HSP70 in human polymorphonuclear and mononuclear leukocytes: comparison of the protein content and transcriptional activity of HSPA genes

Abstract

Cell-type specific variations are typical for the expression of different members of the HSP70 family. In circulating immune cells, HSP70 proteins interact with units of signaling pathways involved in the immune responses and may promote cell survival in sites of inflammation. In this work, we compared basal HSP70 expression and stressinduced HSP70 response in polymorphonuclear and mononuclear human leukocytes. The intracellular content of inducible and constitutive forms of HSP70 was analyzed in relation to the transcriptional activity of HSPA genes. Hyperthermia was used as the stress model for induction of HSP70 synthesis in the cells. Our results demonstrated that granulocytes (mainly neutrophils) and mononuclear cells differ significantly by both basal HSP70 expression and levels of HSP70 induction under hyperthermia. The differences were observed at the levels of HSPA gene transcription and intracellular HSP70 content. The expression of constitutive Hsс70 protein was much higher in mononuclear cells consisting of monocytes and lymphocytes than in granulocytes. At the same time, intact neutrophils showed increased expression of inducible Hsp70 protein compared to mononuclear cells. Heat treatment induced additional expression of HSPA genes in leukocytes. The most pronounced increase in the expression was observed in polymorphonuclear and mononuclear leukocytes for HSPA1A/B. However, in granulocytes, the induction of the transcription of the HSPA8 gene encoding the Hsc70 protein was significantly higher than in mononuclear cells. These variations in transcriptional activity of HSPA genes and intracellular HSP70 content in different populations of leukocytes may reflect specified requirements for the chaperone activity in the cells with a distinct functional role in the immune system.

Extracellular heat shock protein 70 levels in tumour‐bearing dogs and cats treated with radiation therapy and hyperthermia

“…Boyko et al found an increased expression of stressinducible proteins including HSPs in neutrophil granulocytes in humans. 36 In all species, the total blood neutrophil pool (TBNP) is divided into the circulating neutrophil pool (CNP) and the marginal neutrophil pool (MNP). While the CNP represents the quantitated neutrophil count derived in the routine WBC (white blood count), the MNP is a hidden population, which is associated to the vascular endothelium.…”

“…The differences between species can possibly be explained with the different‐sized compartments of neutrophil granulocytes in the blood of cats and dogs. Boyko et al found an increased expression of stress‐inducible proteins including HSPs in neutrophil granulocytes in humans 36 . In all species, the total blood neutrophil pool (TBNP) is divided into the circulating neutrophil pool (CNP) and the marginal neutrophil pool (MNP).…”

Effect of HEAT therapy in patiEnts with type 2 Diabetes mellitus (HEATED): protocol for a randomised controlled trial

“… 29 30 The HSP and insulin signalling-related gene expression will be determined from polymorphonuclear cells. 31 …”

“…High-sensitivity shotgun mass spectrometry will be used to characterise the lipidome of plasma and polymorphonuclear blood cells 29 30. The HSP and insulin signalling-related gene expression will be determined from polymorphonuclear cells 31…”

“…29 30 The HSP and insulin signalling-related gene expression will be determined from polymorphonuclear cells. 31 Health-related quality of life (QoL) will be assessed using the health survey short form-36. 32 QoL assessment and the enlisted examinations mentioned above will be repeated in the same way within 48 hours after the last bath session.…”