scholarly journals Hydrolysis of Interleukin-12 by Porphyromonas gingivalis Major Cysteine Proteinases May Affect Local Gamma Interferon Accumulation and the Th1 or Th2 T-Cell Phenotype in Periodontitis

2001 ◽  
Vol 69 (9) ◽  
pp. 5650-5660 ◽  
Author(s):  
Peter L. W. Yun ◽  
Arthur A. Decarlo ◽  
Charles Collyer ◽  
Neil Hunter
Keyword(s):  
T Cells ◽  
Porphyromonas Gingivalis ◽  
Disease Process ◽  
Gamma Interferon ◽  
Interleukin 12 ◽  
Cell Phenotype ◽  
Cysteine Proteinases ◽  
Cytokine Balance ◽  
Ifn Γ

ABSTRACT Porphyromonas gingivalis cysteine proteinases (gingipains) have been associated with virulence in destructive periodontitis, a disease process variously considered to represent an unregulated stimulation of either T helper type 1 (Th1)- or Th2-type cells. Critical in maintaining Th1 activity is the response of T lymphocytes to environmental interleukin 12 (IL-12) in the form of up-regulation of gamma interferon (IFN-γ) production. Here we demonstrate that in the presence or absence of serum, gingipains were able to hydrolyze IL-12 and reduce the IL-12-induced IFN-γ production from CD4+ T cells. However, the induction of IL-12 receptors on T cells by gingipains did not correlate with the enhancement of IFN-γ production. The gingipains cleaved IL-12 within the COOH-terminal region of the p40 and p35 subunit chains, which leads to IL-12 inactivity, whereas IL-2 in these assays was not affected. Inactivation of IL-12 by the gingipains could disrupt the cytokine balance or favor Th2 activities in the progression of periodontitis.

scholarly journals Modulation of an Interleukin-12 and Gamma Interferon Synergistic Feedback Regulatory Cycle of T-Cell and Monocyte Cocultures by Porphyromonas gingivalis Lipopolysaccharide in the Absence or Presence of Cysteine Proteinases

2002 ◽  
Vol 70 (10) ◽  
pp. 5695-5705 ◽  
Author(s):  
Peter L. W. Yun ◽  
Arthur A. DeCarlo ◽  
Charles Collyer ◽  
Neil Hunter
Keyword(s):  
T Cells ◽  
T Cell ◽  
Porphyromonas Gingivalis ◽  
Gamma Interferon ◽  
Periodontal Pathogen ◽  
Interleukin 12 ◽  
Minor Role ◽  
Cysteine Proteinases ◽  
Activated T Cells ◽  
Ifn Γ

ABSTRACT Interleukin 12 (IL-12) is an efficient inducer and enhancer of gamma interferon (IFN-γ) production by both resting and activated T cells. There is evidence that human monocytes exposed to IFN-γ have enhanced ability to produce IL-12 when stimulated with lipopolysaccharide (LPS). In this study, it was demonstrated that LPS from the oral periodontal pathogen Porphyromonas gingivalis stimulated monocytes primed with IFN-γ to release IL-12, thereby enhancing IFN-γ accumulation in T-cell populations. P. gingivalis LPS was shown to enhance IL-12 induction of IFN-γ in T cells in a manner independent from TNF-α contribution. The levels of T-cell IL-12 receptors were not affected by P. gingivalis LPS and played only a minor role in the magnitude of the IFN-γ response. These data suggest that LPS from P. gingivalis establishes an activation loop with IL-12 and IFN-γ with potential to augment the production of inflammatory cytokines in relation to the immunopathology of periodontitis. We previously reported that the major cysteine proteinases (gingipains) copurifying with LPS in this organism were responsible for reduced IFN-γ accumulation in the presence of IL-12. However, the addition of the gingipains in the presence of LPS resulted in partial restoration of the IFN-γ levels. In the destructive periodontitis lesion, release of gingipains from the outer membrane (OM) of P. gingivalis could lead to the downregulation of Th1 responses, while gingipain associated with LPS in the OM or in OM vesicles released from the organism could have net stimulatory effects.

