Protective efficacy of lambdacyhalothrin-impregnated bednets against Phlebotomus orientalis, the vector of visceral leishmaniasis in Sudan

1999 ◽  
Vol 13 (3) ◽  
pp. 310-314 ◽  
Author(s):  
D. A. Elnaiem ◽  
A. M. Elnahas ◽  
M. A. Aboud
Keyword(s):  
Visceral Leishmaniasis ◽  
Protective Efficacy ◽  
Phlebotomus Orientalis

Characterization of breeding sites of Phlebotomus orientalis – The vector of visceral leishmaniasis in northwestern Ethiopia

Acta Tropica ◽  
2014 ◽  
Vol 139 ◽  
pp. 5-14 ◽  
Author(s):  
Aviad Moncaz ◽  
Oscar Kirstein ◽  
Araya Gebresellassie ◽  
Wossenseged Lemma ◽  
Solomon Yared ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Breeding Sites ◽  
Phlebotomus Orientalis

scholarly journals gp63 in Stable Cationic Liposomes Confers Sustained Vaccine Immunity to Susceptible BALB/c Mice Infected with Leishmania donovani

2008 ◽  
Vol 76 (3) ◽  
pp. 1003-1015 ◽  
Author(s):  
Swati Bhowmick ◽  
Rajesh Ravindran ◽  
Nahid Ali
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Donovani ◽  
Protective Efficacy ◽  
Cationic Liposomes ◽  
Interleukin 4 ◽  
Th2 Response ◽  
Parasitic Burden ◽  
Ifn Γ ◽  
Dose Dependent

ABSTRACT Visceral leishmaniasis is deadly if not treated, and development of a vaccine with long-term immunity remains a challenge. In this study, we showed that cationic distearoyl phosphatidylcholine (DSPC) liposomes, when used as vaccine adjuvant with the immunodominant 63-kDa glycoprotein (gp63) of Leishmania donovani promastigotes, induced significant protection against progressive visceral leishmaniasis in susceptible BALB/c mice. gp63 used without adjuvant elicited partial protection but in association with liposomes exhibited marked resistance in both the livers and spleens of the mice challenged 10 days after the last vaccination. The protective efficacy of liposomal gp63 vaccination was dose dependent, with 2.5 μg of protein showing optimal protection. The immunity conferred by this vaccine formulation was durable, as mice challenged 12 weeks after immunization were still protected, and the infection was controlled for at least 3 months postchallenge. Production of gamma interferon (IFN-γ) and interleukin-4 (IL-4) by splenic T cells, and of serum immunoglobulin G1 (IgG1) and IgG2a following immunization, suggested that a mixed Th1/Th2 response had been induced following immunization. However, control of disease progression and parasitic burden in mice vaccinated with gp63 in cationic DSPC liposomes was associated with enhancement of antigen-specific IFN-γ and downregulation of IL-4, demonstrating a Th1 bias. Long-term immunity elicited by this vaccine corresponded to, in addition to the presence of antigen-specific Th1, CD8+ T-cell responses. Our results demonstrated that stable cationic liposomes containing gp63 acted as a potent adjuvant for protein antigen to induce long-term protection against L. donovani that represents an alternative to DNA vaccination.

scholarly journals Host-feeding preference of Phlebotomus orientalis (Diptera: Psychodidae) in an endemic focus of visceral leishmaniasis in northern Ethiopia

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Araya Gebresilassie ◽  
Ibrahim Abbasi ◽  
Essayas Aklilu ◽  
Solomon Yared ◽  
Oscar David Kirstein ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Feeding Preference ◽  
Northern Ethiopia ◽  
Host Feeding ◽  
Endemic Focus ◽  
Phlebotomus Orientalis

scholarly journals Protective Efficacy in a Hamster Model of a Multivalent Vaccine for Human Visceral Leishmaniasis (MuLeVaClin) Consisting of the KMP11, LEISH-F3+, and LJL143 Antigens in Virosomes, Plus GLA-SE Adjuvant

2021 ◽  
Vol 9 (11) ◽  
pp. 2253
Author(s):  
Laura Fernández ◽  
Jose Carlos Solana ◽  
Carmen Sánchez ◽  
Mª Ángeles Jiménez ◽  
Jose M. Requena ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Process Development ◽  
Protective Efficacy ◽  
Humoral Response ◽  
Cost Effective ◽  
Salivary Protein ◽  
Sand Fly ◽  
Vaccine Formulation ◽  
Hamster Model ◽  
Nucleoside Hydrolase

