Interferon-gamma release assay performance in northeastern Brazil: influence of the IFNG+874 A>T polymorphism

ABSTRACT Introduction Latent tuberculosis infection diagnosis based on the release of interferon-gamma in cultures of peripheral blood cells stimulated with Mycobacterium tuberculosis antigens has replaced the tuberculin skin test in many countries with low tuberculosis prevalence. The IFN-γ production can be influenced by genetic polymorphisms, of which the IFNG + 874 (rs62559044) locus is the most studied. We investigated the possible influence of the IFNG + 874 A/T polymorphism on interferon-gamma test performance. Methods Patients diagnosed with pulmonary tuberculosis (75), volunteers with positive tuberculin skin test (70) and healthy volunteers with negative tuberculin skin test and no history of contact with tuberculosis (57) were evaluated regarding the IFNG + 874 genotype and the IFN-γ levels in whole blood cultures performed using an interferon-gamma commercial kit (QuantiFERON-TB® Gold In-Tube). Results IFN-γ production was not influenced by the IFNG + 874 genotype, regardless of antigen or mitogen-based stimulation, which suggests that other genes may influence IFN-γ production in response to mycobacteria. The IFNG + 874 polymorphism was found to exert no influence over QFT-IT test sensitivity in our study. Conclusions The IFNG + 874 polymorphism was not shown to influence QuantiFERON-TB® Gold In-Tube test performance in an admixed population from northeastern Brazil.

Single nucleotide polymorphisms of cytokine-related genes and association with clinical outcome in a Chagas disease case-control study from Brazil

BACKGROUND The severity of chronic chagasic cardiomyopathy (CCC), the most frequent clinical outcome of Chagas disease (CD), has been associated with cytokine-enriched heart tissue inflammation, and high serum levels of transforming growth factor (TGFβ), interferon-gamma (IFNγ), and tumour necrosis factor (TNF). Conversely, increased interleukin (IL)-10 serum concentrations have been associated with asymptomatic CD. Cytokines and cytokine-related gene polymorphisms may control cytokine expression and have been proposed to contribute to CCC outcomes. OBJECTIVES We evaluated the association of 13 cytokine-related genes (TGFB: rs8179181, rs8105161, rs1800469; IL10: rs1800890, rs1800871, rs1800896; IFNG: rs2430561; TNF: rs1800629; BAT1: rs3853601; LTA: rs909253, rs2239704; TNFR1: rs767455; TNFR2: rs1061624) with risk and progression of CCC. FINDINGS Four hundred and six seropositive patients from CD endemic areas in the state of Pernambuco, north-eastern Brazil, were classified as non-cardiopathic (A, 110) or cardiopathic (mild, B1, 163; severe, C, 133). We found no evidence of TGFB, IL10, TNF, or TNFR1/2 gene polymorphisms associated with CCC risk or progression. Only BAT1 rs3853601 −22G carriers (B1 vs. C: OR = 0.5; p-value = 0.03) and IFNG rs2430561 +874AT (A vs. C: OR = 0.7; p-value = 0.03; A vs. B1+C: OR = 0.8; p-value = 0.02) showed a significant association with protection from cardiopathy in a logistic regression analysis with adjustment for gender and ethnicity; however, the association disappeared after performing adjustment for multiple testing. A systematic review of TNF rs1800629 −308G>A publications included five studies for meta-analysis (534 CCC and 472 asymptomatic patients) and showed no consensus in pooled odds ratio (OR) estimates for A allele or A carriers (OR = 1.4 and 1.5; p-values = 0.14 and 0.15, respectively). In CD patients, TNF serum levels were increased, but not affected by the TNF rs1800629 −308A allele. MAIN CONCLUSIONS Our data suggest no significant contribution of the analysed gene variants of cytokine-related molecules to development/severity of Chagas' heart disease, reinforcing the idea that parasite/host interplay is critical to CD outcomes.

Variantes en los genes TNFA , IL6 e IFNG asociadas con la gravedad del dengue en una muestra de población colombiana / Variants in the TNFA , IL6 and IFNG genes associated with dengue severity in a sample of Colombian population

