NK cells – Page 4 – American ME and CFS Society

ERK1/2, MEK1/2 and p38 downstream signalling molecules impaired in CD56 dim CD16+ and CD56 bright CD16 dim/- natural killer cells in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis patients

Abstract:

BACKGROUND: Natural Killer (NK) cell effector functions are dependent on phosphorylation of the mitogen-activated protein kinases (MAPK) pathway to produce an effective immune response for the clearance of target cells infected with viruses, bacteria or malignantly transformed cells. Intracellular signals activating NK cell cytokine production and cytotoxic activity are propagated through protein phosphorylation of MAPKs including MEK1/2, ERK1/2, p38 and JNK. Reduced NK cell cytotoxic activity is consistently reported in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) patients and intracellular signalling by MAPK in NK cells remains to be investigated. Therefore, the purpose of this paper was to investigate MAPK downstream signalling molecules in NK cell phenotypes from CFS/ME patients.

METHODS: Flow cytometric protocols were used to measure phosphorylation of the MAPK pathway in CD56(bright)CD16(dim/-) and CD56(dim)CD16(+) NK cells following stimulation with K562 tumour cells or phorbol-12-myristate-13-acetate plus ionomycin. NK cell cytotoxic activity, degranulation, lytic proteins and cytokine production were also measured as markers for CD56(bright)CD16(dim/-) and CD56(dim)CD16(+) NK cell function using flow cytometric protocols.

RESULTS: CFS/ME patients (n = 14) had a significant decrease in ERK1/2 in CD56(dim)CD16(+) NK cells compared to the non-fatigued controls (n = 11) after incubation with K562 cells. CD56(bright)CD16(dim/-) NK cells from CFS/ME patients had a significant increase in MEK1/2 and p38 following incubation with K562 cells.

CONCLUSIONS: This is the first study to report significant differences in MAPK intracellular signalling molecules in CD56(dim)CD16(+) and CD56(bright)CD16(dim/-) NK cells from CFS/ME patients. The current results highlight the importance of intracellular signalling through the MAPK pathway for synergistic effector function of CD56(dim)CD16(+) and CD56(bright)CD16(dim/-) NK cells to ensure efficient clearance of target cells. In CFS/ME patients, dysfunctional MAPK signalling may contribute to reduced NK cell cytotoxic activity.

Source: Huth TK, Staines D, Marshall-Gradisnik S. ERK1/2, MEK1/2 and p38 downstream signalling molecules impaired in CD56 dim CD16+ and CD56 bright CD16 dim/- natural killer cells in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis patients. J Transl Med. 2016 Apr 21;14:97. doi: 10.1186/s12967-016-0859-z. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4839077/ (Full article)

Regulatory T, natural killer T and γδ T cells in multiple sclerosis and chronic fatigue syndrome/myalgic encephalomyelitis: a comparison

Abstract:

BACKGROUND: Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME), and Multiple Sclerosis (MS) may share some similarities in relation to reduced NK cell activity. It is likely that other cells such as regulatory T (Tregs), invariant Natural Killer T (iNKT) and gamma delta T (γδ T) cells may also be dysregulated in CFS/ME and MS.

OBJECTIVE: To evaluate and compare specific immune regulatory cells of patients with CFS/ME, patients with MS and healthy controls.

METHOD: Sixty three volunteers were included in this study: 24 were CFS/ME patients, 11 were MS patients and 27 were healthy controls. Blood samples were obtained from all participants for flow cytometry analysis of iNKT cells, Tregs and γδ T cell phenotypes.

RESULTS: We observed a significant increase in Tregs in the CFS/ME group (p≤0.05) compared to the healthy control group. Total γδ and γδ2 T cells were significantly reduced in MS patients in comparison with the healthy control group. Conversely, CD4+iNKT percentage of iNKT, was significantly increased in the CFS/ME group compared with healthy controls and the double-negative iNKT percentage of iNKT significantly decreased compared with the healthy control group.

CONCLUSIONS: This study has not identified any immunological disturbances that are common in both MS and CFS/ME patients. However, the differential expression of cell types between the conditions investigated suggests different pathways of disease. These differences need to be explored in further studies.

