Pharmacological effects of anti-melanoma DC vaccine sensitized by fusion proteins of G3G6 and HST1 / 中国药科大学学报

@#This study aimed to investigate the effects of fusion proteins GnRH-GRP(G3G6)and HSP65-STEAP1(HST1)on dendritic cells(DC)and the sensitization of DCs to B16F10 melanoma. The fusion proteins G3G6 and HST1 were obtained using the previous engineering strains in our laboratory. Group by unsensitized DC(US-DC), the G3G6 fusion protein sensitized DC, the HST1 fusion protein sensitized DC(HST1-DC)and the combined sensitized DC(GH-DC), the mouse bone marrow-derived DCs were sensitized with fusion protein to obtain the fusion protein sensitized DC vaccines. B16F10 melanoma cells were transplanted into C57BL/6J male mice to construct a melanoma model(1×106 cells per mouse), and DC vaccine was injected for treatment. The antitumor efficacy of DC vaccine was explored by in vitro and in vivo experiments. Flow cytometry analysis showed that the fusion protein can effectively stimulate DC into differentiation and maturation; in the animal experiment, the inhibition rate of melanoma treated with G3G6-DC was 35. 75%, that of HST1-DC group and combination group were 34. 03% and 55. 74%. It was initially proved that both G3G6-DC and HST1-DC can effectively inhibit the growth of transplanted tumors of melanoma B16F10 cells in mice, and the combination therapy is superior to the single therapy.

Effects of Yangyin Recipe on imbalance of Th17 and Treg cells in ApoE-/- mice under HSP65 attack / 中草药

Objective To investigate the effects of Yangyin Recipe on atherosclerosis (AS) lesions, helper T cells 17 (Th17), and regulatory T cells (Treg) in apolipoprotein E knockout (ApoE-/-) mice under the heat shock protein (HSP) 65 attack, and explore the potential mechanisms. Methods ApoE-/- mice were fed with normal and high-fat diets respectively, and injected with sterile PBS or HSP65. Simvastatin was used as the positive drug to study the effects of Yangyin Recipe on blood lipids, plaques, Th17/Treg cells and related inflammation indicators in AS model mice. Drugs were all intragastric administrated with equal volume of normal saline as a control. Serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) were detected by esterase method; The area of aortic plaque was determined by oil red O staining; The amounts of IL-17A+CD4+ Th17 and Foxp3+CD25+CD4+ Treg cells in anticoagulated blood were determined by flow cytometry; Serum IL-6, IL-17, IL-2, TGF-β, and IL-10 were determined by ELISA; mRNA expression of Stat3, Stat5a, Foxp3 in spleens and Stat3, Stat5a in aortas were detected by qPCR; Protein expression of phosphorylated STAT3 (pSTAT3), phosphorylated STAT5 (pSTAT5), FOXP3 in spleen, and pSTAT3 in aortas were determined by Western blotting. Results Under the influence of Yangyin Recipe, serum TC, TG, LDL levels decreased (P < 0.01), and HDL increased (P < 0.05); Aortic plaque area decreased remarkably (P < 0.01); IL-17A+CD4+Th17 cells in peripheral blood decreased (P < 0.05), Foxp3+CD25+CD4+ Treg increased (P < 0.05), and Th17/Treg ratio decreased drastically (P < 0.01); Serum IL-6 decreased (P < 0.05), IL-2 (P < 0.01), TGF-β and IL-10 (P < 0.05) increased; Protein levels of pSTAT3 in spleens decreased (P < 0.01), but pSTAT5 (P < 0.01) and FOXP3 (P < 0.05) increased; Aortic Stat3 mRNA (P < 0.01) and pSTAT3 (P < 0.05) protein decreased. Conclusion Yangyin Recipe can improve hyperlipidemia and AS in ApoE-/- mice during HSP65 attack, and regulate the balance of Th17/Treg in peripheral blood and the secretion of inflammatory factors to improve inflammation, which may be related to attenuate IL-6/pSTAT3 and enhance IL-2/pSTAT5 signaling.