scholarly journals CD8 T Cells in Innate Immune Responses: Using STAT4-Dependent but Antigen-Independent Pathways to Gamma Interferon during Viral Infection

mBio ◽  
2014 ◽  
Vol 5 (5) ◽  
Author(s):  
Jenny E. Suarez-Ramirez ◽  
Margarite L. Tarrio ◽  
Kwangsin Kim ◽  
Delia A. Demers ◽  
Christine A. Biron
Keyword(s):  
Innate Immunity ◽  
T Cells ◽  
Immune Responses ◽  
Cd8 T Cells ◽  
Gamma Interferon ◽  
Innate Immune ◽  
Interleukin 12 ◽  
Innate Immune Responses ◽  
Ifn Γ

ABSTRACT The cytokine gamma interferon (IFN-γ), with antimicrobial and immunoregulatory functions, can be produced by T cells following stimulation through their T cell receptors (TCRs) for antigen. The innate cytokines type 1 IFNs and interleukin-12 (IL-12) can also stimulate IFN-γ production by natural killer (NK) but not naive T cells. High basal expression of signal transducer and activator of transcription 4 (STAT4), used by type 1 IFN and IL-12 to induce IFN-γ as well as CD25, contributes to the NK cell responses. During acute viral infections, antigen-specific CD8 T cells are stimulated to express elevated STAT4 and respond to the innate factors with IFN-γ production. Little is known about the requirements for cytokine compared to TCR stimulation. Primary infections of mice with lymphocytic choriomeningitis virus (LCMV) demonstrated that although the elicited antigen-specific CD8 T cells acquired STAT4-dependent innate cytokine responsiveness for IFN-γ and CD25 induction ex vivo, TCR stimulation induced these through STAT4-independent pathways. During secondary infections, LCMV-immune CD8 T cells had STAT4-dependent IFN-γ expression at times of innate cytokine induction but subsequently expanded through STAT4-independent pathways. At times of innate cytokine responses during infection with the antigen-distinct murine cytomegalovirus virus (MCMV), NK and LCMV-immune CD8 T cells both had activation of pSTAT4 and IFN-γ. The T cell IFN-γ response was STAT4 and IL-12 dependent, but antigen-dependent expansion was absent. By dissecting requirements for STAT4 and antigen, this work provides novel insights into the endogenous regulation of cytokine and proliferative responses and demonstrates conditioning of innate immunity by experience. IMPORTANCE Understanding the regulation and function of adaptive immunity is key to the development of new and improved vaccines. Its CD8 T cells are activated through antigen-specific receptors to contribute to long-lasting immunity after natural infections or purposeful immunization. The antigen-receptor pathway of stimulation can lead to production of gamma interferon (IFN-γ), a cytokine having both direct antimicrobial and immunoregulatory functions. Natural killer cells can also produce IFN-γ in response to the innate cytokines type 1 IFNs and/or interleukin-12. This work demonstrates that CD8 T cells acquire parallel responsiveness to innate cytokine signaling for IFN-γ expression during their selection and development and maintain this capability to participate in innate immune responses as long-lived memory cells. Thus, CD8 T cells are conditioned to play a role in innate immunity, and their presence under immune conditions has the potential to regulate resistance to either secondary challenges or primary infections with unrelated agents.

scholarly journals Populations of Human T Lymphocytes That Traverse the Vascular Endothelium Stimulated by Borrelia burgdorferi Are Enriched with Cells That Secrete Gamma Interferon

2004 ◽  
Vol 72 (3) ◽  
pp. 1530-1536 ◽  
Author(s):  
Edna I. Gergel ◽  
Martha B. Furie
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Vascular Endothelium ◽  
Human Peripheral Blood ◽  
Gamma Interferon ◽  
Interleukin 4 ◽  
Ifn Γ

