ELISA-based evaluation of antibody response to Leishmania in a region endemic for cutaneous leishmaniasis.

Leishmaniasis includes several clinical forms. While routine diagnosis of cutaneous leishmaniasis (CL) is by microscopy, an antibody response to CL has been reported in several recent studies. This study evaluated anti-leishmanial immunoglobulin G (IgG) antibody responses as a biomarker of active leishmaniasis and a measure of exposure to Leishmania. Sera from 50 untreated CL patients, 140 patients under treatment and 280 healthy individuals residing in endemic regions collected as part of an epidemiological survey, was analysed with an enzyme-linked immunosorbent assay established in-house using receiver operator characteristic curve at optimized cut-off value. The assay showed high performance as a diagnostic tool in identifying exposure in endemic individuals (sensitivity: 98%, specificity: 90.3%). All patients showed lower antibody levels over time since onset of lesion/s. Antibody levels were higher (p Ë‚ .01) and persisted for a longer period in untreated patients. In patients under treatment, the level of anti-IgG antibodies was negatively correlated with the total duration the patient had been on treatment. The anti-leishmanial IgG response in Leishmania donovani-induced CL is transient and is unlikely to confer protective immunity. Optimized serological assays may be useful in endemic settings for diagnosis and monitoring the treatment response in CL.

A highly sensitive modified nested PCR to enhance case detection in leishmaniasis.

BACKGROUND: Human leishmaniasis is one of the major parasitic diseases with worldwide distribution. Sri Lanka is a recently established focus of leishmaniasis caused by a variant Leishmania donovani. Early case detection and management is a main approach identified for L. donovani control in the regional leishmaniasis elimination drive. Usefulness of light microscopy and in-vitro culture are limited in chronic, atypical or treated lesions though timely and accurate detection of all light microscopy/in-vitro culture negative cases of all forms of leishmaniasis is necessary for treatment. Timely treatment is important to minimize risk for death in visceral disease and undesired sequelae of long standing infection and illness on both patients and community. We described a 100% sensitive, Leishmania spp. specific modified version of a nested PCR (Mo-STNPCR) that also minimizes carry over and cross contaminations while facilitate investigation of light microscopy and in-vitro culture negative clinically suggestive cases of leishmaniasis. METHODS: Leishmania DNA was amplified using previously published P221: 5'-GGTTCCTTTCCTGATTTACG-3' and P332: 5'-GGCCGGTAAAGGCCGAATAG-3'outer primers followed by a nested reaction using P223: 5'-TCCCATCGCAACCTCGGTT-3' and P333: 5'-AAGCGGGCGCGGTGCTG-3' inner primers that by passes the requirement of tube handling between the two steps of the conventional nested PCR. Leishmania DNA was detected in a range of infected tissue material. Infected material from patients with cutaneous leishmaniasis (n = 30), visceral leishmaniasis (n = 10) and from a control group including patients with non-leishmanial skin diseases (n = 10), other systemic diseases (n = 10) and healthy individuals (n = 10) were examined with Mo-STNPCR. Results were further compared with those of light microscopy and in-vitro culture. RESULTS: Mo-STNPCR method was 100% sensitive and 100% specific for diagnosis of leishmaniasis. Light microscopy and in-vitro culture were positive in 75.0% (n = 30/40) and 72.5% (n = 29/40) samples respectively where combined results of them gave 87.5% (n = 35/40) sensitivity. Mo-STNPCR did not cross react with control samples. Furthermore, Mo-STNPCR reduces the risk of cross-contaminations and carry over contaminations since the full reaction is carried out without opening the tubes. Per patient cost was calculated as 22 USD while the same was 3 and 6 USD for light microscopy and in-vitro culture respectively. CONCLUSION: Mo-STNPCR method is a useful tool in detecting leishmaniasis in minority of cases that go undetected by first line investigations.

