Search Results (10)

Introduction: Kidney transplantation is the preferred modality of kidney replacement therapy for eligible patients with end-stage kidney disease (ESKD), given that it has been found to reduce mortality rates, improve quality of life, and is cost-effective compared to dialysis. Recent advancements in human leukocyte antigen (HLA) typing and donor-specific antibody (DSA) detection have helped to reduce the risk of rejection, but antibody-mediated rejection (AMR) can still occur without DSA. Previous studies suggest that rejection can be attributed to antibodies against Non-Human Leucocyte Antigens (non-HLAs). We aimed to acquire further understanding of the prevalence and distribution of non-HLA antibodies in our local population and attempt to correlate these findings with graft outcomes, as well as assess whether non-HLA antibodies can be utilized to determine graft impairment and dysfunction. Methods: We conducted a retrospective study involving kidney transplant recipients between January 2010 and December 2020. All included individuals were aged over 18 and underwent kidney-alone transplants; were ABO- and HLA-compatible; and were matched at A, B, and DR loci (mismatch 0:0:0). HLA testing was negative at the time of transplantation. The samples from both cases of early graft rejection and the control group were tested for non-HLA antibodies using One Lambda LABScreen^TM, Autoantibody kit groups 1, 2, and 3, as well as the Immucor LIFECODES non-HLA autoantibody assay. Results: A total of 850 kidney transplant recipients were included, in which 12 patients experienced early graft rejection within the first month post transplant and 18 patients who did not experience graft rejection were selected as study controls. Our study reported no correlation between the total burden of non-HLA antibodies and early rejection, most likely as the result of a small sample size. Nevertheless, a sub-analysis revealed that specific high-frequency pre-transplant non-HLA antibodies such as GSTT, CXCL11, CXCL10, and HNR, detected by LIFECODES, were associated with rejection (Fisher’s exact test with Bonferroni correction, p < 0.001). Most pre-transplant non-HLA antibody levels were reduced after transplantation, which was attributed to immunosuppression. Conclusion: The ‘high frequency’ non-HLA antibodies displayed an association with graft rejection, though the overall associations between the burden of non-HLA antibodies and rejection episodes remain inconclusive. Further work is needed to establish the rebound phenomenon of non-HLA antibodies, the development of de novo non-HLA antibodies in the long run, and their implications on graft survival. Full article

Diabetes mellitus (DM) is a disease easily complicated by tuberculosis (TB) due to impaired function of the innate immune response. The successes of the discovery of immunomodulatory compounds needs to be continued to introduce new insights into the innate immune response. In previous studies, plant compounds of Etlingera rubroloba A.D. Poulsen (E.rubroloba) were demonstrated to have potential as an immunomodulators. This study aims to isolate and identify the structure of the compounds of E.rubroloba fruit that could effectively improve the function of the innate immune response in individuals with DM infected with TB. The isolation and purification of the compounds of the E.rubroloba extract were carried out by radial chromatography (RC) and thin-layer chromatography (TLC). Identification of the isolated compound structures was determined by measuring the proton (¹H) and carbon (¹³C) nuclear magnetic resonance (NMR). In vitro testing was performed on the immunomodulating activity of the extracts and isolated compounds on DM model macrophages infected with TB antigens. This study succeeded at isolating and identifying the structures of two isolate compounds, namely Sinaphyl alcohol diacetat (BER-1), and Ergosterol peroxide (BER-6). The two isolates were more effective as immunomodulators than the positive controls were, which differed significantly (* p < 0.05) at the reducing interleukin-12 (IL-12) levels and Toll-like receptor-2 (TLR-2) protein expression and increasing the human leucocyte antigen-DR (HLA-DR) protein expression in DM infected with TB. The isolated compound was discovered in E. rubroloba fruits, which has been reported to have the potential to be developed as an immunomodulatory agent. Follow-up testing to determine the mechanism and effectiveness of these compounds as immunomodulators for DM patients is required so that they are not susceptible to TB infection. Full article

Acute pancreatitis is a common gastrointestinal disease with increasing incidence worldwide. COVID-19 is a potentially life-threatening contagious disease spread throughout the world, caused by severe acute respiratory syndrome coronavirus 2. More severe forms of both diseases exhibit commonalities with dysregulated immune responses resulting in amplified inflammation and susceptibility to infection. Human leucocyte antigen (HLA)-DR, expressed on antigen-presenting cells, acts as an indicator of immune function. Research advances have highlighted the predictive values of monocytic HLA-DR (mHLA-DR) expression for disease severity and infectious complications in both acute pancreatitis and COVID-19 patients. While the regulatory mechanism of altered mHLA-DR expression remains unclear, HLA-DR^−/low monocytic myeloid-derived suppressor cells are potent drivers of immunosuppression and poor outcomes in these diseases. Future studies with mHLA-DR-guided enrollment or targeted immunotherapy are warranted in more severe cases of patients with acute pancreatitis and COVID-19. Full article