PCR-based identification of Mycobacterium murphy causing Canine Leproid Granuloma Syndrome in Niterói, southeast Brazil - case report / Identificação baseada em PCR de Mycobacterium murphy causando Síndrome do Granuloma Lepróide Canino em Niterói, sudeste do Brasil ˗ Relato de Caso

Canine Leproid Granuloma Syndrome (CLGS), also known as canine leprosy, is a cutaneous nodular infectious disease caused by Mycobacterium sp.. Despite being reported worldwide, it is still quite unknown and underdiagnosed. Diagnosis may be achieved by cytopathology or histopathology of skin lesions, but identification of the infectious agent is complex, since bacterial in vitro growth is not possible, relying upon molecular techniques such as PCR to confirm Mycobacterium DNA in the sample. We report a CLGS case in Niteroi, Rio de Janeiro state, Brazil, diagnosed by cytopathology and submitted to molecular identification of the agent. PCR amplification of hsp65 gene was performed and revealed 100% genetic homology to M. murphy strain. This is the first CLGS report with molecular identification in Rio de Janeiro state, and this finding should raise awareness about CLGS as a differential diagnosis among granulomatous skin diseases in this region.(AU)

A síndrome de granuloma leproide canino (SGLC), também conhecida como lepra canina, é uma doença infecciosa cutânea nodular causada por Mycobacterium sp. Apesar de ser relatada mundialmente, ainda é bastante desconhecida e subdiagnosticada. O diagnóstico pode ser conseguido por citopatologia ou histopatologia de lesões cutâneas, mas a identificação do agente infeccioso é complexa, uma vez que o crescimento in vitro bacteriano não é possível, dependendo de técnicas moleculares como a PCR para confirmar o DNA de Mycobacterium na amostra. Relatou-se um caso da SGLC em Niterói, estado do Rio de Janeiro, Brasil, diagnosticado por citopatologia e submetido à identificação molecular do agente. Foi realizada amplificação por PCR do gene hsp65, que revelou 100% de homologia genética com a cepa M. murphy. Este é o primeiro relato da SGLC com identificação molecular no estado do Rio de Janeiro, o que mostra a importância de se acrescentar a SGLC ao diagnóstico diferencial das doenças granulomatosas de pele nessa região.(AU)

Prevalence of nontuberculous mycobacteria isolated from pulmonary specimens in Wenzhou during 2014 to 2016 / 中华临床感染病杂志

Objective To investigate the isolation rate, distribution and trend of nontuberculous mycobacteria (NTM) in Wenzhou during 2014 to 2016.Methods Sputum or alveolar lavage specimens of patients with suspected pulmonary tuberculosis were collected for mycobacteria culture from January 2014 to December 2016.Mycobacterium culture positive strains were further identified by gene chip, 16S rRNA and hsp65 gene sequencing.SPSS 19.0 software was used to analyze the data.Results After excluding repetitive strains, 3 295 mycobacteria strains (MTB) were isolated from respiratory specimens, included 3 032 mycobacterium tuberculosis complex strains, 238 NTM strains, 20 Gordon genera strains, 3 Nocardia genera strains and 2 Tsukamurella genera strains.The proportion of NTM among confirmed mycobacteria was 8.5％ (86/1 006), 6.7％ (72/1 079) and 6.8％ (80/1 185) in 2014, 2015 and 2016, respectively (x2 =2.459,P ＞ 0.05).The overall prevalence of NTM was 7.3 ％ (238/3 270).There were 15 species of NTM, and the most common NTM strain was Mycobacterium intracellulare (52.5％,125/238), followed by Mycobacterium abscessus (22.7％, 54/238) and Mycobacterium avium (10.1％, 24/238), other species were only accounted for 14.7％ (35/238).The ranking of Mycobacterium avium went up rapidly from the fifth in 2014 to the second in 2016 (x2 =18.259, P ＜ 0.01), while proportion of Mycobacterium abscess, dropped from 34.9％ (30/86) in 2014 to 17.5％ (14/80) in 2016 (x2 =7.335, P＜0.01).Among patients from whom the NTM strains were isolated, 56.7％ (135/238) were male and most of them were aged 45 years or above (79.8％, 190/238).Conclusions In the past three years, the trend of NTM isolation rate in Wenzhou is steady.The most prevalent NTM species is Mycobacterium intracellulare, followed by Mycobacterium abscessus and Mycobacterium avium.Mycobacterium avium shows a continuously upward trend, while the separation of Mycobacterium abscessus shows a downward trend.