Synthesis and biological evaluation of polyhydroxylated oxindole derivatives as potential antileishmanial agent.

The devastating appearance of numerous drug-unresponsive strains of Leishmania donovani and severe toxic side effects of conventional antileishmanial therapy necessitates the search for novel leads, to treat visceral leishmaniasis efficiently. The current study deals with the synthesis and biological evaluation of a unique C-5 functionalized oxindole based polyphenol to ascertain its activities against L. donovani infection, in vitro. The polyhydroxylated oxindole derivative (1) was generated by coupling styrene derivatives with 5-bromo bis-arylidene oxindole using Heck coupling reaction. The synthesized molecule 1 was tested for its antileishmanial activity using both promastigote and amastigote stages of L. donovani. Molecule 1 showed promising anti-promastigote and anti-amastigote activities with IC50 values 15 µM and 1 µM, respectively, with no cytotoxicity towards host splenocytes. The results revealed that this compound induced parasite death by promoting oxidative stress, thereby triggering apoptosis.

In-Vitro Activity of Silybin and Related Flavonolignans against Leishmania infantum and L. donovani.

Flavonolignans from the seeds of the milk thistle (Silybum marianum) have been extensively used in folk medicine for centuries. Confirmation of their properties as hepatoprotective, antioxidant and anticancer has been obtained using standardized extracts and purified flavonolignans. Information on their potential effect on Leishmania is very scarce. We have investigated the effect of silymarin, silybin and related flavonolignans on the multiplication of promastigotes in vitro and ex vivo on intracellular amastigotes of L. infantum (Li) and L. donovani (Ld), causative agents of human and canine visceral leishmaniasis (VL). In addition, the potential synergistic effect of the most active molecule and well-established antileishmanial drugs against promastigotes was explored. Dehydroisosilybin A elicited the highest inhibition against Ld and Li promastigotes with an approximate IC50 of 90.23 µM. This molecule showed a moderate synergism with amphotericin B (AmB) but not with SbIII or paromomycin, although it was ineffective against amastigotes. Antileishmanial activity on intracellular amastigotes of the two diastereoisomers of dehydrosilybin (10 µM) was comparable to that elicited by 0.1 µM AmB. Antiproliferative activity and safety of flavonolignans suggest the interest of exploring their potential value in combination therapy against VL.

Adenosine generated by ectonucleotidases modulates the host immune system during visceral leishmaniasis.

Adenosine, an endogenous purine nucleoside is one such extracellular signaling molecule whose role in the regulation of anti-inflammatory cytokines and immune pathogenicity in visceral leishmaniasis is indeterminate. Here, we have evaluated the adenosine in the plasma of 20 visceral leishmaniasis (VL) patients during active disease and after successful treatment. We observed the elevated plasma adenosine during active VL disease (26.73±1.95µM) and the level subsides as the treatment progresses and falls to the normal level after successful treatment (4.32±0.45µM). We demonstrated a direct correlation between changes in the plasma adenosine level and the Th1/Th2 balance in VL patients and it was corroborated with in vitro experiment. Further, we delineated the molecular mechanism involved in the elevation of plasma adenosine during visceral leishmaniasis. Our results reveal that the elevated plasma adenosine level associated with pathogenicity and plays a critical role in skewing immune response from Th1 to Th2 type to influence the outcome of the disease.

A severe case of visceral leishmaniasis and liposomal amphotericin B treatment failure in an immunosuppressed patient 15 years after exposure.

