Characterization of Early Gamma Interferon (IFN-γ) Expression during Murine Listeriosis: Identification of NK1.1+ CD11c+ Cells as the Primary IFN-γ-Expressing Cells

ABSTRACT Though it is well established that gamma interferon (IFN-γ) is crucial to the early innate defense of murine listeriosis, its sources remain controversial. In this study, intracellular cytokine staining of IFN-γ-expressing splenocytes early after Listeria monocytogenes infection revealed that NK1.1+, CD11c+, CD8+ T, and CD4+ T cells expressed IFN-γ 24 h after infection. Contrary to the previous report, most IFN-γ+ dendritic cells (DC) were CD8α− DC. Unexpectedly, almost all CD11c+ IFN-γ-expressing cells also expressed NK1.1. These NK1.1+ CD11c+ cells represented primary IFN-γ-expressing cells after infection. In situ studies showed these NK1.1+ CD11c+ cells were recruited to the borders of infectious foci and expressed IFN-γ. A significant NK1.1+ CD11c+ population was found in uninfected spleen, lymph node, blood, and bone marrow cells. And its number increased significantly in spleen, lymph node, and bone marrow after L. monocytogenes infection. Using interleukin-12 (IL-12) p40−/− mice, IFN-γ expression was found to be largely IL-12 p40 dependent, and the number of IFN-γ-expressing cells was only about one-third of that of wild-type mice. Moreover, the IFN-γ expression was absolutely dependent on live L. monocytogenes infection, as no IFN-γ was detected after inoculation of heat-killed L. monocytogenes. Our findings not only provide an insight into IFN-γ expression after in vivo infection but may also change the current perceptions of DC and natural killer cells.

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Beryllium, an Adjuvant That Promotes Gamma Interferon Production

Infection and Immunity ◽

10.1128/iai.68.7.4032-4039.2000 ◽

2000 ◽

Vol 68 (7) ◽

pp. 4032-4039 ◽

Cited By ~ 14

Author(s):

Julia Y. Lee ◽

Olga Atochina ◽

Benjamin King ◽

Leslie Taylor ◽

Merle Elloso ◽

...

Keyword(s):

Lymph Node ◽

Gamma Interferon ◽

Effective Control ◽

Interleukin 12 ◽

Spleen Cells ◽

Th2 Response ◽

Th1 Response ◽

Ifn Γ

ABSTRACT Beryllium is associated with a human pulmonary granulomatosis characterized by an accumulation of CD4+ T cells in the lungs and a heightened specific lymphocyte proliferative response to beryllium (Be) with gamma interferon (IFN-γ) release (i.e., a T helper 1 [Th1] response). While an animal model of Be sensitization is not currently available, Be has exhibited adjuvant effects in animals. The effects of Be on BALB/c mice immunized with soluble leishmanial antigens (SLA) were investigated to determine if Be had adjuvant activity for IFN-γ production, an indicator of the Th1 response. In this strain of Leishmania-susceptible BALB/c mice, a Th2 response is normally observed after in vivo SLA sensitization and in vitro restimulation with SLA. If interleukin-12 (IL-12) is given during in vivo sensitization with SLA, markedly increased IFN-γ production and decreased IL-4 production are detected. We show here that when beryllium sulfate (BeSO4) was added during in vivo sensitization of BALB/c mice with SLA and IL-12, significantly increased IFN-γ production and decreased IL-4 production from lymph node and spleen cells were detected upon in vitro SLA restimulation. No specific responses were observed to Be alone. Lymph node and spleen cells from all mice proliferated strongly and comparably upon in vitro restimulation with SLA and with SLA plus Be; no differences were noted among groups of mice that received different immunization regimens. In vivo, when Be was added to SLA and IL-12 for sensitization of BALB/c mice, more effective control ofLeishmania infection was achieved. This finding has implications for understanding not only the development of granulomatous reactions but also the potential for developing Be as a vaccine adjuvant.

