Decoding immune-related gene-signatures in colorectal neoplasia.

Background: Colorectal cancer (CRC) is a significant health issue, with notable incidence rates in Norway. The immune response plays a dual role in CRC, offering both protective effects and promoting tumor growth. This research aims to provide a detailed screening of immune-related genes and identify specific genes in CRC and adenomatous polyps within the Norwegian population, potentially serving as detection biomarkers. Methods: The study involved 69 patients (228 biopsies) undergoing colonoscopy, divided into CRC, adenomatous polyps, and control groups. We examined the expression of 579 immune genes through nCounter analysis emphasizing differential expression in tumor versus adjacent non-tumorous tissue and performed quantitative reverse transcription polymerase chain reaction (RT-qPCR) across patient categories. Results: Key findings include the elevated expression of CXCL1, CXCL2, IL1B, IL6, CXCL8 (IL8), PTGS2, and SPP1 in CRC tissues. Additionally, CXCL1, CXCL2, IL6, CXCL8, and PTGS2 showed significant expression changes in adenomatous polyps, suggesting their early involvement in carcinogenesis. Conclusions: This study uncovers a distinctive immunological signature in colorectal neoplasia among Norwegians, highlighting CXCL1, CXCL2, IL1B, IL6, CXCL8, PTGS2, and SPP1 as potential CRC biomarkers. These findings warrant further research to confirm their role and explore their utility in non-invasive screening strategies.

Variation in Platelet Activation State in Pre-Donation Whole Blood: Effect of Time of Day and ABO Blood Group.

Background: Whilst there has been investigation into the effect of time of the day on platelet activation and function in healthy individuals, there is a lack of studies in the literature to examine this relationship among platelet donors. Methods: We assessed the extent of platelet activation by percentage of platelets with surface-expressed P-selectin and flow cytometry in samples of whole blood from a group of qualified platelet donors (n = 84). Results: The mean (SD) percentage of activated platelets in the pre-donation blood samples was 1.85 ± 1.57% (range 0.2-7.5%). In univariate analyses, the percentage of activated platelets was significantly and inversely correlated with the collection time (ie, the time of day blood samples were collected) (r = -0.35, p = 0.001) and positively correlated to mean platelet volume (MPV) (r = 0.29, p = 0.008). A weaker positive correlation was also observed with ABO blood group (r = 0.228, p = 0.036). Analysis of the collection time as a categorical variable showed a greater degree of activated platelets in samples collected between 8:00 h and 10:00 h than in samples collected during the hours of >10:00 h ≤14:00 h (2.5 ± 1.8 versus 1.1 ± 0.74, p < 0.001). In the adjusted linear regression model, collection time was a significant independent predictor of platelet activation state in whole blood (ß = -0.26; p < 0.001), as did ABO blood group (ß = 0.55; p = 0.019). Conclusion: Our results show that collection time is the most important predictor of platelet activation state in pre-donation whole blood among platelet donors. This work may have implications for optimizing the timing of platelet donation.

Human macrophage C-type lectin forms a heteromeric receptor complex with Mincle but not Dectin-2.

MCL, Mincle and Dectin-2 are C-type lectin receptors expressed by subsets of myeloid cells, and their genes cluster together in the APLEC/Dectin-2 gene complex. We have previously shown that MCL and Mincle form a heterodimer in the rat, and others have shown that MCL and Dectin-2 form a heterodimer in the mouse. In the rat, Dectin-2 is a pseudogene, but here, we examine the association of the three receptors in human. In co-transfection experiments analyzed with flow cytometry and immunoprecipitation, we here show that human MCL and Mincle form a disulphide-linked heterodimer that associates with the signalling adaptor molecule FcεRIγ, in accordance with our previous findings in the rat. In contrast to previous findings in the rat, data in this paper indicate a direct association of MCL with FcεRIγ, as previously shown for mouse MCL. We were unable to demonstrate the formation of a heterodimer between human MCL and Dectin-2. Thus, despite similarities, there may be important differences in the conformation of these receptors between rat, mouse and human, and this may have functional consequences.

