Enhanced Replication of Leishmania amazonensis Amastigotes in Gamma Interferon-Stimulated Murine Macrophages: Implications for the Pathogenesis of Cutaneous Leishmaniasis

ABSTRACT During Leishmania major infection in mice, gamma interferon (IFN-γ) plays an essential role in controlling parasite growth and disease progression. In studies designed to ascertain the role of IFN-γ in Leishmania amazonensis infection, we were surprised to find that IFN-γ could promote L. amazonensis amastigote replication in macrophages (MΦs), although it activated MΦs to kill promastigotes. The replication-promoting effect of IFN-γ on amastigotes was independent of the source and genetic background of MΦs, was apparently not affected by surface opsonization of amastigotes, was not mediated by interleukin-10 or transforming growth factor β, and was observed at different temperatures. Consistent with the different fates of promastigotes and amastigotes in IFN-γ-stimulated MΦs, L. amazonensis-specific Th1 transfer helped recipient mice control L. amazonensis infection established by promastigotes but not L. amazonensis infection established by amastigotes. On the other hand, IFN-γ could stimulate MΦs to limit amastigote replication when it was coupled with lipopolysaccharides but not when it was coupled with tumor necrosis factor alpha. Thus, IFN-γ may play a bidirectional role at the level of parasite-MΦ interactions; when it is optimally coupled with other factors, it has a protective effect against infection, and in the absence of such synergy it promotes amastigote growth. These results reveal a quite unexpected aspect of the L. amazonensis parasite and have important implications for understanding the pathogenesis of the disease and for developing vaccines and immunotherapies.

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Effects of Gamma Interferon, Interleukin-10, and Transforming Growth Factor β on the Survival of Mycobacterium avium subsp. paratuberculosis in Monocyte-Derived Macrophages from Naturally Infected Cattle

Infection and Immunity ◽

10.1128/iai.72.4.1974-1982.2004 ◽

2004 ◽

Vol 72 (4) ◽

pp. 1974-1982 ◽

Cited By ~ 52

Author(s):

M. S. Khalifeh ◽

J. R. Stabel

Keyword(s):

Growth Factor ◽

Cell Cultures ◽

Mycobacterium Avium ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β ◽

Interleukin 10 ◽

Gamma Interferon ◽

Ifn Γ ◽

Culture Supernatants

ABSTRACT Gamma interferon (IFN-γ) plays a significant role in the control of mycobacterial infections, including Mycobacterium avium subsp. paratuberculosis. However, the contribution of other immunoregulatory cytokines, such as interleukin-10 (IL-10) and transforming growth factor β (TGF-β), in Johne's disease has not been investigated as yet. In this study, we examined the effects of in vivo and in vitro infection with M. avium subsp. paratuberculosis on the production of IFN-γ, IL-10, and TGF-β by peripheral blood mononuclear cells (PBMC). We also examined the effects of exogenous IFN-γ, IL-10, and TGF-β on M. avium subsp. paratuberculosis survival in the cell cultures. PBMC obtained from naturally infected cows, regardless of their disease status, specifically upregulated IL-10 and TGF-β in culture supernatants in response to stimulation with live M. avium subsp. paratuberculosis. Nonstimulated PBMC recovered from subclinically infected animals secreted the lowest levels of TGF-β, but after stimulation with live M. avium subsp. paratuberculosis, TGF-β levels in the culture supernatants increased to levels similar to that produced by PBMC from healthy animals. The numbers of viable M. avium subsp. paratuberculosis recovered from cultures from naturally infected animals were higher than those from healthy cows after in vitro infection with M. avium subsp. paratuberculosis. The addition of exogenous IL-10 and TGF-β to PBMC isolated from healthy cows inhibited the bactericidal activity of these cells as evidenced by the increased number of viable M. avium subsp. paratuberculosis recovered from these cultures compared to cell cultures containing medium alone. These data suggest important immune regulatory roles for IL-10 and TGF-β during infection with M. avium subsp. paratuberculosis that may be directly related to their effects on macrophage activation and killing of M. avium subsp. paratuberculosis.

