Heat shock proteins and human pathogens

1995 ◽  
Vol 73 (S1) ◽  
pp. 1077-1080 ◽  
Author(s):  
J. P. Burnie

Recent years have seen the identification of heat shock protein 90 (HSP90) as one of sthe key immunodominant antigens in systemic fungal infection. In disseminated candidiasis, patients seroconvert when they recover from the infection. In a mouse model of infection, human, mouse, and human recombinant antibody all showed a degree of protection. HSP90 is also immunodominant in patients with an aspergilloma, allergic bronchopulmonary aspergillosis, and invasive aspergillosis who mount an antibody response. This paper argues the case for immunotherapy with antibody in treating these serious infections. Key words: heat shock protein 90, invasive candidiasis, invasive aspergillosis, immunotherapy.

2009 ◽  
Vol 423 (3) ◽  
pp. 411-419 ◽  
Author(s):  
Andrew J. Ramsey ◽  
Lance C. Russell ◽  
Michael Chinkers

Steroid-hormone-receptor maturation is a multi-step process that involves several TPR (tetratricopeptide repeat) proteins that bind to the maturation complex via the C-termini of hsp70 (heat-shock protein 70) and hsp90 (heat-shock protein 90). We produced a random T7 peptide library to investigate the roles played by the C-termini of the two heat-shock proteins in the TPR–hsp interactions. Surprisingly, phages with the MEEVD sequence, found at the C-terminus of hsp90, were not recovered from our biopanning experiments. However, two groups of phages were isolated that bound relatively tightly to HsPP5 (Homo sapiens protein phosphatase 5) TPR. Multiple copies of phages with a C-terminal sequence of LFG were isolated. These phages bound specifically to the TPR domain of HsPP5, although mutation studies produced no evidence that they bound to the domain's hsp90-binding groove. However, the most abundant family obtained in the initial screen had an aspartate residue at the C-terminus. Two members of this family with a C-terminal sequence of VD appeared to bind with approximately the same affinity as the hsp90 C-12 control. A second generation pseudo-random phage library produced a large number of phages with an LD C-terminus. These sequences acted as hsp70 analogues and had relatively low affinities for hsp90-specific TPR domains. Unfortunately, we failed to identify residues near hsp90's C-terminus that impart binding specificity to individual hsp90–TPR interactions. The results suggest that the C-terminal sequences of hsp70 and hsp90 act primarily as non-specific anchors for TPR proteins.


2017 ◽  
Vol 373 (1738) ◽  
pp. 20160527 ◽  
Author(s):  
Abbey D. Zuehlke ◽  
Michael A. Moses ◽  
Len Neckers

The molecular chaperone heat shock protein 90 (Hsp90) facilitates metastable protein maturation, stabilization of aggregation-prone proteins, quality control of misfolded proteins and assists in keeping proteins in activation-competent conformations. Proteins that rely on Hsp90 for function are delivered to Hsp90 utilizing a co-chaperone–assisted cycle. Co-chaperones play a role in client transfer to Hsp90, Hsp90 ATPase regulation and stabilization of various Hsp90 conformational states. Many of the proteins chaperoned by Hsp90 (Hsp90 clients) are essential for the progression of various diseases, including cancer, Alzheimer's disease and other neurodegenerative diseases, as well as viral and bacterial infections. Given the importance of these clients in different diseases and their dynamic interplay with the chaperone machinery, it has been suggested that targeting Hsp90 and its respective co-chaperones may be an effective method for combating a large range of illnesses. This article is part of the theme issue ‘Heat shock proteins as modulators and therapeutic targets of chronic disease: an integrated perspective’.


2014 ◽  
Vol 58 (4) ◽  
pp. 1889-1896 ◽  
Author(s):  
Frédéric Lamoth ◽  
Praveen R. Juvvadi ◽  
Erik J. Soderblom ◽  
M. Arthur Moseley ◽  
Yohannes G. Asfaw ◽  
...  

