肿瘤移植裸鼠粪类圆线虫感染病原和分子诊断

目的：肿瘤移植裸鼠粪类圆虫病诊断。方法肿瘤移植裸鼠的尸体解剖显微镜检查发现类圆线虫作形态学鉴定并采用二重PCR进行分子诊断。结果尸检发现肿瘤移植裸鼠样本中出现大量粪类圆线虫,初步确诊粪类圆线虫病,二重PCR检出样本中粪类圆线虫特定DNA进一步确诊。结论防止这种严重后果是早期诊断。肿瘤移植受体和供体应进行寄生虫感染包括类圆线虫病筛查。本研究第一个广泛报道了肿瘤移植裸鼠粪类圆虫病诊断。     

Phylogenetic Positioning of a Strongyloides stercoralis Isolate Recovered from a Korean Patient and Comparison with Other Asian Isolates

Strongyloidiasis is caused by Strongyloides stercoralis and is one of the most neglected tropical diseases in tropical and subtropical regions. Although several strongyloidiasis cases have been reported in Korea, genetic analysis of Korean isolates is still incomplete. In this study, a parasite was isolated from a 61-year-old man diagnosed with strongyloidiasis during the treatment of lymphoma on his retroperitoneal lymph node. Diffuse symmetric wall thickening from the ascending to descending colon and a nematode-infected intestine was observed following microscopic examination. Genomic DNA was isolated from a patient tissue block, and S. stercoralis was identified by PCR and sequencing (18S rDNA). In order to determine phylogenetic location of a Korean isolate (named KS1), we analyzed cox1 gene (500-bp) and compared it with that from 47 previous S. stercoralis isolates (28 human isolates and 19 canid isolates) from Asian countries. Our results showed that phylogenetic tree could clearly be divided into 5 different groups according to hosts and regions. KS1 was most closely related with the Chinese isolates in terms of genetic distance.     

A case of Strongyloides stercoralis infection.

Strongyloidiasis has been recognized as one of the life-threatening parasitic infections in the immunocompromised patients. We report an intestinal infection case of Strongyloides stercoralis in a 61-year-old man. Rhabditiform larvae were detected in the stool examination and developed to filariform larvae having a notched tail through the Harada-Mori filter paper culture. The patient received five courses of albendazole therapy but not cured of strongyloidiasis.     

Seropositivity Rates of Strongyloides stercoralis Antibody in the Southeastern Region of Republic of Korea: A Single-Center Retrospective Study

Strongyloides stercoralis infection is not endemic in the Republic of Korea (Korea) with a positivity rate of <1% in stool examination. However, there is a risk of hyperinfection in immunosuppressed individuals. It is necessary to determine the seropositivity of S. stercoralis antibodies in Korea. This study investigated the seropositivity of S. stercoralis antibodies in the southeastern area of Korea. From January 2019 to June 2021, serum samples were collected from participants who visited the study center in the southeastern region of Korea for routine health check-ups. We determined serum levels of specific anti-Strongyloides IgG antibodies in 834 samples by enzyme-linked immunosorbent assay. We observed that 92 samples (11.0%) tested showed a positive response. The age of the participants was 51±10.7 years, and 43.4% of them were men. The antibody positivity rate based on the location of the participants’ residence were 12.3% (Gyoungsangnam-do), 10.2% (Busan), and 10.1% (Ulsan), respectively. Total eosinophil count was associated with positive test results (154.8±152.0 per mm³ versus 202.1±178.9 per mm³, P=0.006). Logistic regression analysis revealed that blood eosinophil count, age above 50 years, and residence in Sacheon were factors associated with the positive status of S. stercoralis antibody. Our finding suggests that it is necessary to test for S. stercoralis in actual clinical settings in Korea.     

Standardisation of Western blotting to detect HTLV-1 antibodies synthesised in the central nervous system of HAM/TSP patients

Intrathecal synthesis of human T-lymphotropic virus type 1 (HTLV-1) antibodies (Abs) represents conclusive evidence of a specific immune response in the central nervous system of HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients. Western blotting (WB) for HTLV Abs in serum is a confirmatory test for HTLV-1 infection. The aim of this study was to standardise the Western blot to demonstrate the intrathecal pattern of Abs against HTLV-1 proteins in HAM/TSP patients. Paired cerebrospinal fluid (CSF) and serum samples were selected from 20 patients with definite HAM/TSP, 19 HTLV-1 seronegative patients and two HTLV-1 patients without definite HAM/TSP. The presence of reactive bands of greater intensity in the CSF compared to serum (or bands in only the CSF) indicated the intrathecal synthesis of anti-HTLV-1 Abs. All definite HAM/TSP patients presented with an intrathecal synthesis of anti-HTLV-1 Abs; these Abs were not detected in the control patients. The most frequent intrathecal targets of anti-HTLV-1 Abs were GD21, rgp46-I and p24 and, to a lesser extent, p19, p26, p28, p32, p36, p53 gp21 and gp46. The intrathecal immune response against env (GD21 and rgp46-I) and gag (p24) proteins represents the most important humoral pattern in HAM/TSP. This response may be used as a diagnostic marker, considering the frequent association of intrathecal anti-HTLV-1 Ab synthesis with HAM/TSP and the pathogenesis of this neurological disease.     

