Immunology of leprosy

An update on leprosy immunopathogenesis: systematic review

Introduction

Leprosy is a chronic infectious condition and the main cause of neuropathy that occurs brought on by M. leprae. It is known that the biological characteristics of the human host, such as the immunological ones, have a higher influence on the pathology of this disease than the intrinsic mechanisms of the bacterium. The objective of this work was to review the scientific knowledge about the relationship between immunopathology and the severity of leprosy.

Methods

A systematic review following the PRISMA 2020 recommendations was conducted in the PUBMED, LILACS, SciELO and Science Direct databases using articles in English, Portuguese or Spanish between January 2011 and May 2022 with the descriptors "Leprosy/Immunology", "Cytokines" and "Mycobacterium leprae". A methodological quality assessment was carried out using the JBI checklists.

Results

A total of 49 articles were included. There is a relationship of greater severity of infection associated with lower release of MHC molecules in response to PGL-1 that inhibit the promotion of resolving T lymphocytes arising from dendritic cells (DCs) stimulation. In addition, the differentiation of macrophage phenotypes dependent on the activation of PRRs can define activation and the distinct type of T helper (Th) cells involved according to severity. Activated CD8+ T cells also have distinct types at the appropriate poles of the disease, and B cells show at the most severe pole of the LL, specific induction of IgA and more Treg-type CD8+ T cells that further contribute to T cell anergy.

Conclusion

Therefore, the adaptive immune system aggravates nerve damage and defines the type of leprosy, while the innate immune system is considerably more significant in the onset of nerve damage, symptomatic of the initial presentation of illness and in several critical immune responses, including inflammation and elimination of dead M. leprae.

Sequential trypsin and ProAlanase digestions unearth immunological protein biomarkers shrouded by skeletal collagen

This study investigates the efficacy of proteomic analysis of human remains to identify active infections in the past through the detection of pathogens and the host response to infection. We advance leprosy as a case study due to the sequestering of sufferers in leprosaria and the suggestive skeletal lesions that can result from the disease. Here we present a sequential enzyme extraction protocol, using trypsin followed by ProAlanase, to reduce the abundance of collagen peptides and in so doing increase the detection of non-collagenous proteins. Through our study of five individuals from an 11th to 18th century leprosarium, as well as four from a contemporaneous non-leprosy associated cemetery in Barcelona, we show that samples from 2 out of 5 leprosarium individuals extracted with the sequential digestion methodology contain numerous host immune proteins associated with modern leprosy. In contrast, individuals from the non-leprosy associated cemetery and all samples extracted with a trypsin-only protocol did not. Through this study, we advance a palaeoproteomic methodology to gain insights into the health of archaeological individuals and take a step toward a proteomics-based method to study immune responses in past populations.

New threats from an old foe: Evaluating the risk to the blood supply due to increasing incidence and endemicity of leprosy in the United States

Leprosy (i.e., Hansen's disease) is a chronic disease secondary to infection with either Mycobacterium leprae or M. lepromatosis. While the incidence of this disease is decreasing across the world, there is mounting evidence that it might be increasing, and becoming endemic, in the United States. Leprosy was once considered a potential threat to the blood supply, and while this threat has not borne out, it is worth revisiting the available data to assess whether it may pose a threat in the future. Herein, we discuss the evidence for and against the potential for transfusion-transmission of leprosy, and highlight future areas of research to further elucidate this possibility.

Xenophagy as a Strategy for Mycobacterium leprae Elimination during Type 1 or Type 2 Leprosy Reactions: A Systematic Review

BACKGROUND

Mycobacterium leprae is an intracellular bacillus that causes leprosy, a neglected disease that affects macrophages and Schwann cells. Leprosy reactions are acute inflammatory responses to mycobacterial antigens, classified as type1 (T1R), a predominant cellular immune response, or type2 (T2R), a humoral phenomenon, leading to a high number of bacilli in infected cells and nerve structures. Xenophagy is a type of selective autophagy that targets intracellular bacteria for lysosomal degradation; however, its immune mechanisms during leprosy reactions are still unclear. This review summarizes the relationship between the autophagic process and M. leprae elimination during leprosy reactions.

