Leishmania infantum is the causative agent of infantile visceral leishmaniasis in the Mediterranean region of the Old World and in Latin America, where it has been called Leishmania chagasi. It is also an unusual cause of cutaneous leishmaniasis. Wild canids and domestic dogs are the natural reservoir of this organism. L. infantum is closely-related to L. donovani and some authors believe that these two species are so close as to actually be subspecies of each other, however phylogenetic analyses can distinguish between these two groups (Wiki: Leishmania infantum).
4. Microbial Pathogenesis
The parasites are transmitted by the bite of sandflies and the infecting promastigotes differentiate into and replicate as amastigotes within macrophages in the mammalian host (Goto et al., 2007).
5. Host Ranges and Animal Models
Wild canids and domestic dogs are the natural reservoir of L. infantum, and the parasite is vectored by sandflies which pass on infection when they bite mammals including humans (Goto et al., 2007).
6. Host Protective Immunity
In common with other intracellular pathogens, cellular immune responses are critical for protection against leishmaniasis. Th1 immune responses play an important role in mediating protection against Leishmania, including roles for CD4+ and CD8+ T cells, IFN-γ, IL-12, TNF-α and NO, whereas inhibitory effects have been reported for IL-10 and TGF-β (Goto et al., 2007).
Molecule Role Annotation :
Following infection with L. infantum promastigotes, five out of eight beagle dogs immunized with H1 Montanide remained free of clinical signs, compared to two out of eight dogs in the control group. The results demonstrate that H1 antigens with Montanide were able to induce partial protection against canine leishmaniasis, even under extreme experimental challenge conditions (Moreno et al., 2007).
Molecule Role Annotation :
Following infection with L. infantum promastigotes, four out of eight beagle dogs immunized with HASPB1 Montanide remained free of clinical signs, compared to two out of eight dogs in the control group. The results demonstrate that HASPB1 antigens with Montanide were able to induce partial protection against canine leishmaniasis, even under extreme experimental challenge conditions (Moreno et al., 2007).
Molecule Role Annotation :
A Leishmania infantum deletion mutant of HSP70-II gene is attenuated and provides protection against Leishmania infection in the L. major-BALB/c infection model. Also, DeltaHSP70-II is a safe live vaccine as immunodeficient SCID mice, and hamsters, infected with mutant parasites did not develp any sign of pathology (Carrion et al., 2011).
Molecule Role Annotation :
Study examined the immunogenic properties of the Leishmania infantum acidic ribosomal protein P0 (LiP0) in the BALB/c mouse model. When mice were immunized with pcDNA3-LiP0, noticeable protection against L. major infection was achieved (Iborra et al., 2003).
>CAM69515.1 activated protein kinase c receptor (LACK); p36 LACK protein [Leishmania infantum]
MNYEGHLKGHRGWVTSLACPQQAGSYIKVVSTSRDGTAISWKANPDRHSVDSDYGLPSHRLEGHTGFVSC
VSLAHATDYALTASWDRSIRMWDLRNGQCQRKFLKHTKDVLAVAFSPDDRLIVSAGRDNVIRVWNVAGEC
MHEFLRDGHEDWVSSICFSPSLEHPIVVSGSWDNTIKVWNVNGGKCERTLKGHSNYVSTVTVSPDGSLCA
SGGKDGAALLWDLSTGEQLFKINVESPINQIAFSPNRFWMCVATERSLSVYDLESKAVIAELTPDGAKPS
ECISIAWSADGNTLYSGHKDNLIRVWSISDAE
Molecule Role :
Protective antigen
Molecule Role Annotation :
BALB/c mice immunized with a DNA vector expressing p36/LACK of Leishmania infantum followed by a booster with VVp36/LACK induced significant protection against Leishmania major infection (Gonzalo et al., 2001).
Molecule Role Annotation :
Upon challenge with L. infantum, C57BL/6 mice immunized with SMT formulated in MPL-SE adjuvant showed significantly lower parasite burdens in both spleens and livers compared with non-immunized mice or mice injected with adjuvant alone (Goto et al., 2007).
Recombinant L. tarentolae expressing the L. donovani A2 antigen along with cysteine proteinases (CPA and CPB without its unusual C-terminal extension (CPB(-CTE))) as a tri-fusion gene (Saljoughian et al., 2013).
g. Immunization Route
Intramuscular injection (i.m.)
h.
