Search

Summary: Natural killer (NK) cells play a crucial role in controlling viral infections. The ability to kill infected cells without prior immunization, yet being tolerant to self, healthy cells, depends on the balance of germ-line encoded surface receptors. NK-cell receptors are divided into either activating, leading to activation of NK cell and its cytotoxic and pro-inflammatory activity, or inhibitory, providing tolerance for a target cell. The signals from inhibitory receptors dominate and NK-cell activation requires stimulation of activating receptors. In viral infections, NK-cell interaction with infected cells can result in activation, memory-like NK-cell differentiation, or NK-cell exhaustion, which constitutes one of the viral immune evasion mechanisms. All of these states are associated with the modulation of NK-cell receptor expression. In this review, we summarize the current knowledge of NK-cell receptors and their role in viral infection control, as well as the alterations of their expression observed in acute or chronic infections. We present recently discovered SARS-CoV-2-mediated modulation of NK-cell receptor expression and compare them with other human viral infections. Finally, since modulation of NK-cell receptor activation gives a promising addition to currently used antiviral therapies, we briefly discuss the clinical significance and future perspective of the application of agonists or antagonists of activating and inhibitory receptors, respectively. In sum, our review shows that although much is known about NK-cell receptor biology, a deeper understanding of NK-cell receptors role in viral infections is still needed. This review summarizes recent knowledge on NK cell receptor alterations mediated by viral infections, along with the mechanisms responsible for this modulation. We present recently discovered SARS-CoV-2-mediated modulation of NK cell receptor expression and compare them with other human viral infections. Graphical Abstract [ABSTRACT FROM AUTHOR]

Simple Summary: Globally, colorectal cancer is the third and second most common cancer in men and women, respectively. Due to its late diagnosis, morbidity and mortality are on the rise, which legitimizes the search for new markers for early and precise detection of cancer development. The knowledge about the short, non-coding RNA molecule (microRNA) expression profile in tumor cancer cell lines and extracellular vesicles derived from them may help to establish microRNA as useful markers for monitoring tumor signatures in body fluids (i.e., blood). Here, we present a comprehensive analysis of microRNA profiles of four colorectal cancer cell lines, one normal colon epithelium cell line and extracellular vesicles derived from them. Data are supplemented with preliminary results acquired from a group of colorectal cancer patients. Globally, an increasing prevalence of colorectal cancer (CRC) prompts a need for the development of new methods for early tumor detection. MicroRNAs (also referred to as miRNAs) are short non-coding RNA molecules that play a pivotal role in the regulation of gene expression. MiRNAs are effectively transferred to extracellular vesicle (EVs) membrane sacs commonly released by cells. Our study aimed to examine the expression of miRNAs in four CRC cell lines and EVs derived from them (tumor EVs) in comparison to the normal colon epithelium cell line and its EVs. EVs were isolated by ultracentrifugation from the culture supernatant of SW480, SW620, SW1116, HCT116 and normal CCD841CoN cell lines and characterized according to the MISEV2023 guidelines. MiRNAs were analyzed by small RNA sequencing and validated by quantitative PCR. The performed analysis revealed 22 common miRNAs highly expressed in CRC cell lines and effectively transferred to tumor EVs, including miR-9-5p, miR-182-5p, miR-196b-5p, miR-200b-5p, miR-200c-3p, miR-425-5p and miR-429, which are associated with development, proliferation, invasion and migration of colorectal cancer cells, as well as in vesicle maturation and transport-associated pathways. In parallel, normal cells expressed miRNAs, such as miR-369 and miR-143, which play a role in proinflammatory response and tumor suppression. The analysis of selected miRNAs in plasma-derived EVs and tumor samples from CRC patients showed the similarity of miRNA expression profile between the patients' samples and CRC cell lines. Moreover, miR-182-5p, miR-196-5p, miR-425-5p and miR-429 were detected in several EV samples isolated from patients' plasma. Our results suggest that miR-182-5p, miR-196b-5p and miR-429 are differentially expressed between EVs from CRC patients and healthy donors, which might have clinical implications. [ABSTRACT FROM AUTHOR]