Regulatory T Cell Expansion in HTLV-1 and Strongyloidiasis Co-infection Is Associated with Reduced IL-5 Responses to Strongyloides stercoralis Antigen

Background

Human strongyloidiasis varies from a chronic but limited infection in normal hosts to hyperinfection in patients treated with corticosteroids or with HTLV-1 co-infection. Regulatory T cells dampen immune responses to infections. How human strongyloidiasis is controlled and how HTLV-1 infection affects this control are not clear. We hypothesize that HTLV-1 leads to dissemination of Strongyloides stercoralis infection by augmenting regulatory T cell numbers, which in turn down regulate the immune response to the parasite.

Objective

To measure peripheral blood T regulatory cells and Strongyloides stercoralis larval antigen-specific cytokine responses in strongyloidiasis patients with or without HTLV-1 co-infection.

Methods

Peripheral blood mononuclear cells (PBMCs) were isolated from newly diagnosed strongyloidiasis patients with or without HTLV-1 co-infection. Regulatory T cells were characterized by flow cytometry using intracellular staining for CD4, CD25 and FoxP3. PBMCs were also cultured with and without Strongyloides larval antigens. Supernatants were analyzed for IL-5 production.

Results

Patients with HTLV-1 and Strongyloides co-infection had higher parasite burdens. Eosinophil counts were decreased in the HTLV-1 and Strongyloides co-infected subjects compared to strongyloidiasis-only patients (70.0 vs. 502.5 cells/mm³, p = 0.09, Mann-Whitney test). The proportion of regulatory T cells was increased in HTLV-1 positive subjects co-infected with strongyloidiasis compared to patients with only strongyloidiasis or asymptomatic HTLV-1 carriers (median = 17.9% vs. 4.3% vs. 5.9 p<0.05, One-way ANOVA). Strongyloides antigen-specific IL-5 responses were reduced in strongyloidiasis/HTLV-1 co-infected patients (5.0 vs. 187.5 pg/ml, p = 0.03, Mann-Whitney test). Reduced IL-5 responses and eosinophil counts were inversely correlated to the number of CD4+CD25+FoxP3+ cells.

Conclusions

Regulatory T cell counts are increased in patients with HTLV-1 and Strongyloides stercoralis co-infection and correlate with both low circulating eosinophil counts and reduced antigen-driven IL-5 production. These findings suggest a role for regulatory T cells in susceptibility to Strongyloides hyperinfection.     

Combinatorial screening algorithm to engineer multiepitope subunit vaccine targeting human T-lymphotropic virus-1 infection

Human T-lymphotropic virus (HTLV), the first human retrovirus has been discovered which is known to cause the age-old assassinating disease HTLV-1 associated myelopathy. Cancer caused by this virus is adult T cell leukemia/lymphoma which targets 10–20 million throughout the world. The effect of this virus extends to the fact that it causes chronic disease to the spinal cord resulting in loss of sensation and further causes blood cancer. So, to overcome the complications, we designed a subunit vaccine by the assimilation of B-cell, cytotoxic T-lymphocyte , and helper T-lymphocyte epitopes. The epitopes were joined together along with adjuvant and linkers and a vaccine was fabricated which was further subjected to 3D modeling. The physiochemical properties, allergenicity, and antigenicity were evaluated. Molecular docking and dynamics were performed with the obtained 3D model against toll like receptor (TLR-3) immune receptor. Lastly, in silico cloning was performed to ensure the expression of the designed vaccine in pET28a(+) expression vector. The future prospects of the study entailed the in vitro and in vivo experimental analysis for evaluating the immune response of the designed vaccine construct.     

Molecular diagnosis of strongyloidiasis in tropical areas: a comparison of conventional and real-time polymerase chain reaction with parasitological methods

This study aimed to evaluate the use of conventional polymerase chain reaction (cPCR) and real-time quantitative PCR (qPCR) in the diagnosis of human strongyloidiasis from stool samples in tropical areas. Stool samples were collected from individuals and were determined to be positive for Strongyloides stercoralis (group I), negative for S. stercoralis (group II) and positive for other enteroparasite species (group III). DNA specific to S. stercoralis was found in 76.7% of group I samples by cPCR and in 90% of group I samples by qPCR. The results show that molecular methods can be used as alternative tools for detecting S. stercoralis in human stool samples in tropical areas.     