Source: Ramos S, Brenu E, Broadley S, Kwiatek R, Ng J, Nguyen T, Freeman S, Staines D, Marshall-Gradisnik S. Regulatory T, natural killer T and γδ T cells in multiple sclerosis and chronic fatigue syndrome/myalgic encephalomyelitis: a comparison. Asian Pac J Allergy Immunol. 2016 Dec;34(4):300-305. doi: 10.12932/AP0733. http://apjai-journal.org/wp-content/uploads/2016/12/8RegulatoryTnaturalkillerAPJAIVol34No4December2016P300.pdf (Full text as PDF)

Pilot Study of Natural Killer Cells in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis and Multiple Sclerosis

Abstract:

Patients with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) and multiple sclerosis (MS) suffer from debilitating fatigue which is not alleviated by rest. In addition to the fatigue-related symptoms suffered by patients with CFS/ME and MS, dysfunction of the immune system and, in particular, reduced natural killer (NK) cell cytotoxic activity has also been reported in CFS/ME and MS. The purpose of this pilot study was to compare NK cellular mechanisms in patients with CFS/ME and MS to investigate potential dysfunctions in the NK cell activity pathway. Flow cytometry protocols assessed CD56(dim) CD16(+) and CD56(bright) CD16(+/-) NK cell expression of adhesion molecules, NK activating and inhibiting receptors, NK cell maturation and lytic proteins.

All participants in this study were female and included 14 patients with CFS/ME, nine patients with MS and 19 non-fatigued controls. The patient groups and the non-fatigued controls were not taking any immunosuppressive or immune-enhancing medications. In the MS cohort, KIR2DL5 was significantly increased on CD56(bright) CD16(+/-) NK cells and expression of CD94 was significantly increased on CD56(dim) CD16(+) NK cells in comparison with the controls. Co-expression of CD57 and perforin was significantly increased on CD56(dim) CD16(+) NK cells from patients with CFS/ME compared to the MS and non-fatigued control participants.

The results from this pilot study suggest that NK cells from patients with CFS/ME and MS may have undergone increased differentiation in response to external stimuli which may affect different mechanisms in the NK cell cytotoxic activity pathway.

Source: Huth TK, Brenu EW, Ramos S, Nguyen T, Broadley S, Staines D, Marshall-Gradisnik S. Pilot Study of Natural Killer Cells in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis and Multiple Sclerosis. Scand J Immunol. 2016 Jan;83(1):44-51. doi: 10.1111/sji.12388. http://onlinelibrary.wiley.com/wol1/doi/10.1111/sji.12388/full (Full article)

Natural killer cells in patients with severe chronic fatigue syndrome

Abstract:

Maintenance of health and physiological homeostasis is a synergistic process involving tight regulation of proteins, transcription factors and other molecular processes. The immune system consists of innate and adaptive immune cells that are required to sustain immunity. The presence of pathogens and tumour cells activates innate immune cells, in particular Natural Killer (NK) cells.

Stochastic expression of NK receptors activates either inhibitory or activating signals and results in cytokine production and activation of pathways that result in apoptosis of target cells. Thus, NK cells are a necessary component of the immunological process and aberrations in their functional processes, including equivocal levels of NK cells and cytotoxic activity pre-empts recurrent viral infections, autoimmune diseases and altered inflammatory responses. NK cells are implicated in a number of diseases including chronic fatigue syndrome (CFS). The purpose of this review is to highlight the different profiles of NK cells reported in CFS patients and to determine the extent of NK immune dysfunction in subtypes of CFS patients based on severity in symptoms.

Source: Brenu EW, Hardcastle SL, Atkinson GM, van Driel ML, Kreijkamp-Kaspers S, Ashton KJ, Staines DR, Marshall-Gradisnik SM. Natural killer cells in patients with severe chronic fatigue syndrome. Auto Immun Highlights. 2013 Apr 16;4(3):69-80. doi: 10.1007/s13317-013-0051-x. ECollection 2013. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4389023/ (Full article)

Immunophenotyping in post-giardiasis functional gastrointestinal disease and chronic fatigue syndrome

Abstract:

BACKGROUND: A Giardia outbreak was associated with development of post-infectious functional gastrointestinal disorders (PI-FGID) and chronic fatigue syndrome (PI-CFS). Markers of immune dysfunction have given conflicting results in CFS and FGID patient populations. The aim of this study was to evaluate a wide selection of markers of immune dysfunction in these two co-occurring post-infectious syndromes.

METHODS: 48 patients, reporting chronic fatigue in a questionnaire study, were clinically evaluated five years after the outbreak and grouped according to Fukuda criteria for CFS (n=19) and idiopathic chronic fatigue (n=5) and Rome II criteria for FGIDs (n=54). 22 Giardia exposed non-fatigued individuals and 10 healthy unexposed individuals were recruited as controls. Peripheral blood lymphocyte subsets were analyzed by flow cytometry.

RESULTS: In peripheral blood we found significantly higher CD8 T-cell levels in PI-FGID, and significantly lower NK-cell levels in PI-CFS patients. Severity of abdominal and fatigue symptoms correlated negatively with NK-cell levels. A tendency towards lower T-cell CD26 expression in FGID was seen.

CONCLUSION: Patients with PI-CFS and/or PI-FGID 5 years after Giardia lamblia infection showed alterations in NK-cell and CD8-cell populations suggesting a possible immunological abnormality in these conditions. We found no significant changes in other markers examined in this well-defined group of PI-CFS and PI-FGID elicited by a gastrointestinal infection. Controlling for co-morbid conditions is important in evaluation of CFS-biomarkers.