Resumen Introducción. La composición genética del huésped determina, entre otros aspectos, el perfil clínico del dengue, lo cual se debería al efecto de variantes en los genes que codifican citocinas proinflamatorias. Objetivo. Evaluar la asociación entre las variantes de tres polimorfismos en los genes candidatos TNFA, IL6 e IFNG con la gravedad del dengue en una población colombiana. Materiales y métodos. Se evaluaron los polimorfismos rs1800750, rs2069843 y rs2069705 de los genes TNFA, IL6 e IFNG, respectivamente, en 226 pacientes con dengue. Los genotipos se tipificaron usando la reacción en cadena de la polimerasa (PCR) y los polimorfismos de la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism, RFLP). Para determinar el riesgo de diferentes fenotipos del dengue, se compararon las frecuencias alélicas con la prueba de ji al cuadrado, y los genotipos y los haplotipos, con regresión logística. Por último, los análisis se ajustaron utilizando datos de autoidentificación o del componente genético ancestral. Resultados. El alelo A del rs2069843, ajustado por autoidentificación, se asoció con casos de dengue hemorrágico en afrocolombianos. En la muestra completa, dicho polimorfismo, ajustado por componente genético ancestral, fue reproducible. Además, hubo asociaciones significativas entre las combinaciones alélicas GGT y GAC de los rs1800750, rs2069843 y rs2069705 en pacientes con dengue hemorrágico, con ajuste por componente genético ancestral y sin él. Además, la combinación alélica AGC produjo 58,03 pg/ml más de interleucina 6 que la GGC, independientemente de los componentes genéticos europeo, amerindio y africano. Conclusión. Las variantes de los polimorfismos GGT y GAC de los rs1800750, rs2069843 y rs2069705 en los genes TNFA, IL6 e IFNG, respectivamente, se correlacionaron con la gravedad del dengue en esta muestra de población colombiana.

Abstract Introduction: The genetic makeup of the host contributes to the clinical profile of dengue. This could be due to the effect of variants in the genes encoding pro-inflammatory cytokines. Objective: To evaluate the association between the variants of three polymorphisms in TNFA, IL6 and IFNG candidate genes with dengue severity in a sample of Colombian population. Materials and methods: We evaluated the rs1800750, rs2069843, and rs2069705 polymorphisms in TNFA, IL6 and IFNG candidate genes, respectively, in 226 patients with dengue infection. The genotypes were typed using both polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). To determine the risk of different dengue phenotypes, we compared allele frequencies with chisquare and genotypes and haplotypes using logistic regression. Finally, these analyzes were adjusted with data from self-identification or the ancestral genetic component. Results: The A allele in the rs2069843 polymorphism, adjusted by self-identification, was associated with dengue hemorrhagic fever cases in Afro-Colombians. In the entire sample, this polymorphism, adjusted by the ancestral genetic component, was reproducible. In addition, there were significant associations between GGT and GAC allelic combinations of rs1800750, rs2069843, and rs2069705 in dengue hemorrhagic fever patients, with and without adjustment by ancestral genetic component. Additionally, the AGC allelic combination produced 58.03 pg/ml of interleukin-6 more than the GGC combination, regardless of European, Amerindian and African genetic components. Conclusions: The variants of GGT and GAC polymorphisms of rs1800750, rs2069843, and rs2069705 in the TNFA, IL6 and IFNG genes, respectively, were correlated with the susceptibility to dengue severity in a sample of Colombian population.

Concordance between IFNγ gene +874 A/T polymorphism and interferon-γ expression in a TB-endemic indigenous setting

Abstract INTRODUCTION: Interferon-γ (IFN-γ) plays a crucial role in resistance to mycobacterial diseases; accordingly, variants of the gene encoding this cytokine may be associated with elevated risk of contracting pulmonary tuberculosis (TB). METHODS: Blood samples were collected from 135 Warao indigenous individuals with newly diagnosed sputum culture-positive TB. Of these, 24 were diagnosed with active tuberculosis (ATB). The study comprised 111 participants, who were grouped as follows: 1) 14 tuberculin skin test (TST)-positive Warao indigenous individuals and 4 that were QuantiFERON-TB?Gold In-Tube (QFT-IT) test-positive, collectively comprising the latent TB infection group (LTBI), n = 18), and 2) healthy controls who were QFT-IT- and TST-negative, comprising the control group (CTRL, n = 93). Detection of the IFN γ gene (IFNG) +874A/T polymorphism was performed via PCR and quantification of IFNG expression via qPCR. RESULTS: Relative to indigenous and white Americans, ATB and CTRL groups had a higher frequency of the IFNG SNP (+874A): 23 (95.8%) and 108 (97.3%), respectively. Indigenous Warao individuals homozygous for the IFNG (+874) A allele exhibited 3.59-fold increased risk of developing TB (95% confidence interval, 2.60-4.96, p =0.0001). A decreased frequency of the AT genotype was observed in individuals with pulmonary TB (4.16%) and controls (0.90%). The frequency of the TT genotype was decreased among controls (1.80%); none of the patients with TB were found to have this genotype. The differences in IFNG expression between the groups, under unstimulated and stimulated conditions, were not statistically significant. CONCLUSIONS: Preliminary results demonstrate concordance between IFNG +874 A/A genotype and low expression of IFNG.

