scholarly journals Granulysin activates antigen-presenting cells through TLR4 and acts as an immune alarmin

Blood ◽  
2010 ◽  
Vol 116 (18) ◽  
pp. 3465-3474 ◽  
Author(s):  
Poonam Tewary ◽  
De Yang ◽  
Gonzalo de la Rosa ◽  
Yana Li ◽  
Michael W. Finn ◽  
...  

Abstract Granulysin (GNLY), an antimicrobial protein present in the granules of human cytotoxic T lymphocytes and natural killer (NK) cells, is produced as an intact 15-kDa form that is cleaved to yield a 9-kDa form. Alarmins are endogenous mediators that can induce recruitment and activation of antigen-presenting cells (APCs) and consequently promote the generation of immune response. We hypothesized that GNLY might function as an alarmin. Here, we report that both 9- and 15-kDa forms of recombinant GNLY-induced in vitro chemotaxis and activation of both human and mouse dendritic cells (DCs), recruited inflammatory leucocytes, including APCs in mice, and promoted antigen-specific immune responses upon coadministration with an antigen. GNLY-induced APC recruitment and activation required the presence of Toll-like receptor 4. The observed activity of recombinant GNLY was not due to endotoxin contamination. The capability of the supernatant of GNLY-expressing HuT78 cells to activate DC was blocked by anti-GNLY antibodies. Finally we present evidence that supernatants of degranulated human NK92 or primary NK cells also activated DCs in a GNLY- and Toll-like receptor 4–dependent manner, indicating the physiologic relevance of our findings. Thus, GNLY is the first identified lymphocyte-derived alarmin capable of promoting APC recruitment, activation, and antigen-specific immune response.

2016 ◽  
Vol 84 (7) ◽  
pp. 1986-1993 ◽  
Author(s):  
Shigeki Nakamura ◽  
Naoki Iwanaga ◽  
Masafumi Seki ◽  
Kenji Fukudome ◽  
Kazuhiro Oshima ◽  
...  

Chronic lower respiratory tract infection withPseudomonas aeruginosais difficult to treat due to enhanced antibiotic resistance and decreased efficacy of drug delivery to destroyed lung tissue. To determine the potential for restorative immunomodulation therapies, we evaluated the effect of Toll-like receptor 4 (TLR4) stimulation on the host immune response toPseudomonasinfection in mice. We implanted sterile plastic tubes precoated withP. aeruginosain the bronchi of mice, administered the TLR4/MD2 agonistic monoclonal antibody UT12 intraperitoneally every week, and subsequently analyzed the numbers of viable bacteria and inflammatory cells and the levels of cytokines. We also performed flow cytometry-based phagocytosis and opsonophagocytic killing assaysin vitrousing UT12-treated murine peritoneal neutrophils. UT12-treated mice showed significantly enhanced bacterial clearance, increased numbers of Ly6G+neutrophils, and increased concentrations of macrophage inflammatory protein 2 (MIP-2) in the lungs (P< 0.05). Depletion of CD4+T cells eliminated the ability of the UT12 treatment to improve bacterial clearance and promote neutrophil recruitment and MIP-2 production. Additionally, UT12-pretreated peritoneal neutrophils exhibited increased opsonophagocytic killing activity via activation of the serine protease pathway, specifically neutrophil elastase activity, in a TLR4-dependent manner. These data indicated that UT12 administration significantly augmented the innate immune response against chronic bacterial infection, in part by promoting neutrophil recruitment and bactericidal function.


2020 ◽  
Vol 117 (44) ◽  
pp. 27528-27539
Author(s):  
Alsya J. Affandi ◽  
Joanna Grabowska ◽  
Katarzyna Olesek ◽  
Miguel Lopez Venegas ◽  
Arnaud Barbaria ◽  
...  

