Severe COVID-19 and long COVID are associated with high expression of STING, cGAS and IFN-α

Abstract:

The cGAS-STING pathway appears to contribute to dysregulated inflammation during coronavirus disease 2019 (COVID-19); however, inflammatory factors related to long COVID are still being investigated.

In the present study, we evaluated the association of cGAS and STING gene expression levels and plasma IFN-α, TNF-α and IL-6 levels with COVID-19 severity in acute infection and long COVID, based on analysis of blood samples from 148 individuals, 87 with acute COVID-19 and 61 in the post-COVID-19 period.

Quantification of gene expression was performed by real-time PCR, and cytokine levels were quantified by ELISA and flow cytometry. In acute COVID-19, cGASSTING, IFN-α, TNF-α, and IL-6 levels were higher in patients with severe disease than in those with nonsevere manifestations (p < 0.05). Long COVID was associated with elevated cGASSTING and IFN-α levels (p < 0.05).

Activation of the cGAS-STING pathway may contribute to an intense systemic inflammatory state in severe COVID-19 and, after infection resolution, induce an autoinflammatory disease in some tissues, resulting in long COVID.

Source: Queiroz, M.A.F., Brito, W.R.S., Pereira, K.A.S. et al. Severe COVID-19 and long COVID are associated with high expression of STINGcGAS and IFN-α. Sci Rep 14, 4974 (2024). https://doi.org/10.1038/s41598-024-55696-0 https://www.nature.com/articles/s41598-024-55696-0 (Full text)

Research progress on central mechanism of acupuncture treatment for chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome is a neurological disorder characterized by extreme fatigue that lasts for a long time and doesn’t alleviate with rest. The number of the cases has been increasing during the era of COVID-19 pandemic.

Acupuncture may have some effect on chronic fatigue syndrome, but its mechanism remains unclear. This article was to summarize the specific manifestations of abnormal central mechanism in patients with chronic fatigue syndrome through laboratory tests and neuroimaging.

It was found from the laboratory evaluation that there were changes in the structure of the frontal cortex, thalamus and other brain tissues; factors, including IFN-α and IL-10 in cerebrospinal fluid were found abnormal; results of oxidative and nitrosative stress and changes in neurobiochemical substances, e.g. hypothalamus hormone levels and neurotransmitter concentrations, were observed.

With magnetic resonance imaging and positron emission tomography, it was shown that the partial brain of persons with chronic fatigue syndrome had morphological changes with diminished grey matter and white; changes in cerebral blood flow velocity caused by decreased perfusion and functional activity with abnormal connectivity in brain were detected.

In addition, there was significant decrease in glucose metabolism accompanied with neuroinflammatory response; metabolic disorders of serotonergic, cholinergic, glutamatergic and γ-aminobutyric acid energy neurotransmitters were also discovered.

The regulatory effect of acupuncture on the above central neurological abnormalities in chronic fatigue syndrome model animals was elaborated, and the direction for further research was analyzed in order to provide ideas for further research on the central mechanism of acupuncture treatment for chronic fatigue syndrome.

Source: Li BB, Feng CW, Qu YY, Sun ZR, Chen T, Wang YL, Wang QY, Lu J, Shao YY, Yang TS. Research progress on central mechanism of acupuncture treatment for chronic fatigue syndrome. World J Acupunct Moxibustion.  doi: 10.1016/j.wjam.2023.03.002 [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10061266/ (Full text)

Transcriptional reprogramming from innate immune functions to a pro-thrombotic signature by monocytes in COVID-19

Abstract:

Although alterations in myeloid cells have been observed in COVID-19, the specific underlying mechanisms are not completely understood. Here, we examine the function of classical CD14+ monocytes in patients with mild and moderate COVID-19 during the acute phase of infection and in healthy individuals.

