-1; circulating endothelial adhesion markers intercellular adhesion molecule 1 (ICAM-1)/CD54 and soluble vascular cellular adhesion molecule (sVCAM)-1/CD106; soluble CD14; and the endothelial leukocyte adhesion molecule (E-selectin). ResultsAP was associated with increased serum levels of ET-1, ICAM-1, E-selectin, IL-1, and sCD14, suggesting early vascular ED, with no macroscopic evidence of a reduction in endothelial flow reserve. Root canal treatment ameliorated inflammation and early ED, lowering plasma levels of IL-1, sCD14, ET-1, ICAM-1/CD54, and E-selectin to those of control subjects. ConclusionsOur findings suggest that AP may drive early vascular ED and that the endodontic therapy of AP ameliorates early ED.