Cis-interaction between CD52 and T cell receptor complex interferes with CD4+ T cell activation in acute decompensation of cirrhosis.

BACKGROUND: Immune dysfunction contributes to a high rate of infection in patients with acute decompensation of cirrhosis. CD52 is a glycoprotein prominently expressed in lymphocytes. Immune regulation by CD52 may be involved in adaptive immune dysfunction in cirrhosis. This study aimed to investigate the function of CD52 on CD4+ T cells on the blood of patients with acute decompensation of cirrhosis. METHODS: The expression of CD52 in the peripheral blood lymphocytes of 49 patients with cirrhosis was investigated using flow cytometry and transcriptomics. Potential cis-membrane ligands of CD52 were discovered via proximity labelling followed by proteomics. The function of CD52 on antigen-specific activation of CD4+ T cells was examined using flow cytometry in CD52 CRISPR-Cas9 knockout primary T cells. FINDINGS: CD52 expression was elevated in CD4+ T cells in acute decompensation of cirrhosis, and this elevation was correlated with increased disease severity and mortality. Components of the T cell receptor complex including TCRß, CD3γ and CD3ε were identified and validated as cis-membrane ligands of CD52. Knockout of CD52 promoted antigen-specific activation, proliferation, and pro-inflammatory cytokine secretion. INTERPRETATION: Membrane bound CD52 demonstrated cis-interaction with the T cell receptor and served as a dynamic regulator of antigen-specific activation of CD4+ T cells. The upregulation of CD52 in the periphery of acute decompensation of cirrhosis hinders the recognition of the T cell receptor by MHC, contributing to impaired T cell function. The development of an alternative anti-CD52 antibody is required to restore T cell function and prevent infections in cirrhosis. FUNDING: This study was supported by the NIHR Imperial Biomedical Research Centre, Institute for Translational Medicine and Therapeutics (P74713), Wellcome Trust (218304/Z/19/Z), and Medical Research Council (MR/X009904/1 and MR/R014019/1).

CD52 knockdown inhibits aerobic glycolysis and malignant behavior of NSCLC cells through AKT signaling pathway.

CD52 is an important functional regulator involved in the development of human cancer. In this study, the clinical significance and biological function of CD52 in the malignant behavior of non-small cell lung cancer (NSCLC) were explored. In this study, immunohistochemical (IHC) staining was performed to determine the expression pattern of CD52 in NSCLC. Loss of function assays were used to evaluate the biological functions of CD52 in NSCLC cells in vitro and in vivo. Our data indicated that the expression of CD52 was significantly elevated in NSCLC and correlated with the patient prognosis. Functionally, downregulation of CD52 expression significantly suppressed the proliferation, migration, aerobic glycolysis and tumorigenesis of NSCLC cells. Moreover, CD52 regulated aerobic glycolysis of NSCLC cells through the AKT pathway. Furthermore, aerobic glycolysis induced by 2-DG inhibited the proliferation of NSCLC cells. In conclusion, CD52 knockdown inhibited aerobic glycolysis and malignant behavior of NSCLC cells through AKT signaling pathway, which may be employed in an alternative therapeutic target for NSCLC.

Evaluation of the paired-Cas9 nickase and RNA-guided FokI genome editing tools in precise integration of an anti-CD52 bicistronic monoclonal antibody expression construct at Chinese hamster ovary cells 18S rDNA locus.

INTRODUCTION: The aim of this study was to compare two CRISPR/Cas9-based orthogonal strategies, paired-Cas9 nickase (paired-Cas9n) and RNA-guided FokI (RFN), in targeting 18S rDNA locus in Chinese hamster ovary (CHO) cells and precisely integrating a bicistronic anti-CD52 monoclonal antibody (mAb) expression cassette into this locus. METHODS: T7E1 and high-resolution melt (HRM) assays were used to compare the ability of mentioned systems in inducing double-strand break (DSB) at the target site. Moreover, 5'- and 3'-junction polymerase chain reactions (PCR) were used to verify the accuracy of the targeted integration of the mAb expression cassette into the 18S rDNA locus. Finally, anti-CD52 mAb gene copy number was measured and, its expression was analyzed using ELISA and western blot assays. RESULTS: Our results indicated that both paired-Cas9n and RFN induced DSB at the target site albeit RFN performance was slightly more efficient in HRM analysis. We also confirmed that the anti-CD52 mAb cassette was accurately integrated at the 18S rDNA locus and the mAb was expressed successfully in CHO cells. CONCLUSION: Taken together, our findings elucidated that both paired-Cas9n and RFN genome editing tools are promising in targeting the 18S rDNA locus. Site specific integration of the bicistronic anti-CD52 mAb expression cassette at this locus in the CHO-K1 cells was obtained, using RFN. Moreover, proper expression of the anti-CD52 mAb at the 18S rDNA target site can be achieved using the bicistronic internal ribosome entry site (IRES)-based vector system.