人类T淋巴细胞白血病病毒流行区无偿献血人群筛查研究

人类T淋巴细胞白血病病毒(human T-lym-photropic virus,HTLV)是最早发现的人类逆转录病毒,分为I型和II型。HTLV感染后,会在人体内长期存在,潜伏期长达20年以上,并在多年后引起白血病或下肢瘫痪等致死性或致残性疾病,迄今有效的治疗药物和预防性疫苗仍未研制成功[1]。因此,唯一积极的控制办法就是及时发现HTLV感染者,并采取措施切断其传播途径。由于HTLV可经血传播,日本、美国、澳大利亚、法国及其它一些国家和地区已将其列为献血员必检项目之一,但我国各地均一直未开展此项目。自1986年以来,我国先后在多个省、市发现了HTLV感染…     

HTLV-1 and apoptosis: role in cellular transformation and recent advances in therapeutic approaches

A universal cellular defense mechanism against viral invasion is the elimination of infected cells through apoptotic cell death. To counteract host defenses many viruses have evolved complex apoptosis evasion strategies. The oncogenic human retrovirus HTLV-1 is the etiological agent of adult-T-cell leukemia/lymphoma (ATLL) and the neurodegenerative disease known as HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The poor prognosis in HTLV-1-induced ATLL is linked to the resistance of neoplastic T cells against conventional therapies and the immuno-compromised state of patients. Nevertheless, several studies have shown that the apoptotic pathway is largely intact and can be reactivated in ATLL tumor cells to induce specific killing. A better understanding of the molecular mechanisms employed by HTLV-1 to counteract cellular death pathways remains an important challenge for future therapies and the treatment of HTLV-1-associated diseases.     

Strongyloides stercoralis: oral transfer of parasitic adult worms produces infection in mice and infection with subsequent autoinfection in gerbils.

Oral transfer of parasitic adult Strongyloides stercoralis produced patent infections in gerbils, C57BL/6J and SCID mice. In gerbils receiving adult worms, 7.3% of the transferred worms established and autoinfective L3 were found beginning on day 5 post-transfer, with peak numbers seen on days 6 and 7 post-transfer and few seen by 9 days post-transfer. These results suggest that development of autoinfective L3 in the gerbil is limited by the immune response of the host. When given orally to mice, between 7.2% (C57BL/6J) and 19.5% (SCID) of the adult worms established. These levels are higher than those previously obtained by the subcutaneous infection of SCID mice with infective larvae. No autoinfective larvae were found in infected mice and the ratio of L1/adult worms was small compared with that seen in gerbils. Thus, mice infected orally can be used as a model to study the interaction between the adult worm and the host, and since autoinfection has not been seen in the murine model, as developed to date, orally infected mice may be useful as a model to study mechanisms preventing autoinfection.     

季节性流感病毒与其他病原混合或继发感染的研究进展与思考

流感病毒包括甲(A)、乙(B)、丙(C)和丁(D)四种型。人流行性感冒是由甲型和乙型季节性流感病毒引起的一种急性呼吸道传染病。流感病毒感染患者主要表现出呼吸道症状,严重时可以导致肺炎。此外,与其他病毒、细菌和支原体等病原体混合或继发感染时,会增加流感患者的重症率和死亡率。近几年,流感病毒与其他病原协同感染的病例有增加趋势。本文归纳总结了流感病毒与其他病原混合及继发感染的研究现状,希望为流感病毒复杂感染情况的临床诊断和治疗方案的制定提供线索。     

Strongyloides stercoralis and HTLV-1 coinfection in CD34+ cord blood stem cell humanized mice: Alteration of cytokine responses and enhancement of larval growth