Visceral leishmaniasis (VL) is the most severe clinical form of leishmaniasis, fatal if untreated. Vaccination is the most cost-effective approach to disease control; however, to date, no vaccines against human VL have been made available. This work examines the efficacy of a novel vaccine consisting of the Leishmania membrane protein KMP11, LEISH-F3+ (a recombinant fusion protein, composed of epitopes of the parasite proteins nucleoside hydrolase, sterol-24-c-methyltransferase, and cysteine protease B), and the sand fly salivary protein LJL143, in two dose ratios. The inclusion of the TLR4 agonist GLA-SE as an adjuvant, and the use of virosomes (VS) as a delivery system, are also examined. In a hamster model of VL, the vaccine elicited antigen-specific immune responses prior to infection with Leishmania infantum. Of note, the responses were greater when higher doses of KMP11 and LEISH-F3+ proteins were administered along with the GLA-SE adjuvant and/or when delivered within VS. Remarkably, hamsters immunized with the complete combination (i.e., all antigens in VS + GLA-SE) showed significantly lower parasite burdens in the spleen compared to those in control animals. This protection was underpinned by a more intense, specific humoral response against the KMP11, LEISH-F3+, and LJL143 antigens in vaccinated animals, but a significantly less intense antibody response to the pool of soluble Leishmania antigens (SLA). Overall, these results indicate that this innovative vaccine formulation confers protection against L. infantum infection, supporting the advancement of the vaccine formulation into process development and manufacturing and the conduction of toxicity studies towards future phase I human clinical trials.

scholarly journals Preclinical validation of a second generation leishmanization vaccine against vector transmitted fatal visceral leishmaniasis

2020 ◽  
Author(s):  
Subir Karmakar ◽  
Nevien Ismail ◽  
Fabiano Oliveira ◽  
James Oristian ◽  
Wen Wei Zhang ◽  
...  
Keyword(s):  
Immune Response ◽  
Visceral Leishmaniasis ◽  
Leishmania Donovani ◽  
Leishmania Major ◽  
Protective Efficacy ◽  
Sand Fly ◽  
Endemic Region ◽  
Cytokines And Chemokines ◽  
Human Leishmaniasis ◽  
Strong Candidate

AbstractVisceral Leishmaniasis (VL) is fatal if untreated. There is no licensed vaccine available against human leishmaniasis. We recently demonstrated protection in mice against L. major infection using a CRISPR genome edited attenuated Leishmania major strain (LmCen−/−). Here, as a pre-clinical step, we evaluated the protective efficacy of LmCen−/− against VL induced by sand fly transmitted Leishmania donovani in hamsters. Intradermal immunization of hamsters with LmCen−/− did not develop any lesion; while still priming a pro-inflammatory immune response. When challenged with L. donovani either by intradermal needle injection or by infected sand flies, LmCen−/−-immunized hamsters were protected, not showing spleen or liver pathology averting VL fatality compared to control animals. Spleen cells from LmCen−/− immunized and infected sand fly challenged hamsters produced significantly higher Th1-associated cytokines and chemokines including IFN-γ and TNF-α, and significantly reduced expression of the anti-inflammatory cytokines IL-10 and IL-21, compared to non-immunized challenged animals. We further developed a GLP-grade LmCen−/− which showed equal protection as laboratory-grade LmCen−/− parasites in hamsters. Importantly, GLP-grade LmCen−/− parasites also induced a proinflammatory immune response in the PBMCs isolated from healthy people living in non-endemic and endemic for VL as well as cured VL people living in endemic region. Together, this study demonstrates that the LmCen−/− parasites are safe and efficacious against VL and it is a strong candidate vaccine to be tested in a human clinical trial.

scholarly journals Investigation of the antigenicity and protective efficacy of Leishmania promastigote membrane antigens in search of potential diagnostic and vaccine candidates against visceral leishmaniasis

2019 ◽  
Author(s):  
Sarfaraz Ahmad Ejazi ◽  
Smriti Ghosh ◽  
Anirban Bhattacharyya ◽  
Mohd Kamran ◽  
Sonali Das ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Vaccine Candidate ◽  
Protective Efficacy ◽  
Indian Subcontinent ◽  
Murine Models ◽  
Past Infection ◽  
Vaccine Candidates ◽  
Membrane Antigens ◽  
Human Use ◽  
New Biomarkers

