Abstract:
:Previously, we reported that mutants of Legionella pneumophila lacking a type II secretion (T2S) system elicit higher levels of cytokines (e.g., interleukin-6 [IL-6]) following infection of U937 cells, a human macrophage-like cell line. We now show that this effect of T2S is also manifest upon infection of human THP-1 macrophages and peripheral blood monocytes but does not occur during infection of murine macrophages. Supporting the hypothesis that T2S acts to dampen the triggering of an innate immune response, we observed that the mitogen-activated protein kinase (MAPK) and nuclear transcription factor kappa B (NF-κB) pathways are more highly stimulated upon infection with the T2S mutant than upon infection with the wild type. By using short hairpin RNA to deplete proteins involved in specific pathogen-associated molecular pattern (PAMP) recognition pathways, we determined that the dampening effect of the T2S system was not dependent on nucleotide binding oligomerization domain (NOD)-like receptors (NLRs), retinoic acid-inducible protein I (RIG-I)-like receptors (RLRs), double-stranded RNA (dsRNA)-dependent protein kinase receptor (PKR), or TIR domain-containing adaptor inducing interferon beta (TRIF) signaling or an apoptosis-associated speck-like protein containing a CARD (ASC)- or caspase-4-dependent inflammasome. However, the dampening effect of T2S on IL-6 production was significantly reduced upon gene knockdown of myeloid differentiation primary response 88 (MyD88), TANK binding kinase 1 (TBK1), or Toll-like receptor 2 (TLR2). These data indicate that the L. pneumophila T2S system dampens the signaling of the TLR2 pathway in infected human macrophages. We also document the importance of PKR, TRIF, and TBK1 in cytokine secretion during L. pneumophila infection of macrophages.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Mallama CA,McCoy-Simandle K,Cianciotto NPdoi
10.1128/IAI.00897-16subject
Has Abstractpub_date
2017-03-23 00:00:00issue
4eissn
0019-9567issn
1098-5522pii
IAI.00897-16journal_volume
85pub_type
杂志文章abstract::The importance of CD4+ cells and gamma interferon (IFN-gamma) in the resolution of established Cryptosporidium parvum infection was investigated with a murine model of cryptosporidiosis in severe combined immunodeficient (SCID) mice. C. parvum-infected SCID mice were reconstituted with spleen cells from immunocompeten...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.9.3928-3932.1993
更新日期:1993-09-01 00:00:00
abstract::Understanding the extent to which genetic factors influence the immune response is important in the development of subunit vaccines. Associations with HLA gene polymorphisms appear insufficient to explain the range of variation in immune responses to vaccines and to infections by major pathogens. In this study of Gamb...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.3.872-876.1997
更新日期:1997-03-01 00:00:00
abstract::A progressive increase in infections with multiresistant Enterococcus faecium has been reported, especially in cancer patients and neutropenic patients. Despite its increasing importance as a nosocomial pathogen, knowledge of the pathogenesis of E. faecium infections is highly limited. In this study, we investigated t...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00863-08
更新日期:2009-01-01 00:00:00
abstract::Pseudomonas aeruginosa elastase rapidly inactivates alpha 1-proteinase inhibitor by splitting its Pro-357-Met-358 peptide bond. The present study was aimed at testing whether this reaction takes place in the presence of leukocyte elastase. To this end was added alpha 1-proteinase inhibitor to a mixture of the two elas...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.12.3793-3797.1989
更新日期:1989-12-01 00:00:00
abstract::Using fluorescent antibody techniques (FA) and light microscopy (LM) and electron microscopy (EM), this paper describes the morphological features of the ileum in the DK1 mouse orally challenged with adenovirus K87. At the peak of infection, virus is easily identified by FA in the epithelium of the villi and crypts of...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.13.2.569-580.1976
更新日期:1976-02-01 00:00:00
abstract::Tox-+ staphylococcal strains, as opposed to Tox-minus strains, produce epidermal exfoliation within 18 h after direct subcutaneous or intraperitoneal injection into newborn mice. The extracellular product responsible for exfoliation is termed exfoliative toxin (ET). When culture supernatant fluid from the plasmid-cure...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.12.1.193-197.1975
更新日期:1975-07-01 00:00:00