Monocytes from COVID-19 patients display altered expression of cell surface receptors and a dysfunctional metabolic profile that distinguish them from healthy monocytes. Secondary pathogen sensing ex vivo leads to defects in pro-inflammatory cytokine and type-I IFN production in moderate COVID-19 cases, together with defects in glycolysis.

COVID-19 monocytes switch their gene expression profile from canonical innate immune to pro-thrombotic signatures and are functionally pro-thrombotic, both at baseline and following ex vivo stimulation with SARS-CoV-2. Transcriptionally, COVID-19 monocytes are characterized by enrichment of pathways involved in hemostasis, immunothrombosis, platelet aggregation and other accessory pathways to platelet activation and clot formation. These results identify a potential mechanism by which monocyte dysfunction may contribute to COVID-19 pathology.

Source: Maher AK, Burnham KL, Jones EM, Tan MMH, Saputil RC, Baillon L, Selck C, Giang N, Argüello R, Pillay C, Thorley E, Short CE, Quinlan R, Barclay WS, Cooper N, Taylor GP, Davenport EE, Dominguez-Villar M. Transcriptional reprogramming from innate immune functions to a pro-thrombotic signature by monocytes in COVID-19. Nat Commun. 2022 Dec 26;13(1):7947. doi: 10.1038/s41467-022-35638-y. PMID: 36572683; PMCID: PMC9791976. https://www.nature.com/articles/s41467-022-35638-y (Full text)

SARS-CoV-2-specific T cells associate with inflammation and reduced lung function in pulmonary post-acute sequalae of SARS-CoV-2

Abstract:

As of January 2022, at least 60 million individuals are estimated to develop post-acute sequelae of SARS-CoV-2 (PASC) after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While elevated levels of SARS-CoV-2-specific T cells have been observed in non-specific PASC, little is known about their impact on pulmonary function which is compromised in the majority of these individuals. This study compares frequencies of SARS-CoV-2-specific T cells and inflammatory markers with lung function in participants with pulmonary PASC and resolved COVID-19 (RC).

Compared to RC, participants with respiratory PASC had between 6- and 105-fold higher frequencies of IFN-γ- and TNF-α-producing SARS-CoV-2-specific CD4+ and CD8+ T cells in peripheral blood, and elevated levels of plasma CRP and IL-6. Importantly, in PASC participants the frequency of TNF-α-producing SARS-CoV-2-specific CD4+ and CD8+ T cells, which exhibited the highest levels of Ki67 indicating they were activity dividing, correlated positively with plasma IL-6 and negatively with measures of lung function, including forced expiratory volume in one second (FEV1), while increased frequencies of IFN-γ-producing SARS-CoV-2-specific T cells associated with prolonged dyspnea.

Statistical analyses stratified by age, number of comorbidities and hospitalization status demonstrated that none of these factors affect differences in the frequency of SARS-CoV-2 T cells and plasma IL-6 levels measured between PASC and RC cohorts. Taken together, these findings demonstrate elevated frequencies of SARS-CoV-2-specific T cells in individuals with pulmonary PASC are associated with increased systemic inflammation and decreased lung function, suggesting that SARS-CoV-2-specific T cells contribute to lingering pulmonary symptoms. These findings also provide mechanistic insight on the pathophysiology of PASC that can inform development of potential treatments to reduce symptom burden.

Source: Katherine M. Littlefield,Renée O. Watson,Jennifer M. Schneider,Charles P. Neff,Eiko Yamada,Min Zhang,Thomas B. Campbell,Michael T. Falta,Sarah E. Jolley,Andrew P. Fontenot,Brent E. Palmer. SARS-CoV-2-specific T cells associate with inflammation and reduced lung function in pulmonary post-acute sequalae of SARS-CoV-2. PLOS Pathogens. Published: May 26, 2022 https://doi.org/10.1371/journal.ppat.1010359  (Full text)

Autoantibodies against apolipoprotein A-1 after COVID-19 predict symptoms persistence

Abstract:

Background: SARS-CoV-2 infection triggers different auto-antibodies, including anti-apolipoprotein A-1 IgGs (AAA1), which could be of concern as mediators of persistent symptoms. We determined the kinetics of AAA1 response over after COVID-19, and the impact of AAA1 on the inflammatory response and symptoms persistence.