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Resistance to Acute Babesiosis Is Associated with Interleukin-12- and Gamma Interferon-Mediated Responses and Requires Macrophages and Natural Killer Cells

Infection and Immunity ◽

10.1128/iai.71.4.2002-2008.2003 ◽

2003 ◽

Vol 71 (4) ◽

pp. 2002-2008 ◽

Cited By ~ 43

Author(s):

Irma Aguilar-Delfin ◽

Peter J. Wettstein ◽

David H. Persing

Keyword(s):

Nk Cells ◽

Gamma Interferon ◽

Interleukin 12 ◽

No Production ◽

Cytokine Responses ◽

Early Production ◽

Ifn Γ ◽

Crucial Part

ABSTRACT We examined the role of the cytokines gamma interferon (IFN-γ) and interleukin-12 (IL-12) in the model of acute babesiosis with the WA1 Babesia. Mice genetically deficient in IFN-γ-mediated responses (IFNGR2KO mice) and IL-12-mediated responses (Stat4KO mice) were infected with the WA1 Babesia, and observations were made on the course of infection and cytokine responses. Levels of IFN-γ and IL-12 in serum increased 24 h after parasite inoculation. The augmented susceptibility observed in IFNGR2KO and Stat-4KO mice suggests that the early IL-12- and IFN-γ-mediated responses are involved in protection against acute babesiosis. Resistance appears to correlate with an increase in nitric oxide (NO) production. In order to assess the contribution of different cell subsets to resistance against the parasite, we also studied mice lacking B cells, CD4+ T cells, NK cells, and macrophages. Mice genetically deficient in B lymphocytes or CD4+ T lymphocytes were able to mount protective responses comparable to those of immunosufficient mice. In contrast, in vivo depletion of macrophages or NK cells resulted in elevated susceptibility to the infection. Our observations suggest that a crucial part of the response that protects from the pathogenic Babesia WA1 is mediated by macrophages and NK cells, probably through early production of IL-12 and IFN-γ, and induction of macrophage-derived effector molecules like NO.

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Legionella pneumophila Evades Gamma Interferon-Mediated Growth Suppression through Interleukin-10 Induction in Bone Marrow-Derived Macrophages

Infection and Immunity ◽

10.1128/iai.73.5.2709-2717.2005 ◽

2005 ◽

Vol 73 (5) ◽

pp. 2709-2717 ◽

Cited By ~ 16

Author(s):

Sadako Yoshizawa ◽

Kazuhiro Tateda ◽

Tetsuya Matsumoto ◽

Fumio Gondaira ◽

Shuichi Miyazaki ◽

...

Keyword(s):

Bone Marrow ◽

Cross Talk ◽

Legionella Pneumophila ◽

Interleukin 10 ◽

Gamma Interferon ◽

Protein Component ◽

Interleukin 12 ◽

Cellular Mechanisms ◽

Ifn Γ ◽

Culture Supernatants

ABSTRACT We examined the roles of Th1-Th2 cytokine cross talk in Legionella pneumophila-infected bone marrow-derived (BM) macrophages in the presence of costimulation with interleukin-12 (IL-12) and IL-18. Treatment with gamma interferon (IFN-γ) alone or treatment with IL-12 in combination with IL-18 resulted in a 3- or 2-log reduction in bacterial numbers, respectively, in BM macrophages, whereas treatment with IL-12 or IL-18 alone had no effect. Significant amounts of IFN-γ were detected in the culture supernatants of infected macrophages stimulated with IL-12 and IL-18 in combination but not independently. Neutralization of IFN-γ by antibody completely abolished the growth inhibitory effects of IL-12 and IL-18. Interestingly, higher infectivity ratios of L. pneumophila or the addition of increasing concentrations of heat-killed bacteria (HKB) suppressed the production of IFN-γ, which resulted in the increased intracellular growth of bacteria. Significant amounts of IL-10 were detected in culture supernatants when Legionella-infected macrophages were cocultured with HKB. Furthermore, neutralization of IL-10 by antibody resulted in an increase in IFN-γ production by infected BM macrophages when cocultured with HKB. Treatment of HKB with trypsin but not polymyxin B attenuated the growth-promoting effects of HKB, suggesting the involvement of a protein component(s) in regulation of the growth of L. pneumophila. These findings demonstrate a crucial role of Th1-Th2 cross talk in L. pneumophila-infected BM macrophages. Our results also suggest that L. pneumophila modulates the cytokine balance from IFN-γ-driven Th1 to more Th2 responses, likely through the induction of IL-10 by a bacterial protein component(s). These data provide new insights not only into the cellular mechanisms of Th1-Th2 cross talk in Legionella-infected macrophages but also into the pathogenesis of L. pneumophila pneumonia in humans.

