scholarly journals Relief from Zmp1-Mediated Arrest of Phagosome Maturation Is Associated with Facilitated Presentation and Enhanced Immunogenicity of Mycobacterial Antigens

2011 ◽  
Vol 18 (6) ◽  
pp. 907-913 ◽  
Author(s):  
Pål Johansen ◽  
Antonia Fettelschoss ◽  
Beat Amstutz ◽  
Petra Selchow ◽  
Ying Waeckerle-Men ◽  
...  

ABSTRACTPathogenic mycobacteria escape host innate immune responses by blocking phagosome-lysosome fusion. Avoiding lysosomal delivery may also be involved in the capacity of mycobacteria to evade major histocompatibility complex (MHC) class I- or II-dependent T-cell responses. In this study, we used a genetic mutant ofMycobacterium bovisBCG that is unable to escape lysosomal transfer and show that presentation of mycobacterial antigens is affected by the site of intracellular residence. Compared to infection with wild-type BCG, infection of murine bone marrow-derived dendritic cells with a mycobacterial mutant deficient in zinc metalloprotease 1 (Zmp1) resulted in increased presentation of MHC class II-restricted antigens, as assessed by activation of mycobacterial Ag85A-specific T-cell hybridomas. Thezmp1deletion mutant was more immunogenicin vivo, as measured by delayed-type hypersensitivity (DTH), antigen-specific lymphocyte proliferation, and the frequency of antigen-specific gamma interferon (IFN-γ)-producing lymphocytes of both CD4 and CD8 subsets. In conclusion, our results suggest that phagosome maturation and lysosomal delivery of BCG facilitate mycobacterial antigen presentation and enhance immunogenicity.

1976 ◽  
Vol 144 (3) ◽  
pp. 776-787 ◽  
Author(s):  
R M Zinkernagel

In mice, primary footpad swelling after local infection with lymphocytic choriomeningitis virus (LCMV) and delayed-type hypersensitivity (DTH) adoptively transferred by LCMV immune lymphocytes are T-cell dependent. Nude mice do not develop primary footpad swelling, and T-cell depletion abrogates the capacity to transfer LCMV-specific DTH. Effector T cells involved in eliciting dose-dependent DTH are virus specific in that vaccinia virus-immune lymphocytes could not elicit DTH in LCMV-infected mice. The adoptive transfer of DTH is restricted to H-2K or H-2D compatible donor-recipient combinations. Distinct from the fowl-gamma-globulin DTH model, I-region compatibility is neither necessary nor alone sufficient. Whatever the mechanisms involved in this K- or D-region associated restriction in vivo, it most likely operates at the level of T-cell recognition of "altered self" coded in K or D. T cells associated with the I region (helper T cells and DTH-T cells to fowl-gamma-globulin) are specific for soluble, defined, and inert antigens. T cells associated with the K and D region (T cells cytotoxic in vitro and in vivo for acute LCMV-infected cells, DTH effector T cells, and anti-viral T cells) are specific for infectious, multiplying virus. The fact that T-cell specificity is differentially linked with the I region or with the K and D regions of H-2 may reflect the fundamental biological differences of these antigens. Although it cannot be excluded that separate functional subclasses of T-effector cells could have self-recognizers for different cell surface structures coded in I or K and D, it is more likely that the antigen parameters determine whether T cells are specific for "altered" I or "altered" K- or D-coded structures.


mBio ◽  
2014 ◽  
Vol 5 (4) ◽  
Author(s):  
Adria Carbo ◽  
Danyvid Olivares-Villagómez ◽  
Raquel Hontecillas ◽  
Josep Bassaganya-Riera ◽  
Rupesh Chaturvedi ◽  
...  

