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Fig. 4 | Parasites & Vectors

Fig. 4

From: New "light" for one-world approach toward safe and effective control of animal diseases and insect vectors from leishmaniac perspectives

Fig. 4

Safety and efficacy evaluations of PDT-inactivated Leishmania prepared under different conditions for immuno-prophylaxis and therapy. Horizontal: [1] and [2], Single PS-sensitization with ALA (+ALA) for uroporphyrin (URO) or Si-PC-loading (PC) followed by single photo-inactivation with blue or red light illumination for generation of cytotoxic 1O2 (Symbol as shown), respectively [6, 7, 1012]; [3], Double PS-sensitization/double photo-inactivation using a combination of [1] and [2] conditions [35]; [45], Singly or doubly PDT-inactivated Leishmania from [1-3B] stored frozen at −20 °C and lyophilized, respectively. See legend to Fig. 2 for other abbreviations used. Vertical: [A–B], PS-sensitization/photo-inactivation of Leishmania under the conditions as described in [1–5]. [C], Safety evaluations of the samples examined by microscopic observation for promastigote flagellar motility, for growth after inoculation into culture medium for 2 weeks, and lesion development after injection to BALB/c mouse ear dermis or tail base for ~60 days; [D], Efficacy evaluation in vitro and/or in vivo briefly summarized from published, on-going or planned studies. See text for [1D] and [2D] efficacy. Experimental-in-brief: see [25] for [1D in vivo]; see [12] for [2D in vitro]; [2D in vivo]: Groups of BL57 mice (~30 gm, 15/group) were immunized i.d. with 106 photo-inactivated OVA transfectants/10 ul PBS/ear for 3 times 1-week apart. Control groups were simultaneously and similarly immunized with un-treated, PC-sensitized, light-exposed, freeze-thawed OVA-transfectants, and 1 ug OVA. Splenic cells were collected from four mice from each group 2-weeks after 1–3 immunization for in vitro activation with OVA CD4- and CD8-specific peptides for ~4 days. Proliferation of CFSE-labeled lymphocytes was assayed flow cytometrically, providing the results briefly described in the text; [3D in vivo]: Female BLAB/c mice (~30 g) were immunized exactly as described for [2D in vivo], except that doubly PS-sensitized Leishmania were used. Controls included 6 groups using untreated, single PS-sensitized, light-exposed samples. Day 3 after immunization, photo-inactivation of Leishmania was carried out in situ at ~5 J/cm2 using LumaCare LC-122 white light probe. Mice were each challenged at the tailbase with 107 parasites. Lesion size was measured weekly in all groups. Experiments were terminated after ~10 weeks when parasite loads were determined by limiting dilution method. Preliminary results obtained were briefly described in the text. Abbreviations: CanVL, canine leishmaniasis; Li, Leishmania infantum; Lt, Leishmania tropica

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