Characterization of immunologically active peptides from the cell wall of T. mentagrophytes

Strategies for the development of a vaccine against ringworm

Resolution of lesions and subsequent protection against ringworm is primarily associated with the development of a cell-mediated immune (CMI) response, in which stimulation of Type-1 lymphocytes and cytokines such as interleukin-2 (IL-2), IL-12 and interferon gamma are significant. Type-2 lymphocyte activation and antibody formation seem a feature of chronic disease states, rather than protection, and are antagonistic to a Type-1 cell response. Initial studies on ringworm vaccines should be directed at identifying and characterizing dermatophyte antigens elaborated during spore germination and early hyphal growth, and the method of their presentation which best potentiates Type-1 cell-associated events, and primes the recipient for a subsequent CMI response.

Vaccination procedures and the infectivity of dermatophyte lesions

By means of an experimental guinea pig model, the immunogenicities of a live spore vaccine, a killed hyphal cell wall vaccine and a soluble cytoplasmic extract vaccine of Trichophyton mentagrophytes var. erinacei were compared, and their modifying influence on the infectivity and duration of experimental dermatophyte lesions examined. Of the three vaccines, the live-spore one was the most effective and closely simulated the type of immunity which develops following a natural infection. Lesions produced in cell wall vaccinated animals revealed significantly less infectivity and were reduced in duration as compared with lesions in unvaccinated animals. The cytoplasmic extract vaccine had no beneficial effect on the course of experimental infection; indeed it seemed to increase the infectivity of lesions. Acquired resistance to reinfection in a pregnant guinea pig was not passed on to the offspring. Significant levels (titer of greater than or equal to 1:16) of antibody were detected in the sera of all infected and vaccinated animals using an indirect fluorescent antibody technique and germling antigens. Using counterimmunoelectrophoresis, precipitating antibodies were detectable in the sera of all seven animals vaccinated with the cell wall or cytoplasmic extract, in one (20%) of the control animals after reinfection, and none of the four animals injected subcutaneously with the live spore vaccine. Thus no correlation between antibody titer and the severity and duration of lesions was observed. These results endorse the growing hypothesis that cell mediated immunity is of prime importance in protection again dermatophyte invasion and suggests that prophylactic vaccination procedures are worthy of further evaluation in lower animals.