MGL1 Receptor Plays a Key Role in the Control of T. cruzi Infection by Increasing Macrophage Activation through Modulation of ERK1/2, c-Jun, NF-κB and NLRP3 Pathways

Macrophage galactose-C type lectin (MGL)1 receptor is involved in the recognition of Trypanosoma cruzi (T. cruzi) parasites and is important for the modulation of the innate and adaptive immune responses. However, the mechanism by which MGL1 promotes resistance to T. cruzi remains unclear. Here, we show that MGL1 knockout macrophages (MGL1−/− Mφ) infected in vitro with T. cruzi were heavily parasitized and showed decreased levels of reactive oxygen species (ROS), nitric oxide (NO), IL-12 and TNF-α compared to wild-type macrophages (WT Mφ). MGL1−/− Mφ stimulated in vitro with T. cruzi antigen (TcAg) showed low expression of TLR-2, TLR-4 and MHC-II, which resulted in deficient splenic cell activation compared with similar co-cultured WT Mφ. Importantly, the activation of p-ERK1/2, p-c-Jun and p-NF-κB p65 were significantly reduced in MGL1−/− Mφ exposed to TcAg. Similarly, procaspase 1, caspase 1 and NLRP3 inflammasome also displayed a reduced expression that was associated with low IL-β production. Our data reveal a previously unappreciated role for MGL1 in Mφ activation through the modulation of ERK1/2, c-Jun, NF-κB and NLRP3 signaling pathways, and to the development of protective innate immunity against experimental T. cruzi infection.

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In Vitro Platform Establishes Antigen-Specific CD8+ T Cell Cytotoxicity to Encapsulated Cells via Indirect Antigen Recognition

10.1101/2019.12.11.872978 ◽

2019 ◽

Author(s):

Ying Li ◽

Anthony W. Frei ◽

Ethan Y. Yang ◽

Irayme Labrada-Miravet ◽

Chuqiao Sun ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

T Cell Activation ◽

Cell Activation ◽

Immune Recognition ◽

Adaptive Immune Responses ◽

Activated T Cells ◽

Encapsulated Cells ◽

Adaptive Immune

AbstractCell replacement therapy has the potential to cure diseases caused by the absence or malfunction of specialized cells. A substantial impediment to the success of any non-autologous cellular transplant is the need for systemic immunosuppressive drugs to prevent host-mediated rejection of the foreign cells. Cellular encapsulation, i.e., the entrapment of cells within stable polymeric hydrogels, has been clinically explored to prevent host immune recognition and attack, but the efficacy of these encapsulated grafts is poor. While several studies have explored improvements in innate immune acceptance of these encapsulated cells, little attention has been paid to the roles of adaptive immune responses, specifically graft-targeting T cell activation, in graft destabilization. Herein, we established an efficient, single-antigen in vitro platform capable of delineating direct and indirect host T cell recognition to microencapsulated cellular grafts and evaluating their consequential impacts. Using alginate as the model hydrogel, encapsulated membrane-bound ovalbumin (mOVA) stimulator cells were incubated with antigen-specific OTI lymphocytes and subsequent OVA-specific CD8+ T cell activation and effector function were quantified. We established that alginate microencapsulation abrogates direct T cell activation by interrupting donor-host interaction; however, indirect T cell activation mediated by host antigen presenting cells (APCs) primed with shed donor antigens still occurs. These activated T cells imparted cytotoxicity on the encapsulated cells, likely via diffusion of cytotoxic solutes. Overall, this platform delivers unique mechanistic insight into the impacts of hydrogel encapsulation on host adaptive immune responses, as well as a tool for the efficient immune screening on new encapsulation methods and/or synergistic immunomodulatory agents.

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Enhanced Dendritic Cell Maturation by TNF-α or Cytidine-Phosphate-Guanosine DNA Drives T Cell Activation In Vitro and Therapeutic Anti-Tumor Immune Responses In Vivo

The Journal of Immunology ◽

10.4049/jimmunol.165.11.6278 ◽

2000 ◽

Vol 165 (11) ◽

pp. 6278-6286 ◽

Cited By ~ 107

Author(s):

Christoph Brunner ◽

Julia Seiderer ◽

Angelika Schlamp ◽

Martin Bidlingmaier ◽

Andreas Eigler ◽

...

Keyword(s):

T Cell ◽

Dendritic Cell ◽

Immune Responses ◽

T Cell Activation ◽

Cell Activation ◽

Dendritic Cell Maturation ◽

Cell Maturation ◽

Tnf Α

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Undaria pinnatifida Fucoidan-Rich Extract Induces Both Innate and Adaptive Immune Responses

Natural Product Communications ◽

10.1177/1934578x19873724 ◽

2019 ◽

Vol 14 (8) ◽

pp. 1934578X1987372

Author(s):

Hwan H. Lee ◽

Yoo J. Cho ◽

Daeung Yu ◽

Donghwa Chung ◽

Gun-Hee Kim ◽

...