Análisis molecular del cáncer de colon esporádico / Molecular analysis of sporadic colon cancer

Background: In Chile, colorectal cancer (CRC) is often diagnosed in late stages. Thus, surgical treatment must be complemented with chemotherapy. KRAS mutations and microsatellite instability have been detected in these tumors. However, the response to treatment in patients without KRAS mutations varies and requires a better understanding. Aim: To determine the frequency and distribution of somatic point mutations in KRAS, BRAF and PIK3CA genes and microsatellite instability status (MSI) in patients with colon cancer (CC). Material and Methods: A prospective observational study of patients undergoing surgery for colon cancer. Tumor-derived DNA was analyzed by polymerase chain reaction (PCR) for the most frequent mutations of KRAS, BRAF and PIK3CA. PCR was also used to analyze MSI. Results: Fifty-eight patients with sporadic CC were analyzed, 16 showed KRAS mutations (G12R, G12D, G12V, G13D) and out of the 42 patients that did not show any mutation, 10 had mutations in BRAF (V600E) and PIK3CA (E542K, E545D, E545K, Q546E, H1047R). BRAF mutations alone or in combination with PIK3CA mutations were observed in 27% of high MSI tumors and in 2% of tumors without instability (p < 0.049). A higher percentage of high MSI tumors were located in the right colon (p < 0.001), and showed BRAF mutation (p < 0.020). Conclusions: The highest percentage of high MSI and BRAF mutations was observed in the right colon. Therefore, this study suggests the presence of different molecular features between right and left colon tumors that should be considered when defining the therapeutic management.

Increased circulating macrophage migration inhibitory factor levels are associated with coronary artery disease

BACKGROUND: To evaluate the macrophage migration inhibitory factor and E-selectin levels in patients with acute coronary syndrome. MATERIALS/METHODS: We examined the plasma migration inhibitory factor and E-selectin levels in 87 patients who presented with chest pain at our hospital. The patients were classified into two groups according to their cardiac status. Sixty-five patients had acute myocardial infarction, and 22 patients had non-cardiac chest pain (non-coronary disease). We designated the latter group of patients as the control group. The patients who presented with acute myocardial infarction were further divided into two subgroups: ST-elevated myocardial infarction (n = 30) and non-ST elevated myocardial infarction (n = 35). RESULTS: We found higher plasma migration inhibitory factor levels in both acute myocardial infarction subgroups than in the control group. However, the E-selectin levels were similar between the acute myocardial infarction and control patients. In addition, we did not find a significant difference in the plasma migration inhibitory factor levels between the ST elevated myocardial infarction and NST-elevated myocardial infarction subgroups. DISCUSSION: The circulating concentrations of migration inhibitory factor were significantly increased in acute myocardial infarction patients, whereas the soluble E-selectin levels were similar between acute myocardial infarction patients and control subjects. Our results suggest that migration inhibitory factor may play a role in the atherosclerotic process. .

The enhanced expression of IL-17-secreting T cells during the early progression of atherosclerosis in ApoE-deficient mice fed on a western-type diet

Atherosclerosis is a chronic progressive inflammatory disorder and the leading cause of cardiovascular mortality. Here we assessed the dynamic changes of T-cell-derived cytokines, such as inteferon (IFN)-gamma, interleukin (IL)-17 and IL-4, during the progression of atherosclerosis in apolipoprotein E-null (ApoE(-/-)) mice, to understand the role of immune responses in different stages of atherosclerosis. Male ApoE(-/-) mice were fed a high-fat, western-type diet (WD: 21% lipid, 1.5% cholesterol) after 5 weeks of age and were compared with C57BL/6 wild-type control mice fed a standard chow diet. Atherosclerotic lesions appeared in the aortic sinus of ApoE(-/-) mice 4 weeks after WD and the lesions progressed and occupied >50% of the total sinus area 16 weeks after WD. Aortic IL-17 mRNA and protein expression started to increase in ApoE(-/-) mice after 4 weeks on the WD and peaked at around 8-12 weeks on the WD. In terms of systemic expression of T-cell-derived cytokines, IL-17 production from splenocytes after anti-CD3/CD28 stimuli increased from 4 weeks on the WD, peaked at 12 weeks and returned to control levels at 16 weeks. The production of IFN-gamma and IL-4 (Th1 and Th2 cytokines, respectively) from splenocytes was delayed compared with IL-17. Taken together, the present data indicate that Th17 cell response may be involved at an early stage in the development of atherosclerosis.