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

Infection and Immunity ◽

10.1128/iai.67.7.3593-3600.1999 ◽

1999 ◽

Vol 67 (7) ◽

pp. 3593-3600 ◽

Cited By ~ 121

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.

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Gamma Interferon (IFN-γ) and IFN-γ-Inducing Cytokines Interleukin-12 (IL-12) and IL-18 Do Not Augment Infection-Stimulated Bone Resorption In Vivo

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.11.1.106-110.2004 ◽

2004 ◽

Vol 11 (1) ◽

pp. 106-110 ◽

Cited By ~ 36

Author(s):

Hajime Sasaki ◽

Khaled Balto ◽

Nobuyuki Kawashima ◽

Jean Eastcott ◽

Katsuaki Hoshino ◽

...

Keyword(s):

Bone Resorption ◽

Alveolar Bone ◽

Interleukin 1 ◽

Bone Destruction ◽

Gamma Interferon ◽

Interleukin 12 ◽

Wild Type ◽

Necrosis Factor Alpha ◽

Ifn Γ

ABSTRACT Periapical granulomas are induced by bacterial infection of the dental pulp and result in destruction of the surrounding alveolar bone. In previous studies we have reported that the bone resorption in this model is primarily mediated by macrophage-expressed interleukin-1 (IL-1). The expression and activity of IL-1 is in turn modulated by a network of Th1 and Th2 regulatory cytokines. In the present study, the functional roles of the Th1 cytokine gamma interferon (IFN-γ) and IFN-γ-inducing cytokines IL-12 and IL-18 were determined in a murine model of periapical bone destruction. IL-12−/−, IL-18−/−, and IFN-γ−/− mice were subjected to surgical pulp exposure and infection with a mixture of four endodontic pathogens, and bone destruction was determined by microcomputed tomography on day 21. The results indicated that all IL-12−/−, IL-18−/−, and IFN-γ−/− mice had similar infection-stimulated bone resorption in vivo as wild-type control mice. Mice infused with recombinant IL-12 also had resorption similar to controls. IFN-γ−/− mice exhibited significant elevations in IL-6, IL-10, IL-12, and tumor necrosis factor alpha in lesions compared to wild-type mice, but these modulations had no net effect on IL-1α levels. Recombinant IL-12, IL-18, and IFN-γ individually failed to consistently modulate macrophage IL-1α production in vitro. We conclude that, at least individually, endogenous IL-12, IL-18, and IFN-γ do not have a significant effect on the pathogenesis of infection-stimulated bone resorption in vivo, suggesting possible functional redundancy in proinflammatory pathways.

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Gamma Interferon Is Dispensable for Neopterin Production In Vivo

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.12.12.1437-1441.2005 ◽

2005 ◽

Vol 12 (12) ◽

pp. 1437-1441 ◽

Cited By ~ 5

Author(s):

R. Sghiri ◽

J. Feinberg ◽

F. Thabet ◽

K. Dellagi ◽

J. Boukadida ◽

...

Keyword(s):

Human Monocyte ◽

Gamma Interferon ◽

Interleukin 12 ◽

Enzyme Linked Immunosorbent Assay ◽

Deleterious Mutations ◽

Serum Neopterin ◽

Ifn Γ ◽

Dependent Pathway

ABSTRACT Previous studies have indicated that neopterin is synthesized in vitro by human monocyte-derived macrophages and dendritic cells upon stimulation with gamma interferon (IFN-γ). Neopterin production under specific conditions in vitro has also been obtained upon stimulation with IFN-α and/or IFN-β. However, it is unknown if any IFN-γ-independent neopterin synthesis is possible in vivo. In the present study we investigated the serum neopterin concentrations in patients affected by the syndrome of Mendelian susceptibility to mycobacterial disease (MSMD). Indeed, this syndrome is characterized by deeply impaired or absent IFN-γ production or function due to severe mutations in molecules involved in IFN-γ/interleukin-12 (IL-12)/IL-23-dependent pathway. Serum neopterin levels were measured by an enzyme-linked immunosorbent assay in 27 patients with MSMD. We found that serum neopterin levels are elevated in the complete absence of IFN-γ activity due either to a complete deficiency of its receptor or to deleterious mutations of IL-12 or its receptor. These data clearly indicate that, as reported from in vitro studies, other stimuli are able to induce neopterin synthesis in vivo. Consequently, neopterin cannot be used as means of diagnosis of MSMD due to IFN-γ-, IL-12-, and IL-23-dependent pathway defects.