Effects of Mycobacterium tuberculosis HSP65 on Treg/Th17 immune balance in ApoE-knockout mice / 中国药科大学学报

@#To investigate the effects of Mycobacterium tuberculosis heat shock protein 65(HSP65)on Treg/Th17 immune balance in ApoE-knockout(ApoE-/-)mice, ApoE-/- mice with a high-cholesterol diet were immunized with M. tuberculosis HSP65. Sera were obtained for measurement of anti-HSP65 antibodies by ELISA; the effect of administration of different antigens was investigated, respectively, using flow cytometry analysis on the number of CD4+CD25+Foxp3+Tregs and CD4+IL-17+ Th17; the production of cytokines(IL-10, TGF-β1, IL-17 and IL-21)by these cells were determined by ELISA; total plasma cholesterol(TC), triglyceride(TG), high-density lipoprotein cholesterol(HDL-C)and low-density lipoprotein cholesterol(LDL-C)levels were detected by biochemical autoanalyzer. Atherosclerotic lesions were measured by lipid deposition stained with oil red O. The results demonstrated that the levels of anti-HSP65 IgG antibodies were increased significantly in Mycobacterium tuberculosis HSP65-treated ApoE-/- mice, revealed obvious decrease in Treg number, Treg related cytokines(IL-10, TGF-β1)levels and significant increase in Th17 number, Th17 related cytokines(IL-17 and IL-21)levels, the levels of TC, TG, HDL-C and LDL-C did not change between groups, while the atherosclerotic lesions significantly increased. Results indicate that M. tuberculosis HSP65 could interrupt the Th17/Treg immune balance in ApoE-/- mice, suggesting a potential role in the formation and progression of atherosclerosis.

A case of skin infection caused by Mycobacterium szulgai / 中华皮肤科杂志

A 7?year?old girl presented with a plaque on the left side of the face for 4 years. Skin examination revealed a well?marginated circular firm plaque measuring 6 cm × 5 cm in size on the left side of the face with purulent crusts on the surface, which was nontender to palpation. Histopathologic study showed ulceration and necrosis in some areas in the epidermis, diffuse dermal infiltration of lymphocytes, histiocytes and epithelioid cells with the presence of many neutrophilic granulocytes in some regions. Both periodic acid?Schiff(PAS)staining and acid?fast staining were negative. After 25 days of tissue culture, scotochromogenic Mycobacterium colonies grew, and colony smears showed positive acid?fast staining. The sequences of 16S rRNA and hsp65 genes of the fungal isolate showed 100%and 99%homology with those of Mycobacterium szulgai, respectively. After the treatment with rifampicin, isoniazid and ethambutol, the patient′s condition was improved.

B cells expressing IL-10 mRNA modulate memory T cells after DNA-Hsp65 immunization

