Application Of Heat Shock Proteins Research Articles

Heat Shock Proteins as Targets for Novel Antimalarial Drug Discovery.

Plasmodium falciparum, the parasitic agent that is responsible for a severe and dangerous form of human malaria, has a history of long years of cohabitation with human beings with attendant negative consequences. While there have been some gains in the fight against malaria through the application of various control measures and the use of chemotherapeutic agents, and despite the global decline in malaria cases and associated deaths, the continual search for new and effective therapeutic agents is key to achieving sustainable development goals. An important parasite survival strategy, which is also of serious concern to the scientific community, is the rate at which the parasites continually develop resistance to drugs. Among the key players in the parasite's ability to develop resistance, maintain cellular integrity, and survives within an unusual environment of the red blood cells are the molecular chaperones of the heat shock proteins (HSP) family. HSPs constitute a novel avenue for antimalarial drug discovery and by exploring their ubiquitous nature and multifunctional activities, they may be suitable targets for the discovery of multi-targets antimalarial drugs, needed to fight incessant drug resistance. In this chapter, features of selected families of plasmodial HSPs that can be exploited in drug discovery are presented. Also, known applications of HSPs in small molecule screening, their potential usefulness in high throughput drug screening, as well as possible challenges are highlighted.

Immunoregulatory properties of Hsp70

Heat shock proteins 70 (Hsp70) play an important role in maintaining cellular homeostasis. As molecular chaperones, Hsp70 are responsible for proper folding of newly synthesized polypeptides and refolding of misfolded and aggregated proteins. Hsp70 are involved in cellular transport and participate in signal transduction processes. The presence of Hsp70 in the extracellular space is associated with development of various pathological conditions, including autoimmune and cancer diseases. Recent data suggest anti-inflammatory property of Hsp70 confirmed in both in vitro and animal models. This paper summarizes recent data regarding immunoregulatory properties of Hsp70, and presents promising results of the studies concerning the application of heat shock proteins in treatment of chronic inflammatory diseases.

Heat shock proteins in porcine ovary: synthesis, accumulation and regulation by stress and hormones.

The present studies aimed to understand the interrelationships between stress, hormones and heat shock proteins (HSPs) in the ovary. We examined (1) whether HSP70.2, HSP72 and HSP105/110 can be produced and accumulated in porcine ovarian tissue, (2) whether these HSPs could be indicators of stress, i.e. whether two kinds of stress (high temperatures and malnutrition/serum deprivation) can affect them, and (3) whether some hormonal regulators of ovarian functions (insulin-like growth factor (IGF)-I, leptin and follicle-stimulating hormone (FSH)) can affect these HSPs and response of ovaries to HSP-related stress. We analysed the expression of HSP70.2, HSP72 and HSP105/110 mRNA (by using real-time reverse transcriptase polymerase chain reaction) in porcine ovarian granulosa cells, as well as the accumulation of HSP70 protein (by using sodium dodecyl sulphate polyacrylamide gel electrophoresis-Western) in either whole ovarian follicles and granulose cells cultured at normal (37.5°C) or high (41.5°C) temperature, with and without serum and with and without IGF-I, leptin and FSH. Expression of mRNA for HSP70.2, HSP72 and HSP105/110 in ovarian granulosa cells and accumulation of HSP70 protein in whole ovarian follicles and granulosa cells were demonstrated. In all the groups, addition of either IGF-I, leptin and FSH reduced the expression of HSP70.2, HSP72 and HSP105/110 mRNA. Both high temperature, serum deprivation and their combination resulted in increase in mRNAs for all three analysed HSPs. Additions of either IGF-I, leptin and FSH prevented the stimulatory effect of both high temperature and serum deprivation on the transcription of HSP70.2, HSP72 and HSP105/110. In contrast, high temperature reduced accumulation of peptide HSP70 in both ovarian follicles and granulosa cell. Serum deprivation promoted accumulation of HSP70 in granulosa cells, but not in ovarian follicles. Addition of IGF-I, leptin and FSH was able to alter accumulation of HSP70 in both follicles and granulosa cells. The present observations suggest (1) that HSPs can be synthesised in ovarian follicular granulosa cells; (2) that hormones (IGF-I, leptin and FSH) can inhibit, whilst stressors (both high temperature and malnutrition/serum deprivation) can stimulate transcription of HSP70.2, HSP72 and HSP105/110 genes, whilst heat stress, but not malnutrition, can promote depletion of HSP70 in ovarian cells, and (3) that hormones (IGF-I, leptin and FSH) can prevent stress-related changes in HSPs. The application of HSPs as indicators and mediators of stress and hormones on ovarian functions, as well as use of hormones and HSPs as anti-stressor molecules, are discussed.

Application of heat shock proteins as stress markers in aquatic organisms using endemic Baikal amphipods as an example

When heat shock proteins (HSPs) are used as biomarkers in monitoring studies of aquatic ecosystems, it is necessary to take into account the specificity of synthesis of these proteins in various organisms. This especially applies to endemic species and species with narrow ranges of adaptation for specific conditions in certain water bodies. In this study, we assessed the possibility to use HSPs as molecular stress markers in species with a narrow niche breadth using endemic Baikal amphipods (Crustacea, Amphipoda) as an example. The effect of stress induced by toxicants and temperature has been assessed. Proteins of families HSP70 and low-molecular-weight HSP related to alpha-crystallins were used as biomarkers. Temperature- and toxicant-induced stresses induced low-molecular-weight HSP synthesis in the endemic amphipod species studied. However, induction of HSP70 synthesis in the same species after temperature stress has not been detected. The specificity of synthesis of HSP70 is discussed. The results obtained in this study suggest that low-molecular-weight HSPs can be used as stress markers in Baikal species and species with a narrow niche breadth.