BACKGROUND: Visceral leishmaniasis (VL) is a protozoan disease, which is responsible for 200.000-400.000 yearly infections worldwide. If left untreated, the fatality rate can be as high as 100% within 2 years. 90% of cases occur in just six countries: India, Bangladesh, Sudan, South Sudan, Ethiopia and Brazil. It is thus a disease rarely seen by physicians in Europe or North America. We report on the fatal case of VL in an 80-year-old immunosuppressed patient who presented with a latency of over 15 years after having visited an endemic region. This is the first report showing such extreme latency of VL in a European traveller. This case is furthermore unusual because it suggests primary treatment failure to liposomal amphotericin B. CASE PRESENTATION: An 80-year-old man who was on immunosuppressive treatment due to a non-specific inflammatory disease of the liver and kidney presented to our hospital with recurrent fever, fatigue and bloody diarrhoea. Histopathological analysis from a colon biopsy showed intracellular amastigotes. The diagnosis of VL was confirmed by polymerase-chain-reaction (PCR) of the colon biopsy. PCR was also performed in plasma, a bronchopulmonary lavage, a lymph node, liver and bone marrow biopsy and proved L. donovani as causative species. The disseminated infection was unresponsive to treatment with liposomal amphotericin B as recommended in immunosuppressed individuals despite stopping immunosuppressive treatment. CONCLUSION: Imported cases of VL to non-endemic regions are increasing due to extensive international travel and migration. Furthermore, the increase of elderly patients and immunosuppressed individuals, secondary to HIV, post-transplant and chemotherapeutic agents, has resulted in an increase of VL also in endemic regions of Europe. It is thus important for physicians to be able to recognize the infection. This case also demonstrates treatment failure to amphotericin B, which was only a known problem in patients with HIV until now. The knowledge of this as a possible complication is important for specialists treating the disease.

Up regulation of A2B adenosine receptor on monocytes are crucially required for immune pathogenicity in Indian patients exposed to Leishmania donovani.

Adenosine, an endogenous purine nucleoside is one such extracellular signalling molecule whose role in regulation of anti-inflammatory cytokines and immune pathogenicity in visceral leishmaniasis is not fully understood. Here, we investigated the relationship between Leishmania donovani infection and expression of A2B receptor on monocytes in VL patients in their pre and post treatment stage. We also investigated the molecular mechanisms influencing the interaction between immunopathogenicity and infection by exposing Leishmania donovani pulsed macrophages to Adenosine. A direct correlation of up-regulated A2B expression on monocytes with increased parasite load was also observed. Our results also suggested that A2B receptor activation is critically required for the stimulatory effect of adenosine on IL-10 production and suppression of nitric oxide release. The stimulatory effect of adenosine on Leishmania donovani induced IL-10 production required ERK1/2 activation and is p-38 MAPK independent.

Effective anti-leishmanial activity of minimalist squaramide-based compounds.

In order to evaluate the in vitro leishmanicidal activity of N,N'-Squaramides derivatives, compounds that feature both hydrogen bond donor and acceptor groups and are capable of multiple interactions with complementary sites, against Leishmania infantum, Leishmania braziliensis and Leishmania donovani a series of 18compounds was prepared and assayed on extracellular and intracellular parasite forms. Infectivity and cytotoxicity tests were performed on J774.2 macrophage cells using meglumine antimoniate (Glucantime) as the reference drug. Changes in metabolite excretion by 1H-NMR and the ultrastructural alterations occurring in the parasites treated using transmission electron microscopy (TEM), was analyzed. Compounds 1, 7, 11, 14 and 17 were the more active and less toxic. Infection rates showed that the order of effectiveness was 17 > 11 > 14 > 7 for both L. infantum and L. braziliensis and in the same way, the compound 1 for L. donovani. All these compounds have altered the typical structure of the promastigotes, glycosomes and mitochondria. These severe modifications by the compounds are the ultimate reasons for the alterations observed in the excretion products. The Squaramide 17 (3-(butylamino)-4-((3-(dimetilamino)propyl)(methyl)amino)cyclobut-3-en-1,2-dione) was clearly the most efficient of all compounds. The data appear to confirm that the severe modifications generated in organelles such as glycosomes or mitochondria by the compounds are the ultimate reasons for the alterations observed in the excretion products of all species. The activity, stability, low cost of starting materials, and straightforward synthesis make amino squaramides appropriate molecules for the development of an affordable anti-leishmanial agent.

