Blood Counterparts Research Articles

Comparative analysis of human gut- and blood-derived mononuclear cells: contrasts in function and phenotype.

Alterations in the gut immune system have been implicated in various diseases.The challenge of obtaining gut tissues from healthy individuals, commonly performed via surgical explants, has limited the number of studies describing the phenotype and function of gut-derived immune cells in health. Here, by means of recto-sigmoid colon biopsies obtained during routine care (colon cancer screening in healthy adults), the phenotype and function of immune cells present in the gut were described and compared to those found in blood. The proportion of CD4+, CD8+, MAIT, γδ+ T, and NK cells phenotype, expression of integrins, and ability to produce cytokine in response to stimulation with PMA and ionomycin. T cells in the gut were found to predominantly have a memory phenotype as compared to T cells in blood where a naïve phenotype predominates. Recto-sigmoid mononuclear cells also had higher PD-1 and Ki67 expression. Furthermore, integrin expression and cytokine production varied by cell type and location in blood vs. gut. These findings demonstrate the differences in functionality of these cells when compared to their blood counterparts and validate previous studies on phenotype within gut-derived immune cells in humans (where cells have been obtained through surgical means). This study suggests that recto-sigmoid biopsies collected during colonoscopy can be a reliable yet more accessible sampling method for follow up of alterations of gut derived immune cells in clinical settings.

Single-cell profiling reveals kidney CD163+ dendritic cell participation in human lupus nephritis

ObjectivesThe current work aimed to provide a comprehensive single-cell landscape of lupus nephritis (LN) kidneys, including immune and non-immune cells, identify disease-associated cell populations and unravel their participation within the...

Aberrant follicular regulatory T cells associate with immunoglobulin hyperproduction in nasal polyps with ectopic lymphoid tissues

Ectopic lymphoid tissues (eLTs) and associated follicular helper T (TFH) cells contribute to local immunoglobulin hyperproduction in nasal polyps (NPs). Follicular regulatory T (TFR) cells in secondary lymphoid organs counteract TFH cells and suppress immunoglobulin production; however, the presence and function of TFR cells in eLTs in peripheral diseased tissues remain poorly understood. We sought to investigate the presence, phenotype, and function of TFR cells in NPs. The presence, abundance, and phenotype of TFR cells in NPs were examined using single-cell RNA sequencing, immunofluorescence staining, and flow cytometry. Sorted polyp and circulating T-cell subsets were cocultured with autologous circulating naïve B cells, and cytokine and immunoglobulin production were measured by ELISA. TFR cells were primarily localized within eLTs in NPs. TFR cell frequency and TFR cell/TFH cell ratio were decreased in NPs with eLTs compared with NPs without eLTs and control inferior turbinate tissues. TFR cells displayed an overlapping phenotype with TFH cells and FOXP3+ regulatory T cells in NPs. Polyp TFR cells had reduced CTLA-4 expression and decreased capacity to inhibit TFH cell-induced immunoglobulin production compared with their counterpart in blood and tonsils. Blocking CTLA-4 abolished the suppressive effect of TFR cells. Lower vitamin D receptor expression was observed on polyp TFR cells compared with TFR cells in blood and tonsils. Vitamin D treatment upregulated CTLA-4 expression on polyp TFR cells and restored their suppressive function invitro. Polyp TFR cells in eLTs have decreased CLTA-4 and vitamin D receptor expression and impaired capacity to suppress TFH cell-induced immunoglobulin production, which can be reversed by vitamin D treatment invitro.

