Presence of HLA-DR Molecules and HLA-DRB1 mRNA in Circulating CD4(+) T Cells

Association of Leukocyte Subpopulations Identified by Flow Cytometry with Outcomes of Sepsis in a Respiratory Intensive Care Unit: An Observational Study

INTRODUCTION

The dysregulated host immune response in sepsis is orchestrated by peripheral blood leukocytes. This study explored the associations of the peripheral blood leukocyte subpopulations with early clinical deterioration and mortality in sepsis.

METHODS

We performed a prospective observational single-center study enrolling adult subjects with sepsis within 48 h of hospital admission. Peripheral blood flow cytometry was performed for the patients at enrolment and after 5 days. The primary outcome was to explore the association between various leukocyte subpopulations at enrolment and early clinical deterioration [defined as an increase in the sequential organ failure assessment (SOFA) score between enrolment and day 5, or death before day 5]. Other pre-specified outcomes explored associations of leukocyte subpopulations at enrolment and on day 5 with in-hospital mortality.

RESULTS

A total of 100 patients, including 47 with septic shock were enrolled. The mean (SD) age of the patients was 53.99 (14.93) years. Among them, 26 patients had early clinical deterioration, whereas 41 died during hospitalization. There was no significant association between the leukocyte subpopulations at enrolment and early clinical deterioration on day 5. On multivariate logistic regression, a reduced percentage of CD8 + CD25+ T-cells at enrolment was associated with in-hospital mortality [odds ratio (OR), 0.82 (0.70-0.97); p-value = 0.02]. A reduced lymphocyte percentage on day 5 was associated with in-hospital mortality [OR, 0.28 (0.11-0.69); p-value = 0.01]. In a post-hoc analysis, patients with "very early" deterioration within 48 h had an increased granulocyte CD64 median fluorescent intensity (MFI) [OR, 1.07 (1.01-1.14); p-value = 0.02] and a reduced granulocyte CD16 MFI [OR, 0.97 (0.95-1.00); p-value = 0.04] at enrolment.

CONCLUSIONS

None of the leukocyte subpopulations showed an association with early clinical deterioration at day 5. Impaired lymphocyte activation and lymphocytopenia indicative of adaptive immune dysfunction may be associated with in-hospital mortality.

New Enhancing MRI Lesions Associate with IL-17, Neutrophil Degranulation and Integrin Microparticles: Multi-Omics Combined with Frequent MRI in Multiple Sclerosis

BACKGROUND

Blood-barrier (BBB) breakdown and active inflammation are hallmarks of relapsing multiple sclerosis (RMS), but the molecular events contributing to the development of new lesions are not well explored. Leaky endothelial junctions are associated with increased production of endothelial-derived extracellular microvesicles (EVs) and result in the entry of circulating immune cells into the brain. MRI with intravenous gadolinium (Gd) can visualize acute blood-barrier disruption as the initial event of the evolution of new lesions.

METHODS

Here, weekly MRI with Gd was combined with proteomics, multiplex immunoassay, and endothelial stress-optimized EV array to identify early markers related to BBB disruption. Five patients with RMS with no disease-modifying treatment were monitored weekly using high-resolution 3T MRI scanning with intravenous gadolinium (Gd) for 8 weeks. Patients were then divided into three groups (low, medium, or high MRI activity) defined by the number of new, total, and maximally enhancing Gd-enhancing lesions and the number of new FLAIR lesions. Plasma samples taken at each MRI were analyzed for protein biomarkers of inflammation by quantitative proteomics, and cytokines using multiplex immunoassays. EVs were characterized with an optimized endothelial stress EV array based on exosome surface protein markers for the detection of soluble secreted EVs.

