scholarly journals Effect of Deletion or Overexpression of the 19-Kilodalton Lipoprotein Rv3763 on the Innate Response to Mycobacterium tuberculosis

2005 ◽  
Vol 73 (10) ◽  
pp. 6831-6837 ◽  
Author(s):  
Graham R. Stewart ◽  
Katalin A. Wilkinson ◽  
Sandra M. Newton ◽  
Susan M. Sullivan ◽  
Olivier Neyrolles ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Human Monocyte ◽  
Surface Expression ◽  
Innate Immune ◽  
Innate Response ◽  
Necrosis Factor Alpha ◽  
Histocompatibility Complex ◽  
Factor Alpha ◽  
Multicopy Vector ◽  
Necrosis Factor

ABSTRACT The 19-kDa lipoprotein of Mycobacterium tuberculosis is an important target of the innate immune response. To investigate the immune biology of this antigen in the context of the whole bacillus, we derived a recombinant M. tuberculosis H37Rv that lacked the 19-kDa-lipoprotein gene (Δ19) and complemented this strain by reintroduction of the 19-kDa-lipoprotein gene on a multicopy vector to produce Δ19::pSMT181. The Δ19 strain multiplied less well than Δ19::pSMT181 in human monocyte-derived macrophages (MDM) (P = 0.039). Surface expression of major histocompatibility complex class II molecules was reduced in phagocytes infected with M. tuberculosis; this effect was not seen in cells infected with Δ19. Δ19 induced lower interleukin 1β (IL-1β) secretion from monocytes and MDM. Overexpression of the 19-kDa protein increased IL-1β, IL-12p40, and tumor necrosis factor alpha secretion irrespective of phagocyte maturity. These data support reports that the 19-kDa lipoprotein has pleiotropic effects on the interaction of M. tuberculosis with phagocytes. However, this analysis indicates that in the context of the whole bacillus, the 19-kDa lipoprotein is only one of a number of molecules that mediate the innate response to M. tuberculosis.

scholarly journals Human Immunodeficiency Virus Infection Alters Tumor Necrosis Factor Alpha Production via Toll-Like Receptor-Dependent Pathways in Alveolar Macrophages and U1 Cells

2008 ◽  
Vol 82 (16) ◽  
pp. 7790-7798 ◽  
Author(s):  
Marlynne Q. Nicol ◽  
Jean-Marie Mathys ◽  
Albertina Pereira ◽  
Kevin Ollington ◽  
Michael H. Ieong ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Innate Immune ◽  
Hiv Positive ◽  
Toll Like Receptor ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Immunodeficiency Virus ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACT Human immunodeficiency virus (HIV)-positive persons are predisposed to pulmonary infections, even after receiving effective highly active antiretroviral therapy. The reasons for this are unclear but may involve changes in innate immune function. HIV type 1 infection of macrophages impairs effector functions, including cytokine production. We observed decreased constitutive tumor necrosis factor alpha (TNF-α) concentrations and increased soluble tumor necrosis factor receptor type II (sTNFRII) in bronchoalveolar lavage fluid samples from HIV-positive subjects compared to healthy controls. Moreover, net proinflammatory TNF-α activity, as measured by the TNF-α/sTNFRII ratio, decreased as HIV-related disease progressed, as manifested by decreasing CD4 cell count and increasing HIV RNA (viral load). Since TNF-α is an important component of the innate immune system and is produced upon activation of Toll-like receptor (TLR) pathways, we hypothesized that the mechanism associated with deficient TNF-α production in the lung involved altered TLR expression or a deficit in the TLR signaling cascade. We found decreased Toll-like receptor 1 (TLR1) and TLR4 surface expression in HIV-infected U1 monocytic cells compared to the uninfected parental U937 cell line and decreased TLR message in alveolar macrophages (AMs) from HIV-positive subjects. In addition, stimulation with TLR1/2 ligand (Pam3Cys) or TLR4 ligand (lipopolysaccharide) resulted in decreased intracellular phosphorylated extracellular signal-regulated kinase and subsequent decreased transcription and expression of TNF-α in U1 cells compared to U937 cells. AMs from HIV-positive subjects also showed decreased TNF-α production in response to these TLR2 and TLR4 ligands. We postulate that HIV infection alters expression of TLRs with subsequent changes in mitogen-activated protein kinase signaling and cytokine production that ultimately leads to deficiencies of innate immune responses that predispose HIV-positive subjects to infection.

scholarly journals HLA-B*35-Restricted CD8+-T-Cell Epitope in Mycobacterium tuberculosis Rv2903c

2002 ◽  
Vol 70 (2) ◽  
pp. 981-984 ◽  
Author(s):  
Michèl R. Klein ◽  
Abdulrahman S. Hammond ◽  
Steve M. Smith ◽  
Assan Jaye ◽  
Pauline T. Lukey ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cell Epitope ◽  
T Cell Epitope ◽  
T Cell Epitopes ◽  
Necrosis Factor Alpha ◽  
Factor Alpha ◽  
Mycobacterial Antigens ◽  
Necrosis Factor

ABSTRACT Few human CD8+ T-cell epitopes in mycobacterial antigens have been described to date. Here we have identified a novel HLA-B*35-restricted CD8+ T-cell epitope in Mycobacterium tuberculosis Rv2903c based on a reverse immunogenetics approach. Peptide-specific CD8 T cells were able to kill M. tuberculosis-infected macrophages and produce gamma interferon and tumor necrosis factor alpha.