Methods: All serologies were assessed at one, three, six, and twelve months in 193 hospital employees with COVID-19. ROC curve analyses and logistic regression models (LRM) were used to determine the prognostic accuracy of AAA1 and their association with patient-reported COVID-19 symptoms persistence at 12 months. Interferon (IFN)-α and-γ production by AAA1-stimulated human monocyte-derived macrophages (HMDM) was assessed in vitro.

Results: AAA1 seropositivity was 93% at one month and declined to 15% at 12 months after COVID-19. Persistent symptoms at 12 months were observed in 45.1% of participants, with a predominance of neurological (28.5%), followed by general (15%) and respiratory symptoms (9.3%). Over time, strength of correlations between AAA1 and anti-SARS-COV2 serologies decreased, but remained significant. From the 3rd month on, AAA1 levels predicted persistent respiratory symptoms (area under the curves 0.72-0.74; p<0.001), independently of disease severity, age and gender (adjusted odds ratios 4.81-4.94; p=0.02), while anti-SARS-CoV-2 serologies did not. AAA1 increased IFN-α production by HMDMs (p=0.03), without affecting the IFN-γ response.

Conclusion: COVID-19 induces a marked though transient AAA1 response, independently predicting one-year persistence of respiratory symptoms. By increasing IFN-α response, AAA1 may contribute to persistent symptoms. If and how AAA1 levels assessment could be of use for COVID-19 risk stratification remains to be determined

Source: L’Huillier AG, Pagano S, Baggio S, Meyer B, Andrey DO, Nehme M, Guessous I, Eberhardt CS, Huttner A, Posfay-Barbe KM, Yerly S, Siegrist CA, Kaiser L, Vuilleumier N. Autoantibodies against apolipoprotein A-1 after COVID-19 predict symptoms persistence. Eur J Clin Invest. 2022 May 22:e13818. doi: 10.1111/eci.13818. Epub ahead of print. PMID: 35598178.  https://pubmed.ncbi.nlm.nih.gov/35598178/ (Full text available as PDF file)

Activation of Transposable Elements in Immune Cells of Fibromyalgia Patients

Abstract:

Advancements in nucleic acid sequencing technology combined with an unprecedented availability of metadata have revealed that 45% of the human genome constituted by transposable elements (TEs) is not only transcriptionally active but also physiologically necessary. Dysregulation of TEs, including human retroviral endogenous sequences (HERVs) has been shown to associate with several neurologic and autoimmune diseases, including Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). However, no study has yet addressed whether abnormal expression of these sequences correlates with fibromyalgia (FM), a disease frequently comorbid with ME/CFS.

The work presented here shows, for the first time, that, in fact, HERVs of the H, K and W types are overexpressed in immune cells of FM patients with or without comorbid ME/CFS. Patients with increased HERV expression (N = 14) presented increased levels of interferon (INF-β and INF-γ) but unchanged levels of TNF-α. The findings reported in this study could explain the flu-like symptoms FM patients present with in clinical practice, in the absence of concomitant infections. Future work aimed at identifying specific genomic loci differentially affected in FM and/or ME/CFS is warranted.

