Sleep Matters: CD4+ T Cell Memory Formation and the Central Nervous System

Interactions between sleep, inflammation, immunity and infections: A narrative review

BACKGROUND

Over the past decades, it has become increasingly evident that sleep disturbance contributes to inflammation-mediated disease, including depression, mainly through activation of the innate immune system and to an increased risk of infections.

METHODS

A comprehensive literature search was performed in PubMed to identify relevant research findings in the field of immunity, inflammation and infections, with a focus on translational research findings from the past 5 years.

RESULTS

Physiological sleep is characterized by a dynamic interplay between the immune system and sleep architecture, marked by increased innate immunity and T helper 1 (Th1) -mediated inflammation in the early phase, transitioning to a T helper 2 (Th2) response dominating in late sleep. Chronic sleep disturbances are associated with enhanced inflammation and an elevated risk of infections, while other inflammatory diseases may also be affected. Conversely, inflammation in response to infection can also disrupt sleep patterns and architecture. This narrative review summarizes current data on the complex relationships between sleep, immunity, inflammation and infections, while highlighting translational aspects. The bidirectional nature of these interactions are addressed within specific conditions such as sleep apnea, HIV, and other infections. Furthermore, technical developments with the potential to accelerate our understanding of these interactions are identified, including advances in wearable devices, artificial intelligence, and omics technology. By integrating these tools, novel biomarkers and therapeutic targets for sleep-related immune dysregulation may be identified.

CONCLUSION

The review underscores the importance of understanding and addressing immune imbalance related to sleep disturbances to improve disease outcomes.

Immune fitness and lifestyle habits of Saudi medical students: a cross sectional study

Introduction

Immune function reaches an optimum level in young adults. However, young adults are more likely to adopt potentially harmful habits that may pose a risk to their long-term health and immune fitness, and which eventually may put a substantial burden on the healthcare system. This study aimed to assess the status of medical students' immune fitness, using the immune status questionnaire (ISQ) and exploring the association with the commonly adopted lifestyle habits hypothesized to have an impact on immune functions.

Methods

A descriptive, cross-sectional study was conducted among preclinical students attending the medical school of King Abdulaziz University. An online self-reported questionnaire was used to assess the immune status (ISQ), perceived (momentary) immune fitness, general health, lifestyle habits and students' perception of these lifestyle-associated impacts on immune fitness. Descriptive, Spearman's correlation and stepwise linear regression analyses were performed.

Results

In a pooled sample of 211 participants, the overall ISQ score was 6.00 ± 5.0 with statistically significant abnormally lower scores in females (ISQ 5.00 ± 5.0, p < 0.001). 49.29% of respondents experienced poor immune fitness as measured by the ISQ (<6). The ISQ score was significantly correlated with fast and fatty food consumption (p = 0.003), daytime sleepiness (p = 0.001), and BMI subgroups (p = 0.028) negatively and positively correlated with adherence to a program of exercise (p = 0.005). A total of 41.23% of participants who reported a normal immune health, rated at ≥6 were graded below 6 on the ISQ score. Only 62.6% of students were able to correctly identify the effects of fast and fatty food consumption on immune fitness.

Conclusion

Poor immune fitness was common among medical students in KAU and associated significantly with their adopted lifestyle habits. Although, other factors can be significant contributors, biased immune health perception and lack of awareness of these lifestyle-associated impacts on immune fitness and general health may hinder the adoption of healthier habits. Immune biomarkers should be implemented in future work.

Characterization of glucose metabolism in breast cancer to guide clinical therapy

Background

Breast cancer (BRCA) ranks as a leading cause of cancer death in women worldwide. Glucose metabolism is a noticeable characteristic of the occurrence of malignant tumors. In this study, we aimed to construct a novel glycometabolism-related gene (GRG) signature to predict overall survival (OS), immune infiltration and therapeutic response in BRCA patients.

Materials and methods

The mRNA sequencing and corresponding clinical data of BRCA patients were obtained from public cohorts. Lasso regression was applied to establish a GRG signature. The immune infiltration was evaluated with the ESTIMATE and CIBERSORT algorithms. The drug sensitivity was estimated using the value of IC50, and further forecasted the therapeutic response of each patient. The candidate target was selected in Cytoscape. A nomogram was constructed via the R package of “rms”.

Results

We constructed a six-GRG signature based on CACNA1H, CHPF, IRS2, NT5E, SDC1 and ATP6AP1, and the high-risk patients were correlated with poorer OS (P = 2.515 × 10⁻⁷). M2 macrophage infiltration was considerably superior in high-risk patients, and CD8⁺ T cell infiltration was significantly higher in low-risk patients. Additionally, the high-risk group was more sensitive to Lapatinib. Fortunately, SDC1 was recognized as candidate target and patients had a better OS in the low-SDC1 group. A nomogram integrating the GRG signature was developed, and calibration curves were consistent between the actual and predicted OS.

Conclusions

We identified a novel GRG signature complementing the present understanding of the targeted therapy and immune biomarker in breast cancer. The GRGs may provide fresh insights for individualized management of BRCA patients.

