scholarly journals Burkholderia pseudomallei-Induced Expression of Suppressor of Cytokine Signaling 3 and Cytokine-Inducible Src Homology 2-Containing Protein in Mouse Macrophages: a Possible Mechanism for Suppression of the Response to Gamma Interferon Stimulation

2005 ◽  
Vol 73 (11) ◽  
pp. 7332-7339 ◽  
Author(s):  
P. Ekchariyawat ◽  
S. Pudla ◽  
K. Limposuwan ◽  
S. Arjcharoen ◽  
S. Sirisinha ◽  
...  
Keyword(s):  
Burkholderia Pseudomallei ◽  
Gamma Interferon ◽  
Inos Expression ◽  
Cytokine Signaling ◽  
Phagocytic Cells ◽  
Suppressor Of Cytokine Signaling ◽  
Src Homology 2 ◽  
Src Homology ◽  
Ifn Γ ◽  
Macrophage Killing

ABSTRACT Burkholderia pseudomallei, the causative agent of melioidosis, is a facultative intracellular gram-negative bacterium that is able to survive and multiply in macrophages. Previously, we reported that B. pseudomallei was able to escape macrophage killing by interfering with the expression of inducible nitric oxide synthase (iNOS). In the present study, we extended this finding and demonstrated that B. pseudomallei was able to activate the expression of suppressor of cytokine signaling 3 (SOCS3) and cytokine-inducible Src homology 2-containing protein (CIS) but not SOCS1 in a mouse macrophage cell line (RAW 264.7). The expression of SOCS3 and CIS in B. pseudomallei-infected macrophages directly correlated with a decreased gamma interferon (IFN-γ) signaling response, as indicated by a reduction in Y701-STAT-1 phosphorylation (pY701-STAT-1). Moreover, a reduction in the expression of IFN-γ-induced proteins, such as interferon regulatory factor 1 (IRF-1), was observed in B. pseudomallei-infected macrophages that were treated with IFN-γ. Since pY701-STAT-1 and IRF-1 are essential transcription factors for regulating iNOS expression, the failure to activate these factors could also result in depression of iNOS expression and a loss of macrophage killing capacity. Taken together, the data indicate that the activation of SOCS3 and CIS expression in B. pseudomallei-infected macrophages interfered with IFN-γ signaling, thus allowing the bacteria to escape killing by these phagocytic cells.

scholarly journals Suppressor of cytokine signaling-1 mimetic peptides attenuate lymphocyte activation in the MRL/lpr mouse autoimmune model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jatin Sharma ◽  
Teresa D. Collins ◽  
Tracoyia Roach ◽  
Shiwangi Mishra ◽  
Brandon K. Lam ◽  
...  
Keyword(s):  
Intraperitoneal Administration ◽  
Lymphocyte Activation ◽  
Signal Propagation ◽  
Skin Lesions ◽  
Effector Memory ◽  
Cytokine Signaling ◽  
Suppressor Of Cytokine Signaling ◽  
Autoantibody Production ◽  
Ifn Γ

AbstractAutoimmune diseases are driven largely by a pathogenic cytokine milieu produced by aberrantly activated lymphocytes. Many cytokines, including interferon gamma (IFN-γ), utilize the JAK/STAT pathway for signal propagation. Suppressor of Cytokine Signaling-1 (SOCS1) is an inducible, intracellular protein that regulates IFN-γ signaling by dampening JAK/STAT signaling. Using Fas deficient, MRL/MpJ-Faslpr/J (MRL/lpr) mice, which develop lupus-like disease spontaneously, we tested the hypothesis that a peptide mimic of the SOCS1 kinase inhibitory region (SOCS1-KIR) would inhibit lymphocyte activation and modulate lupus-associated pathologies. Consistent with in vitro studies, SOCS1-KIR intraperitoneal administration reduced the frequency, activation, and cytokine production of memory CD8+ and CD4+ T lymphocytes within the peripheral blood, spleen, and lymph nodes. In addition, SOCS1-KIR administration reduced lymphadenopathy, severity of skin lesions, autoantibody production, and modestly reduced kidney pathology. On a cellular level, peritoneal SOCS1-KIR administration enhanced Foxp3 expression in total splenic and follicular regulatory T cells, reduced the effector memory/naïve T lymphocyte ratio for both CD4+ and CD8+ cells, and reduced the frequency of GL7+ germinal center enriched B cells. Together, these data show that SOCS1-KIR treatment reduced auto-reactive lymphocyte effector functions and suggest that therapeutic targeting of the SOCS1 pathway through peptide administration may have efficacy in mitigating autoimmune pathologies.

scholarly journals MicroRNA 155 Contributes to Host Immunity against Leishmania donovani but Is Not Essential for Resolution of Infection