The enhanced expression of IL-17-secreting T cells during the early progression of atherosclerosis in ApoE-deficient mice fed on a western-type diet

Atherosclerosis is a chronic progressive inflammatory disorder and the leading cause of cardiovascular mortality. Here we assessed the dynamic changes of T-cell-derived cytokines, such as inteferon (IFN)-gamma, interleukin (IL)-17 and IL-4, during the progression of atherosclerosis in apolipoprotein E-null (ApoE(-/-)) mice, to understand the role of immune responses in different stages of atherosclerosis. Male ApoE(-/-) mice were fed a high-fat, western-type diet (WD: 21% lipid, 1.5% cholesterol) after 5 weeks of age and were compared with C57BL/6 wild-type control mice fed a standard chow diet. Atherosclerotic lesions appeared in the aortic sinus of ApoE(-/-) mice 4 weeks after WD and the lesions progressed and occupied >50% of the total sinus area 16 weeks after WD. Aortic IL-17 mRNA and protein expression started to increase in ApoE(-/-) mice after 4 weeks on the WD and peaked at around 8-12 weeks on the WD. In terms of systemic expression of T-cell-derived cytokines, IL-17 production from splenocytes after anti-CD3/CD28 stimuli increased from 4 weeks on the WD, peaked at 12 weeks and returned to control levels at 16 weeks. The production of IFN-gamma and IL-4 (Th1 and Th2 cytokines, respectively) from splenocytes was delayed compared with IL-17. Taken together, the present data indicate that Th17 cell response may be involved at an early stage in the development of atherosclerosis.

Single nucleotide polymorphisms in the interferon gamma gene are associated with distinct types of retinochoroidal scar lesions presumably caused by Toxoplasma gondii infection

The association of single nucleotide polymorphisms (SNPs) in the interferon (IFN)-γ gene ( IFNG ) with different types of retinal scar lesions presumably caused by toxoplasmosis were investigated in a cross-sectional population-based genetic study. Ten SNPs were investigated and after Bonferroni correction, only the associations between SNPs rs2069718 and rs3181035 with retinal/retinochoroidal scar lesions type A (most severe scar lesions) and C (least severe scar lesions), respectively, remained significant. The associations of two different IFNG SNPs with two different types of retinal lesions attributable to toxoplasmosis support the hypothesis that different inflammatory mechanisms underlie the development of these lesions. The in vitro analysis of IFN-γ secretion by peripheral blood mononuclear cells stimulated with Toxoplasma gondii antigens was also investigated. The association between SNP rs2069718 and type A scar lesions revealed that differential IFN-γ levels are correlated with distinct genotypes. However, no correlation was observed with IFN-γ secretion levels and the SNP rs3181035 , which was significantly associated with type C scar lesions. Our findings strongly suggest that immunogenetic studies of individuals with congenital or postnatally acquired infection are needed to better understand the role of IFN-γ and its polymorphisms in the pathogenesis of ocular toxoplasmosis.

Evaluation of IFN-gamma polymorphism in visceral leishmaniasis

Leishmaniasis is a tropical disease that is endemic in some areas of Iran, including East Azerbaijan. IFN- gamma is one of the cytokines that triggers cell-mediated immunity, thus initiating elimination of the infection. This case-control study was performed to investigate the association between the polymorphism of the IFN- gamma gene at the +874A/T locus and visceral leishmaniasis [VL]. In this study conducted during 2012-2013, 267 participants were selected from individuals living in an endemic area of VL. Subjects were divided into three groups; 86 patients with VL, 82 seropositive individuals without any history of leishmaniasis, and 99 seronegative healthy controls. Genotyping of the IFN- gamma +874A/T polymorphism was carried out using an Amplification Refractory Mutation System-PCR [ARMS-PCR]. The frequency of the +874A allele in the patient group [75.5%] was higher than in the seropositive individuals [54%]. The highest frequency of the +874T/T genotype was observed in seropositive individuals, while the patient group had the lowest frequency [34.1% vs. 24.5%]. However, these differences were not significant. There was no significant association between IFN- gamma +874A/T polymorphism and VL

Inflammatory and immunogenetic markers in correlation with pulmonary tuberculosis / Marcadores inflamatorios e imunogeneticos e sua relacao com tuberculose pulmonar

OBJECTIVE: To describe serum levels of the cytokines IL-10, TNF-α, and IFN-γ, as well as polymorphisms in the genes involved in their transcription, and their association with markers of the acute inflammatory response in patients with pulmonary tuberculosis. METHODS: This was a descriptive, longitudinal study involving 81 patients with pulmonary tuberculosis treated at two referral hospitals. We collected data on sociodemographic variables and evaluated bacteriological conversion at the eighth week of antituberculosis treatment, gene polymorphisms related to the cytokines studied, and serum levels of those cytokines, as well as those of C-reactive protein (CRP). We also determined the ESR and CD4+ counts. RESULTS: The median age of the patients was 43 years; 67 patients (82.7%) were male; and 8 patients (9.9%) were infected with HIV. The ESR was highest in the patients with high IFN-γ levels and low IL-10 levels. IFN-γ and TNF-α gene polymorphisms at positions +874 and −238, respectively, showed no correlations with the corresponding cytokine serum levels. Low IL-10 levels were associated with IL-10 gene polymorphisms at positions −592 and −819 (but not −1082). There was a negative association between bacteriological conversion at the eighth week of treatment and CRP levels. CONCLUSIONS: Our results suggest that genetic markers and markers of acute inflammatory response are useful in predicting the response to antituberculosis treatment. .

