Ccl2-Induced Regulatory T Cells Balance Inflammation Through Macrophage Polarization During Liver Reconstitution.

Inflammation is highlighted as an initial factor that helps orchestrate liver reconstitution. However, the precise mechanisms controlling inflammation during liver reconstitution have not been fully elucidated. In this study, a clear immune response is demonstrated during hepatic reconstitution. Inhibition of the hepatic inflammatory response retards liver regeneration. During this process, Ccl2 is primarily produced by type 1 innate lymphoid cells (ILC1s), and ILC1-derived Ccl2 recruits peripheral ILC1s and regulatory T cells (Tregs) to the liver. Deletion of Ccl2 or Tregs exacerbates hepatic injury and inflammatory cytokine release, accelerating liver proliferation and regeneration. The adoption of Tregs and IL-10 injection reversed these effects on hepatocyte regenerative proliferation. Additionally, Treg-derived IL-10 can directly induce macrophage polarization from M1 to M2, which alleviated macrophage-secreted IL-6 and TNF-α and balanced the intrahepatic inflammatory milieu during liver reconstitution. This study reveals the capacity of Tregs to modulate the intrahepatic inflammatory milieu and liver reconstitution through IL-10-mediated macrophage polarization, providing a potential opportunity to improve hepatic inflammation and maintain homeostasis.

Diatom pyrenoids are encased in a protein shell that enables efficient CO2 fixation.

Pyrenoids are subcompartments of algal chloroplasts that increase the efficiency of Rubisco-driven CO2 fixation. Diatoms fix up to 20% of global CO2, but their pyrenoids remain poorly characterized. Here, we used in vivo photo-crosslinking to identify pyrenoid shell (PyShell) proteins, which we localized to the pyrenoid periphery of model pennate and centric diatoms, Phaeodactylum tricornutum and Thalassiosira pseudonana. In situ cryo-electron tomography revealed that pyrenoids of both diatom species are encased in a lattice-like protein sheath. Single-particle cryo-EM yielded a 2.4-Å-resolution structure of an in vitro TpPyShell1 lattice, which showed how protein subunits interlock. T. pseudonana TpPyShell1/2 knockout mutants had no PyShell sheath, altered pyrenoid morphology, and a high-CO2 requiring phenotype, with reduced photosynthetic efficiency and impaired growth under standard atmospheric conditions. The structure and function of the diatom PyShell provide a molecular view of how CO2 is assimilated in the ocean, a critical ecosystem undergoing rapid change.

Dendritic nanomedicine enhances chemo-immunotherapy by disturbing metabolism of cancer-associated fibroblasts for deep penetration and activating function of immune cells.

Inefficient drug penetration hurdled by the stroma in the tumor tissue leads to a diminished therapeutic effect for drugs and a reduced infiltration level of immune cells. Herein, we constructed a PEGylated dendritic epirubicin (Epi) prodrug (Epi-P4D) to regulate the metabolism of cancer-associated fibroblasts (CAFs), thus enhancing Epi penetration into both multicellular tumor spheroids (MTSs) and tumor tissues in mouse colon cancer (CT26), mouse breast cancer (4T1) and human breast cancer (MDA-MB-231) models. Enhanced cytotoxicity against CT26 MTSs and remarkable antitumor efficacy of Epi-P4D were ascribed to reduced fibronectin, α-SMA, and collagen secretion. Besides, thinning of the tumor tissue stroma and efficient eradication of tumor cells promoted the immunogenic cell death effect for dendritic cell (DC) maturation and subsequent immune activation, including elevating the CD4+ T cell population, reducing CD4+ and CD8+ T cell hyperactivation and exhaustion, and amplifying the natural killer (NK) cell proportion and effectively activating them. As a result, this dendritic nanomedicine thinned the stroma of tumor tissues to enhance drug penetration and facilitate immune cell infiltration for elevated antitumor efficacy.