Potential Role of Sleep Deficiency in Inducing Immune Dysfunction

Sleep deficiency and insomnia deteriorate the quality of patients’ lives, yet the exact influence of these factors on the immune system has only begun to gain interest in recent years. Growing evidence shows that insomnia is a risk factor for numerous diseases, including common infections and autoimmune diseases. Levels of inflammatory markers also seem to be abnormal in sleep deficient individuals, which may lead to low-grade inflammation. The interpretation of studies is difficult due to the equivocal term “sleep disturbances,” as well as due to the various criteria used in studies. This narrative review aims to summarize the available knowledge regarding the bidirectional influence of the immune system and sleep disturbances.

The splenic T cell receptor repertoire during an immune response against a complex antigen: Expanding private clones accumulate in the high and low copy number region

Large cellular antigens comprise a variety of different epitopes leading to a T cell response of extreme diversity. Therefore, tracking such a response by next generation sequencing of the T cell receptor (TCR) in order to identify common TCR properties among the expanding T cells represents an enormous challenge. In the present study we adapted a set of established indices to elucidate alterations in the TCR repertoire regarding sequence similarities between TCRs including VJ segment usage and diversity of nucleotide coding of a single TCR. We combined the usage of these indices with a new systematic splitting strategy regarding the copy number of the extracted clones to divide the repertoire into multiple fractions for separate analysis. We implemented this new analytic approach using the splenic TCR repertoire following immunization with sheep red blood cells (SRBC) in mice. As expected, early after immunization presumably antigen-specific clones accumulated in high copy number fractions, but at later time points similar accumulation of specific clones occurred within the repertoire fractions of lowest copy number. For both repertoire regions immunized animals could reliably be distinguished from control in a classification approach, demonstrating the robustness of the two effects at the individual level. The direction in which the indices shifted after immunization revealed that for both the early and the late effect alterations in repertoire parameters were caused by antigen-specific private clones displacing non-specific public clones. Taken together, tracking antigen-specific clones by their displacement of average TCR repertoire characteristics in standardized repertoire fractions ensures that our analytical approach is fairly independent from the antigen in question and thus allows the in-depth characterization of a variety of immune responses.

A Novel Inflammatory-Related Gene Signature Based Model for Risk Stratification and Prognosis Prediction in Lung Adenocarcinoma

Inflammation is an important hallmark of cancer and plays a role in both neogenesis and tumor development. Despite this, inflammatory-related genes (IRGs) remain to be poorly studied in lung adenocarcinoma (LUAD). We aim to explore the prognostic value of IRGs for LUAD and construct an IRG-based prognosis signature. The transcriptomic profiles and clinicopathological information of patients with LUAD were obtained from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO). Least absolute shrinkage and selection operator (LASSO) analysis and multivariate Cox regression were applied in the TCGA set to generate an IRG risk signature. LUAD cases with from the GSE31210 and GSE30219 datasets were used to validate the predictive ability of the signature. Analysis of the TCGA cohort revealed a five-IRG risk signature consisting of EREG, GPC3, IL7R, LAMP3, and NMUR1. This signature was used to divide patients into two risk groups with different survival rates. Multivariate Cox regression analysis verified that the risk score from the five-IRG signature negatively correlated with patient outcome. A nomogram was developed using the IRG risk signature and stage, with C-index values of 0.687 (95% CI: 0.644-0.730) in the TCGA training cohort, 0.678 (95% CI: 0.586-0.771) in GSE30219 cohort, and 0.656 (95% CI: 0.571-0.740) in GSE30219 cohort. Calibration curves were consistent between the actual and the predicted overall survival. The immune infiltration analysis in the TCGA training cohort and two GEO validation cohorts showed a distinctly differentiated immune cell infiltration landscape between the two risk groups. The IRG risk signature for LUAD can be used to predict patient prognosis and guide individual treatment. This risk signature is also a potential biomarker of immunotherapy.

Narcolepsy type 1 patients have lower levels of effector memory CD4+ T cells compared to their siblings when controlling for H1N1-(Pandemrix™)-vaccination and HLA DQB1∗06:02 status

STUDY OBJECTIVES

Evidence suggests a cell-mediated autoimmune pathogenesis for narcolepsy type 1 (NT1), but it is not clear whether the disease is associated with overall changes in T cell subsets. The increase in NT1 incidence after H1N1 vaccination campaign with the Pandemrix™ vaccine suggests that disease-relevant changes in the immune system following this vaccination were important. In this study, we aimed to investigate differentiated T cell subsets and levels of CD25 and CD69 activation markers in a cohort of mainly Pandemrix™-vaccinated NT1 patients compared with their vaccinated and unvaccinated siblings.

METHODS

Peripheral blood mononuclear cells were collected in parallel and analysed with flow cytometry in 31 NT1 patients with disease onset after the 2009 influenza A (H1N1) pandemic and/or Pandemrix™ vaccination and 45 of their non-narcoleptic siblings (29/31 and 34/45 vaccinated, respectively).