Preliminary survey of domestic animal visceral leishmaniasis and risk factors in north-west Ethiopia.

OBJECTIVE: After the epidemics of L. donovani complex in 2004/05 in human patients, to investigate the presence of antibodies against L. donovani in domestic animals in north-west Ethiopia. METHODS: Two hundred and three domestic animals were screened. Serum and biopsy samples were collected. A modified direct agglutination test (DAT) for canine reservoirs was used to screen serum samples at ≥ 1:320 cut-off titre. Giemsa stain and culture on Novy macNeal Nicolae (NNN) media were used for biopsy samples. Pre-tested questionnaires were used to elicit information on potential risk factors. RESULTS: Antibody against L. donovani in domestic animals was detected in 30.5% of animals. The highest seropositivity rates were 41.9% in cattle, 40% in dogs, 33.3% in donkeys, 10% in goats and 4.8% in sheep. No Leishmania parasite was isolated from spleen, liver, skin snip and exudates, bone marrow or lymph node of dogs. Dogs owned by households with history of kala-azar treatment and humans sharing the house with cattle were more affected by visceral leishmaniasis (P < 0.05). CONCLUSION: This study showed a high serological prevalence of leishmaniasis in domestic animals. Their role in the epidemiology of visceral leishmaniasis remains unclear.

Discovery of potent nitrotriazole-based antitrypanosomal agents: In vitro and in vivo evaluation.

3-Nitro-1H-1,2,4-triazole- and 2-nitro-1H-imidazole-based amides with an aryloxy-phenyl core were synthesized and evaluated as antitrypanosomal agents. All 3-nitrotriazole-based derivatives were extremely potent anti-Trypanosoma cruzi agents at sub nM concentrations and exhibited a high degree of selectivity for the parasite. The 2-nitroimidazole analogs were only moderately active against T. cruzi amastigotes and exhibited low selectivity. Both types of compound were active against Leishmania donovani axenic amastigotes with excellent selectivity for the parasite, whereas three 2-nitroimidazole-based analogs were also moderately active against infected macrophages. However, no compound demonstrated selective activity against Trypanosoma brucei rhodesiense. The most potent in vitro anti-T. cruzi compounds were tested in an acute murine model and reduced the parasites to an undetectable level after five days of treatment at 13 mg/kg/day. Such compounds are potential inhibitors of T. cruzi CYP51 and, being excellent substrates for the type I nitroreductase (NTR) which is specific to trypanosomatids, work as prodrugs and constitute a new generation of effective and more affordable antitrypanosomal agents.

Synthesis, antileishmanial activity and docking study of N'-substitutedbenzylidene-2-(6,7-dihydrothieno[3,2-c]pyridin-5(4H)-yl)acetohydrazides.

A series of N'-substitutedbenzylidene-2-(6,7-dihydrothieno[3,2-c]pyridin-5(4H)-yl)acetohydrazide derivatives is synthesized and evaluated for antileishmanial activity against Leishmania donovani promastigotes. Compounds 9a and 9i were shown significant antileishmanial when compared with standard sodium stilbogluconate. Antimicrobial study revealed that compound 9b has potent as well as broad spectrum antibacterial activity when compared with ampicillin and compound 9e showed promising antifungal activity when compared with miconazole. Also, none of the synthesized compounds showed cytotoxicity up to tested concentration. Further, docking study against pteridine reductase 1 enzyme of L. donovani showed good binding interactions. ADME properties of synthesized compounds were also analyzed and showed potential to develop as good oral drug candidates.

The isolation of antiprotozoal compounds from Libyan propolis.