Distinct Immune Homeostasis Remodeling Patterns after HLA-Matched and Haploidentical Transplantation.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a widely used treatment for a variety of hematopoietic disorders, and also provides a valuable platform for investigating the development of donor-derived immune cells in recipients post-HSCT. The immune system remodels from the donor to the recipient during allo-HSCT. However, little is known about the cell profile alterations as donor homeostasis rebalances to recipient homeostasis following HSCT. Here, multi-omics technology is applied at both the single cell and bulk sample levels, as well as spectrum flow cytometry and fluorescent transgenic mouse models, to dissect the dynamics of the rebalanced homeostatic immune system in recipients after allo-HSCT. The data reveal that all immune subpopulations observed in donors are successfully restored in recipients, though with varying levels of abundance. The remodeling of immune homeostasis exhibits different patterns in HLA-matched and haploidentical HSCT, highlighting distinct biases in T cell reconstitution from the central and peripheral pathways. Furthermore, ZNF683 is critical for maintaining the persistence and quiescence of CD8 T-cell in haploidentical HSCT. The research can serve as a foundation for developing novel strategies to induce immune tolerance.

Safety of the Immediate Reconstitution of Poly-l-Lactic Acid for Facial and Body Treatment-A Multicenter Retrospective Study.

BACKGROUND: Poly-l-lactic acid (PLLA-SCA; Sculptra) was approved in 1999 in Europe and 2004 in United States as a collagen biostimulator. It is a freeze-dried preparation containing 150 mg PLLA-SCA per vial and, since approval, has been recommended to be reconstituted 72 h before treatment, which can hinder its use in clinical practice. In 2021, the manufacturer authorized the reconstitution of PLLA-SCA immediately before use. OBJECTIVE: To evaluate adverse events in patients treated with immediately reconstituted PLLA-SCA on the face, body, and scars. METHOD: This was a retrospective analysis of medical records of patients treated with immediately reconstituted PLLA-SCA for aesthetic purposes from January 1, 2021, to December 31, 2021, at two medical centers. RESULTS: A total of 274 treatment sessions were conducted on 167 patients (ranging from 1 to 5 sessions per patient). Of these, 228 sessions (151 patients) targeted the face, 39 sessions (22 patients) addressed the body, and 7 sessions (5 patients) focused on scars. The mean final concentration of PLLA-SCA was 15.30 mg/mL for the face, 8.35 mg/mL for the body, and 10.53 mg/mL for scars. The majority of injections were administered with a blunt cannula (face: 87.3%, body: 100%, scars: 57%), and in 6 out of 7 scar treatments, PLLA-SCA was additionally applied topically after fractional treatment. One patient developed a PLLA-SCA nodule 30 days after facial treatment, which resolved after two saline injections. The most common adverse events were bruising (face: 6.57%, body: 7.69%) and mild pain (face: 3.07%). No events required further intervention. CONCLUSION: This study reports an adverse event profile with immediately reconstituted PLLA-SCA, used on the face, body, and scars, similar to that reported with PLLA-SCA reconstituted 72 h prior to use. TRIAL REGISTRATION: This was a retrospective study of medical records at two medical centers, and trial registration was not required.

MHC class I and II-deficient humanized mice are suitable tools to test the long-term antitumor efficacy of immune checkpoint inhibitors and T-cell engagers.