Covid-19 Induced Neonatal Immunity

December 2019 a few cases of severe pneumonia was detected in Wuhan, China The patients were exhibiting symptoms like fever, dry cough, sore throat, breathlessness, and fatigue. investigation employing next generation sequencing and phylogenetic analysis led to the identification of the causative agent of this respiratory disease, a novel coronavirus 2019 [1]. As more cases started to appear around the world, on February 11, 2020, the World Health Organization assigned a name, Corona Virus Disease 2019 or COVID-19, to the disease and declared it a pandemic on March 11, 2020. The virus was renamed from 2019-nCoV to SARS-CoV-2 by the International Committee on Taxonomy of Viruses on the basis of its genetic similarity to a previously known coronavirus, Severe Acute Respiratory Syndrome Coronavirus(SARS-CoV) [2].Coronavirus 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome SARS-CoV- 2, has resulted in more than six million deaths and has infected over 500 million people as of July 19, 2022 [3]. SARS-CoV-2 infected pregnant women are at increased risk of severe COVID- 19 than non-pregnant women and have a higher risk of adverse pregnancy outcomes like intrauterine/fetal distress and preterm birth.The most severe outcomes of COVID-19 have been documented in geriatric individuals and pregnant women with chronic diseases, including hypertension, diabetes, and cardiopulmonary problems [4]. Newborn protection from infection is primarily dependent on neonatal innate immune responses and maternally derived, transplacentally acquired antibodies. The extent to which maternal antibodies produced in response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy cross the placenta is important for understanding potential neonatal protection from coronavirus disease 2019 (COVID- 19.We investigated humoral responses to SARS-CoV-2 inmaternalandcordbloodpairedsamples in the case of natural infection during late second and third trimesters of pregnancy recruited at TSMU Department of Obstetrics and Gynecology TSMU First University Clinic. Georgia, Tbilisi. Maternal nasopharyngeal swabs were collected for SARS-CoV-2 detection by rate-PCR for confirmation of viral infection at the admission to the hospital. We measured IgG to spike (S) receptor-binding domain and nucleocapsid (N) Sixty-eight pregnant women SARS-CoV-2 positive by rRT- PCR were included in our study. Serology samples of maternal and cord blood has been collected immediately after delivery. For study design we have determined inclusion and exclusion criteria’s. General medical data of patients included in the study have been collected from medical records and Informed written consent was obtained from all the patients involved in the study. SARS-CoV-2, IgG has been detected by ELISA method.infected mothers had increased levels of virus-specific antibodies maternal IgG levels showed positive correlations with their counterparts in cord blood. PCR positive mothers showed stronger effect when infection was closer to delivery.Our results show that SARS- CoV-2 infection during the second and third trimester of pregnancy induces antibody response at delivery and causes lower level of the SARS-CoV-2-specific IgG trans placental transfer, when the infection is closer to delivery.

In-Depth Proteomic Map of Innate Lymphoid Cells from Healthy Human Skin and Blood

Innate lymphoid cells (ILCs) are essential players in the skin-associated immune system, nevertheless little is known about their proteomes and proteomic diversity. In this study, we describe about 6,600 proteins constitutively expressed by ILC2s and ILC3s from healthy human skin and blood using state-of-the-art proteomics. Although the vast majority of proteins was expressed by both ILC subsets and in both compartments, the skin ILC2s and ILC3s were more distinct than their counterparts in blood. Only skin ILC3s expressed uniquely detected proteins. Our in-depth proteomic datasetallowed us to define the cluster of differentiation marker profiles of the ILC subsets, explore distribution and abundance of proteins known to have immunological functions, as well as identify subset-specific proteins that have not previously been implicated in ILC biology. Taken together, our analyses substantially expand understanding of the protein expression signatures of ILC subsets. Going forward, these proteomic datasets will serve as valuable resources for future studies of ILC biology.

Cord blood-derived Vδ2+ and Vδ2- T cells acquire differential cell state compositions upon in vitro expansion.

