Thymic alterations induced by partial hepatectomy: Upregulation of glycoprotein 96, CD91 and TLR2 and generation of regulatory T cells.

Glycoprotein 96 (gp96) is an endoplasmic reticulum (ER)-resident heat shock protein. It controls the folding of nascent membrane-spanning and secretory proteins, participates in stress-induced unfolded protein response (UPR) and in pathways leading to proteolysis of damaged proteins through ER- associated degradation pathways and chaperone- mediated autophagy. In addition, gp96 controls the steroid biosynthesis and Ca2+ homeostasis and participates in insulin-IGF/signaling pathways. Besides, owing to its peptide chaperone capacity and ability to interact with antigen-presenting cells, gp96 has been implicated in priming of innate and adaptive immunity. In an attempt to visualize the intensity of ER-stress in thymus and possible participation of gp96 in generation of auto-reactive T cell clones that were detected in regenerating liver, in this study we investigated the dynamics of gp96 expression in partially hepatectomized (pHx) and sham Hx mice. Simultaneously, we detected the thymic expression of receptors responsible for endocytosis of gp96- chaperoned peptides (CD91) and intracellular activation of ER-stress pathways (TLR2), as well as the expression of TGF-β and the distribution of CD4+CD25+FoxP3+ cells. The data have shown that both pHx and sham Hx induced an accelerated apoptosis and hypoplasia in thymus. Partial Hx induced, however, a higher expression of gp96, the translocation of the CD91, TLR2 and TGF-β immunostaining from medulla to cortex and an appearance of Treg cells. The data show that pHx triggers in thymus the ER stress and UPR response and suggest that gp96 participates in the generation of natural Treg cells, which might be involved in the control of liver regeneration in the periphery

Comparative study of frequency of different lymphocytes subpopulation in peripheral blood of patients with prostate cancer and benign prostatic hyperplasia

PURPOSE: Benign prostatic hyperplasia (BPH) and prostate cancer (PC) are the most common urologic diseases among men over fifty and, until recently, they were considered to be caused by the impaired immune response. Despite many studies designed to investigate T-cell-based antitumor immunity, the role of innate immune cells in BPH and PC is still poorly understood. In this study the frequency of different leukocytes subpopulation in peripheral blood of BPH, PC patients and in healthy volunteers was analysed and compared. METHODS: In a cross-sectional study 60 subjects were enrolled (20 patients with BPH or with PC and 20 healthy volunteers). Peripheral blood mononuclear cells (PBMC) were isolated and the percentage of T lymphocytes, natural killer (NK) and NKT cells, as well as subsets of T lymphocytes [CD3(+)CD56(-)CD4(+), T-regs (CD4(+)CD25(+)FoxP3(+)) and CD3(+)CD56(-)CD8(+)] and NK cells (CD3(-)CD56(+dim) and CD3(-)CD56(+bright)) were analysed by flow cytometry. Intracellular content of interleukin-4 (IL-4) and interferon gamma (IFN gamma in T lymphocytes, NK and NKT cells were also detected. RESULTS: The percentage of T lymphocytes and their subsets in peripheral blood lymphocytes did not differ among investigated groups, while the frequency of Tregs was the highest in PC patients. The percentage of NK cell and their subsets did not differ among investigated groups. Negative correlation between PSA value, percentage of T lymphocytes and NK cells was observed only in PC patients. Highly positive correlation between the PSA value and the percentage of Tregs was found in PC patients. CONCLUSION: Different frequencies in distinctly lymphocyte subpopulation in peripheral blood of healthy men, BPH and PC patients could be responsible for occurrence and progression of prostatic hyperplasia or tumour. Due to the ability of tumours to suppress the cognate T cell immune response, the cells of innate immunity (NKT and Tregs) may be playing a key role in the immunopathogenesis of PC and BPH

Expression of cytolytic protein–perforin in peripheral blood lymphocytes in severe traumatic brain injured patients

Purpose: The purpose of this study was to investigate the changes of cytotoxic protein-perforin in peripheral blood lymphocytes in severe TBI patients and possible correlation between severity of TBI and perforin expression. Methods: Flow cytometry was used for simultaneous detection of intracellular perforin and cell surface antigens of peripheral blood lymphocytes of 20 severe TBI patients on day 1, 4 and 7 after the onset of injury. Peripheral blood mononuclear cells from 20 healthy volunteers were used as control. Clinical and laboratory parameters were also recorded. Results: There was a statistically significant decrease of perforin-positive lymphocytes including T, natural killer (NK) and NKT cells on day 4 as compared with day 1 after the brain injury or healthy controls. On day 7, perforin expression was restored in lymphocyte of cytotoxic phenotype (CD8 + T lymphocytes, NK cells, and NKT cells) compared with day 1. High positive correlation was found between the severity of TBI and frequency of perforin-positive cells on day 4 when the occurrence of the intra-hospital infections was the highest. Conclusion: Severe TBI significantly decreases perforin expression in T lymphocytes, NK and NKT cells, which indicate a possible mechanism underlying the high susceptibility to infections. © 2010 Elsevier Ltd. All rights reserved