abstract::IL12RB1 is a human gene that is important for resistance to Mycobacterium tuberculosis infection. IL12RB1 is expressed by multiple leukocyte lineages, and encodes a type I transmembrane protein (IL12Rβ1) that associates with IL12p40 and promotes the development of host-protective T(H)1 cells. Recently, we observed tha...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01230-13
更新日期:2015-02-01 00:00:00
abstract::Interleukin-10 (IL-10) is associated with inhibition of cell-mediated immunity and downregulation of the expression of costimulatory molecules required for T-cell activation. When IL-10-deficient (IL-10KO) mice are infected with Toxoplasma gondii, they succumb to a T-cell-mediated shock-like reaction characterized by ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.5.2837-2844.2000
更新日期:2000-05-01 00:00:00
abstract::Four classes of mutants of type III group B streptococcus were isolated by serial subculture of the wild-type strain in the presence of type III-specific rabbit antiserum. Class I mutants no longer synthesized sialic acid but still elaborated the core antigen. Class II mutants maintained the ability to synthesize sial...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.42.1.141-151.1983
更新日期:1983-10-01 00:00:00
abstract::Antibiotics suppressed development of aster yellows (AY) disease symptoms in plants of china aster [Callistephus chinensis (L.) Nees.] and annual chrysanthemum (Chrysanthemum carinatum, Schousb.). When inoculated chrysanthemum plants were treated by any of several techniques with tetracycline antibiotics or chloramphe...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.2.2.201-208.1970
更新日期:1970-08-01 00:00:00
abstract::Immunity to reinfection in the genital tract of female guinea pigs with the agent of guinea pig inclusion conjunctivitis was found to be dependent upon an intact humoral immune response. Cell-mediated immunity in the absence of humoral immunity had no apparent role in resistance to challenge infection. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.39.1.463-465.1983
更新日期:1983-01-01 00:00:00
abstract::The in vivo role of endogenous interleukin 12 (IL-12) in modulating intrapulmonary growth of Legionella pneumophila was assessed by using a murine model of replicative L. pneumophila lung infection. Intratracheal inoculation of A/J mice with virulent bacteria (10(6) L. pneumophila cells per mouse) resulted in inductio...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.66.1.65-69.1998
更新日期:1998-01-01 00:00:00
abstract::The effect of iron concentration during growth on the physicochemical surface properties of the colonial variants of Neisseria gonorrhoeae has been assessed by aqueous two-phase partitioning in a dextran-polyethyleneglycol system containing positively charged trimethylamino-polyethyleneglycol or hydrophobic polyethyle...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.26.2.402-407.1979
更新日期:1979-11-01 00:00:00
abstract::The 34-kilodalton (kDa) antigen of Treponema pallidum subsp. pallidum (T. pallidum) is a pathogen-specific integral membrane protein. DNA sequence analysis of the cloned gene revealed an open reading frame encoding a primary product of 204 residues with a molecular mass of 22,087 daltons. Sequences that correspond to ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.11.3314-3323.1989
更新日期:1989-11-01 00:00:00
abstract::We identified a gene (atlA) encoding autolytic activity from Streptococcus mutans Xc. The AtlA protein predicted to be encoded by atlA is composed of 979 amino acids with a molecular weight of 107,279 and has a conserved beta-1,4-N-acetylmuramidase (lysozyme) domain in the C-terminal portion. Sodium dodecyl sulfate ex...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.6.3512-3520.2005
更新日期:2005-06-01 00:00:00
abstract::It was shown in this work that the infectivity of metacyclic forms of Trypanosoma cruzi was affected upon interaction with the monoclonal antibody (10D8), which reacts with a carbohydrate epitope of the 35- and 50-kilodalton (kDa) surface glycoconjugates. The invasion of Vero cells by metacyclic forms of strains Tulah...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.6.1663-1667.1989
更新日期:1989-06-01 00:00:00
abstract::Gamma interferon (IFN-gamma)-activated macrophages use an alternative processing mechanism to present Salmonella antigens to CD8(+) T lymphocytes. This pathway involves processing of antigen in a vacuolar compartment followed by secretion and loading of antigenic peptides to major histocompatibility complex class I (M...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.7.3937-3944.2005
更新日期:2005-07-01 00:00:00