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Interleukin-12 Promotes Gamma Interferon-Dependent Neutrophil Recruitment in the Lung and Improves Protection against Respiratory Streptococcus pneumoniae Infection

Infection and Immunity ◽

10.1128/iai.01403-06 ◽

2007 ◽

Vol 75 (3) ◽

pp. 1196-1202 ◽

Cited By ~ 105

Author(s):

Keer Sun ◽

Sharon L. Salmon ◽

Steven A. Lotz ◽

Dennis W. Metzger

Keyword(s):

Streptococcus Pneumoniae ◽

Survival Rates ◽

Gamma Interferon ◽

Neutrophil Recruitment ◽

Interleukin 12 ◽

Necrosis Factor Alpha ◽

Innate Defense ◽

Tnf Α ◽

Ifn Γ

ABSTRACT The ability of exogenous interleukin-12 (IL-12) to elicit protective innate immune responses against the extracellular pathogen Streptococcus pneumoniae was tested by infecting BALB/c mice intranasally (i.n.) with S. pneumoniae after i.n. administration of IL-12. It was found that administration of IL-12 resulted in lower bacterial burdens in the infected mice and significantly improved survival rates. All IL-12-treated mice contained higher levels of pulmonary gamma interferon (IFN-γ) after infection and significantly more neutrophils than infected mice not treated with IL-12. IFN-γ was found to be essential for IL-12-induced resistance and for neutrophil influx into the lungs, and the observed changes correlated with increased levels of the IL-8 homologue keratinocyte-derived chemokine (KC). In addition, in vitro tumor necrosis factor alpha (TNF-α) production by alveolar macrophages stimulated with heat-killed pneumococci was enhanced by IFN-γ, and TNF-α in turn could enhance production of KC by lung cells. Finally, IL-12-induced protection was dependent upon the presence of neutrophils and the KC receptor CXCR2. Taken together, the results indicate that exogenous IL-12 can improve innate defense in the lung against S. pneumoniae by inducing IFN-γ production, which in turn enhances chemokine expression, and promotes pulmonary neutrophil recruitment into the infected lung. The findings show that IL-12 and IFN-γ can mediate a protective effect against respiratory infection caused by extracellular bacterial pathogens.

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Coactivating Signals for the Hepatic Lymphocyte Gamma Interferon Response to Francisella tularensis

Infection and Immunity ◽

10.1128/iai.01203-06 ◽

2006 ◽

Vol 75 (3) ◽

pp. 1335-1342 ◽

Cited By ~ 16

Author(s):

Jason R. Wickstrum ◽

Kee-Jong Hong ◽

Sirosh Bokhari ◽

Natalie Reed ◽

Nicholas McWilliams ◽

...

Keyword(s):

Francisella Tularensis ◽

Neutralizing Antibodies ◽

Synergistic Effects ◽

Gamma Interferon ◽

Interferon Response ◽

Interleukin 12 ◽

Secondary Site ◽

Ifn Γ

ABSTRACT The facultative intracellular bacterium Francisella tularensis is capable of causing systemic infections in various hosts, including mice and humans. The liver is a major secondary site of F. tularensis infection, but hepatic immune responses to the pathogen remain poorly defined. Immune protection against the pathogen is thought to depend on the cytokine gamma interferon (IFN-γ), but the cellular basis for this response has not been characterized. Here we report that natural killer cells from the livers of naïve uninfected mice produced IFN-γ when challenged with live bacteria in vitro and that the responses were greatly increased by coactivation of the cells with either recombinant interleukin-12 (IL-12) or IL-18. Moreover, the two cytokines had strong synergistic effects on IFN-γ induction. Neutralizing antibodies to either IL-12 or IL-18 inhibited IFN-γ production in vitro, and mice deficient in the p35 subunit of IL-12 failed to show IFN-γ responses to bacterial challenge either in vitro or in vivo. Clinical isolates of highly virulent type A Francisella tularensis subsp. tularensis organisms were comparable to the live attenuated vaccine strain of Francisella tularensis subsp. holarctica in their ability to induce IL-12 and IFN-γ expression. These findings demonstrate that cells capable of mounting IFN-γ responses to F. tularensis are resident within the livers of uninfected mice and depend on coactivation by IL-12 and IL-18 for optimum responses.