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Differences in Gamma Interferon Production In Vitro Predict the Pace of the In Vivo Response to Leishmania amazonensis in Healthy Volunteers

Infection and Immunity ◽

10.1128/iai.69.12.7453-7460.2001 ◽

2001 ◽

Vol 69 (12) ◽

pp. 7453-7460 ◽

Cited By ~ 37

Author(s):

M. M. L. Pompeu ◽

C. Brodskyn ◽

M. J. Teixeira ◽

J. Clarêncio ◽

J. Van Weyenberg ◽

...

Keyword(s):

Mononuclear Cells ◽

Interleukin 10 ◽

Gamma Interferon ◽

Leishmania Amazonensis ◽

Cell Mediated Immunity ◽

Peripheral Blood Mononuclear ◽

Necrosis Factor Alpha ◽

Ifn Γ

ABSTRACT The initial encounter of Leishmania cells and cells from the immune system is fundamentally important in the outcome of infection and determines disease development or resistance. We evaluated the anti-Leishmania amazonensis response of naive volunteers by using an in vitro priming (IVP) system and comparing the responses following in vivo vaccination against the same parasite. In vitro stimulation allowed us to distinguish two groups of individuals, those who produced small amounts of gamma interferon (IFN-γ) (n = 16) (low producers) and those who produced large amounts of this cytokine (n = 16) (high producers). IFN-γ production was proportional to tumor necrosis factor alpha and interleukin 10 (IL-10) levels but did not correlate with IL-5 production. Volunteers who produced small amounts of IFN-γ in vitro remained low producers 40 days after vaccination, whereas high producers exhibited increased IFN-γ production. However, 6 months after vaccination, all individuals tested produced similarly high levels of IFN-γ upon stimulation of their peripheral blood mononuclear cells with Leishmania promastigotes, indicating that low in vitro producers respond slowly in vivo to vaccination. In high IFN-γ producers there was an increased frequency of activated CD8+ T cells both in vitro and in vivo compared to the frequency in low producers, and such cells were positive for IFN-γ as determined by intracellular staining. Such findings suggest that IVP responses can be used to predict the pace of postvaccination responses of test volunteers. Although all vaccinated individuals eventually have a potent anti-Leishmania cell-mediated immunity (CMI) response, a delay in mounting the CMI response may influence resistance against leishmaniasis.

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Pathology of Plasmodium chabaudi chabaudi Infection and Mortality in Interleukin-10-Deficient Mice Are Ameliorated by Anti-Tumor Necrosis Factor Alpha and Exacerbated by Anti-Transforming Growth Factor β Antibodies

Infection and Immunity ◽

10.1128/iai.71.9.4850-4856.2003 ◽

2003 ◽

Vol 71 (9) ◽

pp. 4850-4856 ◽

Cited By ~ 113

Author(s):

Ching Li ◽

Latifu A. Sanni ◽

Fakhreldin Omer ◽

Eleanor Riley ◽

Jean Langhorne

Keyword(s):