abstract::Effector mechanisms resulting from alternative complement pathway (ACP) activation cannot act efficiently against Yersinia enterocolitica serotype O3, as indicated by poor C3 to C9 consumption and by survival in EGTA (ethyleneglycoldiaminetetraacetic acid) Mg-serum. These results were not influenced by the lack or pre...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.7.1984-1989.1989
更新日期:1989-07-01 00:00:00
abstract::Cryptosporidial infections in severe combined immune deficient (SCID) mice produce a chronic disease state which in the later stages leads to extraintestinal involvement and hepatic dysfunction. To further characterize the infection dynamics in this model and monitor the changes in the hepatic system, a dose titration...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.5.1691-1695.1994
更新日期:1994-05-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.15.1.91-103.1977
更新日期:1977-01-01 00:00:00
abstract::The outer membrane protein OmpU of Vibrio cholerae O1 strain 86B3 was characterized with reference to colonization of the intestine by the organism. The purified OmpU exhibited a pI of 3.6. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis, it migrated to 38, 32, and 110 kDa when the sample was heated at ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.66.10.4726-4728.1998
更新日期:1998-10-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.1.400-404.2001
更新日期:2001-01-01 00:00:00
abstract::The pattern of invasion of human hair in vitro by the dermatophyte Microsporum gypseum was studied by transmission and scanning electron microscopy. Mycelia that invaded the hair cortex through the edge of cuticles showed a flattened "frond" growth in contrast to the filamentous form seen on ordinary laboratory media....
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.38.2.706-715.1982
更新日期:1982-11-01 00:00:00
abstract::The role of CD19(+) CD5(+) and CD19(+) CD5(-) B cell subpopulations in the antibody response to pneumococcal capsular polysaccharides (caps-PSs) is controversial. In the present study, we evaluated the role of human CD19(+) CD5(+) and CD19(+) CD5(-) cell populations in the serotype-specific antibody response to caps-P...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00068-15
更新日期:2015-07-01 00:00:00
abstract::Female guinea pigs were immunized with viable or UV light-inactivated chlamydiae (agent of guinea pig inclusion conjunctivitis), belonging to the species Chlamydia psittaci, by intravenous, subcutaneous, oral, or ocular routes. All animals were then inoculated vaginally with viable chlamydiae to determine the extent o...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.58.8.2599-2605.1990
更新日期:1990-08-01 00:00:00
abstract::Staphylococcus aureus nitric oxide synthase (saNOS) is a major contributor to virulence, stress resistance, and physiology, yet the specific mechanism(s) by which saNOS intersects with other known regulatory circuits is largely unknown. The SrrAB two-component system, which modulates gene expression in response to the...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00570-18
更新日期:2019-01-24 00:00:00
abstract::Vaccination with native full-length merozoite surface protein 1 (MSP1) or with recombinant C-terminal peptides protects mice against lethal challenge with virulent malaria parasites. To determine whether other regions of MSP1 can also induce protection, Plasmodium yoelii MSP1 was divided into four separate regions. Ea...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.8.3032-3036.1997
更新日期:1997-08-01 00:00:00
abstract::The influence of D-alanine and carbohydrate substitution of lipoteichoic acids (LTAs) on the binding of antibody directed to the polyglycerol phosphate (PGP) portion was found to be at least partially dependent upon the mode of presentation of the antigen. There were greater differences in binding of anti-PGP immunogl...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.41.2.549-555.1983
更新日期:1983-08-01 00:00:00
abstract::Two proteins, HifD and HifE, have been identified as structural components of Haemophilus influenzae pili. Both are localized at the pilus tip, and HifE appears to mediate pilus adherence to host cells. In this study we examined the immunologic and structural diversity of these pilus subunits among type b H. influenza...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.66.10.4788-4796.1998
更新日期:1998-10-01 00:00:00
abstract::Intestinal epithelial activation of nuclear factor kappa B (NF-κB) exerts both detrimental and beneficial functions in response to various luminal insults, including ones associated with mucosa-associated pathogens. Gastrointestinal infection with enteropathogenic Escherichia coli (EPEC) causes severe injuries in epit...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00162-13
更新日期:2013-06-01 00:00:00