Propolis is increasingly being explored as a source of biologically active compounds. Until now, there has been no study of Libyan propolis. Two samples were collected in North East Libya and tested for their activity against Trypanosoma brucei. Extracts from both samples had quite high activity. One of the samples was fractionated and yielded a number of active fractions. Three of the active fractions contained single compounds, which were found to be 13-epitorulosal, acetyl-13-epi-cupressic acid and 13-epi-cupressic acid, which have been described before in Mediterranean propolis. Two of the compounds had a minimum inhibitory concentration value of 1.56 µg/mL against T. brucei. The active fractions were also tested against macrophages infected with Leishmania donovani, and again moderate to strong activity was observed with the compounds having IC50 values in the range 5.1-21.9 µg/mL.

Screening of traditional medicinal plant extracts and compounds identifies a potent anti-leishmanial diarylheptanoid from Siphonochilus aethiopicus.

Available anti-leishmanial drugs are associated with toxic side effects, necessitating the search for safe and effective alternatives. This study is focused on identifying traditional medicinal plant natural products for anti-leishmanial potential and possible mechanism of action. Compounds S and T. cordifolia residual fraction (TC-5) presented the best anti-leishmanial activity (IC50: 0.446 and 1.028 mg/ml) against promastigotes at 48 h and less cytotoxicity to THP-1 macrophages. These test agents elicited increased expression of pro-inflammatory cytokines; TNFα and IL-12. In infected untreated macrophages, NO release was suppressed but was significantly (p < 0.05) increased in infected cells treated with compound S. Importantly, Compound S was found to interact with LdTopoIIdimer in silico, resulting in a likely reduced ability of nucleic acid (dsDNA)-remodelling and, as a result, parasite proliferation in vitro. Thereby, Compound S possesses anti-leishmanial activity and this effect occurs via a Th1-mediated pro-inflammatory response. An increase in NO release and its inhibitory effect on LdTopoII may also contribute to the anti-leishmanial effect of compound S. These results show the potential of this compound as a potential starting point for the discovery of novel anti-leishmanial leads.Communicated by Ramaswamy H. Sarma.

Datasets of Iso-Seq transcripts for decoding transcriptome complexity in four Leishmania species.

The Iso-Seq technology, based on PacBio sequencing, enables the generation of high-quality, full-length transcripts, providing insights into transcriptome complexity. In this study, total RNA from promastigotes of four Leishmania species (Leishmania braziliensis, Leishmania donovani, Leishmania infantum and Leishmania major) was sequenced using Single Molecule, Real-Time (SMRT) Sequencing (PacBio) methodology. The Iso-seq transcripts were categorized as either complete or truncated according to the presence or absence of the Spliced-Leader (SL) sequence at their 5'-end, respectively. Moreover, only transcripts having a poly-A+ at their 3'-end were considered. Supplied datasets represent valuable information that may help to uncover novel transcripts and alternative splicing events in a parasite that regulates its gene expression at the post-transcriptional level. A better knowledge of gene expression regulation in Leishmania will open avenues for the development of new drugs to treat leishmaniasis, a devastating disease that has worldwide distribution. Additionally, the bioinformatics pipeline followed here may guide the analysis of Iso-Seq data derived from related trypanosomatids like Trypanosoma cruzi (Chagas disease agent) and Trypanosoma brucei (sleeping disease). © 2023 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

In vitro drug susceptibility using a parasite-rescue and transformation assay of Leishmania (Mundinia) martiniquensis and Leishmania (Mundinia) orientalis amastigotes against antileishmanial drugs.