Source: Hanevik K, Kristoffersen EK, Sørnes S, Mørch K, Næss H, Rivenes AC, Bødtker JE, Hausken T, Langeland N. Immunophenotyping in post-giardiasis functional gastrointestinal disease and chronic fatigue syndrome. BMC Infect Dis. 2012 Oct 14;12:258. doi: 10.1186/1471-2334-12-258. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3553045/ (Full article)

Decreased expression of CD69 in chronic fatigue syndrome in relation to inflammatory markers: evidence for a severe disorder in the early activation of T lymphocytes and natural killer cells

Abstract:

There is some evidence that patients with chronic fatigue syndrome (CFS) suffer from immune abnormalities, such as immune activation and decreased immune cell responsivity upon polyclonal stimili. This study was designed to evaluate lymphocyte activation in CFS by using a CD69 expression assay. CD69 acts as a costimulatory molecule for T- and natural killer (NK) cell activation.

We collected whole blood from CFS patients, who met CDC criteria, and healthy volunteers. The blood samples were stimulated with mitogens during 18 h and the levels of activated T and NK cells expressing CD69 were measured on a Coulter Epics flow cytometer using a three color immunofluorescence staining protocol.

The expression of the CD69 activation marker on T cells (CD3+, CD3+CD4+, and CD3+CD8+) and on NK cells (CD45+CD56+) was significantly lower in CFS patients than in healthy subjects. These differences were significant to the extent that a significant diagnostic performance was obtained, i.e. the area under the ROC curve was around 89%. No differences either in the number of leukocytes or in the number or percentage of lymphocytes, i.e. CD3, CD4, CD8 and CD19, could be found between CFS patients and the controls.

Patients with CFS show defects in T- and NK cell activation. Since induction of CD69 surface expression is dependent on the activation of the protein kinase C (PKC) activation pathway, it is suggested that in CFS there is a disorder in the early activation of the immune system involving PKC.

Source: Mihaylova I, DeRuyter M, Rummens JL, Bosmans E, Maes M. Decreased expression of CD69 in chronic fatigue syndrome in relation to inflammatory markers: evidence for a severe disorder in the early activation of T lymphocytes and natural killer cells. Neuro Endocrinol Lett. 2007 Aug;28(4):477-83. https://www.ncbi.nlm.nih.gov/pubmed/17693977

A placebo-controlled, double-blind, randomized controlled trial of a natural killer cell stimulant (BioBran MGN-3) in chronic fatigue syndrome

Abstract:

BACKGROUND: Previous research has suggested that natural killer (NK) cell activity may be reduced in patients with chronic fatigue syndrome (CFS).

AIM: To evaluate the effectiveness of a putative NK cell stimulant, BioBran MGN-3, in reducing fatigue in CFS patients.

DESIGN: Randomized, double-blind, placebo-controlled trial.

METHODS: We recruited 71 patients with CFS (according to the Centers for Disease Control 1994 criteria) attending an out-patient specialist CFS service. Participants were given oral BioBran MGN-3 for 8 weeks (2 g three times per day) or placebo equivalent. The primary outcome measure was the Chalder physical fatigue score. Self-reported fatigue measures, self-assessment of improvement, change in key symptoms, quality of life, anxiety and depression measures were also included.

RESULTS: Data were complete in 64/71 patients. Both groups showed marked improvement over the study duration, but without significant differences. Mean improvement in the Chalder fatigue score (physical scale) was 0.3 (95%CI -2.6 to 3.2) lower in the BioBran group.

DISCUSSION: The findings do not support a specific therapeutic effect for BioBran in CFS. The improvement showed by both groups over time highlights the importance of placebo controls when evaluating interventions in CFS.

Source: McDermott C, Richards SC, Thomas PW, Montgomery J, Lewith G. A placebo-controlled, double-blind, randomized controlled trial of a natural killer cell stimulant (BioBran MGN-3) in chronic fatigue syndrome. QJM. 2006 Jul;99(7):461-8. Epub 2006 Jun 29. http://qjmed.oxfordjournals.org/content/99/7/461.long (Full article)

Chronic fatigue syndrome following a toxic exposure

Abstract:

Chronic fatigue syndrome (CFS) is a clinical entity characterized by severe fatigue lasting more than 6 months and other well-defined symptoms. Even though in most CFS cases the etiology is still unknown, sometimes the mode of presentation of the illness implicates the exposure to chemical and/or food toxins as precipitating factors: ciguatera poisoning, sick building syndrome, Gulf War syndrome, exposure to organochlorine pesticides, etc.

