BCG masking phenomena might depend on the species of Mycobacterium

Author(s):  
Joana Korablioviene ◽  
Mykolas Mauricas ◽  
Irena Dumalakiene ◽  
Saulius Caplinskas ◽  
Rita Viliene ◽  
...  

AbstractThis study investigated BCG masking dependency on the species of Mycobacterium through the immune response to the mycobacterial region of deletion 1 (RD-1) associated growth affecting proteins (GEP).To evaluate the effects of GEP, 8-week old female BALB/c mice were immunized with either the wild type Mycobacterium bovis (MBGEP) or the ATCC Mycobacterium avium subsp. avium (MAGEP) strain and then subjected to further exposure with Mycobacterium terrae or M. avium sub. avium. Mice immunized with MAGEP and those mice further exposed to M. avium subsp. avium had increased granulocytes (GRA) and monocytes to lymphocytes rate (MLR) compared to control mice. Immunization of mice with GEP induced an antibody response one month after primary immunization, as observed by cross-reactivity. Our findings suggest that MAGEP is related to a latent hypersensitivity reaction and an increased risk of mycobacterial infection susceptibility. According to the results of the present study, previous sensitization with NTM antigens results in varying immune reactions after contact with different NTM argued that masking phenomena may be dependent on the species of Mycobacterium.

2006 ◽  
Vol 74 (11) ◽  
pp. 6092-6099 ◽  
Author(s):  
Alissa A. Chackerian ◽  
Shi-Juan Chen ◽  
Scott J. Brodie ◽  
Jeanine D. Mattson ◽  
Terrill K. McClanahan ◽  
...  

ABSTRACT Interleukin-23 (IL-23), a member of the IL-12 family, is a heterodimeric cytokine that is composed of the p40 subunit of IL-12 plus a unique p19 subunit. IL-23 is critical for autoimmune inflammation, in part due to its stimulation of the proinflammatory cytokine IL-17A. It is less clear, however, if IL-23 is required during the immune response to pathogens. We examined the role of IL-23 during Mycobacterium bovis BCG infection. We found that IL-23 reduces the bacterial burden and promotes granuloma formation when IL-12 is absent. However, IL-23 does not contribute substantially to host resistance when IL-12 is present, as the ability to control bacterial growth and form granulomata is not affected in IL-23p19-deficient mice and mice treated with a specific anti-IL-23p19 antibody. IL-23p19-deficient mice are also able to mount an effective memory response to secondary infection with BCG. While IL-23p19-deficient mice do not produce IL-17A, this cytokine is not necessary for effective control of infection, and antibody blocking of IL-17A in both wild-type and IL-12-deficient mice also has little effect on the bacterial burden. These data suggest that IL-23 by itself does not play an essential role in the protective immune response to BCG infection; however, the presence of IL-23 can partially compensate for the absence of IL-12. Furthermore, neutralization of IL-23 or IL-17A does not increase susceptibility to mycobacterial BCG infection.


2005 ◽  
Vol 73 (1) ◽  
pp. 277-286 ◽  
Author(s):  
Samuel T. Test ◽  
Joyce K. Mitsuyoshi ◽  
Yong Hu