In DNA vaccines, the gene of interest is cloned into a bacterial plasmid that is engineered to induce protein production for long periods in eukaryotic cells. Previous research has shown that the intramuscular immunization of BALB/c mice with a naked plasmid DNA fragment encoding the Mycobacterium leprae 65-kDa heat-shock protein (pcDNA3-Hsp65) induces protection against M. tuberculosis challenge. A key stage in the protective immune response after immunization is the generation of memory T cells. Previously, we have shown that B cells capture plasmid DNA-Hsp65 and thereby modulate the formation of CD8+ memory T cells after M. tuberculosis challenge in mice. Therefore, clarifying how B cells act as part of the protective immune response after DNA immunization is important for the development of more-effective vaccines. The aim of this study was to investigate the mechanisms by which B cells modulate memory T cells after DNA-Hsp65 immunization. C57BL/6 and BKO mice were injected three times, at 15-day intervals, with 100 µg naked pcDNA-Hsp65 per mouse. Thirty days after immunization, the percentages of effector memory T (TEM) cells (CD4+ and CD8+/CD44high/CD62Llow) and memory CD8+ T cells (CD8+/CD44high/CD62Llow/CD127+) were measured with flow cytometry. Interferon γ, interleukin 12 (IL-12), and IL-10 mRNAs were also quantified in whole spleen cells and purified B cells (CD43−) with real-time qPCR. Our data suggest that a B-cell subpopulation expressing IL-10 downregulated proinflammatory cytokine expression in the spleen, increasing the survival of CD4+ TEM cells and CD8+ TEM/CD127+ cells.

Sternal Osteomyelitis Caused by Gordonia bronchialis after Open-Heart Surgery / 감염과화학요법

We report the case of a deep sternal wound infection with sternal osteomyelitis caused by Gordonia bronchialis after open-heart surgery. The isolate was identified as a G. bronchialis by 16S rRNA and hsp65 gene sequencing, having initially been misidentified as a Rhodococcus by a commercial phenotypic identification system.

Enhanced immune response of a bicistronic DNA vaccine expressing fusion antigen Hsp65-Esat-6 of Mycobacterium Tuberculosis with GM-CSF as a molecular adjuvant

This study aimed to construct a bicistronic DNA vaccine expressing fusion antigen Hsp65-Esat-6 of Mycobacterium tuberculosis with cytokine GM-CSF as a molecular adjuvant (pIRES-Hsp65-ESAT-6-GM-CSF, pIRHEG), and the immune response in mice. C57BL/6 mice were immunized with the recombinant plasmid to detect the titer of antibodies, lymphocyte proliferation, the ratio of CD4+, CD8+T cell and IFN ~ γﻌIL-2 secretion. The titer of antibody, lymphocyte proliferation, the ratio of CD4+T and CD8+T cells and IFN ~ γ, IL-2 secretion of pIRHEG group was significant higher than other recombinant plasmid groups, which significant differed by statistical mean. The bicistronic DNA vaccine could induce an effective immune response in mice and could be used as vital ingredient of a new tuberculosis vaccine candidate.

The First Korean Case of Disseminated Mycetoma Caused by Nocardia pseudobrasiliensis in a Patient on Long-Term Corticosteroid Therapy for the Treatment of Microscopic Polyangiitis

Nocardia pseudobrasiliensis is predominantly associated with invasive infections in immunocompromised patients. We report a case of disseminated mycetoma caused by N. pseudobrasiliensis in a 57-yr-old woman with microscopic polyangiitis, who was treated for 3 months with corticosteroids. The same organism was isolated from mycetoma cultures on the patient's scalp, right arm, and right leg. The phenotypic characteristics of the isolate were consistent with both Nocardia brasiliensis and N. pseudobrasiliensis, i.e., catalase and urease positivity, hydrolysis of esculin, gelatin, casein, hypoxanthine, and tyrosine, but no hydrolysis of xanthine. The isolate was identified as N. pseudobrasiliensis based on 16S rRNA and hsp65 gene sequencing. The patient was treated for 5 days with intravenous ampicillin/sulbactam, at which time both the mycetomas and fever had subsided and discharged on amoxicillin/clavulanate. This case highlights a very rare presentation of mainly cutaneous mycetoma caused by N. pseudobrasiliensis. This is the first reported case of N. pseudobrasiliensis infection in Korea.

