Decreased non-MHC-restricted (CD56+) killer cell cytotoxicity after spaceflight

2001 ◽  
Vol 91 (4) ◽  
pp. 1814-1818 ◽  
Author(s):  
Satish K. Mehta ◽  
Indreshpal Kaur ◽  
Elizabeth A. Grimm ◽  
Christine Smid ◽  
Daniel L. Feeback ◽  
...  

Cytotoxic activity of non-major histocompatibility complex-restricted (CD56+) (NMHC) killer cells and cell surface marker expression of peripheral blood mononuclear cells were determined before and after spaceflight. Ten astronauts (9 men, 1 woman) from two space shuttle missions (9- and 10-day duration) participated in the study. Blood samples were collected 10 days before launch, within 3 h after landing, and 3 days after landing. All peripheral blood mononuclear cell preparations were cryopreserved and analyzed simultaneously in a 4-h cytotoxicity51Cr release assay using K562 target cells. NMHC killer cell lytic activity was normalized per 1,000 CD56+cells. When all 10 subjects were considered as one study group, NMHC killer cell numbers did not change significantly during the three sampling periods, but at landing lytic activity had decreased by ∼40% ( P < 0.05) from preflight values. Nine of ten astronauts had decreased lytic activity immediately after flight. NMHC killer cell cytotoxicity of only three astronauts returned toward preflight values by 3 days after landing. Consistent with decreased NMHC killer cell cytotoxicity, urinary cortisol significantly increased after landing compared with preflight levels. Plasma cortisol and ACTH levels at landing were not significantly different from preflight values. No correlation of changes in NMHC killer cell function or hormone levels with factors such as age, gender, mission, or spaceflight experience was found. After landing, expression of the major lymphocyte surface markers (CD3, CD4, CD8, CD14, CD16, CD56), as determined by flow cytometric analysis, did not show any consistent changes from measurements made before flight.

2020 ◽  
Author(s):  
Lina Schiffer ◽  
Alicia Bossey ◽  
Angela E Taylor ◽  
Ildem Akerman ◽  
Dagmar Scheel-Toellner ◽  
...  

AbstractContextAndrogens are important modulators of immune cell function impacting proliferation, differentiation and cytokine production. The local generation of active androgens from circulating androgen precursors is an important mediator of androgen action in peripheral androgen target cells or tissue.ObjectiveTo characterize the activation of classic and 11-oxygenated androgens in human peripheral blood mononuclear cells (PBMCs).MethodsPBMCs were isolated from healthy male donors and incubated ex vivo with precursors and active androgens of the classic and 11-oxygenated androgen pathways. Steroids were quantified by liquid chromatography-tandem mass spectrometry. The expression of genes encoding steroid-metabolizing enzymes was assessed by quantitative PCR.ResultsPBMCs generated 8-fold higher amounts of the active 11-oxygenated androgen 11-ketotestosterone than the classic androgen testosterone from their respective precursors. We identified the enzyme AKR1C3 as the major reductive 17β-hydroxysteroid dehydrogenase in PBMCs responsible for both conversions and found that within the PBMC compartment natural killer cells are the major site of AKRC13 expression and activity. Steroid 5α-reductase type 1 catalyzed the 5α-reduction of classic but not 11-oxygenated androgens in PBMCs. Lag time prior to the separation of cellular components from whole blood increased 11KT serum concentrations in a time-dependent fashion, with significant increases detected from two hours after blood collection.Conclusions11-oxygenated androgens are the preferred substrates for androgen activation by AKR1C3 in PBMCs, primarily conveyed by natural killer cell AKR1C3 activity, yielding 11KT the major active androgen in PBMCs. Androgen metabolism by PBMCs can affect the measurement results of serum 11-ketotestosterone concentrations, if samples are not separated in a timely fashion.


2019 ◽  
Author(s):  
Tao Huang ◽  
Jun Zhang ◽  
Wujian Ke ◽  
Xiaohui Zhang ◽  
Wentao Chen ◽  
...  

