Invariant natural killer T cells and incidence of first-time coronary events: a nested case-control study.

Aims: Invariant natural killer T (iNKT) cells, a T cell subset that is CD1d-restricted and expresses a semi-invariant T cell receptor, have been proposed to contribute to dyslipidaemia-driven cardiovascular disease due to their ability to specifically recognize lipid antigens. Studies in mice have attributed pro-atherogenic properties to iNKT cells, but studies in humans investigating associations of iNKT cells with incident coronary events (CE) are lacking. Methods and results: Here, we used flow cytometry to enumerate circulating iNKT cells (CD3+ CD1d-PBS57-Tetramer+) in a case-control cohort nested within the prospective population-based Malmö Diet and Cancer Study (n = 416) to explore associations with incident first-time CE during a median follow-up of 14 years. We found a significant inverse association between CD4- and CD8- double negative (DN) iNKT cells and incident CE, with an odds ratio of 0.62 [95% confidence interval (CI) 0.38-0.99; P = 0.046] comparing the highest vs. the lowest tertile of DN iNKT cells. The association remained significant after adjustment for cardiovascular risk factors with an odds ratio of 0.57 (95% CI 0.33-0.99; P = 0.046). In contrast, total iNKT cells were not significantly associated with incident CE after adjustment, with an odds ratio of 0.74 (95% CI 0.43-1.27; P = 0.276). Conclusion: Our findings indicate that animal studies suggesting an atherosclerosis-promoting role for iNKT cells may not translate to human cardiovascular disease as our data show an association between high circulating numbers of DN iNKT cells and decreased risk of incident CE.

Plasma levels of CCL21, but not CCL19, independently predict future coronary events in a prospective population-based cohort.

BACKGROUND AND AIMS: The homeostatic chemokines CCL21 and CCL19 have been explored as biomarkers in cardiovascular disease prediction in patients with established cardiovascular disease, but associations between these chemokines and first-time coronary event incidence have not been investigated before. Here, we explored associations between CCL21 or CCL19 and first-time incident coronary events in the general population-based Malmö Diet and Cancer cohort with two decades of follow-up. METHODS: CCL21 and CCL19 levels in plasma were analysed with ELISA and proximity extension assay and associations with disease incidence were explored with conditional logistic regression in a nested case-control cohort (CCL21; n = 676) and with Cox regression in a population-based cohort (CCL19; n = 4636). RESULTS: High CCL21 levels in plasma were associated with incident first-time coronary events independently of traditional risk factors (odds ratio of 2.64 with 95% confidence interval 1.62-4.31, p < 0.001, comparing the highest versus the lowest tertile of CCL21), whereas CCL19 was not. CCL19 was, however, associated with incident heart failure, as well as increased all-cause, cardiovascular and cancer mortality independently of age and sex. CONCLUSIONS: Even though CCL21 and CCL19 both signal through CCR7, these chemokines may not be interchangeable as disease predictors and CCL21 could be used for prediction of future coronary events in individuals without any previous coronary heart disease history.

LAG3 Regulates T Cell Activation and Plaque Infiltration in Atherosclerotic Mice.

Background: The immune checkpoint receptor lymphocyte-activation gene 3 (LAG3) is a new target for immune checkpoint blockade (ICB), but the effects of LAG3 on atherosclerosis are not known. Objectives: The aim of the study was to evaluate the role of LAG3 on plaque inflammation using murine hypercholesterolemic models of atherosclerosis. Methods: To study the role of LAG3 in atherosclerosis, we investigated both bone marrow chimeras lacking LAG3 in hematopoietic cells as well as global Lag3 -/- knockout mice. Effects of anti-LAG3 monoclonal antibody monotherapy and combination therapy with anti-programmed cell death protein 1 (PD-1) were tested in hypercholesterolemic low-density lipoprotein receptor knockout (Ldlr -/- ) mice and evaluated by histology and flow cytometry. Results: LAG3-deficiency or treatment with blocking anti-LAG3 monoclonal antibodies led to increased levels of both interferon gamma-producing T helper 1 cells and effector/memory T cells, balanced by increased levels of regulatory T cells. Plaque size was affected by neither LAG3 deficiency nor LAG3 blockade, although density of T cells in plaques was 2-fold increased by loss of LAG3. Combination therapy of anti-PD-1 and anti-LAG3 had an additive effect on T cell activation and cytokine production and promoted plaque infiltration of T cells. Conclusions: Loss of LAG3 function promoted T cell activation and accumulation in plaques while not affecting plaque burden. Our report supports further clinical studies investigating cardiovascular risk in patients treated with anti-LAG3 ICB.

Plasma Levels of the Interleukin-1-Receptor Antagonist Are Lower in Women with Gestational Diabetes Mellitus and Are Particularly Associated with Postpartum Development of Type 2 Diabetes.

Diabetes mellitus is a group of diseases characterized by chronic hyperglycemia. Women who develops hyperglycemia for the first time during pregnancy receive the diagnosis gestational diabetes mellitus (GDM). Presently, there is no consensus about the diagnostic criteria for GDM. A majority of these women subsequently develop postpartum overt diabetes making it important to identify these patients as early as possible. In this study we investigated if plasma levels of the interleukin-1 receptor antagonist (IL-1Ra), an endogenous inhibitor of IL-1 signaling, can be used as a complementary biomarker for diagnosing GDM and predicting postpartum development of overt diabetes mellitus. Patients participating in this study (n = 227) were diagnosed with their first GDM 2004-2013 at Lund University Hospital, Lund, Sweden. Healthy pregnant volunteers (n = 156) were recruited from women's welfare centers in the same region 2014-2015. Levels of IL-1Ra and C-peptide were analyzed in ethylenediaminetetraacetic acid (EDTA)-plasma or serum using enzyme linked immunosorbent assay (ELISA). GDM patients had significantly lower levels of IL-1Ra than the control group (p = 0.012). In addition, GDM patients that had developed impaired glucose tolerance (IGT) or type 2 diabetes mellitus postpartum had significantly lower levels of IL-1Ra, and significantly higher levels of C-peptide than GDM patients that had not developed diabetes mellitus postpartum (p = 0.023) and (p = 0.0011) respectively. An inverse correlation was found between IL-1Ra and serum C-peptide levels in the control group (rs = -0.31 p = 0.0001). Our results show that IL-1Ra might be included in a future panel of biomarkers, both for diagnosing GDM to complement blood glucose, and also identifying GDM patients that are at risk of developing type 2 diabetes mellitus postpartum. However, the ROC curve analysis provided a sensitivity of 52.2% and specificity of 67.1%, which nonetheless may not be sufficient enough to use IL-1Ra as a sole biomarker.