Specific Cell Surface Antigens Research Articles

Next-generation cell-penetrating antibodies for tumor targeting and RAD51 inhibition.

Monoclonal antibody therapies for cancer have demonstrated extraordinary clinical success in recent years. However, these strategies are thus far mostly limited to specific cell surface antigens, even though many disease targets are found intracellularly. Here we report studies on the humanization of a full-length, nucleic acid binding, monoclonal lupus-derived autoantibody, 3E10, which exhibits a novel mechanism of cell penetration and tumor specific targeting. Comparing humanized variants of 3E10, we demonstrate that cell uptake depends on the nucleoside transporter ENT2, and that faster cell uptake and superior in vivo tumor targeting are associated with higher affinity nucleic acid binding. We show that one human variant retains the ability of the parental 3E10 to bind RAD51, serving as a synthetically lethal inhibitor of homology-directed repair in vitro. These results provide the basis for the rational design of a novel antibody platform for therapeutic tumor targeting with high specificity following systemic administration.

Regenerative Potential of Dental Pulp Stem Cells in Response to a Bioceramic Dental Sealer and Photobiomodulation: An In Vitro Study.

This study aims to assess the synergistic effect of utilizing a bioceramic sealer, NeoPutty, with photobiomodulation (PBM) on dental pulp stem cells (DPSCs) for odontogenesis. Dental pulp stem cells were collected from 10 premolars extracted from healthy individuals. Dental pulp stem cells were characterized using an inverted-phase microscope to detect cell shape and flow cytometry to detect stem cell-specific surface antigens. Three experimental groups were examined: the NP group, the PBM group, and the combined NP and PBM group. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) experiment was conducted to assess the viability of DPSCs. The odontogenic differentiation potential was analyzed using Alizarin red staining, RT-qPCR analysis of odontogenic genes DMP-1, DSPP, and alkaline phosphatase (ALP), and western blot analysis for detecting BMP-2 and RUNX-2 protein expression. An analysis of variance (ANOVA) followed by a post hoc t-test was employed to examine and compare the mean values of the results. The study showed a notable rise in cell viability when NP and PBM were used together. Odontogenic gene expression and the protein expression of BMP-2 and RUNX-2 were notably increased in the combined group. The combined effect of NeoPutty and PBM was significant in enhancing the odontogenic differentiation capability of DPSCs. The synergistic effect of NeoPutty and PBM produced the most positive effect on the cytocompatibility and odontogenic differentiation potential of DPSCs. Creating innovative regenerative treatments to efficiently and durably repair injured dental tissues. How to cite this article: Alshawkani HA, Mansy M, Al Ankily M, et al. Regenerative Potential of Dental Pulp Stem Cells in Response to a Bioceramic Dental Sealer and Photobiomodulation: An In Vitro Study. J Contemp Dent Pract 2024;25(4):313-319.

Targeted desialylation and cytolysis of tumour cells by fusing a sialidase to a bispecific T-cell engager.

Bispecific T-cell engagers (BiTEs) bring together tumour cells and cytotoxic T cells by binding to specific cell-surface tumour antigens and T-cell receptors, and have been clinically successful for the treatment of B-cell malignancies. Here we show that a BiTE-sialidase fusion protein enhances the susceptibility of solid tumours to BiTE-mediated cytolysis of tumour cells via targeted desialylation-that is, the removal of terminal sialic acid residues on glycans-at the BiTE-induced T-cell-tumour-cell interface. In xenograft and syngeneic mouse models of leukaemia and of melanoma and breast cancer, and compared with the parental BiTE molecules, targeted desialylation via the BiTE-sialidase fusion proteins enhanced the formation of immunological synapses, T-cell activation and T-cell-mediated tumour-cell cytolysis in the presence of the target antigen. The targeted desialylation of tumour cells may enhance the potency of therapies relying on T-cell engagers.

