Search results for "heat shock"
showing 10 items of 303 documents
Hyperthermia Enhances CD95-Ligand Gene Expression in T Lymphocytes
2004
Abstract Hyperthermia represents an interesting therapeutic strategy for the treatment of tumors. Moreover, it is able to regulate several aspects of the immune response. Fas (APO-1/CD95) and its ligand (FasL) are cell surface proteins whose interaction activates apoptosis of Fas-expressing targets. In T cells, the Fas-Fas-L system regulates activation-induced cell death, is implicated in diseases in which lymphocyte homeostasis is compromised, and plays an important role during cytotoxic and regulatory actions mediated by these cells. In this study we describe the effect of hyperthermia on activation of the fas-L gene in T lymphocytes. We show that hyperthermic treatment enhances Fas-L-med…
Intensified oxidative and nitrosative stress following combined ALA-based photodynamic therapy and local hyperthermia in rat tumors.
2003
Oxidative stress-related changes in tumors upon localized hyperthermia (HT), 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) and their combination (ALA+HT) were examined after the observation that the antitumor effects of ALA-PDT could be significantly enhanced upon simultaneous application of HT. Rats bearing s.c. DS-sarcomas (0.6–1.0 ml) on the hind foot dorsum were anesthetized and underwent one of the following treatments: (i) ALA-PDT (375 mg/kg 5-ALA i.v.); (ii) localized HT, 43°C for 60 min; (iii) combined ALA-PDT and HT [=ALA+HT]. Appropriate control experiments were also performed. After treatment, tumors were excised and rapidly frozen for later analysis of nitrosative s…
HEAT SHOCK PROTEINS AND AUTOIMMUNE SYSTEM ACTIVATION IN IBD: ARTICULAR MANIFESTATIONS AND THE EPIDEMIOLOGICAL FREQUENCY IN ORTHPEDICS
2013
clinical evidence suggest that arthritis is one of the complications of inflammatori bowel disease (IBD) of which the etiological causes are still not completely understood. Among the possible explanations the most probable theory is poor regulation of the intestinal immune system, which causes a cross-like immune reactivity against the resident micro flora. Arthritis is these subjects involves different joints and is asymmetric, with greater involvement of the large joints of the lower limbs. Joints may also be involved with the spinal forms of sacroileitis and ankilosing spondylitis. This clinical evidence explains the existence of Lesnioski-Crohn's disease, a variant of IBD in which pati…
Immune Response to Tumor Stress Proteins—Implications for Vaccine Development Against Cancer
2000
Publisher Summary Stress proteins or heat shock proteins (HSP) belong to the most conserved proteins. The conservation of stress proteins stems from their basic and vital role in cells: Prevention of protein aggregation under stress and physiological conditions. Stress proteins are important target antigens in autoimmune diseases and during certain bacterial infections. This chapter reviews the immunogenicity of stress proteins of tumor cells, stimulation of T cell response by tumor stress proteins and implications this Tcell response have for immunity against the tumor or autoimmunity. The expression of stress proteins in cancer is altered. An overexpression of constitutively expressed or …
SARS-CoV-2 in patients with cancer: possible role of mimicry of human molecules by viral proteins and the resulting anti-cancer immunity
2021
AbstractA few reports suggest that molecular mimicry can have a role in determining the more severe and deadly forms of COVID-19, inducing endothelial damage, disseminated intravascular coagulation, and multiorgan failure. Heat shock proteins/molecular chaperones can be involved in these molecular mimicry phenomena. However, tumor cells can display on their surface heat shock proteins/molecular chaperones that are mimicked by SARS-CoV-2 molecules (including the Spike protein), similarly to what happens in other bacterial or viral infections. Since molecular mimicry between SARS-CoV-2 and tumoral proteins can elicit an immune reaction in which antibodies or cytotoxic cells produced against t…
HSP90 and HSP70: Implication in Inflammation Processes and Therapeutic Approaches for Myeloproliferative Neoplasms.
2015
Myeloproliferative neoplasms (MPN) are clonal stem cell disorders that lead to the excessive production of one or more blood cell lineages. It has been reported that, in most MPN, inflammatory cytokines are frequently increased, indicating that inflammation plays a crucial role in these disorders. Heat shock proteins (HSP) are induced in response to many stressful conditions from heat shock to hypoxia and inflammation. Besides their chaperone and cytoprotective functions, HSPs are key players during inflammation, hence the term “chaperokine.” Through their chaperone activity, HSP90, a stabilizer of many oncogenes (e.g., JAK2), and HSP70, a powerful antiapoptotic chaperone, tightly regulate …
The Humoral Response in TCR α-/-Mice. Can γδ-T Cells Support the Humoral Immune Response?
2002
An optimal humoral response requires T-cell help; however, it has been questioned if this help comes exclusively from alphabeta-T cells or whether gammadelta-T cells also contribute. We have attempted to answer this question by studying the humoral response in T-cell receptor alpha-chain knockout (alpha-/-) mice, which lack the alphabetaT cell subset. Two model antigens were used to characterize the response: the thymus-independent (TI) antigen native dextran B512 (Dx), and the thymus-dependent (TD) antigen heat shock protein (HSP65) from Mycobacterium tuberculosis. When challenged with Dx, the alpha-/- mice elicited a strong antibody response and formed rudimentary germinal centres (GCs), …
The evolution of the heat-shock protein GroEL from Buchnera, the primary endosymbiont of aphids, is governed by positive selection
2002
The heat-shock protein GroEL is a double-ring-structured chaperonin that assists the folding of many newly synthesized proteins in Escherichia coli and the refolding in vitro, with the cochaperonin GroES, of conformationally damaged proteins. This protein is constitutively overexpressed in the primary symbiotic bacteria of many insects, constituting approximately 10% of the total protein in Buchnera, the primary endosymbiont of aphids. In the present study, we perform a maximum likelihood (ML) analysis to unveil the selective constraints in GroEL. In addition, we apply a new statistical approach to determine the patterns of evolution in this highly interesting protein. The main conclusion d…
Geldanamycin and its derivatives as Hsp90 inhibitors
2012
The Hsp90 molecule, one of the most abundant heat shock proteins in mammalian cells, maintains homeostasis and prevents stress-induced cellular damage. Hsp90 is expressed under normal conditions at a level of about 1-2 Percent of total proteins, while its expression increases 2-10 fold in cancer cells. The two main constitutively expressed isoforms of Hsp90 are known as Hsp90-alpha and Hsp90-beta, and their upregulation is associated with tumor progression, invasion and formation of metastases, as well as development of drug resistance. The Hsp90 is a key target for many newly established, potent anticancer agents containing Hsp90 N-terminal ATP binding inhibitors, such as geldanamycin, and…
Hsp10: Anatomic distribution, functions, and involvement in human disease
2013
There is growing evidence that molecular chaperones/heat shock proteins are involved in the pathogenesis of a number of human diseases, known as chaperonopathies. A better molecular understanding of the pathogenetic mechanisms is essential for addressing new strategies in diagnostics, therapeutics and clinical management of chaperonopathies, including those in which Hsp10 is involved. This chaperonin has been studied for a long time as a member of the mitochondrial protein-folding machine. However, although in normal cells Hsp10 is mainly localized in the mitochondrial matrix, it has also been found during and after stress in other subcellular compartments, such as cytosol, vesicles and sec…