METHODS

Three databases, PubMed/Medline (n = 91), Scopus (n = 73), and ScienceDirect (n = 124), were searched. After applying the eligibility criteria, articles were selected for independent peer reviewers in August 2023.

RESULTS

From a total of 288 studies retrieved, eight were included. In multibacillary (MB) patients who progressed to T1R, xenophagy blockade and increased inflammasome activation were observed, with IL-1β secretion before the reactional episode occurrence. On the other hand, recent data actually observed increased IL-15 levels before the reaction began, as well as IFN-γ production and xenophagy induction.

CONCLUSION

Our search results showed a dichotomy in the T1R development and their relationship with xenophagy. No T2R studies were found.

Cytokines profile in pure neural leprosy

Introduction

Pure Neural Leprosy (PNL) is a form of this long time known disease that affects only the peripheral nervous system. Since it is a rare form of the disease, its pathophisiology is still poorly understood.

Objective

Describe the cytokines profile in patients with PNL.

Methods

30 Patients diagnosed with PNL in the Souza Araujo Outpatient Clinic and with cytokines evaluated were selected. They were evaluated by neurologists and diagnosed after a nerve biopsy. Serum levels of IL-1 β, IL-6, IL-10, IL-17, TNF, CCL-2/MCP-1, IFN-ϒ, CXCL-10/IP-10 and TGF-β were evaluates at the moment of the diagnosis.

Results

Neural thickening was a common clinical finding in this groups of patients. Small and medium sensitive fibers signs and symptoms were present in 92% of the patients and motor involvement in 53%. 43% of patients presented neuropathic pain and no one had neuritis TGF-beta, IL-17, CCl-2 and IP-10. CCL-2 levels were associated with demyelinating patters and IP-10 and IL-1o were associated with axonal patterns at NCS.

Discussion

PNL patients' cytokine profile appears to be different of other clinical forms of leprosy, with the presence of cytokines described in both tuberculoid and lepromatous leprosy. High levels of CCl-2 may be related to the presence of silent neuritis as well as the presence of IL-10. PNL is unique a form of leprosy, therefore, understanding its immunological profiles essential to better understand the disease itself.

One Case of Tuberculosis-Like Leprosy with a Type I Leprosy Reaction

Leprosy is a chronic infectious disease primarily affecting the skin and peripheral nerves and is caused by Mycobacterium leprae. Although effective control measures have significantly reduced its global incidence in recent years, its insidious onset and diverse skin manifestations pose considerable challenges to early diagnosis, particularly among young medical practitioners. This study reports a case of tuberculoid leprosy accompanied by a type I reaction (T1R) to leprosy, aiming to contribute to the broader understanding and management of the disease. The patient came from a leprosy-endemic region and had a family history of leprosy. They first presented with neuritis, characterised by numbness in the left upper limb, which is an early-stage symptom often overlooked. This case accentuates the importance of comprehensive examination techniques, including bacteriological and histological investigations, ultrasound and magnetic resonance imaging, to identify early nerve damage, which is critical for prompt diagnosis and intervention. According to World Health Organization data, approximately 200,000 new cases of leprosy are reported worldwide each year, with a prevalence rate of 0.2 cases per 10,000 individuals. The disease exhibits two clinical forms based on the host's immune response: tuberculoid leprosy in a well-immunised population and lepromatous leprosy in a poorly immunised host. The patient in this study demonstrated signs of tuberculoid leprosy, marked by isolated skin papules and plaques, and a T1R, a tissue-destructive, immune-driven inflammatory process. This case underscores the need for ongoing education and updated diagnostic tools to facilitate the early detection of leprosy, particularly in endemic areas. Moreover, attention must be given to the comprehensive care of patients, encompassing both physical and psychological aspects, to improve their quality of life and mitigate social discrimination and prejudice.

Psoriasis and Leprosy: An Arcane Relationship

Purpose

Psoriasis (Ps) and leprosy are chronic inflammatory skin disorders, characterised by enhanced innate and adaptive immunity. Ps and leprosy rarely coexist. The molecular immune mechanism of the Ps and leprosy rarely coexistence is unclear.