CD52 mRNA expression predicts prognosis and response to immune checkpoint blockade in melanoma.

The immune-modulating protein CD52 attenuates lymphocyte function and is associated with autoimmune disorders, for example, multiple sclerosis (MS). CD52 represents a therapeutic target in MS and chronic lymphocytic leukemia (CLL). Its expression has prognostic and predictive value in CLL and is prognostic in breast cancer. Its significance in melanoma is unclear. We analyzed CD52 mRNA expression data from tumor bulk tissues of N = 445 untreated melanoma patients from The Cancer Genome Atlas (TCGA) Research Network and of N = 121 melanoma patients undergoing anti-PD-1 immune checkpoint blockade (ICB) with regard to outcome (overall survival [OS], disease control [DC], and progression-free survival [PFS]), single-cell RNA-Seq data of N = 4645 cells from N = 19 melanoma tissues, and N = 15,457 cells from normal skin provided by N = 5 donors. Higher CD52 mRNA expression was associated with favorable OS (hazard ratio (HR) = 0.820, [95% CI 0.734-0.916], p < .001) in non-ICB-treated melanoma and with PFS (HR = 0.875, [95% CI 0.775-0.989], p = .033) and DC (p = .005) in ICB-treated melanoma. CD52 expression correlated significantly with distinct immune cell subsets and correlated negatively with immune checkpoint expression in T cells. Moreover, our results suggest CD52 expression by a certain type of tissue-resident macrophages. CD52 mRNA was expressed in a small subgroup (8%) of immune checkpoint coexpressing melanoma cells. CD52 expression is associated with features of ICB response in melanoma. Concomitant ICB and anti-CD52 treatment requires critical review.

Overexpression of SIRT6 alleviates apoptosis and enhances cell viability and monoclonal antibody expression in CHO-K1 cells.

BACKGROUND: Chinese hamster ovary (CHO) cells are the most predominantly utilized host for the production of monoclonal antibodies (mAbs) and other complex glycoproteins. A major challenge in the process of CHO cell culture is the occurrence of cell death following different stressful conditions, which hinders the production yield. Engineering genes involved in pathways related to cell death is a remarkable strategy to delay apoptosis, improve cell viability and enhance productivity. SIRT6 is a stress-responsive protein that regulates DNA repair, maintains genome integrity, and is critical for longevity and cell survival in organisms. METHODS AND RESULTS: In this study, SIRT6 was stably overexpressed in CHO-K1 cells and the impact of its expression on apoptosis related gene expression profile, viability, apoptosis, and mAb productivity was investigated. While a significant increase was observed in Bcl-2 mRNA level, caspase-3 and Bax mRNA levels were decreased in the SIRT6 engineered cells compared to the parental CHO-K1 cells. Moreover, improved cell viability and decreased rate of apoptotic progression was observed in a SIRT6-derived clone in comparision to the CHO-K1 cells during 5 days of batch culture. anti-CD52 IgG1 mAb titers were improved up to 1.7- and 2.8-fold in SIRT6-derived clone during transient and stable expression, respectively. CONCLUSIONS: This study indicates the positive effects of SIRT6 overexpression on cell viability and anti-CD52 IgG1 mAb expression in CHO-K1 cells. Further studies are needed to examine the potential of SIRT6-engineered host cells for the production of recombinant biotherapeutics in industrial settings.

Late-onset toxicities of monoclonal antibodies in cancer patients.

