Association Between Programed Cell Death-1 and CD4+ T Cell Alterations in Different Phases of Ischemic Stroke Patients

Circulating T-cell subsets discrepancy between bipolar disorder and major depressive disorder during mood episodes: A naturalistic, retrospective study of 1015 cases

AIMS

We aimed to investigate whether peripheral T-cell subsets could be a biomarker to distinguish major depressive disorder (MDD) and bipolar disorder (BD).

METHODS

Medical records of hospitalized patients in the Department of Psychiatry, the First Affiliated Hospital, Zhejiang University School of Medicine, from January 2015 to September 2020 with a discharge diagnosis of MDD or BD were reviewed. Patients who underwent peripheral blood examination of T-cell subtype proportions, including CD3+, CD4+, CD8+ T-cell, and natural killer (NK) cells, were enrolled. The Chi-square test, t-test, or one-way analysis of variance were used to analyze group differences. Demographic profiles and T-cell data were used to construct a random forest classifier-based diagnostic model.

RESULTS

Totally, 98 cases of BD mania, 459 cases of BD depression (BD-D), and 458 cases of MDD were included. There were significant differences in the proportions of CD3+, CD4+, CD8+ T-cell, and NK cells among the three groups. Compared with MDD, the BD-D group showed higher CD8+ but lower CD4+ T-cell and a significantly lower ratio of CD4+ and CD8+ proportions. The random forest model achieved an area under the curve of 0.77 (95% confidence interval: 0.71-0.83) to distinguish BD-D from MDD patients.

CONCLUSION

These findings imply that BD and MDD patients may harbor different T-cell inflammatory patterns, which could be a potential diagnostic biomarker for mood disorders.

T-cell receptor signaling modulated by the co-receptors: Potential targets for stroke treatment

Stroke is a severe and life-threatening disease, necessitating more research on new treatment strategies. Infiltrated T lymphocytes, an essential adaptive immune cell with extensive effector function, are crucially involved in post-stroke inflammation. Immediately after the initiation of the innate immune response triggered by microglia/macrophages, the adaptive immune response associated with T lymphocytes also participates in the complex pathophysiology of stroke and partially informs the outcome of stroke. Preclinical and clinical studies have revealed the conflicting roles of T cells in post-stroke inflammation and as potential therapeutic targets. Therefore, exploring the mechanisms that underlie the adaptive immune response associated with T lymphocytes in stroke is essential. The T-cell receptor (TCR) and its downstream signaling regulate T lymphocyte differentiation and activation. This review comprehensively summarizes the various molecules that regulate TCR signaling and the T-cell response. It covers both the co-stimulatory and co-inhibitory molecules and their roles in stroke. Because immunoregulatory therapies targeting TCR and its mediators have achieved great success in some proliferative diseases, this article also summarizes the advances in therapeutic strategies related to TCR signaling in lymphocytes after stroke, which can facilitate translation. DATA AVAILABILITY: No data was used for the research described in the article.

Elevation of neutrophil carcinoembryonic antigen-related cell adhesion molecule 1 associated with multiple inflammatory mediators was related to different clinical stages in ischemic stroke patients

BACKGROUND

We aimed to analyze the level of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) in neutrophils of ischemic stroke (IS) patients at different stages, together with its roles in neutrophils.

PATIENTS AND METHODS

Sixty-seven patients were classified into acute phase group (n = 19), subacute phase group (n = 28), and stable phase group (n = 20), and 20 healthy individuals who had received physical examination at the same time period as healthy control. We then analyzed the expression level of CEACAM1 and cell viability in CEACAM1 positive and CEACAM1 negative neutrophils by flow cytometry and the content of plasma CEACAM1, neutrophil gelatinase-associated lipocalin (NGAL), matrix metalloproteinases-9 (MMP-9) was measured using enzyme-linked immunosorbent assay (ELISA), while that of interleukin-10 (IL-10) and tumor necrosis factor (TNF) was determined using a Human Enhanced Sensitivity Flex set.

RESULTS

Compared with healthy control, the percentage of CEACAM1 positive neutrophils in IS patients showed a significant increase, and a significant increase was also noticed in the content of plasma CEACAM1 at the subacute stage. Reduction in cell viability was observed in CEACAM1 positive neutrophils compared with CEACAM1 negative counterparts. There was a positive correlation between CEACAM1 expression rate in neutrophils and plasma CEACAM1 and IL-10 content in the subacute group. Compared with acute group and healthy control group, there was an instinct increase in the level of plasma MMP-9 and NGAL in subacute group.

