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Iibushi J, Nozawa T, Toh H, Nakagawa I. ATG9B regulates bacterial internalization via actin rearrangement. iScience 2024; 27:109623. [PMID: 38706859 PMCID: PMC11066431 DOI: 10.1016/j.isci.2024.109623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 01/16/2024] [Accepted: 03/26/2024] [Indexed: 05/07/2024] Open
Abstract
Invasive bacterial pathogens are internalized by host cells through endocytosis, which is regulated by a cascade of actin rearrangement signals triggered by host cell receptors or bacterial proteins delivered into host cells. However, the molecular mechanisms that mediate actin rearrangement to promote bacterial invasion are not fully understood. Here, we show that the autophagy-related (ATG) protein ATG9B regulates the internalization of various bacteria by controlling actin rearrangement. ATG knockout screening and knockdown experiments in HeLa cells identified ATG9B as a critical factor for bacterial internalization. In particular, cells with ATG9B knockdown exhibited an accumulation of actin filaments and phosphorylated LIM kinase and cofilin, suggesting that ATG9B is involved in actin depolymerization. Furthermore, the kinase activity of Unc-51-like autophagy-activating kinase 1 was found to regulate ATG9B localization and actin remodeling. These findings revealed a newly discovered function of ATG proteins in bacterial infection rather than autophagy-mediated immunity.
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Affiliation(s)
- Junpei Iibushi
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku 606-8501, Kyoto, Japan
| | - Takashi Nozawa
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku 606-8501, Kyoto, Japan
| | - Hirotaka Toh
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku 606-8501, Kyoto, Japan
| | - Ichiro Nakagawa
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku 606-8501, Kyoto, Japan
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Mycobacterium intracellulare induces a Th17 immune response via M1-like macrophage polarization in canine peripheral blood mononuclear cells. Sci Rep 2022; 12:11818. [PMID: 35821058 PMCID: PMC9276657 DOI: 10.1038/s41598-022-16117-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 07/05/2022] [Indexed: 11/11/2022] Open
Abstract
Mycobacterium avium-intracellulare complex (MAC) is one of the most prevalent pathogenic nontuberculous mycobacteria that cause chronic pulmonary disease. The prevalence of MAC infection has been rising globally in a wide range of hosts, including companion animals. MAC infection has been reported in dogs; however, little is known about interaction between MAC and dogs, especially in immune response. In this study, we investigated the host immune response driven by M. intracellulare using the co-culture system of canine T helper cells and autologous monocyte-derived macrophages (MDMs). Transcriptomic analysis revealed that canine MDMs differentiated into M1-like macrophages after M. intracellulare infection and the macrophages secreted molecules that induced Th1/Th17 cell polarization. Furthermore, canine lymphocytes co-cultured with M. intracellulare-infected macrophages induced the adaptive Th17 responses after 5 days. Taken together, our results indicate that M. intracellulare elicits a Th17 response through macrophage activation in this system. Those findings might help the understanding of the canine immune response to MAC infection and diminishing the potential zoonotic risk in One Health aspect.
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Kim S, Park HE, Park WB, Kim SY, Park HT, Yoo HS. Mycobacterium avium Modulates the Protective Immune Response in Canine Peripheral Blood Mononuclear Cells. Front Cell Infect Microbiol 2021; 10:609712. [PMID: 33520738 PMCID: PMC7840563 DOI: 10.3389/fcimb.2020.609712] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 11/30/2020] [Indexed: 12/31/2022] Open
Abstract
Mycobacterium avium, an opportunistic intracellular pathogen, is a member of the non-tuberculous mycobacteria species. M. avium causes respiratory disease in immunosuppressed individuals and a wide range of animals, including companion dogs and cats. In particular, the number of infected companion dogs has increased, although the underlying mechanism of M. avium pathogenesis in dogs has not been studied. Therefore, in the present study, the host immune response against M. avium in dogs was investigated by transcriptome analysis of canine peripheral blood mononuclear cells. M. avium was shown to induce different immune responses in canine peripheral blood mononuclear cells at different time points after infection. The expression of Th1-associated genes occurred early during M. avium infection, while that of Th17-associated genes increased after 12 h. In addition, the expression of apoptosis-related genes decreased and the abundance of intracellular M. avium increased in monocyte-derived macrophages after infection for 24 h. These results reveal the M. avium induces Th17 immune response and avoids apoptosis in infected canine cells. As the number of M. avium infection cases increases, the results of the present study will contribute to a better understanding of host immune responses to M. avium infection in companion dogs.
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Affiliation(s)
- Suji Kim
- Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
- BK21 FOUR Future Veterinary Medicine Leading Education and Research Center, Seoul National University, Seoul, South Korea
| | - Hyun-Eui Park
- Department of Microbiology, College of Medicine, Gyeongsang National University, Jinju, South Korea
| | - Woo Bin Park
- Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Seo Yihl Kim
- Department of Veterinary Physiology, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Hong-Tae Park
- Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Han Sang Yoo
- Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul, South Korea
- BK21 FOUR Future Veterinary Medicine Leading Education and Research Center, Seoul National University, Seoul, South Korea
- Bio-MAX/N-Bio Institute, Seoul National University, Seoul, South Korea
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To K, Cao R, Yegiazaryan A, Owens J, Venketaraman V. General Overview of Nontuberculous Mycobacteria Opportunistic Pathogens: Mycobacterium avium and Mycobacterium abscessus. J Clin Med 2020; 9:E2541. [PMID: 32781595 PMCID: PMC7463534 DOI: 10.3390/jcm9082541] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 08/02/2020] [Accepted: 08/04/2020] [Indexed: 12/20/2022] Open
Abstract
Nontuberculous mycobacteria (NTM) are emerging human pathogens, causing a wide range of clinical diseases affecting individuals who are immunocompromised and who have underlying health conditions. NTM are ubiquitous in the environment, with certain species causing opportunistic infection in humans, including Mycobacterium avium and Mycobacterium abscessus. The incidence and prevalence of NTM infections are rising globally, especially in developed countries with declining incidence rates of M. tuberculosis infection. Mycobacterium avium, a slow-growing mycobacterium, is associated with Mycobacterium avium complex (MAC) infections that can cause chronic pulmonary disease, disseminated disease, as well as lymphadenitis. M. abscessus infections are considered one of the most antibiotic-resistant mycobacteria and are associated with pulmonary disease, especially cystic fibrosis, as well as contaminated traumatic skin wounds, postsurgical soft tissue infections, and healthcare-associated infections (HAI). Clinical manifestations of diseases depend on the interaction of the host's immune response and the specific mycobacterial species. This review will give a general overview of the general characteristics, vulnerable populations most at risk, pathogenesis, treatment, and prevention for infections caused by Mycobacterium avium, in the context of MAC, and M. abscessus.
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Affiliation(s)
- Kimberly To
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766-1854, USA; (K.T.); (A.Y.)
| | - Ruoqiong Cao
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766-1854, USA; (R.C.); (J.O.)
| | - Aram Yegiazaryan
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766-1854, USA; (K.T.); (A.Y.)
| | - James Owens
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766-1854, USA; (R.C.); (J.O.)
| | - Vishwanath Venketaraman
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766-1854, USA; (R.C.); (J.O.)
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Headley CA, Gerberick A, Mehta S, Wu Q, Yu L, Fadda P, Khan M, Ganesan LP, Turner J, Rajaram MVS. Nontuberculous mycobacterium M. avium infection predisposes aged mice to cardiac abnormalities and inflammation. Aging Cell 2019; 18:e12926. [PMID: 30834643 PMCID: PMC6516181 DOI: 10.1111/acel.12926] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 12/12/2018] [Accepted: 01/20/2019] [Indexed: 12/14/2022] Open
Abstract
Biological aging dynamically alters normal immune and cardiac function, favoring the production of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and increased instances of cardiac distress. Cardiac failure is the primary reason for hospitalization of the elderly (65+ years). The elderly are also increasingly susceptible to developing chronic bacterial infections due to aging associated immune abnormalities. Since bacterial infections compound the rates of cardiac failure in the elderly, and this phenomenon is not entirely understood, the interplay between the immune system and cardiovascular function in the elderly is of great interest. Using Mycobacterium avium, an opportunistic pathogen, we investigated the effect of mycobacteria on cardiac function in aged mice. Young (2-3 months) and old (18-20 months) C57BL/6 mice were intranasally infected with M. avium strain 104, and we compared the bacterial burden, immune status, cardiac electrical activity, pathology, and function of infected mice against uninfected age-matched controls. Herein, we show that biological aging may predispose old mice infected with M. avium to mycobacterial dissemination into the heart tissue and this leads to cardiac dysfunction. M. avium infected old mice had significant dysrhythmia, cardiac hypertrophy, increased recruitment of CD45+ leukocytes, cardiac fibrosis, and increased expression of inflammatory genes in isolated heart tissue. This is the first study to report the effect of mycobacteria on cardiac function in an aged model. Our findings are critical to understanding how nontuberculous mycobacterium (NTM) and other mycobacterial infections contribute to cardiac dysfunction in the elderly population.