OBJETIVO: Descrever os níveis séricos das citocinas IL-10, TNF-α e IFN-γ, assim como polimorfismos presentes em genes envolvidos na sua transcrição, e sua associação com marcadores de resposta inflamatória aguda em pacientes com tuberculose. MÉTODOS: Estudo descritivo e longitudinal realizado em 81 pacientes com tuberculose pulmonar atendidos em dois hospitais de referência. Foram coletadas informações sociodemográficas, conversão bacteriológica na oitava semana de tratamento antituberculose, polimorfismos relacionados às citocinas estudadas, níveis séricos dessas citocinas, assim como de proteína C reativa (PCR). Também foram avaliados VHS e contagem de CD4+. RESULTADOS: A mediana de idade dos pacientes era de 43 anos, sendo 67 (82,7%) do sexo masculino e 8 (9,9%) infectados por HIV. Os pacientes com níveis elevados de IFN-γ e baixos níveis de IL-10 apresentaram valores mais elevados de VHS. Não houve associação dos polimorfismos do gene IFN-γ na posição +874 e do gene TNF-α na posição −238 com os níveis das citocinas correspondentes. Houve uma associação entre polimorfismos do gene IL-10 nas posições −592 e −819 (mas não −1082) e baixos níveis de IL-10. Houve uma associação negativa entre a taxa de conversão bacteriológica na oitava semana de tratamento e níveis de PCR. CONCLUSÕES: Nossos resultados sugerem que marcadores genéticos e de resposta inflamatória aguda podem ser úteis na predição da resposta ao tratamento antituberculose. .

Variants in the IFN ? transcription factor genes TBET, STAT1, STAT4, and HLX and the risk of pulmonary tuberculosis in a Colombian population: a case-control study / Variantes en los factores de transcripción para IFN ?, TBET, STAT1 , STAT4 y HLX , y el riesgo de desarrollar tuberculosis pulmonar en un estudio de casos y controles de una población colombiana

Introduction: Interferon gamma (IFN ? ) is the most potent cytokine involved in the control of Mycobacterium tuberculosis ( Mtb ), the etiological agent of human tuberculosis (TB). Patients with active TB present reduced levels of IFN ? , which may explain the lack of effective immunity against Mtb in these patients. The diminished expression of or functional alterations in trans-acting factors that regulate IFN ? gene expression may explain the reduced levels of IFN ? in TB patients. Objective: To investigate the relationships of genetic variants in the transcription factors TBET, STAT1, STAT4, and HLX to susceptibility/resistance to pulmonary TB. Materials and methods: Eight candidate single-nucleotide polymorphisms (SNPs) were selected, and genotyped in 466 unrelated pulmonary TB patients and 300 healthy controls from Colombia, and the allelic and genetic associations with TB were analyzed. Results: The results indicate that no SNP in the transcription factors studied is associated with TB. However, polymorphism rs11650354 in the TBET gene may be associated with a decreased risk of TB; the TT genotype was significantly associated with TB protection in a recessive genetic model (OR=0.089, 95% CI: 0.01-0.73, p=0.0069), although this association was not maintained after multiple test correction (EMP2= 0.61). Conclusion: In this study, the rs11650354 variant of TBET was suggested to promote resistance to TB in a Colombian population. A future replication case-control study using additional samples will be necessary to confirm this suggestive association.

Introducción. El interferón gama (IFN ? ) es la citocina más potente para controlar la infección por Mycobacterium tuberculosis , el agente etiológico de la tuberculosis humana. Los pacientes con tuberculosis activa presentan reducción de los niveles de IFN ? , lo cual parece explicar la inmunidad poco efectiva contra el bacilo. La disminución de su expresión o alteraciones funcionales de los factores transactivadores del promotor del gen de IFN ? , podrían explicar la reducción de los niveles de IFN ? en los pacientes con tuberculosis. Objetivo. Determinar la asociación de variantes genéticas en los factores de transcripción TBET STAT1, STAT4 y HLX con sensibilidad o resistencia a tuberculosis pulmonar. Materiales y métodos. Se seleccionaron ocho polimorfismos de un solo nucleótido ( Single-Nucleotide Polymorphism , SNP) y se estableció su genotipo, en 466 pacientes con tuberculosis pulmonar y 300 controles sanos en Colombia; además, se hizo un análisis de asociación alélica y genética. Resultados. Los resultados indican que los SNP de los factores de transcripción estudiados no están asociados con tuberculosis; sin embargo, el polimorfismo rs11650354 en TBET puede estar implicado en la disminución de riesgo de tuberculosis. El genotipo TT de TBET se asoció significativamente con protección contra tuberculosis usando un modelo genético recesivo (OR=0,089; CI 95% : 0,01-0,73; p=0,0069); sin embargo, la corrección mediante pruebas múltiples de ajuste abolió esta asociación ( Empirical P Value, EMP2=0,61). Conclusión. En este estudio se sugiere un efecto de la variante rs11650354 de TBET sobre la resistencia a la tuberculosis en la población colombiana. Es necesario desarrollar un estudio de replicación usando muestras adicionales para confirmar esta asociación sugestiva.