The aim of this study was to find out whether protease inhibitor 9 (PI-9) and granzyme B (GrB) molecules that contribute to immune response and the immunological privilege of various tissues are expressed in healthy and pathological human corneas. Using cryosections, cell imprints of control corneoscleral discs, we showed that PI-9 was expressed particularly in the endothelium, the superficial and suprabasal epithelium of healthy corneas, limbus, and conjunctiva. GrB was localized in healthy corneal and conjunctival epithelium, while the endothelium showed weak immunostaining. The expression of PI-6 and GrB was confirmed by qRT-PCR. Increased expression levels of the PI-9 and GrB genes were determined when the corneas were cultured with proinflammatory cytokines. Fluorescent and enzymatic immunohistochemistry of pathological corneal explants (corneal melting and herpes virus keratitis) showed pronounced PI-9, GrB, human leucocyte antigen (HLA)-DR, and leukocyte-common antigen (CD45) signals localized in multicellular stromal infiltrates and inflammatory cells scattered in the corneal stroma. We conclude that increased expression of the PI-9 and GrB proteins under pathological conditions and their upregulation in an inflammatory environment indicate their participation in immune response of the cornea during the inflammatory process. Full article

Histones are widely recognized as pro-inflammatory mediators upon their release from the nucleus into the extracellular space. However, their impact on endothelial cell immunogenicity is unknown. Endothelial cells, Human Microvascular Endothelial cells 1 (HMEC1), have been exposed to recombinant histones in order to study their effect on the endothelial phenotype. We then studied the differentiation of CD4⁺-T lymphocytes subpopulations after three days of interaction with endothelial cells in vitro and observed that histone-treated endothelial cells differentiate a suppressive FoxP3⁺ T regulator subpopulation that expressed Human Leucocyte Antigen DR (HLA-DR) and Cytotoxic T-Lymphocyte-Associated protein 4 (CTLA4). Toll-Like Receptor 4 (TLR4) inhibition significantly decreased the expansion of these Treg cells. Moreover, blockade of Interleukin (IL)-6 and Intercellular Adhesion Molecule (ICAM)-1 in cocultures significantly decreased the expansion of Tregs, suggesting an IL-6 and ICAM-1 dependent pathway. Thus, beyond their inflammatory effects, extracellular histones may induce an increase of immunosuppressive Treg population via their action on endothelial cells. Further studies are needed to evaluate the impact on immunosuppression of an increase of peripheral suppressive Treg via endothelial cell activation by histones in vivo. Full article

Biomarkers of disease severity might help with individualizing the management of patients with acute respiratory distress syndrome (ARDS). During sepsis, a sustained decreased expression of the antigen-presenting molecule human leucocyte antigen-DR (HLA-DR) on circulating monocytes is used as a surrogate marker of immune failure. This study aimed at assessing whether HLA-DR expression on alveolar monocytes in the setting of a severe lung infection is associated with their functional alterations. BAL fluid and blood from immunocompetent patients with pneumonia-related ARDS admitted between 2016 and 2018 were isolated in a prospective monocentric study. Alveolar and blood monocytes were immunophenotyped using flow cytometry. Functional tests were performed on alveolar and blood monocytes after in vitro lipopolysaccharide (LPS) stimulation. Phagocytosis activity and intracellular tumor necrosis factor (TNF) production were quantified using fluorochrome-conjugated-specific antibodies. Ten ARDS and seven non-ARDS control patients were included. Patients with pneumonia-related ARDS exhibited significantly lower HLA-DR expression both on circulating (p < 0.0001) and alveolar (p = 0.0002) monocytes. There was no statistically significant difference observed between patient groups (ARDS vs. non-ARDS) regarding both alveolar and blood monocytes phagocytosis activity. After LPS stimulation, alveolar (p = 0.027) and blood (p = 0.005) monocytes from pneumonia-related ARDS patients had a significantly lower intracellular TNF expression than non-ARDS patients. Monocytes from pneumonia-related ARDS patients have a deactivated status and an impaired TNF production capacity but display potent phagocytic activity. HLA-DR level expression should not be used as a surrogate marker of the phagocytic activity or the TNF production capacity of alveolar monocytes. Full article

Multiple Sclerosis (MS) is a serious autoimmune disease. The patient in an advanced state of the disease has restrained mobility and remains handicapped. It is therefore understandable that there is a great need for novel drugs and vaccines for the treatment of MS. Herein we summarise two major approaches applied for the treatment of the disease using peptide molecules alone or conjugated with mannan. The first approach focuses on selective myelin epitope peptide or peptide mimetic therapy alone or conjugated with mannan, and the second on immune-therapy by preventing or controlling disease through the release of appropriate cytokines. In both approaches the use of cyclic peptides offers the advantage of increased stability from proteolytic enzymes. In these approaches, the synthesis of myelin epitope peptides conjugated to mannan is of particular interest as this was found to protect mice against experimental autoimmune encephalomyelitis, an animal model of MS, in prophylactic and therapeutic protocols. Protection was peptide-specific and associated with reduced antigen-specific T cell proliferation. The aim of the studies of these peptide epitope analogs is to understand their molecular basis of interactions with human autoimmune T-cell receptor and a MS-associated human leucocyte antigen (HLA)-DR2b. This knowledge will lead the rational design to new beneficial non-peptide mimetic analogs for the treatment of MS. Some issues of the use of nanotechnology will also be addressed as a future trend to tackle the disease. We highlight novel immunomodulation and vaccine-based research against MS based on myelin epitope peptides and strategies developed in our laboratories. Full article

