Antibodies and agents which can bind to the propeptide of the Int1p protein of yeast microorganisms such as Candida albicans are provided which can be useful in methods for treating or preventing infections arising from such microorganisms. Microorganisms expressing the Int1p protein, such as C. albicans and S. cerevisiae, have shown an ability to immunomodulate host cells which allows infections of these microorganisms to thrive and become virulent. The peptide regions involved in the activation of the Int1p protein are isolated and targeted so as to provide a method of disrupting activation and allow for treatment or prevention of infection by microorganisms expressing the int1p protein. In one preferred embodiment of the invention, an antibody or agent which can bind to the propeptide of the Int1p protein from C. albicans is utilized in methods to prevent or treat infections caused by C. albicans or other microorganisms expressing the Int1p protein.