In the National Reference Center for CFS Study at the Department of Infectious Diseases of ‘G. D’Annunzio’ University (Chieti) we examined five patients (three females and two males, mean age: 37.5 years) who developed the clinical features of CFS several months after the exposure to environmental toxic factors: ciguatera poisoning in two cases, and exposure to solvents in the other three cases. These patients were compared and contrasted with two sex- and age-matched subgroups of CFS patients without any history of exposure to toxins: the first subgroup consisted of patients with CFS onset following an EBV infection (post-infectious CFS), and the second of patients with a concurrent diagnosis of major depression.

All subjects were investigated by clinical examination, neurophysiological and immunologic studies, and neuroendocrine tests. Patients exposed to toxic factors had disturbances of hypothalamic function similar to those in controls and, above all, showed more severe dysfunction of the immune system with an abnormal CD4/CD8 ratio, and in three of such cases with decreased levels of NK cells (CD56+). These findings may help in understanding the pathogenetic mechanisms involved in CFS.

Source: Racciatti D, Vecchiet J, Ceccomancini A, Ricci F, Pizzigallo E. Chronic fatigue syndrome following a toxic exposure. Sci Total Environ. 2001 Apr 10;270(1-3):27-31. http://www.ncbi.nlm.nih.gov/pubmed/11327394

Changes in immune parameters seen in Gulf War veterans but not in civilians with chronic fatigue syndrome

Abstract:

The purpose of this study was to evaluate immune function through the assessment of lymphocyte subpopulations (total T cells, major histocompatibility complex [MHC] I- and II-restricted T cells, B cells, NK cells, MHC II-restricted T-cell-derived naive and memory cells, and several MHC I-restricted T-cell activation markers) and the measurement of cytokine gene expression (interleukin 2 [IL-2], IL-4, IL-6, IL-10, IL-12, gamma interferon [IFN-gamma], and tumor necrosis factor alpha [TNF-alpha]) from peripheral blood lymphocytes.

Subjects included two groups of patients meeting published case definitions for chronic fatigue syndrome (CFS)-a group of veterans who developed their illness following their return home from participating in the Gulf War and a group of nonveterans who developed the illness sporadically. Case control comparison groups were comprised of healthy Gulf War veterans and nonveterans, respectively.

We found no significant difference for any of the immune variables in the nonveteran population. In contrast, veterans with CFS had significantly more total T cells and MHC II+ T cells and a significantly higher percentage of these lymphocyte subpopulations, as well as a significantly lower percentage of NK cells, than the respective controls.

In addition, veterans with CFS had significantly higher levels of IL-2, IL-10, IFN-gamma, and TNF-alpha than the controls. These data do not support the hypothesis of immune dysfunction in the genesis of CFS for sporadic cases of CFS but do suggest that service in the Persian Gulf is associated with an altered immune status in veterans who returned with severe fatiguing illness.

Source: Zhang Q, Zhou XD, Denny T, Ottenweller JE, Lange G, LaManca JJ, Lavietes MH, Pollet C, Gause WC, Natelson BH. Changes in immune parameters seen in Gulf War veterans but not in civilians with chronic fatigue syndrome. Clin Diagn Lab Immunol. 1999 Jan;6(1):6-13. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC95652/ (Full article)

Clinical improvement in chronic fatigue syndrome is not associated with lymphocyte subsets of function or activation

Abstract:

The relationship between markers of immune function and chronic fatigue syndrome (CFS) is controversial. To examine the relationship directly, 43 subjects with CFS entering a randomized controlled trial of a nonpharmacological treatment for CFS gave samples for immunological analysis before and after treatment. Percentage levels of total CD3+ T cells, CD4 T cells, CD8 T cells, and activated subsets did not differ between CFS subjects and controls. Naive (CD45RA+ RO-) and memory (CD45RA- RO+) T cells did not differ between subjects and controls.

Natural killer cells (CD16+/CD56+/CD3-) were significantly increased in CFS patients compared to controls, as was the percentage of CD11b+ CD8 cells.

There were no correlations between any immune variable and measures of clinical status, with the exception of a weak correlation between total CD4 T cells and fatigue. There was a positive correlation between memory CD4 and CD8 T cells and depression scores and a negative correlation between naive CD4 T cells and depression.

No immune measures changed during the course of the study, and there was no link between clinical improvement as a result of the treatment program and immune status. Immune measures did not predict response or lack of response to treatment.

In conclusion, we have been unable to replicate previous findings of immune activation in CFS and unable to find any important associations between clinical status, treatment response, and immunological status.

Source: Peakman M, Deale A, Field R, Mahalingam M, Wessely S. Clinical improvement in chronic fatigue syndrome is not associated with lymphocyte subsets of function or activation. Clin Immunol Immunopathol. 1997 Jan;82(1):83-91. http://www.ncbi.nlm.nih.gov/pubmed/9000046