Keyword(s):

Immune Responses ◽

Cd8 T Cells ◽

Undaria Pinnatifida ◽

Plasma Concentrations ◽

Adaptive Immune Responses ◽

Adaptive Immune ◽

Tnf Α ◽

Ifn Γ

Fucoidans are widely used as an ingredient of dietary supplements. We investigated the immune stimulatory activities of Undaria pinnatifida ( Alariaceae) fucoidan-rich extract (UPF-RE) in vitro as well as in vivo . In vitro, the extract stimulated Raw 264.7 cells to produce significant nitric oxide (NO) metabolites and cytokines (TNF-α, IL-1α, IL-1β, and IL-6). It also induced the proliferation of primary mouse splenocytes and the secretion of IL-4, which correlated with the phosphorylation of Extracellular-signal-regulated kinase (ERK) protein. In in vivo experiments, first, 50 mg/kg of 3 different types of UPF-RE, DSU02, DSU02L (low molecular weight, <3 kDa), and DSU02H (high molecular weight, >10 kDa), were orally administered to C57BL/6 mice. After 14 days, the frequencies of CD3+, CD4+, and CD8+ T cells and NK cells from each group were analyzed. Plasma concentrations of TNF-α and IFN-γ were determined. The frequencies of CD3+ and CD4+ showed a statistically significant increase in splenocytes isolated from the DSU02 and DSU02H groups. Also, there was significant production of TNF-α and IFN-γ from the DSU02 group. Second, 3 different concentrations of DSU02 (50, 100, and 150 mg/kg) were orally administered. After 14 days, the proliferative capacity of CD3+, CD4+, and CD8+ T cells was investigated, and the plasma concentrations of IgM and total IgG were determined. Plasma concentration of IgM from the DSU02 150 mg/kg group was statistically significantly higher compared with that from the other groups. We suggest that UPF-RE could be a good candidate for a natural immune stimulator to induce innate as well as adaptive immune responses.

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Engineered SIRPα Variants as Immunotherapeutic Adjuvants to Anticancer Antibodies

Science ◽

10.1126/science.1238856 ◽

2013 ◽

Vol 341 (6141) ◽

pp. 88-91 ◽

Cited By ~ 222

Author(s):

Kipp Weiskopf ◽

Aaron M. Ring ◽

Chia Chi M. Ho ◽

Jens-Peter Volkmer ◽

Aron M. Levin ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Immune Responses ◽

Cancer Cells ◽

Macrophage Activation ◽

Universal Method ◽

Wild Type ◽

High Affinity ◽

Macrophage Phagocytosis

CD47 is an antiphagocytic signal that cancer cells employ to inhibit macrophage-mediated destruction. Here, we modified the binding domain of human SIRPα, the receptor for CD47, for use as a CD47 antagonist. We engineered high-affinity SIRPα variants with about a 50,000-fold increased affinity for human CD47 relative to wild-type SIRPα. As high-affinity SIRPα monomers, they potently antagonized CD47 on cancer cells but did not induce macrophage phagocytosis on their own. Instead, they exhibited remarkable synergy with all tumor-specific monoclonal antibodies tested by increasing phagocytosis in vitro and enhancing antitumor responses in vivo. This “one-two punch” directs immune responses against tumor cells while lowering the threshold for macrophage activation, thereby providing a universal method for augmenting the efficacy of therapeutic anticancer antibodies.

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Viable Borrelia burgdorferi Enhances Interleukin-10 Production and Suppresses Activation of Murine Macrophages

Infection and Immunity ◽

10.1128/iai.01404-07 ◽

2007 ◽

Vol 76 (3) ◽

pp. 1153-1162 ◽

Cited By ~ 34

Author(s):

John J. Lazarus ◽

Maria A. Kay ◽

Akisha L. McCarter ◽

R. Mark Wooten

Keyword(s):