The First Korean Case of Disseminated Mycetoma Caused by Nocardia pseudobrasiliensis in a Patient on Long-Term Corticosteroid Therapy for the Treatment of Microscopic Polyangiitis

Nocardia pseudobrasiliensis is predominantly associated with invasive infections in immunocompromised patients. We report a case of disseminated mycetoma caused by N. pseudobrasiliensis in a 57-yr-old woman with microscopic polyangiitis, who was treated for 3 months with corticosteroids. The same organism was isolated from mycetoma cultures on the patient's scalp, right arm, and right leg. The phenotypic characteristics of the isolate were consistent with both Nocardia brasiliensis and N. pseudobrasiliensis, i.e., catalase and urease positivity, hydrolysis of esculin, gelatin, casein, hypoxanthine, and tyrosine, but no hydrolysis of xanthine. The isolate was identified as N. pseudobrasiliensis based on 16S rRNA and hsp65 gene sequencing. The patient was treated for 5 days with intravenous ampicillin/sulbactam, at which time both the mycetomas and fever had subsided and discharged on amoxicillin/clavulanate. This case highlights a very rare presentation of mainly cutaneous mycetoma caused by N. pseudobrasiliensis. This is the first reported case of N. pseudobrasiliensis infection in Korea.

Chronic Pulmonary Disease Due to Mycobacterium monacense Infection: The First Case from Iran

We herein report a case in which the recently characterized species Mycobacterium monacense was isolated from the sputum of an Iranian patient. This case represents the first isolation of M. monacense from Iran. The isolate was identified by conventional and molecular techniques. Our findings show that M. monacense infection is not restricted to developed countries.

Avaliação da segurança e imunogenicidade da vacina candidata ao controle da tuberculose pVAXhsp65 administrada por eletroporação em macacos cynomolgus (Macaca fascicularis) / Evaluation of safety and immunogenicity of the vaccine candidate for tuberculosis control pVAX-hsp65 administered by electroporation in cynomolgus monkeys (macaca fascicularis)

A tuberculose é uma doença infecciosa crônica causada pelo Mycobacterium tuberculosis e foi declarada emergência em saúde pública mundial pela Organização Mundial de Saúde. A tuberculose persiste como um problema de saúde mundial, em parte, porque os indivíduos infectados, muitas vezes, não aderem ao longo tratamento de forma devida. A ampla vacinação com a BCG reduziu a ocorrência das formas mais graves de tuberculose em crianças, porém, a forma adulta pulmonar é responsável pela principal causa de morte no mundo. A validação de novas vacinas para utilização na clínica humana, passa pela necessidade de se testá-las, ainda em fase pré-clínica, em modelo animal que desenvolva e reproduza de forma semelhante a doença humana. Avaliamos, neste estudo, os aspectos referentes à segurança do método de eletroporação e a imunogenicidade da vacina pVAX-hsp65, administrada em 3 doses com intervalo de 1 mês cada, em macacos cynomolgusForam realizadas análises clínicas, hemograma, teste de função renal, hepática, além da avaliação das subpopulações celulares (TCD4, TCD8, NK, linfócitos B, células dendríticas mielóide e plasmacitóide), marcador de ativação celular (HLA-DR e CD69), grânulos citotóxicos (granzima B/perforina), citocinas (IFN-gama, TNF-alpha, IL-12, IL-10, IL-2, IL-4, IL-5 e IL-6), marcadores de proliferação (Ki-67) e ligados a apoptose (BcL-2). A vacina se mostrou segura, sem causar efeitos adversos relacionados ao local da inoculação, não induziu disfunção hepática ou renal nem alterações hematológicas. A vacinação não induziu conversão ao teste tuberculínico. Observamos um aumento de células T CD4+ de memória central, o que caracteriza ativação celular...