Cancer therapy duration is variable and may take years, adding a new challenge of maintaining the best life quality for cancer survivors. In cancer patients, late-onset toxicities have been reported with monoclonal antibodies and may involve several body organs or systems. They are defined as an autoimmune illnesses that can happen months to years after treatment discontinuation. Late-onset toxicities have become a focus of clinical care and related research. After cancer therapy is completed, the patient should receive longitudinal follow-up to detect these late effects as early as possible. The current review summarizes the recently reported late-onset toxicities of four classes of monoclonal antibodies (anti-CD52, anti-CTLA-4, anti-PD-1 and anti-CD20) with guidance for the diagnostic tools, appropriate management and treatment.

Late-onset toxicities have been reported in cancer patients with monoclonal antibodies therapy and may involve several body organs or systems. They are defined as autoimmune illnesses that can happen months to years after treatment discontinuation. The reported late-onset toxicities include; bruises due to decreased platelet count associated with alemtuzumab, ipilimumab-induced pneumonitis, hepatitis, gastrointestinal disorders, cardiovascular complications and neurosarcoidosis. Moreover, endocrinal side effects of nivolumab, pembrolizumab-induced colitis, dermatological toxicities and acute encephalopathy, and rituximab-induced late-onset decrease in neutrophils count. Several treatment options are available for managing late-onset toxicities, including corticosteroids. After monoclonal antibodies therapy is completed in cancer patients, they should receive a longitudinal follow-up to detect these late effects as early as possible.

Alemtuzumab-induced immune phenotype and repertoire changes: implications for secondary autoimmunity.

Alemtuzumab is a monoclonal antibody that causes rapid depletion of CD52-expressing immune cells. It has proven to be highly efficacious in active relapsing-remitting multiple sclerosis; however, the high risk of secondary autoimmune disorders has greatly complicated its use. Thus, deeper insight into the pathophysiology of secondary autoimmunity and potential biomarkers is urgently needed. The most critical time points in the decision-making process for alemtuzumab therapy are before or at Month 12, where the ability to identify secondary autoimmunity risk would be instrumental. Therefore, we investigated components of blood and CSF of up to 106 multiple sclerosis patients before and after alemtuzumab treatment focusing on those critical time points. Consistent with previous reports, deep flow cytometric immune-cell profiling (n = 30) demonstrated major effects on adaptive rather than innate immunity, which favoured regulatory immune cell subsets within the repopulation. The longitudinally studied CSF compartment (n = 18) mainly mirrored the immunological effects observed in the periphery. Alemtuzumab-induced changes including increased numbers of naïve CD4+ T cells and B cells as well as a clonal renewal of CD4+ T- and B-cell repertoires were partly reminiscent of haematopoietic stem cell transplantation; in contrast, thymopoiesis was reduced and clonal renewal of T-cell repertoires after alemtuzumab was incomplete. Stratification for secondary autoimmunity did not show clear immununological cellular or proteomic traits or signatures associated with secondary autoimmunity. However, a restricted T-cell repertoire with hyperexpanded T-cell clones at baseline, which persisted and demonstrated further expansion at Month 12 by homeostatic proliferation, identified patients developing secondary autoimmune disorders (n = 7 without secondary autoimmunity versus n = 5 with secondary autoimmunity). Those processes were followed by an expansion of memory B-cell clones irrespective of persistence, which we detected shortly after the diagnosis of secondary autoimmune disease. In conclusion, our data demonstrate that (i) peripheral immunological alterations following alemtuzumab are mirrored by longitudinal changes in the CSF; (ii) incomplete T-cell repertoire renewal and reduced thymopoiesis contribute to a proautoimmune state after alemtuzumab; (iii) proteomics and surface immunological phenotyping do not identify patients at risk for secondary autoimmune disorders; (iv) homeostatic proliferation with disparate dynamics of clonal T- and B-cell expansions are associated with secondary autoimmunity; and (v) hyperexpanded T-cell clones at baseline and Month 12 may be used as a biomarker for the risk of alemtuzumab-induced autoimmunity.

[Preparation of CD52-targeted chimeric antigen receptor-modified T cells and their anti-leukemia effects].