Source: Ovejero T, Sadones O, Sánchez-Fito T, Almenar-Pérez E, Espejo JA, Martín-Martínez E, Nathanson L, Oltra E. Activation of Transposable Elements in Immune Cells of Fibromyalgia Patients. Int J Mol Sci. 2020 Feb 18;21(4). pii: E1366. doi: 10.3390/ijms21041366. https://www.mdpi.com/1422-0067/21/4/1366 (Full text)

Persistent fatigue induced by interferon-alpha: a novel, inflammation-based, proxy model of chronic fatigue syndrome

Abstract:

The role of immune or infective triggers in the pathogenesis of Chronic Fatigue Syndrome (CFS) is not yet fully understood. Barriers to obtaining immune measures at baseline (i.e., before the trigger) in CFS and post-infective fatigue model cohorts have prevented the study of pre-existing immune dysfunction and subsequent immune changes in response to the trigger. This study presents interferon-alpha (IFN-α)-induced persistent fatigue as a model of CFS. IFN-α, which is used in the treatment of chronic Hepatitis C Virus (HCV) infection, induces a persistent fatigue in some individuals, which does not abate post-treatment, that is, once there is no longer immune activation. This model allows for the assessment of patients before and during exposure to the immune trigger, and afterwards when the original trigger is no longer present.

Fifty-five patients undergoing IFN-α treatment for chronic HCV were assessed at baseline, during the 6-12 months of IFN-α treatment, and at six-months post-treatment. Measures of fatigue, cytokines and kynurenine pathway metabolites were obtained. Fifty-four CFS patients and 57 healthy volunteers completed the same measures at a one-off assessment, which were compared with post-treatment follow-up measures from the HCV patients. Eighteen patients undergoing IFN-α treatment (33%) were subsequently defined as having ‘persistent fatigue’ (the proposed model for CFS), if their levels of fatigue were higher six-months post-treatment than at baseline; the other 67% were considered ‘resolved fatigue’.

Patients who went on to develop persistent fatigue experienced a greater increase in fatigue symptoms over the first four weeks of IFN-α, compared with patients who did not (Δ Treatment Week (TW)-0 vs. TW4; PF: 7.1 ± 1.5 vs. RF: 4.0 ± 0.8, p = 0.046). Moreover, there was a trend towards increased baseline interleukin (IL)-6, and significantly higher baseline IL-10 levels, as well as higher levels of these cytokines in response to IFN-α treatment, alongside concurrent increases in fatigue. Levels increased to more than double those of the other patients by Treatment Week (TW)4 (p =  0.011 for IL-6 and p = 0.001 for IL-10).

There was no evidence of an association between persistent fatigue and peripheral inflammation six-months post-treatment, nor did we observe peripheral inflammation in the CFS cohort. While there were changes in kynurenine metabolites in response to IFN-α, there was no association with persistent fatigue. CFS patients had lower levels of the ratio of kynurenine to tryptophan and 3-hydroxykynurenine than controls. Future studies are needed to elucidate the mechanisms behind the initial exaggerated response of the immune system in those who go on to experience persistent fatigue even if the immune trigger is no longer present, and the change from acute to chronic fatigue in the absence of continued peripheral immune activation.

Source: Russell A, Hepgul N, Nikkheslat N, Borsini A, Zajkowska Z, Moll N, Forton D, Agarwal K, Chalder T, Mondelli V, Hotopf M, Cleare A, Murphy,  G, Foster G, Wong T, Schütze GA, Schwarz MJ, Harrison N, Zunszain PA, Pariante CM. Persistent fatigue induced by interferon-alpha: a novel, inflammation-based, proxy model of chronic fatigue syndrome. Psychoneuroendocrinology. 2018 Dec 14. pii: S0306-4530(18)30196-3.  doi: 10.1016/j.psyneuen.2018.11.032. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/30567628

Molecular signatures of peripheral blood mononuclear cells during chronic interferon-α treatment: relationship with depression and fatigue

Abstract:

BACKGROUND: Interferon-alpha (IFN-α) treatment for infectious disease and cancer causes high rates of depression and fatigue, and has been used to investigate the impact of inflammatory cytokines on brain and behavior. However, little is known about the transcriptional impact of chronic IFN-α on immune cells in vivo and its relationship to IFN-α-induced behavioral changes.