ABSTRACTHeat shock protein 90 (Hsp90) is an essential chaperone involved in the fungal stress response that can be harnessed as a novel antifungal target for the treatment of invasive aspergillosis. We previously showed that genetic repression of Hsp90 reducedAspergillus fumigatusvirulence and potentiated the effect of the echinocandin caspofungin. In this study, we sought to identify sites of posttranslational modifications (phosphorylation or acetylation) that are important for Hsp90 function inA. fumigatus. Phosphopeptide enrichment and tandem mass spectrometry revealed phosphorylation of three residues in Hsp90 (S49, S288, and T681), but their mutation did not compromise Hsp90 function. Acetylation of lysine residues of Hsp90 was recovered after treatment with deacetylase inhibitors, and acetylation-mimetic mutations (K27A and K271A) resulted in reduced virulence in a murine model of invasive aspergillosis, supporting their role in Hsp90 function. A single deletion of lysine K27 or an acetylation-mimetic mutation (K27A) resulted in increased susceptibility to voriconazole and caspofungin. This effect was attenuated following a deacetylation-mimetic mutation (K27R), suggesting that this site is crucial and should be deacetylated for proper Hsp90 function in antifungal resistance pathways. In contrast to previous reports inCandida albicans, the lysine deacetylase inhibitor trichostatin A (TSA) was active alone againstA. fumigatusand potentiated the effect of caspofungin against both the wild type and an echinocandin-resistant strain. Our results indicate that the Hsp90 K27 residue is required for azole and echinocandin resistance inA. fumigatusand that deacetylase inhibition may represent an adjunctive anti-Aspergillusstrategy.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Eleni Papakonstantinou ◽  
Triantafyllia Koletsa ◽  
Liang Zhou ◽  
Lei Fang ◽  
Michael Roth ◽  
...  

Abstract Background Bronchial thermoplasty regulates structural abnormalities involved in airway narrowing in asthma. In the present study we aimed to investigate the effect of bronchial thermoplasty on histopathological bronchial structures in distinct asthma endotypes/phenotypes. Methods Endobronchial biopsies (n = 450) were collected from 30 patients with severe uncontrolled asthma before bronchial thermoplasty and after 3 sequential bronchial thermoplasties. Patients were classified based on blood eosinophils, atopy, allergy and smoke exposure. Tissue sections were assessed for histopathological parameters and expression of heat-shock proteins and glucocorticoid receptor. Proliferating cells were determined by Ki67-staining. Results In all patients, bronchial thermoplasty improved asthma control (p < 0.001), reduced airway smooth muscle (p = 0.014) and increased proliferative (Ki67 +) epithelial cells (p = 0.014). After bronchial thermoplasty, airway smooth muscle decreased predominantly in patients with T2 high asthma endotype. Epithelial cell proliferation was increased after bronchial thermoplasty in patients with low blood eosinophils (p = 0.016), patients with no allergy (p = 0.028) and patients without smoke exposure (p = 0.034). In all patients, bronchial thermoplasty increased the expression of glucocorticoid receptor in epithelial cells (p = 0.018) and subepithelial mesenchymal cells (p = 0.033) and the translocation of glucocorticoid receptor in the nucleus (p = 0.036). Furthermore, bronchial thermoplasty increased the expression of heat shock protein-70 (p = 0.002) and heat shock protein-90 (p = 0.001) in epithelial cells and decreased the expression of heat shock protein-70 (p = 0.009) and heat shock protein-90 (p = 0.002) in subepithelial mesenchymal cells. The effect of bronchial thermoplasty on the expression of heat shock proteins -70 and -90 was distinctive across different asthma endotypes/phenotypes. Conclusions Bronchial thermoplasty leads to a diminishment of airway smooth muscle, to epithelial cell regeneration, increased expression and activation of glucocorticoid receptor in the airways and increased expression of heat shock proteins in the epithelium. Histopathological effects appear to be distinct in different endotypes/phenotypes indicating that the beneficial effects of bronchial thermoplasty are achieved by diverse molecular targets associated with asthma endotypes/phenotypes.