Maximizing production of human interferon- gamma in HCDC of recombinant E. coli

Tuning recombinant protein expression is an approach which can be successfully employed for increasing the yield of recombinant protein production in high cell density cultures. On the other hand, most of the previous results reported the optimization induction conditions during batch and continuous culture of recombinant E. coli, and consequently fed-batch culture have received less attention. Hence, in this research induction conditions for the over-production of recombinant interferon- gamma including the amount of inducer, induction time and post-induction duration during chemical induction were optimized. E. coli BL21 [DE3] [pET3a-hifn gamma] was used to over-express human interferon-gamma [hIFN- gamma] in an exponential fed-batch procedure with a maximum attainable specific growth rate of 0.55 h[-1] at the beginning of feeding and 0.4 h[-1] in induction time. The factors were considered as the amount of inducer [IPTG] in the range of 0.565- 22 mg g[-1] L[-1] at seven levels, cell density at induction time as 53, 65 and 75 g [dry cell weight] L[-1], induction duration at different intervals of 3, 4, and 5 h after induction time. The final concentration of biomass and interferon gamma reached to 127 g L[-1] [DCW] and 51 g [hIFN-gamma] L[-1] after 17 h, and also the final specific yield and overall productivity were obtained 0.4 g [hIFN- gamma] g[-1] DCW and 3 g [hIFN- gamma] L[-1] h[-1], respectively, which are the highest amounts of reported specific yield and productivity for recombinant proteins production

Kinetics of IFN-Gamma and TNF-Alpha Gene Expression and Their Relationship with Disease Progression after Infection with Mycobacterium Tuberculosis in Guinea Pigs

PURPOSE: Guinea pig is one of the most suitable animal models for Mycobacterium tuberculosis (M. tb) infection since it shows similarities to pulmonary infection in humans. Although guinea pig shows hematogenous spread of M. tb infection into the whole body, immunological studies have mainly focused on granulomatous tissues in lungs and spleens. In order to investigate the time-course of disease pathogenesis and immunological profiles in each infected organ, we performed the following approaches with guinea pigs experimentally infected with M. tb over a 22-week post-infection period. MATERIALS AND METHODS: We examined body weight changes, M. tb growth curve, cytokine gene expression (IFN-gamma and TNF-alpha), and histopathology in liver, spleen, lungs and lymph nodes of infected guinea pigs. RESULTS: The body weights of infected guinea pigs did not increase as much as uninfected ones and the number of M. tb bacilli in their organs increased except bronchotracheal lymph node during the experimental period. The gene expression of IFN-gamma and TNF-alpha was induced between 3 and 6 weeks of infection; however, kinetic profiles of cytokine gene expression showed heterogeneity among organs over the study period. Histophathologically granulomatous lesions were developed in all four organs of infected guinea pigs. CONCLUSION: Although IFN-gamma and TNF-alpha gene expression profiles showed heterogeneity, the granuloma formation was clearly observed in every organ regardless of whether the number of bacilli increased or decreased. However, this protective immunity was accompanied with severe tissue damage in all four organs, which may lead to the death of guinea pigs.

Genetic polymorphism for IFNγ +874T/A in patients with acute toxoplasmosis / Polimorfismo genético para IFNγ +874T/A em pacientes com toxoplasmose aguda

INTRODUCTION: A single nucleotide polymorphism (SNP) in the gene encoding gamma interferon influences its production and is associated with severity of infectious diseases. This study aimed to evaluate the association of IFNγ+874T/A SNP with duration of disease, morbidity, and development of retinochoroiditis in acute toxoplasmosis. METHODS: A case-control study was conducted among 30 patients and 90 controls. RESULTS: Although statistical associations were not confirmed, A-allele was more common among retinochoroiditis cases and prolonged illness, while T-allele was more frequent in severe disease. CONCLUSIONS: Despite few cases, the results could indicate a relation between IFNγ+874T/A single nucleotide polymorphism and clinical manifestations of toxoplasmosis.