ABSTRACT Complement activation plays a critical role in the immune response to T-cell-dependent and T-cell-independent antigens. However, the effect of conjugation of T-cell-dependent protein carriers to T-cell-independent type 2 antigens on the requirement for complement in the humoral immune response to such antigens remains unknown. We studied the role of complement activation on the antibody response of BALB/c mice immunized with the T-cell-independent type 2 antigen serotype 14 pneumococcal capsular polysaccharide (PPS14), either in unmodified form or conjugated to ovalbumin (OVA). In mice immunized with either PPS14 or PPS14-OVA, depletion of endogenous complement at the time of primary immunization by treatment with cobra venom factor (CVF) diminished serum anti-PPS14 concentrations after primary immunization but enhanced antibody responses after secondary immunization. The secondary immunoglobulin G (IgG) anti-PPS14 antibody response after immunization with PPS14-OVA was especially enhanced by complement depletion, was observed at doses as low as 0.2 μg of antigen, and was maximal when CVF was administered within 2 days of immunization. The avidity and opsonophagocytic functions of IgG anti-PPS14 antibodies were comparable in mice immunized with PPS14-OVA with or without complement depletion. Serum anti-PPS14 antibody concentrations were near normal, and the enhancing effects of CVF treatment on the secondary anti-PPS14 antibody response were also apparent in splenectomized mice immunized with PPS14-OVA. These results demonstrate that complement activation can have distinct effects on the primary and secondary antibody responses to a T-cell-independent type 2 antigen, either unmodified or conjugated to a T-cell-dependent protein carrier. These differences should be taken into consideration when using complement to modulate the immune response to vaccines.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 595-595
Author(s):  
Mridul Agrawal ◽  
Abhishek Niroula ◽  
Pierre Cunin ◽  
Marie McConkey ◽  
Peter G. Kim ◽  
...  

Abstract Background: Gout is a highly prevalent arthritis associated with debilitating joint pain and functional impairment. It is caused by elevated serum uric acid levels (hyperuricemia) and triggered by precipitation of urate crystals in and around joints. Urate crystals are ingested by macrophages and provoke an innate immune response with subsequent secretion of inflammatory cytokines including interleukin 1 beta (IL-1B). Clonal hematopoiesis of indeterminate potential (CHIP) is a precursor to hematologic malignancies defined by somatic mutations in hematopoietic cells that drive clonal expansion and inflammation. Specifically, CHIP is associated with an increased risk of cardiovascular events and can accelerate atherosclerosis. Mutations in TET2, one of the most commonly mutated genes in CHIP, lead to increased expression of IL-1B through inflammasome activation. Here we investigate the role of CHIP in the development of gout using a combination of human genetic studies and mouse models of CHIP. Methods: To determine the clinical association between CHIP and gout, we analyzed exome sequencing and clinical data from >50,000 individuals included in the UK Biobank (UKB) and Mass General Brigham Biobank (MGBB). To test whether mutant blood cells can promote gout, Tet2- and Dnmt3a-deficient mouse models were used. Results: CHIP was more prevalent in individuals with gout than without gout (MGBB: 12.3% vs. 7.9%, P=0.017; UKB: 8.2% vs. 5.8%, P=0.011) and individuals with CHIP were at increased risk of developing gout (UKB: hazard ratio [HR], 1.59; 95% confidence interval [CI], 1.27-2.00; P<0.001). In multivariable analyses, CHIP with variant allele fraction (VAF) ≥10% was associated with higher risk of incident gout compared to no CHIP after adjusting for common gout risk factors (UKB: HR, 1.46; 95% CI, 1.07-2.01; P=0.019). To determine if somatically mutated blood cells directly contribute to the aberrant immune response in gout, we utilized a mouse model of MSU-mediated peritonitis. Compared to control animals, mice with hematopoietic-specific Tet2 deficiency demonstrated markedly increased IL-1B serum levels after injection with MSU (P<0.05). To study gene-specific contributions to joint tissue injury, we established an in vivo model that closely represents the clinical phenotype of gout. Following MSU treatment in situ, Tet2-deficient animals developed exacerbated paw edema compared to wild-type controls (P<0.05). We next generated bone-marrow derived macrophages (BMDM) from Tet2- and Dnmt3a-deficient mice to specifically investigate the MSU-induced cytokine profile in mutant macrophages. Consistent with our in vivo data, IL-1B was the most differentially secreted cytokine after MSU treatment in both Tet2-deficient and Dnmt3a-deficient BMDM compared to wild-type cells (P<0.05). RNA-sequencing confirmed a strong pro-inflammatory gene expression signature of MSU-treated Tet2- and Dnmt3a-deficient macrophages. Finally, we found that pharmacologic inhibition or genetic loss of inflammasome abrogated IL-1B secretion in Tet2- and Dnmt3a-deficient macrophages treated with MSU. Conclusion: CHIP is associated with an increased risk of having and developing gout in human cohorts and distinct mouse models confirm a direct influence of mutant hematopoietic cells on gout-induced inflammation and arthropathy. CHIP may provide a mechanistic explanation for the heterogeneity in clinical symptoms and inflammation due to gout. Our findings substantiate the biologic rationale for interventional strategies directed at CHIP-associated inflammatory conditions beyond cardiovascular disease and thereby define a path for clinical evaluation of targeted therapies for patients with CHIP-positive gout. Disclosures Miller: Foundation Medicine: Consultancy. Neuberg: Pharmacyclics: Research Funding; Madrigal Pharmaceuticals: Other: Stock ownership. Natarajan: Amgen: Research Funding; Apple: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Boston Scientific: Research Funding; Blackstone Life Sciences: Consultancy; Genentech: Consultancy; Foresite Labs: Consultancy. Rao: Janssen: Honoraria, Research Funding; Pfizer: Honoraria; Bristol-Myers Squibb: Honoraria, Research Funding; GlaxoSmithKline: Honoraria; Merck: Honoraria; Scipher Medicine: Honoraria.


