Pregnancy involves significant immunological changes to support fetal development while protecting the mother from infections. A growing body of evidence supports the importance of immune checkpoint pathways, especially at the maternal-fetal interface, although limited information is available about the peripheral expression of these molecules by CD8+ and CD8- NK cell subsets during the trimesters of pregnancy. Understanding the dynamics of these immune cells and their checkpoint pathways is crucial for elucidating their roles in pregnancy maintenance and potential complications. This study aims to investigate the peripheral expression and functional characteristics of CD8+ and CD8- NK cell subsets throughout pregnancy, providing insights into their contributions to maternal and fetal health. A total of 34 healthy women were enrolled from the first, 30 from the second and 40 from the third trimester of pregnancy. At the same time, 35 healthy age-matched non-pregnant women formed the control group. From peripheral blood, mononuclear cells were separated and stored at -80 °C. CD8+ and CD8- NK cell subsets were analyzed from freshly thawed samples, and surface and intracellular staining was performed using flow cytometric analyses. The proportions of CD56+ NK cells in peripheral blood were similar across groups. While CD8- NKdim cells increased significantly in all trimesters compared to non-pregnant controls, CD8+ NKdim cells showed no significant changes. CD8- NKbright cells had higher frequencies throughout pregnancy, whereas CD8+ NKbright cells significantly increased only in the first and second trimesters. The expression levels of immune checkpoint molecules, such as PD-1 and PD-L1, and cytotoxic-activity-related molecules were stable, with notable perforin and granzyme B increases in CD8- NKbright cells throughout pregnancy. Our study shows that peripheral NK cell populations, especially CD8- subsets, are predominant during pregnancy. This shift suggests a crucial role for CD8- NK cells in balancing maternal immune tolerance and surveillance. The stable expression of immune checkpoint molecules indicates that other regulatory mechanisms may be at work. These findings enhance our understanding of peripheral immune dynamics in pregnancy and suggest that targeting CD8- NKbright cell functions could help manage pregnancy-related immune complications. This research elucidates the stable distribution and functional characteristics of peripheral NK cells during pregnancy, with CD8- subsets being more prevalent. The increased activity of CD8- NKbright cells suggests their critical role in maintaining immune surveillance. Our findings provide a basis for future studies to uncover the mechanisms regulating NK cell function in pregnancy, potentially leading to new treatments for immune-related pregnancy complications.

Despite the numerous studies on the clinical aspects of early-onset preeclampsia, our understanding of the immunological consequences of inadequate placenta development remains incomplete. The Th1-predominance characteristic of early-onset preeclampsia significantly impacts maternal immunotolerance, and the role of immune checkpoint molecules in these mechanisms is yet to be fully elucidated. Our study aims to fill these crucial knowledge gaps. A total of 34 pregnant women diagnosed with early-onset preeclampsia and 34 healthy pregnant women were enrolled in this study. A mononuclear cell fragment from the venous blood was separated and frozen. The CD8+ and CD8- NK cell subpopulations were identified and compared to their immune checkpoint molecule expressions using multicolor flow cytometry. The serum CD226 levels were measured by ELISA. Based on our measures, the frequency of the CD8- subpopulation was significantly higher than that of the CD8+ counterpart in both the NKdim and NKbright subsets. Significantly lower CD226 surface expressions were detected in the preeclamptic group compared to healthy women in all the investigated subpopulations. However, while no difference was observed in the level of the soluble CD226 molecule between the two groups, the CD112 and CD155 surface expressions were significantly different. Our study's findings underscore the significant role of the CD8+ and CD8- NK subpopulations in the Th1-dominated immune environment. This deepens our understanding of early-onset preeclampsia and suggests that each subpopulation could contribute to the compensation mechanisms and the restoration of the immunological balance in this condition, a crucial step toward developing effective interventions.

Galectin-3's (Gal-3) effect on the pathogenesis of chronic lymphocytic leukemia (CLL) has not yet been extensively studied. The present study aims to analyze the potential role of Gal-3 as a prognostic biomarker in CLL patients. The Gal-3 expression was evaluated in CLL cells with RT-qPCR and flow cytometry. Due to the unclear clinical significance of soluble Gal-3 in CLL, our goal was also to assess the prognostic value of Gal-3 plasma level. Because cell survival is significantly affected by the interaction between Gal-3 and proteins such as Bcl-2, the results of Gal-3 expression analysis were also compared with the expression of Bcl-2. The results were analyzed for known prognostic factors, clinical data, and endpoints such as time to first treatment and overall survival time. Our research confirmed that Gal-3 is detected in and on CLL cells. However, using Gal-3 as a potential biomarker in CLL is challenging due to the significant heterogeneity in its expression in CLL cells. Moreover, our results revealed that Gal-3 mRNA expression in leukemic B cells is associated with the expression of proliferation markers (Ki-67 and PCNA) as well as anti-apoptotic protein Bcl-2 and can play an important role in supporting CLL cells.

Although many studies have investigated the clinical aspect of early-onset preeclampsia, our knowledge about the immunological consequences of improper placenta development is scarce. The maternal immunotolerance against the fetus is greatly influenced by the Th1 predominance developed by the mother's immune system. Thirty-two early-onset preeclamptic and fifty-one healthy pregnant women with appropriately matched gestational age were involved in our study. Mononuclear cells were separated from peripheral venous blood and the frequency of CD8⁺, CD4⁺, double positive (DP), and double negative (DN) NKT cell subpopulations was determined using multicolor flow cytometry. Following the characterization, the expression levels of different immune checkpoint receptors and ligands were also defined. Soluble CD226 levels were quantified by ELISA. Novel and significant differences were revealed among the ratios of the investigated NKT subsets and in the expression patterns of PD-1, LAG-3, TIGIT and CD226 receptors. Further differences were determined in the expression of CD112, PD-1, LAG-3 and CD226 MFI values between the early-onset preeclamptic and the healthy pregnant groups. Our results suggest that the investigated NKT subpopulations act differently in the altered immune condition characteristic of early-onset preeclampsia and indicate that the different subsets may contribute to the compensation or maintenance of Th1 predominance.