Tumor Necrosis ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β ◽

Interleukin 10 ◽

Plasmodium Chabaudi ◽

Necrosis Factor Alpha ◽

Tnf Α ◽

Factor Alpha ◽

Ifn Γ ◽

Necrosis Factor

ABSTRACT Interleukin-10 (IL-10)-deficient (IL-10−/−) mice infected with Plasmodium chabaudi (AS) suffer a more severe disease and exhibit a higher rate of mortality than control C57BL/6 mice. Here, we show that a drop in body temperature to below 28°C and pronounced hypoglycemia of below 3 mM are reliable indicators of a lethal infection. Elevated inflammatory responses have been shown to accompany pathology in infected IL-10−/− mice. We show that neutralization of tumor necrosis factor alpha (TNF-α) in IL-10−/− mice abolishes mortality and ameliorates the hypothermia, weight loss, and anemia but does not affect the degree of hypoglycemia. These data suggest that TNF-α is involved in some of the pathology associated with a P. chabaudi infection in IL-10−/− mice but other factors play a role. IL-10−/− mice that survive a primary infection have been shown to control gamma interferon (IFN-γ) and TNF-α production, indicating that other cytokines or mechanisms may be involved in their down-regulation. Significantly higher levels of transforming growth factor β (TGF-β), a cytokine with such properties, are present in the plasma of infected IL-10−/− mice at a time that coincides with the disappearance of IFN-γ and TNF-α from the blood. Neutralization of TGF-β in IL-10−/− mice resulted in higher circulating amounts of TNF-α and IFN-γ, and all treated IL-10−/− mice died within 12 days with increased pathology but with no obvious increase in parasitemia. Our data suggest that a tight regulation of the balance between regulatory cytokines such as IL-10 and TGF-β and inflammatory cytokines such as IFN-γ and TNF-α is critical for survival in a mouse malaria infection.

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Extracellular Vesicles from Cryptococcus neoformans Modulate Macrophage Functions

Infection and Immunity ◽

10.1128/iai.01171-09 ◽

2010 ◽

Vol 78 (4) ◽

pp. 1601-1609 ◽

Cited By ~ 131

Author(s):

Débora L. Oliveira ◽

Célio G. Freire-de-Lima ◽

Joshua D. Nosanchuk ◽

Arturo Casadevall ◽

Marcio L. Rodrigues ◽

...

Keyword(s):

Cryptococcus Neoformans ◽

Extracellular Vesicles ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β ◽

Interleukin 10 ◽

Biologically Active ◽

Host Cells ◽

Phagocytic Cells ◽

Necrosis Factor Alpha

ABSTRACT Cryptococcus neoformans and distantly related fungal species release extracellular vesicles that traverse the cell wall and contain a varied assortment of components, some of which have been associated with virulence. Previous studies have suggested that these extracellular vesicles are produced in vitro and during animal infection, but the role of vesicular secretion during the interaction of fungi with host cells remains unknown. In this report, we demonstrate by fluorescence microscopy that mammalian macrophages can incorporate extracellular vesicles produced by C. neoformans. Incubation of cryptococcal vesicles with murine macrophages resulted in increased levels of extracellular tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10), and transforming growth factor β (TGF-β). Vesicle preparations also resulted in a dose-dependent stimulation of nitric oxide production by phagocytes, suggesting that vesicle components stimulate macrophages to produce antimicrobial compounds. Treated macrophages were more effective at killing C. neoformans yeast. Our results indicate that the extracellular vesicles of C. neoformans can stimulate macrophage function, apparently activating these phagocytic cells to enhance their antimicrobial activity. These results establish that cryptococcal vesicles are biologically active.

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Interleukin-4 and Transforming Growth Factor β Have Opposing Regulatory Effects on Gamma Interferon-Mediated Inhibition of Cryptosporidium parvum Reproduction

Infection and Immunity ◽

10.1128/iai.71.8.4580-4585.2003 ◽

2003 ◽

Vol 71 (8) ◽

pp. 4580-4585 ◽

Cited By ~ 28

Author(s):

I.-Sarah Lean ◽

Stuart A. C. McDonald ◽

Mona Bajaj-Elliott ◽

Richard C. G. Pollok ◽

Michael J. G. Farthing ◽

...

Keyword(s):