CONCLUSIONS

Our data showed that there was a rapid increase of CEACAM1 in neutrophils at the acute stage of IS. We speculated that CEACAM1 may serve as an inhibitory regulator involving in the progression of IS.

Application value and challenge of traditional Chinese medicine carried by ZIF-8 in the therapy of ischemic stroke

Stroke is a group of major diseases that cause death or disability in adults, with high incidence and lack of available therapeutic strategies. Although traditional Chinese medicine (TCM) has continuously achieved good effects in the therapy of stroke while there is still not convincing due to the limitation of blood-brain permeability, as well as the individual differences in usage and dosage. With the improvement of nanotechnology, TCM nanopreparation has gradually become a research hotspot in various fields due to its advantages in permeating the blood-brain barrier, targeting delivery, enhancing sustained-release drug delivery, changing the distribution in the body, and improving bioavailability. Zeolitic imidazolate framework-8 (ZIF-8) is an ideal nano-drug delivery system for adsorption, catalysis, and drug loading, which is a biocompatible metal-organic framework framed by 2-methylimidazole and zinc ions. At present, ZIF-8 was wildly used in the treatment of ischemic stroke. However, challenges remain persists for its clinical application, such as preparation technology, detection technology in vivo, targeting specificity, safety and stability, and so forth. Therefore, more efforts need to overcome the above problems to develop the application of TCM nanopreparations in the therapy of ischemia/reperfusion in the future.

The immune response of T cells and therapeutic targets related to regulating the levels of T helper cells after ischaemic stroke

Through considerable effort in research and clinical studies, the immune system has been identified as a participant in the onset and progression of brain injury after ischaemic stroke. Due to the involvement of all types of immune cells, the roles of the immune system in stroke pathology and associated effects are complicated. Past research concentrated on the functions of monocytes and neutrophils in the pathogenesis of ischaemic stroke and tried to demonstrate the mechanisms of tissue injury and protection involving these immune cells. Within the past several years, an increasing number of studies have elucidated the vital functions of T cells in the innate and adaptive immune responses in both the acute and chronic phases of ischaemic stroke. Recently, the phenotypes of T cells with proinflammatory or anti-inflammatory function have been demonstrated in detail. T cells with distinctive phenotypes can also influence cerebral inflammation through various pathways, such as regulating the immune response, interacting with brain-resident immune cells and modulating neurogenesis and angiogenesis during different phases following stroke. In view of the limited treatment options available following stroke other than tissue plasminogen activator therapy, understanding the function of immune responses, especially T cell responses, in the post-stroke recovery period can provide a new therapeutic direction. Here, we discuss the different functions and temporal evolution of T cells with different phenotypes during the acute and chronic phases of ischaemic stroke. We suggest that modulating the balance between the proinflammatory and anti-inflammatory functions of T cells with distinct phenotypes may become a potential therapeutic approach that reduces the mortality and improves the functional outcomes and prognosis of patients suffering from ischaemic stroke.

Adaptive Immunity Regulation and Cerebral Ischemia

Stroke is a disease that occurs due to a sudden interruption of the blood supply to the brain. It is a leading cause of death and disability worldwide. It is well-known that the immune system drives brain injury following an episode of ischemic stroke. The innate system and the adaptive system play distinct but synergistic roles following ischemia. The innate system can be activated by damage-associated molecular patterns (DAMPs), which are released from cells in the ischemic region. Damaged cells also release various other mediators that serve to increase inflammation and compromise the integrity of the blood–brain barrier (BBB). Within 24 h of an ischemic insult, the adaptive immune system is activated. This involves T cell and B cell-mediated inflammatory and humoral effects. These cells also stimulate the release of various interleukins and cytokines, which can modulate the inflammatory response. The adaptive immune system has been shown to contribute to a state of immunodepression following an ischemic episode, and this can increase the risk of infections. However, this phenomenon is equally important in preventing autoimmunity of the body to brain antigens that are released into the peripheral system as a result of BBB compromise. In this review, we highlight the key components of the adaptive immune system that are activated following cerebral ischemia.