2000 ◽  
Vol 68 (12) ◽  
pp. 6946-6953 ◽  
Author(s):  
Julia Wakeham ◽  
Jun Wang ◽  
Zhou Xing

ABSTRACT The current study was designed to investigate the impact of genetic heterogeneity on host immune responses to pulmonary intracellular infection by using two mouse strains of distinct genetic background, C57BL/6 and BALB/c mice, and a model intracellular pathogen,Mycobacterium bovis BCG. Upon infection, compared to C57BL/6 mice, BALB/c mice developed an earlier response of interleukin 12 (IL-12), gamma interferon (IFN-γ), tumor necrosis factor alpha, and macrophage chemoattractive protein 1, and greater neutrophilic influx to the lung by days 7 and 14. However, the level of these cytokines at days 27, 43, and 71 was much lower in BALB/c mice than in C57BL/6 mice. The magnitude of cellular responses was also much lower in the lung of BALB/c mice around day 27. Histologically, while C57BL/6 mice developed lymphocytic granulomas, BALB/c mice displayed atypical granulomas in the lung. Of importance, the level of type 2 cytokines IL-4 and IL-10 remained low and similar in the lung of both C57BL/6 and BALB/c mice throughout. Furthermore, lymphocytes isolated from systemic and local lymphoid tissues of infected BALB/c mice demonstrated a markedly lower antigen-specific IFN-γ recall response. While the number of mycobacterial bacilli recovered from both the lung and spleen of BALB/c mice was similar to that in C57BL/6 mice at day 14, it was higher than that in C57BL/6 mice at day 43. However, it was eventually leveled off to that in C57BL/6 counterparts later. These results suggest the following: (i) genetic heterogeneity can lead to differential innate and adaptive cell-mediated immune responses to primary pulmonary mycobacterial infection; (ii) it is the level of adaptive, but not innate, immune response that is critical to host resistance; and (iii) a lower type 1 immune response in BALB/c mice is not accompanied by a heightened type 2 response during pulmonary mycobacterial infection.


1998 ◽  
Vol 72 (5) ◽  
pp. 4454-4457 ◽  
Author(s):  
Jarasvech Chinsangaram ◽  
Clayton Beard ◽  
Peter W. Mason ◽  
Marla K. Zellner ◽  
Gordon Ward ◽  
...  