Health Behavior and Lifestyle Trends among Platelet Donors: Results from a Questionnaire-Based Survey in Norway.

BACKGROUND: Blood donors are on average healthier than the general population, a phenomenon known as the "healthy donor effect." Earlier studies have also pointed to healthier behaviors among whole blood donors than the general population. This study is aimed at assessing the prevalence of four healthy behaviors (sufficient physical activity, avoiding cigarette smoking, low to moderate alcohol use, and maintaining a healthy weight) among platelet donors and to compare the results with those in the general population of similar ages. METHODS: Eighty-six platelet donors were asked to complete a questionnaire designed to assess physical activity, smoking, and alcohol use. Sociodemographic information including gender, age, and education was also collected from all participants. Chi-square statistics and logistic regression were used in statistical analysis. RESULTS: The mean age of the study donors was 51 years, 56% were female. Most were employed (90%), and 48% hold a bachelor's or higher degree. The prevalence of healthy behaviors differed by education gradients but not by gender and age. About 49% of the donors met the weekly physical activity recommendations, less than 5% were daily smokers, and~26% were classified as more frequent drinkers (≥1 to ≤5 times per week). The corresponding percentages for the general population were, respectively, 33%, 13%, and 35%. The prevalence of overweight and obesity, as assessed by body mass index (BMI), among donors were 50% and 29%, respectively, much higher than the current prevalence of overweight and obesity of 37% and 19%, respectively, among adults in the general population. CONCLUSIONS: The individual health behaviors of the majority of the study population could be characterized by a relatively high level of physical activity, low prevalence of daily smoking, and moderate alcohol drinking. The above-average overweight/obesity prevalence among platelet donors in this cohort is of concern because of the potential serious health consequences and it warrants further reflection.

Evaluation of the detection of blasts by Sysmex hematology instruments, CellaVision DM96, and manual microscopy using flow cytometry as the confirmatory method.

INTRODUCTION: The aim of the present study was to evaluate the diagnostic ability of blast flags generated by Sysmex instruments (XE/XN) by comparing with immunophenotyping by flow cytometry (IFCM). Additionally, the ability of manual microscopy and CellaVision DM96 (pre- and reclassification) to predict the presence of "true" blasts was investigated. METHODS: Blood samples (n = 240) with suspect pathology flags reported by the XE were collected from the daily workload and examined by the XN, by manual microscopy, by CellaVision DM96 and by IFCM (CytoDiff Panel). RESULTS: The ROC analysis for blasts showed an area under the curve of 0.64 ("Blasts?") (XE), 0.57 ("Blasts/Abn Lympho?") (XN), 0.75 (CellaVision preclassification procedure), 0.78 (CellaVision reclassification procedure), and 0.81 (manual microscopy). The sensitivity of blast detection varied between the methods from 0.41 (XE) to 0.90 (XN), and the specificity varied from 0.17 (XN) to 0.95 (CellaVision reclassification). CONCLUSIONS: The CellaVision reclassification procedure has a diagnostic ability for predicting blasts close to that of manual microscopy. The blood smear methods show a notable number of false negative results. The Sysmex XN reported a higher rate of true positive blast flags than the XE. Taken together, the CytoDiff method could be a useful alternative to smear examination to correctly identify blasts.

Natural Killer Cell Reduction and Uteroplacental Vasculopathy.