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Affiliation(s)
- Colwyn A. Headley
- Department of Microbial Infection and Immunity, College of MedicineThe Ohio State University Wexner Medical CenterColumbusOhio
- Texas Biomedical Research Institute8715 W. Military Dr.San AntonioTX 78227
| | - Abigail Gerberick
- Department of Microbiology, College of MedicineThe Ohio State University Wexner Medical CenterColumbusOhio
| | - Sumiran Mehta
- Department of Microbiology, College of MedicineThe Ohio State University Wexner Medical CenterColumbusOhio
| | - Qian Wu
- Department of Microbial Infection and Immunity, College of MedicineThe Ohio State University Wexner Medical CenterColumbusOhio
| | - Lianbo Yu
- Department of Biomedical Informatics, College of MedicineThe Ohio State University Wexner Medical CenterColumbusOhio
| | - Paolo Fadda
- Department of Biomedical Informatics, College of MedicineThe Ohio State University Wexner Medical CenterColumbusOhio
- Genomics Shared Resource‐Comprehensive Cancer Center, College of MedicineThe Ohio State University Wexner Medical CenterColumbusOhio
| | - Mahmood Khan
- Department Emergency Medicine & Physiology and Cell Biology, College of MedicineThe Ohio State University Wexner Medical CenterColumbusOhio
| | - Latha Prabha Ganesan
- Department of Internal Medicine, College of MedicineThe Ohio State University Wexner Medical CenterColumbusOhio
| | - Joanne Turner
- Department of Microbial Infection and Immunity, College of MedicineThe Ohio State University Wexner Medical CenterColumbusOhio
- Texas Biomedical Research Institute8715 W. Military Dr.San AntonioTX 78227
| | - Murugesan V. S. Rajaram
- Department of Microbial Infection and Immunity, College of MedicineThe Ohio State University Wexner Medical CenterColumbusOhio
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Xiu Y, Zhang H, Wang S, Gan T, Wei M, Zhou S, Chen S. cDNA cloning, characterization, and expression analysis of the Rac1 and Rac2 genes from Cynoglossus semilaevis. FISH & SHELLFISH IMMUNOLOGY 2019; 84:998-1006. [PMID: 30399403 DOI: 10.1016/j.fsi.2018.11.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 10/26/2018] [Accepted: 11/01/2018] [Indexed: 06/08/2023]
Abstract
Rac1 and Rac2, belonging to the small Rho GTPase family, play an important role during the immune responses. In this study, a Rac1 homolog (CsRac1) and a Rac2 homolog (CsRac2) were cloned from the Cynoglossus semilaevis. The full-length of CsRac1 and CsRac2 cDNA was 1219 bp and 1047 bp, respectively. Both CsRac1 and CsRac2 contain a 579 bp open reading frame (ORF) which encoding a 192 amino acids putative protein. The predicted molecular weight of CsRac1 and CsRac2 was 21.41 kDa and 21.35 kDa, and their theoretical pI was 8.50 and 7.91, respectively. Sequence analysis showed that the conserved RHO domain was detected both from amino acid of CsRac1 and CsRac2. Homologous analysis showed that CsRac1 and CsRac2 share high conservation with other counterparts from different species. The CsRac1 and CsRac2 transcript showed wide tissue distribution, in which CsRac1 and CsRac2 exhibit the highest expression level in liver and gill, respectively. The expression level of CsRac1 and CsRac2 fluctuated in the liver and gill tissues at different time points after challenged by Vibrio harveyi. Specifically, CsRac1 and CsRac2 were significantly up-regulated at 48 h and 96 h post injection. Moreover, the knocking down of CsRac1 and CsRac2 in cell line (TSHKC) reduced the expression of CsPAK1, CsIL1-β and CsTNF-α. The present data suggests that CsRac1 and CsRac2 might play important roles in the innate immunity of half-smooth tongue sole.
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Affiliation(s)
- Yunji Xiu
- Marine Science and Engineering College, Qingdao Agricultural University, Qingdao, 266109, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology Yellow Sea Fisheries Research Institute, CAFS, Qingdao, 266071, China; Key Lab of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Qingdao, 266071, China
| | - Hongxiang Zhang
- Marine Science and Engineering College, Qingdao Agricultural University, Qingdao, 266109, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology Yellow Sea Fisheries Research Institute, CAFS, Qingdao, 266071, China; Key Lab of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Qingdao, 266071, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China
| | - Shuangyan Wang
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology Yellow Sea Fisheries Research Institute, CAFS, Qingdao, 266071, China; Key Lab of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Qingdao, 266071, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China
| | - Tian Gan
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology Yellow Sea Fisheries Research Institute, CAFS, Qingdao, 266071, China; Key Lab of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Qingdao, 266071, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China
| | - Min Wei
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology Yellow Sea Fisheries Research Institute, CAFS, Qingdao, 266071, China; Key Lab of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Qingdao, 266071, China
| | - Shun Zhou
- Marine Science and Engineering College, Qingdao Agricultural University, Qingdao, 266109, China
| | - Songlin Chen
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology Yellow Sea Fisheries Research Institute, CAFS, Qingdao, 266071, China; Key Lab of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Qingdao, 266071, China.
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Schwarz DGG, Shoyama FM, Oliveira LL, Sreevatsan S, Moreira MAS. Rapid baso-apical translocation of Mycobacterium avium ssp. paratuberculosis in mammary epithelial cells in the presence of Escherichia coli. J Dairy Sci 2018; 101:6287-6295. [PMID: 29705415 DOI: 10.3168/jds.2017-13945] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 02/20/2018] [Indexed: 01/06/2023]
Abstract
Infection of mammary gland cells with bacterial pathogens begins with adhesion, invasion, and persistence within the cells or systemic distribution. Some bacteria, such as Escherichia coli, are known to causes bovine mastitis, resulting in acute proinflammatory responses in the mammary tissue. Mycobacterium avium ssp. paratuberculosis (MAP), the etiological agent of paratuberculosis, is able to spread to distant organs after crossing intestinal cells, reaching the mammary gland and potentially being released in milk, infecting calves during suckling. Its exit from systemic sites may be influenced by preexisting inflammation such as that caused by E. coli mastitis. Interactions between E. coli and MAP in mammary epithelial cells have not yet been described. In this study, we posited that E. coli-infected bovine mammary epithelial cells would facilitate baso-apical translocation of MAP in an ex vivo model. We showed that the presence of E. coli in a bovine mammary epithelial cell line (MAC-T) increased baso-apical translocation of MAP to the apical side of the cells. Levels were significantly higher 30 min post-infection and decreased at 120 min post-infection. Cells previously infected with E. coli and MAP or with E. coli alone showed a significant increase in IL1B mRNA expression at 120 min. We detected no significant expression of p38 mitogen-activated protein kinase (mapkp38) or IL10, regardless of treatment. Thereby, the presence of E. coli in MAC-T cells alters the translocation of MAP through epithelial cells, enabling its rapid translocation to the cellular surface. Expression of IL1B was shown to influence the apical-basal translocation of MAP at 120 min. Findings from the current study suggest that MAP translocation into milk is likely enhanced by inflammatory states such as those induced during E. coli mastitis. This is the first report demonstrating the effect of E. coli under MAP coinfection in bovine mammary epithelial cells under experimental conditions.
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Affiliation(s)
- D G G Schwarz
- Department of Veterinary, Universidade Federal de Viçosa (UFV), CEP 36570-900, Viçosa, Minas Gerais, Brazil
| | - F M Shoyama
- Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing 48824
| | - L L Oliveira
- Department of General Biology, Universidade Federal de Viçosa (UFV), CEP 36570-900, Viçosa, Minas Gerais, Brazil
| | - S Sreevatsan
- Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing 48824
| | - M A S Moreira
- Department of Veterinary, Universidade Federal de Viçosa (UFV), CEP 36570-900, Viçosa, Minas Gerais, Brazil.