ABSTRACT Some diseases are characterized by prevalence in the affected tissues of type 1 T lymphocytes, which secrete gamma interferon (IFN-γ) and other proinflammatory cytokines. For example, type 1 T cells predominate in the lesions of patients with Lyme disease, which is caused by the bacterium Borrelia burgdorferi. We used an in vitro model of the blood vessel wall to test the premise that the vascular endothelium actively recruits circulating type 1 T cells to such lesions. When T lymphocytes isolated from human peripheral blood were examined, the populations that traversed monolayers of resting human umbilical vein endothelial cells (HUVEC) or HUVEC stimulated by interleukin-1β or B. burgdorferi were markedly enriched for T cells that produced IFN-γ compared to the initially added population of T cells. No enrichment was seen for cells that produced interleukin-4, a marker for type 2 T lymphocytes. Very late antigen-4 and CD11/CD18 integrins mediated passage of the T cells across both resting and stimulated HUVEC, and the endothelium-derived chemokine CCL2 (monocyte chemoattractant protein 1) was responsible for the enhanced migration of T cells across stimulated HUVEC. These results suggest that the vascular endothelium may contribute to the selective accumulation of type 1 T cells in certain pathological lesions, including those of Lyme disease.

scholarly journals Interdependency of Interleukin-10 and Interleukin-12 in Regulation of T-Cell Differentiation and Effector Function of Monocytes in Response to Stimulation withCryptococcus neoformans

2001 ◽  
Vol 69 (10) ◽  
pp. 6064-6073 ◽  
Author(s):  
Cinzia Retini ◽  
Thomas R. Kozel ◽  
Donatella Pietrella ◽  
Claudia Monari ◽  
Francesco Bistoni ◽  
...  
Keyword(s):  
T Cells ◽  
Critical Role ◽  
Principal Component ◽  
Interleukin 10 ◽  
Interleukin 12 ◽  
T Helper ◽  
Ifn Γ ◽  
Capsular Material ◽  
Type Response

ABSTRACT We previously demonstrated that the principal component of capsular material of Cryptococcus neoformans, glucuronoxylomannan (GXM), induces interleukin-10 (IL-10) secretion from human monocytes. Here we report that encapsulation of the yeast with GXM is able to down-regulate interleukin-12 (IL-12) production by monocytes that would normally occur in the absence of encapsulation. This phenomenon appeared to be the result of inhibition of the phagocytic process by encapsulation with GXM as well as of negative signals such as IL-10 secretion produced by interaction of GXM with leukocytes. Decreased secretion of IL-12 correlated with decreased release of gamma interferon (IFN-γ) from T cells, suggesting a role for encapsulation with GXM in hindering a T helper type 1 (Th1) response. This is supported by the ability of encapsulation with GXM to limit increased expression of B7-1 costimulatory molecules that otherwise might limit IL-10 secretion. Endogenous IL-10 played a critical role in modulatory activity associated with encapsulation with GXM. Blocking IL-10 with monoclonal antibody to IL-10 resulted in increased (i) IL-12 secretion, (ii) IFN-γ release from T cells, and (iii) killing of C. neoformans by monocytes. These results suggest that encapsulation with GXM limits development of a protective Th1-type response, an inhibitory process in which IL-10 plays a critical role. Scavengers of GXM and/or IL-10 could be useful in a protective Th1-type response in patients with cryptococcosis.

scholarly journals Residual Type 1 Immunity in Patients Genetically Deficient for Interleukin 12 Receptor β1 (IL-12Rβ1)

2000 ◽  
Vol 192 (4) ◽  
pp. 517-528 ◽  
Author(s):  
Claudia E. Verhagen ◽  
Tjitske de Boer ◽  
Hermelijn H. Smits ◽  
Frank A.W. Verreck ◽  
Eddy A. Wierenga ◽  
...  
Keyword(s):  
T Cells ◽  
Map Kinase ◽  
Map Kinases ◽  
Partial Agonist ◽  
Surface Expression ◽  
Mitogen Activated Protein Kinase ◽  
Cell Surface Expression ◽  
Interleukin 12 ◽  
Ifn Γ

