Heat-shock proteins in diagnosis and treatment: an overview of different biochemical and immunological functions.

Heat-shock proteins (HSPs) have been involved in different functions including chaperone activity, protein folding, apoptosis, autophagy and immunity. The HSP families have powerful effects on the stimulation of innate immune responses through Toll-like receptors and scavenger receptors. Moreover, HSP-mediated phagocytosis directly enhances the processing and presentation of internalized antigens via the endocytic pathway in adaptive immune system. These properties of HSPs have been used for development of prophylactic and therapeutic vaccines against infectious and noninfectious diseases. Several studies also demonstrated the relationship between HSPs and drug resistance as well as their use as a novel biomarker for detecting tumors in patients. The present review describes different roles of HSPs in biology and medicine especially biochemical and immunological aspects.

Development of HCV Therapeutic Vaccines Using Hp91 Peptide and Small Heat Shock Protein 20 as an Adjuvant.

BACKGROUND: Hepatitis C Virus (HCV) is a major cause of chronic liver disease in the world. Many studies showed that T-cell responses to HCV Nonstructural Protein 3 (NS3) play an important role in clearing acute HCV infections, thus NS3 can be considered as a suitable candidate antigen for development of a HCV therapeutic vaccine. OBJECTIVE: We used Hp91 peptide and small heat shock protein 20 as an adjuvant for enhancement of NS3-specific humoral and cellular immunity in mice. METHOD: In this study, various NS3 DNA and protein constructs were generated in eukaryotic and prokaryotic expression systems, and their potency in eliciting humoral and cellular immune responses was compared using small Heat shock protein 20 (Hsp20), the High Mobility Group Box 1 protein (HMGB1)-derived peptide (Hp91), and Freund's adjuvant in a BALB/c mouse model. RESULTS: Our results indicated that both the Hsp20 conjugated with NS3 protein and Hp91 significantly enhanced the levels of IgG2a, IgG2b and IFN-γ directed toward Th1 responses compared to other groups. Moreover, the immunostimulatory properties of Hp91 were significantly higher than Hsp20 and Freund's adjuvant in various immunization strategies. Mice immunized by NS3 protein formulated with Freund's adjuvant, and also mixed with Hp91 peptide showed higher secretion of Granzyme B than other groups. CONCLUSION: Hp91 peptide could develop NS3-specific B- and T-cell immune responses as a promising HCV therapeutic vaccine candidate in future.

The Distinct Role of Small Heat Shock Protein 20 on HCV NS3 Expression in HEK-293T Cell Line.

BACKGROUND: Hepatitis C (HCV) is known as a serious blood-borne disease that infects millions of people globally. NS3 is a conserved non-structural sequence of hepatitis C virus which has a major role in activating specific CTL responses. As known, there is no effective vaccine against HCV infection, thus it is required to design a specific regimen of vaccination. Recently, the strong immunological properties of Heat shock proteins (Hsps) led to their use as immunomodulators and an antigen carrier for subunit vaccine candidates. In the current study, the role of Hsp20 was evaluated as a HCV NS3 gene carrier in mammalian cell line. METHODS: At first, the recombinant plasmids of pEGFP-Hsp20, pEGFP-NS3, and pEGFP-Hsp20-NS3 were constructed and their accuracy was confirmed by digestion and sequencing. Then, all recombinant plasmids were transfected into HEK293T cells by Lipofectamine and TurboFect gene delivery systems. Finally, the expression of proteins was assessed by fluorescent microscopy, western blotting, and flow cytometry. RESULTS: In western blotting, the 47, 59, and 79 kDa bands were detected for pEGFP-Hsp20, pEGFP-NS3, and pEGFP-Hsp20-NS3, respectively. The percentage of NS3-Hsp20-GFP protein expression was ∼67% by TurboFect and ∼50% by Lipofectamine indicating high potency of TurboFect delivery system. Furthermore, the expression of Hsp20 (∼83%) was higher than NS3 (∼58%) in the cells transfected by TurboFect using flow cytometry analysis. This result was confirmed in the expression of Hsp20-NS3 fusion (∼67%) in which Hsp20 increased the delivery of HCV NS3 in vitro. The same data were obtained by Lipofectamine transfection reagent. CONCLUSION: Briefly, our data confirmed the role of Hsp20 as a suitable antigen carrier for DNA vaccine design.

Carotenoids: biochemistry, pharmacology and treatment.

Carotenoids and retinoids have several similar biological activities such as antioxidant properties, the inhibition of malignant tumour growth and the induction of apoptosis. Supplementation with carotenoids can affect cell growth and modulate gene expression and immune responses. Epidemiological studies have shown a correlation between a high carotenoid intake in the diet with a reduced risk of breast, cervical, ovarian, colorectal cancers, and cardiovascular and eye diseases. Cancer chemoprevention by dietary carotenoids involves several mechanisms, including effects on gap junctional intercellular communication, growth factor signalling, cell cycle progression, differentiation-related proteins, retinoid-like receptors, antioxidant response element, nuclear receptors, AP-1 transcriptional complex, the Wnt/ß-catenin pathway and inflammatory cytokines. Moreover, carotenoids can stimulate the proliferation of B- and T-lymphocytes, the activity of macrophages and cytotoxic T-cells, effector T-cell function and the production of cytokines. Recently, the beneficial effects of carotenoid-rich vegetables and fruits in health and in decreasing the risk of certain diseases has been attributed to the major carotenoids, ß-carotene, lycopene, lutein, zeaxanthin, crocin (/crocetin) and curcumin, due to their antioxidant effects. It is thought that carotenoids act in a time- and dose-dependent manner. In this review, we briefly describe the biological and immunological activities of the main carotenoids used for the treatment of various diseases and their possible mechanisms of action. LINKED ARTICLES: This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.