RESULTS

Proteomics analysis of plasma yielded quantitative information on 208 proteins at each patient time point (n = 40). We observed the highest number of unique dysregulated proteins (DEPs) and the highest functional enrichment in the low vs. high MRI activity comparison. Complement activation and complement/coagulation cascade were also strongly overrepresented in the low vs. high MRI activity comparison. Activation of the alternative complement pathway, pathways of blood coagulation, extracellular matrix organization, and the regulation of TLR and IGF transport were unique for the low vs. high MRI activity comparison as well, with these pathways being overrepresented in the patient with high MRI activity. Principal component analysis indicated the individuality of plasma profiles in patients. IL-17 was upregulated at all time points during 8 weeks in patients with high vs. low MRI activity. Hierarchical clustering of soluble markers in the plasma indicated that all four MRI outcomes clustered together with IL-17, IL-12p70, and IL-1β. MRI outcomes also showed clustering with EV markers CD62E/P, MIC A/B, ICAM-1, and CD42A. The combined cluster of these cytokines, EV markers, and MRI outcomes clustered also with IL-12p40 and IL-7. All four MRI outcomes correlated positively with levels of IL-17 (p < 0.001, respectively), and EV-ICAM-1 (p < 0.0003, respectively). IL-1β levels positively correlated with the number of new Gd-enhancing lesions (p < 0.01), new FLAIR lesions (p < 0.001), and total number of Gd-enhancing lesions (p < 0.05). IL-6 levels positively correlated with the number of new FLAIR lesions (p < 0.05). Random Forests and linear mixed models identified IL-17, CCL17/TARC, CCL3/MIP-1α, and TNF-α as composite biomarkers predicting new lesion evolution.

CONCLUSIONS

Combination of serial frequent MRI with proteome, neuroinflammation markers, and protein array data of EVs enabled assessment of temporal changes in inflammation and endothelial dysfunction in RMS related to the evolution of new and enhancing lesions. Particularly, the Th17 pathway and IL-1β clustered and correlated with new lesions and Gd enhancement, indicating their importance in BBB disruption and initiating acute brain inflammation in MS. In addition to the Th17 pathway, abundant protein changes between MRI activity groups suggested the role of EVs and the coagulation system along with innate immune responses including acute phase proteins, complement components, and neutrophil degranulation.

HLA-DR Helps to Differentiate Erythrodermic Cutaneous T-cell Lymphoma from Erythrodermic Inflammatory Dermatoses in Flow Cytometry

Differential diagnosis of erythroderma is challenging in dermatology, especially in differentiating erythrodermic cutaneous T-cell lymphoma from erythrodermic inflammatory dermatoses. This study retrospectively reviewed the peripheral blood flow cytometric results of 73 patients diagnosed with erythroderma at Peking University First Hospital from 2014 to 2019. The flow cytometry antibody panel included white blood cell markers, T-cell markers, B-cell markers, T-cell activation markers, and T helper cell differentiation markers. Features of the cell surface antigens were compared between 34 patients with erythrodermic cutaneous T-cell lymphoma and 39 patients with erythrodermic inflammatory dermatoses. The percentage of HLA-DR+/CD4+T cells was the most pronounced marker to distinguish erythrodermic cutaneous T-cell lymphoma from erythrodermic inflammatory dermatoses, with a threshold of 20.85% (sensitivity 96.77%, specificity 70.37%, p = 0.000, area under the curve (AUC) 0.882), suggesting its potential capability in the differential diagnosis of erythrodermic cutaneous T-cell lymphoma from erythrodermic inflammatory dermatoses. Moreover, in contrast to erythrodermic inflammatory dermatoses, the percentage of Th17 cells was significantly downregulated in erythrodermic cutaneous T-cell lymphoma (p = 0.001), demonstrating a dysregulated immune environment in erythrodermic cutaneous T-cell lymphoma.

Analysis of urine differential proteins in patients with allergic rhinitis

Background

Allergic rhinitis (AR) is one of the most common clinical allergic diseases. Early diagnosis and medical intervention will benefit patients with allergic rhinitis. In this study, we focused on changes in urine proteomics in AR patients to investigate their potential clinical utility in AR diagnosis and evaluation.

Material and methods

TMT-labeled mass spectrometry-based proteomics was carried out to identify differentially expressed proteins (DEPs) in urine between allergic rhinitis patients and normal control groups. The molecular biological role of DEPs was investigated by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and protein-protein interaction (PPI) network analysis.

Results

Enrichment analysis showed that the differentially expressed proteins were mainly related to cell-cell adhesion, complement and coagulation cascades, peptidase activity regulation, MAP kinase activity, etc. Compared with the NC group, HLA-DRB1, WFDC12, and DEFA4, among the top ten up-regulated proteins in the urine of the AR group, were related to the biological process of the humoral immune response. Among the top 10 down-regulated proteins, GUSB, SQSTM1, and KIT are related to protein domain-specific binding in terms of molecular function.