ABSTRACTThe development of gastritis duringHelicobacter pyloriinfection is dependent on an activated adaptive immune response orchestrated by T helper (Th) cells. However, the relative contributions of the Th1 and Th17 subsets to gastritis and control of infection are still under investigation. To investigate the role of interleukin-21 (IL-21) in the gastric mucosa duringH. pyloriinfection, we combined mathematical modeling of CD4+T cell differentiation within vivomechanistic studies. We infected IL-21-deficient and wild-type mice withH. pyloristrain SS1 and assessed colonization, gastric inflammation, cellular infiltration, and cytokine profiles. ChronicallyH. pylori-infected IL-21-deficient mice had higherH. pyloricolonization, significantly less gastritis, and reduced expression of proinflammatory cytokines and chemokines compared to these parameters in infected wild-type littermates. Thesein vivodata were used to calibrate anH. pyloriinfection-dependent, CD4+T cell-specific computational model, which then described the mechanism by which IL-21 activates the production of interferon gamma (IFN-γ) and IL-17 during chronicH. pyloriinfection. The model predicted activated expression of T-bet and RORγt and the phosphorylation of STAT3 and STAT1 and suggested a potential role of IL-21 in the modulation of IL-10. Driven by our modeling-derived predictions, we found reduced levels of CD4+splenocyte-specifictbx21androrcexpression, reduced phosphorylation of STAT1 and STAT3, and an increase in CD4+T cell-specific IL-10 expression inH. pylori-infected IL-21-deficient mice. Our results indicate that IL-21 regulates Th1 and Th17 effector responses during chronicH. pyloriinfection in a STAT1- and STAT3-dependent manner, therefore playing a major role controllingH. pyloriinfection and gastritis.IMPORTANCEHelicobacter pyloriis the dominant member of the gastric microbiota in more than 50% of the world’s population.H. pyloricolonization has been implicated in gastritis and gastric cancer, as infection withH. pyloriis the single most common risk factor for gastric cancer. Current data suggest that, in addition to bacterial virulence factors, the magnitude and types of immune responses influence the outcome of colonization and chronic infection. This study uses a combined computational and experimental approach to investigate how IL-21, a proinflammatory T cell-derived cytokine, maintains the chronic proinflammatory T cell immune response driving chronic gastritis duringH. pyloriinfection. This research will also provide insight into a myriad of other infectious and immune disorders in which IL-21 is increasingly recognized to play a central role. The use of IL-21-related therapies may provide treatment options for individuals chronically colonized withH. pylorias an alternative to aggressive antibiotics.


2020 ◽  
Author(s):  
BW Greatrex ◽  
Alison Daines ◽  
S Hook ◽  
DH Lenz ◽  
W McBurney ◽  
...  

© 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. In an attempt to discover a new synthetic vaccine adjuvant, the glycosylation of hederagenin, gypsogenin, and oleanolic acid acceptors with di- and trisaccharide donors to generate a range of mimics of natural product QS-21 was carried out. The saponins were formulated with phosphatidylcholine and cholesterol, and the structures analyzed by transmission electron microscopy. 3-O-(Manp(1→3)Glcp)hederagenin was found to produce numerous ring-like micelles when formulated, while C-28 choline ester derivatives preferred self-assembly and did not interact with the liposomes. When alone and in the presence of cholesterol and phospholipid, the choline ester derivatives produced nanocrystalline rods or helical micelles. The effects of modifying sugar stereochemistry and the aglycone on the immunostimulatory effects of the saponins was then evaluated using the activation markers MHC class II and CD86 in murine bone marrow dendritic cells. The most active saponin, 3-O-(Manp(1→3)Glcp)hederagenin, was stimulatory at high concentrations in cell culture, but this did not translate to strong responses in vivo.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Gobena Ameni ◽  
Paul Cockle ◽  
Konstantin Lyashchenko ◽  
Martin Vordermeier

Higher IFN-γresponses to mycobacterial antigens were observed inBos taurus(Holsteins) than inBos indicus(Zebu) cattle which could due to differences in antigen recognition profiles between the two breeds. The present study was conducted to evaluate mycobacterial antigen recognition profiles of the two breeds. Twenty-three mycobacterial antigens were tested on 46 skin test positive (24 Zebu and 22 Holstein) using enzyme-linked immunospot assay (ELISPOT) and multiple antigen print immunoassay (MAPIA). Herds from which the study cattle obtained were tested for Fasciola antibody. The T cells from both breeds recognized most of the mycobacterial antigens at lower and comparable frequencies. However, antigens such as CFP-10, ESAT-6, Rv0287, Rv0288, MPB87, Acr-2, Rv3616c, and Rv3879c were recognized at higher frequencies in zebu while higher frequencies of T cell responses were observed to Hsp65 in both breeds. Furthermore, comparable antibody responses were observed in both breeds; MPB83 being the sero-dominant antigen in both breeds. The prevalence of Fasciola antibody was 81% and similar in both breeds. This piece of work could not lead to a definitive conclusion if there are differences in mycobacterial recognition profiles between the two breeds warranting for further similar studies using sound sample size from the two breeds.