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Bermudez LE, Rose SJ, Everman JL, Ziaie NR. Establishment of a Host-to-Host Transmission Model for Mycobacterium avium subsp. hominissuis Using Caenorhabditis elegans and Identification of Colonization-Associated Genes. Front Cell Infect Microbiol 2018; 8:123. [PMID: 29740544 PMCID: PMC5928147 DOI: 10.3389/fcimb.2018.00123] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 04/05/2018] [Indexed: 11/26/2022] Open
Abstract
Mycobacterium avium subsp. hominissuis (M. avium) is a member of the non-tuberculous mycobacteria (NTM), and is a common cause of lung infection in patients with chronic NTM lung conditions. M. avium is an environmental bacterium believed to be transmitted from environmental sources. In this work we used a recently developed model in Caenorhabditis elegans to ask whether M. avium can be transmitted from host-to-host, and the bacterial genes associated with host colonization. Infection of C. elegans was carried out by placing the nematode in cultured with M. avium. Bacteria eliminated from the intestines of infected C. elegans were used to infect naïve nematodes. In parallel experiments, to identify colonization associated genes, a transposon library of M. avium was screened for the ability to bind to HEp-2 mucosal cells. Thirty clones were identified and five selected clones with impaired adherence to HEp-2 epithelial cells were used to infect C. elegans to determine the degree of colonization. It was determined that M. avium eliminated from infected C. elegans were able to colonize a naïve C. elegans with high efficiency. Thirty of the most adherence-deficient M. avium clones obtained from the HEp-2 cell screening were sequenced to identify the location of the transposon. Many of the genes associated with the bacterial cell wall synthesis were shown to be inactivated in the selected mutants. Five out of the 30 bacterial clones were then used to infect C. elegans. All five mutants had impaired ability to colonize C. elegans compared with the wild type bacteria (decrease of 1.5–2.0 logs, p < 0.05). The limitation of this work is that the model can be used for initial screening, but other more complex systems should be used to confirm the findings. C. elegans can be used as a model to test for M. avium adherence/colonization-associated virulence determinants. All the tested adherence-deficient clones that were examined had impaired ability to colonize the host C. elegans, and some can be potentially used to prevent colonization.
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Affiliation(s)
- Luiz E Bermudez
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States.,Department of Microbiology, College of Science, Oregon State University, Corvallis, OR, United States
| | - Sasha J Rose
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States.,Department of Microbiology, College of Science, Oregon State University, Corvallis, OR, United States
| | - Jamie L Everman
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States.,Department of Microbiology, College of Science, Oregon State University, Corvallis, OR, United States
| | - Navid R Ziaie
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States
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Response of the respiratory mucosal cells to mycobacterium avium subsp. Hominissuis microaggregate. Arch Microbiol 2018; 200:729-742. [PMID: 29383404 DOI: 10.1007/s00203-018-1479-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 11/06/2017] [Accepted: 01/15/2018] [Indexed: 01/10/2023]
Abstract
Mycobacterium avium: subsp. hominissuis (MAH) is an opportunistic pathogen that commonly infects immunocompromised individuals. Recently, we described an invasive phenotypic change MAH undergoes when incubated with lung airway epithelial host cells for 24 h, which is accompanied with microaggregate formation in vitro. The microaggregate phenotype also resulted in higher colonization in the lungs of mice early during infection. Previously, we identified genes highly regulated during microaggregate formation and further characterized the function of two highly upregulated bacterial proteins, mycobacterial binding protein-1 (MBP-1) and mycobacterial inversion protein-1 (MIP-1), which were found to be involved in binding and invasion of the respiratory mucosa. While these studies are valuable in understanding the pathogenesis of MAH, they primarily investigated the bacteria during microaggregate infection without commenting on the differences in the host response to microaggregate and planktonic infection. The bacteria-host interaction between microaggregates and epithelial cells was examined in a variety of assays. Using a transwell polarized epithelial cell model, microaggregates translocated through the monolayer more efficiently than planktonic bacteria at set timepoints. In addition, during infection with microaggregate and planktonic bacteria, host phosphorylated proteins were identified revealing differences in immune response, glutathione synthesis, and apoptosis. The host immune response was further investigated by measuring pro-inflammatory cytokine secretion during microaggregate and planktonic infection of BEAS-2B bronchial epithelial cells. The epithelial cells secreted more CCL5 during infection with microaggregates suggesting that this chemokine may play an important role during microaggregate invasion. Subsequent experiments showed that microaggregates are formed more efficiently in the presence of CCL5, suggesting that MAH had evolved a strategy to use the host response in its benefit. Collectively, this study establishes the different nature of infection by planktonic bacteria and microaggregates.
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Ribeiro GM, Matsumoto CK, Real F, Teixeira D, Duarte RS, Mortara RA, Leão SC, de Souza Carvalho-Wodarz C. Increased survival and proliferation of the epidemic strain Mycobacterium abscessus subsp. massiliense CRM0019 in alveolar epithelial cells. BMC Microbiol 2017; 17:195. [PMID: 28903728 PMCID: PMC5598063 DOI: 10.1186/s12866-017-1102-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 09/05/2017] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Outbreaks of infections caused by rapidly growing mycobacteria have been reported worldwide generally associated with medical procedures. Mycobacterium abscessus subsp. massiliense CRM0019 was obtained during an epidemic of postsurgical infections and was characterized by increased persistence in vivo. To better understand the successful survival strategies of this microorganism, we evaluated its infectivity and proliferation in macrophages (RAW and BMDM) and alveolar epithelial cells (A549). For that, we assessed the following parameters, for both M. abscessus CRM0019 as well as the reference strain M. abscessus ATCC 19977: internalization, intracellular survival for up 3 days, competence to subvert lysosome fusion and the intracellular survival after cell reinfection. RESULTS CRM0019 and ATCC 19977 strains showed the same internalization rate (approximately 30% after 6 h infection), in both A549 and RAW cells. However, colony forming units data showed that CRM0019 survived better in A549 cells than the ATCC 19977 strain. Phagosomal characteristics of CRM0019 showed the bacteria inside tight phagosomes in A549 cells, contrasting to the loosely phagosomal membrane in macrophages. This observation holds for the ATCC 19977 strain in both cell types. The competence to subvert lysosome fusion was assessed by acidification and acquisition of lysosomal protein. For M. abscessus strains the phagosomes were acidified in all cell lines; nevertheless, the acquisition of lysosomal protein was reduced by CRM0019 compared to the ATCC 19977 strain, in A549 cells. Conversely, in macrophages, both M. abscessus strains were located in mature phagosomes, however without bacterial death. Once recovered from macrophages M. abscessus could establish a new intracellular infection. Nevertheless, only CRM0019 showed a higher growth rate in A549, increasing nearly 10-fold after 48 and 72 h. CONCLUSION M. abscessus CRM0019 creates a protective and replicative niche in alveolar epithelial cells mainly by avoiding phagosome maturation. Once recovered from infected macrophages, CRM0019 remains infective and displays greater intracellular growth in A549 cells compared to the ATCC 19977 strain. This evasion strategy in alveolar epithelial cells may contribute to the long survival of the CRM0019 strain in the host and thus to the inefficacy of in vivo treatment.
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Affiliation(s)
- Giovanni Monteiro Ribeiro
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Cristianne Kayoko Matsumoto
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Fernando Real
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil.,Laboratoire Entrée muqueuse du VIH et Immunité muqueuse, Department Infection, Immunité et Inflammation, Institut Cochin, Paris, France
| | - Daniela Teixeira
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Rafael Silva Duarte
- Laboratório de Micobactérias, Instituto de Microbiologia Professor Paulo de Góes, Cidade Universitária, Rio de Janeiro, Brazil
| | - Renato Arruda Mortara
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Sylvia Cardoso Leão
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Cristiane de Souza Carvalho-Wodarz
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil. .,Department of Drug Delivery, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany.
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Gold MC, Napier RJ, Lewinsohn DM. MR1-restricted mucosal associated invariant T (MAIT) cells in the immune response to Mycobacterium tuberculosis. Immunol Rev 2015; 264:154-66. [PMID: 25703558 DOI: 10.1111/imr.12271] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The intracellular pathogen Mycobacterium tuberculosis (Mtb) and its human host have long co-evolved. Although the host cellular immune response is critical to the control of the bacterium information on the specific contribution of different immune cell subsets in humans is incomplete. Mucosal associated invariant T (MAIT) cells are a prevalent and unique T-cell population in humans with the capacity to detect intracellular infection with bacteria including Mtb. MAIT cells detect bacterially derived metabolites presented by the evolutionarily conserved major histocompatibility complex-like molecule MR1. Here, we review recent advances in our understanding of this T-cell subset and address the potential roles for MR1-restricted T cells in the control, diagnosis, and therapy of tuberculosis.