BACKGROUND: Immunodeficient mice engrafted with peripheral blood mononuclear cells (PBMCs) are models to study new cancer immunotherapy agents. However, this approach is associated with xenograft-versus-host disease (xGVHD), which starts early after PBMC transfer and limits the duration and interpretation of experiments. Here, we explore different approaches to overcome xGVHD and better support the development of cancer immunotherapies. METHODS: Immunodeficient NOD-scid IL2Rgnull (NSG) mice were intravenously transferred with human PBMCs and subcutaneously co-engrafted with HT29 human colon carcinoma cells. Diverse strategies to reduce xGVHD while preserving the antitumor activity of human immune cells were evaluated: (1) ex vivo immune graft modification by depleting CD4+ T cells pre-transfer using magnetic beads, (2) post-transplantation cyclophosphamide administration to eliminate proliferating xenoreactive T-cell clones and (3) using major histocompatibility complex (MHC) class I and II-deficient NSG mice: (Kb Db)null (IA)null (MHC-dKO NSG). Body weight and plasma murine alanine aminotransferase levels were measured as indicators of xGVHD and tumor size was measured every 2-3 days to monitor antitumor activity. The antitumor effects and pharmacodynamics of nivolumab plus ipilimumab and an anti-epithelial cell adhesion molecule (EpCAM)/CD3 T-cell engager (αEpCAM/CD3 bispecific antibody (BsAb)) were evaluated in the model. RESULTS: CD4+ T-cell depletion attenuates xGVHD but also abrogates the antitumor activity. Cyclophosphamide limits the antitumor response and does not substantially prevent xGVHD. In contrast, xGVHD was significantly attenuated in MHC-dKO NSG recipients, while the antitumor effect of human PBMCs was preserved. Furthermore, the administration of nivolumab plus ipilimumab caused exacerbated xGVHD in conventional NSG mice, thereby precluding the observation of their antitumor effects. Severe xGVHD did not occur in MHC-dKO NSG mice thus enabling the study of complete and durable tumor rejections. Similarly, NSG mice treated with an αEpCAM/CD3 BsAb showed complete tumor regressions, but died due to xGVHD. In contrast, MHC-dKO NSG mice on treatment with the αEpCAM/CD3 BsAb achieved complete tumor responses without severe xGVHD. A significant proportion of mice rendered tumor-free showed tumor rejection on rechallenge with HT29 cells without further treatment. Finally, tumor-infiltrating CD8+ T-cell number increase, activation and CD137 upregulation were observed on αEpCAM/CD3 BsAb treatment. CONCLUSION: Humanized MHC-dKO immunodeficient mice allow and refine the preclinical testing of immunotherapy agents for which experimentation is precluded in conventional immunodeficient mice due to severe xGVHD.

Insights into Transient Dimerisation of Carnitine/Acylcarnitine Carrier (SLC25A20) from Sarkosyl/PAGE, Cross-Linking Reagents, and Comparative Modelling Analysis.

The carnitine/acylcarnitine carrier (CAC) is a crucial protein for cellular energy metabolism, facilitating the exchange of acylcarnitines and free carnitine across the mitochondrial membrane, thereby enabling fatty acid ß-oxidation and oxidative phosphorylation (OXPHOS). Although CAC has not been crystallised, structural insights are derived from the mitochondrial ADP/ATP carrier (AAC) structures in both cytosolic and matrix conformations. These structures underpin a single binding centre-gated pore mechanism, a common feature among mitochondrial carrier (MC) family members. The functional implications of this mechanism are well-supported, yet the structural organization of the CAC, particularly the formation of dimeric or oligomeric assemblies, remains contentious. Recent investigations employing biochemical techniques on purified and reconstituted CAC, alongside molecular modelling based on crystallographic AAC dimeric structures, suggest that CAC can indeed form dimers. Importantly, this dimerization does not alter the transport mechanism, a phenomenon observed in various other membrane transporters across different protein families. This observation aligns with the ping-pong kinetic model, where the dimeric form potentially facilitates efficient substrate translocation without necessitating mechanistic alterations. The presented findings thus contribute to a deeper understanding of CAC's functional dynamics and its structural parallels with other MC family members.

Herpes Vegetans in a Patient With Acquired Immunodeficiency Syndrome (AIDS) in the Setting of Immune Reconstitution Inflammatory Syndrome.

Herpes simplex virus (HSV) infections classically present as a vesicular eruption on an erythematous base; however, viral infections may present much differently in the setting of immune deficiency. Herpes vegetans is an atypical presentation of HSV that occurs in immunocompromised patients, typically those with human immunodeficiency virus infection and acquired immunodeficiency syndrome (AIDS). Herpes vegetans is characterized by hyperkeratotic, exophytic, and, sometimes, ulcerated nodules, often with a chronic and persistent course. Herein, we present an interesting example of biopsy-confirmed anogenital herpes vegetans in a 61-year-old male with AIDS in the setting of immune reconstitution inflammatory syndrome, an association that is less frequently described. This case serves as an important reminder to consider atypical presentations of infectious disease when examining immunocompromised patients, as prompt diagnosis and treatment are essential in this population.

Alterations in circulating immunoregulatory proteins discriminate poor CD4 T lymphocyte trajectories in people with HIV on suppressive antiretroviral therapy.