Studying viral infections necessitates well-designed cell culture models to deepen our understanding of diseases and develop effective treatments. In this study, we present a readily available ex vivo 3D co-culture model replicating the human intestinal mucosa. The model combines fully differentiated human intestinal epithelium (HIE) with human monocyte-derived macrophages (hMDMs) and faithfully mirrors the in vivo structural and organizational properties of intestinal mucosal tissues. Specifically, it mimics the lamina propria, basement membrane, and the air-exposed epithelial layer, enabling the pioneering observation of macrophage migration through the tissue to the site of viral infection. In this study, we applied the HIE-hMDMs model for the first time in viral infection studies, infecting the model with two globally significant viruses: severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and human norovirus GII.4. The results demonstrate the model's capability to support the replication of both viruses and show the antiviral role of macrophages, determined by their migration to the infection site and subsequent direct contact with infected epithelial cells. In addition, we evaluated the production of cytokines and chemokines in the intestinal niche, observing an increased interleukin-8 production during infection. A parallel comparison using a classical in vitro cell line model comprising Caco-2 and THP-1 cells for SARS-CoV-2 experiments confirmed the utility of the HIE-hMDMs model in viral infection studies. Our data show that the ex vivo tissue models hold important implications for advances in virology research. [ABSTRACT FROM AUTHOR]

Background and objectives: T regulatory lymphocytes (Treg) are one of the subsets of T-lymphocytes involved in the interaction of neoplastic tumors and the host immune system, and they may impair the immune reaction against cancer. It has been shown that Treg are increased in the peripheral blood of patients with various cancers. In colorectal cancer, the prognostic role of Treg remains controversial. Colorectal cancer is a heterogenous disease, with many variations stemming from its primary tumor location. The aim of this study is to analyse the relationship between the amount of Treg in the peripheral blood of patients with left-sided colorectal cancer in various stages of disease and long-term survival. Materials and Methods: A prospective analysis of 94 patients with left-sided colorectal cancer and a group of 21 healthy volunteers was carried out. Treg levels in peripheral blood were analysed using flow cytometry. Results: There was a statistically significant difference between the amount of Treg in the Ist and IInd TNM stages ( p = 0.047). The number of Treg in the entire study group was significantly lower than in the control group ( p = 0.008) and between patients in stages II and III and the control group ( p = 0.003 and p = 0.018). The group of pT3+pT4 patients also had significantly lower Treg counts in their peripheral blood than the control group ( p = 0.005). In the entire study group, the level of Treg cells in the peripheral blood had no influence on survival. The analysis of the TNM stage subgroups also showed no difference in survival between patients with "low" and "high" Treg counts. Conclusion : The absolute number of Treg in the peripheral blood of patients with left-sided colorectal cancer was significantly decreased in comparison to healthy controls, especially for patients with stage II+III disease. Treg presence in the peripheral blood had no impact on survival.

Introduction: In this study we describe a patient with gross deletion containing the BTK and TIMM8A genes. Mutations in these genes are responsible for X-linked agammaglobulinemia and Mohr-Tranebjaerg syndrome, respectively. X linked agammaglobulinemia is a rare primary immunodeficiency characterized by low levels of B lymphocytes and recurrent microbial infections, whereas, Mohr-Tranebjaerg syndrome is a progressive neurodegenerative disorder with early onset of sensorineural deafness., Material and Methods: For neuroimaging, the magnetic resonance imaging and magnetic resonance spectroscopy of the brain were performed. Microarray analysis was performed to establish the extent of deletion., Results: The first clinical symptoms observed in our patient at the age of 6 months were connected with primary humoral immunodeficiency, whereas clinical signs of MTS emerged in the third year of live. Interestingly, the loss of speech ability was not accompanied by hearing failure. Neuroimaging of the brain suggested leukodystrophy. Molecular tests revealed contiguous X-chromosome deletion syndrome encompassing BTK (from exons 6 through 19) and TIMM8A genes. The loss of the patient's DNA fragment was accurately localized from 100 601 727 to 100 617 576 bp on chromosome's loci Xq22.1., Conclusions: We diagnosed XLA-MTS in the first Polish patient on the basis of particular molecular methods. We detected neurodegenerative changes in MRI and MR spectroscopy in this patient. Our results provide further insight into this rare syndrome., Competing Interests: The authors declare no conflict of interest.