CD22 is a potential target of CAR-NK cell therapy for esophageal squamous cell carcinoma

BackgroundChimeric antigen receptor NK (CAR-NK) cell therapy is one of the most promising immunotherapies. Although it has shown a significant therapeutic effect in hematologic malignancies, few successes have been obtained in solid tumors including esophageal squamous cell carcinoma (ESCC). The major reasons are lack of specific cell surface antigens and complex tumor microenvironment. Here we identify CD22, a well-known tumor surface marker in hematologic malignancies, is expressed in ESCC, possibly serving as a potential target of CAR-NK cell therapy.MethodsThe expression of 13 tumor cell surface antigens used clinically was analyzed in patients from The Cancer Genome Atlas (TCGA) database. Also, mRNA expression were detected in 2 ESCC cell lines and 2 patients samples by qCPR. Then according to Venn diagram, CD22 was selected for further investigation. Following this, the expression of CD22 by immunofluorescence (IF) in ESCC cell lines and by immunohistochemistry (IHC) in 87 cases of human ESCC samples was detected respectively. On the basis of H-score results, the correlation between CD22 expression and clinical parameters was analyzed. As a proof, the efficacy of CD22-targeted CAR-NK cells against ESCC cell lines was performed by a real-time cell analyzer (RTCA) platform.ResultsKYSE-140 and KYSE-150 cell lines displayed surface expression of CD22. IHC showed an 80.46% (70/87) positive rate in ESCC patient samples. Among these, cell membranous expression of CD22 was observed in 27.59% (24/87) patient samples. Through chi-square test, expression of CD22 in ESCC was associated with lymph node metastasis while it was no related to the depth of tumor invasion and clinical stage. Engineered CD22-targeted CAR-NK cells exhibited inhibitory growth capability against ESCC cell lines (p < 0.0001).ConclusionsCD22 is a potential tumor surface antigen capable of being targeted by CAR-NK cells in ESCC. And potential therapeutics for ESCC may be developed based on immune cells expressing anti-CD22 CAR. The study also indicates that CD22 CAR-NK cells could be used in other cancers and more in vivo experiments are needed.

CD38 as a pan-hematologic target for chimeric antigen receptor T cells

AbstractMany hematologic malignancies are not curable with chemotherapy and require novel therapeutic approaches. Chimeric antigen receptor (CAR) T-cell therapy is 1 such approach that involves the transfer of T cells engineered to express CARs for a specific cell-surface antigen. CD38 is a validated tumor antigen in multiple myeloma (MM) and T-cell acute lymphoblastic leukemia (T-ALL) and is also overexpressed in acute myeloid leukemia (AML). Here, we developed human CD38-redirected T cells (CART-38) as a unified approach to treat 3 different hematologic malignancies that occur across the pediatric-to-adult age spectrum. Importantly, CD38 expression on activated T cells did not impair CART-38 cells expansion or in vitro function. In xenografted mice, CART-38 mediated the rejection of AML, T-ALL, and MM cell lines and primary samples and prolonged survival. In a xenograft model of normal human hematopoiesis, CART-38 resulted in the expected reduction of hematopoietic progenitors, which warrants caution and careful monitoring of this potential toxicity when translating this new immunotherapy into the clinic. Deploying CART-38 against multiple CD38-expressing malignancies is significant because it expands the potential for this novel therapy to affect diverse patient populations.

Immuno(T)herapy for age-related diseases.

During the last decade, the stimulation of T-cell function by the blockage of immunosuppressive checkpoints has experienced an outstanding impact in the treatment of cancer. Development of the chimeric antigen receptor T-cell technology has also emerged as a powerful alternative for patients suffering from oncological processes, especially those affected by hematological neoplasms. Recent evidence suggest that the use of immunotherapy could be extended to non-oncological diseases and could be especially relevant for age-associated disorders, opening exciting therapeutic options for a wide range of diseases of the elderly. Here we comment on the emergence of T-cell-based immunotherapies as feasible approaches that could revolutionize the future of GeroScience.