Priming of CD8+T cells by dendritic cells (DCs) is crucial for the generation of effective antitumor immune responses. Here, we describe a liposomal vaccine carrier that delivers tumor antigens to human CD169/Siglec-1+antigen-presenting cells using gangliosides as targeting ligands. Ganglioside-liposomes specifically bound to CD169 and were internalized by in vitro-generated monocyte-derived DCs (moDCs) and macrophages and by ex vivo-isolated splenic macrophages in a CD169-dependent manner. In blood, high-dimensional reduction analysis revealed that ganglioside-liposomes specifically targeted CD14+CD169+monocytes and Axl+CD169+DCs. Liposomal codelivery of tumor antigen and Toll-like receptor ligand to CD169+moDCs and Axl+CD169+DCs led to cytokine production and robust cross-presentation and activation of tumor antigen-specific CD8+T cells. Finally, Axl+CD169+DCs were present in cancer patients and efficiently captured ganglioside-liposomes. Our findings demonstrate a nanovaccine platform targeting CD169+DCs to drive antitumor T cell responses.


2001 ◽  
Vol 69 (4) ◽  
pp. 2025-2030 ◽  
Author(s):  
Shuhua Yang ◽  
Shunji Sugawara ◽  
Toshihiko Monodane ◽  
Masahiro Nishijima ◽  
Yoshiyuki Adachi ◽  
...  

ABSTRACT Teichuronic acid (TUA), a component of the cell walls of the gram-positive organism Micrococcus luteus (formerlyMicrococcus lysodeikticus), induced inflammatory cytokines in C3H/HeN mice but not in lipopolysaccharide (LPS)-resistant C3H/HeJ mice that have a defect in the Toll-like receptor 4 (TLR4) gene, both in vivo and in vitro, similarly to LPS (T. Monodane, Y. Kawabata, S. Yang, S. Hase, and H. Takada, J. Med. Microbiol. 50:4–12, 2001). In this study, we found that purified TUA (p-TUA) induced tumor necrosis factor alpha (TNF-α) in murine monocytic J774.1 cells but not in mutant LR-9 cells expressing membrane CD14 at a lower level than the parent J774.1 cells. The TNF-α-inducing activity of p-TUA in J774.1 cells was completely inhibited by anti-mouse CD14 monoclonal antibody (MAb). p-TUA also induced interleukin-8 (IL-8) in human monocytic THP-1 cells differentiated to macrophage-like cells expressing CD14. Anti-human CD14 MAb, anti-human TLR4 MAb, and synthetic lipid A precursor IVA, an LPS antagonist, almost completely inhibited the IL-8-inducing ability of p-TUA, as well as LPS, in the differentiated THP-1 cells. Reduced p-TUA did not exhibit any activities in J774.1 or THP-1 cells. These findings strongly suggested that M. luteus TUA activates murine and human monocytic cells in a CD14- and TLR4-dependent manner, similar to LPS.


2010 ◽  
Vol 79 (3) ◽  
pp. 1118-1123 ◽  
Author(s):  
Amanda McBride ◽  
Kamlesh Bhatt ◽  
Padmini Salgame

ABSTRACTPublished work indicates that the contribution of Toll-like receptor 2 (TLR2) to host resistance during acuteMycobacterium tuberculosisinfection is marginal. However, in these studies, TLR2 participation in the memory immune response toM. tuberculosiswas not determined. The substantialin vitroevidence thatM. tuberculosisstrongly triggers TLR2 on dendritic cells and macrophages to bring about either activation or inhibition of antigen-presenting cell (APC) functions, along with accumulating evidence that memory T cell development can be calibrated by TLR signals, led us to question the role of TLR2 in host resistance to secondary challenge withM. tuberculosis. To address this question, a memory immunity model was employed, and the response of TLR2-deficient (TLR2 knockout [TLR2KO]) mice following a secondary exposure toM. tuberculosiswas compared to that of wild-type (WT) mice based on assessment of the bacterial burden, recall response, phenotype of recruited T cells, and granulomatous response. We found that upon rechallenge withM. tuberculosis, both WT and TLR2KO immune mice displayed similarly enhanced resistance to infection in comparison to their naïve counterparts. The frequencies ofM. tuberculosis-specific gamma interferon (IFN-γ)-producing T cells, the phenotypes of recruited T cells, and the granulomatous responses were also similar between WT and TLR2KO immune mice. Together, the findings from this study indicate that TLR2 signaling does not influence memory immunity toM. tuberculosis.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 837-837
Author(s):  
John W. Semple ◽  
Edwin R. Speck ◽  
John Freedman