Genetic lack of interleukin 12 receptor β1 (IL-12Rβ1) surface expression predisposes to severe infections by poorly pathogenic mycobacteria or Salmonella and causes strongly decreased, but not completely abrogated, interferon (IFN)-γ production. To study IL-12Rβ1–independent residual IFN-γ production, we have generated mycobacterium–specific T cell clones (TCCs) from IL-12Rβ1–deficient individuals. All TCCs displayed a T helper type 1 phenotype and the majority responded to IL-12 by increased IFN-γ production and proliferative responses upon activation. This response to IL-12 could be further augmented by exogenous IL-18. IL-12Rβ2 was found to be normally expressed in the absence of IL-12Rβ1, and could be upregulated by IFN-α. Expression of IL-12Rβ2 alone, however, was insufficient to induce signal transducer and activator of transcription (Stat)4 activation in response to IL-12, whereas IFN-α/IFN-αR ligation resulted in Stat4 activation in both control and IL-12Rβ1–deficient cells. IL-12 failed to upregulate cell surface expression of IL-18R, integrin α6, and IL-12Rβ2 on IL-12Rβ1–deficient cells, whereas this was normal on control cells. IL-12–induced IFN-γ production in IL-12Rβ1–deficient T cells could be inhibited by the p38 mitogen-activated protein kinase (MAP) kinase inhibitor SB203580 and the MAP kinase kinase (MEK) 1/2 inhibitor U0126, suggesting involvement of MAP kinases in this alternative, Stat4-independent, IL-12 signaling pathway. Collectively, these results indicate that IL-12 acts as a partial agonist in the absence of IL-12Rβ1. Moreover, the results reveal the presence of a novel IL-12Rβ1/Stat4–independent pathway of IL-12 responsiveness in activated human T cells involving MAP kinases. This pathway is likely to play a role in the residual type 1 immunity in IL-12Rβ1 deficiency.

scholarly journals Rapid Development of a Gamma Interferon-Secreting Glycolipid/CD1d-Specific Vα14+ NK1.1− T-Cell Subset after Bacterial Infection

2006 ◽  
Vol 74 (10) ◽  
pp. 5903-5913 ◽  
Author(s):  
Masashi Emoto ◽  
Izumi Yoshizawa ◽  
Yoshiko Emoto ◽  
Mamiko Miamoto ◽  
Robert Hurwitz ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Bacterial Infection ◽  
Rapid Development ◽  
Cell Subset ◽  
Gamma Interferon ◽  
Interleukin 12 ◽  
T Cell Subset ◽  
Early Stages ◽  
Ifn Γ

ABSTRACT The phenotypic and functional changes of glycolipid presented by CD1d(glycolipid/CD1d) specific Vα14+ T cells in the liver of mice at early stages of bacterial infection were investigated. After Listeria monocytogenes infection or interleukin-12 (IL-12) treatment, α-galactosylceramide/CD1d tetramer-reactive (α-GalCer/CD1d+) T cells coexpressing natural killer (NK) 1.1 marker became undetectable and, concomitantly, cells lacking NK1.1 emerged in both euthymic and thymectomized animals. Depletion of the NK1.1+ subpopulation prevented the emergence of α-GalCer/CD1d+ NK1.1− T cells. Before infection, NK1.1+, rather than NK1.1−, α-GalCer/CD1d+ T cells coexpressing CD4 were responsible for IL-4 production, whereas gamma interferon (IFN-γ) was produced by cells regardless of NK1.1 or CD4 expression. After infection, IL-4-secreting cells became undetectable among α-GalCer/CD1d+ T cells, but considerable numbers of IFN-γ-secreting cells were found among NK1.1−, but not NK1.1+, cells lacking CD4. Thus, NK1.1 surface expression and functional activities of Vα14+ T cells underwent dramatic changes at early stages of listeriosis, and these alterations progressed in a thymus-independent manner. In mutant mice lacking all α-GalCer/CD1d+ T cells listeriosis was ameliorated, suggesting that the subtle contribution of the NK1.1− T-cell subset to antibacterial protection is covered by more profound detrimental effects of the NK1.1+ T-cell subset.

scholarly journals Protection against Intestinal Amebiasis by a Recombinant Vaccine Is Transferable by T Cells and Mediated by Gamma Interferon

