Heat-shock protein 65 and activated gamma/delta T cells in injured arteries

Identification of Hub Genes and Immune Infiltration in Coronary Artery Disease: A Risk Prediction Model

Purpose

Our study aimed to establish a prediction model for coronary artery disease (CAD) that integrates immune infiltration and a gene expression signature.

Methods

613 differentially expressed genes (DEGs) and 12 hub genes were screened via the GSE113079 dataset. The pathway enrichment analysis indicated that these genes (613 DEGs and 12 hub genes) were closely associated with the inflammatory and immune responses. Based on the differentially expressed miRNA (DEmiRNA)-DEG regulatory network and immune cell infiltration, the Lasso algorithm constructed a CAD risk prediction model containing the risk score and immune score. Then, ROC-AUC and polymerase chain reaction (PCR) were performed for validation.

Results

Six hub genes (PTGER1, PIK3R1, ADRA2A, CORT, CXCL12, and S1PR5) had a high distinguishing capability (AUC > 0.90). In addition, the miRNAs targeting 12 hub genes were predicted and intersected with the DEmiRNAs, and the DEmiRNA-DEG regulatory network was then constructed. Two LASSO models and a novel CAD risk prediction model were constructed through LASSO regression analysis, and they both accurately obtained the risk of CAD. The CAD risk prediction model shows good performance (AUC = 0.988). We also constructed a valid nomogram, and PCR results verified three downregulation hub genes and one upregulation gene in the CAD risk model.

Conclusion

We demonstrated the molecular mechanism of the hub genes in CAD and provided a valuable tool for predicting the risk of CAD.

The Changes in the Quantity of Lymphocyte Subpopulations during the Process of Sepsis

Sepsis remains a global challenge, especially in low- and middle-income countries, where there is an urgent need for easily accessible and cost-effective biomarkers to predict the occurrence and prognosis of sepsis. Lymphocyte counts are easy to measure clinically, and a large body of animal and clinical research has shown that lymphocyte counts are closely related to the incidence and prognosis of sepsis. This review extensively collected experimental articles related to lymphocyte counts since the unification of the definition of sepsis. The article categorizes and discusses the relationship between absolute lymphocyte counts, intrinsic lymphocyte subsets, effector T-lymphocytes, B-lymphocytes, dendritic cells, and the incidence and prognosis of sepsis. The results indicate that comparisons of absolute lymphocyte counts alone are meaningless. However, in addition to absolute lymphocyte counts, innate lymphocyte subsets, effector T-cells, B-lymphocytes, and dendritic cells have shown certain research value in related studies.

Paying for the Tolls: The High Cost of the Innate Immune System for the Cardiac Myocyte

The cardiac myocyte differs strikingly from the specialized cells of the immune system, which has two different responses to invading organisms and tissue damage. Adaptive or acquired immunity generates highly specific antibodies in response to threats and is an essential component of immunity; however, adaptive immunity can take 4-7 days to mobilize, and a more primitive response, innate immunity, fills the gap. Innate immunity is expressed in complex and in primitive life forms. Specialized receptors, Toll-like receptors (TLRs), which are widely distributed throughout different tissues recognize danger signals and rapidly respond with the release of noxious substances, such as TNFα. The problem is that many endogenous molecules have been found to act as ligands for specific TLRs, and when these molecules are released into the extracellular environment, they can cause problems by activating innate immunity and an inflammatory response. In cardiac myocytes heat shock protein (HSP)60 can activate TLR4, as can HMGB1, and this type of response can amplify the response to ischemia/reperfusion leading to increased cell and tissue injury. Activation of TLRs can potentially amplify chronic, inflammatory diseases, such as ischemic heart failure. Thus, it is important to understand the regulation of the TLRs and their downstream effects. This chapter will focus on the TLRs and cardiac myocytes.

Early activation of gammadelta T lymphocytes in patients with severe systemic inflammatory response syndrome

Innate immunity plays an important role in host defense after severe insult. gammadelta T lymphocytes are recognized as the first line of defense against microbial invasion. In this study, we evaluated gammadelta T lymphocytes in the peripheral blood of patients with severe systemic inflammatory response syndrome (SIRS), and examined on role of these cells. Thirty-seven patients with severe SIRS (SIRS criteria and serum C-reactive protein > or = 10 mg/dL) and 27 healthy volunteers were studied. Severe SIRS was caused by trauma in 14 patients (Injury Severity Score of 30.1 +/- 10.8) and by sepsis in 23 patients. The counts of gammadelta and alphabeta T lymphocytes were determined by flow cytometry of cells stained with monoclonal antibodies to gammadelta and alphabeta T lymphocyte receptors. The activation of these cells was evaluated by flow cytometry of cells stained with monoclonal antibodies to CD69 and HLA-DR. Serial counts and activation of gammadelta and alphabeta T lymphocytes were also determined in eight trauma patients (Injury Severity Score of 31.0 +/- 13.5) during a 2-week observation period. The count of gammadelta T lymphocytes in the peripheral blood of SIRS patients (30.1 +/- 6.0/microL) was significantly lower (P < 0.05) than that of the healthy volunteers (104.3 +/- 10.9/microL). The expression of CD69, an index of early activation of T lymphocytes, was significantly greater on gammadelta T lymphocytes from SIRS patients (patients 23.9% +/- 3.4%, healthy controls 4.8% +/- 0.6%, P < 0.05). In trauma patients, the expression of CD69 on gammadelta T lymphocytes increased rapidly within 48 h after injuries. In conclusion, gammadelta T lymphocytes are activated and decreased in the peripheral blood of severe SIRS patients. In trauma patients, the activation of gammadelta T lymphocytes occurs in the fairly acute phase after injuries. These results suggest a significant role for gammadelta T lymphocytes as early responders after severe insult.