Growth Factor ◽

Cryptosporidium Parvum ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β ◽

Inhibitory Effect ◽

Gamma Interferon ◽

Interleukin 4 ◽

Effector Cells ◽

Ifn Γ

ABSTRACT It was shown previously that enterocytes activated by gamma interferon (IFN-γ) are efficient effector cells in the killing of Cryptosporidium parvum. How this function is regulated is not clearly understood, but transforming growth factor β (TGF-β) and the Th2 regulatory cytokines may play a role. Using an in vitro cell culture system, we investigated how the key regulatory cytokines interleukin-4 (IL-4), IL-10, IL-13, and TGF-β might modulate the effect of IFN-γ in inducing resistance to infection in enterocyte cell lines. The results showed that TGF-β can abolish the inhibitory effect on C. parvum development and that neither IL-13 nor IL-10 influenced the action of IFN-γ. In contrast, IL-4 cooperated with low concentrations of IFN-γ (1 and 10 U/ml) to enhance parasite killing. One mechanism that appeared to be involved in the combined activity of IFN-γ and IL-4 was intracellular Fe2+ deprivation, but induction of nitric oxide production was not involved. In one cell line, the extents and durations of phosphorylation of STAT1, a transcription factor involved in IFN-γ signaling, were similar when cells were stimulated with IFN-γ alone and with IFN-γ and IL-4γ, suggesting that the cooperative effect of the cytokines was not related to STAT1 activation. The effects of the presence of TGF-β and IL-4 on IFN-γ function did not appear to involve any alteration in the level of expression of IFN-γ receptors.

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Helicobacter hepaticus Triggers Colitis in Specific-Pathogen-Free Interleukin-10 (IL-10)-Deficient Mice through an IL-12- and Gamma Interferon-Dependent Mechanism

Infection and Immunity ◽

10.1128/iai.66.11.5157-5166.1998 ◽

1998 ◽

Vol 66 (11) ◽

pp. 5157-5166 ◽

Cited By ~ 289

Author(s):

Marika C. Kullberg ◽

Jerrold M. Ward ◽

Peter L. Gorelick ◽

Patricia Caspar ◽

Sara Hieny ◽

...

Keyword(s):

Intestinal Inflammation ◽

Intestinal Flora ◽

Interleukin 10 ◽

Gamma Interferon ◽

Helicobacter Hepaticus ◽

Specific Pathogen Free ◽

Necrosis Factor Alpha ◽

Bacterial Agent ◽

Specific Pathogen ◽

Ifn Γ

ABSTRACT Mice rendered deficient in interleukin-10 (IL-10) by gene targeting (IL-10−/− mice) develop chronic enterocolitis resembling human inflammatory bowel disease (IBD) when maintained in conventional animal facilities. However, they display a minimal and delayed intestinal inflammatory response when reared under specific-pathogen-free (SPF) conditions, suggesting the involvement of a microbial component in pathogenesis. We show here that experimental infection with a single bacterial agent, Helicobacter hepaticus, induces chronic colitis in SPF-reared IL-10−/− mice and that the disease is accompanied by a type 1 cytokine response (gamma interferon [IFN-γ], tumor necrosis factor alpha, and nitric oxide) detected by restimulation of spleen and mesenteric lymph node cells with a soluble H. hepaticusantigen (Ag) preparation. In contrast, wild-type (WT) animals infected with the same bacteria did not develop disease and produced IL-10 as the dominant cytokine in response to Helicobacter Ag. Strong H. hepaticus-reactive antibody responses as measured by Ag-specific total immunoglobulin G (IgG), IgG1, IgG2a, IgG2b, IgG3, and IgA were observed in both WT and IL-10−/− mice. In vivo neutralization of IFN-γ or IL-12 resulted in a significant reduction of intestinal inflammation in H. hepaticus-infected IL-10−/− mice, suggesting an important role for these cytokines in the development of colitis in the model. Taken together, these microbial reconstitution experiments formally establish that a defined bacterial agent can serve as the immunological target in the development of large bowel inflammation in IL-10−/− mice and argue that in nonimmunocompromised hosts IL-10 stimulated in response to intestinal flora is important in preventing IBD.

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Suppressed Type 1, Type 2, and Type 17 Cytokine Responses in Active Tuberculosis in Children

Clinical and Vaccine Immunology ◽

10.1128/cvi.05366-11 ◽

2011 ◽

Vol 18 (11) ◽

pp. 1856-1864 ◽

Cited By ~ 18

Author(s):

N. Pavan Kumar ◽

R. Anuradha ◽

R. Suresh ◽

R. Ganesh ◽

Janani Shankar ◽

...