Conclusions

We found differential protein changes between AR patients and normal subjects may be related to the pathophysiological changes of AR, which provides the possibility for further exploration of urinary proteomics biomarkers in the future.

Breast Cancer Patients: Who Would Benefit from Neoadjuvant Chemotherapies?

Neoadjuvant chemotherapy (NACT) was developed with the aims of shrinking tumors or stopping cancer cells from spreading before surgery. Unfortunately, not all breast cancer patients will benefit from NACT, and thus, patients must weigh the risks and benefits of treatment prior to the initiation of therapy. Currently, the data for predicting the efficacy of NACT is limited. Molecular testing, such as Oncotype DX, MammaPrint, and Curebest 95GC, have been developed to assist which breast cancer patients will benefit from the treatment. Patients with an increased level of Human Leukocyte Antigen-DR isotype, tumor-infiltrating lymphocytes, Fizzy-related protein homolog, and a decreased level of tumor-associated macrophages appear to benefit most from NACT.

HLA-DR+ CD45RA- Tregs and CD28- Treg-like cells: Potential immunologic biomarkers for reproductive aging

PROBLEM

This study aimed to identify subsets of regulatory T cells (Tregs) associated with ovarian aging and determine whether they can be used as markers of reproductive aging.

METHOD

This prospective cohort study was conducted among women of reproductive age. Basic physiological characteristics, reproductive hormones, Treg cell subsets, and correlations between these parameters were assessed. The POSEIDON criteria was used to identify women with low reproductive potential.

RESULTS

The percentages of HLA-DR⁺ CD45RA- Tregs and CD28- Treg-like cells significantly increased with age. Women between 40 and 49 years had significantly higher percentages of HLA-DR⁺ CD45RA- Tregs and CD28- Treg-like cells than those at 20-29, 30-34, and 35-39 years old. Age positively correlated with FSH levels and the percentages of HLA-DR⁺ CD45RA- Tregs and CD28- Treg-like cells, but inversely correlated with antral follicle count (AFC) and AMH levels. Interestingly, a positive correlation was found between the percentages of HLA-DR⁺ CD45RA- Tregs and FSH levels, whereas an inverse correlation was found between those of HLA-DR⁺ CD45RA- Tregs and AFC or AMH levels. Furthermore, a significant positive correlation was observed between the percentages of CD28- Treg-like cells and AFC. Based on POSEIDON criteria, women with the percentages of HLA-DR⁺ CD45RA- Tregs and CD28- Treg-like cells above reference value ranges were assigned to the low prognosis groups.

CONCLUSION

These findings suggest that HLA-DR⁺ CD45RA- Tregs and CD28- Treg-like cells can be used as immunologic markers of reproductive aging, which helps clinicians identify women with low reproductive potential and establish individualized therapeutic strategies. This article is protected by copyright. All rights reserved.

Atorvastatin restores imbalance of cluster of differentiation 4 (CD4)+ T cells in immune thrombocytopenia in vivo and in vitro

Immune thrombocytopenia (ITP) is an autoimmune haemorrhagic disease, in which the overactivation of T cells is crucial in the pathogenesis. Atorvastatin (AT), a lipid-lowering medicine, has shown promising immunomodulatory effects in certain inflammatory conditions. However, the immunoregulatory role of AT in ITP remains elusive. To investigate the effect of AT in the treatment of ITP, cluster of differentiation 4 (CD4)⁺ T cells were isolated from patients with ITP and cultured with different dosages of AT. We found that AT significantly inhibited cell proliferation, led to cell cycle arrest, induced apoptosis, and repressed the activation of CD4⁺ T cells in vitro. ITP murine models were then established, and results showed that AT treatment led to faster recovery of the platelet count to normal and exhibited comparable immunomodulatory function. Furthermore, we found the phosphorylation of mammalian target of rapamycin (mTOR), protein kinase B (AKT) and extracellular signal-regulated kinase (ERK), as well as activation of rat sarcoma virus (RAS) were all reduced dramatically after AT treatment in vitro. In conclusion, our present study demonstrated that AT could reinstate the functions of CD4⁺ T cells by inhibiting the excessive activation, proliferation, and survival of CD4⁺ T cells in ITP via the RAS/mitogen-activated protein kinase kinase (MEK)/ERK and the mTOR/phosphatidylinositol-3 kinase (PI3K)/AKT pathway. Therefore, we propose that AT could be used as a potential therapeutic option for ITP by restoring the over-activated cellular immunity.