Objective: To construct chimeric antigen receptor (CAR) T cells targeting CD52 (CD52 CAR-T) and validate the effect of CD52 CAR-T cells on CD52-positive leukemia. Methods: A second-generation CD52-targeting CAR bearing 4-1BB costimulatory domain was ligated into a lentiviral vector through molecular cloning. Lentivirus was prepared and packaged by 293 T cells with a four-plasmid system. Fluorescein was used to label cell surface antigens to evaluate the phenotype of CD52 CAR-T cells after infection. Flow cytometry and ELISA were used to evaluate the specific cytotoxicity of CD52 CAR-T cells to CD52-positive cell lines in vitro. Results: ①A pCDH-CD52scFv-CD8α-4-1BB-CD3ζ-GFP expressing plasmid was successfully constructed and used to transduce T cells expressing a novel CD52-targeting CAR. ②On day 6, CD52-positive T cells were almost killed by CD52-targeted CAR-T post lentivirus transduction [CD52 CAR-T (4.48 ± 4.99) %, vs Vector-T (56.58±19.8) %, P=0.011]. ③T cells transduced with the CAR targeting CD52 showed low levels of apoptosis and could be expanded long-term ex vivo. ④The CD52 CAR could promote T cell differentiation into central and effector memory T cells, whereas the proportion of T cells with a CD45RA(+) effector memory phenotype were reduced. ⑤CD52 CAR-T cells could specifically kill CD52-positive HuT78-19t cells but had no killing effect on CD52-negative MOLT4-19t cells. For CD52 CAR-T cells, the percentage of residual of HuT78-19t cells was (2.66±1.60) % at an the E:T ratio of 1∶1 for 24 h, while (56.66±5.74) % of MOLT4-19t cells survived (P<0.001) . ⑥The results of a degranulation experiment confirmed that HuT78-19t cells significantly activated CD52 CAR-T cells but not MOLT4-19t cells[ (57.34±11.25) % vs (13.06± 4.23) %, P<0.001]. ⑦CD52 CAR-T cells released more cytokines when co-cultured with HuT78-19t cells than that of vector-T cells [IFN-γ: (3706±226) pg/ml, P<0.001; TNF-α: (1732±560) pg/ml, P<0.01]. Conclusions: We successfully prepared CD52 CAR-T cells with anti-leukemia effects, which might provide the foundation for further immunotherapy.

Loss of thymic function promotes EAE relapse in anti-CD52-treated mice.

Anti-CD52 treatment creates a long-lasting CD4 T cell lymphopenia and reduces multiple sclerosis (MS) relapses in humans. In contrast, anti-CD52 therapy at disease onset more fully suppresses experimental autoimmune encephalomyelitis (EAE) in mice, and T cell repopulation is rapid. To test whether prolonged T cell lymphopenia promotes relapses, we thymectomized mice prior to EAE induction and anti-CD52 treatment. Thymectomy greatly reduced the number of recent thymic emigrant T cells and was associated with a prolonged reduction in CD4 T cells in peripheral blood. Two-thirds of thymectomized C57BL/6 mice had an EAE relapse post anti-CD52 treatment, while no surgery and sham surgery euthymic controls remained relapse-free. These data demonstrate that thymus function can alter the effectiveness of anti-CD52 treatment.

Impact of an anti-infective screening and monitoring protocol together with infectious disease consultation in preventing infective adverse events in patients treated with anti-CD20/CD52 agents for multiple sclerosis.

BACKGROUND: Monoclonal antibodies have been a milestone in the treatment of multiple sclerosis (MS). Infective complications have been observed in patients on agents targeting lymphoid cells' surface antigens, namely anti-CD52 (alemtuzumab) and anti-CD20 agents (ocrelizumab and rituximab). Despite increasing emerging data, there is no standardized consensus regarding pre-treatment testing, vaccinations, and patient education before and during MS therapy or optimal infection-control strategies. METHODS: We led a retrospective/prospective real-life study to evaluate the effectiveness of a program of screening and prophylaxis for infective adverse events in patients with multiple sclerosis and related disorders treated with drugs directed against CD20/52 antigens. All patients referring to the MS Clinical Care and Research Center, University of Naples "Federico II", who started on alemtuzumab, ocrelizumab or rituximab (off-label use) from 1 November 2015 to 30 June 2019 were recruited. From the 1st of February 2018 patients underwent a microbiological screening and were evaluated by an infectious disease specialist (IDs) before monoclonal antibodies infusion to rule out active infections. We evaluated incidence of infective complications and predictors before (retrospectively)and after (prospectively) the introduction of the above-mentioned anti-infective program. RESULTS: We enrolled 275 patients, 104 retrospectively (pre-intervention group, PRE) and 171 prospectively (post-intervention group, POST). In PRE group, most patients were treated with alemtuzumab (58% vs 32%, p < 0.001), were more frequently DMT naïve (48% vs 36%, p = 0.044) or had received fingolimod in the past (48% vs 28%, p = 0.044) and the follow-up period was longer than in POST group (750 vs 191 days, p < 0.001). In POST group, patients were older (median age 47 vs 42 years, p = 0.030) and mostly received OCR (54% vs 14%, p < 0.001). Lymphopenia at baseline was significantly more commonly observed in PRE arm (47% vs 8%, p < 0.001). A total of 39 patients (38%) in PRE arm and 42 patients (25% in POST) group experienced one or more infections (p = 0.022); severe infections were significantly more common in PRE patients (23% vs 14%, p = 0.022). Our anti-infective program was associated with a lower IAE incidence both at univariate and multivariate analysis (aHR of infective events in PRE group: 3.652 [CI: 9.03-94.19], p < 0.001). Moreover, DMT naïve patients significantly experienced fewer infective complications (aHR: 0.470, [CI: 1.02-2.55], p = 0.040). CONCLUSIONS: A risk mitigation program including infectious disease consultation and standardized screening and prophylactic protocols was effective in reducing infective adverse events in patients receiving anti CD20/CD52 agents for MS.

