CD52 as both a marker and an effector molecule of T cells with regulatory action: Identification of novel regulatory T cells

Vδ1 T Cells Integrated in Full-Thickness Skin Equivalents: A Model for the Role of Human Skin-Resident γδT Cells

Vδ1 T cells are a subpopulation of γδT cells found in human dermis. Much less is known regarding their role and function in skin health and disease than regarding the roles of murine skin-resident γδT cells. In this study, we report the successful integration of Vδ1 T cells into long-term fibroblast-derived matrix skin equivalents. We isolated Vδ1 T cells from human blood, where they are rare, and established conditions for the integration and maintenance of the freshly isolated Vδ1 T cells in the skin equivalents. Plated on top of the dermal equivalents, almost all Vδ1 T cells migrated into the dermal matrix where they exerted their influence on both the dermal equivalents and the epithelium. Vδ1 T cells contributed to epidermal differentiation of HaCaT cells as indicated by histology, expression of epidermal differentiation markers, and RNA-sequencing expression profile. When complemented with the carcinoma-derived SCC13 cells instead of HaCaT, our data suggest a role for Vδ1 T cells in slowing growth of the tumor cells, as indicated by reduced stratification and changes in gene expression profiles. Together, we demonstrate the successful establishment of human Vδ1 T cell-competent skin equivalents and skin carcinoma equivalents and provide evidence for molecular and functional consequences of the Vδ1 T cells on their respective environment.

Single cell characterization of blood and expanded regulatory T cells in autoimmune polyendocrine syndrome type 1

Immune tolerance fails in autoimmune polyendocrine syndrome type 1 (APS-1) because of AIRE mutations. We have used single cell transcriptomics to characterize regulatory T cells (Tregs) sorted directly from blood and from in vitro expanded Tregs in APS-1 patients compared to healthy controls. We revealed only CD52 and LTB (down) and TXNIP (up) as consistently differentially expressed genes in the datasets. There were furthermore no large differences of the TCR-repertoire of expanded Tregs between the cohorts, but unique patients showed a more restricted use of specific clonotypes. We also found that in vitro expanded Tregs from APS-1 patients had similar suppressive capacity as controls in co-culture assays, despite expanding faster and having more exhausted cells. Our results suggest that APS-1 patients do not have intrinsic defects in their Treg functionality, and that their Tregs can be expanded ex vivo for potential therapeutic applications.

Heterogeneity of hepatocyte dynamics restores liver architecture after chemical, physical or viral damage

Midlobular hepatocytes are proposed to be the most plastic hepatic cell, providing a reservoir for hepatocyte proliferation during homeostasis and regeneration. However, other mechanisms beyond hyperplasia have been little explored and the contribution of other hepatocyte subpopulations to regeneration has been controversial. Thus, re-examining hepatocyte dynamics during regeneration is critical for cell therapy and treatment of liver diseases. Using a mouse model of hepatocyte- and non-hepatocyte- multicolor lineage tracing, we demonstrate that midlobular hepatocytes also undergo hypertrophy in response to chemical, physical, and viral insults. Our study shows that this subpopulation also combats liver impairment after infection with coronavirus. Furthermore, we demonstrate that pericentral hepatocytes also expand in number and size during the repair process and Galectin-9-CD44 pathway may be critical for driving these processes. Notably, we also identified that transdifferentiation and cell fusion during regeneration after severe injury contribute to recover hepatic function.

Single-cell RNA sequencing reveals peripheral blood mononuclear immune cell landscape associated with operational tolerance in a kidney transplant recipient

Operational tolerance (OT) after kidney transplantation is defined as stable graft acceptance without the need for immunosuppression therapy. However, it is not clear which cellular and molecular pathways are driving tolerance in these patients. In this first-of-its-kind pilot study, we assessed the immune landscape associated with OT using single-cell analyses. Peripheral mononuclear cells from a kidney transplant recipient with OT (Tol), 2 healthy individuals (HC), and a kidney transplant recipient with normal kidney function on standard-of-care immunosuppression (SOC) were evaluated. The immune landscape of the Tol was drastically different from that of SOC and emerged closer to the profile of HC. TCL1A+ naive B cells and LSGAL1+ regulatory T cells (Tregs) were in higher proportions in Tol. We were unable to identify the Treg subcluster in SOC. The ligand-receptor analysis in HC and Tol identified interactions between B cells, and Tregs that enhance the proliferation and suppressive function of Tregs. SOC reported the highest proportion of activated B cells with more cells in the G2M phase. Our single-cell RNA sequencing study identified the mediators of tolerance; however, it emphasizes the requirement of similar investigations on a larger cohort to reaffirm the role of immune cells in tolerance.