2009 ◽  
Vol 77 (9) ◽  
pp. 3909-3918 ◽  
Author(s):  
Xiaoti Guo ◽  
Lisa Barroso ◽  
Steven M. Becker ◽  
David M. Lyerly ◽  
Thomas S. Vedvick ◽  
...  
Keyword(s):  
T Cells ◽  
Gamma Interferon ◽  
Interleukin 12 ◽  
Necrosis Factor Alpha ◽  
Vaccine Protection ◽  
Adjuvant System ◽  
Factor Alpha ◽  
Ifn Γ ◽  
Intestinal Amebiasis

ABSTRACT We have previously shown that vaccination with purified Entamoeba histolytica Gal/GalNAc lectin or recombinant subunits can protect mice from intestinal amebiasis upon intracecal challenge. In this study, we demonstrated with adoptive-transfer experiments that this lectin vaccine protection is mediated by T cells but not serum. The cell-mediated immune (CMI) response was characterized by significant gamma interferon (IFN-γ), interleukin 12 (IL-12), IL-2, IL-10, and IL-17 production. To move toward a human vaccine, we switched to a recombinant protein and tested a range of adjuvants and routes appropriate for humans. We found that subcutaneous delivery of LecA with IDRI's adjuvant system EM014 elicited a potent Th1-type CMI profile and provided significant protection, as measured by culture negativity (79% efficacy); intranasal immunization with cholera toxin provided 56% efficacy; and alum induced a Th2-type response that protected 62 to 68% of mice. Several antibody and CMI cytokine responses were examined for correlates of protection, and prechallenge IFN-γ+ or IFN-γ-, IL-2-, and tumor necrosis factor alpha-triple-positive CD4 cells in blood were statistically associated with protection. To test the role of IFN-γ in LecA-mediated protection, we neutralized IFN-γ in LecA-immunized mice and found that it abrogated the protection conferred by vaccination. These data demonstrate that CMI is sufficient for vaccine protection from intestinal amebiasis and reveal an important role for IFN-γ, even in the setting of alum.

scholarly journals Gamma Interferon-Independent Effects of Interleukin-12 on Immunity to Salmonella enterica Serovar Typhimurium

2007 ◽  
Vol 75 (12) ◽  
pp. 5753-5762 ◽  
Author(s):  
Jason D. Price ◽  
Kim R. Simpfendorfer ◽  
Radhakrishnam R. Mantena ◽  
James Holden ◽  
William R. Heath ◽  
...  
Keyword(s):  
T Cells ◽  
Salmonella Enterica ◽  
Bacterial Load ◽  
Bacterial Pathogen ◽  
Cell Receptor ◽  
Gamma Interferon ◽  
Interleukin 12 ◽  
Mesenteric Lymph Nodes ◽  
Serovar Typhimurium ◽  
Ifn Γ

ABSTRACTInterleukin-12 (IL-12) and IL-18 are both central to the induction of gamma interferon (IFN-γ), and various roles for IL-12 and IL-18 in control of intracellular microbial infections have been demonstrated. We used IL-12p40−/−and IL-18−/−mice to further investigate the role of IL-12 and IL-18 in control ofSalmonella entericaserovar Typhimurium. While C57BL/6 and IL-18−/−mice were able to resolve attenuatedS. entericaserovar Typhimurium infections, the IL-12p40−/−mice succumbed to a high bacterial burden after 60 days. Using ovalbumin (OVA)-specific T-cell receptor transgenic T cells (OT-II cells), we demonstrated that following oral infection with recombinantS. entericaserovar Typhimurium expressing OVA, the OT-II cells proliferated in the mesenteric lymph nodes of C57BL/6 and IL-18−/−mice but not in IL-12p40−/−mice. In addition, we demonstrated by flow cytometry that equivalent or increased numbers of T cells produced IFN-γ in IL-12p40−/−mice compared with the numbers of T cells that produced IFN-γ in C57BL/6 and IL-18−/−mice. Finally, we demonstrated that removal of macrophages fromS. entericaserovar Typhimurium-infected C57BL/6 and IL-12p40−/−mice did not affect the bacterial load, suggesting that impaired control ofS. entericaserovar Typhimurium infection in the absence of IL-12p40 is not due to reduced macrophage bactericidal activities, while IL-18−/−mice did rely on the presence of macrophages for control of the infection. Our results suggest that IL-12p40, but not IL-18, is critical to resolution of infections with attenuatedS. entericaserovar Typhimurium and that especially the effects of IL-12p40 on proliferative responses of CD4+T cells, but not the ability of these cells to produce IFN-γ, are important in the resolution of infection by this intracellular bacterial pathogen.