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Affiliation(s)
- Marielle C Gold
- Pulmonary and Critical Care Medicine, Oregon Health and Science University, Portland, OR, USA; VA Portland Health Care System (VAPORHCS), Portland, OR, USA; Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR, USA
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Citalán-Madrid AF, García-Ponce A, Vargas-Robles H, Betanzos A, Schnoor M. Small GTPases of the Ras superfamily regulate intestinal epithelial homeostasis and barrier function via common and unique mechanisms. Tissue Barriers 2013; 1:e26938. [PMID: 24868497 PMCID: PMC3942330 DOI: 10.4161/tisb.26938] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 10/21/2013] [Accepted: 10/24/2013] [Indexed: 12/11/2022] Open
Abstract
The intestinal epithelium forms a stable barrier protecting underlying tissues from pathogens in the gut lumen. This is achieved by specialized integral membrane structures such as tight and adherens junctions that connect neighboring cells and provide stabilizing links to the cytoskeleton. Junctions are constantly remodeled to respond to extracellular stimuli. Assembly and disassembly of junctions is regulated by interplay of actin remodeling, endocytotic recycling of junctional proteins, and various signaling pathways. Accumulating evidence implicate small G proteins of the Ras superfamily as important signaling molecules for the regulation of epithelial junctions. They function as molecular switches circling between an inactive GDP-bound and an active GTP-bound state. Once activated, they bind different effector molecules to control cellular processes required for correct junction assembly, maintenance and remodelling. Here, we review recent advances in understanding how GTPases of the Rho, Ras, Rab and Arf families contribute to intestinal epithelial homeostasis.
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Affiliation(s)
- Alí Francisco Citalán-Madrid
- Department of Molecular Biomedicine; Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav del IPN); Mexico City, Mexico
| | - Alexander García-Ponce
- Department of Molecular Biomedicine; Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav del IPN); Mexico City, Mexico
| | - Hilda Vargas-Robles
- Department of Molecular Biomedicine; Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav del IPN); Mexico City, Mexico
| | - Abigail Betanzos
- Department of Infectomics and Molecular Pathogenesis; Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav del IPN); Mexico City, Mexico
| | - Michael Schnoor
- Department of Molecular Biomedicine; Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav del IPN); Mexico City, Mexico
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Kim SY, Sohn H, Choi GE, Cho SN, Oh T, Kim HJ, Whang J, Kim JS, Byun EH, Kim WS, Min KN, Kim JM, Shin SJ. Conversion of Mycobacterium smegmatis to a pathogenic phenotype via passage of epithelial cells during macrophage infection. Med Microbiol Immunol 2011; 200:177-91. [PMID: 21359846 DOI: 10.1007/s00430-011-0190-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Indexed: 01/18/2023]
Abstract
Mycobacteria encounter many different cells during infection within their hosts. Although alveolar epithelial cells play an essential role in host defense as the first cells to be challenged upon contact with mycobacteria, they may contribute to the acquisition of mycobacterial virulence by increasing the expression of virulence or adaptation factors prior to being ingested by macrophages on the side of pathogens. From this aspect, the enhanced virulence of nonpathogenic Mycobacterium smegmatis (MSM) passed through human alveolar A549 epithelial cells (A-MSM) was compared to the direct infection of MSM (D-MSM) in THP-1 macrophages and mouse models. The intracellular growth rate and cytotoxicity of A-MSM were significantly increased in THP-1 macrophages. In addition, compared to D-MSM, A-MSM induced relatively greater interleukin (IL)-1β, IL-6, IL-8, IL-12, TNF-α, MIP-1α, and MCP-1 in THP-1 macrophages. As a next step, a more persistent A-MSM infection was observed in a murine infection model with the development of granulomatous inflammation. Finally, 58 genes induced specifically in A-MSM were partially identified by differential expression using a customized amplification library. These gene expressions were simultaneously maintained in THP-1 infection but no changes were observed in D-MSM. Bioinformatic analysis revealed that these genes are involved mainly in bacterial metabolism including energy production and conversion, carbohydrate, amino acid, and lipid transport, and metabolisms. Conclusively, alveolar epithelial cells promoted the conversion of MSM to the virulent phenotype prior to encountering macrophages by activating the genes required for intracellular survival and presenting its pathogenicity.
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Affiliation(s)
- Su-Young Kim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
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Bach H, Ko HH, Raizman EA, Attarian R, Cho B, Biet F, Enns R, Bressler B. Immunogenicity of Mycobacterium avium subsp. paratuberculosis proteins in Crohn's disease patients. Scand J Gastroenterol 2011; 46:30-9. [PMID: 20735153 DOI: 10.3109/00365521.2010.513061] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
UNLABELLED The association between Mycobacterium avium subsp. paratuberculosis (MAP) and Crohn's disease (CD) is supported by several studies reporting the detection or isolation of MAP from human tissues, but a direct association is still debatable. OBJECTIVE To evaluate the survival of MAP in human intestinal cells and to measure the presence of antibodies against two mycobacterial proteins necessary for the survival of the bacterium in the sera of CD patients. MATERIAL AND METHODS Human-derived intestinal cells were infected with three isolates of MAP and the survival of the microorganism was determined. The presence of antibodies against protein tyrosine phosphatase A (PtpA) and protein kinase G (two proteins secreted within the host in the early stages of the invasion) in the sera of CD patients was evaluated. Sera of 20 CD patients and 20 controls were collected and the presence of the antibodies was assayed using enzyme-linked immunosorbent assay (ELISA). Secretion of the PtpA in vivo was visualized by immunostaining. RESULTS MAP survived in intestinal cells, and immunostaining of PtpA showed that the protein was secreted within these cells. Wilcoxon rank sum test revealed that CD patient sera had significantly higher titer of antibodies specific for both of these antigens compared to controls. ELISA results for either protein were not statistically different between men and women. CONCLUSIONS The presence of specific antibodies against mycobacterial proteins essential for establishing an infection in the host suggests that MAP can potentially be active in CD patients, and a serological test can be developed for early detection of MAP in CD patients.
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Affiliation(s)
- Horacio Bach
- Department of Medicine, Division of Infectious Diseases, University of British Columbia, Vancouver, British Columbia, Canada.
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Agarwal V, Asmat TM, Luo S, Jensch I, Zipfel PF, Hammerschmidt S. Complement regulator Factor H mediates a two-step uptake of Streptococcus pneumoniae by human cells. J Biol Chem 2010; 285:23486-95. [PMID: 20504767 DOI: 10.1074/jbc.m110.142703] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Streptococcus pneumoniae, a human pathogen, recruits complement regulator factor H to its bacterial cell surface. The bacterial PspC protein binds Factor H via short consensus repeats (SCR) 8-11 and SCR19-20. In this study, we define how bacterially bound Factor H promotes pneumococcal adherence to and uptake by epithelial cells or human polymorphonuclear leukocytes (PMNs) via a two-step process. First, pneumococcal adherence to epithelial cells was significantly reduced by heparin and dermatan sulfate. However, none of the glycosaminoglycans affected binding of Factor H to pneumococci. Adherence of pneumococci to human epithelial cells was inhibited by monoclonal antibodies recognizing SCR19-20 of Factor H suggesting that the C-terminal glycosaminoglycan-binding region of Factor H mediates the contact between pneumococci and human cells. Blocking of the integrin CR3 receptor, i.e. CD11b and CD18, of PMNs or CR3-expressing epithelial cells reduced significantly the interaction of pneumococci with both cell types. Similarly, an additional CR3 ligand, Pra1, derived from Candida albicans, blocked the interaction of pneumococci with PMNs. Strikingly, Pra1 inhibited also pneumococcal uptake by lung epithelial cells but not adherence. In addition, invasion of Factor H-coated pneumococci required the dynamics of host-cell actin microfilaments and was affected by inhibitors of protein-tyrosine kinases and phosphatidylinositol 3-kinase. In conclusion, pneumococcal entry into host cells via Factor H is based on a two-step mechanism. The first and initial contact of Factor H-coated pneumococci is mediated by glycosaminoglycans expressed on the surface of human cells, and the second step, pneumococcal uptake, is integrin-mediated and depends on host signaling molecules such as phosphatidylinositol 3-kinase.