Abstract BackgroundVisceral leishmaniasis (VL), a parasitic disease causes serious medical consequences if treatment is delayed. Despite a decline in the number of VL cases in the Indian Subcontinent, commencement of the disease in newer areas continues to be a major concern. Although serological diagnosis mainly by immunochromatographic tests has been found to be effective, test for cure in different phases of treatment is still desired. Even though good prophylactic response has been obtained in murine models by a number of vaccine candidates, few have been proposed for human use. MethodsIn this study, nine antigenic components (31, 34, 36, 45, 51, 63, 72, 91 and 97 kDa) of Leishmania promastigote membrane antigens, LAg, were electroeluted and evaluated through ELISA to diagnose and distinguish active VL from one month cured and six month past infection. Further, to investigate the immunogenicity of electroeluted proteins, humans PBMCs of cured VL patients were stimulated with 31, 34, 51, 63, 72, and 91 kDa proteins.ResultsWe found that 34 and 51 kDa fractions show 100% sensitivity and specificity with healthy controls and other diseases. After six months post treatment antibodies to 72 and 91 kDa antigens show a significant decline to almost normal levels. This suggests that 34 and 51 kDa are efficient in diagnosis whereas 72 and 91 kDa may be used to monitor treatment outcome. In another study, 51 and 63 kDa proteins demonstrated maximum ability for up-regulate IFN-g and IL-12 with minimum induction of IL-10 and TGF-β. The results indicating that 51 and 63 kDa proteins could be strong candidates for human immunization against VL. In contrast, 34 and 91 kDa demonstrated a reverse profile and may not be a good vaccine candidate. ConclusionsThe present study accounts our search for new biomarkers for tests of clinical cure as well as effective immunoprophylactic candidates for VL vaccination.

scholarly journals Investigation of the antigenicity and protective efficacy of Leishmania promastigote membrane antigens in search of potential diagnostic and vaccine candidates against visceral leishmaniasis

2020 ◽  
Author(s):  
Sarfaraz Ahmad Ejazi ◽  
Smriti Ghosh ◽  
Anirban Bhattacharyya ◽  
Mohd Kamran ◽  
Sonali Das ◽  
...  
Keyword(s):  
Immune Response ◽  
Visceral Leishmaniasis ◽  
Protective Efficacy ◽  
Indian Subcontinent ◽  
Past Infection ◽  
Vaccine Candidates ◽  
Cell Mediated Immune Response ◽  
Membrane Antigens ◽  
Human Use

Abstract Background: Visceral leishmaniasis (VL), a parasitic disease causes serious medical consequences if treatment is delayed. Despite a decline in the number of VL cases in the Indian Subcontinent, the commencement of the disease in newer areas continues to be a major concern. Although serological diagnosis mainly by immunochromatographic tests has been found to be effective, test for cure in different phases of treatment is still desired. Even though a good prophylactic response has been obtained in murine models by a number of vaccine candidates, few have been proposed for human use. Methods: In this study, nine antigenic components (31, 34, 36, 45, 51, 63, 72, 91 and 97 kDa) of Leishmania promastigote membrane antigens, LAg, were electroeluted and evaluated through ELISA to diagnose and distinguish active VL from one month cured and six month past infection. Further, to investigate the immunogenicity of electroeluted proteins, human PBMCs of cured VL patients were stimulated with 31, 34, 51, 63, 72, and 91 kDa proteins. Results: We found that 34 and 51 kDa proteins show 100% sensitivity and specificity with healthy controls and other diseases. After six months post treatment, antibodies to 72 and 91 kDa antigens show a significant decline to almost normal levels. This suggests that 34 and 51 kDa are efficient in diagnosis whereas 72 and 91 kDa may be used to monitor treatment outcome. In another study, 51 and 63 kDa proteins demonstrated maximum ability for up-regulate IFN-g and IL-12 with minimum induction of IL-10 and TGF-β. The results indicating that 51 and 63 kDa proteins could be strong candidates for human immunization against VL. In contrast, 34 and 91 kDa demonstrated a reverse profile and may not be a good vaccine candidate. Conclusions: The preliminary data obtained in this study proposes the potential of some of the antigens in Leishmania diagnosis and for test of cure. Additionally, some antigens demonstrated good immunoprophylactic cytokine production through T cell mediated immune response suggesting future vaccine candidates for VL. However, further studies are necessary to explore these antigens in diagnosis and to access long-term immune response.

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