Development of the primer set for the detection of the hsp60 gene in Trichophyton mentagrophytes cDNA

Molecular detection and characterisation of fungal heat shock protein 60

Heat shock proteins (Hsp) are highly conserved molecules, which are both constitutively expressed and up-regulated in response to various stress conditions. In particular, fungal Hsp60 can act as immunodominant antigens and facilitate powerful immunological properties. A possible cellular heat shock response was investigated in eight fungi (Aspergillus fumigatus, Aspergillus terreus, Penicillium chrysogenum, Cladosporium cladosporioides, Scedosporium apiospermum, Trichophyton mentagrophytes, Candida albicans and Saccharomyces cerevisiae). Fully automated RNA extraction was followed by quantitative real-time RT-PCR targeting fungus-specific Hsp60 mRNA and sequencing of the amplicon. Levels of temperature-dependent gene expression were evaluated and rates of similarity and identity were compared. While Hsp60 mRNA was constitutively expressed in all the samples tested, a temperature-dependent induction was not shown in C. cladosporioides. In the 80-amino acid fragment from the hypothetical protein, 66% of the amino acids were identical, 20% showed a conserved and 8% a semi-conserved substitution. Our findings should contribute to a better understanding of host-pathogen relationship and suggest that fungal Hsp60 under temperature-related stress conditions might act as an immunogenic trigger in orchestrating fungi-related diseases.

Characterization and temperature-dependent quantification of heat shock protein 60 of the immunogenic fungus Alternaria alternata

Heat shock proteins or chaperones are found in mitochondrial and cytosolic compartments of cells. They are responsible for the correct folding of proteins and are up-regulated in reaction to various stressors. In addition, when released or presented on the surface of cells, they may play an important role in inflammatory and immunomodulating processes. To identify and characterize hsp60 in the common environmental mold Alternaria alternata, the fungus was cultivated and incubated at different temperatures to induce a possible heat shock response. Fully automated RNA extraction was followed by quantitative real-time RT-PCR targeting A. alternata specific Hsp60 mRNA and subsequent sequencing of the amplicon. While Hsp60 mRNA was constitutively expressed in all samples tested, a temperature-dependent expression of Hsp60 mRNA was observed. Sequencing revealed an identity of more than 85% to other fungal hsp60, indicating the existence of this protein in A. alternata.

Recombinant protein and DNA vaccines derived from hsp60 Trichophyton mentagrophytes control the clinical course of trichophytosis in bovine species and guinea-pigs

Heat shock proteins (hsp) were identified in many infectious agents as immunodominant antigens with a protective effect. Immunization of laboratory animals by selected representants of hsp60, hsp70 and hsp90 isolated from several pathogens induced protective host immunity and significantly reduced clinical manifestation of infection. The present study involves preparation of a recombinant protein vaccine and a DNA vaccine. Both vaccines were derived from the hsp60 of the dermatophyte, Trichophyton mentagrophytes. Challenge trials with evaluation of the protective effect of vaccination were performed on calves and guinea-pigs. Both vaccination procedures reduced, in statistically significant fashion, the clinical course of skin mycosis in calves experimentally inoculated with the dermatophyte, T. mentagrophytes. In experiments with guinea-pigs, increased protection was only seen with DNA vaccination. After DNA vaccine application, no paravaccination side-effects (granulomas at the injection site, changed total state of the animal) were observed. Only vaccination with the recombinant protein in calf's experiment induced specific serum antibodies. This observation indicates that antibodies are not associated with protection. In summary, DNA vaccine hsp60 is the most promising for prevention of bovine trichophytosis.

Isolation and characterization of an immunogenic fragment of heat shock protein 60 from Trichophyton mentagrophytes. Isolierung und Charakterisierung eines immunogenen Fragmentes des Hitzeschockproteins 60 von Trichophyton mentagrophytes

Heat shock protein 60 (hsp60) were isolated from several fungal, protozoal and many bacterial pathogens and successfully used for protective vaccination in some infection models. This work focuses on the isolation of recombinant hsp60 from the dermatophyte, Trichophyton mentagrophytes as a potentially protective antigen in trichophytosis. With the help of a previously tested set of degenerated primers, it was used reverse transcriptase polymerase chain reaction (RT-PCR) for isolation of partial cDNA of the hsp60 T. mentagrophytes (labelled hsp60-TM814), which was cloned into cloning vector. The sequencing of hsp60-TM814 cDNA and global alignment confirmed homology of the hsp60-TM814 with other members of the hsp60 family. Hsp60-TM814 cDNA corresponds to the region encoding the immunoprotective fragment of the hsp60 from Histoplasma capsulatum, used successfully in mouse model of histoplasmosis. A recombinant fragment (r-hsp60-TM664), 220 amino acids in length, was prepared in a prokaryote expression system, and its identity confirmed by mass spectroscopy. High immunogenicity of r-hsp60-TM664 was proven after subcutaneous immunization of mice. Immunized mouse sera recognized r-hsp60-TM664 on Western blots as well as hsp60 from mouse liver lysate and lysate of Candida albicans.