Human cord blood-derived γδ T cells (CBγδ) display a highly diverse TCRγδ repertoire and have a unique subtype composition different from fetal or adult peripheral blood counterparts. We expanded CBγδ in vitro using an irradiated Epstein-Barr virus-transformed feeder cell-based modified rapid expansion protocol (REP). Single-cell RNA sequencing tracked progressive differentiation of naïve CBγδ into cells expressing neoantigen-reactive tumor-infiltrating lymphocyte as well as tissue-resident memory precursor-like and antigen-presenting cell-like gene signatures. TCRγδ clonal tracing revealed a bias toward cytotoxic effector differentiation in a much larger proportion of Vδ2- clones compared to Vδ2+ clones, resulting in the former being more cytotoxic at the population level. These clonotype-specific differentiation dynamics were not restricted to REP and were recapitulated upon secondary nonviral antigen stimulations. Thus, our data showed intrinsic cellular differences between major subtypes of human γδ T cells already in operation at early postnatal stage and highlighted key areas of consideration in optimizing cell manufacturing processes.

The role of WNT and IL-1 signaling in osteoarthritis: therapeutic implications for platelet-rich plasma therapy.

Different from inflammatory arthritis, where biologicals and targeted synthetic molecules have revolutionized the disease course, no drug has demonstrated a disease modifying activity in osteoarthritis, which remains one of the most common causes of disability and chronic pain worldwide. The pharmacological therapy of osteoarthritis is mainly directed towards symptom and pain relief, and joint replacement is still the only curative strategy. Elucidating the disease pathophysiology is essential to understand which mechanisms can be targeted by innovative therapies. It has extensively been demonstrated that aberrant WNT and IL-1 signaling pathways are responsible for cartilage degeneration, impaired chondrocyte metabolism and differentiation, increased extracellular matrix degradation, and altered subchondral bone homeostasis. Platelet-rich plasma is an autologous blood derivative containing a concentration of platelets that is much higher than the whole blood counterpart and has shown promising results in the treatment of early knee osteoarthritis. Among the proposed mechanisms, the modulation of WNT and IL-1 pathways is of paramount importance and is herein reviewed in light of the proposed regenerative approaches.

Neoantigen-specific CD8 T cells with high structural avidity preferentially reside in and eliminate tumors

The success of cancer immunotherapy depends in part on the strength of antigen recognition by T cells. Here, we characterize the T cell receptor (TCR) functional (antigen sensitivity) and structural (monomeric pMHC-TCR off-rates) avidities of 371 CD8 T cell clones specific for neoantigens, tumor-associated antigens (TAAs) or viral antigens isolated from tumors or blood of patients and healthy donors. T cells from tumors exhibit stronger functional and structural avidity than their blood counterparts. Relative to TAA, neoantigen-specific T cells are of higher structural avidity and, consistently, are preferentially detected in tumors. Effective tumor infiltration in mice models is associated with high structural avidity and CXCR3 expression. Based on TCR biophysicochemical properties, we derive and apply an in silico model predicting TCR structural avidity and validate the enrichment in high avidity T cells in patients’ tumors. These observations indicate a direct relationship between neoantigen recognition, T cell functionality and tumor infiltration. These results delineate a rational approach to identify potent T cells for personalized cancer immunotherapy.

Circulating CD133+/–CD34– Have Increased c-MYC Expression in Myeloproliferative Neoplasms