ABSTRACT Candidate foot-and-mouth disease (FMD) DNA vaccines designed to produce viral capsids lacking infectious viral nucleic acid were evaluated. Plasmid DNAs containing a portion of the FMDV genome coding for the capsid precursor protein (P1-2A) and wild-type or mutant viral proteinase 3C (plasmids P12X3C or P12X3C-mut, respectively) were constructed. Cell-free translation reactions programmed with pP12X3C (wild-type 3C) and pP12X3C-mut produced a capsid precursor, but only the reactions programmed with the plasmid encoding the functional proteinase resulted in P1-2A processing and capsid formation. Baby hamster kidney (BHK) cells also produced viral capsid proteins when transfected with these plasmids. Plasmid P12X3C was administered to mice by intramuscular, intradermal, and epithelial (gene gun) inoculations. Anti-FMD virus (FMDV) antibodies were detected by radioimmunoprecipitation (RIP) and plaque reduction neutralization assays only in sera of mice inoculated by using a gene gun. When pP12X3C and pP12X3C-mut were inoculated into mice by using a gene gun, both plasmids elicited an antibody response detectable by RIP but only pP12X3C elicited a neutralizing antibody response. These results suggest that capsid formation in situ is required for effective immunization. Expression and stimulation of an immune response was enhanced by addition of an intron sequence upstream of the coding region, while addition of the FMDV internal ribosome entry site or leader proteinase (L) coding region either had no effect or reduced the immune response.


Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1054
Author(s):  
Anna Didkowska ◽  
Monika Krajewska-Wędzina ◽  
Daniel Klich ◽  
Kinga Prolejko ◽  
Blanka Orłowska ◽  
...  

Both bovine tuberculosis (BTB) and paratuberculosis (paraTB) continue to cause significant economic losses in cattle breeding; in addition, their etiological agents have zoonotic potential. Although the diagnostics of both diseases are still being improved, problems still remain, such as the potential for cross-reactivity to the antigens used in tests. The aim of the present study was to confirm whether animals known to harbor Mycobacterium bovis antibodies are at increased risk of yielding positive results in paraTB serotesting and, additionally, to verify the accuracy of three commonly used methods for confirming M. bovis infection: ELISA, the tuberculin skin test (TST), and the presence of gross lesions. Material was collected from 98 dairy cattle suspected of BTB due to TST-positive results. During postmortem examination, gross lesions were assessed visually. Blood, lymph nodes, and TB-suspected organs were collected. Serum was obtained from the collected blood and tested serologically for TB and paraTB. The tissues underwent standard microbiological testing for M. tuberculosis complex. Among the 98 TST-positive individuals, tuberculous gross lesions were detected in 57 (58.1%), MTBC were isolated in 83 (84.7%), and the ELISA test was positive for 21 (21.4%). None of the lesions characteristic for paraTB were detected. The chance of obtaining a positive TB result by ELISA was seven times higher using the ELISA-paraTB method; hence, there is a significant risk of obtaining false-positive serological results for paraTB in M. bovis-infected cattle. However, the hypothesis that infection of M. bovis or prior TST performance may have boosted the host immune response and therefore increased the sensitivity of the paraTB-ELISA cannot be excluded.


2001 ◽  
Vol 45 (11) ◽  
pp. 3059-3064 ◽  
Author(s):  
Jacques Moisan ◽  
Wojciech Wojciechowski ◽  
Claudine Guilbault ◽  
Claude Lachance ◽  
Sergio Di Marco ◽  
...  