Mouse Response
Vaccination Protocol:
Group 1 (DNA cSLN/Live) immunized with pcDNA-A2-CPA-CPB-CTE-cSLN (50 µg of pcDNA-A2-CPA-CPB-CTE formulated by cSLN nanoparticles as a chemical delivery as previously described [59] as a prime and with 2×10^7 recombinant L. tarentolae A2-CPA-CPB-CTE as a boost; group 2 (L. tarentolae Live A2-CPA-CPB-CTE/L. tarentolae Live A2-CPA-CPB-CTE) vaccinated with 2×10^7 recombinant L. tarentolae-A2-CPA-CPB-CTE as prime and boost; group 3 (PBS as a control); group 4 [(empty vector pcDNA-cSLN (prime)/Live L. tarentolae wild type (boost) as a control)]; and group 5 (L. tarentolae Live/L. tarentolae Live) vaccinated with 2×10^7 L. tarentolae wild type as prime and boost and used as a control. All groups were immunized via footpad (Saljoughian et al., 2013).
Vaccine Immune Response Type:
VO_0003057
Challenge Protocol:
Three weeks after the last immunization, all animals were challenged with 10^7 stationary phase L. infantum promastigotes by lateral tail vein (Saljoughian et al., 2013).
Efficacy:
Our results showed that immunization with both prime-boost A2-CPA-CPB(-CTE)-recombinant L. tarentolae protects BALB/c mice against L. infantum challenge (Saljoughian et al., 2013).
Description:
The histone H1 and HASPB1 proteins were purified from endotoxins under pyrogenic free conditions in 1× PBS on a Superose 12 column (Amersham Biosciences) (Moreno et al., 2007).
Description:
Montanide™ ISA 720 (70% formulation, according to manufacturer's instructions, SEPPIC)
g. Immunization Route
Intradermal injection (i.d.)
h.
Dog Response
Host Strain:
Beagle
Vaccination Protocol:
Dogs received three intradermal doses (dorsum; 1 ml/dose) of each vaccine formulation for a period of 3 months. On day 0, dogs from group HASPB1 and group H1 received 100 μg of HASPB1 or histone H1 protein. On days 30 and 60 the dogs received 45 μg of either protein. Dogs in group HASPB1 + H1 received a cocktail of histone H1 and HASPB1 (100 μg each) at day 0, and 45 μg of each protein on days 30 and 60. The adjuvant used for dogs in groups HASPB1, H1 and HASPB1 + H1 was Montanide™ ISA 720 (70% formulation, according to manufacturer's instructions, SEPPIC), given on days 0 and 30. The final immunization on day 60 for groups HASPB1, H1, and HASPB1 + H1 was prepared in the absence of adjuvant to avoid side effects observed following the second dose (Moreno et al., 2007).
Challenge Protocol:
Forty-five days following the final immunization, all dogs were infected intravenously with 1 × 10^8 virulent L. infantum promastigotes (Moreno et al., 2007).
Efficacy:
Following infection with L. infantum promastigotes, five out of eight beagle dogs immunized with H1 Montanide remained free of clinical signs, compared to two out of eight dogs in the control group. The results demonstrate that H1 antigens with Montanide were able to induce partial protection against canine leishmaniasis, even under extreme experimental challenge conditions (Moreno et al., 2007).
Description:
The L. infantum histone H1 was cloned into the pGEX-KG vector (Amersham Biosciences), expressed in Escherichia coli and purified using GST affinity resin (Amersham Biosciences) (Moreno et al., 2007).
Description:
Montanide™ ISA 720 (70% formulation, according to manufacturer's instructions, SEPPIC)
g. Immunization Route
Intradermal injection (i.d.)
h.
Dog Response
Host Strain:
Beagle
Vaccination Protocol:
Dogs received three intradermal doses (dorsum; 1 ml/dose) of each vaccine formulation for a period of 3 months. On day 0, dogs from group HASPB1 and group H1 received 100 μg of HASPB1 or histone H1 protein. On days 30 and 60 the dogs received 45 μg of either protein. Dogs in group HASPB1 + H1 received a cocktail of histone H1 and HASPB1 (100 μg each) at day 0, and 45 μg of each protein on days 30 and 60. The adjuvant used for dogs in groups HASPB1, H1 and HASPB1 + H1 was Montanide™ ISA 720 (70% formulation, according to manufacturer's instructions, SEPPIC), given on days 0 and 30. The final immunization on day 60 for groups HASPB1, H1, and HASPB1 + H1 was prepared in the absence of adjuvant to avoid side effects observed following the second dose (Moreno et al., 2007).