Myeloproliferative neoplasms (MPNs) are hematopoietic stem cell (HSC)-originated diseases with clonal myeloproliferation. The constitutive activation of the JAK/STAT pathway is frequently detected in patients with Philadelphia chromosome-negative (Ph–) MPNs with an acquired JAK2V617F mutation. The c-MYC proto-oncogene is associated with malignant growth and cellular transformation, and JAK2V617F was previously shown to induce constitutive expression of c-MYC. This study examines the expressional profile of c-MYC in Ph– MPNs with JAK2V617F and highlights its hierarchical level of activation in circulating hematopoietic stem/progenitor cell (HSPC) subgroups. Mononuclear cells (MNCs) of Ph– MPNs were fluorochrome-labeled in situ with wild-type (wt) JAK2 or JAK2V617F mRNA gold nanoparticle technology and sorted simultaneously. Isolated populations of JAK2wt or JAK2V617F were evaluated for their c-MYC expressions. The MNCs of 14 Ph– MPNs were further isolated for the study of HSPC subgroups regarding their CD34 and CD133 expressions, evaluated for the presence of JAK2V617F, and compared to cord blood (CB) counterparts for the expression of c-MYC. The mRNA-labeled gold nanoparticle-treated MNCs were determined to have the highest ratio of c-MYC relative fold-change expression in the biallelic JAK2V617F compartment compared to JAK2wt. The relative c-MYC expression in MNCs of MPNs was significantly increased compared to CB (p=0.01). The circulating HSPCs of CD133+/–CD34− MPNs had statistically significantly elevated c-MYC expression compared to CB. This is the first study of circulating CD133+/–CD34− cells in Ph– MPNs and it has revealed elevated c-MYC expression levels in HSCs/endothelial progenitor cells (HSCs/EPCs) and EPCs. Furthermore, the steady increase in the expression of c-MYC within MNCs carrying no mutations and monoallelic or biallelic JAK2V617F transcripts was notable. The presence of JAK2V617F with respect to c-MYC expression in the circulating HSCs/EPCs and EPCs of MPNs might provide some evidence for the initiation of JAK2V617F and propagation of disease. Further studies are needed to clarify the implications of increased c-MYC expression in such populations.

In Vitro Generation of Human Cross-Presenting Type 1 Conventional Dendritic Cells (cDC1s) and Plasmacytoid Dendritic Cells (pDCs).

Dendritic cells (DCs) represent one of the most important immune cell subsets in preventing the host from pathogen invasion by promoting both innate and adaptive immunity. Most research on human dendritic cells has focused on the easy-to-obtain dendritic cells derived in vitro from monocytes (MoDCs). However, many questions remain unanswered regarding the role of different dendritic cell types. The investigation of their roles in human immunity is hampered by their rarity and fragility, which especially holds true for type 1 conventional dendritic cells (cDC1s) and for plasmacytoid dendritic cells (pDCs). In vitro differentiation from hematopoietic progenitors emerged as a common way to produce different DC types, but the efficiency and reproducibility of these protocols needed to be improved and the extent to which the DCs generated in vitro resembled their in vivo counterparts required a more rigorous and global assessment. Here, we describe a cost-effective and robust in vitro differentiation system for the production of cDC1s and pDCs equivalent to their blood counterparts, from cord blood CD34+ hematopoietic stem cells (HSCs) cultured on a stromal feeder layer with a combination of cytokines and growth factors.

Distinct populations of eosinophils in the human thymus with capacity to modulate thymocyte maturation.

Local differentiation of eosinophil precursors occurs in the human thymus. Thymic eosinophils are often positioned in the corticomedullary junction between the CD4+ CD8+ double-positive (DP) thymocytes and the CD4+ or CD8+ single-positive (SP) thymocytes. The aims of this study were to (1) determine if there are distinct thymic eosinophil populations that differ from the blood eosinophil populations and (2) evaluate the capacity of thymic eosinophils to promote the development of SP thymocytes from DP thymocytes. Thymic and blood eosinophils from thymectomized infants (n=7) were compared regarding the expression of 34 molecules using cytometry by time-of-flight (CyTOF). In addition, FACS-sorted thymic eosinophils were co-cultured with autologous CD3/CD28-stimulated DP, CD4 SP, and CD8 SP thymocytes and analysed by flow cytometry and CyTOF. X-shift clustering analysis and viSNE dimensionality reduction were performed. Seven eosinophil populations were identified within the blood and thymus, respectively, five of which were specific for either tissue. Whereas the blood eosinophil populations varied between individuals, the thymic eosinophil populations were more uniform. The eosinophil-thymocyte co-cultures resulted in (1) an increase in CD4 SP thymocytes when eosinophils were cultured with DP thymocytes, (2) decreased frequency of CD8 SP thymocytes when these were cultured with eosinophils, and (3) a more mature thymic phenotype when eosinophils were cultured with CD4 SP thymocytes. Thymic eosinophils are a specialized population of eosinophils with a distinct phenotype that separates them from their blood counterparts, and in vitro they appear to favour CD4 SP thymocyte development to the detriment of CD8 SP thymocytes.