INTRODUCTION    A different clinical course and pattern of skeletal involvement in peripheral and axial spondyloarthritis (SpA) suggests a distinct pathophysiology of these 2 phenotypic manifestations of SpA. Monocytes, as part of the innate immune system, seem to play an important role in the pathogenesis of SpA, but the exact inflammatory pathways remain to be elucidated. Regulatory T lymphocytes (Treg) and Th17 lymphocytes are also known to influence proinflammatory and anti‑inflammatory reactions. OBJECTIVES    The aim of our study was to compare the absolute numbers of monocyte subpopulations, Treg, and Th17 lymphocytes with clinical measures of disease activity in patients with peripheral and axial SpA. PATIENTS AND METHODS    We enrolled 21 patients with peripheral SpA and 27 patients with axial SpA diagnosed according to the Assessment of SpondyloArthritis International Society classification criteria, as well as 23 healthy controls. Patients were under 45 years, naïve to synthetic and biological disease‑modifying antirheumatic drugs and without the administration of systemic glucocorticoids. The absolute numbers of classical, intermediate, nonclassical monocytes, Treg, and Th17 in peripheral blood were analyzed. Disease activity was assessed using the Ankylosing Spondylitis Disease Activity Score (ASDAS-CRP), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and Disease Activity Score 28 (DAS28). RESULTS    In patients with SpA, the number of circulating nonclassical monocytes was decreased in comparison with controls. Only in the peripheral SpA group, a significant negative correlation was found between the concentration of nonclassical monocytes and DAS28 and the number of swollen joints. The 3 groups did not differ in terms of the concentrations of classical or intermediate monocytes and Treg or Th17 lymphocytes. CONCLUSIONS    Nonclassical monocytes may play a role in induction and perpetuation of peripheral joint inflammation, at least in peripheral SpA, as cells infiltrating the synovium.

The loss of the CD16a, Fc receptor for IgG type III, (FcgammaRIIIa) B73.1/Leu11c binding epitope, detected by the monoclonal antibody (mAb) used in routine enumeration of NK cells or monocytes, has been observed in children with recurrent viral infections. It has also been linked with the change of leucine (L) to histidine (H) or arginine (R) at amino acid position 48 (FcgammaRIIIa-48L/R/H) in the CD16a receptor. The reactivity of the anti-CD16a clone B73.1/Leu11c mAb with monocytes and NK cells was examined in patients with primary immunodeficiencies (n=167), gastrointestinal malignancies (n=91) and healthy subjects (n=88). Cells of only 12 children, 11 with diagnosed primary immunodeficiency and one with recurrent bacterial infections were not reactive with B73.1/Leu11c mAb. In contrast to previous findings, no linkage between the loss of B73.1/Leu11c binding epitope and herpes virus infections was observed. Furthermore, the sequence analysis of the FcgammaRIIIa gene performed in these 12 patients and 11 healthy subjects revealed that all of them had FcgammaRIIIa-48L/L genotype. Thus, the loss of B73.1/Leu11c binding epitope was not associated with the FcgammaRIIIa-48 polymorphism. The commonly described FcgammaRIIIa-158 polymorphism was determined to be 158V/V in 11 patients and 5 healthy subjects. Moreover, no linkage between FcgammaRIIIa-48L/L and -158F/F genotypes was observed. It is suggested that the loss of the B73.1/Leu11c binding epitope is connected with primary immunodeficiency disorders, but not associated with the FcgammaRIIIa-48 polymorphism.