scholarly journals Control of hsp70 RNA levels in human lymphocytes.

1987 ◽  
Vol 104 (2) ◽  
pp. 183-187 ◽  
Author(s):  
L Kaczmarek ◽  
B Calabretta ◽  
H T Kao ◽  
N Heintz ◽  
J Nevins ◽  
...  
Keyword(s):  
Culture Medium ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Peripheral Blood Mononuclear ◽  
Growth State ◽  
Steady State Levels ◽  
Rna Blots

The expression of a hsp70 gene in human cells has previously been shown to be related to the growth state of the cells. As an alternative to in vitro synchronization procedures, we have measured steady-state levels of the RNA for a heat-shock protein 70 (hsp70) in human peripheral blood mononuclear cells (PBMC) that are naturally quiescent in a G0 state. The probe used recognized, on RNA blots, one single band. The levels of this hsp70 RNA are elevated in circulating PBMC and decrease when the cells are incubated with serum, or phytohemagglutinin, or simply when they are incubated in culture medium. The levels of hsp70 RNA decrease within 30 min after in vitro culture, and are accompanied by an increase in the levels of c-fos RNA. These findings, together with other recent reports in the literature, suggest a possible role of the hsp70 proteins in the regulation of cell growth.

High levels of thyroid hormone impair regulatory T cells function via reduced PD-1 expression

2021 ◽  
Author(s):  
Yi Zhong ◽  
Ting-Ting Lu ◽  
Xiao-Mei Liu ◽  
Bing-Li Liu ◽  
Yun Hu ◽  
...  
Keyword(s):  
T Cells ◽  
Thyroid Hormone ◽  
Regulatory T Cells ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Dependent Manner ◽  
Peripheral Blood Mononuclear

Abstract Context Regulatory T cells (Tregs) dysfunction plays an important role in the development and progression of Graves’ disease (GD). Programmed cell death 1 (PD-1) prompts FoxP3 in Tregs expression and enhances the suppressive activity of Tregs. Whether abnormal expression of PD-1 contributes to the breakdown of Tregs and the role of thyroid hormone in the PD-1 expression of Tregs in GD remain substantially undefined. Objective To evaluate the role of PD-1 in Tregs function and triiodothyronine (T3) in PD-1 expression in patients with GD and mice treated with T3. Methods We recruited 30 patients with GD and 30 healthy donors. PD-1 expression in Tregs and Tregs function were determined. To evaluate the effects of thyroid hormone on PD-1 expression in Tregs, we used T3 for the treatment of human peripheral blood mononuclear cells (PBMCs). We then treated mice with T3 to confirm the effect of thyroid hormone on PD-1 expression in Tregs and Tregs function in vivo. Results PD-1 expression in Tregs and the suppressive function of Tregs significantly decreased in patients with GD. T3 reduced PD-1 expression in human Tregs in a concentration- and time-dependent manner in vitro. High levels of circulating T3 reduced PD-1 expression in Tregs, impaired Tregs function, and disrupted T-helper cell (Th1 and Th2) balance in mice treated with T3. Conclusions Tregs dysfunction in GD patients might be due to down-regulation of PD-1 expression in Tregs induced by high levels of serum T3.

scholarly journals Infection of human lymphomononuclear cells by SARS-CoV-2

2020 ◽  
Author(s):  
Marjorie C Pontelli ◽  
Italo A Castro ◽  
Ronaldo B Martins ◽  
Flávio P Veras ◽  
Leonardo La Serra ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Severe Infection ◽  
Peripheral Blood Mononuclear ◽  
Healthy Donors ◽  
B And T Lymphocytes

AbstractAlthough SARS-CoV-2 severe infection is associated with a hyperinflammatory state, lymphopenia is an immunological hallmark, and correlates with poor prognosis in COVID-19. However, it remains unknown if circulating human lymphocytes and monocytes are susceptible to SARS-CoV-2 infection. In this study, SARS-CoV-2 infection of human peripheral blood mononuclear cells (PBMCs) was investigated both in vitro and in vivo. We found that in vitro infection of whole PBMCs from healthy donors was productive of virus progeny. Results revealed that monocytes, as well as B and T lymphocytes, are susceptible to SARS-CoV-2 active infection and viral replication was indicated by detection of double-stranded RNA. Moreover, flow cytometry and immunofluorescence analysis revealed that SARS-CoV-2 was frequently detected in monocytes and B lymphocytes from COVID-19 patients, and less frequently in CD4+T lymphocytes. The rates of SARS-CoV-2-infected monocytes in PBMCs from COVID-19 patients increased over time from symptom onset. Additionally, SARS-CoV-2-positive monocytes and B and CD4+T lymphocytes were detected by immunohistochemistry in post mortem lung tissue. SARS-CoV-2 infection of blood circulating leukocytes in COVID-19 patients may have important implications for disease pathogenesis, immune dysfunction, and virus spread within the host.

scholarly journals Replication of measles virus in human lymphocytes.