Engineering T-Cell Resistance to HIV-1 Infection via Knock-In of Peptides from the Heptad Repeat 2 Domain of gp41.

Previous studies suggest that short peptides from the heptad repeat 2 (HR2) domain of gp41 expressed on the cell surface are more potent inhibitors of HIV-1 entry than soluble analogs. However, their therapeutic potential has only been examined using lentiviral vectors. Here, we aimed to develop CRISPR/Cas9-based fusion inhibitory peptide knock-in (KI) technology for the generation and selection of HIV-1-resistant T cells. First, we embedded a series of HIV-1 fusion inhibitory peptides in CD52, the shortest glycosylphosphatidylinositol (GPI)-anchored protein, which efficiently delivers epitope tags to the cell surface and maintains a sufficient level of KI. Among the seven peptides tested, MT-C34, HP-23L, and 2P23 exhibited significant activity against both cell-free and cell-to-cell HIV-1 infection. The shed variant of MT-C34 provided insufficient protection against HIV-1 due to its low concentration in the culture medium. Using Cas9 plasmids or ribonucleoprotein electroporation and peptide-specific antibodies, we sorted CEM/R5 cells with biallelic KI of MT-C34 and 2P23 peptides at the CXCR4 locus. In combination, these peptides provided a higher level of protection than individual KI. By extending homology arms and cloning donor DNA into a plasmid containing signals for nuclear localization, we achieved KI of MT-C34 into the CXCR4 locus and HIV-1 proviral DNA at levels of up to 35% in the T-cell line and up to 4 to 5% in primary CD4 lymphocytes. Compared to lentiviral delivery, KI resulted in the higher MT-C34 surface expression and stronger protection of lymphocytes from HIV-1. Thus, we demonstrate that KI is a viable strategy for peptide-based therapy of HIV infection. IMPORTANCE HIV is a human lentivirus that infects CD4-positive immune cells and, when left untreated, manifests in the fatal disease known as AIDS. Antiretroviral therapy (ART) does not lead to viral clearance, and HIV persists in the organism as a latent provirus. One way to control infection is to increase the population of HIV-resistant CD4 lymphocytes via entry molecule knockout or expression of different antiviral genes. Peptides from the heptad repeat (HR) domain of gp41 are potent inhibitors of HIV-1 fusion, especially when designed to express on the cell surface. Individual gp41 peptides encoded by therapeutic lentiviral vectors have been evaluated and some have entered clinical trials. However, a CRISPR/Cas9-based gp41 peptide delivery platform that operates through concomitant target gene modification has not yet been developed due to low knock-in (KI) rates in primary cells. Here, we systematically evaluated the antiviral activity of different HR2 peptides cloned into the shortest carrier molecule, CD52. The resulting small-size transgene constructs encoding selected peptides, in combination with improvements to enhance donor vector nuclear import, helped to overcome precise editing restrictions in CD4 lymphocytes. Using KI into CXCR4, we demonstrated different options for target gene modification, effectively protecting edited cells against HIV-1.