Keyword(s):

Transforming Growth Factor ◽

Transforming Growth Factor Β ◽

Interleukin 4 ◽

Mycobacterial Antigen ◽

Necrosis Factor Alpha ◽

Cytokine Responses ◽

Pediatric Tb ◽

Ifn Γ ◽

Pediatric Tuberculosis

ABSTRACTType 1 cytokine responses are known to play an important role in immunity to tuberculosis (TB) in children, although little is known about other factors that might be important. In addition, children are more prone to developing extrapulmonary manifestations of TB than adults. To identify the immune responses important both in control of infection and in extrapulmonary dissemination, we examined mycobacterium-specific cytokine responses of children with pulmonary TB (PTB) and extrapulmonary TB (ETB) and compared them with those of healthy control children (HC). No significant differences were found in the cytokine responses either with no stimulation or following mycobacterial-antigen (Ag) stimulation between children with PTB and ETB. On the other hand, children with active TB compared with HC showed markedly diminished production of type 1 (gamma interferon [IFN-γ] and tumor necrosis factor alpha [TNF-α]), 2 (interleukin 4 [IL-4] and IL-13), and 17 (IL-17A, IL-21, and IL-23)-associated cytokines with no stimulation and in response to mycobacterial antigens. This was not associated with significantly altered production of IL-10 or transforming growth factor β (TGF-β). Among children with ETB, those with neurologic involvement exhibited more significantly diminished Ag-driven IFN-γ and IL-17 production. Pediatric TB is characterized by diminished type 1, 2, and 17 cytokine responses, with the most profound diminution favoring development of neurologic TB, suggesting a crucial role for these cytokines in protection against pediatric tuberculosis.

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Down-Modulation of Lung Immune Responses by Interleukin-10 and Transforming Growth Factor β (TGF-β) and Analysis of TGF-β Receptors I and II in Active Tuberculosis

Infection and Immunity ◽

10.1128/iai.72.5.2628-2634.2004 ◽

2004 ◽

Vol 72 (5) ◽

pp. 2628-2634 ◽

Cited By ~ 91

Author(s):

M. Glória Bonecini-Almeida ◽

John L. Ho ◽

Neio Boéchat ◽

Richard C. Huard ◽

Sadhana Chitale ◽

...

Keyword(s):

Growth Factor ◽

Cellular Response ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β ◽

Interleukin 10 ◽

Active Tuberculosis ◽

Alveolar Cells ◽

Old Patients ◽

Protein Levels ◽

Ifn Γ

ABSTRACT Immune factors influencing progression to active tuberculosis (TB) remain poorly defined. In this study, we investigated the expression of immunoregulatory cytokines and receptors by using lung bronchoalveolar lavage cells obtained from patients with pulmonary TB, patients with other lung diseases (OLD patients), and healthy volunteers (VOL) by using reverse transcriptase PCR, a transforming growth factor β (TGF-β) bioactivity assay, and an enzyme immunoassay. TB patients were significantly more likely than OLD patients to coexpress TGF-β receptor I (RI) and RII mRNA, as well as interleukin-10 (IL-10) mRNA (thereby indicating the state of active gene transcription in the alveolar cells at harvest). In contrast, gamma interferon (IFN-γ) and IL-2 mRNA was seen in both TB and OLD patients. Likewise, significantly elevated pulmonary steady-state protein levels of IL-10, IFN-γ, and bioactive TGF-β were found in TB patients versus those in OLD patients and VOL. These data suggest that the combined production of the immunosuppressants IL-10 and TGF-β, as well as coexpression of TGF-β RI and RII (required for cellular response to TGF-β), may act to down-modulate host anti-Mycobacterium tuberculosis immunity and thereby allow uncontrolled bacterial replication and overt disease. Delineating the underlying mechanisms of M. tuberculosis-triggered expression of these immune elements may provide a molecular-level understanding of TB immunopathogenesis.