mRNA vaccination boosts S-specific T cell memory and promotes expansion of CD45RAint TEMRA-like CD8+ T cells in COVID-19 recovered individuals

SARS-CoV-2 infection and mRNA vaccination both elicit spike (S)-specific T cell responses. To analyze how T cell memory from prior infection influences T cell responses to vaccination, we evaluated functional T cell responses in naive and previously infected vaccine recipients. Pre-vaccine S-specific responses are predictive of subsequent CD8+ T cell vaccine-response magnitudes. Comparing baseline with post-vaccination TCRβ repertoires, we observed large clonotypic expansions correlated with the frequency of spike-specific T cells. Epitope mapping the largest CD8+ T cell responses confirms that an HLA-A∗03:01 epitope was highly immunodominant. Peptide-MHC tetramer staining together with mass cytometry and single-cell sequencing permit detailed phenotyping and clonotypic tracking of these S-specific CD8+ T cells. Our results demonstrate that infection-induced S-specific CD8+ T cell memory plays a significant role in shaping the magnitude and clonal composition of the circulating T cell repertoire after vaccination, with mRNA vaccination promoting CD8+ memory T cells to a TEMRA-like phenotype.

The impact of DAMP-mediated inflammation in severe COVID-19 and related disorders

The host response to SARS-CoV-2, the virus that causes COVID-19, is highly heterogeneous, ranging from mild/asymptomatic to severe. The moderate to severe forms of COVID-19 often require hospitalization, are associated with a high rate of mortality, and appear to be caused by an inappropriately exaggerated inflammatory response to the virus. Emerging data confirm the involvement of both innate and adaptive immune pathways both in protection from SARS-CoV-2, and in driving the pathology of severe COVID-19. In particular, innate immune cells including neutrophils appear to be key players in the inflammation that causes the vicious cycle of damage and inflammation that underlies the symptomatology of severe COVID-19. Several recent studies support a link between damage and inflammation, with damage-associated molecular patterns (DAMPs) playing a key role in the pathology of severe COVID-19. In this review, we put into perspective the role of DAMPs and of components of the DAMP-signaling cascade, including Siglecs and their cognate ligands CD24 and CD52, in COVID-19. Further, we review clinical data on proposed therapeutics targeting DAMP pathways to treat SARS-CoV-2 infection and the regulation of these signaling cascades in COVID-19. We also discuss the potential impact of DAMP-mediated inflammation in other indications related to COVID-19, such as ARDS, endothelial dysfunction, hypercoagulation, and sepsis.

Dysregulation of TFH-B-TRM lymphocyte cooperation is associated with unfavorable anti-PD-1 responses in EGFR-mutant lung cancer

Patients with non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations exhibit an unfavorable response to PD-1 inhibitor through unclear mechanisms. Hypothesizing that EGFR mutations alter tumor-immune interactions, we compare tumor-infiltrating lymphocytes between EGFR mutant (EGFR-MT) and wild type (EGFR-WT) tumors through single-cell transcriptomic analysis. We find that B cells, CXCL13-producing follicular helper CD4⁺ T (T_FH)-like cells, and tissue-resident memory CD8⁺ T (T_RM)-like cells decreased in EGFR-MT tumors. The NOTCH-RBPJ regulatory network, which is vital for persistence of T_RM state, is perturbed, and the interactions between T_FH and B cells through the CXCL13-CXCR5 axis disappear in EGFR-MT tumors. Notably, the proportion of T_RM-like cells is predictive for anti-PD-1 response in NSCLC. Our findings suggest that the impairment of T_FH-B-T_RM cooperation in tertiary lymphoid structure formation, accompanied by the dysregulation of T_RM homeostasis and the loss of T_FH-B crosstalk, underlies unfavorable anti-PD-1 response in EGFR-MT lung tumors.

