Genetic immunization with LSA3 shielded chimpanzees against falciparum malaria , but we found no information of its use in human beings. T cells were generated. illness in endemic areas . Nevertheless the LSA1 vaccine was not protecting in humans . Genetic immunization with LSA3 safeguarded chimpanzees against falciparum malaria , but we found no info of its use in humans. Recently it has been reported that CelTOS is definitely a protecting antigen both in BALB/c and outbred mice . CelTOS is definitely a micronemal protein secreted by sporozoites during their migration from the skin to the liver . Antibodies generated by CelTOS immunization immobilize sporozoites and inhibit illness of hepatocytes suggesting that protection is at RWJ-445167 least in part antibody mediated . In addition to looking for non-CSP protecting antigens elicited by hyper-immunization of BALB/c mice with IrSp, we performed some experiments to evaluate the protecting potential of selected non-CSP malaria antigens. For this purpose we used adenovirus vectors that are known to induce potent CD8+ T cell-mediated protecting immunity and also antibody reactions against pathogens [24C26]. 2. Materials and methods 2.1. Selection of non-CSP antigens and epitopes We preferentially selected non-CSP antigens with expected transmission sequences from sporozoite and liver stage libraries [27,28]. This is because, in order for the antigens to be identified by effectors T cells, the antigens have to be secreted into the cytoplasm of the infected liver cells [or of neighboring cells] and then processed and offered within the plasma membrane in association of MHC class I . Because the liver stages develop inside a parasitophorous vacuole (PV) and need to traverse the PV membrane to enter the cytoplasm, a higher priority was given to antigens bearing Pexel motifs [29,30]. The effectiveness of T cell acknowledgement should increase when large numbers of peptides derived from non-CSP antigens are present on the surface of the target cells. Therefore we selected preferentially highly transcribed genes [27,28] assuming that the related protein would also become highly RWJ-445167 displayed in the parasite. We made sure that all of the selected genes have orthologs. A total of 34 non-CSP candidate antigens were selected, including a previously reported protecting antigen CelTOS, also named antigen 2 [21,23,31]. From each candidate we chose CD8+ T cell epitopes based on three self-employed computer algorithms that predict binding affinity to MHC class I molecule: http://www-bimas.cit.nih.gov/cgi-bin/molbio/ken_parker_comboform (NIH) http://www.syfpeithi.de/Scripts/MHCServer.dll/EpitopePrediction.htm (SYFPEITHI) http://tools.immuneepitope.org/analyze/html/mhc_binding.html (IEDB) All selected molecules, epitopes and RWJ-445167 predicted binding to Kd are shown in the supplementary Table 1. 2.2. Mice Six- to eight-week-old female BALB/c (H2-Kd) mice were purchased from Taconic (Germantown, NY). BALB/c mice transgenic for CS that were also unable to make antibodies [CSP-Tg/JhT(?/?)] were bred and managed in the NYU School of Medicine. All mice were housed and managed at NYU School of Medicine Animal Facility inside a pathogen free mouse facility relating to institutional recommendations. All animal studies were authorized by the organizations Institutional Animal Care and Use Committee. 2.3. Mosquitoes and IrSp immunization mosquitoes were reared at 27C and 80% moisture under a 12/12 h light/dark cycle, and adults were fed on 10% sucrose remedy. -infected mosquitoes were managed at PDGFRA 25C. Live salivary gland sporozoites were obtained 14 days after the infective meal. The mosquitoes were rinsed in 70% ethanol, washed in DMEM, and the salivary glands eliminated. The glands were softly floor inside a cells homogenizer, centrifuged at 800 rpm for 4 min to remove mosquito debris, and sporozoites were counted inside a haemocytometer and kept on ice until use. For challenge, 104 sporozoites were inoculated into mice intravenously. Prior to immunization, the sporozoites were irradiated (15,000 rads). Mice were immunized intravenously three times with 105 IrSp at 2 weeks intervals. 2.4. ELISPOT assay Multiscreen plates (Millipore, Bedford MA) were coated with 10 g/ml of anti-mouse IFN- (BD Pharmingen). After over night incubation, the wells were washed twice with PBS and then twice with wash Medium (DMEM comprising 10% FCS). After obstructing the wells with wash medium for 6 hours at 37C, splenocytes from immunized mice and synthetic peptides related to the CD8+ T cell epitopes were added to the wells. After incubation at 37C and 5% CO2, for 24C28 h, the plates were extensively 1st washed with PBS, and then with PBS comprising 0.05% of Tween 20 (PBST). The wells were then.
Genetic immunization with LSA3 shielded chimpanzees against falciparum malaria , but we found no information of its use in human beings