Neomorphic DNA-binding enables tumor-specific therapeutic gene expression in fusion-addicted childhood sarcoma

Chimeric fusion transcription factors are oncogenic hallmarks of several devastating cancer entities including pediatric sarcomas, such as Ewing sarcoma (EwS) and alveolar rhabdomyosarcoma (ARMS). Despite their exquisite specificity, these driver oncogenes have been considered largely undruggable due to their lack of enzymatic activity.Here, we show in the EwS model that – capitalizing on neomorphic DNA-binding preferences – the addiction to the respective fusion transcription factor EWSR1-FLI1 can be leveraged to express therapeutic genes.We genetically engineered a de novo enhancer-based, synthetic and highly potent expression cassette that can elicit EWSR1-FLI1-dependent expression of a therapeutic payload as evidenced by episomal and CRISPR-edited genomic reporter assays. Combining in silico screens and immunohistochemistry, we identified GPR64 as a highly specific cell surface antigen for targeted transduction strategies in EwS. Functional experiments demonstrated that anti-GPR64-pseudotyped lentivirus harboring our expression cassette can specifically transduce EwS cells to promote the expression of viral thymidine kinase sensitizing EwS for treatment to otherwise relatively non-toxic (Val)ganciclovir and leading to strong anti-tumorigenic, but no adverse effects in vivo. Further, we prove that similar vector designs can be applied in PAX3-FOXO1-driven ARMS, and to express immunomodulatory cytokines, such as IL-15 and XCL1, in tumor entities typically considered to be immunologically ‘cold’.Collectively, these results generated in pediatric sarcomas indicate that exploiting, rather than suppressing, the neomorphic functions of chimeric transcription factors may open inroads to innovative and personalized therapies, and that our highly versatile approach may be translatable to other cancers addicted to oncogenic transcription factors with unique DNA-binding properties.

Chimeric Antigen Receptor Design and Efficacy in Ovarian Cancer Treatment.

Our increased understanding of tumour biology gained over the last few years has led to the development of targeted molecular therapies, e.g., vascular endothelial growth factor A (VEGF-A) antagonists, poly[ADP-ribose] polymerase 1 (PARP1) inhibitors in hereditary breast and ovarian cancer syndrome (BRCA1 and BRCA2 mutants), increasing survival and improving the quality of life. However, the majority of ovarian cancer (OC) patients still do not have access to targeted molecular therapies that would be capable of controlling their disease, especially resistant or relapsed. Chimeric antigen receptors (CARs) are recombinant receptor constructs located on T lymphocytes or other immune cells that change its specificity and functions. Therefore, in a search for a successful solid tumour therapy using CARs the specific cell surface antigens identification is crucial. Numerous in vitro and in vivo studies, as well as studies on humans, prove that targeting overexpressed molecules, such as mucin 16 (MUC16), annexin 2 (ANXA2), receptor tyrosine-protein kinase erbB-2 (HER2/neu) causes high tumour cells toxicity and decreased tumour burden. CARs are well tolerated, side effects are minimal and they inhibit disease progression. However, as OC is heterogenic in its nature with high mutation diversity and overexpression of different receptors, there is a need to consider an individual approach to treat this type of cancer. In this publication, we would like to present the history and status of therapies involving the CAR T cells in treatment of OC tumours, suggest potential T cell-intrinsic determinants of response and resistance as well as present extrinsic factors impacting the success of this approach.

Comparison of stem cell markers on Gingival mesenchymal stem cells among diabetic and healthy individuals. An Ex Vivo Pilot study

Aim: Diabetes mellitus (DM), being a risk factor for periodontal disease, affects various cellular functions, and it plays an important role in periodontal regeneration. However, the effect of hyperglycemia on Gingival mesenchymal stem cells (GMSCs) is unclear. We aim at investigating the effect of hyperglycemia on stem cell markers of GMSCs compared with normoglycemic conditions. Materials and Methods: An ex vivo pilot study was conducted by obtaining primary gingival tissues from subjects. Subjects from the outpatient department of periodontology were randomly selected according to the criteria. Three subjects with an HbA1c of >6.5 were selected as the test group, and three subjects with an HbA1c <6 served as controls. The tissue was enzymatically digested in 0.5 mg/mL collagenase (Sigma-Aldrich) and cultured in Knockout Dulbecco‘s Modified Eagles Medium (DMEM - KO medium, Life Technologies). MSC-like cells isolated were examined under a microscope and investigated for specific cell surface antigens CD73, CD90, CD105, CD34, CD45, HLA ABC, and HLA DR by using flow cytometry. Data were analyzed by a two-tailed non-parametric Mann–Whitney U test using SPS software. P < 0.05 was considered statistically significant. Results: The immunophenotype characterization in both test and control exhibited positive expression of CD73 (94.95%,95.93%), CD90 (98.05%, 88.53%), CD105 (73.97%, 73.88%), and HLA ABC (98.83%,98.16%) and negative expression of CD34 (0.02%,0.10%), CD45(0.57%,1.72%), and HLA DR (0.64%, 2.57%). Statistical analysis by the nonparametric Mann–Whitney U test did not reveal any statistically significant difference in the expression. Conclusion: GMSCs from the hyperglycemic environment retained their stem cell characteristics by positive expression of CD73, CD90, CD105, and HLA ABC, and negative expression of CD34, CD45, and HLA DR.