Identifying Lung Cancer Cell Markers with Machine Learning Methods and Single-Cell RNA-Seq Data

Non-small cell lung cancer is a major lethal subtype of epithelial lung cancer, with high morbidity and mortality. The single-cell sequencing technique plays a key role in exploring the pathogenesis of non-small cell lung cancer. We proposed a computational method for distinguishing cell subtypes from the different pathological regions of non-small cell lung cancer on the basis of transcriptomic profiles, including a group of qualitative classification criteria (biomarkers) and various rules. The random forest classifier reached a Matthew’s correlation coefficient (MCC) of 0.922 by using 720 features, and the decision tree reached an MCC of 0.786 by using 1880 features. The obtained biomarkers and rules were analyzed in the end of this study.

Targeted Approaches to T-Cell Lymphoma

The T-cell lymphomas are a rare group of Non-Hodgkin's lymphomas derived from mature T-lymphocytes. They are divided broadly into the Peripheral T-cell lymphomas and the Cutaneous T-cell lymphomas. Clinical outcomes vary widely but are generally unsatisfactory with current treatments. The development of an understanding of the various critical pathways in T-cell lymphogenesis and subsequent identification of therapeutic targets has led to a rapid expansion of the previously underwhelming T-cell lymphoma armament. This review aims to provide an up-to-date overview of the current state of targeted therapies in the T-cell lymphomas, including novel antibody-based treatments, small molecule inhibitors and immune-based therapies.

High expression of CD52 in adipocytes: a potential therapeutic target for obesity with type 2 diabetes

The aim of the present study was to evaluate the involvement of CD52 in adipocytes as well as to explore its effect on type 2 diabetes mellitus (T2DM), and to improve our understanding of the potential molecular events of obesity with type 2 diabetes. Global changes in the CD52 expression patterns were detected in adipocytes and preadipocytes derived from obese and lean individuals. In particular, CD52 was identified as significantly differentially upregulated and was analyzed, both in vitro and in vivo, using various approaches. In vitro experiments, CD52 was a significantly up-regulated mRNA in mature adipocytes and preadipocytes. In addition, CD52 gradually increased with the differentiation of preadipocytes. In vivo experiments, the expression of CD52 in high-fat diet (HFD) -fed mice tended to be higher than that in regular diet (RD) -fed mice. Further analysis showed that CD52 expression was positively correlated with Smad3 and TGF-β in mice, and the downregulation of CD52 was accompanied by increased glucose tolerance and insulin sensitivity. Moreover, a comparison of CD4+CD52^high T cells and CD4+CD52^low T cells showed that many T2DM-related genes were aberrantly expressed. Overall, CD52 may functioned as an important potential target for obesity with T2DM via TGF-β/Smad3 axis.

Integrated single-cell analysis of multicellular immune dynamics during hyperacute HIV-1 infection

Cellular immunity is critical for controlling intracellular pathogens, but individual cellular dynamics and cell-cell cooperativity in evolving human immune responses remain poorly understood. Single-cell RNA-sequencing (scRNA-seq) represents a powerful tool for dissecting complex multicellular behaviors in health and disease1,2 and nominating testable therapeutic targets3. Its application to longitudinal samples could afford an opportunity to uncover cellular factors associated with the evolution of disease progression without potentially confounding inter-individual variability4. Here, we present an experimental and computational methodology that uses scRNA-seq to characterize dynamic cellular programs and their molecular drivers, and apply it to HIV infection. By performing scRNA-seq on peripheral blood mononuclear cells from four untreated individuals before and longitudinally during acute infection5, we were powered within each to discover gene response modules that vary by time and cell subset. Beyond previously unappreciated individual- and cell-type-specific interferon-stimulated gene upregulation, we describe temporally aligned gene expression responses obscured in bulk analyses, including those involved in proinflammatory T cell differentiation, prolonged monocyte major histocompatibility complex II upregulation and persistent natural killer (NK) cell cytolytic killing. We further identify response features arising in the first weeks of infection, for example proliferating natural killer cells, which potentially may associate with future viral control. Overall, our approach provides a unified framework for characterizing multiple dynamic cellular responses and their coordination.