Anti-CD52 antibody treatment in murine experimental autoimmune encephalomyelitis induces dynamic and differential modulation of innate immune cells in peripheral immune and central nervous systems.

Anti-CD52 antibody (anti-CD52-Ab) leads to a rapid depletion of T and B cells, followed by reconstitution of immune cells with tolerogenic characteristics. However, very little is known about its effect on innate immune cells. In this study, experimental autoimmune encephalomyelitis mice were administered murine anti-CD52-Ab to investigate its effect on dendritic cells and monocytes/macrophages in the periphery lymphoid organs and the central nervous system (CNS). Our data show that blood and splenic innate immune cells exhibited significantly increased expression of MHC-II and costimulatory molecules, which was associated with increased capacity of activating antigen-specific T cells, at first day but not three weeks after five daily treatment with anti-CD52-Ab in comparison with controls. In contrast to the periphery, microglia and infiltrating macrophages in the CNS exhibited reduced expression levels of MHC-II and costimulatory molecules after antibody treatment at both time-points investigated when compared to controls. Furthermore, the transit response of peripheral innate immune cells to anti-CD52-Ab treatment was also observed in the lymphocyte-deficient SCID mice, suggesting the changes are not a direct consequence of the mass depletion of lymphocytes in the periphery. Our study demonstrates a dynamic and tissue-specific modulation of the innate immune cells in their phenotype and function following the antibody treatment. The findings of differential modulation of the microglia and infiltrating macrophages in the CNS in comparison with the innate immune cells in the peripheral organs support the CNS-specific beneficial effect of alemtuzumab treatment on inhibiting neuroinflammation in multiple sclerosis patients.

Preclinical pharmacology and toxicology evaluation of an anti-CD52 monoclonal antibody produced by perfusion fermentation process.

Anti-cluster of differentiation 52 (CD52) monoclonal antibody (mAb) has been employed in the treatment of chronic lymphoblastic leukemia and multiple sclerosis. Previously we developed a perfusion process to produce the biosimilar mAb named "Mab-TH." A series of quality assessments was conducted in the fields of structural identification, purity analysis, and activity measurement. After these quality researches, this report laid emphasis on preclinical pharmacology and toxicology evaluation. Mab-TH was characterized in biological, pharmacological, and toxicological properties in comparison with the original drug, alemtuzumab. Binding activity and immune-dependent toxicity as in vitro activity were evaluated. Severe immunodeficient mice transplanted with a human leukemia cell line were also used as an in vivo pharmacological model and a 4-week repeated dosing study in cynomolgus monkeys was conducted to evaluate the safety differences. Our results demonstrated that Mab-TH, the anti-CD52 antibody generated by a perfusion process, had high similarity in in vitro and in vivo activities compared with alemtuzumab in relevant preclinical models. The results supported it as a biosimilar candidate for clinical evaluation.

Dynamic changes in human single-cell transcriptional signatures during fatal sepsis.

Systemic infections, especially in patients with chronic diseases, may result in sepsis: an explosive, uncoordinated immune response that can lead to multisystem organ failure with a high mortality rate. Patients with similar clinical phenotypes or sepsis biomarker expression upon diagnosis may have different outcomes, suggesting that the dynamics of sepsis is critical in disease progression. A within-subject study of patients with Gram-negative bacterial sepsis with surviving and fatal outcomes was designed and single-cell transcriptomic analyses of peripheral blood mononuclear cells (PBMC) collected during the critical period between sepsis diagnosis and 6 h were performed. The single-cell observations in the study are consistent with trends from public datasets but also identify dynamic effects in individual cell subsets that change within hours. It is shown that platelet and erythroid precursor responses are drivers of fatal sepsis, with transcriptional signatures that are shared with severe COVID-19 disease. It is also shown that hypoxic stress is a driving factor in immune and metabolic dysfunction of monocytes and erythroid precursors. Last, the data support CD52 as a prognostic biomarker and therapeutic target for sepsis as its expression dynamically increases in lymphocytes and correlates with improved sepsis outcomes. In conclusion, this study describes the first single-cell study that analyzed short-term temporal changes in the immune cell populations and their characteristics in surviving or fatal sepsis. Tracking temporal expression changes in specific cell types could lead to more accurate predictions of sepsis outcomes and identify molecular biomarkers and pathways that could be therapeutically controlled to improve the sepsis trajectory toward better outcomes.