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Antagonizing Deactivating Cytokines To Enhance Host Defense and Chemotherapy in Experimental Visceral Leishmaniasis

Infection and Immunity ◽

10.1128/iai.73.7.3903-3911.2005 ◽

2005 ◽

Vol 73 (7) ◽

pp. 3903-3911 ◽

Cited By ~ 46

Author(s):

Henry W. Murray ◽

Kathleen C. Flanders ◽

Debra D. Donaldson ◽

Joseph P. Sypek ◽

Philip J. Gotwals ◽

...

Keyword(s):

Visceral Leishmaniasis ◽

Leishmania Donovani ◽

Transforming Growth Factor ◽

Therapeutic Potential ◽

Transforming Growth Factor Β ◽

Interleukin 10 ◽

Th1 Cell ◽

Pentavalent Antimony ◽

Ifn Γ ◽

Liver Infection

ABSTRACT In experimental visceral leishmaniasis, inhibition of interleukin 10 (IL-10) signaling enhances Th1-cell-associated responses, promoting gamma interferon (IFN-γ) secretion, granuloma assembly, macrophage activation with substantial liver parasite killing, and synergy with pentavalent antimony (Sb) chemotherapy. To determine if inhibiting other suppressive cytokines has similar therapeutic potential, Leishmania donovani-infected BALB/c mice were injected with anti-IL-4 monoclonal antibody or receptor fusion antagonists of IL-13 or transforming growth factor β (TGF-β). Targeting IL-13 or TGF-β enabled inhibition of L. donovani replication but little parasite killing; anti-IL-4 had no effect. None of the three antagonists promoted IFN-γ production, granuloma maturation, or Sb efficacy. Excess IL-13 and TGF-β exacerbated liver infection; however, effects were transient. Among IL-10, IL-4, IL-13, and TGF-β, cytokines capable of disabling Th1-cell mechanisms (including those which support chemotherapy), IL-10 appears to be the appropriate target for therapeutic inhibition in visceral L. donovani infection.

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Low-Dose Intradermal Infection with Trypanosoma congolense Leads to Expansion of Regulatory T Cells and Enhanced Susceptibility to Reinfection

Infection and Immunity ◽

10.1128/iai.01028-13 ◽

2013 ◽

Vol 82 (3) ◽

pp. 1074-1083 ◽

Cited By ~ 12

Author(s):

Chukwunonso Onyilagha ◽

Ifeoma Okwor ◽

Shiby Kuriakose ◽

Rani Singh ◽

Jude Uzonna

Keyword(s):

Low Dose ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β ◽

Interleukin 10 ◽

Trypanosoma Congolense ◽

Challenge Infection ◽

Rapid Expansion ◽

Necrosis Factor Alpha ◽

Content Type ◽

Treg Depletion

ABSTRACTBALB/c mice are highly susceptible to experimental intraperitonealTrypanosoma congolenseinfection. However, a recent report showed that these mice are relatively resistant to primary intradermal low-dose infection. Paradoxically, repeated low-dose intradermal infections predispose mice to enhanced susceptibility to an otherwise noninfectious dose challenge. Here, we explored the mechanisms responsible for this low-dose-induced susceptibility to subsequent low-dose challenge infection. We found that akin to intraperitoneal infection, low-dose intradermal infection led to production of interleukin-10 (IL-10), IL-6, IL-12, tumor necrosis factor alpha (TNF-α), transforming growth factor β (TGF-β), and gamma interferon (IFN-γ) by spleen and draining lymph node cells. Interestingly, despite the absence of parasitemia, low-dose intradermal infection led to expansion of CD4+CD25+Foxp3+cells (T regulatory cells [Tregs]) in both the spleens and lymph nodes draining the infection site. Depletion of Tregs by anti-CD25 monoclonal antibody (MAb) treatment during primary infection or before challenge infection following repeated low-dose infection completely abolished the low-dose-induced enhanced susceptibility. In addition, Treg depletion was associated with dramatic reduction in serum levels of TGF-β and IL-10. Collectively, these findings show that low-dose intradermal infection leads to rapid expansion of Tregs, and these cells mediate enhanced susceptibility to subsequent infection.

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