Patients and Methods

RNA-sequencing (RNA-seq) was performed on 20 patients with Ps, 5 adults with lepromatous leprosy (L-lep), and 5 patients with tuberculoid leprosy (T-lep) to analyse the differentially expressed genes (DEGs) between them. Moreover, the biological mechanism of Ps and leprosy was explored by Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, Gene Ontology (GO) analysis, Gene Set Enrichment Analysis analysis, and protein-protein interaction (PPI) analyses. Finally, 13 DEGs of 10 skin biopsies of Ps patients, 6 samples of L-lep patients, 6 samples of T-lep patients and 5 healthy controls were confirmed by quantitative real-time polymerase chain reaction (qRT-PCR).

Results

The PPI network was constructed and primarily associated with immune response, IL-17 signalling, and Toll-like receptor pathway between Ps and leprosy. Th17 markers (interleukin (IL)-19, IL-20, IL-36A, IL-36G, IL-22, IL-17A, and lipocalin-2 (LCN2) had higher expression in Ps than in L-lep and T-lep, whereas macrophage biomarkers (CLEC4E and TREM2), SPP1, and dendritic cell (DC)-related hallmarks (ITGAX) and TNF-a had significantly lower expression across Ps and T-lep than in L-lep.

Conclusion

To put it simply, Ps patients with IL-17A, IL-19, IL-20, IL-36A, IL-36G, and IL-22 in conjunction with LCN2 with up-graduated expression might be not susceptible to L-lep. However, high levels of CLEC4E, TREM2, and SPP1 in L-lep patients indicated that they unlikely suffered from Ps.

Viral co-infections in leprosy: a scoping review

CONTEXT

The most reported viral co-infections in leprosy are human immunodeficiency virus (HIV), human T-cell lymphotropic virus (HTLV), hepatitis B virus (HBV), hepatitis C virus (HCV), and SARS-CoV-2. In co-infections, the burden of an agent can be increased or decreased by the presence of others. To address this issue, we need to fully understand their prevalence, risk factors, immunology, clinical manifestations, and treatment. The purpose of this scoping review is to describe the clinical and epidemiological characteristics of the most reported viral co-infections in leprosy to inform clinicians and guide future research.

METHODS

The authors conducted a literature search of five databases for articles on each of the aforementioned co-infections published prior to October 2022. Two independent reviewers conducted the selection process and identified 53 papers meeting the study inclusion criteria. The data extraction process and evidence synthesis were conducted by one reviewer and double-checked by a second one, consistent with best practice recommendations for scoping reviews.

RESULTS

For all assessed viruses, most studies reported prevalence rates in leprosy patients higher than the general population. Studies found that HTLV, HBV, and HCV chronic infections were highest in multibacillary leprosy, whereas HIV was mostly found in paucibacillary leprosy, and SARS-Cov-2 affected leprosy subtypes equally. Overall, co-infections were also associated with higher rates of leprosy reactions, except for COVID-19. Forty-six percent of the studies discussed issues related to treatment, which led to favorable outcomes for the most part.

CONCLUSIONS

This review summarizes the existing literature on viral co-infections in leprosy patients, generating valuable insights and recommending areas for future research.

Three-dimensional models of antigens with serodiagnostic potential for leprosy: An in silico study

BACKGROUND

Leprosy is a disease caused by Mycobacterium leprae (M. leprae), an intracellular pathogen that has tropism and affects skin and nervous system cells. The disease has two forms of presentation: Paucibacillary and multibacillary, with different clinical and immunological manifestations. Unlike what occurs in the multibacillary form , the diagnostic tests for the paucibacillary form are nonspecific and not very sensitive, allowing the existence of infected individuals without treatment, which contributes to the spread of the pathogen in the population. To mitigate this contamination, more sensitive diagnostic tests capable of detecting paucibacillary patients are needed.

AIM

To predict the three-dimensional structure models of M. leprae antigens with serodiagnostic potential for leprosy.

METHODS

In this in silico study, satisfactory templates were selected in the Protein Data Bank (PDB) using Basic Local Alignment Search Tool to predict the structural templates of ML2038, ML0286, ML0050, and 85B antigens by comparative modeling. The templates were selected according to general criteria such as sequence identity, coverage, X-ray resolution, Global Model Quality Estimate value and phylogenetic relationship; Clustal X 2.1 software was used in this analysis. Molecular modeling was completed using the software Modeller 9v13. Visualization of the models was made using ViewerLite 4.2 and PyMol software, and analysis of the quality of the predicted models was performed using the QMEAN score and Z-score. Finally, the three-dimensional moels were validated using the MolProbity and Verify 3D platforms.