Abstract Previous studies have demonstrated that recipient mice require the production of nitric oxide (NO) within their antigen presenting cells (APC) in order to generate IgG anti-donor immunity against allogeneic platelet transfusions. NO has a complex biochemistry and several of its conjurors could be involved in this response; the most obvious is peroxynitrite (ONOO-) generated by the spontaneous combination of NO and superoxide (O2•−). ONOO- is a potent oxidant that can spontaneously nitrosylate lysine and tyrosine residues in proteins within the phagolysosome. To address the role of ONOO- in platelet immunity, we transfused GP91 PHOX knockout mice that lack the ability to produce O2•− and thus ONOO-. Results show that when wild type C57BL/6 mice were transfused with allogeneic BALB/c platelets, they developed a weak IgG anti-donor antibody response by the fifth transfusion. In contrast, PHOX KO mice generated IgG anti-donor antibodies by the 2nd transfusion and their IgG anti-donor antibody titres were significantly higher than the WT recipients. This suggested that ONOO- and protein nitrosylation may be linked with an immunosuppressive event within the recipient. This was confirmed by demonstrating that in vitro nitrosylation of platelet antigens with the ONOO- donor SIN-1 inhibited the ability of the platelets to mount an IgG immune response when transfused into allogeneic recipients. Nitrosylated platelet antigen trafficking within recipient APC was assessed by using adherent macrophages and various inhibitors of processing. When adherent APC were pulsed with nitrosylated platelet antigens in the presence of either Brefeldin A or proteosome inhibitors, IgG anti-platelet immunity against the platelets was restored. Furthermore, the IgG immunity could also be rescued against the nitrsosylated platelets if the recipients were first depleted of CD8+ T cells by injection of a monoclonal antibody. These results suggest that if platelet antigens are nitrosylated within antigen presenting cells, they are preferentially shunted to the MHC class I processing pathway and presented to CD8+ T cells that suppress the IgG immune response. Thus, it appears that reactive oxygen species act as intracellular regulators that determine whether a productive IgG immune response against platelet transfusions will occur.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2649-2649 ◽  
Author(s):  
Xiaochuan Chen ◽  
Chien-Hsing Chang ◽  
David Goldenberg

Abstract Milatuzumab (hLL1, Immunomedics, Inc.), a humanized anti-CD74 immunoglobulin-G monoclonal antibody (MAb), has been shown to have therapeutic activity against CD74-expressing B-cell malignancies in vitro and in xenografts models, and is in clinical evaluation as a therapeutic MAb for non-Hodgkin lymphoma, chronic lymphocytic leukemia, and multiple myeloma. Since it is unclear whether this MAb has any effects on human antigen-presenting cells that express CD74, we investigated the binding efficiency, viability, and functional modulation of human dendritic cells (DC), the professional and most potent antigen-presenting cells, exposed to milatuzumab. We found that milatuzumab bound efficiently with B cells, monocytes, and different subsets of blood DCs including myeloid DC1 (BDCA-1+), myeloid DC2 (BDCA-3+) and plasmacytoid DC (BDCA-2+) in human PBMC, as well as with monocyte-derived immature DCs, but not LPS-matured DCs. The side-by-side comparative cytotoxicity assay showed that milatuzumab, in the presence of a second antibody for cross-linking (GAH, the F(ab′)2 of goat anti-human IgG Fcgamma-specific), dramatically reduced the cell viability of Daudi B-lymphoma cells, but did not influence the cell viability or induce apoptosis in monocyte-derived DCs, even at high concentations up to 50 μg/ml. At the concentrations ranging from 0.05 to 5 μg/ml, milatuzumab upregulated the expression of the antigen-presenting molecule, HLA-DR, and costimulatory molecules, CD54 and CD86, in human monocyte-derived DCs in a moderate, but dose-dependent manner, suggesting that milatuzumab could enhance DC constitutive maturation. Although this effect was not reflected by an enhanced T-cell expansion, as shown by unaltered CFSE-low, -medium, and –high peaks in total and CD4+ and CD4− T cells, milatuzumab-treated DCs could moderately promote the differentiation of CD4+ naïve T cells toward more Th1 effector cells, suggesting that milatuzumab can modulate DC functions, inducing the polarization and differentiation of functional Th cells. These data highlight the prospects of milatuzumab as a novel immunotherapeutic agent that possesses not only direct anti-proliferative effects against CD74+ hematological malignancies, but also some regulatory effects on DC-mediated immune functions, and no cytotoxic effect on DCs.