Despite the success in the management of HIV with antiretroviral therapy (ART), people with HIV (PWH) have a heightened state of immune activation and inflammation, and an estimated 10%-40% demonstrate poor CD4 T-cell reconstitution, thereby increasing their mortality and morbidity risk burden. Soluble immunoregulatory proteins that function in lymphocyte activation or inhibition are elevated in PWH and associate with T-cell dysfunction, HIV persistence, and are predictive of comorbid outcomes. Here, we measured a panel of 35 circulating immunoregulatory proteins in 116 PWH with variations in CD4 T-cell counts (poor CD4 trajectory: <200 cells/µl, n = 34 or immune competent: CD4 >500 cells/µl, n = 82) by Luminex. Participants were enrolled in the AIDS Clinical Trials Group Longitudinal Linked Randomized Trials cohort, had initiated ART on enrollment, and had been on suppressive ART for 1 year. Using non-parametric analysis, we found that the levels of CD276, ICOSL, BAFF, OX40, galectin-1, and galectin-9 were significantly higher in PWH with poor CD4 trajectories compared to individuals with immune-competent CD4 T-cell count. Notably, in logistic models, ICOSL and OX40 remained significant after adjusting for age and baseline plasma HIV RNA. Furthermore, Extreme Gradient Boosting machine learning models comprising co-stimulatory and inhibitory checkpoint proteins yielded high accuracy in classification of individuals with poor CD4 trajectories. In summary, we identified a novel signature of circulating immunoregulatory proteins indicative of poor CD4 trajectories that may serve as potential targets to monitor and manage immune perturbations more accurately in PWH during suppressive ART. IMPORTANCE: It is essential to track immune perturbations related to insufficient CD4 T-cell recovery in PWH on suppressive ART as those with incomplete reconstitution are at a greater risk of non-AIDS-related morbidity and mortality. Several inflammatory soluble mediators have associated with poor immune reconstitution and adverse morbid outcomes in PWH, yet their implementation into routine clinical care to guide management remains inconsistent. Circulating immune checkpoint proteins have been linked to dysregulated immune pathways during suppressive ART and may serve as improved surrogate markers of clinical relevance. Here we investigate soluble lymphocyte-associated immunoregulatory proteins in virally suppressed PWH with no reported co-morbid outcomes and varying CD4 T-cell counts, to reveal underlying pathways that remain perturbed despite ART. This novel signature of immunoregulatory markers pertaining to poor CD4 T-cell trajectories uncover previously overlooked immune checkpoints as important targets for clinical monitoring of PWH in the setting of durable viral suppression by ART.

An in vitro set-up to study Pdr5-mediated substrate translocation.

Pdr5 is the most abundant ABC transporter in Saccharomyces cerevisiae and plays a major role in the pleiotropic drug resistance (PDR) network, which actively prevents cell entry of a large number of structurally unrelated compounds. Due to a high level of asymmetry in one of its nucleotide binding sites (NBS), Pdr5 serves as a perfect model system for asymmetric ABC transporter such as its medical relevant homologue Cdr1 from Candida albicans. In the past 30 years, this ABC transporter was intensively studied in vivo and in plasma membrane vesicles. Nevertheless, these studies were limited since it was not possible to isolate and reconstitute Pdr5 in a synthetic membrane system while maintaining its activity. Here, the functional reconstitution of Pdr5 in a native-like environment in an almost unidirectional inside-out orientation is described. We demonstrate that reconstituted Pdr5 is capable of translocating short-chain fluorescent NBD lipids from the outer to the inner leaflet of the proteoliposomes. Moreover, this transporter revealed its ability to utilize other nucleotides to accomplish transport of substrates in a reconstituted system. Besides, we were also able to estimate the NTPase activity of reconstituted Pdr5 and determine the kinetic parameters for ATP, GTP, CTP, and UTP.

Experimental Considerations for the Evaluation of Viral Biomolecular Condensates.

Biomolecular condensates are nonmembrane-bound assemblies of biological polymers such as protein and nucleic acids. An increasingly accepted paradigm across the viral tree of life is (a) that viruses form biomolecular condensates and (b) that the formation is required for the virus. Condensates can promote viral replication by promoting packaging, genome compaction, membrane bending, and co-opting of host translation. This review is primarily concerned with exploring methodologies for assessing virally encoded biomolecular condensates. The goal of this review is to provide an experimental framework for virologists to consider when designing experiments to (a) identify viral condensates and their components, (b) reconstitute condensation cell free from minimal components, (c) ask questions about what conditions lead to condensation, (d) map these questions back to the viral life cycle, and (e) design and test inhibitors/modulators of condensation as potential therapeutics. This experimental framework attempts to integrate virology, cell biology, and biochemistry approaches.