RESULTS

The three-dimensional structure models of ML2038, ML0286, ML0050, and 85B antigens of M. leprae were predicted using the templates PDB: 3UOI (90.51% identity), PDB: 3EKL (87.46% identity), PDB: 3FAV (40.00% identity), and PDB: 1F0N (85.21% identity), respectively. The QMEAN and Z-score values indicated the good quality of the structure models. These data refer to the monomeric units of antigens, since some of these antigens have quaternary structure. The validation of the models was performed with the final three-dimensional structure - monomer (ML0050 and 85B antigens) and quaternary structures (ML2038 and ML0286). The majority of amino acid residues were observed in favorable and allowed regions in the Ramachandran plot, indicating correct positioning of the side chain and absence of steric impediment. The MolProbity score value and Verify 3D results of all models indicated a satisfactory prediction.

CONCLUSION

The polarized immune response against M. leprae creates a problem in leprosy detection. The selection of immunodominant epitopes is essential for the development of more sensitive serodiagnostic tests, for this it is important to know the three-dimensional structure of the antigens, which can be predicted with bioinformatics tools.

Association between SNPs in microRNAs and microRNAs-Machinery Genes with Susceptibility of Leprosy in the Amazon Population

Leprosy is a chronic neurodermatological disease caused by the bacillus Mycobacterium leprae. Recent studies show that SNPs in genes related to miRNAs have been associated with several diseases in different populations. This study aimed to evaluate the association of twenty-five SNPs in genes encoding miRNAs related to biological processes and immune response with susceptibility to leprosy and its polar forms paucibacillary and multibacillary in the Brazilian Amazon. A total of 114 leprosy patients and 71 household contacts were included in this study. Genotyping was performed using TaqMan Open Array Genotyping. Ancestry-informative markers were used to estimate individual proportions of case and control groups. The SNP rs2505901 (pre-miR938) was associated with protection against the development of paucibacillary leprosy, while the SNPs rs639174 (DROSHA), rs636832 (AGO1), and rs4143815 (miR570) were associated with protection against the development of multibacillary leprosy. In contrast, the SNPs rs10739971 (pri-let-7a1), rs12904 (miR200C), and rs2168518 (miR4513) are associated with the development of the paucibacillary leprosy. The rs10739971 (pri-let-7a1) polymorphism was associated with the development of leprosy, while rs2910164 (miR146A) and rs10035440 (DROSHA) was significantly associated with an increased risk of developing multibacillary leprosy.

In silico designing of a recombinant multi-epitope antigen for leprosy diagnosis

BACKGROUND

Leprosy is caused by Mycobacterium leprae and Mycobacterium lepromatosis. Most of the affected population lives in low-income countries and may take up to 10 years to show any clinical signs, which is how physicians diagnose it. However, due to progressive cell damage, early diagnosis is very important. The best way to confirm leprosy is through bacilloscopic, which only confirms the diagnosis and has low accuracy or PCR, that requires specialized operators and is expensive. Since the bacteria are fastidious and do not grow in any culture media, therefore, diagnosing leprosy in the lab is still a challenge. In this concern, a recombinant multi-epitope protein can be a beneficial strategy in the management of the diagnosis, as diverse immunogenic epitopes are precisely selected to detect specific antibodies. Therefore, the purposes of the present study were to select immunogenic epitopes from different relevant proteins, with immunogenic properties, and then to construct a recombinant multi-epitope protein that accuses the presence of the antibodies in the early stages of the disease, making it more than appropriate to be applied as a diagnostic tool.

RESULTS

We selected 22 common proteins from both species and, using bioinformatics tools, predicted B and T cell epitopes. After multiple filtering and analyzing, we ended up with 29 epitopes {MHC-I (total 18) and MHC-II (total 11)} from 10 proteins, which were then merged into one construct. Its secondary and tertiary structures were also predicted and refined to comprise the amino acid residues in the best conformation possible. The multi-epitope protein construct was stable, non-host homologous, non-allergic, non-toxic, and elicit humoral and cellular responses. It has conformational B cell epitopes and potential to elicit IFN-γ, IL-4, and IL-10 secretion.