2019 ◽  
Vol 87 (8) ◽  
Author(s):  
Sanjay Varikuti ◽  
Gayathri Natarajan ◽  
Greta Volpedo ◽  
Bhawana Singh ◽  
Omar Hamza ◽  
...  
Keyword(s):  
Leishmania Donovani ◽  
Interleukin 4 ◽  
Cytokine Signaling ◽  
T Helper 1 ◽  
Content Type ◽  
Inflammatory Monocytes ◽  
Organ Specific ◽  
Src Homology ◽  
Ifn Γ ◽  
Src Homology 2 Domain

ABSTRACT CD4+ T helper 1 (Th1) cells producing interferon gamma (IFN-γ) are critical for the resolution of visceral leishmaniasis (VL). MicroRNA 155 (miR155) promotes CD4+ Th1 responses and IFN-γ production by targeting suppressor of cytokine signaling-1 (SOCS1) and Src homology-2 domain-containing inositol 5-phosphatase 1 (SHIP-1) and therefore could play a role in the resolution of VL. To determine the role of miR155 in VL, we monitored the course of Leishmania donovani infection in miR155 knockout (miR155KO) and wild-type (WT) C57BL/6 mice. miR155KO mice displayed significantly higher liver and spleen parasite loads than WT controls and showed impaired hepatic granuloma formation. However, parasite growth eventually declined in miR155KO mice, suggesting the induction of a compensatory miR155-independent antileishmanial pathway. Leishmania antigen-stimulated splenocytes from miR155KO mice produced significantly lower levels of Th1-associated IFN-γ than controls. Interestingly, at later time points, levels of Th2-associated interleukin-4 (IL-4) and IL-10 were also lower in miR155KO splenocyte supernatants than in WT mice. On the other hand, miR155KO mice displayed significantly higher levels of IFN-γ, iNOS, and TNF-α gene transcripts in their livers than WT mice, indicating that distinct organ-specific antiparasitic mechanisms were involved in control of L. donovani infection in miR155KO mice. Throughout the course of infection, organs of miR155KO mice showed significantly more PDL1-expressing Ly6Chi inflammatory monocytes than WT mice. Conversely, blockade of Ly6Chi inflammatory monocyte recruitment in miR155KO mice significantly reduced parasitic loads, indicating that these cells contributed to disease susceptibility. In conclusion, we found that miR155 contributes to the control of L. donovani but is not essential for infection resolution.

scholarly journals Helicobacter pyloriInfection Activates Src Homology-2 Domain–Containing Phosphatase 2 To Suppress IFN-γ Signaling

2014 ◽  
Vol 193 (8) ◽  
pp. 4149-4158 ◽  
Author(s):  
Yu-Chih Wang ◽  
Chia-Ling Chen ◽  
Bor-Shyang Sheu ◽  
Yao-Jong Yang ◽  
Po-Chun Tseng ◽  
...  
Keyword(s):  
Src Homology 2 ◽  
Src Homology ◽  
Ifn Γ ◽  
Src Homology 2 Domain

scholarly journals Suppressor of Cytokine Signaling-1 Has IFN-γ-Independent Actions in T Cell Homeostasis

2003 ◽  
Vol 170 (2) ◽  
pp. 878-886 ◽  
Author(s):  
Ann L. Cornish ◽  
Gayle M. Davey ◽  
Donald Metcalf ◽  
Jared F. Purton ◽  
Jason E. Corbin ◽  
...  
Keyword(s):  
T Cell ◽  
Cytokine Signaling ◽  
T Cell Homeostasis ◽  
Suppressor Of Cytokine Signaling ◽  
Cell Homeostasis ◽  
Ifn Γ

scholarly journals Cytokine-Induced Src Homology 2 Protein (Cis) Promotes T Cell Receptor–Mediated Proliferation and Prolongs Survival of Activated T Cells

2000 ◽  
Vol 191 (6) ◽  
pp. 985-994 ◽  
Author(s):  
Suling Li ◽  
Shangwu Chen ◽  
Xiufeng Xu ◽  
Anette Sundstedt ◽  
Kajsa M. Paulsson ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Cell Receptor ◽  
Cytokine Signaling ◽  
Src Homology 2 ◽  
Src Homology

