Tag: CD38

In vitro B cell experiments explore the role of CD24, CD38 and energy metabolism in ME/CFS

Abstract:

Disturbances of energy metabolism contribute to clinical manifestations of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Previously we found that B cells from ME/CFS patients have increased expression of CD24, a modulator of many cellular functions including those of cell stress.

The relative ability of B cells from ME/CFS patients and healthy controls (HC) to respond to rapid changes in energy demand were compared. CD24, the ectonucleotidases CD39, CD73, the NAD-degrading enzyme CD38 and mitochondrial mass (MM) were measured following cross-linking of the B cell receptor (BCR) and co-stimulation with either T cell dependent or Toll-like receptor-9 dependent agonists. Levels of metabolites consumed/produced were measured using 1H-NMR spectroscopy and analysed in relation to cell growth and immunophenotype.

Proliferating B cells from patients with ME/CFS showed lower mitochondrial mass and a significantly increased usage of essential amino acids compared those from HC, with a significantly delayed loss of CD24 and increased expression of CD38 following stimulation. Immunophenotype results suggested the triggering of a stress response in ME/CFS B cells associated with increased usage of additional substrates to maintain necessary ATP levels. Disturbances in energy metabolism in ME/CFS B cells were thus confirmed in a dynamic in vitro model, providing the basis for further mechanistic investigations.

Source: Christopher Armstrong, Fane F. Mensah, Maria Leandro, Venkat Reddy, Paul R. Gooley, Saul Berkovitz, Geraldine Cambridge. In vitro B cell experiments explore the role of CD24, CD38 and energy metabolism in ME/CFS. Front. Immunol. Sec. B Cell Biology, Volume 14 – 2023 | doi: 10.3389/fimmu.2023.1178882 https://www.frontiersin.org/articles/10.3389/fimmu.2023.1178882/abstract

Transient receptor potential melastatin 2 channels are overexpressed in myalgic encephalomyelitis/chronic fatigue syndrome patients

Abstract:

BACKGROUND: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is hallmarked by a significant reduction in natural killer (NK) cell cytotoxicity, a mechanism tightly regulated by calcium (Ca2+). Interestingly, interleukin-2 (IL-2) increases NK cell cytotoxicity. Transient receptor potential melastatin 2 (TRPM2) ion channels are fundamental for Ca2+ signalling in NK cells. This pilot investigation aimed to characterise TRPM2 and CD38 surface expression in vitro on NK cells in ME/CFS patients. This investigation furthermore examined the pharmaceutical effect of 8-bromoadenosine phosphoribose (8-Br-ADPR) and N6-Benzoyladenosine-3′,5′-cyclic monophosphate (N6-Bnz-cAMP) on TRPM2 and CD38 surface expression and NK cell cytotoxicity between ME/CFS and healthy control (HC) participants.

METHODS: Ten ME/CFS patients (43.45 ± 12.36) and 10 HCs (43 ± 12.27) were age and sex-matched. Isolated NK cells were labelled with fluorescent antibodies to determine baseline and drug-treated TRPM2 and CD38 surface expression on NK cell subsets. Following IL-2 stimulation, NK cell cytotoxicity was measured following 8-Br-ADPR and N6-Bnz-cAMP drug treatments by flow cytometry.

RESULTS: Baseline TRPM2 and CD38 surface expression was significantly higher on NK cell subsets in ME/CFS patients compared with HCs. Post IL-2 stimulation, TRPM2 and CD38 surface expression solely decreased on the CD56DimCD16+ subset. 8-Br-ADPR treatment significantly reduced TRPM2 surface expression on the CD56BrightCD16Dim/- subset within the ME/CFS group. Baseline cell cytotoxicity was significantly reduced in ME/CFS patients, however no changes were observed post drug treatment in either group.

CONCLUSION: Overexpression of TRPM2 on NK cells may function as a compensatory mechanism to alert a dysregulation in Ca2+ homeostasis to enhance NK cell function in ME/CFS, such as NK cell cytotoxicity. As no improvement in NK cell cytotoxicity was observed within the ME/CFS group, an impairment in the TRPM2 ion channel may be present in ME/CFS patients, resulting in alterations in [Ca2+]i mobilisation and influx, which is fundamental in driving NK cell cytotoxicity. Differential expression of TRPM2 between NK cell subtypes may provide evidence for their role in the pathomechanism involving NK cell cytotoxicity activity in ME/CFS.