CONCLUSIONS

This novel recombinant multi-epitope protein constructed using the common epitopes from M. leprae and M. lepromatosis has a huge immunological potential, is stable, and can be lyophilized to be used in ELISA plates or even in biosensors, which are user-friendly diagnosis tools, facilitating translation into human sample tests.

Chromoblastomycosis-Leprosy Co-Infection in Central West Brazil. Presentation of Three Cases and Literature Review

Chromoblastomycosis and leprosy are chronic diseases with high prevalence in tropical and subtropical regions. Brazil is one of the countries with the highest incidence and prevalence for both diseases, however, reports of co-infections are scarce. The aim of this study was to describe three cases of chromoblastomycosis-leprosy co-infection in patients from Mato Grosso state, Brazil. A review of chromoblastomycosis-leprosy co-infection was performed of English, Portuguese and Spanish publications in LILACS, SciELO, PubMed and Web of Science databases using the descriptors (chromoblastomycosis OR cromoblastomicose OR cromoblastomicosis) AND (leprosy OR hanseníase OR lepra), without time period delimitation. Nineteen cases were included, 16 cases were published in 11 articles, plus the three cases reported in the current study. Most reported coninfection cases came from Brazil. Majority of the patients were male with a mean age of 52.2 years. Farmer was the main occupational activity reported. In 12 patients, the clinical signs and symptoms of leprosy started first. No contacts with patients affected by leprosy, armadillos or history of injuries at the anatomical site of chromoblastomycosis lesions were reported. Five leprosy patients who received steroid treatment for leprosy reactions or neuropathies, were diagnosed with chromoblastomycosis during immunosuppressive therapy. Four cases (21.1%) were reported among the elderly patients. Co-infections in patients with chromoblastomycosis or leprosy are uncommon, but the possibility should always be considered, especially if the patient is undergoing immunosuppressive treatment or is elder.

Can Leprosy Reaction States Mimic Symptoms of Fibromyalgia? A Cross-Sectional Analytical Study

Leprosy causes significant pain in affected patients, especially those experiencing reactional states. Fibromyalgia is characterized by widespread pain and is often accompanied by fatigue. Confusion between the clinical manifestations of fibromyalgia and those of leprosy reactions is possible at the primary care level, the first contact with the health system in most cases. We aimed to determine whether the presence of leprosy reactional states is related to the development of signs and symptoms included in the case definition of fibromyalgia and establish recommendations for obtaining the correct diagnosis. We performed a cross-sectional study in which the main independent variable was the presence of any leprosy reactional state and the primary dependent variable was the diagnosis of fibromyalgia according to the 2016 Revisions of the 2010/2011Fibromyalgia Provisional Criteria of the American College of Rheumatology. Forty-three patients were included in the study. Twenty-eight (65.12%) patients had a type I reactional state, only 1 (2.33%) had an isolated type II reactional state, and 5 (11.63%) had both type I and type II reactional states. Only 2 patients who suffered from cooccurring type I and II reactional states obtained sufficient scores for the diagnosis of fibromyalgia. Although diffuse pain was common in leprosy patients, none of the types of reactional states were associated with a higher frequency of criteria for fibromyalgia. We can conclude that a leprosy reactional state is probably not a risk factor for fibromyalgia but can act as a confounder, as tender points may be similar in both diagnoses. In patients diagnosed with fibromyalgia, leprosy must be considered in the differential diagnosis in endemic regions.

Leprosy: clinical and immunopathological characteristics

Leprosy, a disease caused by Mycobacterium leprae, has polymorphic neurocutaneous manifestations strongly correlated with the host immune response. Peripheral neural damage can lead to sensory and motor losses, as well as deformities of the hands and feet. Both innate and acquired immune responses are involved, but the disease has been classically described along a Th1/Th2 spectrum, where the Th1 pole corresponds to the more limited presentations and the Th2 to the multibacillary ones. The aim of this review is to discuss this dichotomy in light of the current knowledge of the cytokines, T helper subpopulations, and regulatory T cells involved in each presentation of leprosy. The text will also address leprosy reactions related to increased inflammatory activity in both limited and multibacillary presentations, leading to exacerbation of chronic signs and symptoms and/or the development of new ones. Despite the efforts of many research groups around the world, there is no standardized serological test/biological marker for diagnosis so far, even in endemic areas, which could contribute to the eradication of leprosy.