Borrelia Burgdorferi ◽

Immune Responses ◽

Culture Medium ◽

Interleukin 10 ◽

Innate Immune ◽

Innate Immune Responses ◽

Wild Type ◽

Adaptive Immune

ABSTRACT Although it is capable of eliciting strong innate and adaptive immune responses, Borrelia burgdorferi often evades immune clearance through largely unknown mechanisms. Our previous studies determined that infected interlukin-10−/− (IL-10−/−) mice show significantly lower B. burgdorferi levels than wild-type (B6) mice and that IL-10 inhibits innate immune responses critical for controlling B. burgdorferi infection. To determine whether virulent B. burgdorferi preferentially enhances IL-10 production, we developed an in vitro coculture medium (RPMI.B) in which both B. burgdorferi and primary macrophages (Mφs) remain viable. B. burgdorferi grew at similar rates and was able to regulate expression of immunoreactive proteins with similar kinetics in RPMI.B and in traditional BSK medium; in contrast, B. burgdorferi cultured in conventional tissue culture medium (RPMI) rapidly lost viability. Coculture of viable B. burgdorferi in RPMI.B with Mφs resulted in more rapid and significant increases in IL-10 transcripts and secreted proteins than coculture with nonviable B. burgdorferi in RPMI, which corresponded with decreased production of proinflammatory cytokines. Addition of live B. burgdorferi to Mφs in RPMI.B also elicited substantially higher IL-10 levels than heat-killed bacteria elicited, confirming that increased IL-10 production was not inherent to coculture in RPMI.B. Transfer of supernatants from B. burgdorferi-stimulated Mφs into naïve Mφ cultures resulted in suppressed activation upon subsequent stimulation with different bacterial agonists, and this suppression was obviated by IL-10-specific antibody. In vivo analyses determined that murine skin samples exhibited substantial upregulation of IL-10 within 24 h of injection of B. burgdorferi. Together, these results suggest that viable B. burgdorferi can suppress early Mφ responses during infection by causing increased release of IL-10.

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Human Endothelial Cells Enhance Human Immunodeficiency Virus Type 1 Replication in CD4+ T Cells in a Nef-Dependent Manner In Vitro and In Vivo

Journal of Virology ◽

10.1128/jvi.79.1.264-276.2005 ◽

2005 ◽

Vol 79 (1) ◽

pp. 264-276 ◽

Cited By ~ 20

Author(s):

Jaehyuk Choi ◽

Jason Walker ◽

Sergei Boichuk ◽

Nancy Kirkiles-Smith ◽

Nicholas Torpey ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

Dependent Manner ◽

Wild Type ◽

Mhc Ii ◽

Hiv 1

ABSTRACT Infected CD4+ T cells are the primary sites of human immunodeficiency virus type 1 (HIV-1) replication in vivo. However, signals from professional antigen-presenting cells (APCs), such as dendritic cells and macrophages, greatly enhance HIV-1 replication in T cells. Here, we report that in cocultures, vascular endothelial cells (ECs), which in humans can also serve as APCs, can enhance HIV-1 production of both CCR5- and CXCR4-utilizing strains approximately 50,000-fold. The observed HIV-1 replication enhancement conferred by ECs occurred only in memory CD4+ T cells, required expression of major histocompatibility complex class II (MHC-II) molecules by the ECs, and could not be conferred by fixed ECs, all of which are consistent with a requirement for EC-mediated T-cell activation via T-cell receptor (TCR) signaling. Deletion of nef (Nef−) decreased HIV-1 production by approximately 100-fold in T cells cocultured with ECs but had no effect on virus production in T cells cocultured with professional APCs or fibroblasts induced to express MHC-II. Human ECs do not express B7 costimulators, but Nef− replication in CD4+-T-cell and EC cocultures could not be rescued by anti-CD28 antibody. ECs act in trans to enhance wild-type but not Nef− replication and facilitate enhanced wild-type replication in naïve T cells when added to T-cell or B-lymphoblastoid cell cocultures, suggesting that ECs also provide a TCR-independent signal to infected T cells. Consistent with these in vitro observations, wild-type HIV-1 replicated 30- to 50-fold more than Nef− in human T cells infiltrating allogeneic human skin grafts on human huPBL-SCID/bg mice, an in vivo model of T-cell activation by ECs. Our studies suggest that ECs, which line the entire cardiovascular system and are, per force, in frequent contact with memory CD4+ T cells, provide signals to HIV-1-infected CD4+ T cells to greatly enhance HIV-1 production in a Nef-dependent manner, a mechanism that could contribute to the development of AIDS.

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Immunocompetence of macrophages in rats exposed toCandida albicansinfection and stress

AJP Cell Physiology ◽

10.1152/ajpcell.00160.2002 ◽

2003 ◽

Vol 284 (1) ◽

pp. C111-C118 ◽

Cited By ~ 13

Author(s):

Maria Cecilia Rodriguez-Galán ◽

Claudia Sotomayor ◽

Maria Eugenia Costamagna ◽

Ana Maria Cabanillas ◽

Beatriz Salido Renterı́a ◽

...