Maternal and neonatal immune response to SARS-CoV-2, IgG transplacental transfer and cytokine profile.

SARS-CoV-2 infected pregnant women are at increased risk of severe COVID-19 than non-pregnant women and have a higher risk of adverse pregnancy outcomes like intrauterine/fetal distress and preterm birth. However, little is known about the impact of SARS-CoV-2 infection on maternal and neonatal immunological profiles. In this study, we investigated the inflammatory and humoral responses to SARS-CoV-2 in maternal and cord blood paired samples. Thirty-six pregnant women were recruited at delivery at Hospital Sant Joan de Déu, Barcelona, Spain, between April-August 2020, before having COVID-19 available vaccines. Maternal and pregnancy variables, as well as perinatal outcomes, were recorded in questionnaires. Nasopharyngeal swabs and maternal and cord blood samples were collected for SARS-CoV-2 detection by rRT-PCR and serology, respectively. We measured IgM, IgG and IgA levels to 6 SARS-CoV-2 antigens (spike [S], S1, S2, receptor-binding domain [RBD], nucleocapsid [N] full-length and C-terminus), IgG to N from 4 human coronaviruses (OC43, HKU1, 229E and NL63), and the concentrations of 30 cytokines, chemokines and growth factors by Luminex. Mothers were classified as infected or non-infected based on the rRT-PCR and serology results. Sixty-four % of pregnant women were infected with SARS-CoV-2 (positive by rRT-PCR during the third trimester and/or serology just after delivery). None of the newborns tested positive for rRT-PCR. SARS-CoV-2 infected mothers had increased levels of virus-specific antibodies and several cytokines. Those with symptoms had higher cytokine levels. IFN-α was increased in cord blood from infected mothers, and in cord blood of symptomatic mothers, EGF, FGF, IL-17 and IL-15 were increased, whereas RANTES was decreased. Maternal IgG and cytokine levels showed positive correlations with their counterparts in cord blood. rRT-PCR positive mothers showed lower transfer of SARS-CoV-2-specific IgGs, with a stronger effect when infection was closer to delivery. SARS-CoV-2 infected mothers carrying a male fetus had higher antibody levels and higher EGF, IL-15 and IL-7 concentrations. Our results show that SARS-CoV-2 infection during the third trimester of pregnancy induces a robust antibody and cytokine response at delivery and causes a significant reduction of the SARS-CoV-2-specific IgGs transplacental transfer, with a stronger negative effect when the infection is closer to delivery.