Tuberculosis is a chronic infectious disease caused by Mycobacteriumtuberculosis and was declared a public health emergency by World HealthOrganization. Tuberculosis remains a worldwide health problem, partly becauseinfected individuals often refuse the long- treatment. Widespread vaccinationwith BCG reduced the occurrence of severe forms of tuberculosis in children;however, pulmonary tuberculosis in adult is the main cause of deathworldwide. To validate new vaccines for clinical use in human, preclinical testsin animal model to reproduce human disease is necessary. Our mean goal wasto evaluated, the safety and immunogenicity of a new vaccine pVAX-hsp65,administrated by electroporation in cynomolgus monkeys in three doses withone month apart. Clinical analyzes were performed: Red and white blood cellscount, renal and liver functional test, evaluation of lymphocyte subsets (CD4,CD8, NK, B lymphocytes, and myeloid and plasmacytoide dendritic cells),markers for cell activation (HLA-DR and CD69), activation of cytotoxic granules(granzyme B / perforin), cytokines (IFN-gamma, TNF-alpha, IL-12, IL-10, IL-2, Il-4, IL-5and IL-6), proliferation (Ki-67) and anti-apoptosis (BCL-2) markers. The vaccineproved to be safe, with no adverse effects related to the inoculation site and didnot induce liver or kidney dysfunction or hematological changes. Thevaccination did not convert the tuberculin skin test. We observed anenhancement of central memory TCD4 lymphocytes which indicates cellactivation...

Mycobacterium arupense pulmonary infection: Antibiotic resistance and restriction fragment length polymorphism analysis.

Mycobacterium arupense is a novel mycobacterium species. It was first identified from clinical specimens in 2006 and since then there have been only two reports of its recovery from clinical samples. In the present case M. arupense was isolated from the sputum of a 62-year-old man with a malignant mass in his left kidney, who presented with a one-month history of recurrent fever, dyspnea and haemoptysis. M. arupense was identified with sequencing of hsp65 and 16S rRNA genes. In the present study, its biochemical profile along with its resistance status and hsp65 RFLP analysis is presented.

Diferenciação de micobactérias por PCR multiplex / Differentiation of micobacteria by multiplex PCR

O trabalho visou à otimização de um método baseado na reação em cadeia da polimerase multiplex - para diferenciação de micobactérias de interesse para a saúde pública. A PCR Multiplex baseou-se na amplificação simultânea do genehsp65, presente em todo gênero Mycobacterium, do gene dnaJ, presente apenas em Mycobacterium tuberculosis e Mycobacterium avium e da sequência de inserção IS6110 presente no complexo Mycobacterium tuberculosis, gerando amplicons de 165pb, 365pb e 541pb, respectivamente. O limite de detecção foi de 1fg para o alvo hsp65, 100pg para o dnaJ e 0,1fg para o IS6110. A PCR multiplex detectou até 100pg de DNA de Mycobacterium tuberculosis. O sistema demonstrou ser específico e sensível na detecção de Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium avium e Mycobacterium smegmatis. Os resultados obtidos utilizando cepas de referência demonstraram que a PCR multiplex pode ser uma ferramenta rápida, sensível e específica na diferenciação de micobactérias.

This study aimed to optimize a method based on the polymerase chain reaction - multiplex PCR - for differentiation of mycobacteria species of interest for public health. The multiplex PCR was based on simultaneous amplification of the hsp65 gene, which is present in all species of the Mycobacterium genus, the dnaJ gene, which is present only in Mycobacterium tuberculosis and Mycobacterium avium and the IS6110 insertion sequence, which is present in the Mycobacterium tuberculosis complex, generating amplicons of 165 bp, 365 bp and 541 bp, respectively. The detection limit was 1 fg for the hsp65 target, 100 pg for dnaJ and 0.1 fg for IS6110. The multiplex PCR detected down to 100 pg of DNA of Mycobacterium tuberculosis. The system was shown to be specific and sensitive for detection of Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium avium and Mycobacterium smegmatis. The results obtained using reference strains of mycobacteria showed that multiplex PCR may be a fast, sensitive and specific tool for differentiation of mycobacteria.

Mycobacterium thermoresistibile: Case report of a rarely isolated mycobacterium from Europe and review of literature.