Leishmaniasis is an emerging infectious disease in Thailand, with Leishmania martiniquensis and Leishmania orientalis identified as the primary causative agents among immunocompetent and immunocompromised individuals. Variations in drug susceptibility among different Leishmania species have been reported in different regions. Therefore, drug susceptibility assays are essential to assess the effectiveness of antileishmanial drugs used or potentially used in the affected areas. This study investigated the in vitro drug sensitivity of L. martiniquensis and L. orientalis, along with two reference species causing VL, namely L. donovani and L. infantum, against six antileishmanial drugs. Using a parasite-rescue and transformation assay, the results demonstrated that the IC50 values of amphotericin B (AmB), miltefosine (MIL), and sodium stibogluconate (Sb(III)) against all Leishmania species tested were within the sensitive range of each drug. On the contrary, the IC50 values of artemisinin (ART) and dihydroartemisinin (DHA), drugs primarily used for malaria treatment, were outside the sensitive range of the Leishmania species tested except L. infantum. This in vitro study highlights that AmB could effectively exhibit good sensitivity against the intracellular amastigotes of L. martiniquensis and L. orientalis. Also, MIL and Sb(III) could be considered alternative drugs for antileishmanial treatment in Thailand.

Epithelial homelessness: an atypical form of anoikis triggered by Leishmania interaction with epithelial cells.

Aim: Leishmaniasis is characterized by a spectrum of diseases with two main clinical forms, cutaneous and visceral, caused by Leishmania tropica and Leishmania donovani, respectively. Studying Leishmania's interaction with the epithelial barrier at the initial site of a bite is crucial to understanding the establishment of the disease. Materials & methods: To discern parasite-host epithelial interaction, we developed in vitro cellular models involving co-cultures of Leishmania and MDCK epithelial cells. Results: Both L. donovani-MDCK and L. tropica-MDCK co-culture models demonstrated a phenomenon known as atypical anoikis apoptosis, typically identified by distinctive 'flipping in' of cell membranes and disordered cytoskeletal frameworks. Conclusion: This study bridges the gap in the fundamental understanding of the intricate latticework involving vector-Leishmania-host and may inform drug development strategies.

Small parasites called Leishmania are passed to humans through the bites of sandflies. These parasites cause three deadly forms of disease: one that affects the organs, one that causes skin lesions and one that affects organ linings. This study looked at how Leishmania parasites behave when they enter through the skin. We found that when the parasites were in contact with cells, the cells changed their shape and lost contact with neighboring cells. This led to a type of cell death known as anoikis, a Greek term meaning 'homelessness'.

Design and synthesis of novel halogen rich salicylanilides as potential antileishmanial agents.

The available therapeutic treatment for leishmaniasis is inadequate and toxic due to side effects, expensive and emergence of drug resistance. Affordable and safe antileishmanial agents are urgently needed and toward this objective, we synthesized a series of 32 novel halogen rich salicylanilides including niclosamide and oxyclozanide and investigated their antileishmanial activity against amastigotes of Leishmania donovani. In vitro data showed fifteen compounds inhibited intracellular amastigotes with an IC50 of below 5 µM and selectivity index above 10. Among 15 active compounds, 14 and 24 demonstrated better activity with an IC50 of 2.89 µM and 2.09 µM respectively and selectivity index is 18. Compound 24 exhibited significant in vivo antileishmanial efficacy and reduced 65% of the splenic parasite load on day 28th post-treatment in the experimental visceral leishmaniasis golden hamster model. The data suggest that 24 can be a promising lead candidate possessing potential to be developed into a leishmanial drug candidate.

Evaluation of the inhibitory potential of Valproic acid against histone deacetylase of Leishmania donovani and computational studies of Valproic acid derivatives.