INTRODUÇÃO: Um polimorfismo de nucleotideo único (SNP) no gene codificante para interferon gama influencia a sua produção e pode estar associado à gravidade de diversas doenças infecciosas. O objetivo deste estudo foi avaliar a associação entre SNP para IFNγ+874T/A com a duração da doença, a morbidade e o desenvolvimento de retinocoroidite na toxoplasmose aguda. MÉTODOS: Estudo de caso-controle incluindo 30 pacientes e 90 controles. RESULTADOS: Apesar da ausência de associação estatística, o alelo A foi mais comum entre os casos com retinocoroidite e doença prolongada e o alelo T nas formas mais severas. CONCLUSÕES: Os dados encontrados sugerem uma relação entre o polimorfismo de base única em IFNγ+874T/A com a morbidade e com o desenvolvimento de retinocoroidite por toxoplasmose.

Non-association of IL-12 +1188 and IFN-gamma +874 polymorphisms with cytokines serum level in occult HBV infected patients

Occult hepatitis B infection [OBI] is identified as a form of hepatitis in which despite the absence of detectable HBsAg, HBV-DNA is observed in peripheral blood of patients. The main aim of this study has been to investigate the association between polymorphisms in +874 of IFN-gamma and +1188 of IL-12 with their serum level in patients suffering from OBI. In this experimental study, plasma samples of 3700 blood donors were tested for the presence of hepatitis B surface antigen [HBsAg] and anti-HBc by ELISA. The HBsAg[-]/anti-HBc[+] samples were selected and screened for HBV-DNA by PCR. HBV-DNA positive samples were assigned as OBI cases and ARMS-PCR techniques were performed to examine the two known polymorphisms within IL-12 and IFN-gamma. In addition, the serum levels of IL-12 and IFN-gamma were also determined by ELISA. Results of this study demonstrated that, 352 [9.5%] out of 3700 blood samples were HBsAg[-]/anti-HBc[+]and HBV-DNA was detected in 57/352 [16.1%] of HBsAg[-]/anti-HBc[+] samples. Our results showed that groups showed significant difference in CC allele of +1188 region of IL-12 and no difference was observed in the other evaluated genes. Our results also showed that the alleles of +1188 region of IL-12 and alleles of +874 of IFN-gamma were also not associated with serum level of cytokines. According to the results of this study, it may be concluded that the polymorphisms in +1188 region of IL-12 and +874 region of IFN-gamma would not affect the expression of both cytokines at serum level in OBI patients

Leishmania spp. parasite isolation through inoculation of patient biopsy macerates in interferon gamma knockout mice / Leishmania spp.: isolamento de parasitos pela inoculação de macerados de biopsias de pacientes em camundongos deficientes em interferon gama

Isolation of Leishmania parasite and species identification are important for confirmation and to help define the epidemiology of the leishmaniasis. Mice are often used to isolate pathogens, but the most common mouse strains are resistant to infection with parasites from the Leishmania (Viannia) subgenus. In this study we tested the inoculation of interferon gamma knockout (IFNγ KO) mice with biopsy macerates from Leishmania-infected patients to increase the possibility of isolating parasites. Biopsies from twenty five patients with clinical signs of leishmaniasis were taken and tested for the presence of parasites. Immunohistochemical assay (IHC) and conventional histopathology detected the parasite in 88 percent and 83 percent of the patients, respectively. Leishmania sp. were isolated in biopsy macerates from 52 percent of the patients by culture in Grace's insect medium, but 13 percent of isolates were lost due to contamination. Inoculation of macerates in IFNγ KO mice provides isolation of parasites in 31.8 percent of the biopsies. Most isolates belong to L. (Viannia) subgenus, as confirmed by PCR, except one that belongs to L. (Leishmania) subgenus. Our preliminary results support the use of IFNγ KO mice to improve the possibility to isolate New World Leishmania species.

O isolamento e a identificação da espécie de parasito do gênero Leishmania são importantes para a confirmação e auxiliam na epidemiologia da leishmaniose. Os camundongos são freqüentemente utilizados para isolar patógenos, porém, as linhagens mais comuns de camundongos são resistentes à infecção por parasitos do subgênero Leishmania (Viannia). Neste estudo, avaliamos a inoculação de macerados de biópsias de pacientes infectados em camundongos deficientes do gene do interferon gama (IFNγ KO) como um método para aumentar a possibilidade de isolar Leishmania spp. Biópsias de 25 pacientes infectados com Leishmania sp. foram avaliadas para a presença de parasitos pelos métodos de imunohistoquímica (IHC) e histopatologia convencional. Os parasitos foram observados, respectivamente, em 88 por cento e 83 por cento das biópsias. Leishmania sp. foi isolada de macerados de biópsia de 52 por cento dos pacientes infectados, quando cultivados em meio Grace, porém, 13 por cento destes isolados foram perdidos devido a contaminações. Inoculação dos macerados em camundongos IFNγ KO proporcionou o isolamento de parasitos oriundos de 31,8 por cento dos pacientes. A maioria dos isolados pertence ao subgênero L. (Viannia), exceto um que pertence ao subgênero L. (Leishmania), como confirmado pela reação da polimerase em cadeia. Nossos resultados preliminares sugerem que o uso de camundongos IFNγ KO pode ser útil para aumentar a possibilidade de isolamento de leishmânias encontradas nas Américas.