Blood ◽  
1988 ◽  
Vol 72 (4) ◽  
pp. 1148-1154 ◽  
Author(s):  
BR Blazar ◽  
MB Widmer ◽  
CC Soderling ◽  
S Gillis ◽  
DA Vallera

Abstract In vivo administration of murine recombinant granulocyte/macrophage colony stimulating factor (rGM-CSF) was evaluated for effects on survival and engraftment in an allogeneic murine bone marrow transplantation (BMT) model involving T-cell depletion of donor marrow. The model provides a high incidence of graft failure/rejection. Recipients of continuous subcutaneous infusions of rGM-CSF had a significant survival advantage when compared with untreated controls. However, a significantly lower incidence of donor cell engraftment was noted. Hematological parameters were not substantially affected. When rGM-CSF was administered intraperitoneally (IP), twice daily injections closely approximated the effects of continuous infusion on survival. Single IP injections were without significant effects on survival or engraftment. These results demonstrate that prolonged frequent in vivo exposure to rGM-CSF can significantly improve survival but significantly decreases donor cell repopulation in recipients of T-cell- depleted histoincompatible marrow grafts.


Author(s):  
M. Christofi ◽  
S. Le Sommer ◽  
C. Mölzer ◽  
I. P. Klaska ◽  
L. Kuffova ◽  
...  

Abstract Cell therapies for autoimmune diseases using tolerogenic dendritic cells (tolDC) have been promisingly explored. A major stumbling block has been generating stable tolDC, with low risk of converting to mature immunogenic DC (mDC), exacerbating disease. mDC induction involves a metabolic shift to lactate production from oxidative phosphorylation (OXPHOS) and β-oxidation, the homeostatic energy source for resting DC. Inhibition of glycolysis through the administration of 2-deoxy glucose (2-DG) has been shown to prevent autoimmune disease experimentally but is not clinically feasible. We show here that treatment of mouse bone marrow-derived tolDC ex vivo with low-dose 2-DG (2.5 mM) (2-DGtolDC) induces a stable tolerogenic phenotype demonstrated by their failure to engage lactate production when challenged with mycobacterial antigen (Mtb). ~ 15% of 2-DGtolDC express low levels of MHC class II and 30% express CD86, while they are negative for CD40. 2-DGtolDC also express increased immune checkpoint molecules PDL-1 and SIRP-1α. Antigen-specific T cell proliferation is reduced in response to 2-DGtolDC in vitro. Mtb-stimulated 2-DGtolDC do not engage aerobic glycolysis but respond to challenge via increased OXPHOS. They also have decreased levels of p65 phosphorylation, with increased phosphorylation of the non-canonical p100 pathway. A stable tolDC phenotype is associated with sustained SIRP-1α phosphorylation and p85-AKT and PI3K signalling inhibition. Further, 2-DGtolDC preferentially secrete IL-10 rather than IL-12 upon Mtb-stimulation. Importantly, a single subcutaneous administration of 2-DGtolDC prevented experimental autoimmune uveoretinitis (EAU) in vivo. Inhibiting glycolysis of autologous tolDC prior to transfer may be a useful approach to providing stable tolDC therapy for autoimmune/immune-mediated diseases.


1989 ◽  
Vol 170 (2) ◽  
pp. 449-466 ◽  
Author(s):  
M F van den Broek ◽  
E J Hogervorst ◽  
M C Van Bruggen ◽  
W Van Eden ◽  
R van der Zee ◽  
...  

