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Teresa Broquetas,1,2 José A Carrión1– 3 1Liver Section, Gastroenterology Department, Hospital del Mar, Barcelona, Spain; 2IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain; 3Department of Medicine and Life Sciences, Universitat Pompeu Fabra, Barcelona, SpainCorrespondence: José A Carrión, Liver Section, Gastroenterology Department, Hospital del Mar, 25-29 Passeig Marítim, Barcelona, 08003, Spain, Tel +34 93 2483220, Fax +34 93 2218644, Email jcarrion@psmar.catAbstract: The hepatitis B virus (HBV) infection remains a global public health problem. This review presents updated recommendations for the optimal current treatment of choice with nucleos(t)ide analogues (NA). Current clinical practice guidelines on the management of chronic hepatitis B (CHB) by the Asian Pacific Association for the Study of the Liver, the European Association for the Study of the Liver and the American Association for the Study of Liver Diseases have been considered. Patients with chronic HBV infection are at increased risk of liver disease progression to cirrhosis and hepatocellular carcinoma (HCC) development. The main goal of therapy is to improve survival preventing disease progression and HCC. The induction of long-term suppression of HBV replication represents the main endpoint of current treatment strategies, while hepatitis B surface antigen (HBsAg) loss is the optimal endpoint. The typical indication for treatment requires elevated HBV desoxyribonucleic acid (DNA), elevated alanine aminotransferase and/or at least moderate histological lesions, while all cirrhotic patients with detectable HBV DNA should be treated. The long-term administration of a potent NA with high barrier to resistance, ie, entecavir, tenofovir disoproxil fumarate or tenofovir alafenamide, represents the treatment of choice. However, HBsAg seroclearance is anecdotal with NA. Treated patients should be monitored for therapy response, adherence, risk of disease progression, and risk of HCC development. This review aims to assess the evolving trends on the potent NA and the new perspectives on finite therapy.Keywords: antiviral therapy, efficacy, HBsAg loss, kinetics, treatment cessation

Abstract Leishmania major is the major cause of cutaneous leishmaniosis (CL) outside of the Americas. In the present study we have cloned six Leishmania genes (H2A, H2B, H3, H4, A2 and HSP70) into the eukaryotic expression vector pCMVβ-m2a, resulting in pCMV-HISA70m2A, which encodes all six pathoantigenic proteins as a single polyprotein. This expression plasmid has been evaluated as a novel vaccine candidate in the BALB/c mouse model of CL. The DNA vaccine shifted the immune response normally induced by L. major infection away from a Th2-specific pathway to one of basal susceptibility. Immunization with pCMV-HISA70m2A dramatically reduced footpad lesions and lymph node parasite burdens relative to infected control mice. Complete absence of visceral parasite burden was observed in all 12 immunized animals but not in any of the 24 control mice. Moreover, vaccinated mice produced large amounts of IFN-γ, IL-17 and NO at 7 weeks post-infection (pi), and they showed lower arginase activity at the site of infection, lower IL-4 production and a weaker humoral immune response than infected control mice. Taken together, these results demonstrate the ability of the HISA70 vaccine to shift the murine immune response to L. major infection away from an undesirable, Th2-specific pathway to a less susceptible-like pathway involving Th1 and Th17 cytokine profiles.

Abstract Background Visceral leishmaniasis is the most severe form of leishmaniasis and no effective vaccine exists. The use of live attenuated vaccines is emerging as a promising vaccination strategy. Results In this study, we tested the ability of a Leishmania infantum deletion mutant, lacking both HSP70-II alleles (ΔHSP70-II), to provide protection against Leishmania infection in the L. major-BALB/c infection model. Administration of the mutant line by either intraperitoneal, intravenous or subcutaneous route invariably leads to the production of high levels of NO and the development in mice of type 1 immune responses, as determined by analysis of anti-Leishmania IgG subclasses. In addition, we have shown that ΔHSP70-II would be a safe live vaccine as immunodeficient SCID mice, and hamsters (Mesocricetus auratus), infected with mutant parasites did not develop any sign of pathology. Conclusions The results suggest that the ΔHSP70-II mutant is a promising and safe vaccine, but further studies in more appropriate animal models (hamsters and dogs) are needed to appraise whether this attenuate mutant would be useful as vaccine against visceral leishmaniasis.

Abstract Several animal models have been established to study visceral leishmaniosis (VL), a worldwide vector-borne disease affecting humans and domestic animals that constitutes a serious public health problem. BALB/c mice and Syrian hamsters are the most widely used experimental models. In this paper, we summarize the advantages and disadvantages of these two experimental models and discuss the results obtained using these models in different studies of VL. Studies using the BALB/c mouse model have underscored differences between the liver and spleen in the course of VL, indicating that pathological evaluation of the visceral organs is essential for understanding the immune mechanisms induced by Leishmania infantum infection. The main goal of this review is to collate the relevant literature on Leishmania pathogenesis into a sequence of events, providing a schematic view of the main components of adaptive and innate immunity in the liver and spleen after experimental infection with L. infantum or L. donovani. This review also presents several viewpoints and reflections about some controversial aspects of Leishmania research, including the choice of experimental model, route of administration, inoculum size and the relevance of pathology (intimately linked to parasite persistence): a thorough understanding of which is essential for future VL research and the successful development of efficient control strategies for Leishmania spp.