METHOD: Genome-wide transcriptional profiling was performed on peripheral blood mononuclear cells (PBMCs) from 21 patients with chronic hepatitis C virus (HCV) either awaiting IFN-α therapy (n=10) or at 12 weeks of IFN-α treatment (n=11).

RESULTS: Significance analysis of microarray data identified 252 up-regulated and 116 down-regulated gene transcripts. Of the up-regulated genes, 2′-5′-oligoadenylate synthetase 2 (OAS2), a gene linked to chronic fatigue syndrome (CFS), was the only gene that was differentially expressed in patients with IFN-α-induced depression/fatigue, and correlated with depression and fatigue scores at 12 weeks (r=0.80, p=0.003 and r=0.70, p=0.017 respectively). Promoter-based bioinformatic analyses linked IFN-α-related transcriptional alterations to transcription factors involved in myeloid differentiation, IFN-α signaling, activator protein-1 (AP1) and cAMP responsive element binding protein/activation transcription factor (CREB/ATF) pathways, which were derived primarily from monocytes and plasmacytoid dendritic cells. IFN-α-treated patients with high depression/fatigue scores demonstrated up-regulation of genes bearing promoter motifs for transcription factors involved in myeloid differentiation, IFN-α and AP1 signaling, and reduced prevalence of motifs for CREB/ATF, which has been implicated in major depression.

CONCLUSIONS: Depression and fatigue during chronic IFN-α administration were associated with alterations in the expression (OAS2) and transcriptional control (CREB/ATF) of genes linked to behavioral disorders including CFS and major depression, further supporting an immune contribution to these diseases.

 

Source: Felger JC, Cole SW, Pace TW, Hu F, Woolwine BJ, Doho GH, Raison CL, Miller AH. Molecular signatures of peripheral blood mononuclear cells during chronic interferon-α treatment: relationship with depression and fatigue. Psychol Med. 2012 Aug;42(8):1591-603. doi: 10.1017/S0033291711002868. Epub 2011 Dec 9.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3433045/ (Full article)

 

Chronic fatigue syndrome: identification of distinct subgroups on the basis of allergy and psychologic variables

Abstract:

BACKGROUND: We investigated a role for allergic inflammation and psychologic parameters in the development of chronic fatigue syndrome (CFS).

METHODS: The design was a comparison between subjects with CFS and age- and sex-matched control cohorts. Studies were performed on CFS subjects (n = 18) and control cohorts consisting of normal subjects (n = 11), allergic subjects (n = 14), and individuals with primary depression (n = 12). We quantified cytokines at baseline as cell-associated immunoreactive peptides and as transcripts evaluated by means of semiquantitative RNA-based polymerase chain reactions. Psychologic evaluations included administration of the Diagnostic Interview Schedule, the Structured Clinical Interview, and the Symptom Checklist 90-Revised.