Abstract Background Treponema pallidum ( T. pallidum ) infection evokes significant immune responses, resulting in tissue damage. The immune mechanism underlying T. pallidum infection is still unclear, although microRNAs (miRNAs) have been shown to influence immune cell function and, consequently, the generation of antibody responses during other microbe infections. However, these mechanisms are unknown for T. pallidum . Methods In this study, we performed a comprehensive analysis of differentially expressed miRNAs in healthy individuals, untreated patients with syphilis, patients in the serofast state, and serologically cured patients. miRNAs were profiled from the peripheral blood of patients obtained at the time of serological diagnosis. Then, both the target sequence analysis of these different miRNAs and pathway analysis were performed to identify important immune and cell signaling pathways. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was performed for microRNA analysis. Results A total of 89 differentially regulated miRNAs were identified. Following RT-qPCR confirmation, three miRNAs (hsa-miR-195-5p, hsa-miR-223-3p, hsa-miR-589-3p) showed significant differences in the serofast and serologically cured states ( P <0.05). One miRNA (hsa-miR-195-5p) showed significant differences between untreated patients and healthy individuals. Conclusions This is the first study of miRNA expression differences in peripheral blood mononuclear cells (PBMCs) in different stages of T. pallium infection. Our study suggests that the combination of three miRNAs has great potential to serve as a non-invasive biomarker of T. pallium infections, which will facilitate better diagnosis and treatment of T. pallium infections.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4879-4879
Author(s):  
Juan Tong ◽  
Huilan Liu ◽  
Liangquan Geng ◽  
Zimin Sun ◽  
Baolin Tang ◽  
...  

Abstract Natural killer (NK) cell alloreactivity is reported to mediate strong graft versus leukemia (GVL) effect in patients after allogeneic stem-cell transplantation. NKG2D receptors recognize human MHC class Ichain related A and B (MICA/B) and UL16-binding protein 1∼4(ULBP 1∼4) on target cells, thereby regulating NK cell activity. To examine the recovery of NKG2D, NKG2A and other receptors expression by NK cells, we used flow cytometry to evaluate samples from 11 chronic myeloid leukemia patients and their donors in the year following unmanipulated HLA completely matched peripheral blood stem cells plus bone marrow transplantation. Peripheral blood mononuclear cells from patients and their donors were tested in standard 51Cr release assays against cultured K562 targets to determine the cytotoxicity of the NK cells in the same intervals. There is no mismatched immunoglobulin-like receptor (KIR) ligand in both GVH and HVG direction. The reconstitution of KIR2DL1 (CD158a) after this transplantation protocol was very slow and these receptors didn’t reach normal value in the year and KIR2DL2 (CD158b) was much better. The NKG2D increased and the NKG2A decreased quickly at the same time after engraftment, and used linear regression analysis we demonstrated that NKG2A recovery was inversely correlated with NKG2D recovery in the year following transplantation. The ratio of NKG2D/NKG2A was directly associated with the capacity of NK-cell cytotoxicity. Thus, the reconstitution of NKG2D makes contribution to the recovery of the NK cytotoxicity. These results reveals that the NK cells generated after HLA matched blood plus bone morrow transplantation of CML patients are promoted at an immature state characterized by specific phenotypic features and enhanced functioning, having potential impact for immune responsiveness and transplantation outcome.


2003 ◽  
Vol 5 (2) ◽  
pp. 142-152 ◽  
Author(s):  
Sandra Adams Motzer ◽  
Joyce Tsuji ◽  
Vicky Hertig ◽  
Sandra K. Johnston ◽  
James Scanlan

The purpose of this study is to describe design considerations for the use of flow cytometry (FC) com-pared to51chromium (51Cr)-release assays utilizing cryopreserved peripheral blood mononuclear cells (PBMCs) to detect natural killer (NK) cell cytotoxicity. Subjects were 10 healthy women aged 18 to 39 years. Intra-assay variability between methods differed only at the lowest effector-target ratios evaluated. Interassay variability was wide but did not differ between methods. The relationship of lytic unit-10 between methods was strongly positive. Cytotoxicity detected by51Cr release was higher than that detected by FC for all 10 subjects. Cost was comparable. How-ever, had more assays been performed, technician time would have been greater with flow cytometry. More whole blood was needed to perform the flow cytometry cytotoxicity assay than51Cr-release cytotoxicity assay. The authors found no compelling reason to adopt NK cell cytotoxicity by flow cytometry over51Cr release.


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