Members of the suppressor of cytokine signaling (SOCS) family were discovered as negative regulators of cytokine signaling by inhibition of the Janus kinase–signal transducer and activator of transcription (Jak-STAT) pathway. Among them, cytokine-induced Src homology 2 (SH2) protein (CIS) was found to inhibit the interleukin 3– and erythropietin-mediated STAT5 signaling pathway. However, involvement of SOCS proteins in other signaling pathways is still unknown. This study shows that the expression of CIS is selectively induced in T cells after T cell receptor (TCR) stimulation. In transgenic mice, with selective expression of CIS in CD4 T cells, elevated CIS strongly promotes TCR-mediated proliferation and cytokine production in vitro, and superantigen-induced T cell activation in vivo. Forced expression of CIS also prolongs survival of CD4 T cells after TCR activation. Molecular events immediately downstream from the TCR are not changed in CIS-expressing CD4 T cells, but activation of mitogen-activated protein (MAP) kinase pathways by TCR stimulation is significantly enhanced. Together with the increased MAP kinase activation, a direct interaction of CIS and protein kinase Cθ was also demonstrated. These results suggest that CIS is one of the important regulators of TCR-mediated T cell activation. The functions of CIS, enhancing TCR signaling and inhibiting cytokine signaling, may be important in the regulation of immune response and homeostasis.

scholarly journals Obligatory Role of Gamma Interferon for Host Survival in a Murine Model of Infection with Burkholderia pseudomallei

1999 ◽  
Vol 67 (7) ◽  
pp. 3593-3600 ◽  
Author(s):  
P. Santanirand ◽  
V. S. Harley ◽  
D. A. B. Dance ◽  
B. S. Drasar ◽  
G. J. Bancroft
Keyword(s):  
Murine Model ◽  
Chronic Infection ◽  
Burkholderia Pseudomallei ◽  
Lethal Dose ◽  
Gamma Interferon ◽  
Interleukin 12 ◽  
Protective Mechanism ◽  
Human Pathology ◽  
Ifn Γ

ABSTRACT Burkholderia pseudomallei, the causative agent of melioidosis, is a gram-negative bacterium capable of causing either acute lethal sepsis or chronic but eventually fatal disease in infected individuals. However, despite the clinical importance of this infection in areas where it is endemic, there is essentially no information on the mechanisms of protective immunity to the bacterium. We describe here a murine model of either acute or chronic infection with B. pseudomallei in Taylor Outbred (TO) mice which mimics many features of the human pathology. Intraperitoneal infection of TO mice at doses of >106 CFU resulted in acute septic shock and death within 2 days. In contrast, at lower doses mice were able to clear the inoculum from the liver and spleen over a 3- to 4-week period, but persistence of the organism at other sites resulted in a chronic infection of between 2 and 16 months duration which was eventually lethal in all of the animals tested. Resistance to acute infection with B. pseudomallei was absolutely dependent upon the production of gamma interferon (IFN-γ) in vivo. Administration of neutralizing monoclonal antibody against IFN-γ lowered the 50% lethal dose from >5 × 105 to ca. 2 CFU and was associated with 8,500- and 4,400-fold increases in the bacterial burdens in the liver and spleen, respectively, together with extensive destruction of lymphoid architecture in the latter organ within 48 h. Neutralization of either tumor necrosis factor alpha or interleukin-12 but not granulocyte-macrophage colony-stimulating factor, also increased susceptibility to infection in vivo. Together, these results provide the first evidence of a host protective mechanism against B. pseudomallei. The rapid production of IFN-γ within the first day of infection determines whether the infection proceeds to an acute lethal outcome or becomes chronic.

scholarly journals Discovery of an exosite on the SOCS2-SH2 domain that enhances SH2 binding to phosphorylated ligands

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Edmond M. Linossi ◽  
Kunlun Li ◽  
Gianluca Veggiani ◽  
Cyrus Tan ◽  
Farhad Dehkhoda ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Sh2 Domain ◽  
Janus Kinase ◽  
Negative Regulator ◽  
Cytokine Signaling ◽  
Signal Transducers ◽  
Src Homology 2 ◽  
Src Homology ◽  
Phosphorylated Peptide ◽  
Α Helix

AbstractSuppressor of cytokine signaling (SOCS)2 protein is a key negative regulator of the growth hormone (GH) and Janus kinase (JAK)-Signal Transducers and Activators of Transcription (STAT) signaling cascade. The central SOCS2-Src homology 2 (SH2) domain is characteristic of the SOCS family proteins and is an important module that facilitates recognition of targets bearing phosphorylated tyrosine (pTyr) residues. Here we identify an exosite on the SOCS2-SH2 domain which, when bound to a non-phosphorylated peptide (F3), enhances SH2 affinity for canonical phosphorylated ligands. Solution of the SOCS2/F3 crystal structure reveals F3 as an α-helix which binds on the opposite side of the SH2 domain to the phosphopeptide binding site. F3:exosite binding appears to stabilise the SOCS2-SH2 domain, resulting in slower dissociation of phosphorylated ligands and consequently, enhances binding affinity. This biophysical enhancement of SH2:pTyr binding affinity translates to increase SOCS2 inhibition of GH signaling.

Sign in / Sign up

Export Citation Format

Share Document