Discovery and biosynthesis of non-canonical C16-terpenoids from Pseudomonas.

Biosynthesis of sodorifen with a unique C16-bicyclo[3.2.1]octene framework requires an S-adenosyl methionine-dependent methyltransferase SodC and terpene cyclase SodD. While bioinformatic analyses reveal a wide distribution of the sodCD genes organization in bacteria, their functional diversity remains largely unknown. Herein, two sodorifen-type gene clusters, pcch and pcau, from Pseudomonas sp. are heterologously expressed in Escherichia coli, leading to the discovery of two C16 terpenoids. Enzymatic synthesis of these compounds is achieved using the two (SodCD-like) pathway-specific enzymes. Enzyme assays using different combinations of methyltransferases and terpene synthases across the pcch, pcau, and sod pathways reveal a unifying biosynthetic mechanism: all three SodC-like enzymes methylate farnesyl pyrophosphate (FPP) with subsequent cyclization to a common intermediate, pre-sodorifen pyrophosphate. Structural diversification of this joint precursor solely occurs by the subsequently acting individual terpene synthases. Our findings expand basic biosynthetic understanding and structural diversity of unusual C16-terpenoids.

Pattern of Immune Reconstitution Post Allogeneic Stem Cell Transplant: Data From a Resource Constraint Country.

OBJECTIVE: To determine the Pattern of immune reconstitution (IR) post allogeneic stem cell transplant at six months. STUDY DESIGN: Prospective observational study. Place and duration of the study: This study was conducted at The Armed Forces Bone Marrow Transplant Centre (AFMBTC) Rawalpindi, Pakistan, from May 2022 to December 2022. METHODOLOGY: After approval from the institutional review board, informed/written consents were taken from patients. All patients (both genders, irrespective of age) undergoing allogeneic hematopoietic stem cell transplant were included in the study. Patients undergoing haplo-identical or autologous bone marrow transplants were excluded from the study. Innate immune reconstitution was checked by complete blood count and adaptive immune reconstitution at six months was checked lymphocyte subset analysis and serum immunoglobulin levels. Data was entered in pre-designed proforma and was analyzed using IBM Corp. Released 2017. IBM SPSS Statistics for Windows, Version 25.0. Armonk, NY: IBM Corp. RESULTS: This study analyzes 43 patients, including 67% (n=29) males. The median age at the time of HSCT was 11.19 years. Cellular and humoral reconstitution at six months after transplant was used to assess immune reconstitution. Innate immune reconstitution was checked by complete blood count for count recovery (Neutrophil engraftment), and adaptive immune reconstitution (cellular/humoral) at six months was checked lymphocyte subset analysis and serum immunoglobulin levels. By using chi-square, significant associations were found as pre-transplant condition regimen with CD4 (PChi= 0.001), GVHD prophylaxis with CD4 (PChi= 0.04), source of stem cells with CD19 (PChi= 0.008), patient-donor gender disparity with CD19 (PChi= 0.05), GVHD treatment low CD19 (PChi= 0.04), patient-donor relationship with IgA(PChi= 0.007), IgG (PChi= 0.001), and IgM (PChi= 0.001), gender of the patient with IgA (PChi= 0.04). CONCLUSION: Our data suggested that at post-transplant six months, there was adequate immune reconstitution except for CD4 and CD4:CD8 ratio. Therefore, post-transplant, six months in Allo-HSCT could be considered for immunization.

No increased risk of tuberculosis-related immune reconstitution inflammatory syndrome with integrase inhibitor-based antiretroviral therapy in people with HIV with profound immunosuppression.