Single and Dual Targeting Chimeric Antigen Receptor T-Cell Therapy in Acute Myeloid Leukemia

BACKGROUND: Discovery of chimeric antigen receptors (CARs) specific for tumour-associated antigens are emerging to be an effective form of immunotherapy for cancer treatment in recent years. However, the lack of a compelling acute myeloid leukemia (AML)-specific cell surface antigen and the safety concerns for myeloid-directed CAR T therapies causing prolonged myeloablation/aplasia which necessitate bone marrow transplantation make it challenging to develop CARTs for AML. In spite of these challenges, the high relapse rate of the disease i.e. 43% and 18% patients never attaining clinical remission (CR) with front-line induction treatments highlight an unmet need for developing improved CAR T vectors with enhanced specificity towards leukemic blasts in refractory/resistant cases with poor cytogenetics. Therefore, we aim to develop improved CAR T vectors for AML that produce safe and consistent responses in patients with high-risk disease. Herein, we demonstrate the in-vitro data for (a) efficacy of a second-generation CAR expressing six single-chain variable fragments (scFv) with different affinities for CD123 [interleukin three receptor alpha (IL3RA; CD123), a molecule over expressed on AML blasts and leukemic stem cells (LSC)] and (b) evaluate the cytotoxic effects of a dual targeting CARCD123/CD33 (against CD123 and CD33; an important myeloid marker specifically expressed on bulk AML disease) to enhance specificity towards leukemic cells therefore reducing "on-target off-organ effects". METHOD: Six lentiviral vectors with CAR against CD123 were constructed i.e. two high affinity (4nM kD &amp; 4nM kD with a point mutation resulting in amino acid change K136Q), two moderate (56nM kD &amp; 56nM kD with mutation at A105G) and two low affinity vectors (101nM kD &amp; 101nM kD with mutation at V24G). To improve the specificity of the single targeting CARCD123, the high affinity (4nM kD, K136Q) vector was utilized to generate two dual targeting (CARCD123/CD33) constructs containing the activation domain (CD3ζ) directed against CD33 and the costimulatory domain (either CD28 or 41BB) directed against CD123. All constructs were transduced (MOI 1:5) into peripheral blood mononuclear cells (PBMCs) from healthy donors or AML patients and their cytotoxicity was examined by flowcytometry on leukemic cell lines; Kg1, U937, K562 [Fig:1a], Ramos wild type (CD19+, CD123-), artificially engineered Ramos cells (transduced by lentiviral vectors with CD123 and/or CD33 cDNA) i.e. Ramos 123 (CD123+), Ramos 33 (CD33+), Ramos 123/33 (CD123+ and CD33+) and AML mononucelar cells (MNCs). RESULTS: Flowcytometric analysis confirmed the expansion of T cells from PBMCs and cytotoxicity of the eight CAR constructs against target cells in in-vitro co-culture assay. High affinity CARCD123 (4nM kD &amp; 4nM kD K136Q) T cells demonstrated enhanced cytotoxicity [Fig 1a] compared to moderate (56nM kD, 56nM kD A105G) CARCD123 in all leukemic cell lines while the low affinity (101nM kD, 101nM kD V24G) vectors had no effect. Efficacy of the high affinity CARCD123 constructs was validated on Kg1 [Fig 1b] and Ramos 123+ target cells by the increasing effector: target ratios (1:2, 1:4 &amp; 1:10). Similar cytotoxic effects were also consistently observed against autologous AML MNCs (target cells) [n=4] and allogenic (effector cells are PBMCs from healthy donors) AML MNCs [Fig 1c] [n=3]. T cell activation was confirmed by ELISA and showed increased IFN-γ (500-2000 fold) and TNF-α (150-200 fold) levels after 24hr co-culture. Furthermore, we also elucidated the exclusive cytotoxicity of the two dual targeting CARCD123/CD33 in Ramos 123+/33+ cells [Fig 1d] with no effect being observed on Ramos 123+, Ramos 33+ and Ramos wild type (123-/33-) cell lines. This confirmed the absence of non-specific targeting, validated the improved specificity of the CARs towards leukemic cells and demonstrated a potential to reduce deleterious "on-target but off organ effects". CONCLUSION: In summary, we illustrate in-vitro data establishing the importance of scFv on CAR T cell cytotoxicity and exemplify for the first time an improved specificity of CARTs by targeting two antigens simultaneously in AML. Future work will involve examining the in-vivo dynamics of CAR CD123 and CAR CD123 CD33 on the hematopoietic system and on disease pathogenesis with an aim to proceed to phase I clinical trial. Figure 1 Disclosures Mufti: BMS, Novartis: Research Funding; Abbvie, Novartis: Consultancy.