2004 ◽  
Vol 32 (4) ◽  
pp. 636-639 ◽  
Author(s):  
M. Triantafilou ◽  
K. Triantafilou

Mammalian responses to bacterial LPS (lipopolysaccharide) from the outer membrane of Gram-negative bacteria can lead to an uncontrolled inflammatory response that can be deadly for the host. It has been shown that the innate immune system employs at least three cell surface receptors, CD14, TLR4 (Toll-like receptor 4) and MD-2, in order to recognize bacterial LPS. In our previous work we have found that Hsps (heat-shock proteins) are also involved in the innate recognition of bacterial products. Their presence on the cell surface, as well as their involvement in the innate recognition process, are poorly understood. In the present study we have investigated the association of TLR4 with Hsp70 and Hsp90 following LPS stimulation, both on the cell surface and intracellularly. Our results show that Hsp70 and Hsp90 form a cluster with TLR4 within lipid microdomains following LPS stimulation. In addition, Hsp70 and Hsp90 seem to be involved in TLR4/LPS trafficking and targeting to the Golgi apparatus, since upon LPS stimulation we found that both Hsps are targeted to the Golgi along with TLR4. The present study sheds new light into the involvement of Hsps in the innate immune response.


2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
David Wenkert ◽  
Bernadette Ramirez ◽  
Yuehai Shen ◽  
Michael A. Kron

Geldanamycin (GA) is a benzoquinone-containing ansamycin that inhibits heat shock protein 90. GA derivatives are being evaluated as anti-neoplastic agents, but their utility against parasites whose heat shock proteins (Hsps) have homology with human Hsp90 is unknown. The activities of four synthetic GA derivatives were testedin vitrousing adultBrugia malayiandSchistosoma japonicum. Two of the derivatives, 17-N-allyl-17-demethoxygeldanamycin (17-AAG) and 17-N-(2-dimethylaminoethylamino)-17-demethoxygeldanamycin (DMAG), are currently in human clinical trials as anticancer drugs. Using concentrations considered safe peak plasma concentrations for these two derivatives, all four derivatives were active against both parasites. The less toxic derivative 17-AAG was as effective as GA in killingS. japonicum, and both DMAG and 5′-bromogeldanoxazinone were more active than 17-AAG againstB. malayi. This work supports continued evaluation of ansamycin derivatives as broad spectrum antiparasitic agents.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Didier Picard ◽  
Ernest Abboud ◽  
Lilia Bernasconi

The recombinant antibody H90-10 detects the endogenous human heat-shock protein 90 beta (Hsp90β) by immunoprecipitation (IP) and Western blotting.


2011 ◽  
Vol 55 (7) ◽  
pp. 3295-3304 ◽  
Author(s):  
Arnold Louie ◽  
Daniel S. Stein ◽  
Julia Z. Zack ◽  
Weiguo Liu ◽  
Haley Conde ◽  
...  

ABSTRACTSystemic candidiasis causes significant mortality in patients despite amphotericin B (AMB) therapy. Mycograb C28Y variant, a human recombinant antibody fragment to heat shock protein 90, is closely related to Mycograb, which showed a survival advantage in combination with AMB in a phase III human trial. The Mycograb C28Y variant could potentially increase the antifungal effect of AMB. In our study, the interaction between AMB-desoxycholate (DAMB) and the Mycograb C28Y variant was characterizedin vitroby using a checkerboard method. Quantitative cultures of kidneys, livers, and spleens of neutropenic mice with systemicCandida albicansinfections were used to assess thein vivointeraction between 1.4 mg/kg of body weight/day of DAMB and 0.15, 1.5, and 15 mg/kg/day of the Mycograb C28Y variant after 1, 3, and 5 days of therapy. DAMB and Mycograb C28Y variant monotherapies, vehicle, and a no-treatment arm served as controls. Also, single- and multidose pharmacokinetics for the Mycograb C28Y variant were determined. Indifference or synergy between DAMB and the Mycograb C28Y variant was seen in two trials by the checkerboard method. The pharmacokinetics of the Mycograb C28Y variant was best described by a 2-compartment model with a median serumt1/2αof ∼0.198 h and at1/2βof ∼1.77 h. In mice, DAMB together with the Mycograb C28Y variant was no more effective than AMB alone (P> 0.05 by analysis of variance). The Mycograb C28Y variant alone had no antifungal activity. We therefore conclude that the Mycograb C28Y variant in combination with DAMB offered no benefit over DAMB monotherapy in a neutropenic murine model of systemic candidiasis.


2001 ◽  
Vol 120 (5) ◽  
pp. A357-A357
Author(s):  
T YOH ◽  
T NAKASHIMA ◽  
Y SUMIDA ◽  
Y KAKISAKA ◽  
H ISHIKAWA ◽  
...  

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