Near Infrared Photo-Antimicrobial Targeting Therapy For Candida Albicans

Drug-resistant microorganisms are a pressing issue, and innovative antimicrobial therapies are required; antibodies targeting antigens on pathogen surfaces have emerged as one such modality. IgY, abundant in chicken egg yolk, confers passive immunity, and is effective against various pathogens; however, its antimicrobial effects remain limited. Near-infrared photoimmunotherapy (NIR-PIT), originally developed as a cancer treatment, specifically kills cancer cells via a photosensitizing phthalocyanine dye (IRDye700Dx; IR700)-conjugated monoclonal antibody, and irradiating NIR light. IgY-photo-antimicrobial targeting therapy (IgY-PAT(2)), exploiting NIR-PIT, is investigated to destroy only microorganisms. IR700 is conjugated with anti-Candida albicans IgY (CA-IgY) to generate CA-IgY-IR700, which specifically binds various Candida spp. (and not human skin cells). The antimicrobial effect of CA-IgY-PAT(2) is dependent on the NIR-light dose (p < 0.0001). CA-IgY-PAT(2) significantly reduces the area of ulcers in a mouse model of CA-infected cutaneous ulcers (p < 0.0001), indicating that CA-IgY-PAT(2) is a new promising therapeutic method for CA infection.