Presenting symptoms of leprosy at diagnosis: Clinical evidence from a cross-sectional, population-based study

Background

Leprosy is associated with different dermatologic and neurologic manifestations within a wide clinical spectrum, causing a great diagnostic challenge. Therefore, we aimed to examine associations between common presenting symptoms of leprosy and stage at diagnosis.

Methodology/Principal findings

In this cross-sectional study, we analyzed population-level data from the Leprosy Management Information System (LEPMIS) in Yunnan, China, from 2010–2020 and enrolled patients with newly detected leprosy. The data of 2125 newly detected leprosy patients, with 5000 symptoms, were analyzed. Numbness (828/5000, 16.56%), erythema (802/5000, 16.04%), Painless nor pruritic skin lesions (651/5000, 13.02%), eyebrow hair loss (467/5000, 9.34%), and tubercles (442/5000, 8.84%) were common symptoms of leprosy. The symptoms related to skin (1935/2533, 76.39%) and leprosy reaction (279/297, 93.94%) were mainly existed in MB group. While the symptoms related to disability (263/316, 83.49%), clinical feature (38/56, 69.09%), and facial features (19/23, 82.61%) were predominantly presented in delayed diagnostic group. Despite low proportions, formic sensation (99/5000, 1.98%), pain (92/5000, 1.84%), pruritus (56/5000, 1.12%), finger contracture (109/5000, 2.18%), muscle atrophy (71/5000, 1.42%), and motor dysfunction (18/5000, 0.36%) were reported during the diagnosis of leprosy. The proportions of skin, skin and nerve, and nerve symptoms as initial symptoms were 33.25%, 44.95%, and 21.80% and as only symptoms were 28.66%, 57.81%, and 13.91%, respectively. In those with physical disability, nerve symptoms were the most frequent symptoms (57.65% and 65.36% for the initial and only symptoms, respectively) compared with skin and skin and nerve symptoms. In the delayed diagnosis group, nerve symptoms were the most frequent symptoms (15.73% and 17.25%) and were associated with the longest diagnostic intervals (mean±SD: 38.88±46.02 and 40.35±49.36 months for initial and only symptoms, respectively) when compared with skin and skin and nerve symptoms.

Conclusions

Understanding the nature of presenting symptoms and developing symptom awareness campaigns would improve the level of leprosy awareness in the community. As nerve symptoms were related to a higher proportion of physical disability and longer diagnosis interval, we should increase awareness about nerve symptoms. Individuals with nerve symptoms should be considered the target group. Neurology outpatient visits may provide potential screening opportunities, and holding focused training for specialized neurology medical staff would enhance the capacity of the health system to recognize leprosy early.

Early diagnosis is key in leprosy control; however, the diagnosis of leprosy is still challenging. In this study, we reviewed the common and rare symptoms of leprosy. Numbness, erythema, painless nor pruritic skin lesions, eyebrow hair loss, and tubercles were common symptoms of leprosy. Despite low proportions, formic sensation, pain, pruritus, finger contracture, muscle atrophy, and motor dysfunction were also reported by leprosy patients. As initial symptoms at symptom onset and only symptoms at diagnosis, nerve symptoms were associated with a greater degree of physical disability and a longer diagnosis interval than skin and skin and nerve symptoms. Understanding the presenting symptoms in detail would improve the level of leprosy awareness in the community. Increasing awareness of nerve symptoms, focusing on individuals with nerve symptoms at neurology outpatient visits, and holding focused training for medical staff specializing in neurology would enhance the capacity of the health system to recognize leprosy early.