CD4+ CD52lo T-cell expression contributes to the development of systemic lupus erythematosus

The cell-surface glycoprotein CD52 is widely expressed in lymphocytes. CD4⁺CD52^hi T cells are functioning suppressor CD4⁺T cells. We investigated the role of the immune regulation of CD4⁺CD52 T cells in systemic lupus erythematosus (SLE). CD4⁺CD52^lo T cells were increased in SLE patients, in positive correlation with SLEDAI, anti-ds-DNA antibody, and IgG concentration. Circulating follicular helper-like T cells (Tfh-like cells) were also increased in SLE, in positive correlation with CD4⁺CD52^lo T cells. Chemokine receptor 8 (CCR8) expression in CD4⁺CD52^lo T cells was increased. In vitro experiments using CD4 T cells of SLE patients showed that thymus and activation-regulated chemokine (TARC), a ligand of CCR8, contributed to the development of CD4⁺CD52^hi T cells into CD4⁺CD52^lo T cells. Our findings suggest that CD4+CD52lo T-cell upregulation is involved in the production of pathogens by autoantibodies, and TARC may contribute to the development of SLE through an aberrant induction of CD4⁺CD52^lo T cells.

Global analysis of chromosome 1 genes among patients with lung adenocarcinoma, squamous carcinoma, large-cell carcinoma, small-cell carcinoma, or non-cancer

The present study aimed at investigating genetic variations, specific signal pathways, or biological processes of chromosome 1 genes between subtypes and stages of lung cancer and prediction of selected targeting genes for patient survival rate. About 537 patients with lung adenocarcinoma (ADC), 140 with lung squamous carcinoma (SCC), 9 with lung large-cell carcinoma (LCC), 56 with small-cell lung cancer (SCLC), and 590 without caner were integrated from 16 databases and analyzed in the present study. Three (ASPM, CDC20, KIAA1799) or 28 genes significantly up- or down-expressed in four subtypes of lung cancer. The activated cell division and down-regulated immune responses were identified in patients with lung cancer. Keratinocyte development associated genes S100 and SPRR families dominantly up-expressed in SCC and AKT3 and NRAS in SCLC. Subtype-specific genes of ADC, SCC, LCC, or SCLC were also identified. C1orf106, CAPN8, CDC20, COL11A1, CRABP2, and NBPF9 up-expressed at four stages of ADC. Fifty six related with keratinocytes or potassium channels up-expressed in three stages of SCC. CDC20, IL10, ECM1, GABPB2, CRABP2, and COL11A1 significantly predicted the poor overall survival of ADC patients and S100A2 and TIMM17A in SCC patients. Our data indicate that a number of altered chromosome 1 genes have the subtype and stage specificities of lung cancer and can be considered as diagnostic and prognosis biomarkers.

Establishment a CHO Cell Line Expressing Human CD52 Molecule

BACKGROUND

CD52 is a small glycoprotein with a GPI anchor at its C-terminus. CD52 is expressed by Normal and malignant T and B lymphocytes and monocytes. There are detectable amounts of soluble CD52 in plasma of patients with CLL and could be used as a tumor marker. Although the biological function of CD52 is unknown but it seems that CD52 may be involved in migration and activation of T-cells .The aim of this study was to clone and express human CD52 gene in CHO cell line and studying its function in more details.

METHODS

Based on GenBank databases two specific primers were designed for amplification of cd52 gene. Total RNA was extracted from Raji cell line and cDNA synthesized. Amplified fragment was cloned in pBudCE4.1 vector. The new construct was transfected to CHO-K1 cell line using electroporation method. Expression of recombinant CD52 protein was evaluated by Real time PCR and flow cytometry methods.

RESULTS

Amplification of CD52 gene using specific primers on Raji cDNA showed a 209 bp band. New construct was confirmed by PCR and restriction pattern and sequence analysis. The new construct was designated as pBudKT1. RT-PCR analysis detected cd52 mRNAs in transfected cells and Flow cytometry Results showed that 78.4 % of cells represented CD52 in their surfaces.

CONCLUSION

In conclusion, we established a human CD52 positive cell line, CHO-CD52, and the protein was expressed on the membrane. Cloning of the CD52 gene could be the first step for the production of therapeutic monoclonal antibodies and detection systems for soluble CD52 in biological fluids.