Mycobacterium thermoresistibile is a non-tuberculous mycobacterium strongly associated with human infections. Since 1966, there have only been six reports of its isolation from clinical samples. We report on the first case from Europe and review all the previous cases. Identification was achieved with sequencing of the 16S rRNA and hsp65 genes. This study presents its phenotypic and biochemical profile, susceptibilities to selected antibiotics and hsp65 polymerase chain reaction-restriction fragment length polymorphism profile with BsteII and Hae III .

Th1 polarized response induced by intramuscular DNA-HSP65 immunization is preserved in experimental atherosclerosis

We previously reported that a DNA vaccine constructed with the heat shock protein (HSP65) gene from Mycobacterium leprae (DNA-HSP65) was protective and also therapeutic in experimental tuberculosis. By the intramuscular route, this vaccine elicited a predominant Th1 response that was consistent with its protective efficacy against tuberculosis. It has been suggested that the immune response to Hsp60/65 may be the link between exposure to microorganisms and increased cardiovascular risk. Additionally, the high cholesterol levels found in atherosclerosis could modulate host immunity. In this context, we evaluated if an atherogenic diet could modulate the immune response induced by the DNA-HSP65 vaccine. C57BL/6 mice (4-6 animals per group) were initially submitted to a protocol of atherosclerosis induction and then immunized by the intramuscular or intradermal route with 4 doses of 100 mug DNA-HSP65. On day 150 (15 days after the last immunization), the animals were sacrificed and antibodies and cytokines were determined. Vaccination by the intramuscular route induced high levels of anti-Hsp65 IgG2a antibodies, but not anti-Hsp65 IgG1 antibodies and a significant production of IL-6, IFN-g and IL-10, but not IL-5, indicating a Th1 profile. Immunization by the intradermal route triggered a mixed pattern (Th1/Th2) characterized by synthesis of anti-Hsp65 IgG2a and IgG1 antibodies and production of high levels of IL-5, IL-6, IL-10, and IFN-g. These results indicate that experimentally induced atherosclerosis did not affect the ability of DNA-HSP65 to induce a predominant Th1 response that is potentially protective against tuberculosis.

Effect of environmental mycobacteria (Mycobacterium avium) on immunity induced by a DNA vaccine (DNAhsp65) against tuberculosis

The efficacy of BCG vaccine (attenuated Mycobacterium bovis) against pulmonary tuberculosis varies enormously among different populations. The prevailing hypothesis attributes this variation to interactions between the vaccine and mycobacteria common in the environment. Studies have revealed that most protective antigens expressed by the antituberculous vaccine are conserved in M. avium, supporting the hypothesis that exposure to environmental mycobacteria generates a cross-reactive immune response that interferes with BCG efficacy. In this study we investigated the effect of a prior exposure to heat-killed M. avium on the immune response and the protective efficacy induced by a genetic vaccine pVAXhsp65 (hsp65 gene from M. leprae inserted in pVAX vector) against experimental tuberculosis. To evaluate the effect on the immune response, female BALB/c mice were initially injected with distinct doses (0.08x106, 4x106, and 200x106) of heat-killed M. avium by subcutaneous route. Three weeks later, the animals were immunized with 3 doses of DNAhsp65 by intramuscular route (100µg/15 days apart). Control groups received only M. avium, vaccine (pVAXhsp65), vector (pVAX) or saline solution. Cytokine production and antibody levels were determined by ELISA. To evaluate the effect on the protective efficacy, animals were initially sensitized with 200x106 heat-killed CFU of M. avium by subcutaneous route and then immunized with 3 doses of pVAXhsp65 (100µg/15 days apart) by intramuscular route. Control groups were injected with saline, pVAX (4 doses), pVAXhsp65 (4 doses), M. avium or M. avium plus pVAX (3 doses). Fifteen days after last DNA dose, the animals were infected with 1x104 viable CFU of H37Rv M. tuberculosis by intratracheal route. Thirty days after challenge, the animals were sacrificed and the bacterial burden was determined by counting the number of CFU in the lungs. Lung histological sections were also analyzed. Splenic cells from primed animals produced more IL-5 but less IFN-gamma than non-primed ones. Also, prior contact with M. avium determined higher production of IgG1 and IgG2a anti-hsp65 antibodies in comparison to control groups. However, this higher immune response did not decrease the bacterial burden in the lungs. In addition, prior sensitization with M. avium decreased the parenchyma preservation observed in the group immunized only with pVaxhsp65. These results indicate that environmental mycobacteria can interfere with immunity and protective efficacy induced by DNAhsp65.(AU)