RESULTS: Increases in tumor necrosis factor (TNF)-alpha were identified in individual subjects with CFS (50.1 +/- 14.4 pg TNF-alpha per 10(7) peripheral blood mononuclear cells [PBMCs]; mean +/- SEM) and allergic subjects (41.6 +/- 7.6) in comparison with normal subjects (13.1 +/- 8.8) (P < .01 and P < .05, respectively). Similar trends were observed for interferon (IFN)-alpha in allergic subjects (3.0 +/- 1.7 pg/10(7) PBMCs) and subjects with CFS (6.4 +/- 3.4) compared with normal subjects (1.9 +/- 1.4). A significant increase (P < .05) in TNF-alpha transcripts was demonstrated between subjects with CFS and depressed subjects. In contrast to these proinflammatory cytokines, both subjects with CFS (2.6 +/- 1.8 pg/10(7) PBMCs) and allergic subjects (3.4 +/- 2.8) were associated with a statistically significant (P < .01) decrease in IL-10 concentrations compared with normal subjects (60.2 +/- 18.2). As shown in other studies, most of our subjects with CFS were allergic (15 of 18) and therefore presumably demonstrated cytokine gene activation on that basis. The seasonal exacerbation of allergy was associated with a further increase in cellular IFN-alpha (from 2.1 +/- 1.2 to 14.2 +/- 4.5 pg/107 PBMCs; P < .05) but no further modulation of TNF-alpha or IL-10. Similarly, self-reported exacerbations of CFS were associated with a further increase in IFN-alpha (from 2.5 +/- 1.0 to 21.9 +/- 7.8; P < .05) and occurred at times of seasonal exposures to allergens. This linkage does not permit making any definitive conclusions regarding a causative influence of either seasonal allergies or the increase in cellular IFN-alpha with the increase in CFS symptoms. The close association between atopy and CFS led us to speculate that CFS may arise from an abnormal psychologic response to the disordered expression of these proinflammatory and antiinflammatory cytokines. Psychologic variables were predictive of immune status within the CFS sample (65.9% of the variance in immune status; F (3,10) = 6.44, P < .05). Specifically, the absence of a personality disorder but greater endorsement of global psychiatric symptoms was predictive of immune activation.

CONCLUSIONS: Most of our subjects with CFS were allergic, and the CFS and allergy cohorts were similar in terms of their immune status. However, the CFS subjects could be discriminated by the distinct psychologic profiles among subjects with and without immune activation. We propose that in at least a large subgroup of subjects with CFS who had allergies, the concomitant influences of immune activation brought on by allergic inflammation in an individual with the appropriate psychologic profile may interact to produce the symptoms of CFS. In a psychologically predisposed individual, symptoms associated with allergic inflammation are recognized as illness.

 

Source: Borish L, Schmaling K, DiClementi JD, Streib J, Negri J, Jones JF. Chronic fatigue syndrome: identification of distinct subgroups on the basis of allergy and psychologic variables. J Allergy Clin Immunol. 1998 Aug;102(2):222-30. http://www.ncbi.nlm.nih.gov/pubmed/9723665

 

alpha-Interferon treatment of patients with chronic fatigue syndrome

Abstract:

Thirty patients who fulfilled clinical criteria defined by the CDC for Chronic Fatigue Syndrome were treated with alfa 2a interferon or placebo in a double-blind crossover study. Outcome was evaluated by Natural Killer (NK) cell function, lymphocyte proliferation to mitogens and soluble antigens, CD4/CD8 counts and a 10 item Quality of Life (QOL) survey.

Although mean NK function rose from 87.8 +/- 19.6 to 129.3 +/- 20.7 lytic untis (LU; p < .05) with 12 weeks of interferon therapy, there was no significant change in the other immunologic parameters or QOL scores. When the 26 patients who completed the study were stratified according to their baseline NK function and lymphocyte proliferation, 4 groups were identified: 3 patients had normal NK cell function and lymphocyte proliferation when compared to normal, healthy controls, 9 had isolated deficiency in lymphocyte proliferation, 7 had diminished NK function only, and 7 had abnormalities for both parameters.

QOL scores were not significantly different for the four groups at baseline. After 12 weeks of interferon therapy, QOL score significantly improved in each of the seven patients with isolated NK cell dysfunction (mean score, 16.3 +/- 7.9) compared to baseline (39.7 +/- 12.1; p < .05). In these patients the mean NK function increased from 35.1 +/- 11.7 to 91.5 +/- 22.7 LU (p < .01). Significant improvement was not recorded for QOL in the other three groups. Thus, therapy with alpha interferon has a significant effect on the QOL of that subgroup of patients with CFS manifesting an isolated decrease in NK function.

 

Source: See DM, Tilles JG. alpha-Interferon treatment of patients with chronic fatigue syndrome. Immunol Invest. 1996 Jan-Mar;25(1-2):153-64. http://www.ncbi.nlm.nih.gov/pubmed/8675231