Valproic acid (VA) is a proven inhibitor of human histone deacetylases (HDACs). The homogenous HDAC has been associated with all major human parasitic pathogens and hence, it has been considered an attractive drug target for anti-leishmanial therapy. To assist in drug design endeavors for HDACs, an in-vitro study has been presented to investigate the VA inhibition on Leishmania donovani HDAC (LdHDAC). The regression analysis of VA by 24 hrs viability assay confirmed its activity against LdHDAC. Moreover, the toxicity of VA is also well documented. Thus, the in-silico experiments were also conducted to screen the non-toxic VA derivatives as anti-leishmanial drug candidates having potential as inhibitors of LdHDAC. For in-silico study, the 3D structure of target LdHDAC was developed by homology modeling. Based on their in-silico activity, we shortlisted 13 VA derivatives having maximum affinity for LdHDAC and identified four potential derivatives that can specifically bind to this protein. After that, these ligands were subjected to molecular dynamics simulation. These derivatives may be effective against L. donovani promastigotes since they followed Lipinski's RO5 and were non-toxic. Thus, screened derivatives can be considered as lead ligands for targeting LdHDAC and may be used as possible drug candidates to treat leishmaniasis and overcome the limitation of anti-leishmanial drugs. This is the first report of antileishmanial potential of VA and its derivatives targeting LdHDAC. Hence, the current investigation presents a search for novel target specific drugs to aid the anti-leishmanial drug development.Communicated by Ramaswamy H. Sarma.

Review on the Drug Intolerance and Vaccine Development for the Leishmaniasis.

Leishmaniasis is one of the Neglected Tropical Diseases (NTDs), a zoonotic disease of vector-borne nature that is caused by a protozoan parasite Leishmania. This parasite is transmitted by the vector sandfly into the human via a bite. Visceral leishmaniasis (VL), also called kala-azar, is the most fatal among the types of leishmaniasis, with high mortality mostly spread in the East Africa and South Asia regions. WHO report stated that approximately 3.3 million disabilities occur every year due to the disease along with approximately 50,000 annual deaths. The real matter of concern is that there is no particular effective medicine/vaccine available against leishmaniasis to date except a few approved drugs and chemotherapy for the infected patient. The current selection of small compounds was constrained, and their growing drug resistance had been a major worry. Additionally, the serious side effects on humans of the available therapy or drugs have made it essential to discover efficient and low-cost methods to speed up the development of new drugs against leishmaniasis. Ideally, the vaccine could be a low risk and effective alternative for both CL and VL and elicit long-lasting immunity against the disease. There are a number of vaccine candidates at various stages of clinical development and preclinical stage. However, none has successfully passed all clinical trials. But, the successful development and approval of commercially available vaccines for dogs against canine leishmaniasis (CanL) provides evidence that it can be possible for humans in distant future. In the present article, the approaches used for the development of vaccines for leishmaniasis are discussed and the progress being made is briefly reviewed.

Evaluation of immunomodulatory potential of recombinant histidyl-tRNA synthetase (rLdHisRS) protein of Leishmania donovani as a vaccine candidate against visceral leishmaniasis.

Visceral leishmaniasis is neglected tropical protozoan disease caused by Leishmania donovani and are associated with high fatality rate in developing countries since prophylactic vaccines are not available. In the present study, we evaluated the immunomodulatory potential of L. donovani histidyl-tRNA synthetase (LdHisRS) and predicted the epitopes using immunoinformatic tools. Histidyl-tRNA synthetase (HisRS) is a class IIa aminoacyl t-RNA synthetase enzyme (aaRS) required for histidine incorporation into proteins during protein synthesis. The recombinant LdHisRS protein (rLdHisRS) was expressed in E coli BL-21cells, and its immunomodulatory role was assessed in J774A.1 murine macrophage and in BALB/c mice, respectively. LdHisRS specifically stimulated and triggered enhance cell proliferation, nitric oxide release and IFN-γ (70%; P < 0.001), and IL-12 (55.37%; P < 0.05) cytokine release in vitro, whereas BALB/c mice immunized with rLdHisRS show higher NO release (80.95%; P<0.001), higher levels of Th1 cytokines IFN-γ (14%; P < 0.05), TNF-α (34.93%; P < 0.001), and IL-12 (28.49%; P < 0.001) and robust IgG (p<0.001) and IgG2a (p<0.001) production. We also identified 20 Helper T-lymphocytes (HTLs), 30 cytotoxic T lymphocytes (CTLs), and 18 B-cell epitopes from HisRS protein of L. donovani. All these epitopes can be further used to make a multiepitope vaccine against L. donovani.