Uterine natural killer cells are important for uteroplacental development and pregnancy maintenance. Their role in pregnancy disorders, such as preeclampsia, is unknown. We reduced the number of natural killer cells by administering rabbit anti-asialo GM1 antiserum in an established rat preeclamptic model (female human angiotensinogen×male human renin) and evaluated the effects at the end of pregnancy (day 21), compared with preeclamptic control rats receiving normal rabbit serum. In 100% of the antiserum-treated, preeclamptic rats (7/7), we observed highly degenerated vessel cross sections in the mesometrial triangle at the end of pregnancy. This maternal uterine vasculopathy was characterized by a total absence of nucleated/living cells in the vessel wall and perivascularly and prominent presence of fibrosis. Furthermore, there were no endovascular trophoblast cells within the vessel lumen. In the control, normal rabbit serum-treated, preeclamptic rats, only 20% (1/5) of the animals displayed such vasculopathy. We confirmed the results in healthy pregnant wild-type rats: after anti-asialo GM1 treatment, 67% of maternal rats displayed vasculopathy at the end of pregnancy compared with 0% in rabbit serum-treated control rats. This vasculopathy was associated with a significantly lower fetal weight in wild-type rats and deterioration of fetal brain/liver weight ratio in preeclamptic rats. Anti-asialo GM1 application had no influence on maternal hypertension and albuminuria during pregnancy. Our results show a new role of natural killer cells during hypertensive pregnancy in maintaining vascular integrity. In normotensive pregnancy, this integrity seems important for fetal growth.

Mincle, the receptor for mycobacterial cord factor, forms a functional receptor complex with MCL and FcεRI-γ.

Upon receptor activation, the myeloid C-type lectin receptor Mincle signals via the Syk-CARD9-Bcl10-MALT1 pathway. It does so by recruiting the ITAM-bearing FcεRI-γ. The related receptor macrophage C-type Lectin (MCL) has also been shown to be associated with Syk and to be dependent upon this signaling axis. We have previously shown that MCL co-precipitates with FcεRI-γ, but were unable to show a direct association, suggesting that MCL associates with FcεRI-γ via another molecule. Here, we have used rat primary cells and cell lines to investigate this missing link. A combination of flow cytometric and biochemical analysis showed that Mincle and MCL form heteromers on the cell surface. Furthermore, association with MCL and FcεRI-γ increased Mincle expression and enhanced phagocytosis of Ab-coated beads. The results presented in this paper suggest that the Mincle/MCL/FcεRI-γ complex is the functionally optimal form for these C-type lectin receptors on the surface of myeloid cells.

Rat macrophage C-type lectin is an activating receptor expressed by phagocytic cells.

Macrophage C-type lectin (MCL) is a membrane surface receptor encoded by the Antigen Presenting Lectin-like gene Complex (APLEC). We generated a mouse monoclonal antibody for the study of this receptor in the rat. We demonstrate that rat MCL is expressed on blood monocytes and neutrophils, as well as on several tissue macrophage populations, including alveolar and peritoneal cavity macrophages. We also demonstrate MCL expression on a subset of resident spleen macrophages. Immunohistochemistry analysis of the spleen showed staining specifically in the marginal zone and red pulp. Exposure to pro-inflammatory mediators or to yeast cell wall extract (zymosan) increased surface MCL expression on peritoneal macrophages. We characterized a rat myeloid cell line, RMW, which expresses high levels of MCL. We found that MCL co-immunoprecipitated with the activating adaptor protein FcεRIγ in these cells. Moreover, beads coated with anti-MCL antibody increased phagocytosis in the RMW cells. Together, these observations indicate that rat MCL is a receptor that activates phagocytosis in myeloid cells under inflammatory conditions.

Paired opposing leukocyte receptors recognizing rapidly evolving ligands are subject to homogenization of their ligand binding domains.

Some leukocyte receptors come in groups of two or more where the partners share ligand(s) but transmit opposite signals. Some of the ligands, such as MHC class I, are fast evolving, raising the problem of how paired opposing receptors manage to change in step with respect to ligand binding properties and at the same time conserve opposite signaling functions. An example is the KLRC (NKG2) family, where opposing variants have been conserved in both rodents and primates. Phylogenetic analyses of the KLRC receptors within and between the two orders show that the opposing partners have been subject to post-speciation gene homogenization restricted mainly to the parts of the genes that encode the ligand binding domains. Concerted evolution similarly restricted is demonstrated also for the KLRI, KLRB (NKR-P1), KLRA (Ly49), and PIR receptor families. We propose the term merohomogenization for this phenomenon and discuss its significance for the evolution of immune receptors.