IFN-gamma +874 and IL-4 -590 polymorphisms and asthma susceptibility in North West of Iran

Recent studies have documented an association between some cytokines' gene polymorphisms and chronic inflammation of the respiratory tract which leads to asthma susceptibility. This study was conducted to investigate if there were any differences in IFN-gamma +874 [A/T] and IL-4 -590 [C/T] single nucleotide variations in asthmatic patients compared to normal controls among West Azerbaijani population. IFN-gamma +874 [A/T] and IL-4 -590 [C/T] polymorphisms were amplified by ASO-PCR and RFLP-PCR from genomic DNA of 173 individuals including 64 asthmatic patients and 109 control subjects from West Azerbaijani population. The allele or genotype frequencies of IFN-gamma+874 A/T in patients were not different from those of controls [p>0.05]. The differences between allelic or genotypic frequencies of IL-4 -590 C/T in patients and controls were not statistically significant [p>0.05]. These findings showed that IL-4 -590 [C/T] and IFN-gamma+874 [A/T] polymorphisms were not associated with asthma susceptibility

Immunological and non-immunological effects of cytokines and chemokines in the pathogenesis of chronic Chagas disease cardiomyopathy

The pathogenesis of Chagas disease cardiomyopathy (CCC) is not well understood. Since studies show that myocarditis is more frequent during the advanced stages of the disease, and the prognosis of CCC is worse than that of other dilated cardiomyopathies of non-inflammatory aetiology, which suggest that the inflammatory infiltrate plays a major role in myocardial damage. In the last decade, increasing evidence has shown that inflammatory cytokines and chemokines play a role in the generation of the inflammatory infiltrate and tissue damage. CCC patients have an increased peripheral production of the inflammatory Th1 cytokines IFN-³ and TNF-± when compared to patients with the asymptomatic/indeterminate form. Moreover, Th1-T cells are the main producers of IFN-³ and TNF-± and are frequently found in CCC myocardial inflammatory infiltrate. Over the past several years, our group has collected evidence that shows several cytokines and chemokines produced in the CCC myocardium may also have a non-immunological pathogenic effect via modulation of gene and protein expression in cardiomyocytes and other myocardial cell types. Furthermore, genetic polymorphisms of cytokine, chemokine and innate immune response genes have been associated with disease progression. We will review the molecular and immunological mechanisms of myocardial damage in human CCC in light of recent findings.

Boosting the suppressive effects of Ascaris suum components in IFN-γ-deficient mice / Potencialização do efeito supressor de componentes do Ascaris suum em camundongos deficientes em IFN-γ

High molecular weight components from Ascaris suum extract suppress ovalbumin-specific immunity in mice. In IFN-γ-deficient mice, ovalbumin-specific delayed-type hypersensitivity reactions are more strongly downregulated by these suppressive components. Here, the cellularity of the delayed-type hypersensitivity reaction in IFN-γ-deficient mice and the increased downregulation induced by Ascaris suum components were analyzed. IL-12p40-dependent neutrophilic influx was predominant. Suboptimal doses of the suppressive fraction from this nematode completely inhibited the hypersensitivity reaction, thus indicating intensification of the immunosuppression under conditions of intense recruitment of IFN-γ-independent neutrophils.

Componentes de alto peso molecular do extrato de Ascaris suum suprimem a imunidade específica à ovalbumina em camundongos. Em camundongos geneticamente deficientes de IFN-γ a reação de hipersensibilidade tardia específica para ovalbumina foi mais fortemente prejudicada por estes componentes supressivos. Aqui, a celularidade da reação de hipersensibilidade tardia em camundongos deficientes de IFN-γ e o incremento na supressão induzida por componentes do Ascaris suum foram analisados. Influxo neutrofílico, dependente de IL-12p40, foi predominante. Dose sub-ótima da fração supressiva do nematódeo inibiu completamente a reação de hipersensibilidade, indicando uma intensificação da imunossupressão em condições de recrutamento intenso de neutrófilos independente de IFN-γ.