2009 ◽  
Vol 16 (11) ◽  
pp. 1615-1623 ◽  
Author(s):  
Shunsuke Takenaka ◽  
Sarah McCormick ◽  
Ekaterina Safroneeva ◽  
Zhou Xing ◽  
Jack Gauldie

ABSTRACT It is recognized that functional activities of antigen-presenting cells (APCs) in mucosal tissue sites differ from those of systemic APCs; however, it is unknown whether there are further differences between APC populations residing in different mucosal sites. In this study, we directly compared murine CD11c+ APCs isolated from colon, lung, and spleen and found that APCs isolated from these tissues differ considerably in Toll-like receptor (TLR) expression and responses to in vitro TLR ligand stimulation. We also provide evidence that tissue microenvironments dictate distinct patterns of TLR expression by CD11c+ APCs in different mucosal tissues. Moreover, CD11c+ cells isolated from different tissues have varied capacities to induce the development of T helper 1 (Th1), Th2, or regulatory CD4+ T cells. Thus, unique tissue microenvironments have a significant influence on determining TLR expression by CD11c+ cells that migrate to and reside in each mucosal tissue and are likely to modulate their functional activities.


2014 ◽  
Vol 82 (11) ◽  
pp. 4553-4562 ◽  
Author(s):  
Daniela Chessa ◽  
Luisella Spiga ◽  
Nicola De Riu ◽  
Paola Delaconi ◽  
Vittorio Mazzarello ◽  
...  

ABSTRACTSalmonella entericasubsp.entericaserovar (serotype) Abortusovis is a member of theEnterobacteriaceae. This serotype is naturally restricted to ovine species and does not infect humans. Limited information is available about the immune response of sheep toS. Abortusovis.S. Abortusovis, likeSalmonella entericasubsp.entericaserovar Typhi, causes a systemic infection in which, under natural conditions, animals are not able to raise a rapid immune response. Failure to induce the appropriate response allows pathogens to reach the placenta and results in an abortion. Lipopolysaccharides (LPSs) are pathogen-associated molecular patterns (PAMPs) that are specific to bacteria and are not synthesized by the host. Toll-like receptors (TLRs) are a family of receptors that specifically recognize PAMPs. As a first step, we were able to identify the presence of Toll-like receptor 4 (TLR4) on the ovine placenta by using an immunohistochemistry technique. To our knowledge, this is the first work describing the interaction betweenS. Abortusovis LPS and TLR4. Experiments using an embryonic cell line (HEK293) transfected with human and ovine TLR4s showed a reduction of interleukin 8 (IL-8) production byS. Abortusovis andSalmonella entericasubsp.entericaserovar Paratyphi upon LPS stimulation compared toSalmonella entericasubsp.entericaserovar Typhimurium. Identical results were observed using heat-killed bacteria instead of LPS. Based on data obtained with TLR4in vitrostimulation, we demonstrated that the serotypeS. Abortusovis is able to successfully evade the immune system whereasS. Typhimurium and other serovars fail to do so.


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