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Affiliation(s)
- Vaibhav Agarwal
- Department of Genetics of Microorganisms, Institute for Genetics and Functional Genomics, Ernst Moritz Arndt University of Greifswald, Friedrich-Ludwig-Jahn-Strasse 15a, D-17487 Greifswald, Germany
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16
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Li YJ, Danelishvili L, Wagner D, Petrofsky M, Bermudez LE. Identification of virulence determinants of Mycobacterium avium that impact on the ability to resist host killing mechanisms. J Med Microbiol 2010; 59:8-16. [PMID: 19745033 PMCID: PMC2887559 DOI: 10.1099/jmm.0.012864-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Mycobacterium avium is an opportunistic pathogen associated with pulmonary disease in non-AIDS patients and disseminated infection in patients with AIDS. The chief route of infection is by colonization and invasion of the mucosa of the gastrointestinal tract, but infection through the respiratory route also occurs. After crossing the mucosa, M. avium infects and replicates within tissue macrophages. To identify M. avium genes required for survival in vivo, a library of signature-tagged transposon mutants was constructed and screened for clones attenuated in mice. Thirty-two clones were found to be attenuated for their virulence, from which eleven were sequenced and tested further. All the mutants studied grew similarly in vitro to the wild-type MAC104. Ten mutants were tested individually in mice, confirming the attenuated phenotype. MAV_2450, a polyketide synthase homologue to Mycobacterium tuberculosis pks12, was identified. STM5 and STM10 genes (encoding two hypothetical proteins MAV_4292 and MAV_4012) were associated with susceptibility to oxidative products. Mutants MAV_2450, MAV_4292, MAV_0385 and MAV_4264 live in macrophage vacuoles with acidic pH (below 6.9). Mutants MAV_4292, MAV_0385 and MAV_4264 were susceptible to nitric oxide in vitro. The study of individual mutants can potentially lead to new knowledge about M. avium pathogenic mechanisms.
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Affiliation(s)
- Yong-jun Li
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA
| | - Lia Danelishvili
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA
| | - Dirk Wagner
- Department of Internal Medicine II – Infectious Diseases, University of Freiburg, 79106 Freiburg, Germany
| | - Mary Petrofsky
- Kuzell Institute, California Pacific Medical Center Research Institute, San Francisco, CA, USA
| | - Luiz E. Bermudez
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA
- Department of Microbiology, College of Science, Oregon State University, Corvallis, OR, USA
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Pott J, Basler T, Duerr CU, Rohde M, Goethe R, Hornef MW. Internalization-dependent recognition of Mycobacterium avium ssp. paratuberculosis by intestinal epithelial cells. Cell Microbiol 2009; 11:1802-15. [PMID: 19681906 DOI: 10.1111/j.1462-5822.2009.01372.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mycobacterium avium ssp. paratuberculosis (MAP) is the causative agent of Johne's disease, a highly prevalent chronic intestinal infection in domestic and wildlife ruminants. The microbial pathogenesis of MAP infection has attracted additional attention due to an association with the human enteric inflammatory Crohn's disease. MAP is acquired by the faecal-oral route prompting us to study the interaction with differentiated intestinal epithelial cells. MAP was rapidly internalized and accumulated in a late endosomal compartment. In contrast to other opportunistic mycobacteria or M. bovis, MAP induced significant epithelial activation as indicated by a NF-kappaB-independent but Erk-dependent chemokine secretion. Surprisingly, MAP-induced chemokine production was completely internalization-dependent as inhibition of Rac-dependent bacterial uptake abolished epithelial activation. In accordance, innate immune recognition of MAP by differentiated intestinal epithelial cells occurred through the intracellularly localized pattern recognition receptors toll-like receptor 9 and NOD1 with signal transduction via the adaptor molecules MyD88 and RIP2. The internalization-dependent innate immune activation of intestinal epithelial cells is in contrast to the stimulation of professional phagocytes by extracellular bacterial constituents and might significantly contribute to the histopathological changes observed during enteric MAP infection.
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Affiliation(s)
- Johanna Pott
- Institute for Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
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18
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Agarwal V, Hammerschmidt S. Cdc42 and the phosphatidylinositol 3-kinase-Akt pathway are essential for PspC-mediated internalization of pneumococci by respiratory epithelial cells. J Biol Chem 2009; 284:19427-36. [PMID: 19473971 DOI: 10.1074/jbc.m109.003442] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The pneumococcal surface protein C (PspC) is a major adhesin of Streptococcus pneumoniae, the cause of lobar pneumonia and invasive diseases. PspC interacts in a human-specific manner with the ectodomain of the human polymeric immunoglobulin receptor (pIgR) produced by respiratory epithelial cells. By adopting the retrograde machinery of human pIgR, this protein-protein interaction promotes colonization and transcytosis across the epithelial layer. Here, we explored the role of Rho family guanosine triphosphatases (GTPases), phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt) for ingestion of pneumococci via the human pIgR. Inhibition experiments suggested that the host-cell actin microfilaments and microtubules are essential for this pneumococcal uptake mechanism. By using specific GTPase-modifying toxins, inhibitors, and GTPase expression constructs we demonstrate that Cdc42, but not Rac1 and RhoA are involved in PspC-mediated invasion of pneumococci into host cells. Accordingly, Cdc42 is time-dependently activated during ingestion of pneumococci. In addition, PI3K and Akt are essential for ingestion of pneumococci by respiratory epithelial cells via the PspC-pIgR interaction. The subunit p85alpha of PI3K and Akt was activated during the infection process. Moreover, Akt activation upon pneumococcal invasion depends on PI3K. In conclusion, our results illustrate for the first time key signaling molecules of host cells that are required for PspC-pIgR-mediated invasion of pneumococci into epithelial cells. This unique and specific bacterial entry process is dependent on the cooperation and activation of Rho family GTPase Cdc42, PI3K, and Akt.
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Affiliation(s)
- Vaibhav Agarwal
- Department of Genetics of Microorganisms, Institute for Genetics and Functional Genomics, Ernst Moritz Arndt University of Greifswald, Friedrich-Ludwig-Jahn-Strasse 15a, Greifswald D-17487, Germany
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19
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Jia A, Zhang XH. cDNA cloning, characterization, and expression analysis of the Rac1 gene from Scophthalmus maximus. Comp Biochem Physiol B Biochem Mol Biol 2009; 154:80-4. [PMID: 19426825 DOI: 10.1016/j.cbpb.2009.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 05/05/2009] [Accepted: 05/05/2009] [Indexed: 12/23/2022]
Abstract
Rac1 is a small GTP-binding protein that belongs to the Rho small GTPases, which are important signaling molecules that regulate the dynamics of the actin cytoskeleton and mediate changes in cell morphology and motility. The EST sequence of Rac1 from turbot (Scophthalmus maximus L.) was obtained from a subtractive cDNA library previously. In this study, the full-length cDNA sequence of turbot Rac1 was obtained, which was 2420 nucleotides (nt) encoding a protein of 192 amino acids, with a putative molecular weight of 21.3 kDa. At the amino-acid level, turbot Rac1 was highly conserved to previously characterized GTPases of Rac sub-family, and was nearly identical to human Rac1 (95.3% identity). Quantitative real-time PCR demonstrated that the Rac1 was constitutively expressed in all tissues examined, but at different levels. Upon challenge with Vibrio harveyi, the expression level of Rac1 fluctuated in the liver at different time points. In the head kidney, its expression level decreased to the lowest at 4 h, and then increased to the background level at 24 h. The remarkable degree of evolutionary conservation observed in turbot Rac1 primary structure together with its changing in expression level upon challenge suggested a functionally important role for this Rho family member in the immune response.