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The Function of Gamma Interferon-Inducible GTP-Binding Protein IGTP in Host Resistance to Toxoplasma gondii Is Stat1 Dependent and Requires Expression in Both Hematopoietic and Nonhematopoietic Cellular Compartments

Infection and Immunity ◽

10.1128/iai.70.12.6933-6939.2002 ◽

2002 ◽

Vol 70 (12) ◽

pp. 6933-6939 ◽

Cited By ~ 69

Author(s):

Carmen M. Collazo ◽

George S. Yap ◽

Sara Hieny ◽

Patricia Caspar ◽

Carl G. Feng ◽

...

Keyword(s):

Bone Marrow ◽

Toxoplasma Gondii ◽

Host Resistance ◽

Chronic Infection ◽

Acute Infection ◽

Gamma Interferon ◽

Ifn Γ ◽

Bone Marrow Chimeras

ABSTRACT IGTP is a member of the 47-kDa family of gamma interferon (IFN-γ)-induced GTPases. We have previously shown that IGTP is critical for host resistance to Toxoplasma gondii infection. In the present study, we demonstrate that T. gondii-induced IGTP expression in vivo and IFN-γ-driven synthesis of the protein in vitro are dependent on Stat1. Consistent with this observation, Stat1-deficient animals succumbed to T. gondii infection with the same rapid kinetics as IGTP−/− mice. To ascertain the cellular levels at which IGTP functions in host control of acute infection, we constructed reciprocal bone marrow chimeras between IGTP-deficient and wild-type mice. Resistance to infection was observed only when IGTP was present in both hematopoietic and nonhematopoietic compartments. To assess the possible contribution of IGTP to the maintenance of parasite latency, partial chemotherapy was used to allow the establishment of chronic infection in IGTP-deficient animals. Upon cessation of drug treatment, these animals showed delayed mortality compared with similarly infected and treated IFN-γ-deficient or inducible nitric oxide synthase-deficient mice, which succumbed rapidly. Parallel experiments performed with drug-treated bone marrow chimeras supported a role for the hematopoietic compartment in this NO-dependent, IGTP-independent control of chronic infection. Taken together, our findings demonstrate that host resistance mediated by IGTP is a Stat1-induced function which in the case of T. gondii acts predominantly to restrict acute as opposed to chronic infection. This effector mechanism requires expression of IGTP in cells of both hematopoietic and nonhematopoietic origin. In contrast, in latent infection, hematopoietically derived cells mediate resistance by means of a largely NO-dependent pathway.

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Gamma Interferon Blocks Gammaherpesvirus Reactivation from Latency

Journal of Virology ◽

10.1128/jvi.80.1.192-200.2006 ◽

2006 ◽

Vol 80 (1) ◽

pp. 192-200 ◽

Cited By ~ 53

Author(s):

Ashley L. Steed ◽

Erik S. Barton ◽

Scott A. Tibbetts ◽

Daniel L. Popkin ◽

Mary L. Lutzke ◽

...

Keyword(s):

Immune Surveillance ◽

Viral Gene Expression ◽

Gamma Interferon ◽

Viral Gene ◽

Herpesvirus Infection ◽

Murine Gammaherpesvirus ◽

Ifn Γ ◽

Gammaherpesvirus 68 ◽

Novel Strategy

ABSTRACT Establishment of latent infection and reactivation from latency are critical aspects of herpesvirus infection and pathogenesis. Interfering with either of these steps in the herpesvirus life cycle may offer a novel strategy for controlling herpesvirus infection and associated disease pathogenesis. Prior studies show that mice deficient in gamma interferon (IFN-γ) or the IFN-γ receptor have elevated numbers of cells reactivating from murine gammaherpesvirus 68 (γHV68) latency, produce infectious virus after the establishment of latency, and develop large-vessel vasculitis. Here, we demonstrate that IFN-γ is a powerful inhibitor of reactivation of γHV68 from latency in tissue culture. In vivo, IFN-γ controls viral gene expression during latency. Importantly, depletion of IFN-γ in latently infected mice results in an increased frequency of cells reactivating virus. This demonstrates that IFN-γ is important for immune surveillance that limits reactivation of γHV68 from latency.

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