ALPPL2 Is a Highly Specific and Targetable Tumor Cell Surface Antigen.

Identification of tumor-specific cell surface antigens has proven challenging, as the vast majority of tumor-associated antigens are also expressed in normal tissues. In mesothelioma, we identified a highly specific tumor cell surface antigen that can be targeted for therapy development. Mesothelioma is caused by malignant transformation of the mesothelium, is incurable, and can be categorized into three histologic subtypes: epithelioid, biphasic, and sarcomatoid. To identity novel mesothelioma cell surface antigens with broad subtype coverage and high tissue specificity, we have previously selected phage antibody display libraries on live mesothelioma cells and tissues following counterselection on normal cells and identified a panel of human antibodies that bind all subtypes of mesothelioma, but not normal mesothelium. One of the antibodies, M25, showed high specificity against an antigen we identify here as ALPPL2. IHC on normal human tissues found that ALPPL2 is expressed only on placental trophoblasts, but not on any other normal tissues. This significant tissue specificity and broad tumor type coverage suggest that ALPPL2 could be an excellent cell surface target for therapeutic development against mesothelioma. To evaluate therapeutic potential of ALPPL2 targeting, an ALPPL2-targeted antibody-drug conjugate was developed and demonstrated potent and specific tumor killing in vitro and in vivo against both epithelioid and sarcomatoid mesothelioma. Thus, ALPPL2 belongs to a rare class of cell surface antigens classified as truly tumor specific and is well suited for therapy development against ALPPL2-expressing tumors. SIGNIFICANCE: These findings identify ALPP2 as a true tumor-specific cell surface antigen whose tissue specificity enables the development of novel therapies.