Viral and parasitic coinfections are known to lead to both enhanced disease progression and altered disease states. HTLV-1 and Strongyloides stercoralis are co-endemic throughout much of their worldwide ranges resulting in a significant incidence of coinfection. Independently, HTLV-1 induces a Th1 response and S. stercoralis infection induces a Th2 response. However, coinfection with the two pathogens has been associated with the development of S. stercoralis hyperinfection and an alteration of the Th1/Th2 balance. In this study, a model of HTLV-1 and S. stercoralis coinfection in CD34⁺ umbilical cord blood hematopoietic stem cell engrafted humanized mice was established. An increased level of mortality was observed in the HTLV-1 and coinfected animals when compared to the S. stercoralis infected group. The mortality was not correlated with proviral loads or total viral RNA. Analysis of cytokine profiles showed a distinct shift towards Th1 responses in HTLV-1 infected animals, a shift towards Th2 cytokines in S. stercoralis infected animals and elevated TNF-α responses in coinfected animals. HTLV-1 infected and coinfection groups showed a significant, yet non-clonal expansion of the CD4⁺CD25⁺ T-cell population. Numbers of worms in the coinfection group did not differ from those of the S. stercoralis infected group and no autoinfective larvae were found. However, infective larvae recovered from the coinfection group showed an enhancement in growth, as was seen in mice with S. stercoralis hyperinfection caused by treatment with steroids. Humanized mice coinfected with S. stercoralis and HTLV-1 demonstrate features associated with human infection with these pathogens and provide a unique opportunity to study the interaction between these two infections in vivo in the context of human immune cells.     

GB virus C infection in Indonesian HIV‐positive patients

GB virus C (GBV‐C), a human virus of the Flaviviridae family that is structurally and epidemiologically closest to hepatitis C virus (HCV), has been reported to confer beneficial outcomes in HIV‐positive patients. However, the prevalence of GBV‐C in HIV‐positive individuals in Indonesia is unknown. Since GBV‐C is more prevalent in anti‐HCV positive patients than in anti‐HCV negative subjects, transmission of GBV‐C and HCV could be by the same method. This study examined the prevalence and molecular characteristics of GBV‐C infection in HIV patients in Yogyakarta, Indonesia. The prevalence of GBV‐C among HIV patients (n = 125, median age 31 years) based on the 5′UTR region was 111/125 (88.8%), including 39/48 (81.3%) and 72/77 (93.5%) HIV‐infected patients with and without HCV infection, respectively. GBV‐C isolates were of genotype 2a, 3 and 6 in 58.3%, 12.6% and 28.4% of patients, respectively. Patients with genotype 3 were significantly younger than those with genotypes 2a or 6 (P = 0.001 and P = 0.012, respectively). Genotypes 3 and 6 were significantly associated with injection drug use (P = 0.004 and P = 0.002, respectively) and HCV co‐infection (P < 0.001 for both genotypes), indicating a shared transmission route with HCV. In conclusion, the prevalence of GBV‐C among HIV‐positive patients in Indonesia is high, and three genotypes were detected, namely genotype 2a, 3 and 6.     

Human avian influenza A (H5N1) virus infection in China

Highly pathogenic influenza A (H5N1) virus causes a widespread poultry deaths worldwide. The first human H5N1 infected case was reported in Hong Kong Special Administrative Region of China in 1997. Since then, the virus re-emerged in 2003 and continues to infect people worldwide. Currently, over 400 human infections have been reported in more than 15 countries and mortality rate is greater than 60%. H5N1 viruses still pose a potential pandemic threat in the future because of the continuing global spread and evolution. Here, we summarize the epidemiological, clinical and virological characteristics of human H5N1 infection in China monitored and identified by our national surveillance systems. Chinese Nature Science Foundation Key Project (Grant No. 30599433), Chinese Basic Science Research Program (973)Key Project (Grant No. 2005CB523006)     

Immunological signature of the different clinical stages of the HTLV-1 infection: establishing serum biomarkers for HTLV-1-associated disease morbidity

Abstract

This study aimed at establishing the immunological signature and an algorithm for clinical management of the different clinical stages of the HTLV-1-infection based on serum biomarkers. A panel of serum biomarkers was evaluated by four sets of innovative/non-conventional data analysis approaches in samples from 87 HTLV-1 patients: asymptomatic carriers (AC), putative HTLV-1 associated myelopathy/tropical spastic paraparesis (pHAM/TSP) and HAM/TSP. The analysis of cumulative curves and molecular signatures pointed out that HAM/TSP presented a pro-inflammatory profile mediated by CXCL10/LTB-4/IL-6/TNF-α/IFN-γ, counterbalanced by IL-4/IL-10. The analysis of biomarker networks showed that AC presented a strongly intertwined pro-inflammatory/regulatory net with IL-4/IL-10 playing a central role, while HAM/TSP exhibited overall immune response toward a predominant pro-inflammatory profile. At last, the classification and regression trees proposed for clinical practice allowed for the construction of an algorithm to discriminate AC, pHAM and HAM/TSP patients with the elected biomarkers: IFN-γ, TNF-α, IL-10, IL-6, IL-4 and CysLT. These findings reveal a complex interaction among chemokine/leukotriene/cytokine in HTLV-1 infection and suggest the use of the selected but combined biomarkers for the follow-up/diagnosis of disease morbidity of HTLV-1-infected individuals.