ABSTRACT The mouse bcg host resistance gene is known to control the activation of host macrophages for killing of intracellular parasites like Leishmania donovani as well as intracellular bacteria, including Mycobacterium bovisBCG and Salmonella enterica serovar Typhimurium. TheNramp1 gene has been mapped to this locus and affects the efficiency of macrophage activation. It has been shown that imidazoquinoline compounds, including S28463, are able to improve the clearance of a number of intracellular pathogens such as herpes simplex virus 2, human papillomavirus, and Leishmania. The goal of this study was to determine whether S28463 is efficient against infection with another intracellular pathogen, M. bovisBCG, and to determine the molecular basis underlying this effect. To achieve this, B10A.Nramp1 r and B10A.Nramp1 −/− mice were infected with M. bovis BCG and treated with S28463. The bacterial content in the spleen from these mice was assayed by a colony-forming assay. In addition, in vitro experiments were performed using bone marrow-derived macrophage cell lines from these mice. These cells were treated with S28463 and/or gamma interferon (IFN-γ), and nitric oxide (NO) production was measured. Our study was able to show that S28463 acts in synergy with IFN-γ to increase the production of NO in vitro. We were also able to demonstrate that mice that carried the resistant allele of the Nramp1 gene and were infected withM. bovis BCG responded to treatment with S28463, resulting in a decreased bacterial load after 2 weeks of treatment. Mice that do not express the Nramp1 gene responded only to a very large dose of S28463, and the response was not as efficient as that observed in mice carrying a wild-type Nramp1allele. Our data provide evidence for the potential of S28463 as an immunomodulator that may be helpful in designing efficient strategies to improve host defense against mycobacterial infection.


2020 ◽  
pp. 49-57
Author(s):  
S. V. Orlova ◽  
E. A. Nikitina ◽  
L. I. Karushina ◽  
Yu. A. Pigaryova ◽  
O. E. Pronina

Vitamin A (retinol) is one of the key elements for regulating the immune response and controls the division and differentiation of epithelial cells of the mucous membranes of the bronchopulmonary system, gastrointestinal tract, urinary tract, eyes, etc. Its significance in the context of the COVID‑19 pandemic is difficult to overestimate. However, a number of studies conducted in the past have associated the additional intake of vitamin A with an increased risk of developing cancer, as a result of which vitamin A was practically excluded from therapeutic practice in developed countries. Our review highlights the role of vitamin A in maintaining human health and the latest data on its effect on the development mechanisms of somatic pathology.


2018 ◽  
Vol 27 (4) ◽  
pp. 363-369 ◽  
Author(s):  
Gintare Dargiene ◽  
Greta Streleckiene ◽  
Jurgita Skieceviciene ◽  
Marcis Leja ◽  
Alexander Link ◽  
...  

Background & Aims: Previous genome-wide association studies showed that genetic polymorphisms in toll-like receptor 1 (TLR1) and protein kinase AMP-activated alpha 1 catalytic subunit (PRKAA1) genes were associated with gastric cancer (GC) or increased Helicobacter pylori (H. pylori) infection susceptibility. The aim of this study was to evaluate the association between TLR1 and PRKAA1 genes polymorphisms and H.pylori infection, atrophic gastritis (AG) or GC in the European population.Methods: Single-nucleotide polymorphisms (SNPs) were analysed in 511 controls, 340 AG patients and 327 GC patients. TLR1 C>T (rs4833095) and PRKAA1 C>T (rs13361707) were genotyped by the real-time polymerase chain reaction. H. pylori status was determined by testing for anti-H. pylori IgG antibodies in the serum.Results: The study included 697 (59.2%) H. pylori positive and 481 (40.8%) H. pylori negative cases. We observed similar distribution of TLR1 and PRKAA1 alleles and genotypes in H. pylori positive and negative cases. TLR1 and PRKAA1 SNPs were not linked with the risk of AG. TC genotype of TLR1 gene was more prevalent in GC patients compared to the control group (29.7% and 22.3% respectively, p=0.002). Carriers of TC genotype had a higher risk of GC (aOR=1.89, 95% CI: 1.26–2.83, p=0.002). A similar association was observed in a dominant inheritance model for TLR1 gene SNP, where comparison of CC+TC vs. TT genotypes showed an increased risk of GC (aOR=1.86, 95% CI: 1.26–2.75, p=0.002). No association between genetic polymorphism in PRKAA1 gene and GC was observed.Conclusions: TLR1 rs4833095 SNP was associated with an increased risk of GC in a European population, while PRKAA1 rs13361707 genetic variant was not linked with GC. Both genetic polymorphisms were not associated with H. pylori infection susceptibility or the risk of AG.


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