ЭКСПРЕССИЯ ПОВЕРХНОСТНОГО АНТИГЕНА BRUCELLA ABORTUS ОМР16 В РАСТЕНИИ NICOTIANA BENTHAMIANA

Brucellosis is one of the most contagious and infectious diseases with high incidence rates of cattle and humans in Kazakhstan. Using modern biotechnology techniques to develop vaccines that are reliable and affordable for farmers is an alternative solution to the problem. Plant viruses are often used as a vector for obtaining the expression of antigens of the pathogen. The grape virus A (BAB) is widely used among plant viruses. Brucella membrane proteins are the main objects of this research for futher development of vaccines or diagnostic texts against brucellosis, Membrane proteins (OMPs) are cell specific surface antigens that are immunogenic. OMPs are ideal candidates for the production of recombinant brucellosis vaccines. The object of the study was the outer membrane protein (Omp16), which plays an important role in the suppression of TNF-α production in macrophages. In this study, molecular cloning and analysis of the expression of the Omp16 gene, which was used to express the recombinant protein in plants, was carried out. We selected brucella from the vaccine strain of Brucella abortus 19, and the plant Nicotiana benthamiana, as the subjects for our research, since they widely used for the production of recombinant proteins, and they both appropriate for molecular genetic research. A viral vector was constructed to express the brucellosis antigen Omp16 in Nicotiana benthamiana plants. Nineteen explants were used for the regeneration of transgenic plants. As a result of this studies, the introduced gene of Omp16 was under the subgenomic promoter control of the ORF4 and was successfully expressed while maintaining the efficiency of expression in transgenic plants. The efficiency of viral vectors was evaluated at the level of transcription during expression of the protein Omp16 with viral proteins. The entire leaf blade was infiltrated; the density of Agrobacteria was 0.7. We were able to obtained transgenic plants Nicotiana benthamiana carrying the gene of capsid protein BAB, and the expression of the membrane antigen Omp16 in the viral vector was achieved by replacing the ORF4 with the Omp16 gene. The development of transgenic plants was carried out using agrobacterial transformation.

CAR T cell therapies for patients with multiple myeloma.

Despite several therapeutic advances over the past decade, multiple myeloma (MM) remains largely incurable, indicating a need for new treatment approaches. Chimeric antigen receptor (CAR) T cell therapy works by mechanisms distinct from those of other MM therapies and involves the modification of patient or donor T cells to target specific cell-surface antigens. B cell maturation antigen (BCMA) is expressed only on plasma cells, a small subset of B cells and MM cells, which makes it a suitable target antigen for such therapies. At the time of writing, data from >20 clinical trials involving anti-BCMA CAR T cells have demonstrated that patients with relapsed and/or refractory MM can achieve objective responses. These early investigations have been instrumental in demonstrating short-term safety and efficacy; however, most patients do not have disease remission lasting >18 months. Attempts to reduce or delay the onset of relapsed disease are underway and include identifying additional CAR T cell target antigens and methods of enhancing BCMA expression on MM cells. Engineering CAR T cells to enhance both the activity and safety of treatment continues to be a promising avenue for improvement. In this Review we summarize data from clinical trials that have been carried out to date, describe novel antigens that could be targeted in the future, and highlight potential future innovations that could enhance the efficacy and/or reduce the toxicities associated with CAR T cell therapies.

Antibody-Drug Conjugates in Thoracic Malignancies: Clinical Trials Reveal Both Promise and Challenges.

Thoracic malignancies are the main cause of cancer-related deaths worldwide. The need to develop new therapies is therefore urgent. The recognition of new potential therapeutic targets in thoracic malignancies has prompted the development of a number of antibody-drug conjugates. This new class of potent anticancer agents is supposed to more specifically and directly target the tumor while limiting toxicity for healthy tissues by delivering a toxic payload to tumor cells that are recognized by the presence of specific cell surface antigens. Progress in the development of antibody-drug conjugates over the last decade has been significant, with several promising advances. Unfortunately, many failures have also been encountered, often because of unexpectedly severe toxicities that contradicted the assumed mechanism of action, and major challenges remain. Various techniques to reduce the toxicities associated with antibody-drug conjugates are being studied, and the panorama of antibody-drug conjugates in clinical stages continues to increase and evolve. Current efforts in the conjugation and linker chemistries could result in the successful construction of clinically effective compounds. The future clinical development of antibody-drug conjugates could benefit from the identification of such payloads that can provide more safe and effective derivatives. Highly potent compounds with reasonable aqueous solubility, non-immunogenic profile, and stability in storage and the bloodstream should be important aspects of research into cytotoxic payloads.