scholarly journals Toll-Like Receptor 9 Is Required for Full Host Resistance toMycobacteriumaviumInfection but Plays No Role in Induction of Th1 Responses

2011 ◽  
Vol 79 (4) ◽  
pp. 1638-1646 ◽  
Author(s):  
Natália B. Carvalho ◽  
Fernanda S. Oliveira ◽  
Fernanda V. Durães ◽  
Leonardo A. de Almeida ◽  
Manuela Flórido ◽  
...  
Keyword(s):  
Interleukin 12 ◽  
Toll Like Receptor ◽  
Necrosis Factor Alpha ◽  
Histocompatibility Complex ◽  
Tnf Α ◽  
Factor Alpha ◽  
Ifn Γ ◽  
Myd88 Signaling ◽  
Necrosis Factor

ABSTRACTTo investigate the role of Toll-like receptor 9 (TLR9) in innate immunity toMycobacteriumavium, TLR9, TLR2, and MyD88 knockout (KO) mice were infected with this bacterium. Bacterial burdens were higher in the spleens, livers, and lungs of infected TLR9 KO mice than in those of C57BL/6 mice, indicating that TLR9 is required for efficient control ofM.aviuminfection. However, TLR9 KO or TLR2 KO spleen cells displayed normalM.avium-induced tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ) responses. This finding was confirmed by determining the number of splenic CD4+T cells producing IFN-γ by flow cytometry. Furthermore, TLR2 and MyD88, but not TLR9, played a major role in interleukin-12 and TNF-α production byM.avium-infected macrophages and dendritic cells (DCs). We also found that major histocompatibility complex class II molecule expression on DCs is regulated by TLR2 and MyD88 signaling but not by TLR9. Finally, lack of TLR9, TLR2, or MyD88 reduced the numbers of macrophages, epithelioid cells, and lymphocytes inM.avium-induced granulomas but only MyD88 deficiency affected the number of liver granulomas. In summary, our data demonstrated that the involvement of TLR9 in the control ofM.aviuminfection is not related to the induction of Th1 responses.

scholarly journals Thalidomide selectively inhibits tumor necrosis factor alpha production by stimulated human monocytes.

1991 ◽  
Vol 173 (3) ◽  
pp. 699-703 ◽  
Author(s):  
E P Sampaio ◽  
E N Sarno ◽  
R Galilly ◽  
Z A Cohn ◽  
G Kaplan
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Interleukin 1 ◽  
Human Monocyte ◽  
Tnf Alpha ◽  
Necrosis Factor Alpha ◽  
Factor Alpha ◽  
Necrosis Factor

Thalidomide selectively inhibits the production of human monocyte tumor necrosis factor alpha (TNF-alpha) when these cells are triggered with lipopolysaccharide and other agonists in culture. 40% inhibition occurs at the clinically achievable dose of the drug of 1 micrograms/ml. In contrast, the amount of total protein and individual proteins labeled with [35S]methionine and expressed on SDS-PAGE are not influenced. The amounts of interleukin 1 beta (IL-1 beta), IL-6, and granulocyte/macrophage colony-stimulating factor produced by monocytes remain unaltered. The selectivity of this drug may be useful in determining the role of TNF-alpha in vivo and modulating its toxic effects in a clinical setting.

scholarly journals Poxvirus Host Range Protein CP77 Contains an F-Box-Like Domain That Is Necessary To Suppress NF-κB Activation by Tumor Necrosis Factor Alpha but Is Independent of Its Host Range Function

2009 ◽  
Vol 83 (9) ◽  
pp. 4140-4152 ◽  
Author(s):  
Shu-Jung Chang ◽  
Jye-Chian Hsiao ◽  
Stephanie Sonnberg ◽  
Cheng-Ting Chiang ◽  
Min-Hsiang Yang ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Host Range ◽  
Tumor Necrosis ◽  
Innate Immune ◽  
Necrosis Factor Alpha ◽  
Scf Complex ◽  
Range Function ◽  
Tnf Α ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACT Tumor necrosis factor alpha (TNF-α) activates the nuclear factor κB (NF-κB) signaling pathway that regulates expression of many cellular factors playing important roles in innate immune responses and inflammation in infected hosts. Poxviruses employ many strategies to inhibit NF-κB activation in cells. In this report, we describe a poxvirus host range protein, CP77, which blocked NF-κB activation by TNF-α. Immunofluorescence analyses revealed that nuclear translocation of NF-κB subunit p65 protein in TNF-α-treated HeLa cells was blocked by CP77. CP77 did so without blocking IκBα phosphorylation, suggesting that upstream kinase activation was not affected by CP77. Using GST pull-down, we showed that CP77 bound to the NF-κB subunit p65 through the N-terminal six-ankyrin-repeat region in vitro. CP77 also bound to Cullin-1 and Skp1 of the SCF complex through a C-terminal 13-amino-acid F-box-like sequence. Both regions of CP77 are required to block NF-κB activation. We thus propose a model in which poxvirus CP77 suppresses NF-κB activation by two interactions: the C-terminal F-box of CP77 binding to the SCF complex and the N-terminal six ankyrins binding to the NF-κB subunit p65. In this way, CP77 attenuates innate immune response signaling in cells. Finally, we expressed CP77 or a CP77 F-box deletion protein from a vaccinia virus host range mutant (VV-hr-GFP) and showed that either protein was able to rescue the host range defect, illustrating that the F-box region, which is important for NF-κB modulation and binding to SCF complex, is not required for CP77's host range function. Consistently, knocking down the protein level of NF-κB did not relieve the growth restriction of VV-hr-GFP in HeLa cells.

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