Allogeneic CAR T Cells: An Alternative to Overcome Challenges of CAR T Cell Therapy in Glioblastoma

Chimeric antigen receptor (CAR) T cell therapy has emerged as one of the major breakthroughs in cancer immunotherapy in the last decade. Outstanding results in hematological malignancies and encouraging pre-clinical anti-tumor activity against a wide range of solid tumors have made CAR T cells one of the most promising fields for cancer therapies. CAR T cell therapy is currently being investigated in solid tumors including glioblastoma (GBM), a tumor for which survival has only modestly improved over the past decades. CAR T cells targeting EGFRvIII, Her2, or IL-13Rα2 have been tested in GBM, but the first clinical trials have shown modest results, potentially due to GBM heterogeneity and to the presence of an immunosuppressive microenvironment. Until now, the use of autologous T cells to manufacture CAR products has been the norm, but this approach has several disadvantages regarding production time, cost, manufacturing delay and dependence on functional fitness of patient T cells, often reduced by the disease or previous therapies. Universal “off-the-shelf,” or allogeneic, CAR T cells is an alternative that can potentially overcome these issues, and allow for multiple modifications and CAR combinations to target multiple tumor antigens and avoid tumor escape. Advances in genome editing tools, especially via CRISPR/Cas9, might allow overcoming the two main limitations of allogeneic CAR T cells product, i.e., graft-vs.-host disease and host allorejection. Here, we will discuss how allogeneic CAR T cells could allow for multivalent approaches and alteration of the tumor microenvironment, potentially allowing the development of next generation therapies for the treatment of patients with GBM.

Detection of Nonhematologic Neoplasms by Routine Flow Cytometry Analysis

OBJECTIVES

We investigated the ability of routine flow cytometry (FC) to detect nonhematologic neoplasms (non-HN) using antibody panels routinely used for the diagnosis of hematologic neoplasms.

METHODS

FC analyses of 4,000 various diagnostic samples were retrospectively reviewed to identify cases in which an aberrant, viable CD45-negative, nonhematologic neoplastic population was detected by FC panels designed to evaluate hematologic neoplasms.

RESULTS

A total of 57 (1.4%) diverse non-HNs were identified, representing neuroendocrine tumors (33/57) and carcinomas (9/57), as well as other malignancies (15/57) such as sarcoma and melanoma. The majority of neoplasms were positive for at least one antibody, typically CD56 (43/51, 84.3%), followed by CD117 (15/34, 44.1%) and CD138 (6/33, 18.2%).

CONCLUSIONS

Our findings highlight the importance of carefully inspecting CD45-negative events to identify non-HNs by routine FC analysis. This can help expedite further downstream immunophenotypic analysis of specimens and triage samples for appropriate genetic and molecular studies.

Influence of nasal polyp tissue on the differentiation and activation of T lymphocytes in a co-culture system

T cell subpopulations in nasal polyps differ from peripheral lymphocytes in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). However, little is known about the modulatory influence of the inflamed nasal polyp epithelial cells on the phenotype of the T cells. The aim of the present study was to assess this interaction. Tissue and blood samples were collected from 16 patients undergoing paranasal sinus surgery. Polypoid tissue was cultured under air-liquid interface conditions. Subsequently, cluster of differentiation (CD)3/CD28 activated peripheral lymphocytes from the same patients were added. After 3 days lymphocytes were separated from co-culture and analyzed by multicolor flow cytometry. Additionally, cytokine expression of the polyp tissue was measured using a human T helper cell (TH)1/T_H2/T_H17 antibody array. Viability staining of CD3⁺ lymphocytes detected fewer apoptotic cells under co-culture conditions compared with in mono-culture. There was a significantly higher frequency of CD4⁺ and CD8⁺ T cells in the co-culture system than in PBMC culture alone. Human leukocyte antigen (HLA)-DR isotype was significantly downregulated on co-cultured CD3⁺ lymphocytes and CD3⁺CD4⁺ T cells compared with the mono-cultured counterparts. Conventional Forkhead box P3^- memory CD4⁺ T cells and activated regulatory T cells increased in frequency, and resting regulatory T cells decreased in the co-culture. Cytokine analysis identified expression of interleukin (IL)-6, IL-6 receptor, granulocyte-macrophage colony-stimulating factor, transforming growth factor-β and macrophage inflammatory protein-3 in the polyp tissue. In summary, the present study performed a comparison between peripheral lymphocytes cultured with and without nasal polyp tissue cells was performed. The downregulation of HLA and the differentiation of T_reg and T_conv by nasal polypoid tissue on PBMCs was demonstrated. Interestingly, the in vivo downregulation of HLA-DR on CD3⁺ lymphocytes, as reported previously, was confirmed in vitro. The inhibitory effect of polypoid tissue on the activation of lymphocytes is a possible pathogenic mechanism underlying CRSwNP.