Keyword(s):

Immune Responses ◽

Stress Exposure ◽

Adaptive Immune ◽

Local Site ◽

Colony Forming Units ◽

Tnf Α ◽

Efficient Control ◽

Factor Α ◽

Necrosis Factor

The integration of innate and adaptive immune responses is required for efficient control of Candida albicans. The present work aimed to assess, at the local site of the infection, the immunocompetence of macrophages in rats infected intraperitoneally with C. albicans and exposed simultaneously to stress during 3 days (CaS group). We studied the 1) ability to remove and kill C. albicans, 2) tumor necrosis factor-α (TNF-α) release, 3) balance of the inducible enzymes NO synthase (iNOS) and arginase, and 4) expression of interleukin (IL)-1β and IL-1 receptor antagonist (ra) mRNA. Compared with only infected animals (Ca group), the number of colony-forming units was significantly higher in CaS rats ( P < 0.01), and the macrophage candidicidal activity was ∼2.5-fold lower ( P < 0.01). Release of TNF-α was diminished in both unstimulated and heat-killed C. albicans restimulated macrophages of the CaS group (Ca vs. CaS, P < 0.03 and P < 0.05, respectively). In Ca- and CaS-group rats, the rates for both the arginase activity and the NO synthesis were significantly enhanced. However, the stress exposure downregulated the activity of both enzymes (CaS vs. Ca, P < 0.05). After in vitro restimulation, the IL-1ra/IL-1β ratio was significantly diminished in CaS-group rats ( P < 0.05). Our results indicate that a correlation exists between early impairment of macrophage function and stress exposure.

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Neutrophil subtypes shape HIV-specific CD8 T-cell responses after vaccinia virus infection

npj Vaccines ◽

10.1038/s41541-021-00314-7 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Mauro Di Pilato ◽

Miguel Palomino-Segura ◽

Ernesto Mejías-Pérez ◽

Carmen E. Gómez ◽

Andrea Rubio-Ponce ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

Vaccinia Virus ◽

Adaptive Immune System ◽

T Cell Responses ◽

Cd8 T Cell ◽

Cell Responses ◽

Adaptive Immune

AbstractNeutrophils are innate immune cells involved in the elimination of pathogens and can also induce adaptive immune responses. Nα and Nβ neutrophils have been described with distinct in vitro capacity to generate antigen-specific CD8 T-cell responses. However, how these cell types exert their role in vivo and how manipulation of Nβ/Nα ratio influences vaccine-mediated immune responses are not known. In this study, we find that these neutrophil subtypes show distinct migratory and motility patterns and different ability to interact with CD8 T cells in the spleen following vaccinia virus (VACV) infection. Moreover, after analysis of adhesion, inflammatory, and migration markers, we observe that Nβ neutrophils overexpress the α4β1 integrin compared to Nα. Finally, by inhibiting α4β1 integrin, we increase the Nβ/Nα ratio and enhance CD8 T-cell responses to HIV VACV-delivered antigens. These findings provide significant advancements in the comprehension of neutrophil-based control of adaptive immune system and their relevance in vaccine design.

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A role for CD9 molecules in T cell activation.

Journal of Experimental Medicine ◽

10.1084/jem.184.2.753 ◽

1996 ◽

Vol 184 (2) ◽

pp. 753-758 ◽

Cited By ~ 63

Author(s):

X G Tai ◽

Y Yashiro ◽

R Abe ◽

K Toyooka ◽

C R Wood ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Immune Responses ◽

T Cell Activation ◽

Cell Activation ◽

Expression Cloning ◽

Wild Type ◽

Almost All ◽

Antigen Presenting ◽

Deficient Mice

Costimulation mediated by the CD28 molecule plays an important role in optimal activation of T cells. However, CD28-deficient mice can mount effective T cell-dependent immune responses, suggesting the existence of other costimulatory systems. In a search for other costimulatory molecules on T cells, we have developed a monoclonal antibody (mAb) that can costimulate T cells in the absence of antigen-presenting cells (APC). The molecule recognized by this mAb, 9D3, was found to be expressed on almost all mature T cells and to be a protein of approximately 24 kD molecular mass. By expression cloning, this molecule was identified as CD9, 9D3 (anti-CD9) synergized with suboptimal doses of anti-CD3 mAb in inducing proliferation by virgin T cells. Costimulation was induced by independent ligation of CD3 and CD9, suggesting that colocalization of these two molecules is not required for T cell activation. The costimulation by anti-CD9 was as potent as that by anti-CD28. Moreover, anti-CD9 costimulated in a CD28-independent way because anti-CD9 equally costimulated T cells from the CD28-deficient as well as wild-type mice. Thus, these results indicate that CD9 serves as a molecule on T cells that can deliver a potent CD28-independent costimulatory signal.

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