Riments in the Graduate School of Gunma University (approved number 12031), and were conducted under the control of the Guidelines for Animal Experiments in the Graduate 
School of Medicine, Gunma University, and the Law (No. 105) and Notification (No. 6) of the Japanese Government.Mice and ParasitesC57BL/6 mice were purchased from Kyudo (Tosu, Japan). Immunoproteasome subunit LMP7-deficient (LMP7-deficient) mice on a C57BL/6 background were established [24] and provided 15857111 by Dr. Fehling HJ (Ulm University, Germany). Age- and sex-matched groups of wild-type (WT) and LMP7-deficient mice were used for the experiments. Blood-stage parasites of Plasmodium yoelii 17XL(PyL) or 17XNL (PyNL) were obtained after fresh 
passage through a donor mouse 2? days after inoculation with a frozen stock. Mice were infected intraperitoneally with 25,000 parasitized pRBCs. pRBCs were separated using a Percoll gradient after removal of leukocytes, as previously described [36]. Briefly, heparinized blood from malaria-infected mice was collected after heart puncture, and passed through a CF11 column to remove white blood cells. The eluent RBC solution was placed onto 58 (v/v) Percoll/PBS and centrifuged, and cells at the interphase or at the bottom were collected as schizont-rich pRBCs or schizont-free RBCs, respectively.Scanning Electron Microscopy (SEM)The surface of RBCs was examined by SEM. RBCs from WT or LMP7-deficient mice were washed with PBS by repeated centrifugation at 1,000 6 g for 10 min to remove contaminating cell debris and were then fixed with 1.5 glutaraldehyde. The specimen was then dehydrated in a series of acetone solutions and finally with amyl acetate. After critical point drying (JCPD2, JEOL), the RBC specimen was coated with gold-palladium for surface conductivity and examined by the scanning mode of the electron microscope (EMASID20 combined with JEM2000EX, JEOL) at 25 kV.StatisticsDifferences between groups were analyzed for statistical significance with unpaired Student t-tests. For survival curves, Kaplan-Meier plots were performed. All of these were performed using Excel software. Probabilities below 0.05 were considered statistically significant.Fluorescence-activated Cell Sorting (FACS) AnalysisThe following antibodies (Abs) were obtained from eBioscience (San Diego, CA) and used to assess cell surface or intracellular expression 25331948 of their respective antigens: allophycocyanin (APC)conjugated MedChemExpress K162 Clavulanic acid potassium salt anti-mouse CD3e (145-2C11), APC-, FITC-, and PEconjugated anti-mouse CD4 (GK1.5), PE-conjugated anti-mouse CD11b (M1/70), FITC-conjugated anti-mouse CD11c (N418), PE-Cy5-conjugated anti-mouse CD40 (1C10), FITC-conjugated anti-mouse CD69 (H1.2F3), APC-conjugated anti-mouse CD80 (16-10A1), APC-conjugated anti-mouse CD86 (GL1), PE-Cy5conjugated anti-mouse I-Ab MHC class II (M5/144.15.2), and PEconjugated anti-mouse IFN-c (XMG1.2). Stained cells were analyzed using FACSCalibur flow cytometer (BD Bioscience,Results LMP7-deficient Mice are Partially Resistant to Infection with Malaria ParasitesWe first infected LMP7-deficient mice with rodent malaria parasites, P. yoelii 17XL (PyL) and P. yoelii 17XNL (PyNL). As previously reported, rapid growth of PyL parasites occurred in WT mice, and all mice infected with PyL succumbed to the infection within 2 weeks (Fig. 1A). Surprisingly, LMP7-deficient mice were partially resistant to the normally lethal infection. More than half of the LMP7-deficient mice tolerated the peak of parasitemia and survived (Fig.Riments in the Graduate School of Gunma University (approved number 12031), and were conducted under the control of the Guidelines for Animal Experiments in the Graduate School of Medicine, Gunma University, and the Law (No. 105) and Notification (No. 6) of the Japanese Government.Mice and ParasitesC57BL/6 mice were purchased from Kyudo (Tosu, Japan). Immunoproteasome subunit LMP7-deficient (LMP7-deficient) mice on a C57BL/6 background were established [24] and provided 15857111 by Dr. Fehling HJ (Ulm University, Germany). Age- and sex-matched groups of wild-type (WT) and LMP7-deficient mice were used for the experiments. Blood-stage parasites of Plasmodium yoelii 17XL(PyL) or 17XNL (PyNL) were obtained after fresh passage through a donor mouse 2? days after inoculation with a frozen stock. Mice were infected intraperitoneally with 25,000 parasitized pRBCs. pRBCs were separated using a Percoll gradient after removal of leukocytes, as previously described [36]. Briefly, heparinized blood from malaria-infected mice was collected after heart puncture, and passed through a CF11 column to remove white blood cells. The eluent RBC solution was placed onto 58 (v/v) Percoll/PBS and centrifuged, and cells at the interphase or at the bottom were collected as schizont-rich pRBCs or schizont-free RBCs, respectively.Scanning Electron Microscopy (SEM)The surface of RBCs was examined by SEM. RBCs from WT or LMP7-deficient mice were washed with PBS by repeated centrifugation at 1,000 6 g for 10 min to remove contaminating cell debris and were then fixed with 1.5 glutaraldehyde. The specimen was then dehydrated in a series of acetone solutions and finally with amyl acetate. After critical point drying (JCPD2, JEOL), the RBC specimen was coated with gold-palladium for surface conductivity and examined by the scanning mode of the electron microscope (EMASID20 combined with JEM2000EX, JEOL) at 25 kV.StatisticsDifferences between groups were analyzed for statistical significance with unpaired Student t-tests. For survival curves, Kaplan-Meier plots were performed. All of these were performed using Excel software. Probabilities below 0.05 were considered statistically significant.Fluorescence-activated Cell Sorting (FACS) AnalysisThe following antibodies (Abs) were obtained from eBioscience (San Diego, CA) and used to assess cell surface or intracellular expression 25331948 of their respective antigens: allophycocyanin (APC)conjugated anti-mouse CD3e (145-2C11), APC-, FITC-, and PEconjugated anti-mouse CD4 (GK1.5), PE-conjugated anti-mouse CD11b (M1/70), FITC-conjugated anti-mouse CD11c (N418), PE-Cy5-conjugated anti-mouse CD40 (1C10), FITC-conjugated anti-mouse CD69 (H1.2F3), APC-conjugated anti-mouse CD80 (16-10A1), APC-conjugated anti-mouse CD86 (GL1), PE-Cy5conjugated anti-mouse I-Ab MHC class II (M5/144.15.2), and PEconjugated anti-mouse IFN-c (XMG1.2). Stained cells were analyzed using FACSCalibur flow cytometer (BD Bioscience,Results LMP7-deficient Mice are Partially Resistant to Infection with Malaria ParasitesWe first infected LMP7-deficient mice with rodent malaria parasites, P. yoelii 17XL (PyL) and P. yoelii 17XNL (PyNL). As previously reported, rapid growth of PyL parasites occurred in WT mice, and all mice infected with PyL succumbed to the infection within 2 weeks (Fig. 1A). Surprisingly, LMP7-deficient mice were partially resistant to the normally lethal infection. More than half of the LMP7-deficient mice tolerated the peak of parasitemia and survived (Fig.