Bladder wash as an alternative urine specimen for postmortem toxicology

Urine is the preferred sample in postmortem forensic toxicology to provide evidence of antemortem drug use. However, there are many scenarios in which the bladder is voided or dehydrated prior to their autopsy. In these cases, it is possible to wash the bladder with saline and collect the bladder wash and any residual urine for drug screening and confirmation. The San Francisco Office of the Chief Medical Examiner (OCME) has made the collection of bladder washes at autopsy an option, typically when urine is not available. While bladder washes are not conventional, this study aims to determine its use as an alternative specimen in postmortem forensic toxicology. Laboratory analysis of drugs by LC-MS/MS methodologies and alcohol by HS-GC-FID, was performed. Data from the analyses of bladder wash samples collected at the OCME were analyzed to assess the efficiency of this alternative sample in comparison to urine by determining the identities of individual analytes and their metabolites. Authentic case results showed that bladder wash drug analyses have good sensitivity and selectivity to serve as an alternative specimen when urine is not available. These results are even more so if both individual analytes and metabolites comparisons are considered during data analysis. The bladder wash drug analysis data was also compared to blood analysis data from the OCME to determine if the two were complementary. While bladder wash and blood drug analyses have compatible selectivities, the sensitivity of bladder wash analyses are lower than their blood counterparts. Crucially, in cases where only a bladder wash is analyzed, the detected drugs may provide critical information to a forensic pathologist about the cause and manner of death that would have otherwise not been obtained. Simultaneous to this study, a two-part survey was sent via the NAME list serve to evaluate pathologists’ views of the use of bladder washes before and after reviewing the results of the bladder wash data. This study appears to indicate that standardizing the collection and analysis of bladder washes in postmortem toxicology will provide forensic pathologists with a comprehensive toxicological profile in cases where urine and/or other biological specimens are not available for collection and subsequent analysis. Overall, pathologists were responsive to adopting the practice of collecting bladder washes for toxicological analysis. Bladder washes can serve as an efficient and accurate alternative specimen when there is no urine available to analyze. They are also a reliable alternative specimen to analyze when other specimens, such as blood and vitreous humor, cannot be collected and toxicologically analyzed.

Human Hepatic CD56bright NK Cells Display a Tissue-Resident Transcriptional Profile and Enhanced Ability to Kill Allogenic CD8+ T Cells.

Liver-resident CD56brightCD16- natural killer (NK) cells are enriched in the human liver and are phenotypically distinct from their blood counterparts. Although these cells are capable of rapid cytotoxic effector activity, their functional role remains unclear. We hypothesise that they may contribute to immune tolerance in the liver during transplantation. RNA sequencing was carried out on FACS sorted NK cell subpopulations from liver perfusates (n=5) and healthy blood controls (n=5). Liver-resident CD56brightCD16+/- NK cells upregulate genes associated with tissue residency. They also upregulate expression of CD160 and LY9, both of which encode immune receptors capable of activating NK cells. Co-expression of CD160 and Ly9 on liver-resident NK cells was validated using flow cytometry. Hepatic NK cell cytotoxicity against allogenic T cells was tested using an in vitro co-culture system of liver perfusate-derived NK cells and blood T cells (n=10-13). In co-culture experiments, hepatic NK cells but not blood NK cells induced significant allogenic T cell death (p=0.0306). Allogenic CD8+ T cells were more susceptible to hepatic NK cytotoxicity than CD4+ T cells (p<0.0001). Stimulation of hepatic CD56bright NK cells with an anti-CD160 agonist mAb enhanced this cytotoxic response (p=0.0382). Our results highlight a role for donor liver NK cells in regulating allogenic CD8+ T cell activation, which may be important in controlling recipient CD8+ T cell-mediated rejection post liver-transplant.

Combined High-Throughput Approaches Reveal the Signals Driven by Skin and Blood Environments and Define the Tumor Heterogeneity in Sézary Syndrome.

Simple SummarySézary syndrome (SS) is a leukemic and incurable variant of cutaneous T-cell lymphoma characterized by the accumulation of neoplastic CD4+ lymphocytes in the blood, lymph nodes, and skin. With the exception of allogenic transplantation, no curative chance is available to treat SS, and it is a priority to find new therapies that target SS cells within all disease compartments. This review aims to summarize the more recent analyses conducted on skin- and blood-derived SS cells concurrently obtained from the same SS patients. The results highlighted that skin-SS cells were more active/proliferating with respect to matched blood SS cells that instead appeared quiescent. These data shed the light on the possibility to treat blood and skin SS cells with different compounds, respectively. Moreover, this review recaps the more recent findings on the heterogeneity of circulating SS cells that presented a series of novel markers that could improve diagnosis, prognosis and therapy of this lymphoma.Sézary syndrome (SS) is an aggressive variant of cutaneous t-cell lymphoma characterized by the accumulation of neoplastic CD4+ lymphocytes—the SS cells—mainly in blood, lymph nodes, and skin. The tumor spread pattern of SS makes this lymphoma a unique model of disease that allows a concurrent blood and skin sampling for analysis. This review summarizes the recent studies highlighting the transcriptional programs triggered by the crosstalk between SS cells and blood–skin microenvironments. Emerging data proved that skin-derived SS cells show consistently higher activation/proliferation rates, mainly driven by T-cell receptor signaling with respect to matched blood SS cells that instead appear quiescent. Biochemical analyses also demonstrated an hyperactivation of PI3K/AKT/mTOR, a targetable pathway by multiple inhibitors currently in clinical trials, in skin SS cells compared with a paired blood counterpart. These results indicated that active and quiescent SS cells coexist in this lymphoma, and that they could be respectively treated with different therapeutics. Finally, this review underlines the more recent discoveries into the heterogeneity of circulating SS cells, highlighting a series of novel markers that could improve the diagnosis and that represent novel therapeutic targets (GPR15, PTPN13, KLRB1, and ITGB1) as well as new genetic markers (PD-1 and CD39) able to stratify SS patients for disease aggressiveness.