1985 ◽  
Vol 161 (6) ◽  
pp. 1261-1271 ◽  
Author(s):  
T Hyypiä ◽  
P Korkiamäki ◽  
R Vainionpää
Keyword(s):  
Measles Virus ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Viral Rna ◽  
T Cell Subsets ◽  
Productive Infection ◽  
Peripheral Blood Mononuclear ◽  
Hemagglutinin Protein

Replication of measles virus was restricted in human peripheral blood mononuclear cells (PBMC). However, in in vitro-infected, unstimulated cells, active synthesis of viral RNA and proteins occurred, while the release of infectious virus could not be detected. Stimulation with PHA caused a productive infection cycle comparable to the lytic infection. Replication of viral RNA was demonstrated in both T and B cells, and in both OKT4+- and OKT8+-depleted T cell subsets. The presence of measles virus RNA was detected in PBMC isolated from measles patients, and the production of the immunoreactive hemagglutinin protein was defective in these cells.

scholarly journals Monocyte tissue factor induction by lipopolysaccharide (LPS): dependence on LPS-binding protein and CD14, and inhibition by a recombinant fragment of bactericidal/permeability-increasing protein

Blood ◽  
1994 ◽  
Vol 83 (9) ◽  
pp. 2516-2525 ◽  
Author(s):  
K Meszaros ◽  
S Aberle ◽  
R Dedrick ◽  
R Machovich ◽  
A Horwitz ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Binding Protein ◽  
Mononuclear Phagocytes ◽  
Factor Vii ◽  
Peripheral Blood Mononuclear ◽  
Recombinant Fragment

Abstract Mononuclear phagocytes, stimulated by bacterial lipopolysaccharide (LPS), have been implicated in the activation of coagulation in sepsis and endotoxemia. In monocytes LPS induces the synthesis of tissue factor (TF) which, assembled with factor VII, initiates the blood coagulation cascades. In this study we investigated the mechanism of LPS recognition by monocytes, and the consequent expression of TF mRNA and TF activity. We also studied the inhibition of these effects of LPS by rBPI23, a 23-kD recombinant fragment of bactericidal/permeability increasing protein, which has been shown to antagonize LPS in vitro and in vivo. Human peripheral blood mononuclear cells, or monocytes isolated by adherence, were stimulated with Escherichia coli O113 LPS at physiologically relevant concentrations (> or = 10 pg/mL). The effect of LPS was dependent on the presence of the serum protein LBP (lipopolysaccharide-binding protein), as shown by the potentiating effect of human recombinant LBP or serum. Furthermore, recognition of low amounts of LPS by monocytes was also dependent on CD14 receptors, because monoclonal antibodies against CD14 greatly reduced the LPS sensitivity of monocytes in the presence of serum or rLBP. Induction of TF activity and mRNA expression by LPS were inhibited by rBPI23. The expression of tumor necrosis factor showed qualitatively similar changes. Considering the involvement of LPS-induced TF in the potentially lethal intravascular coagulation in sepsis, inhibition of TF induction by rBPI23 may be of therapeutic benefit.

scholarly journals The 2′-O-methylation status of a single guanosine controls transfer RNA–mediated Toll-like receptor 7 activation or inhibition

2012 ◽  
Vol 209 (2) ◽  
pp. 235-241 ◽  
Author(s):  
Stefanie Jöckel ◽  
Gernot Nees ◽  
Romy Sommer ◽  
Yang Zhao ◽  
Dmitry Cherkasov ◽  
...  
Keyword(s):  
Influenza A ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Thermus Thermophilus ◽  
Methylation Status ◽  
Transfer Rna ◽  
Type I ◽  
Peripheral Blood Mononuclear ◽  
Molecular Pattern

Foreign RNA serves as pathogen-associated molecular pattern (PAMP) and is a potent immune stimulator for innate immune receptors. However, the role of single bacterial RNA species in immune activation has not been characterized in detail. We analyzed the immunostimulatory potential of transfer RNA (tRNA) from different bacteria. Interestingly, bacterial tRNA induced type I interferon (IFN) and inflammatory cytokines in mouse dendritic cells (DCs) and human peripheral blood mononuclear cells (PBMCs). Cytokine production was TLR7 dependent because TLR7-deficient mouse DCs did not respond and TLR7 inhibitory oligonucleotides inhibited tRNA-mediated activation. However, not all bacterial tRNA induced IFN-α because tRNA from Escherichia coli Nissle 1917 and Thermus thermophilus were non-immunostimulatory. Of note, tRNA from an E. coli knockout strain for tRNA (Gm18)-2′-O-methyltransferase (trmH) regained immunostimulatory potential. Additionally, in vitro methylation of this immunostimulatory Gm18-negative tRNA with recombinant trmH from T. thermophilus abolished its IFN-α inducing potential. More importantly, Gm18-modified tRNA acted as TLR7 antagonist and blocked IFN-α induction of influenza A virus–infected PBMCs.

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