Our understanding of the interplay between human adipose tissue and the immune system is limited. The mesothelium, an immunologically active structure, emerged as a source of visceral adipose tissue. After investigating the mesothelial properties of human visceral and subcutaneous adipose tissue and their progenitors, we explored whether the dysfunctional obese and Crohn’s disease environments influence the mesothelial/mesenchymal properties of their adipocyte precursors, as well as their ability to mount an immune response. Using a tandem transcriptomic/proteomic approach, we evaluated the mesothelial and mesenchymal expression profiles in adipose tissue, both in subjects covering a wide range of body-mass indexes and in Crohn’s disease patients. We also isolated adipose tissue precursors (adipose-derived stem cells, ASCs) to assess their mesothelial/mesenchymal properties, as well as their antigen-presenting features. Human visceral tissue presented a mesothelial phenotype not detected in the subcutaneous fat. Only ASCs from mesenteric adipose tissue, named creeping fat, had a significantly higher expression of the hallmark mesothelial genes mesothelin (MSLN) and Wilms’ tumor suppressor gene 1 (WT1), supporting a mesothelial nature of these cells. Both lean and Crohn’s disease visceral ASCs expressed equivalent surface percentages of the antigen-presenting molecules human leucocyte antigen—DR isotype (HLA-DR) and CD86. However, lean-derived ASCs were predominantly HLA-DR ^dim, whereas in Crohn’s disease, the HLA-DR ^bright subpopulation was increased 3.2-fold. Importantly, the mesothelial-enriched Crohn’s disease precursors activated CD4⁺ T-lymphocytes. Our study evidences a mesothelial signature in the creeping fat of Crohn’s disease patients and its progenitor cells, the latter being able to present antigens and orchestrate an immune response. Full article

Background: Human Leucocyte Antigens (HLA) represent the genetic loci most strongly linked to Multiple Sclerosis (MS). Apart from HLA-DR and HLA–DQ, HLA-DP alleles have been previously studied regarding their role in MS pathogenesis, but to a much lesser extent. Our objective was to investigate the risk/resistance influence of HLA-DPB1 alleles in Hellenic patients with early- and adult-onset MS (EOMS/AOMS), and possible associations with the HLA-DRB1*15:01 risk allele. Methods: One hundred MS-patients (28 EOMS, 72 AOMS) fulfilling the McDonald-2010 criteria were enrolled. HLA genotyping was performed with standard low-resolution Sequence-Specific Oligonucleotide techniques. Demographics, clinical and laboratory data were statistically processed using well-defined parametric and nonparametric methods and the SPSSv22.0 software. Results: No significant HLA-DPB1 differences were found between EOMS and AOMS patients for 23 distinct HLA-DPB1 and 12 HLA-DRB1 alleles. The HLA-DPB1*03 allele frequency was found to be significantly increased, and the HLA-DPB1*02 allele frequency significantly decreased, in AOMS patients compared to controls. The HLA-DPB1*04 allele was to be found significantly decreased in AOMS and EOMS patients compared to controls. Conclusions: Our study supports the previously reported risk susceptibility role of the HLA-DPB1*03 allele in AOMS among Caucasians. Additionally, we report for the first time a protective role of the HLA-DPB1*04 allele among Hellenic patients with both EOMS and AOMS. Full article

Despite improvement in the prognosis of HIV/AIDS (human immunodeficiency virus/acquired immune deficiency syndrome) patients on antiretroviral therapy (ART), cryptococcal meningitis (CM) still causes 10–15% mortality among HIV-infected patients. The immunological impact of ART on the CD4⁺ and CD8⁺ T cell repertoire during cryptococcal co-infection is unclear. We determined longitudinal phenotypic changes in T cell subsets among patients with CM after they initiated ART. We hypothesized that ART alters the clonotypic phenotype and structural composition of CD4⁺ and CD8⁺ T cells during CM co-infection. For this substudy, peripheral blood mononuclear cells (PBMC) were isolated at four time points from CM patients following ART initiation during the parent study (ClinicalTrials.gov number, NCT01075152). Phenotypic characterization of CD4⁺ and CD8⁺ T cells was done using T cell surface marker monoclonal antibodies by flow cytometry. There was variation in the expression of immunophenotypic markers defining central memory (CD27⁺CD45R0⁺), effector memory (CD45R0⁺CD27^–), immune activation (CD38⁺ and Human Leucocyte Antigen DR (HLA-DR⁺), and exhaustion (Programmed cell death protein one (PD-1) in the CD4⁺ T cell subset. In comparison to the CD4⁺ T cell population, the CD8⁺ central memory subset declined gradually with minimal increase in the effector memory subset. Both CD4⁺ and CD8⁺ T cell immune exhaustion and activation markers remained elevated over 12 weeks. The relative surge and decline in the expression of T cell surface markers outlines a variation in the differentiation of CD4⁺ T cells during ART treatment during CM co-infection. Full article