scholarly journals STAT1 Is Essential for Antimicrobial Effector Function but Dispensable for Gamma Interferon Production during Toxoplasma gondii Infection

2004 ◽  
Vol 72 (3) ◽  
pp. 1257-1264 ◽  
Author(s):  
L. Cristina Gavrilescu ◽  
Barbara A. Butcher ◽  
Laura Del Rio ◽  
Gregory A. Taylor ◽  
Eric Y. Denkers
Keyword(s):  
T Cell ◽  
Toxoplasma Gondii ◽  
Intracellular Signaling ◽  
Acute Infection ◽  
Gamma Interferon ◽  
Interleukin 12 ◽  
Ifn Γ ◽  
Toxoplasma Gondii Infection ◽  
Oxide Synthase

ABSTRACT The opportunistic protozoan Toxoplasma gondii is a prototypic Th1-inducing pathogen inducing strong gamma interferon (IFN-γ) cytokine responses that are required to survive infection. Intracellular signaling intermediate STAT1 mediates many effects of IFN-γ and is implicated in activation of T-bet, a master regulator of Th1 differentiation. Here, we show that T. gondii-infected STAT1-null mice fail to upregulate the IFN-γ-dependent effector molecules inducible nitric oxide synthase (iNOS), IGTP, and LRG-47, which are required for mice to survive infection. Both T-bet and interleukin-12 receptor β2 (IL-12Rβ2) failed to undergo normal upregulation in response to T. gondii. Development of IFN-γ-producing CD4+ and CD8+ T lymphocytes was severely curtailed in the absence of STAT1, but a substantial level of STAT1-independent non-T-cell-derived IFN-γ was induced. Absence of STAT1 also resulted in increased IL-4, Arg1, Ym1, and Fizz1, markers of Th2 differentiation and alternative macrophage activation. Together, the results show that T. gondii induces STAT1-dependent T-lymphocyte and STAT1-independent non-T-cell IFN-γ production, but that effector functions of this type 1 cytokine cannot operate in the absence of STAT1, resulting in extreme susceptibility to acute infection.

scholarly journals LACK-Specific CD4+ T Cells That Induce Gamma Interferon Production in Patients with Localized Cutaneous Leishmaniasis during an Early Stage of Infection

2002 ◽  
Vol 70 (6) ◽  
pp. 3122-3129 ◽  
Author(s):  
Eliane Bourreau ◽  
Ghislaine Prévot ◽  
Jacques Gardon ◽  
Roger Pradinaud ◽  
Hitoshi Hasagewa ◽  
...  
Keyword(s):  
T Cells ◽  
Early Stage ◽  
Interleukin 10 ◽  
Gamma Interferon ◽  
Effector Memory ◽  
Cellular Source ◽  
Effector Memory Cells ◽  
Ifn Γ

ABSTRACT The profile of cytokines induced by soluble leishmania antigen (SLA) and the Leishmania homologue of the mammalian receptor for activated C kinase (LACK), a candidate vaccine against leishmaniasis, and the cellular source of the cytokines produced in response to these antigens were analyzed in patients infected with Leishmania guyanensis. Gamma interferon (IFN-γ) and interleukin-10 (IL-10) were produced in response to LACK. Although LACK-specific CD4+ cells producing IFN-γ were isolated only during the early phase of infection (less than 30 days following the onset of infection), cells producing IL-10 in response to LACK were detected in all patients. CD4+ T cells producing IFN-γ and IL-13 were produced in response to SLA in all patients. SLA- and LACK-specific T cells are effector memory cells, as they are CD45RA− CCR7− CD4+ T cells. CD4+ T cells producing IFN-γ are CD62L−, and CD4+ T cells producing IL-10 are CD62L+, indicating that these cells have different tissue-homing capacities. These findings show that SLA and LACK induce both type 1 (IFN-γ) and type 2 (IL-10 or IL-13) cell responses.

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