Challenge Protocol:
Forty-five days following the final immunization, all dogs were infected intravenously with 1 × 10^8 virulent L. infantum promastigotes (Moreno et al., 2007).
Efficacy:
Following infection with L. infantum promastigotes, four out of eight beagle dogs immunized with HASPB1 Montanide remained free of clinical signs, compared to two out of eight dogs in the control group. The results demonstrate that HASPB1 antigens with Montanide were able to induce partial protection against canine leishmaniasis, even under extreme experimental challenge conditions (Moreno et al., 2007).
Description:
20 μg of MPL®-SE (GlaxoSmithKline Biologicals, Rixensant, Belgium) (Goto et al., 2007).
f. Immunization Route
subcutaneous injection
g.
Mouse Response
Host Strain:
C57BL/6
Vaccination Protocol:
Mice were immunized with 10 μg of rSMT plus 20 μg of MPL®-SE in a volume of 0.1 ml. Another group of mice was administrated with 10 μg of rSMT alone. Control groups received either saline or MPL®-SE alone. The mice were immunized subcutaneously three times at three weeks intervals in the right hind footpad and at the base of the tail (Goto et al., 2007).
Challenge Protocol:
Mice were challenged with L. infantum three weeks after the last immunization. 5 × 10^6 L. infantum promastigotes were suspended in Hank's balanced salt solution and injected i.v. into the tail vein of the mouse (Goto et al., 2007).
Efficacy:
Significant reduction of parasites was seen in mice immunized with rSMT plus MPL®-SE compared with those in saline or adjuvant alone groups. The immunized mice showed 43-fold and 55-fold reduction in the number of parasites in spleens, 111-fold and 117-fold reduction in livers compared with saline and adjuvant alone groups, respectively (Goto et al., 2007).
The HSP70-II null mutant (∆hsp70-II::NEO/∆hsp70-II::HYG) is a cloned line that was generated by targeted deletion of both HSP70-II alleles in the L. infantum strain MCAN/ES/96/BCN150 [32]. L. major promastigote (strain MHOM/IL/80/Friedlin; clon V1) were also used in this study. Promastigotes of both species were grown in RPMI 1640 culture medium supplemented with 10% heatinactivated FBS, 100 U/ml penicillin and 100 µg/ml streptomycin (Carrion et al., 2011).
f. Immunization Route
Intraperitoneal injection (i.p.)
g.
Mouse Response
Host Strain:
BALB/c mouse
Persistence: L. infantum parasites lacking the HSP70-II gene have a virulence greatly reduced (Carrion et al., 2011).
Efficacy:
Inoculation of ∆HSP70-II parasites protects BALB/c mice against L. major challenge (Carrion et al., 2011).
Host Gene Response of
Ighv1-9
Gene Response:
The IgG2a titers were high for all groups with differing inoculation routes, suggesting that infection with ΔHSP70-II parasites, independent of the inoculation route, leads to a predominant production of anti-Leishmania antibodies of the IgG2a isotope. Antibody titers were determined by ELISA before and 4 weeks after inoculation and showed an increase between the two samples. IgG2a titers were significantly higher than IgG1 titers (Carrion et al., 2011).
Eukaryotic expression plasmid pcDNA3 (Invitrogen, San Diego, Calif.) (Iborra et al., 2003)
h. Immunization Route
Intramuscular injection (i.m.)
i.
Mouse Response
Host Strain:
BALB/c
Vaccination Protocol:
In DNA immunization experiments, mice were inoculated twice intramuscularly (i.m.) in both quadriceps with 100 μg of DNA (50 μg per leg) of either pcDNA3-LiP0 or pcDNA3 (controls) in a total volume of 100 μl of PBS. When “prime-boost” immunization was carried out, two inoculations of DNA and two inoculations of recombinant protein were administered. In all groups, the mice were inoculated at 2-week intervals (Iborra et al., 2003).
Challenge Protocol:
Two weeks after the final inoculation, immunized mice were challenged with 5 × 10^4 stationary-phase promastigotes of L. major that were suspended in 50 μl of PBS and injected into the left hind footpad (Iborra et al., 2003).
Efficacy:
Three weeks after challenge, the parasite burden was found to be significantly lower in mice vaccinated with pcDNA3-LiP0 than in controls. Mice vaccinated with LiP0-DNA had a 99.1% reduction in the parasite burden 3 weeks after infection compared with mice vaccinated with control DNA (Iborra et al., 2003).
Description:
The gene encoding L. infantum p36/LACK protein was expressed by recombinant vaccinia virus, and co-expressed murine IL-12 (Gonzalo et al., 2001).
