SUMMARYVisceral leishmaniasis (VL) caused byLeishmaniaspp. is an important vector-borne and largely zoonotic disease. In China, three epidemiological types of VL have been described: anthroponotic VL (AVL), mountain-type zoonotic VL (MT-ZVL), and desert-type ZVL (DT-ZVL). These are transmitted by four different sand fly species:Phlebotomus chinensis,P. longiductus,P. wui, andP. alexandri.In 1951, a detailed survey of VL showed that it was rampant in the vast rural areas west, northwest, and north of the Yangtze River. Control programs were designed and implemented stringently by the government at all administrative levels, resulting in elimination of the disease from most areas of endemicity, except the western and northwestern regions. The control programs consisted of (i) diagnosis and chemotherapy of patients, (ii) identification, isolation, and disposal of infected dogs, and (iii) residual insecticide indoor spraying for vector control. The success of the control programs is attributable to massive and effective mobilization of the general public and health workers to the cause. Nationally, the annual incidence is now very low, i.e., only 0.03/100,000 according to the available 2011 official record. The overwhelming majority of cases are reported from sites of endemicity in the western and northwestern regions. Here, we describe in some depth and breadth the current status of epidemiology, diagnosis, treatment, and prevention of the disease, with particular reference to the control programs. Pertinent information has been assembled from scattered literature of the past decades in different languages that are not readily accessible to the scientific community. The information provided constitutes an integral part of our knowledge on leishmaniasis in the global context and will be of special value to those interested in control programs.

Mouse models differ considerably from humans with regard to clinical symptoms of toxoplasmosis caused by Toxoplasma gondii and, by comparison, the rat model is more representative of this disease in humans. In the present study, we found that different strains of adult and newborn rats (Lewis, Wistar, Sprague Dawley, Brown Norway and Fischer 344) exhibited remarkable variation in the number of brain cysts following inoculation with the T.gondii Prugniaud strain. In adult rats, large numbers of cysts (1231 ± 165.6) were observed in Fischer 344, but none in the other four. This situation was different in newborn rats aged from 5 to 20 days old. All Fischer 344 and Brown Norway newborns were cyst-positive while cyst-positive infection in Sprague Dawley neonates ranged from 54.5% to 60% depending on their age at infection. In Wistar and Lewis rat neonates, however, cyst-positivity rates of 0-42.9% and 0-25% were found respectively. To investigate whether rat strain differences in infectivity could be related to inherent strain and genetic differences in the host immune response, we correlated our data with previously reported strain differences in iNOS/Arginase ratio in adult rats and found them to be linked. These results show that interactions between host genetic background and age of rat influence T.gondii infection.

Background Mesenchymal stromal cells (MSCs) are a heterogeneous cell population endowed with multi-lineage differentiation potential and extensive immunomodulatory properties. MSCs have been successfully used for prevention and treatment of immune disorders such as graft-versus-host disease. Emerging preclinical studies suggest that MSCs might also protect against infectious challenge. Aims This study aimed to rule out the potential mechanism of human MSCs against Toxoplasma gondii (T. gondii). Methods Human bone marrow-derived MSCs (hMSCs) were pretreated for 24h with a series of concentrations of IFN-γ and then infected with T. gondii strains of variant virulences (virulent RH and avirulent ME49). RNA-seq and westernblots were used to analyze gene and protein expression patterns of hMSCs in IFN-γ-stimulated and unstimulated conditions. The intracellular parasites (with fluorescence labeled) were counted microscopically at multiple time points postinfection. The short hairpin RNA (shRNA) expression was used to generate RNAi of GBP-1, GBP-2 and GBP-5. Results Human MSCs stimulated with IFN-γ were capable to inhibit the growth of T. gondii (eg: at IFN-γ 10ng/ml, the inhibition rates are 26.5% (RH) and 37.5% (ME49) 12hr postinfection) in a dose-dependent manner. Compared with the unstimulated MSCs (controls), IFN-γ treatment at 5, 10, 20ng/ml inhibited T. gondii (ME49) growth by percent of 27.1±7.9, 37.5±6.2, 47.0±7.6 (mean±SD, n=4) 12 hr postinfection and the inhibition rates are 54.5±2.1%, 62.5±4.9% and 78.5±2.1 at 24 hr postinfection, respectively. After 48 hr postinfection, the ratio between parasites per parasitophorous vacuole (PV) containing rosettes and single paraites in IFN-γ-stimulated MSCs was significantly reduced compared with that in the unstimulated MSCs (p<0.01, p<0.01, p<0.001 for ME49 at IFN-γ 5, 10, 20ng/ml, respectively). Furthermore, There was no significant effect of conditioned medium (CM) from IFN-γ-stimulated MSCs on T. gondii growth in comparison with CM from unstimulated MSCs (p=0.74 for RH and p=0.69 for ME49). We observed that the resistance in hMSCs does not depend on IDO (p=0.85 for RH and p=0.79 for ME49). RNA-seq data showed that IFN-γ-inducible p65 guanylate-binding proteins (GBPs) might play pivotal roles in the inhibition of T. gondii growth. Reads per kilobase-pairs per million (RPKM) mean values of GBP1, 2, 5 in IFN-γ-stimulated MSCs are 1093.3, 443.3, 348.2, respectively. By RNAi knockdown, the results showed that silencing of GBP1 (but not GBP2, GBP5) in hMSCs resulted in recovery of T. gondii growth inhibition at 12 hr and 24 hr postinfection (p<0.05 and p<0.001 for ME49). Conclusion: Human MSCs pre-stimulated with IFN-γ inhibited the growth of T. gondii in a dose-dependent manner via up-regulation of GBP-1 expression. Disclosures Liu: the project of the Zhujiang Science & Technology Star of Guangzhou city (2013027): Research Funding; the Technology Plan of Guangdong Province of China (2012B031800403): Research Funding; the project of health collaborative innovation of Guangzhou city (201400000003-4, 201400000003-1): Research Funding; Natural Science Foundation of Guangdong Province (S2012010009299): Research Funding; National Public Health Grand Research Foundation (201202017): Research Funding; National High Technology Research and Development Program of China (863 Program) (2011AA020105): Research Funding; National Natural Science Foundation of China (81270647, 81300445, 81200388): Research Funding.