Tetrandrine Induces HL-60 Cell Differentiation

To investigate the differentiation of acute promyelocytic leukemia (APL) cells induced by Tetrandrine targeting MUC1. HL-60 cells at logarithmic growth phase were choosen as object of reaserch and were divided into four groups: control, ATRA, Tetrandrine and ATRA+Tetrandrine group. Cell morphologic changes in each group were observed by microscopy. The change of cell differentiation ability was analyzed by nitro-blue tetrazolium (NBT) reduction test. The expression of cell surface differentiation antigen CD11b was measured by flow cytometry. The expression of MUC1 protein was detected by Western blot. The differentiation of HL-60 cell could be induced by Tetrandrine. The NBT reduction-positive rate of ATRA+Tetrandrine group was significantly higher than that in ATRA group and Tetrandrine group (P<0.05). The percentage of CD11b positive cells in ATRA+Tetrandrine group(43.62％±1.38％) was significantly higher than that in Tetrandrine group(15.25％±2.11％), ATRA group (28.84％±7.53％) and control group(8.16％±1.01％) (P<0.05). The content of MUC1 protein in Tetrandrine group was significantly lower than that in control group and ATRA group (P<0.05). Tetrandrine and ATRA can synergize to promote the differentiation and maturation of HL-60 cells, and the mechanism may be related with MUC1 expression.

Post-rituximab immunoglobulin M (IgM) hypogammaglobulinemia.

Rituximab is a B cell depleting monoclonal antibody that targets the B cell-specific cell surface antigen CD20 and is currently used to treat several autoimmune diseases. The elimination of mature CD20-positive B lymphocytes committed to differentiate into autoantibody-producing plasma cells is considered to be the major effect of rituximab, that makes it a beneficial biological agent in treating autoimmune diseases. Hypogammaglobulinemia has been reported after rituximab therapy in patients with lymphoma and rheumatoid arthritis. Similar data are scarce for other autoimmune diseases. Low immunoglobulin G (IgG) or hypogammaglobulinemia has attracted the most attention because of its significant role in protective immunity. However, the incidence and clinical implications of low immunoglobulin M (IgM) or hypogammaglobulinemia have not been studied in detail. This review will focus on the frequency and the clinical concerns of low IgM levels that result as a consequence of the administration of rituximab. The etiopathogenic mechanisms underlying post-rituximab IgM hypogammaglobulinemia and its implications are presented. The long-term consequences, if any, are not known or documented. Multiple factors may be involved in whether IgG or IgM decreases secondary to rituximab therapy. It is possible that the autoimmune disease itself may be one of the important factors. The dose, frequency and number of infusions appear to be important variables. Post-rituximab therapy immunoglobulin levels return to normal. During this process. IgM levels take a longer time to return to normal levels when compared to IgG or other immunoglobulins. IgM deficiency persists after B cell repopulation to normal levels has occurred. Laboratory animals and humans deficient in IgM can have multiple infections. Specific pharmacologic agents or biologic therapy that address and resolve IgM deficiency are currently unavailable. If the clinical situation so warrants, then prophylactic antibiotics may be indicated and perhaps helpful. Research in this iatrogenic phenomenon will provide a better understanding of not only the biology of IgM, but also the factor(s) that control its production and regulation, besides its influence if any, on rituximab therapy.

Preliminary evaluation and mechanism of adipose-derived stem cell transplantation from allogenic diabetic rats in the treatment of diabetic rat wounds

Preliminary evaluation and mechanism of adipose-derived stem cell transplantation from allogenic diabetic rats in the treatment of diabetic rat wounds

Adenanthin Induces Differentiation of Acute Promyelocytic Leukemia Cells by Targeting Peroxiredoxin III

To investigate the differentiation of acute promyelocytic leukemia (APL) cells induced by adenosine targeting Prx III. HL-60 cells were divided into four groups: control group, all-trans retinoic acid (ATRA) group, adenanthin group and ATRA+adenanthin group. Cell morphologic changes were observed under optical microscope. The influence of adenanthin on the differentiation of HL-60 was observed by nitro blue tetrazolium chloride (NBT) test. Cell surface differentiation antigens CD11b expression was measured by flow cytometry. The protein expression of Prx III was detected by immunohistochemical assay. Adenanthin could induce the differentiation of HL-60 cells; the NBT reduction positive rate in ATRA+adenanthin group was significantly higher than that in ATRA group and adenanthin group (P＜0.05). The percentage of CD11b positive cells in ATRA+adenanthin group (43.62％±1.38％) was higher than that in adenanthin group (28.15％±1.78％), ATRA group (36.72％±1.33％) and control group (7.99％±1.78％) (P＜0. 05). The content of Prx Ⅲ protein in adenanthin group was significantly higher than that in control group and ATRA group (P＜0.05). Adenanthin and ATRA have a synergistic effect on the differentiation and maturation of HL-60 cells, and its mechanism may be related with regulation of Prx III expression.