Hypomethylation of HLA-DRB1 and its clinical significance in psoriasis

Increasing evidences indicate that the abnormal DNA methylation is involved in the pathogenesis of psoriasis. A number of SNPs in HLA-DRB1 have been found being associated with the risk of psoriasis, however it is unclear that metylation status within HLA-DRB1 in psoriasis. Here, DNA and RNA were obtained from epidermis of 56 patients with plaque psoriasis and 28 healthy volunteers served as the control group. For the first time, we discovered mean methylation rate for HLA-DRB1 is 52.2%, 64.3% and 68.1% in epidermis from psoriatic lesions, psoriatic non-lesions and healthy controls, respectively. HLA-DRB1 methylation in psoriatic lesions is significantly lower than in psoriatic non-lesions (t = 13.077, p < 0.001). However, there is no significant difference for HLA-DRB1 methylation between in psoriatic non-lesions and in healthy controls (t = 1.046, p = 0.299). HLA-DRB1 methylation in psoriatic lesions is negatively correlated to PASI score (r = -0.431, p = 0.001). HLA-DRB1 methylation in psoriatic lesions of the patients with onset age≤18 years is significantly lower than the other patients (t = 3.968, p < 0.001). Meanwhile, HLA-DRB1 mRNA expression is significantly increased in psoriatic lesions comparing to psoriatic non-lesions (t = 12.119, p < 0.001). There are no significant difference for HLA-DRB1 mRNA expression between in psoriatic non-lesions and in healthy controls (t = 1.172, p = 0,245). Moreover, HLA-DRB1 mRNA expression is negatively associated with HLA-DRB1 methylation in psoriatic lesions (r = 0.932, p < 0.001). In conclusions, our results showed hypomethylation of HLA-DRB1 is associated with HLA-DRB1 mRNA expression and severity of the disease, indicating that hypomethylation of HLA-DRB1 may play roles in the pathogenesis of psoriasis.

Induction of a Regulatory Phenotype in CD3+ CD4+ HLA-DR+ T Cells after Allogeneic Mixed Lymphocyte Culture; Indications of Both Contact-Dependent and -Independent Activation

Although the observation of major histocompatibility complex II (MHCII) receptors on T cells is longstanding, the explanation for this occurrence remains enigmatic. Reports of an inducible, endogenous expression exist, as do studies demonstrating a protein acquisition from other cells by mechanisms including vesicle transfer. Irrespective of origin, the presence of the human MHCII isotype, human leukocyte antigen DR (HLA-DR), potentially identifies a regulatory T cell population. Using an allogeneic mixed lymphocyte culture (MLC) to induce an antigen-specific immune response, the role of antigen-presenting cells (APCs) for the presence of HLA-DR on cluster of differentiation 3(CD3)+ CD4+ T cells was evaluated. Moreover, a functional phenotype was established for these T cells. It was demonstrated that APCs were essential for HLA-DR on CD3+ CD4+ T cells. Additionally, a regulatory T cell phenotype was induced in CD3+ CD4+ HLA-DR+ responder T cells with an expression of CD25, CTLA-4, CD62L, PD-1, and TNFRII. This phenotype was induced both with and without physical T cell:APC contact, which could reveal novel indications about its functionality. To further investigate contact-independent communication, a phenotype of the small cell-derived vesicles from the MLCs was determined. Yet heterogeneous, this vesicle phenotype displayed contact-dependent differences, providing clues about their intended function in cellular communication.