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Affiliation(s)
- Airong Jia
- Department of Marine Biology, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
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Specificity of the zebrafish host transcriptome response to acute and chronic mycobacterial infection and the role of innate and adaptive immune components. Mol Immunol 2009; 46:2317-32. [PMID: 19409617 DOI: 10.1016/j.molimm.2009.03.024] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Accepted: 03/28/2009] [Indexed: 12/16/2022]
Abstract
Pathogenic mycobacteria have the ability to survive within macrophages and persist inside granulomas. The complex host-pathogen interactions that determine the outcome of a mycobacterial infection process result in marked alterations of the host gene expression profile. Here we used the zebrafish model to investigate the specificity of the host response to infections with two mycobacterium strains that give distinct disease outcomes: an acute disease with early lethality or a chronic disease with granuloma formation, caused by Mycobacterium marinum strains Mma20 and E11, respectively. We performed a microarray study of different stages of disease progression in adult zebrafish and found that the acute and the chronic strains evoked partially overlapping host transcriptome signatures, despite that they induce profoundly different disease phenotypes. Both strains affected many signaling cascades, including WNT and TLR pathways. Interestingly, the strongest differences were observed at the initial stage of the disease. The immediate response to the acute strain was characterized by higher expression of genes encoding MHC class I proteins, matrix metalloproteinases, transcription factors, cytokines and other common immune response proteins. In contrast, small GTPase and histone gene groups showed higher expression in response to the chronic strain. We also found that nearly 1000 mycobacterium-responsive genes overlapped between the expression signatures of infected zebrafish adults and embryos at different stages of granuloma formation. Since adult zebrafish possess an adaptive immune system similar to mammals and zebrafish embryos rely solely on innate immunity, this overlap indicates a major contribution of the innate component of the immune system in the response to mycobacterial infection. Taken together, our comparison of the transcriptome responses involved in acute versus chronic infections and in the embryonic versus adult situation provides important new leads for investigating the mechanism of mycobacterial pathogenesis.
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Mycobacterium avium genes MAV_5138 and MAV_3679 are transcriptional regulators that play a role in invasion of epithelial cells, in part by their regulation of CipA, a putative surface protein interacting with host cell signaling pathways. J Bacteriol 2008; 191:1132-42. [PMID: 19060135 DOI: 10.1128/jb.01359-07] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The Mycobacterium avium complex (MAC) is an important group of opportunistic pathogens for birds, cattle, swine, and immunosuppressed humans. Although invasion of epithelial cells lining the intestine is the chief point of entry for these organisms, little is known about the mechanisms by which members of the MAC are taken up by these cells. Studies with M. avium have shown that cytoskeletal rearrangement via activation of the small G-protein Cdc42 is involved and that this activation is regulated in part by the M. avium fadD2 gene. The fadD2 gene indirectly regulates a number of genes upon exposure to HEp-2 cells, including transcriptional regulators, membrane proteins, and secreted proteins. Overexpression of two fadD2-associated regulators (MAV_5138 and MAV_3679) led to increased invasion of HEp-2 cells, as well as altered expression of other genes. The protein product of one of the regulated genes, named CipA, has domains that resemble the PXXP motif of human Piccolo proteins, which bind SH3 domains in proteins involved in the scaffold complex formed during cytoskeletal rearrangement. Although CipA was not detected in the cytoplasm of HEp-2 cells exposed to M. avium, the recombinant protein was shown to be potentially expressed on the surface of Mycobacterium smegmatis incubated with HEp-2 cells and, possibly, to interact with human Cdc42. The interaction was then confirmed by showing that CipA activates Cdc42. These results suggest that members of the M. avium complex have a novel mechanism for activating cytoskeletal rearrangement, prompting uptake by host epithelial cells, and that this mechanism is regulated in part by fadD2, MAV_5138, and MAV_3679.
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Lelong-Rebel IH, Piemont Y, Fabre M, Rebel G. Mycobacterium avium–intracellulare contamination of mammalian cell cultures. In Vitro Cell Dev Biol Anim 2008; 45:75-90. [DOI: 10.1007/s11626-008-9143-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Accepted: 08/25/2008] [Indexed: 01/15/2023]
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The Mycobacterium avium subsp. paratuberculosis MAP3464 gene encodes an oxidoreductase involved in invasion of bovine epithelial cells through the activation of host cell Cdc42. Infect Immun 2007; 76:170-8. [PMID: 17938223 DOI: 10.1128/iai.01913-06] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Mycobacterium avium subsp. paratuberculosis infection of cattle takes place through the intestinal mucosa. To identify M. avium subsp. paratuberculosis genes associated with the invasion of bovine epithelial cells in vitro, we screened a library of transposon mutants. Several mutants of M. avium subsp. paratuberculosis were identified which invaded Madin-Darby bovine kidney (MDBK) epithelial cells less efficiently than wild-type (wt) M. avium subsp. paratuberculosis. The deltaOx mutant had the transposon located in the MAP3464 gene, a putative oxidoreductase gene whose expression is upregulated upon bacterial contact with MDBK cells. Complete restoration of invasion comparable to that for the wt bacterium was achieved by introducing a copy of the complete oxidoreductase operon into the deltaOx mutant. Immunoprecipitation and Western blot analysis indicated that wt M. avium subsp. paratuberculosis activates Cdc42 and RhoA pathways of internalization 15 and 60 min after infection of the host cell, respectively. The deltaOx mutant, however, failed to activate the Cdc42 pathway. To determine whether an M. avium subsp. paratuberculosis protein delivered to the host cell mediates the entry of the wt bacterium by activation of the Cdc42 pathway, affinity precipitation of active Cdc42 from MDBK-infected cells followed by mass spectrometry was carried out. We identified a 17-amino-acid bacterial peptide associated with the Cdc42 of cells infected with wt M. avium subsp. paratuberculosis but not with the deltaOx mutant. The sequence of the peptide matches MAP3985c, a hypothetical protein, possibly functioning as a putative Cdc42 effector. These findings reveal a novel signaling pathway activated during M. avium subsp. paratuberculosis entry that links the product of MAP3464 gene to activation of Cdc42 in the host cell.
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Harriff MJ, Bermudez LE, Kent ML. Experimental exposure of zebrafish, Danio rerio (Hamilton), to Mycobacterium marinum and Mycobacterium peregrinum reveals the gastrointestinal tract as the primary route of infection: a potential model for environmental mycobacterial infection. JOURNAL OF FISH DISEASES 2007; 30:587-600. [PMID: 17850575 DOI: 10.1111/j.1365-2761.2007.00839.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The natural route by which fish become infected with mycobacteria is unknown. Danio rerio (Hamilton) were exposed by bath immersion and intubation to Mycobacterium marinum and Mycobacterium peregrinum isolates obtained from diseased zebrafish. Exposed fish were collected over the course of 8 weeks and examined for the presence of mycobacteriosis. Mycobacteria were consistently cultured from the intestines, and often from the livers and spleens of fish exposed by both methods. Mycobacteria were not observed in the gills. Histological analysis revealed that fish infected with M. marinum often developed granulomas accompanied by clinical signs of mycobacteriosis, while infection with M. peregrinum infrequently led to clinical signs of disease. Passage of the bacteria through environmental amoebae (Acanthamoeba castellani) was associated with increased growth of M. peregrinum over the course of 8 weeks, when compared to infection with the bacteria not passed through amoebae. The results provide evidence that zebrafish acquire mycobacteria primarily through the intestinal tract, resulting in mycobacterial dissemination.
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Affiliation(s)
- M J Harriff
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA
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25
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Is alpha-dystroglycan the missing link in the mechanism of enterocyte uptake and translocation of Mycobacterium avium paratuberculosis? Med Hypotheses 2007; 70:369-74. [PMID: 17597306 DOI: 10.1016/j.mehy.2007.05.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Accepted: 05/03/2007] [Indexed: 12/28/2022]
Abstract
Mycobacterium avium paratuberculosis (MAP) is an important animal pathogen with a potential role in human disease. MAP is recognized to cause severe diarrheas and wasting syndrome in patients infected by the human immuno-deficiency virus. Recently, there is also growing evidence that MAP is somehow involved into the patho-mechanisms of Crohn's disease. However, the mechanism how MAP binds to the intestinal mucosa and consecutively invades and translocates the intestinal epithelial cells is still unknown. Here it is suggested, that MAP enters the intestinal cells via the dystrophin-glycoprotein-complex (DGC) in a similar manner as known from Mycobacterium tuberculosis in peripheral Schwann cell invasion. Recent approaches to identify the mechanism of intestinal MAP uptake revealed several molecules which are therefore thought to be involved in MAP cell invasion. Nevertheless, there is no comprehensive connection so far to link all identified mechanisms together. Since the DGC has a direct association to all identified molecules and mechanisms and therefore seems to be the missing link, it is hypothesized now, that MAP binds to alpha-dystroglycan and exploits an endogenous recycling mechanism to control the dystroglycan expression levels to enter and translocate the intestinal cells. Since there are options to modify dystroglycan this might be a potential new target to prevent or even treat intestinal MAP infections.