Uterine Natural Killer Cells: A Rising Star in Human Pregnancy Regulation.

Uterine natural killer (uNK) cells are an immune subset located in the uterus. uNK cells have distinct tissue-specific characteristics compared to their counterparts in peripheral blood and lymphoid organs. Based on their location and the pregnancy status of the host, uNK cells are classified as endometrial NK (eNK) cells or decidua NK (dNK) cells. uNK cells are important in protecting the host from pathogen invasion and contribute to a series of physiological processes that affect successful pregnancy, including uterine spiral artery remodeling, fetal development, and immunity tolerance. Abnormal alterations in uNK cell numbers and/or impaired function may cause pregnancy complications, such as recurrent miscarriage, preeclampsia, or even infertility. In this review, we introduce recent advances in human uNK cell research under normal physiological or pathological conditions, and summarize their unique influences on the process of pregnancy complications or uterine diseases. Finally, we propose the potential clinical use of uNK cells as a novel cellular immunotherapeutic approach for reproductive disorders.

Common and Divergent Features of T Cells from Blood, Gut, and Genital Tract of Antiretroviral Therapy-Treated HIV+ Women.

T cells residing in mucosal tissues play important roles in homeostasis and defense against microbial pathogens. The gut and female reproductive tract (FRT) are both tolerogenic environments, but they differ in the kinds of foreign Ags they need to tolerate. How these different environments influence the properties of their T cells is poorly understood, but important for understanding women's health. We recruited antiretroviral therapy-suppressed women living with HIV who donated, within one visit, blood and tissue samples from the ileum, colon, rectosigmoid, endometrium, endocervix, and ectocervix. With these samples, we conducted 36-parameter cytometry by time of flight phenotyping of T cells. Although gut and FRT T cells shared features discriminating them from their blood counterparts, they also harbored features distinguishing them from one another. These included increased proportions of CD69+ T resident memory cells of the T effector memory phenotype, as well as preferential coexpression of CD69 and CD103, on the gut-derived cells. In contrast, CD69+CD103+ T resident memory CD8+ T cells from FRT, but not those from gut, preferentially expressed PD1. We further determined that a recently described population of CXCR4+ T inflammatory mucosal cells differentially expressed multiple other chemokine receptors relative to their blood counterparts. Our findings suggest that T cells resident in different tolerogenic mucosal sites take on distinct properties.

Overexpression of PD-1 and CD39 in tumor-infiltrating lymphocytes compared with peripheral blood lymphocytes in triple-negative breast cancer.

