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Systemic Suppression of the Contact Hypersensitivity by the Products of Protoporphyrin IX Photooxidation
Author(s) -
Kyagova Alla A.,
Mansurova Galina V.,
Kozir Lyudmila A.,
Ponomarev Gelii V.,
Pavlov Vsevolod Y.,
Konstantinov Igor O.,
Potapenko Alexander
Publication year - 2005
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1562/2005-04-26-ra-500
Subject(s) - protoporphyrin ix , photosensitizer , chemistry , immunosuppression , sensitization , photodynamic therapy , photobleaching , photosensitivity , delayed hypersensitivity , ratón , immune system , protoporphyrin , immunology , photochemistry , porphyrin , medicine , fluorescence , physics , organic chemistry , quantum mechanics
Photodynamic therapy (PDT) is frequently accompanied by induction of systemic immunosuppression. Photochemical mechanisms underlying this effect are not completely understood. Here, we demonstrate the immunosuppressive activity of photooxidation products of protoporphyrin IX dimethyl ester (PPIX) in a murine model of contact hypersensitivity (CHS) to 2,4‐dinitrofluorobenzene (DNFB). Intravenous injection of the preirradiated solution of PPIX to mice resulted in fluence‐dependent suppression of the CHS. The samples of photodecomposed PPIX with suppressive effect on the CHS contained chlorin‐type products, namely, two isomers of photoprotoporphyrin (pPP1 and pPP2) as main photoproducts. Concentration‐dependent suppression of the CHS was also induced when purified pPP1 or pPP2 were injected to mice intravenously. These purified photoproducts exerted equal immunosuppressive activity. The highest suppression of the CHS was induced when pPP1 was injected 20 h before sensitization with DNFB. The lowest suppression was at its injection time 24 h before challenge. The pPP1‐induced suppression of the CHS was adoptively transferable and was associated with generation of cells with suppressive functions. These suppressor cells inhibited the efferent phase of the CHS. Our results strongly indicate that induction of systemic immunosuppression by PDT with PPIX may proceed through photobleaching of photosensitizer and generation of photoprotoporphyrins, which can affect T cell immunity.