A toxicology study of Csf2ra complementation and pulmonary macrophage transplantation therapy of hereditary PAP in mice.

Pulmonary macrophage transplantation (PMT) is a gene and cell transplantation approach in development as therapy for hereditary pulmonary alveolar proteinosis (hPAP), a surfactant accumulation disorder caused by mutations in CSF2RA/B (and murine homologs). We conducted a toxicology study of PMT of Csf2ra gene-corrected macrophages (mGM-Rα+Mϕs) or saline-control intervention in Csf2raKO or wild-type (WT) mice including single ascending dose and repeat ascending dose studies evaluating safety, tolerability, pharmacokinetics, and pharmacodynamics. Lentiviral-mediated Csf2ra cDNA transfer restored GM-CSF signaling in mGM-Rα+Mϕs. Following PMT, mGM-Rα+Mϕs engrafted, remained within the lungs, and did not undergo uncontrolled proliferation or result in bronchospasm, pulmonary function abnormalities, pulmonary or systemic inflammation, anti-transgene product antibodies, or pulmonary fibrosis. Aggressive male fighting caused a similarly low rate of serious adverse events in saline- and PMT-treated mice. Transient, minor pulmonary neutrophilia and exacerbation of pre-existing hPAP-related lymphocytosis were observed 14 days after PMT of the safety margin dose but not the target dose (5,000,000 or 500,000 mGM-Rα+Mϕs, respectively) and only in Csf2raKO mice but not in WT mice. PMT reduced lung disease severity in Csf2raKO mice. Results indicate PMT of mGM-Rα+Mϕs was safe, well tolerated, and therapeutically efficacious in Csf2raKO mice, and established a no adverse effect level and 10-fold safety margin.

Spatial distribution and risk factors of Schistosoma haematobium and hookworm infections among schoolchildren in Kwale, Kenya.

BACKGROUND: Large-scale schistosomiasis control programs are implemented in regions with diverse social and economic environments. A key epidemiological feature of schistosomiasis is its small-scale heterogeneity. Locally profiling disease dynamics including risk factors associated with its transmission is essential for designing appropriate control programs. To determine spatial distribution of schistosomiasis and its drivers, we examined schoolchildren in Kwale, Kenya. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a cross-sectional study of 368 schoolchildren from six primary schools. Soil-transmitted helminths and Schistosoma mansoni eggs in stool were evaluated by the Kato-Katz method. We measured the intensity of Schistosoma haematobium infection by urine filtration. The geometrical mean intensity of S. haematobium was 3.1 eggs/10 ml urine (school range, 1.4-9.2). The hookworm geometric mean intensity was 3.2 eggs/g feces (school range, 0-17.4). Heterogeneity in the intensity of S. haematobium and hookworm infections was evident in the study area. To identify factors associated with the intensity of helminth infections, we utilized negative binomial generalized linear mixed models. The intensity of S. haematobium infection was associated with religion and socioeconomic status (SES), while that of hookworm infection was related to SES, sex, distance to river and history of anthelmintic treatment. CONCLUSIONS/SIGNIFICANCE: Both S. haematobium and hookworm infections showed micro-geographical heterogeneities in this Kwale community. To confirm and explain our observation of high S. haematobium risk among Muslims, further extensive investigations are necessary. The observed small scale clustering of the S. haematobium and hookworm infections might imply less uniform strategies even at finer scale for efficient utilization of limited resources.

IL-17A contributes to reducing IFN-γ/IL-4 ratio and persistence of Entamoeba histolytica during intestinal amebiasis.

Amebiasis is an infectious disease caused by Entamoeba histolytica, an anaerobic protozoan parasite, and is a major public health problem worldwide, particularly in areas with inadequate sanitation and poor hygiene. Th1 responses, represented by interferon gamma (IFN-γ), play a protective role by clearing the amebae from the gut, whereas Th2 responses are responsible for chronic infection. Th17 responses preconditioned by vaccination or by modulating the intestinal microbiome protect mice from the settlement of E. histolytica. However, the role of interleukin-17A (IL-17A), which is upregulated during the natural course of intestinal amebiasis, has not been clarified. The aim of this study was to investigate the role of IL-17A during intestinal amebiasis in a mouse model. IL-17A knockout and wild-type CBA/J mice were challenged intracecally with 2×106E. histolytica trophozoites, and their infection, pathology, and immune responses were monitored. Neither the initial settlement of E. histolytica nor the inflammation of the cecum was affected by the absence of IL-17A for week 1, but the infection rate and parasite burden declined in a late stage of infection, accompanied by an increased IFN-γ/IL-4 ratio. Therefore, IL-17A contributes to the persistence of E. histolytica and modulates the immune response, including the IFN-γ/IL-4 ratio, which may be responsible for the reduction of the parasite burden in the IL-17A knockout mice during the chronic phase of intestinal amebiasis.

Tandem repeat recombinant proteins as potential antigens for the sero-diagnosis of Schistosoma mansoni infection.

The diagnosis of schistosome infection, followed by effective treatment and/or mass drug administration, is crucial to reduce the disease burden. Suitable diagnostic tests and field-applicable tools are required to sustain schistosomiasis control programs. We therefore assessed the potential of tandem repeat (TR) proteins for sero-diagnosis of Schistosoma mansoni infection using an experimental mouse model. TR genes in the genome of S. mansoni were searched in silico and 7 candidates, named SmTR1, 3, 8, 9, 10, 11 and 15, were selected. Total RNA was extracted from S. mansoni adult worms and eggs. Target TR genes were amplified, cloned, and the proteins were expressed in Escherichia coli competent cells. Female BALB/c mice were infected with 100 S. mansoni cercariae and sera were collected each week post-infection for 18 weeks. The levels of IgG antibodies to SmTR antigens were compared to those to soluble egg antigen (SEA) and to soluble worm antigen preparation (SWAP). Sera of infected mice reacted to all the antigens whereas those of naïve mice did not. IgG responses to SmTR1, 3, 9 and 10 were detected at the early stage of infection. Interestingly, antibodies reacting to SmTR3, 9, 10 and 15 dramatically decreased 4 weeks after treatment with praziquantel, while those against SEA and SWAP remained elevated. Our study suggests that TR proteins, especially SmTR10, may be suitable antigens for sero-diagnosis of infection by S. mansoni and are potential markers for monitoring and surveillance of schistosomiasis, including re-infection after treatment with praziquantel.