Source: Balinas C, Cabanas H, Staines D, Marshall-Gradisnik S. Transient receptor potential melastatin 2 channels are overexpressed in myalgic encephalomyelitis/chronic fatigue syndrome patients. J Transl Med. 2019 Dec 3;17(1):401. doi: 10.1186/s12967-019-02155-4. https://www.ncbi.nlm.nih.gov/pubmed/31796045

Lymphocyte subsets, apoptosis, and cytokines in patients with chronic fatigue syndrome

Abstract:

Whether immunologic abnormalities correlate with fatigue severity and functional impairment in chronic fatigue syndrome (CFS) was investigated. Blood mononuclear cells were immunophenotyped and circulating ex vivo-produced cytokines were measured in 76 CFS patients and 69 healthy matched controls. Expression of CD11b on CD8 cells was significantly decreased in CFS patients. However, the previously reported increased expression of CD38 and HLA-DR was not confirmed. There was no obvious difference in apoptosis in leukocyte cultures, circulating cytokines, and ex vivo production of interleukin (IL)-1 alpha and IL-1 receptor antagonist. Endotoxin-stimulated ex vivo production of tumor necrosis factor-alpha and IL-beta was significantly lower in CFS. The immunologic test results did not correlate with fatigue severity or psychologic well-being was measured by Checklist Individual Strength, Beck Depression Inventory, and Sickness Impact Profile. Thus, these immunologic tests cannot be used as diagnostic tools in individual CFS patients.

 

Source: Swanink CM, Vercoulen JH, Galama JM, Roos MT, Meyaard L, van der Ven-Jongekrijg J, de Nijs R, Bleijenberg G, Fennis JF, Miedema F, van der Meer JW. Lymphocyte subsets, apoptosis, and cytokines in patients with chronic fatigue syndrome. J Infect Dis. 1996 Feb;173(2):460-3. http://jid.oxfordjournals.org/content/173/2/460.long (Full article)

 

Chronic fatigue syndrome. Immunological findings vary between populations

Comment on: Longitudinal study of outcome of chronic fatigue syndrome. [BMJ. 1994]

 

Editor,-We were interested in Andrew Wilson and colleagues’ paper investigating predictors of the long term outcome of the chronic fatigue syndrome in patients in Australia. We have investigated the association between immune activation and presumed cutaneous anergy in 68 Scottish patients with the syndrome (19 cases conformed to the Centers for Disease Control’s criteria, 18 cases had been diagnosed by a consultant, 28 cases had been diagnosed by a general practitioner, and three patients referred themselves) and 22 family contacts. We assessed delayed hypersensitivity responses (using Multitest antigens and tuberculin skin tests) and evaluated peripheral blood activation markers (CD8, CD38/ CD llb/HLA-DR) using flow cytometry. Patients were classified into three groups on the basis of current severity of illness and mobility.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540184/pdf/bmj00440-0055b.pdf

 

Source: Abbot NC, Spence VA, Lowe JG, Potts RC, Hassan AH, Belch JJ, Beck JS. Chronic fatigue syndrome. Immunological findings vary between populations. BMJ. 1994 May 14;308(6939):1299. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540184/

 

Immunologic abnormalities associated with chronic fatigue syndrome

Abstract:

Several aspects of cellular immunity in patients with clinically defined chronic fatigue syndrome (CFS) were evaluated and compared with those in healthy individuals.

Flow cytometric analyses revealed normal expression of total T (CD3+), B (CD19+), and NK (natural killer) (CD16+, CD56+) markers on the surface of peripheral blood mononuclear cells (PMC) from patients with CFS.

However, compared with those of healthy individuals, patients’ CD8+ T cells expressed reduced levels of CD11b and expressed the activation markers CD38 and HLA-DR at elevated levels. In many of the individuals in whom expression of CD11b was reduced the expression of CD28 was increased.

These findings indicate expansion of a population of activated CD8+ cytotoxic T lymphocytes. A marked decrease in NK cell activity was found in almost all patients with CFS, as compared with that in healthy individuals. No substantial abnormalities in monocyte activity or T cell proliferation were observed. The results of this study suggest that immune cell phenotype changes and NK cell dysfunction are common manifestations of CFS.

 

Source: Barker E, Fujimura SF, Fadem MB, Landay AL, Levy JA. Immunologic abnormalities associated with chronic fatigue syndrome. Clin Infect Dis. 1994 Jan;18 Suppl 1:S136-41. http://www.ncbi.nlm.nih.gov/pubmed/8148441

 

Chronic fatigue syndrome: clinical condition associated with immune activation

Abstract:

There is much conflicting immunological and viral data about the causes of chronic fatigue syndrome (CFS); some findings support the notion that CFS may be due to one or more immune disorders that have resulted from exposure to an infectious agent.

In the present study, flow cytometry and several different recognising T, B, and natural killer (NK) cell populations as well as activation and cell adhesion antigens were used to study 147 individuals with CFS.

Compared with healthy controls, a reduced CD8 suppressor cell population and increased activation markers (CD38, HLA-DR) on CD8 cells were found. The differences were significant (p = 0.01) in patient with major symptoms of the disease. These immunological indices were not observed in 80 healthy individuals, in 22 contacts of CFS patients, or in 43 patients with other diseases.

No correlation of these findings in CFS patients with any known human viruses could be detected by serology. The findings suggest that immune activation is associated with many cases of CFS.

 

Source: Landay AL, Jessop C, Lennette ET, Levy JA. Chronic fatigue syndrome: clinical condition associated with . Lancet. 1991 Sep 21;338(8769):707-12. http://www.ncbi.nlm.nih.gov/pubmed/1679864