RESULTS

We observed significantly lower effector memory CD4⁺ T cell levels in NT1 patients compared to their siblings, when controlling for HLA DQB1∗06:02 and vaccination status. Further, within the sibling group, vaccination status significantly affected frequencies of central memory and CD8⁺CD25⁺ T cells, and HLA DQB1∗06:02 status significantly affected frequencies of CD4⁺CD25⁺ T cells.

CONCLUSION

We confirm that NT1 is associated with lower levels of effector memory CD4⁺ T cells in peripheral blood. Importantly, this finding was only significant when controlling for vaccination and HLA status in both patients and controls. We thus demonstrate the importance of characterizing such factors (eg HLA and vaccination) when studying T cell subsets in NT1. This might explain earlier conflicting results.

Association between allergic rhinitis-related factors and sleep duration in adolescents: Korea National Health and Nutrition Examination Survey V (2010-2012)

OBJECTIVES

Previous studies have shown that sleep and allergic rhinitis (AR) is closely associated, bidirectionally affecting each other. Adolescence is a period that adequate sleep is essential, and the burden of AR increases, both of which greatly affect the quality of life. The aim of the present study was to investigate the correlation between inappropriate sleep duration and each AR-related subjective/objective factor in Korean adolescents.

METHODS

We analyzed the data of 1936 adolescents aged between 12 and 18 years who participated in the Korea National Health and Nutrition Examination Survey from 2010 to 2012. Data on sleep duration, physician-diagnosed AR, and presence of rhinitis symptoms were collected using a self-administered questionnaire. Nasal endoscopic findings, including watery rhinorrhea and pale inferior turbinate mucosa, and aeroallergen sensitization based on serum specific immunoglobulin E levels were examined.

RESULTS

There was a higher prevalence of AR (23.68%) in the inappropriate sleep duration group than in the control group (16.56%; odds ratio = 1.56, p = 0.0024). The presence of endoscopic findings of AR showed a positive association with inappropriate sleep duration in males (odds ratio = 1.52, p = 0.008). In addition, in all three indoor allergens investigated, aeroallergen sensitization was not associated with inappropriate sleep duration.

CONCLUSION

Inappropriate sleep duration was associated with increased prevalence of AR in Korean adolescents. Especially, this association was relevant in nasal endoscopic findings in male.

Effects of sleep on the splenic milieu in mice and the T cell receptor repertoire recruited into a T cell dependent B cell response

Sleep is known to improve immune function ranging from cell distribution in the naïve state to elevated antibody titers after an immune challenge. The underlying mechanisms still remain unclear, partially because most studies have focused on the analysis of blood only. Hence, we investigated the effects of sleep within the spleen in female C57BL/6J mice with normal sleep compared to short-term sleep-deprived animals both in the naïve state and after an antigen challenge. Lack of sleep decreased the expression of genes associated with immune cell recruitment into and antigen presentation within the spleen both in the naïve state and during a T cell dependent B cell response directed against sheep red blood cells (SRBC). However, neither T cell proliferation nor formation of SRBC-specific antibodies was affected. In addition, the T cell receptor repertoire recruited into the immune response within seven days was not influenced by sleep deprivation. Thus, sleep modulated the molecular milieu within the spleen whereas we could not detect corresponding changes in the primary immune response against SRBC. Further studies will show whether sleep influences the secondary immune response against SRBC or the development of the B cell receptor repertoire, and how this can be compared to other antigens.

•

Sleep deprivation (SD) decreases expression of genes involved in T cell function.

•

SD induces those changes in the milieu of both lymph nodes and spleen.

•

SD dampens the expression of several genes in the spleen during an immune response.

•

SD does not alter the T cell receptor repertoire recruited into the immune response.

The Impact of Obesity and Lifestyle on the Immune System and Susceptibility to Infections Such as COVID-19

Background: COVID-19 is a global challenge to healthcare. Obesity is common in patients with COVID-19 and seems to aggravate disease prognosis. In this review we explore the link between obesity, chronic disease, lifestyle factors and the immune system, and propose societal interventions to enhance global immunity. Search Strategy and Selection Criteria: We performed three literature searches using the keywords (1) coronavirus AND comorbidities, (2) comorbidities AND immune system, and (3) lifestyle factors AND immune system. Results were screened for relevance by the main author and a total of 215 articles were thoroughly analyzed. Results: The relationship between obesity and unfavorable COVID-19 prognosis is discussed in light of the impact of chronic disease and lifestyle on the immune system. Several modifiable lifestyle factors render us susceptible to viral infections. In this context, we make a case for fostering a healthy lifestyle on a global scale. Conclusions: Obesity, additional chronic disease and an unhealthy lifestyle interactively impair immune function and increase the risk of severe infectious disease. In adverse metabolic and endocrine conditions, the immune system is geared toward inflammation. Collective effort is needed to ameliorate modifiable risk factors for obesity and chronic disease on a global scale and increase resistance to viruses like SARS-CoV-2.