CD39&lt;sup&gt;+&lt;/sup&gt; EXPRESSION BY REGULATORY T CELLS IN PULMONARY SARCOIDOSIS AND LOFGREN’S SYNDROME

Sarcoidosis is a disorder of unknown etiology characterized by development of necrosis-free epithelioid cell granulomas in various tissues. There are two main phenotypes of pulmonary sarcoidosis (PS): Lofgren’s syndrome (LS) is an acute form with favorable outcome, while non-Lofgren’s syndrome (nLS) is a chronic type of disease that can lead to pulmonary fibrosis in 20% of cases.Our study was aimed at investigating changes in the main cell-surface differentiation antigens on peripheral blood regulatory T cells (Tregs) from the patients with first diagnosed PS without treatment (LS, n = 11) and nLS (n = 46) compared to healthy volunteers (HC, n = 26).These indexes might be used as immunological markers for predicting severity of this disorder. Flow cytometry analysis of peripheral blood cell samples demonstrated that the nLS patients had decreased relative numbers of CD3+ cells vs healthy controls, as well as diminished CD3+CD4+ cells vs HC and LS patients. Furthermore, the relative and absolute Treg numbers were also decreased in nLS group vs HC (2.83% (2.47; 3.36) vs 3.33% (2.79; 3.84), p = 0.021), and 37 (29; 52) cells vs 50 (42; 65), p = 0.004, respectively) per one microliter of peripheral blood. Relative number of CD39-positive Тregs in chronic vs acute sarcoidosis patients was associated with 51.02% (38.20; 61.62) vs 48.64% (41.46; 63.72) that was significantly (p &lt; 0.001 and p = 0.007, respectively) higher than in HC (39.52% (11.55; 46.34). We have found that “naïve” (CD45R0-CD62L+) Тregs did not significantly differ in percentage of CD39- and CD73-positive cells in all the groups tested. Moreover, CD45R0+CD62L+ Тregs in LS and nLS patients contained significantly more CD39-positive cells (69.66% (61.92; 79.34) and 67.62% (61.92; 79.34), respectively, compared to 47.55% (15.74; 65.32) in HC (p &lt; 0.001 and p = 0.004, respectively). In case of CD45R0 + CD62LTregs able to exit from the circulation and migrate to the site of inflammation, an increased percentage of CD39-positive subset was noted only in patients with chronic sarcoidosis and HC (61.79% (55.12; 73.09) and 57.27% (16.03; 66.98), p = 0.006). Enhanced CD39 expression on Tregs seems to be related to chronic immune response, so that antigen elimination becomes impossible due to Treg overactivation, as shown in patients with sarcoidosis and some other chronic autoimmune and infectious disorders.

Targeting advanced urothelial carcinoma-developing strategies.

Advanced urothelial carcinoma is a heterogeneous disease with high burden of morbidity, mortality, and cost. Significant progress has been made in understanding the biology of the disease and the development of immunotherapies and targeted therapies. In this review, we summarize the current and future therapeutic approaches in the management of urothelial carcinoma. Advances in immune checkpoint inhibitors resulted in the Food and Drug Administration (FDA) approvals of atezolizumab in 2016, and pembrolizumab, avelumab, durvalumab, and nivolumab in 2017 for the treatment of advanced urothelial carcinoma. More recently, development of inhibitors targeting the fibroblast growth factor receptor genetic alterations and antibody-drug conjugates targeting specific cell surface antigens (trop2, nectin4, and SLITRK6) resulted in several FDA breakthrough designations for urothelial carcinoma. The development of novel therapies targeting the immune and molecular pathways of advanced urothelial carcinoma is promising for the improvement of outcomes in this lethal disease. Ongoing efforts are poised to optimize therapeutic options in the post-chemotherapy arena. In the era of precision medicine, the future of urothelial carcinoma lies in using less cytotoxic chemotherapy, more targeted therapy and immunotherapy, and possibly a combination of these therapeutic approaches.