INTRODUCTION: The issue of whether integrase inhibitors (INSTIs) may confer a higher risk of paradoxical tuberculosis-related immune reconstitution inflammatory syndrome (TB-IRIS) compared with other classes of antiretroviral in people with HIV with a profound level of immunosuppression remains insufficiently explored. We aimed to assess whether such a higher risk exists by examining a cohort of patients with TB-HIV initiating antiretroviral therapy (ART) in Hong Kong. METHODS: This was a retrospective review of 133 patients registered in the TB-HIV Registry of the Department of Health during the period 2014-2021. RESULTS: Sixteen of 70 patients (22.9%; 95% confidence interval [CI] 13.0-32.7) and 14 of 63 patients (22.2%; 95% CI 12.0-32.5) from the INSTI and non-INSTI groups experienced TB-IRIS (p = 0.920). The median intervals between ART initiation and IRIS among patients from the two groups were similar (3 weeks [interquartile range IQR 2.0-7.8] vs. 4 weeks [IQR 2.0-5.1], p = 0.620). The proportion of patients requiring steroid therapy were similar, as were the hospitalization rates. There was no IRIS-related death in either group. The risk of TB-IRIS with INSTI versus non-INSTI was also similar in a stratified analysis in a subgroup of patients with a baseline CD4 count of <50 µL (10/33 [30.3%; 95% CI 14.6-46.0] vs. 10/22 [45.5%; 95% CI 24.7-66.3], p = 0.252) and another subgroup of patients with ART initiated within 4 weeks of anti-TB treatment (10/26 [38.5%; 95% CI 19.8-57.2] vs. 10/23 [43.5%; 95% CI 23.2-63.7], p = 0.721). CONCLUSION: Our cohort study did not offer support for an increased risk of TB-IRIS with INSTIs compared with non-INSTIs, even in severely immunocompromised people with HIV.

From Pancytopenia to Hyperleukocytosis, an Unexpected Presentation of Immune Reconstitution Inflammatory Syndrome in an Infant with Methylmalonic Acidemia.

A 2.5-month-old girl admitted for failure to thrive and severe pancytopenia was diagnosed with methylmalonic acidemia (MMA) secondary to transcobalamin II deficiency, an inborn error of vitamin B12 metabolism. Opportunistic Cytomegalovirus and Pneumocystis jirovecii pneumonia led to severe acute respiratory distress syndrome (ARDS) and immune reconstitution inflammatory syndrome (IRIS) after treatment initiation with vitamin B12 supplementation. In children with interstitial pneumonia-related ARDS, normal lymphocyte count should not delay invasive procedures required to document opportunistic infections. MMA can be associated with underlying lymphocyte dysfunction and vitamin B12 supplementation can fully reverse the associated immunodeficiency. IRIS may appear in highly treatment-responsive forms of pancytopenia in children and prompt treatment of dysregulated inflammation with high-dose corticosteroids should be initiated.

Practical Recommendations from the Gulf Region on the Therapeutic Use of Cladribine Tablets for the Management of Relapsing Multiple Sclerosis: Impact of the Latest Real-World Evidence on Clinical Practice.

Cladribine tablets (CladT), like alemtuzumab, acts as an immune reconstitution therapy. However, CladT is administered orally (alemtuzumab is given by infusion) and without the potential for serious side effects that limit the therapeutic use of alemtuzumab in multiple sclerosis (MS). Treatment with CladT, given initially as short courses of treatment 1 year apart, provides years of freedom from MS disease activity in responders to treatment. The appearance of mild or moderate MS disease activity after the initial 2 years of treatment may prompt careful follow-up or a further course of CladT, depending on the nature of the activity and individual circumstances. The appearance of severe MS disease activity requires a switch to an alternative high-efficacy disease-modifying treatment (DMT). The accumulating data from CladT-treated people with MS in real-world studies, including those with follow-up durations extending for years beyond the initial treatment, have demonstrated long-term freedom from MS disease activity in a good proportion of patients. This clinical experience has also confirmed that treatment with CladT is generally safe and well tolerated. The best time to prescribe a high-efficacy DMT is the subject of debate, with evidence that earlier versus later use of such agents may provide more effective long-term protection from disability progression. High-efficacy DMTs have traditionally been reserved for use in people with MS and high disease activity on presentation or breakthrough disease on one or more DMTs, as per the current product labels. The latest evidence from real-world studies suggests that CladT is effective and safe in DMT-naïve patients, including those with shorter disease duration.

Clinical characteristics and risk stratification for late-onset herpes zoster following allogeneic hematopoietic stem cell transplantation.