Growing evidence highlighted the primary role of the immune system in the disease course of triple-negative breast cancer (TNBC). The study aim was to investigate the expression of PD-1 and CD39 on CD4+ and CD8+ cells infiltrating tumor tissue compared to their counterparts in peripheral blood and explore its association with tumor characteristics, disease progression, and prognosis in females with TNBC. The study included 30 TNBC patients and 20 healthy controls. Cancer and normal breast tissue and peripheral blood samples were collected for evaluation of the expression of PD-1 and CD39 on CD4+ and CD8+T cells by flow cytometry. A marked reduction in the percentage of CD8+ T lymphocytes and a significant increase in the frequencies of CD4+ T lymphocytes and CD4+ and CD8+ T lymphocytes expressing PD1 and CD39 were evident in tumor tissue in comparison with the normal breast tissue. The DFS was inversely related to the cancer tissue PD1+CD8+ and CD39+CD8+ T lymphocytes. Almost all studied cells were significantly increased in the tumor tissue than in peripheral blood. Positive correlations were detected among peripheral PD1+CD4+T lymphocytes and each of cancer tissue PD1+CD4+, PD1+CD8+and CD39+CD8+T cells, and among peripheral and cancer tissue CD39+CD4+and CD39+CD8+ T cells. The CD39 and PD1 inhibitory pathways are synergistically utilized by TNBC cells to evade host immune response causing poor survival. Hence, combinational immunotherapy blocking these pathways might be a promising treatment strategy in this type of cancer.

Activation and Functional Alteration of Mucosal-Associated Invariant T Cells in Adult Patients With Community-Acquired Pneumonia.

Community-acquired pneumonia (CAP) remains the significant infectious cause of morbidity and mortality worldwide. Although mucosal-associated invariant T cells (MAIT) play roles in the pathogenesis of children CAP and ICU-associated pneumonia, their roles in adult CAP are largely unexplored. In this study, we investigated the frequency, phenotype, and function of MAIT cells in peripheral blood and bronchoalveolar lavage fluid (BALF) of adult CAP patients. Our data indicate that MAIT-cell frequency is profoundly lower in the peripheral blood of CAP patients compared to that in healthy individuals. Furthermore, the circulatory MAIT cells express higher levels of CD69 and PD-1 compared to those in healthy individuals. In BALF of CAP patients, MAIT-cell frequency is higher and MAIT cells express higher levels of CD69 and PD-1 compared to their matched blood counterparts. Levels of IL-17A and IFN-γ are increased in BALF of CAP patients compared to those in BALF of patients with pulmonary small nodules. The IL-17A/IFN-γ ratio is significantly positively correlated with MAIT frequency in BALF of CAP patients, suggesting a pathogenic role of MAIT-17 cells in CAP. Of note, blood MAIT-cell frequency in CAP patients is strongly negatively correlated with high-sensitivity C-reactive protein (hsCRP) and neutrophil count percentage in blood. The ability of circulating MAIT cells in CAP patients to produce IFN-γ is significantly impaired compared to those in healthy individuals. In summary, our findings suggest the possible involvement of MAIT cells in the immunopathogenesis of adult CAP.

Single-cell analysis of diverse immune phenotypes in malignant pleural effusion

The complex interactions among different immune cells have important functions in the development of malignant pleural effusion (MPE). Here we perform single-cell RNA sequencing on 62,382 cells from MPE patients induced by non-small cell lung cancer to describe the composition, lineage, and functional states of infiltrating immune cells in MPE. Immune cells in MPE display a number of transcriptional signatures enriched for regulatory T cells, B cells, macrophages, and dendritic cells compared to corresponding counterparts in blood. Helper T, cytotoxic T, regulatory T, and T follicular helper cells express multiple immune checkpoints or costimulatory molecules. Cell-cell interaction analysis identifies regulatory B cells with more interactions with CD4+ T cells compared to CD8+ T cells. Macrophages are transcriptionally heterogeneous and conform to M2 polarization characteristics. In addition, immune cells in MPE show the general up-regulation of glycolytic pathways associated with the hypoxic microenvironment. These findings show a detailed atlas of immune cells in human MPE and enhance the understanding of potential diagnostic and therapeutic targets in advanced non-small cell lung cancer.