Identification of sensitive indicators in immune response for leprosy affected patients: An observational clinical study of safety and immunogenicity of influenza vaccine

ABSTRACT

Cured leprosy patients have special physical conditions, which could pose challenges for safety and immunogenicity after immunization. We performed an observational clinical study aimed to identify the safety and immunogenicity of influenza vaccine in cured leprosy patients. A total of 65 participants from a leprosarium were recruited into leprosy cured group or control group, and received a 0.5 ml dose of the inactivated split-virion trivalent influenza vaccine and a follow-up 28 days proactive observation of any adverse events. Hemagglutination and hemagglutination inhibition test was performed to evaluate serum antibody titer, flow cytometry was conducted to screen of cytokines level. The total rate of reactogenicity was 0.0% [0/41] in leprosy cured group and 37.5% [9/24] in control group. The seroconversion rate for H1N1 was difference between leprosy cured group and control group (41.83% vs 79.17%, P = .0082), but not for H3N2 (34.25% vs 50.00%, P = .4468). At day 0, leprosy cured group have relatively high concentration of interleukin-6, interleukin-10, tumor necrosis factor, interferon-γ, and interleukin-17 compared to control group. The interleukin-2 concentration increased 2 weeks after vaccination compared to pre-vaccination in leprosy cured group, but declined in control group (0.92 pg/ml vs -0.02 pg/ml, P = .0147). Leprosy cured group showed a more rapid down-regulation of interleukin-6 when influenza virus was challenged compared to control group (-144.38 pg/ml vs -11.52 pg/ml, P < .0001). Subgroup analysis revealed that the immunization administration declined interleukin-17 concentration in Tuberculoid type subgroup, but not in Lepromatous type subgroup or control group. Clinically cured leprosy patients are relatively safe for influenza vaccine. Leprosy cured patient have immune deficit in producing antibody. Interleukin-6 and interleukin-17 were 2 sensitive indicators in immune response for leprosy affected patients. The identification of indicators might be help management of leprosy and used as predictive markers in leprosy early symptom monitoring.

Potential Role of CXCL10 in Monitoring Response to Treatment in Leprosy Patients

The treatment of multibacillary cases of leprosy with multidrug therapy (MDT) comprises 12 doses of a combination of rifampicin, dapsone and clofazimine. Previous studies have described the immunological phenotypic pattern in skin lesions in multibacillary patients. Here, we evaluated the effect of MDT on skin cell phenotype and on the Mycobacterium leprae-specific immune response. An analysis of skin cell phenotype demonstrated a significant decrease in MRS1 (SR-A), CXCL10 (IP-10) and IFNG (IFN-γ) gene and protein expression after MDT release. Patients were randomized according to whether they experienced a reduction in bacillary load after MDT. A reduction in CXCL10 (IP-10) in sera was associated with the absence of a reduction in the bacillary load at release. Although IFN-γ production in response to M. leprae was not affected by MDT, CXCL10 (IP-10) levels in response to M. leprae increased in cells from patients who experienced a reduction in bacillary load after treatment. Together, our results suggest that CXCL10 (IP-10) may be a good marker for monitoring treatment efficacy in multibacillary patients.

Functional Expression, Purification and Identification of Interaction Partners of PACRG

PACRG (Parkin co-regulated gene) shares a bi-directional promoter with the Parkinson’s disease-associated gene Parkin, but the physiological roles of PACRG have not yet been fully elucidated. Recombinant expression methods are indispensable for protein structural and functional studies. In this study, the coding region of PACRG was cloned to a conventional vector pQE80L, as well as two cold-shock vectors pCold II and pCold-GST, respectively. The constructs were transformed into Escherichia coli (DE3), and the target proteins were overexpressed. The results showed that the cold-shock vectors are more suitable for PACRG expression. The soluble recombinant proteins were purified with Ni²⁺ chelating column, glutathione S-transferase (GST) affinity chromatography and gel filtration. His₆ pull down assay and LC-MS/MS were carried out for identification of PACRG-binding proteins in HEK293T cell lysates, and a total number of 74 proteins were identified as potential interaction partners of PACRG. GO (Gene ontology) enrichment analysis (FunRich) of the 74 proteins revealed multiple molecular functions and biological processes. The highest proportion of the 74 proteins functioned as transcription regulator and transcription factor activity, suggesting that PACRG may play important roles in regulation of gene transcription.