Phenotypic and functional characterization of blood gammadelta T cells in sleep apnea

Hypoxia-induced lymphocyte dysfunction may be implicated in endothelial cell damage in obstructive sleep apnea (OSA) syndrome. gammadelta T cells' unique migration, cytotoxic features, and accumulation in atherosclerotic plaques are considered critical in cardiovascular disorders. We characterized the phenotype, cytokine profile, adhesion properties, and cytotoxicity of gammadelta T cells in patients with OSA and control subjects. The following is a summary of our major findings regarding OSA gammadelta T cells: (1) a significant increase in the expression of the inhibitory natural killer B1 receptors was found; (2) the intracellular content of proinflammatory cytokines tumor necrosis factor (TNF)-alpha and interleukin-8 was increased, and the content of the antiinflammatory cytokine interleukin-10 was decreased; (3) gammadelta T cells of patients with OSA adhered significantly more avidly to nonactivated endothelial cells in culture than those of control subjects; (4) L-selectin expression was higher; (5) anti-E/P-selectin antibodies and anti-TNF-alpha antibodies decreased the adhesion index of OSA gammadelta T lymphocytes/endothelial cells but not of control subjects; and (6) cytotoxicity of OSA gammadelta T lymphocytes against endothelial cells in culture was 2.5-fold higher than that of control subjects and could be prevented by pretreatment with anti-TNF-alpha. Collectively these data implicate gammadelta T lymphocyte function in atherogenic sequelae in OSA.

Role of immunocompetent cells in nonimmune renal diseases

Renal infiltration with macrophages and monocytes is a well-recognized feature of not only immune, but also nonimmune kidney disease. This review focuses on the investigations that have shown accumulation of immunocompetent cells in experimental models of acute and chronic ischemia, protein overload, hypercholesterolemia, renal ablation, obstructive uropathy, polycystic kidney disease, diabetes, aging, murine hypertension, and nephrotoxicity. We examine the mechanisms of infiltration of immunocompetent cells and their participation in the self-perpetuating cycle of activation of the angiotensin system, generation of reactive oxygen species, and further recruitment of monocytes and lymphocytes. We also discuss the possibility of antigen-dependent and antigen-independent mechanisms of immune cell activation in these animal models. Finally, we review the recent studies in which suppression of cellular immunity with mycophenolate mofetil has proven beneficial in attenuating or preventing the progression of renal functional and histologic damage in experimental conditions of nonimmune nature.

Stress proteins and atherosclerosis

Several cytotoxic stimuli of a different nature are involved in the complex etiology of atherosclerosis. Cells of the vasculature may potentially cope with the presence of these stressors through the increased synthesis of stress proteins (or heat shock proteins, hsps), an ubiquitous and conserved defense response. Evidence exists that the expression of two stress proteins of intermediate molecular weight, hsp60 and hsp70, is higher at sites of atherosclerotic lesions than it is in normal tissue. The role of hsps in atherosclerosis is controversial. While hsp70 is likely to be involved in cytoprotection, hsp60 is probably acting as an autoantigen, and may trigger both cell-mediated and antibody-mediated immune responses.

Changes of serum antibodies to heat-shock protein 65 in coronary heart disease and acute myocardial infarction

Accumulating evidence indicates the involvement of heat shock proteins (hsp), a family of stress-inducible proteins, in atherosclerosis. For carotid atherosclerosis an association with an increase in hsp65 antibodies has been demonstrated. To investigate whether such antibodies are also associated with coronary heart disease (CHD) and acute myocardial infarction (MI), an age- and sex-matched study with patients suffering from CHD (n = 114) and MI (n = 89) and healthy controls (n = 76) was performed. All study participants (n = 279) were consecutively recruited according to typical diagnostic criteria. Determination of antibody titres to hsp65 was performed by an enzyme-linked immunosorbent assay (ELISA). Hsp65 antibody titres in CHD showed a significant increase compared to the healthy control group (P = 0.029), however, hsp65 antibody titres were found to be significantly lower in acute MI, compared to CHD (P = 0.005). Alteration in hsp65 antibody titres showed no correlation to established cardiovascular risk factors, e.g. serum total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, blood pressure, smoking, alcohol intake and body weight. In conclusion, serum concentrations of hsp65 antibodies were elevated independently in coronary heart diseases and declined in patients with acute myocardial infarction, indicating a possible involvement of the antibodies in the pathogenesis of this disease.

The role of heat shock proteins in protection and pathophysiology of the arterial wall

The arterial wall is an integrated functional component of the circulatory system that is continually remodelling in response to various stressors, including localized injury, toxins, smoking and hypercholesterolaemia. These stimuli directly or indirectly cause changes in blood pressure and damage to the vessel wall, and eventually induce arterial stiffness and obstruction. To maintain the homeostasis of the vessel wall, the vascular cells produce a high level of stress proteins, also known as heat shock proteins, which protect against damage during haemodynamic stress. However, an immune reaction to heat shock proteins might contribute to the development of atherosclerosis. We hypothesize that the induction of heat shock proteins is beneficial in the arterial wall's response to stress but is harmful in certain other circumstances.