Detection of antigens in mycelial and in arthroconidial phases of Trichophyton mentagrophytes

Pathogenesis of tinea

Dermatophytes are hyphomycetes that can degrade keratin. This puts them in a position to cause infections of the keratin-containing superficial skin. The resulting clinical picture is called tinea. The pathogenesis and course of tinea is decisively determined by pathogen-related factors and by the defense mechanisms of the host. An infection starts with an adherence of fungal propagules, followed by the formation of hyphae that can spread within the tissue. This process is accompanied by a release of fungal enzymes and other pathogenic factors. Next keratinocytes are activated, the epidermal barrier is destroyed, epidermal proliferation is enhanced and defensins are expressed within the epidermis. In addition, innate and specific immune responses are initiated, involving neutrophilic granulocytes, macrophages, antibodies and T cells. The cellular mechanisms are thought to be crucial for healing. Special conditions apply to nail infections, because within nail plates the fungi are not accessible to effective defense mechanisms, as well as to infections of hair follicles that contain specific concentrations of steroid hormones. Dermatophytes that penetrate into the dermis can cause granulomatous inflammatory reactions and systemic immune reactions are supposed to be a trigger of so-called id reactions.

Use of western blot to study Microsporum canis antigenic proteins in canine dermatophytosis

Western blotting was used to describe the Microsporum canis proteins with antigenic activity in dogs with dermatophytosis. Electrophoretic separation of whole fungal strain extract cultured from a cat was performed under denaturing conditions. The proteins were blotted onto nitrocellulose and probed with sera collected from 22 dogs with dermatophytosis (18 M. canis, 3 M. gypseum, 1 Trichophyton mentagrophytes; group A), 20 dogs with skin diseases other than dermatophytosis, and 22 dogs with no clinical cutaneous signs (group B, n = 42). Nine principal IgG-binding proteins with apparent molecular weights of 180, 144, 130, 120, 102, 96, 80, 68, and 48 kD were visualised on group A blots. For these proteins, serological cross-reactivity with different strains of M. canis may be indirectly confirmed, whereas additional proteins were found to react with sera from individual dogs. The proteins visualised in this study may represent diagnostic markers of dermatophyte infection. The proteins should be further evaluated for their role in the cellular immune response of dogs with dermatophytosis.

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.

Immunoelectrophoretic analysis of medium-derived antigens bound to the surface of Mycoplasma hominis, Mycoplasma fermentans and Ureaplasma urealyticum

We analyzed Mycoplasma hominis, Mycoplasma fermentans and Ureaplasma urealyticum antigens by immunochemical methods. The immunochemical reaction showed that all three species bound to the surface of one medium component, which origin stemmed from the horse serum. This substance functioned as one of the most potent components of mycoplasma immunogens for all three species.