Recombinant vaccinia virus (VVr) derived from the wild-type Western Reserve strain (WR) (Gonzalo et al., 2001).
h. Immunization Route
Intraperitoneal injection (i.p.)
i.
Mouse Response
Host Strain:
BALB/c
Vaccination Protocol:
Mice were primed with VVr (5 × 10^7 PFU/mouse) by the intraperitoneal (i.p.) route. Two weeks later (14 days p.i.), animals were boosted with VVr or recombinant p36 antigen (Gonzalo et al., 2001).
Challenge Protocol:
35 days p.i., mice were challenged in the right hind foot with 10^5 of L. major stationary-phase promastigote culture (Gonzalo et al., 2001).
Efficacy:
BALB/c mice immunized with a DNA vector expressing p36/LACK of Leishmania infantum followed by a booster with VVp36/LACK induced significant protection against Leishmania major infection (Gonzalo et al., 2001).
V. References
1. Carrion et al., 2011: Carrion J, Folgueira C, Soto M, Fresno M, Requena JM. Leishmania infantum HSP70-II null mutant as candidate vaccine against leishmaniasis: a preliminary evaluation. Parasites & vectors. 2011; 4(1); 150. [PubMed: 21794145].
2. Dias et al., 2018: Dias DS, Ribeiro PAF, Martins VT, Lage DP, Ramos FF, Dias ALT, Rodrigues MR, Portela ÁSB, Costa LE, Caligiorne RB, Steiner BT, Chávez-Fumagalli MA, Salles BCS, Santos TTO, Silveira JAG, Magalhães-Soares DF, Roatt BM, Machado-de-Ávila RA, Duarte MC, Menezes-Souza D, Silva ES, Galdino AS, Coelho EAF. Recombinant prohibitin protein of Leishmania infantum acts as a vaccine candidate and diagnostic marker against visceral leishmaniasis. Cellular immunology. 2018; 323; 59-69. [PubMed: 29128045].
3. Gonzalo et al., 2001: Gonzalo RM, RodrÃguez JR, RodrÃguez D, González-Aseguinolaza G, Larraga V, Esteban M. Protective immune response against cutaneous leishmaniasis by prime/booster immunization regimens with vaccinia virus recombinants expressing Leishmania infantum p36/LACK and IL-12 in combination with purified p36. Microbes and infection / Institut Pasteur. 2001; 3(9); 701-711. [PubMed: 11489418].
4. Goto et al., 2007: Goto Y, Bogatzki LY, Bertholet S, Coler RN, Reed SG. Protective immunization against visceral leishmaniasis using Leishmania sterol 24-c-methyltransferase formulated in adjuvant. Vaccine. 2007; 25(42); 7450-7458. [PubMed: 17804125].
5. Iborra et al., 2003: Iborra S, Soto M, Carrión J, Nieto A, Fernández E, Alonso C, Requena JM. The Leishmania infantum acidic ribosomal protein P0 administered as a DNA vaccine confers protective immunity to Leishmania major infection in BALB/c mice. Infection and immunity. 2003; 71(11); 6562-6572. [PubMed: 14573678].
6. Moreno et al., 2007: Moreno J, Nieto J, Masina S, Cañavate C, Cruz I, Chicharro C, Carrillo E, Napp S, Reymond C, Kaye PM, Smith DF, Fasel N, Alvar J. Immunization with H1, HASPB1 and MML Leishmania proteins in a vaccine trial against experimental canine leishmaniasis. Vaccine. 2007; 25(29); 5290-5300. [PubMed: 17576026].
7. Mortazavidehkordi et al., 2016: Mortazavidehkordi N, Farjadfar A, Khanahmad H, Ghayour Najafabadi Z, Hashemi N, Fallah A, Najafi A, Kia V, Hejazi SH. Evaluation of a novel lentiviral vaccine expressing KMP11-HASPB fusion protein against Leishmania infantum in BALB/c mice. Parasite immunology. 2016; 38(11); 670-677. [PubMed: 27540714].
8. Saljoughian et al., 2013: Saljoughian N, Taheri T, Zahedifard F, Taslimi Y, Doustdari F, Bolhassani A, Doroud D, Azizi H, Heidari K, Vasei M, Namvar Asl N, Papadopoulou B, Rafati S. Development of novel prime-boost strategies based on a tri-gene fusion recombinant L. tarentolae vaccine against experimental murine visceral leishmaniasis. PLoS neglected tropical diseases. 2013; 7(4); e2174. [PubMed: 23638195].