Anti-CD52 Therapy for Multiple Sclerosis: An Update in the COVID Era.

CD52 is a small surface glycoprotein composed of 12 amino acids. CD52 is found mostly on the surface of mature immune cells, such as lymphocytes, monocytes, eosinophils, and dendritic cells, as well as the male genital tract: within the epididymis and on the surface of mature sperm. Low CD52 expression is also found in neutrophils. CD52 function is not fully understood, although experiments with anti-CD52 antibodies have shown that CD52 is essential for lymphocyte transendothelial migration and may contribute to costimulation of CD4+ T cells and T-cell activation and proliferation. Although knowledge about exact CD52 function is still poor, CD52 presence on the surface of a broad spectrum of immune cells makes it a therapeutic target, especially in immunomediated diseases, such as multiple sclerosis. In multiple sclerosis, alemtuzumab is registered for adult patients with the relapsing-remitting form of the disease defined by clinical and imaging features. Despite the high efficacy of the drug, the main issue is its safety. The main adverse effects of alemtuzumab are associated with drug infusion due to cytokine release and cytotoxic effects of antibodies associated with lymphocyte depletion, which leads to immunosuppression, and secondary autoimmunity that may be the effect of excessive B-cell repopulation and cancer. This review presents current knowledge on the drug's mechanism of action, efficacy and safety data from clinical trials, and real-world observations, including available though scarce data on using alemtuzumab in the COVID era.

Alemtuzumab scFv fragments and CD52 interaction study through molecular dynamics simulation and binding free energy.

Specific antibody-antigen recognition is crucial for the immune response. Knowledge of molecular interaction details in the recognition process is fundamental for the rational design of antibodies with improved properties. We used state-of-the-art computer simulation tools to deepen the molecular-level understanding of the interactions between the monoclonal antibody Alemtuzumab and its antigen, the CD52 membrane receptor, of great biotechnological importance. Thus, we seek such responses by modeling the interaction of native and known mutants single-chain fragment variable (scFv) of Alemtuzumab with CD52 inserted in a membrane model to mimic the physiological conditions of antibody-antigen binding. Extensive molecular dynamics simulations of the interaction between Alemtuzumab's scFvs and CD52 promoted greater understanding of the structural and energetic bases, which can be translated into the biological action and affinity of this antibody. The quantification of the scFv-CD52 complexes binding free energy (ΔGbind) by Molecular Mechanics-Poisson-Boltzmann Surface Area (MM-PBSA) correlated with the experimental binding energies described before. Thus, the mutants D53K, K54D, and K56D resulted in less attractive ΔGbind, therefore lower scFv-CD52 affinity than the native scFv. On the other hand, K56D and K54D/K56D showed lower binding to CD52. These Results revealed that the model system mimicking an environment close to the physiological with the presence of the CD52 in a membrane model proved essential for this system's study. The present study allowed to unveil the molecular mechanisms involved in antigen-antibody interaction and the effects of mutations. Thus, these mechanisms may be explored in the Alemtuzumab variants' rational design with enhanced properties.

Efficacy and safety of alemtuzumab over 6 years: final results of the 4-year CARE-MS extension trial.

BACKGROUND: In the 2-year CARE-MS I and II trials, alemtuzumab 12 mg administered on 5 consecutive days at core study baseline and on 3 consecutive days 12 months later significantly improved outcomes versus subcutaneous interferon beta-1a (SC IFNB-1a) in relapsing-remitting multiple sclerosis patients. Here, we present the final 6-year CARE-MS extension trial results (CAMMS03409), and compare outcomes over 6 years in patients randomized to both treatment groups at core study baseline. METHODS: Over a 4-year extension, alemtuzumab patients (alemtuzumab-only) received as-needed additional alemtuzumab (⩾12 months apart) for disease activity after course 2. SC IFNB-1a patients who entered the extension discontinued SC IFNB-1a and received 2 alemtuzumab 12 mg courses (IFN-alemtuzumab), followed by additional, as-needed, alemtuzumab. RESULTS: Through year 6, 63% of CARE-MS I and 50% of CARE-MS II alemtuzumab-only patients received neither additional alemtuzumab nor other disease-modifying therapy, with lasting suppression of disease activity, improved disability, and slowing of brain volume loss (BVL). In CARE-MS I patients (treatment-naive; less disability; shorter disease duration), disease activity and BVL were significantly reduced in IFN-alemtuzumab patients, similar to alemtuzumab-only patients at year 6. Among CARE-MS II patients (inadequate response to prior treatment; more disability; longer disease duration), alemtuzumab significantly improved clinical and magnetic resonance imaging outcomes, including BVL, in IFN-alemtuzumab patients; however, disability outcomes were less favorable versus alemtuzumab-only patients. Safety profiles, including infections and autoimmunities, following alemtuzumab were similar between treatment groups. CONCLUSION: This study demonstrates the high efficacy of alemtuzumab over 6 years, with a similar safety profile between treatment groups. CLINICALTRIALSGOV IDENTIFIERS: NCT00530348; NCT00548405; NCT00930553.