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Krause-Gruszczynska M, Rohde M, Hartig R, Genth H, Schmidt G, Keo T, König W, Miller WG, Konkel ME, Backert S. Role of the small Rho GTPases Rac1 and Cdc42 in host cell invasion of Campylobacter jejuni. Cell Microbiol 2007; 9:2431-44. [PMID: 17521326 DOI: 10.1111/j.1462-5822.2007.00971.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Host cell invasion of the food-borne pathogen Campylobacter jejuni is one of the primary reasons of tissue damage in humans but molecular mechanisms are widely unclear. Here, we show that C. jejuni triggers membrane ruffling in the eukaryotic cell followed by invasion in a very specific manner first with its tip followed by the flagellar end. To pinpoint important signalling events involved in the C. jejuni invasion process, we examined the role of small Rho family GTPases. Using specific GTPase-modifying toxins, inhibitors and GTPase expression constructs we show that Rac1 and Cdc42, but not RhoA, are involved in C. jejuni invasion. In agreement with these observations, we found that internalization of C. jejuni is accompanied by a time-dependent activation of both Rac1 and Cdc42. Finally, we show that the activation of these GTPases involves different host cell kinases and the bacterial fibronectin-binding protein CadF. Thus, CadF is a bifunctional protein which triggers bacterial binding to host cells as well as signalling leading to GTPase activation. Collectively, our results suggest that C. jejuni invade host target cells by a unique mechanism and the activation of the Rho GTPase members Rac1 and Cdc42 plays a crucial role in this entry process.
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Affiliation(s)
- Malgorzata Krause-Gruszczynska
- Department of Medical Microbiology, Otto von Guericke University Magdeburg, Leipziger Str. 44, D-39120 Magdeburg, Germany
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27
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Yamazaki Y, Danelishvili L, Wu M, Hidaka E, Katsuyama T, Stang B, Petrofsky M, Bildfell R, Bermudez LE. The ability to form biofilm influences Mycobacterium avium invasion and translocation of bronchial epithelial cells. Cell Microbiol 2006; 8:806-14. [PMID: 16611229 DOI: 10.1111/j.1462-5822.2005.00667.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Organisms of the Mycobacterium avium complex (MAC) are widely distributed in the environment, form biofilms in water pipes and potable water tanks, and cause chronic lung infections in patients with chronic obstructive pulmonary disease and cystic fibrosis. Pathological studies in patients with pulmonary MAC infection revealed granulomatous inflammation around bronchi and bronchioles. BEAS-2B human bronchial epithelial cell line was used to study MAC invasion. MAC strain A5 entered polarized BEAS-2B cells with an efficiency of 0.1 +/- 0.03% in 2 h and 11.3 +/- 4.0% in 24 h. In contrast, biofilm-deficient transposon mutants 5G4, 6H9 and 9B5 showed impaired invasion. Bacteria exposed to BEAS-2B cells for 24 h had greater ability to invade BEAS-2B cells compared with bacteria incubated in broth. M. avium had no impact on the monolayer transmembrane resistance. Scanning electron microscopy showed that MAC A5 forms aggregates on the surface of BEAS-2B cell monolayers, and transmission electron microscopy evidenced MAC within vacuoles in BEAS-2B cells. Cells infected with the 5G4 mutant, however, showed significantly fewer bacteria and no aggregates on the cell surface. Mutants had impaired ability to cause infection in mice, as well. The ability to form biofilm appeared to be associated with the invasiveness of MAC A5.
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Affiliation(s)
- Yoshitaka Yamazaki
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA
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28
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Patel D, Danelishvili L, Yamazaki Y, Alonso M, Paustian ML, Bannantine JP, Meunier-Goddik L, Bermudez LE. The ability of Mycobacterium avium subsp. paratuberculosis to enter bovine epithelial cells is influenced by preexposure to a hyperosmolar environment and intracellular passage in bovine mammary epithelial cells. Infect Immun 2006; 74:2849-55. [PMID: 16622223 PMCID: PMC1459753 DOI: 10.1128/iai.74.5.2849-2855.2006] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Mycobacterium avium subsp. paratuberculosis is the cause of Johne's disease in cattle and other ruminants. M. avium subsp. paratuberculosis infection of the bovine host is not well understood; however, it is assumed that crossing the bovine intestinal mucosa is important in order for M. avium subsp. paratuberculosis to establish infection. To examine the ability of M. avium subsp. paratuberculosis to infect bovine epithelial cells in vitro, Madin-Darby bovine kidney (MDBK) epithelial cells were exposed to M. avium subsp. paratuberculosis. It was observed that bacteria can establish infection and replicate within MDBK cells. M. avium subsp. paratuberculosis also has been reported to infect mammary tissue and milk, and we showed that M. avium subsp. paratuberculosis infects bovine mammary epithelial cells (MAC-T cell line). Using polarized MAC-T cell monolayers, it was also determined that M. avium subsp. paratuberculosis crosses apical and basolateral surfaces with approximately the same degree of efficiency. Because M. avium subsp. paratuberculosis can be delivered to the naïve host by milk, it was investigated whether incubation of M. avium subsp. paratuberculosis with milk has an effect on invasion of MDBK cells. M. avium subsp. paratuberculosis exposed to milk entered epithelial cells with greater efficiency than M. avium subsp. paratuberculosis exposed to broth medium or water (P < 0.01). Growth of M. avium subsp. paratuberculosis within MAC-T cells also resulted in augmented ability to subsequently infect bovine MDBK cells (P < 0.001). Microarray analysis of intracellular M. avium subsp. paratuberculosis RNA indicates the increased transcription of genes which might be associated with an invasive phenotype.
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Affiliation(s)
- Dilip Patel
- Department of Food Science, Oregon State University, Corvallis, OR 97331, USA
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29
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Miltner E, Daroogheh K, Mehta PK, Cirillo SLG, Cirillo JD, Bermudez LE. Identification of Mycobacterium avium genes that affect invasion of the intestinal epithelium. Infect Immun 2005; 73:4214-21. [PMID: 15972512 PMCID: PMC1168615 DOI: 10.1128/iai.73.7.4214-4221.2005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Invasion of intestinal mucosa of the host by Mycobacterium avium is a critical step in pathogenesis and likely involves several different bacterial proteins, lipids, glycoproteins, and/or glycolipids. Through the screening of an M. avium genomic library in Mycobacterium smegmatis, we have identified a number of M. avium genes that are associated with increased invasion of mucosal epithelial cells. In order to further investigate these genes, we cloned six of them into a plasmid downstream of a strong mycobacterial promoter (L5 mycobacterial phage promoter), resulting in constitutive expression. Bacteria were then evaluated for increased expression and examined for invasion of HT-29 intestinal epithelial cells. The genes identified encode proteins that are similar to (i) M. tuberculosis coenzyme A carboxylase, (ii) M. tuberculosis membrane proteins of unknown function, (iii) M. tuberculosis FadE20, (iv) a Mycobacterium paratuberculosis surface protein, and (v) M. tuberculosis cyclopropane fatty acyl-phopholipid synthase. The constitutive expression of these genes confers to M. avium the ability to invade HT-29 intestinal epithelial cells with a severalfold increase in efficiency compared to both the wild-type M. avium and M. avium containing the vector alone. Using the murine intestinal ligated loop model, it was observed that the constitutive expression of M. avium proteins has a modest impact on the ability to enter the intestinal mucosa when compared with the wild-type control, suggesting that under in vivo conditions these genes are expressed at higher levels. Evaluation of the expression of these invasion-related genes indicated that under conditions similar to the intestinal lumen environment, the genes identified are upregulated. These data suggest that invasion of the intestinal mucosa is an event that requires the participation of several bacterial factors and the expression of the genes that encode them is less observed under standard laboratory growth conditions.
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Affiliation(s)
- Elizabeth Miltner
- Kuzell Institute for Arthritis & Infectious Diseases, San Francisco, California, USA
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30
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Salas-Vidal E, Meijer AH, Cheng X, Spaink HP. Genomic annotation and expression analysis of the zebrafish Rho small GTPase family during development and bacterial infection. Genomics 2005; 86:25-37. [PMID: 15894457 DOI: 10.1016/j.ygeno.2005.03.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2004] [Revised: 03/23/2005] [Accepted: 03/24/2005] [Indexed: 11/22/2022]
Abstract
The zebrafish genomic sequence database was analyzed for the presence of genes encoding members of the Rho small GTPases. The analysis shows the presence of 32 zebrafish Rho genes representing one or more homologs of the human RHOA, RND3, RHOF, RHOG, RHOH, RHOJ, RHOU, RHOV, CDC42, RAC1, RAC2, RAC3, RND1, RHOBTB1, RHOBTB2, RHOBTB3, and RHOT1 genes. By expression analysis using reverse transcriptase-PCR we show that at least 20 of the predicted zebrafish small GTPase genes are expressed in the adult stage. Interestingly, only 5 of these were found to be expressed at early embryonic stages, including rhoab, rhoad, cdc42a, cdc42c, and rac1a. We observed a strong upregulation of zebrafish rhogb expression after Mycobacterium marinum infection of adult fish. This complete annotation study provides a firm basis for the use of zebrafish as a model for analysis of Rho GTPase function in vertebrate development and the innate immune system.