The incidence of herpes zoster (HZ) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients is significantly higher than that of the general public. Although routine antiviral prophylaxis is recommended, late-onset HZ has been highlighted, yet limited information is known about its clinical features and predictors. Here, we conducted a retrospective nested case-control study to identify patients with late-onset HZ, defined as a diagnosis of HZ after 1 year of transplantation, among allo-HSCT recipients between 2012 and 2017 at Peking University People's Hospital. Three controls were matched for each patient. A total of 201 patients developed late-onset HZ. Age over 20 years, absence of neutrophil engraftment by 14 days, mental disorders, immunosuppressant use at 1 year, and a peripheral CD4+/CD8+ ratio ≥0.5 at 1 year were independent risk factors, among which the CD4+/CD8+ ratio demonstrated good discriminative power for predicting late-onset HZ. For patients with a CD4+/CD8+ ratio <0.5, patient age, neutrophil engraftment time, mental disorders, and immunosuppressant use were potential risk factors. A stratification algorithm was accordingly established, classifying the transplant recipients into three risk groups. Whether the algorithm could facilitate the administration of posttransplant antiviral prophylaxis merits further validation.

Alpharetroviral Vector-Mediated Gene Therapy for IL7RA-Deficient Severe Combined Immunodeficiency.

Severe combined immunodeficiency (SCID) encompasses rare primary immunodeficiency disorders characterized by deficient T-cell development, which leads to a severely compromised immune system and susceptibility to life-threatening infections. Among SCID subtypes, IL7RA-SCID is caused by mutations in the interleukin 7 receptor alpha chain (IL7RA) and represents a significant subset of patients with limited treatment options. This study investigated the efficacy of a self-inactivating (SIN) alpharetroviral vector (ARV) engineered to deliver a codon-optimized IL7RA cDNA to restore T-cell development in Il7r-knockout mice. We compared the elongation factor 1 alpha short (EFS) promoter and the lymphoid-restricted Lck promoter for their ability to drive IL7RA expression and found that the EFS promoter enabled robust and sustained IL7RA expression that led to the functional rescue of T-lymphopoiesis in vitro and in vivo. Conversely, though effective in vitro, the Lck promoter failed to produce viable T-cell populations in vivo. Our results highlight the potential of using SIN-ARVs as a gene therapy (GT) strategy for treating IL7RA-SCID. Importantly, sustained production of T-lymphocytes was found in both primary and secondary transplant recipient animals with no adverse effects, supporting the safety and feasibility of this approach. Overall, this study provides valuable insights into the development of GT for IL7RA-SCID and underscores the clinical potential of an EFS-driven SIN-ARV to restore IL7RA-deficient immune function.

Reconstitution of the Melibiose Permease of Salmonella enterica serovar Typhimurium (MelBSt) into Lipid Nanodiscs.

Membrane proteins play critical roles in cell physiology and pathology. The conventional way to study membrane proteins at protein levels is to use optimal detergents to extract proteins from membranes. Identification of the optimal detergent is tedious , and in some cases, the protein functions are compromised. While this detergent-based approach has produced meaningful results in membrane protein research, a lipid environment should be more suitable to recapture the protein's native folding and functions. This protocol describes how to prepare amphipathic membrane scaffold-proteins (MSPs)-based nanodiscs of a cation-coupled melibiose symporter of Salmonella enterica serovar Typhimurium (MelBSt), a member of the major facilitator superfamily. MSPs generate nano-assemblies containing membrane proteins surrounded by a patch of native lipids to better preserve their native conformations and functions. This protocol requires purified membrane protein in detergents, purified MSPs in solution, and detergent-destabilized phospholipids. The mixture of all three components at specific ratios is incubated in the presence of Bio-Beads SM-2 resins, which absorb all detergent molecules, allowing the membrane protein to associate with lipids surrounded by the MSPs. By reconstituting the purified membrane proteins back into their native-like lipid environment, these nanodisc-like particles can be directly used in cryo-EM single-particle analysis for structure determination and other biophysical analyses. It is noted that nanodiscs may potentially limit the dynamics of membrane proteins due to suboptimal nanodisc size compared to the native lipid bilayer. Key features • This protocol was built based on the method originally developed by Sligar et al. [1] and modified for a specific major facilitator superfamily transporter • This protocol is robust and reproducible • Lipid nanodiscs can increase membrane protein stability, and reconstituted transporters in lipid nanodiscs can regain function if their function is compromised using detergents • The reconstituted lipids nanodisc can be used for cryo-EM single-particle analysis.