Combined Use of Dendritic Cells Enhances Specific Antileukemia Immunity by Leukemia Cell-Derived Heat Shock Protein 70 in a Mouse Model with Minimal Residual Leukemia Cells

We have reported that immunotherapy using leukemia cell-derived heat shock proteins (HSPs) is effective against minimal residual disease (MRD) after syngeneic stem cell transplantation (SCT) in mice. However, leukemia patients after SCT are usually immunocompromised and immunologically tolerant to leukemia cells. We investigated whether the use of dendritic cells (DCs) in combination with HSP70 enhances cytotoxicity against B-cell leukemia cell line A20 in mice after syngeneic SCT. All unimmunized mice died of leukemia early after A20 cell inoculation, whereas mice immunized with HSP70 or HSP70-pulsed DCs survived significantly longer. Although only 60% of the HSP70-immunized mice survived, all mice immunized with HSP70-pulsed DCs survived without MRD. In addition, the cytotoxicities against A20 cells for splenocytes from mice immunized with HSP70-pulsed DCs were significantly higher than those of HSP70-immunized mice, and the cytotoxicities against A20 cells were significantly blocked by anti-CD8 antibody and by major histocompatibility complex class I antibody, but not by anti-CD4 antibody. Moreover, abnormalities were detected in neither the biochemical data nor the histopathologic findings. These findings indicate that the combined use of DCs and leukemia cell-derived HSP70 enhances the antileukemia effect by inducing the specific cytotoxicities of CD8+ cytotoxic T-cells, thereby eradicating MRD effectively and safely, even in an immunocompromised state after syngeneic SCT. This approach may thus be useful for further application of HSP in leukemia patients after autologous SCT.

Current ideas about applications of heat shock proteins in vaccine design and immunotherapy

Heat shock proteins (HSPs), as molecular chaperones, perform critical functions in maintaining cell homeostasis. Certain HSPs in extra-cellular milieu are capable of modulating innate and adaptive immunity due to their ability to chaperone polypeptides and to interact with the host's immune system, particularly professional antigen presenting cells (APCs). This review summarizes the immunomodulating functions of HSPs and their potential applications in cancer immunotherapy.

Combined Use of Dendritic Cells Enhances Specific Anti-Leukemia Effect of Leukemia Cell-Derived-HSP70 in a Mouse Model with Minimal Residual Leukemia Cells.

Background: Heat shock proteins (HSPs) are molecular chaperones binding a broad repertorie of endogenous antigenic peptides and carrying them to the MHC. Because the identification of each tumor specific antigen is not necessary, the immunotherapy using HSPs is more practical than other immunological procedures. Meanwhile, relapse due to minimal residual disease (MRD) is a big problem of autologous stem cell transplantation (SCT) against leukemia. We previously reported that immunotherapy using leukemia cell-derived HSPs is effective against MRD after syngeneic bone marrow transplantation (BMT) in mice (Sato et al. Blood, 2001). However, patients receiving SCT are usually immunocompromised due to repeated anti-cancer therapies. Accordingly, it is important to enhance the cytotoxicities (CTXs) against leukemia. Dendritic cells (DCs) are known as professional antigen-presenting cells with a specific receptor for HSPs and are expected to play a major role in immunotherapy. In this study, we evaluated whether the vaccination of DCs pulsed with HSP70 enhances the anti-leukemia effect induced by leukemia cell-derived HSP70 after syngeneic BMT and evaluated the safety of this immunotherapy.Methods: Three class-I-identical mouse tumor cell lines (A20: B-cell leukemia; T27A: myeloid leukemia; colo26: colonic carcinoma) and syngeneic balb/c mice were used in this study. HSP70 was purified from tumor cells. DCs were generated from bone marrow cells cultured with GM-CSF. DCs were pulsed with HSP70 (HSP70-pulsed-DCs) in vitro. Mice were received total body irradiation (TBI) and transplanted bone marrow cells after TBI, then inoculated 2.5 x 104 A20 cells intravenously. HSP70 or HSP70-pulsed-DCs was subcutaneously administrated. Survival days of immunized mice were compared using Kaplan and Meier methods. CTXs of splenocytes against A20 cells were determined by 51Cr release assay. Histological findings of liver and knee joint and biochemical data of serum of immunized mice were investigated.Results: All mice without immunization or immunized with DCs alone died from leukemic dissemination within 90 days after A20 inoculation, whereas mice immunized with A20-derived HSP70 (A20-HSP70) or A20-HSP70-pulsed-DCs survived long significantly. Additionally, although only 60% of the mice immunized with A20-HSP70 survived on day 120, all the mice immunized with A20-HSP70-pulsed-DCs survived with no residual leukemia cells over 120 days. Moreover, splenocytes of mice immunized with A20-HSP70-pulsed-DCs showed significantly higher CTXs against A20 cells in vitro compare to those with A20-HSP70 alone. However, no CTXs against A20 cells were induced by immunization with colo26-or T27A-HSP70-pulsed-DCs. These CTXs against A20 cells were significantly blocked by anti-CD8 and anti-MHC class-I, but not by anti-CD4. Additionally, no abnormal findings were detected either in biochemical data of serum or in histopathology of liver and joint tissue in long term immunized mice.Conclusions: Combined use of dendritic cells with leukemia cell-derived HSP70 enhances anti-leukemia effect by inducing specific cytotoxic activities against leukemia cells, and eradicates MRD effectively and safely even for immunocompromised status after syngeneic BMT. This approach would be useful for a further application of HSP in leukemia-patients after autologous SCT.

Therapeutic applications of heat shock proteins.

It has been a long time coming, but now that big phanna is interested, the conference circuit is heating up, and a new journal is on the horizon, shouldn't biotech be paying more attention?