Distribución de patrones PRA en aislamientos clínicos del complejo Mycobacterium avium procedentes de España y Suramérica

La infección por el complejo Mycobacterium avium (MAC) es la infección sistémica más frecuente en la fase terminal del SIDA. Las sondas de ADN disponibles en el mercado para la identificación de micobacterias son muy precisas pero extremadamente costosas. Por eso, la mayoría de los laboratorios clínicos de Latinoamérica aún tipifican micobacterias mediante pruebas fenotípicas que son lentas, laboriosas y poco precisas. En este trabajo se aplicó el análisis del polimorfismo de los fragmentos de restricción del gen hsp65 (PRA) a la identificación de MAC en 163 aislamientos clínicos procedentes de España y Suramérica. El genotipo PRA predominante en cada país fue: M. avium tipo I en Argentina (23/42, 55%) y Brasil (48/72, 67%), M. avium tipo II en España (18/26, 69%) y M. avium tipo III en Colombia (10/23, 43%). Este último genotipo, que aún no fue descrito fuera del continente americano, resultó muy infrecuente en los otros tres países del estudio. Se discuten ventajas e inconvenientes de la aplicación del PRA al diagnóstico micobacteriológico.

Distribution of PRA patterns of clinical isolates of the Mycobacterium avium complex from Spain and South America Mycobacterium avium complex (MAC) infections are the most frequent systemic infections associated with advanced AIDS. DNA probes for accurate identification of mycobacteria are available but are very expensive in many Latin American settings. Consequently, most Latin American diagnostic laboratories employ inaccurate and outdated tests for mycobacteria identification. Therefore, PCR restriction analysis (PRA) of the hsp65 gene was evaluated for the identification of 163 MAC human isolates originated from Spain and South America. The predominant PRA type in each country was: M. avium type I in Argentina (23/42, 55%) and Brazil (48/72, 67%), M. avium type II in Spain (18/26, 69%) and M. avium type III in Colombia (10/ 23, 43%). The Colombia frequency is noteworthy, since the PRA type III was quite infrequent in the other three countries. Furthermore, its presence has not been reported outside the Americas. The advantages and disadvantages of PRA in diagnostic mycobacteriology are discussed.

Construction of eukaryotic expression vector and DNA immune experiment pcHSP65 of mycobacterium tuberculosis / 中国免疫学杂志

Objective:To construct nucleotide vaccine based on HSP65 gene of mycobacterium tuberculosis.Methods:The gene encoding heat shock protein 65 kilodalton was amplified from genome of mycobacterium tuberculosis H37Rv strain by polymerase chain reaction(PCR) and correctly inserted into corresponding sites of eukaryotic expression vector pcDNA3.1(-) after restriction endonuclease digestion.The experimental mice was vaccined by this recombinant plasmid DNA.Results:The gene fragment inserted into the vector pcDNA3.1(-) was the HSP65 gene of mycobacterium tuberculosis H37Rv strain,which was confirmed by partial nucleotide sequencing.There was specific antibody produce in experimental mice vaccined by the recombinant plasmid DNA and this could protect mice against infection of mycobacterium tuberculosis.Conclusion:The successful construction of recombinant eukaryotic expression vector based on HSP65 gene of mycobacterium tuberculosis,such recombinant plasmid DNA induced specific antibody production in experimental mice,lays the foundation for further researching in prevention and treatment of tuberculosis.