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-ß in mice, and the downregulation of CD52 was accompanied by increased glucose tolerance and insulin sensitivity. Moreover, a comparison of CD4+CD52high T cells and CD4+CD52low 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-ß/Smad3 axis.

The immune-related gene CD52 is a favorable biomarker for breast cancer prognosis.

BACKGROUND: An increasing number of studies have demonstrated a role for the tumor microenvironment in tumorigenesis, disease progression, and therapeutic response. This present study aimed to screen the significant immune-related genes and their possible role in the prognosis of breast cancer (BRCA). METHODS: The transcriptome data and clinical data of breast cancer were collected from The Cancer Genome Atlas (TCGA), and the immune scores and stromal scores were calculated by ESTIMATE algorithm. The differentially expressed genes were screened base on immune and stromal scores (high score vs. low score), than the intersected genes were used for subsequent functional enrichment analysis and protein-protein interaction (PPI) analysis. Furthermore, the key gene was identified by the intersection of the hub genes of PPI network and the prognostic genes of breast cancer. Finally, we explored the infiltration of immune cells of BRCA base on the CIBERSORT algorithm, and analysis the relationship between key gene and immune cells. RESULTS: High levels of CD52 expression were detected in the early stages of breast cancer and were associated with favorable prognosis. Overexpression of CD52 led to higher infiltrations of M1 macrophages, monocytes, T follicular helper cells, and resting memory CD4 T cells. Downregulation of CD52 resulted in high infiltrations of M2 macrophages. Therefore, high expression of CD52 may negatively regulate the infiltration of M2 macrophages but accelerate the infiltration of anti-cancer immune cells, and thus, high expression of CD52 may have a protective effect in breast cancer patients. CONCLUSIONS: CD52 can increase the infiltration of anti-cancer immune cells but inhibit the infiltration of M2 macrophages, thereby improving the prognosis of breast cancer patients.

Mouse CD52 is Predominantly Expressed in the Cauda Epididymis, Regulated by Androgen and Lumicrine Factors.

BACKGROUND: Sperm maturation takes place through contact between sperm and proteins produced in the epididymal lumen. CD52 had been characterised in the sperm; however, the expression and its regulation in the epididymis are mostly unknown. AIM: This study aimed to analyse the expression and regulation of CD52 in the mouse epididymis. SETTING AND DESIGN: Experimental design was used in this study. MATERIALS AND METHODS: Epididymis tissues from mice strain Deutch Democratic Yokohama were used as sources of total RNA. Bioinformatic tool was used to predict signal peptides. Quantitative real-time reverse transcription-polymerase chain reaction was used to analyse tissue distribution, androgen, testicular factors dependency and postnatal development. STATISTICAL ANALYSIS: One-way analysis of variance was used to analyse differences between treatment and control untreated group. P < 0.05 was determined as a significant difference. RESULTS: CD52 amino acid sequence contains a signal peptide, indicating it is a secretory protein. CD52 exhibited region-specific expression in the epididymis, with the highest level being in the cauda. CD52 expression was regulated by androgen indicated by a significant downregulation at day 1 and day 3 following a castration (P < 0.05). Dependency on androgen was confirmed by injection of exogenous testosterone which prevented downregulation by 50%. Moreover, lumicrine factors also influenced CD52 expression indicated by ligation of efferent duct which also reduced expression at day 1 to day 5 following the ligation (P < 0.05). CD52 expression was developmentally regulated. This was shown by increase in the level of expression starting at day 15 postnatally. CONCLUSION: CD52 shows characteristics of genes involved in sperm maturation in the epididymis.