The destruction of infectious pathogens by photodynamic therapy (PDT) is an emerging modality.
We demonstrated the efficacy of PDT for the management of cutaneous leishmaniasis in our
previous studies. However, much remains to be done for the improvement of PDT regimens. The
modulation of the immune response by photochemistry is an exciting but under-explored area of
PDT research. The goal of this study is to understand the mechanisms of the augmentation of the
host immune response after PDT of cutaneous leishmaniasis (CL). We found that PDT with
phenoxiazine analogues was capable for induction of Th1 immune response due to stimulation of IL-
12 production by dendritic cells. Single PDT treatment facilitated fast healing of the CL lesions due
to effective parasite eradication and augmentation of the immune system. Comparative study with
different photosensitizers (PS) (porphyrins, pehnoxiazines) demonstrated different
immunomodulating properties of PDT depending on chemical class of PS. Knowing the particular
profiles and immunomodulating properties of the pertinent PSs allows us to select the optimal PS
with regards to both the photodestructive and immunostimulating potential.