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MESH Headings
- Amino Acid Sequence
- Animals
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Databases, Nucleic Acid
- Gene Expression Profiling
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Enzymologic
- Genome
- Genome, Human
- Genomics/methods
- Genomics/statistics & numerical data
- Humans
- Molecular Sequence Data
- Multigene Family/genetics
- Mycobacterium Infections, Nontuberculous/genetics
- Mycobacterium Infections, Nontuberculous/microbiology
- Mycobacterium marinum/growth & development
- Phylogeny
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Zebrafish/genetics
- Zebrafish/growth & development
- Zebrafish/microbiology
- Zebrafish Proteins/genetics
- rho GTP-Binding Proteins/genetics
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Affiliation(s)
- Enrique Salas-Vidal
- Institute of Biology, Leiden University, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands.
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31
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Abstract
Environmental mycobacteria are emerging pathogens causing opportunistic infections in humans and animals. The health impacts of human-mycobacterial interactions are complex and likely much broader than currently recognized. Environmental mycobacteria preferentially survive chlorination in municipal water, using it as a vector to infect humans. Widespread chlorination of water has likely selected more resistant environmental mycobacteria species and potentially explains the shift from M. scrofulaceum to M. avium as a cause of cervical lymphadenitis in children. Thus, human activities have affected mycobacterial ecology. While the slow growth and hydrophobicity of environmental mycobacteria appear to be disadvantages, the unique cell wall architecture also grants high biocide and antibiotic resistance, while hydrophobicity facilitates nutrient acquisition, biofilm formation, and spread by aerosolization. The remarkable stress tolerance of environmental mycobacteria is the major reason they are human pathogens. Environmental mycobacteria invade protozoans, exhibiting parasitic and symbiotic relationships. The molecular mechanisms of mycobacterial intracellular pathogenesis in animals likely evolved from similar mechanisms facilitating survival in protozoans. In addition to outright infection, environmental mycobacteria may also play a role in chronic bowl diseases, allergies, immunity to other pulmonary infections, and the efficacy of bacillus Calmette-Guerin vaccination.
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Affiliation(s)
- Todd P Primm
- Department of Biological Sciences and Border Biomedical Research Center, University of Texas at El Paso, El Paso, Texas 79968, USA.
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32
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Reed SM, Bayly WM, Sellon DC. Mechanisms of Infectious Disease. EQUINE INTERNAL MEDICINE 2004. [PMCID: PMC7278211 DOI: 10.1016/b0-72-169777-1/50004-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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33
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Abstract
M avium is a microorganism well adapted to living in the environment and in different hosts. During the past 15 years, a substantial amount of information has been accumulated about the mechanisms used by M avium to cross the host's mucosal barrier, replicate inside cells, circumvent the host's immune response, and persist inside the host. It turns out that M avium is a fascinating pathogen after all. The increasing knowledge about M avium pathogenesis may one day provide means for a more effective prophylaxis as well as for treatment of the infection.
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Affiliation(s)
- Jeffery McGarvey
- Kuzell Institute, California Pacific Medical Center Research Institute, 2200 Webster Street, Suite 305, San Francisco, CA 94115, USA
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34
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Abstract
Immunocompromised patients, including patients with AIDS, solid organ and bone marrow transplant recipients, patients with leukemia and lymphoma, patients with inherited immune deficiencies, and patients on immunosuppressive therapy for a variety of disorders, are at risk for infections-particularly opportunistic infections, which, by definition, do not infect the healthy host. All systems of the body, including the gastrointestinal tract, are susceptible. The esophagus, stomach, small intestine, and large intestine are sites of infection for viruses, bacteria, fungi, and protozoa. Symptoms can range in severity from fevers of unknown etiology to life-threatening hemorrhage and perforation. This review summarizes recent case reports, clinical studies, and reviews pertaining to pathogens that uniquely cause disease, more frequently cause disease, or cause more severe disease in the immunocompromised host than in the immunocompetent host.
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Affiliation(s)
- Lori Fantry
- Institute of Human Virology, University of Maryland Medical School, Baltimore, Maryland 21201, USA.
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Bermudez LE, Sangari FJ, Kolonoski P, Petrofsky M, Goodman J. The efficiency of the translocation of Mycobacterium tuberculosis across a bilayer of epithelial and endothelial cells as a model of the alveolar wall is a consequence of transport within mononuclear phagocytes and invasion of alveolar epithelial cells. Infect Immun 2002; 70:140-6. [PMID: 11748175 PMCID: PMC127600 DOI: 10.1128/iai.70.1.140-146.2002] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The mechanism(s) by which Mycobacterium tuberculosis crosses the alveolar wall to establish infection in the lung is not well known. In an attempt to better understand the mechanism of translocation and create a model to study the different stages of bacterial crossing through the alveolar wall, we established a two-layer transwell system. M. tuberculosis H37Rv was evaluated regarding the ability to cross and disrupt the membrane. M. tuberculosis invaded A549 type II alveolar cells with an efficiency of 2 to 3% of the initial inoculum, although it was not efficient in invading endothelial cells. However, bacteria that invaded A549 cells were subsequently able to be taken up by endothelial cells with an efficiency of 5 to 6% of the inoculum. When incubated with a bicellular transwell monolayer (epithelial and endothelial cells), M. tuberculosis translocated into the lower chamber with efficiency (3 to 4%). M. tuberculosis was also able to efficiently translocate across the bicellular layer when inside monocytes. Infected monocytes crossed the barrier with greater efficiency when A549 alveolar cells were infected with M. tuberculosis than when A549 cells were not infected. We identified two potential mechanisms by which M. tuberculosis gains access to deeper tissues, by translocating across epithelial cells and by traveling into the blood vessels within monocytes.
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Affiliation(s)
- Luiz E Bermudez
- Kuzell Institute for Arthritis & Infectious Diseases, California Pacific Medical Center Research Institute, University of California, San Francisco, California, USA.
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Sangari FJ, Goodman J, Petrofsky M, Kolonoski P, Bermudez LE. Mycobacterium avium invades the intestinal mucosa primarily by interacting with enterocytes. Infect Immun 2001; 69:1515-20. [PMID: 11179321 PMCID: PMC98050 DOI: 10.1128/iai.69.3.1515-1520.2001] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previous studies have demonstrated that Mycobacterium avium can invade intestinal epithelial cells both in vitro and in vivo. When given to mice orally, M. avium preferentially interacts with the intestinal mucosa at the terminal ileum. We evaluated the mechanism(s) of M. avium binding and invasion of the intestinal mucosa using three different systems: (i) electron microscopy following administration of M. avium into an intestinal loop in mice, (ii) quantitative comparison of the bacterial load in Peyer's patch areas of the terminal ileum versus areas that do not contain Peyer's patches, and (iii) investigation of the ability of M. avium to cause disseminated infection following oral administration using B-cell-deficient mice, lacking Peyer's patches, in comparison with C57BL/6 black mice. By all approaches, M. avium was found to invade the intestinal mucosa by interacting primarily with enterocytes and not with M cells.
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Affiliation(s)
- F J Sangari
- Kuzell Institute for Arthritis and Infectious Diseases, California Pacific Medical Center Research Institute, San Francisco, California 94115, USA
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37
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Bermudez LE, Sangari FJ. Cellular and molecular mechanisms of internalization of mycobacteria by host cells. Microbes Infect 2001; 3:37-42. [PMID: 11226852 DOI: 10.1016/s1286-4579(00)01355-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mycobacteria are intracellular pathogens capable of invading mononuclear phagocytes, mucosal epithelial cells (including M cells) and Schwann cells. To enter cells, mycobacteria have been shown to interact with several molecules on macrophage and epithelial cell surfaces. This suggests adaptation to the host environment. In this review we address the strategies used by pathogenic mycobacteria to gain access to the intracellular environment.
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Affiliation(s)
- L E Bermudez
- Kuzell Institute for Arthritis & Infectious Diseases, California Pacific Medical Center Research Institute, San Francisco, USA.
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