We report that streptococcal cell wall (SCW)-induced arthritis in rats, a T cell-dependent chronic, erosive polyarthritis, can be prevented by pretreatment of the rats with the mycobacterial 65-kD heat shock protein. This 65-kD protein shows extensive amino acid homology with prokaryotic and eukaryotic 65-kD heat shock proteins and is a ubiquitous bacterial common antigen. Both the clinical and histopathologic manifestations of the arthritis were prevented completely when rats were pretreated with 50 micrograms of 65-kD protein intraperitoneally at 35, 25, 15, or 5 d before administration of SCW. In such protected rats, SCW-specific T cell responses were suppressed, as compared with responses in arthritic rats. Pretreatment with 65-kD protein had no effect on the production of antibodies against SCW, on a nonspecific inflammatory reaction (zymosan-induced arthritis), or on general cellular immunity in vivo (delayed type hypersensitivity reaction to a nonrelated protein antigen). Furthermore, the protection against SCW arthritis was transferable by splenic T cells to naive recipients. Our data show that pretreatment with the 65-kD mycobacterial heat shock protein protects rats against a subsequent bacterium-induced arthritis. This protection is immunologically specific and resides in the lymphoid cell population.


Blood ◽  
1990 ◽  
Vol 75 (3) ◽  
pp. 798-805 ◽  
Author(s):  
BR Blazar ◽  
DL Thiele ◽  
DA Vallera

Abstract Incubation of murine bone marrow and splenocytes with the dipeptide methyl ester, L-leucyl-L-leucine methyl ester (Leu-Leu-OMe), which results in the selective depletion of cytotoxic T cells and their precursors, natural killer cells, and monocytes, completely protected 30 recipients of fully allogeneic donor grafts from lethal graft-versus- host disease (GVHD). These results were comparable with those obtained in 30 recipients of anti-Thy 1.2 plus complement (C')-treated donor marrow. However, in contrast to antibody- and C'-dependent T-cell depletion, which reduces the level of donor cell engraftment in our model system, we did not observe such effects using Leu-Leu-OMe marrow pretreatment. As compared with the 24 H-2 typed recipients of anti-Thy 1.2 + C'-treated donor grafts, the 29 H-2 typed recipients of Leu-Leu- OMe-treated donor grafts had significantly (P less than .001) higher percentages of donor cells (mean = 93% v 74%) and significantly (P less than .001) lower percentages of host cells (mean = 6% v 15%) posttransplantation. In vitro limiting dilution assay (LDA) was performed to assess the comparative efficacy of cytolytic T-lymphocyte (CTL) precursor depletion by Leu-Leu-OMe or anti-Thy 1.2 + C' pretreatment. We observed greater levels of CTL precursor depletion in Leu-Leu-OMe treated as compared with anti-Thy 1.2 + C'-treated bone marrow plus spleen cells (BMS) obtained from nontransplanted mice. This suggests that the in vivo results cannot simply be attributed to a less efficacious functional inactivation of cytolytic T-cell precursors by Leu-Leu-OMe treatment as compared with anti-Thy 1.2 + C' treatment. Immunoreconstitution was similar in recipients of Leu-Leu-OMe-treated grafts and anti-Thy 1.2 + C'-treated grafts 100 days posttransplant. In our opinion, Leu-Leu-OMe marrow pretreatment deserves further investigation as a methodology to achieve GVHD prevention without significantly reducing the propensity toward host cell repopulation.


1999 ◽  
Vol 5 (7) ◽  
pp. 471-476 ◽  
Author(s):  
Fabrizio Poccia ◽  
Miroslav Malkovsky ◽  
Aaron Pollak ◽  
Vittorio Colizzi ◽  
Guido Sireci ◽  
...  

1997 ◽  
Vol 185 (12) ◽  
pp. 2133-2141 ◽  
Author(s):  
Elizabeth Ingulli ◽  
Anna Mondino ◽  
Alexander Khoruts ◽  
Marc K. Jenkins

Although lymphoid dendritic cells (DC) are thought to play an essential role in T cell activation, the initial physical interaction between antigen-bearing DC and antigen-specific T cells has never been directly observed in vivo under conditions where the specificity of the responding T cells for the relevant antigen could be unambiguously assessed. We used confocal microscopy to track the in vivo location of fluorescent dye-labeled DC and naive TCR transgenic CD4+ T cells specific for an OVA peptide–I-Ad complex after adoptive transfer into syngeneic recipients. DC that were not exposed to the OVA peptide, homed to the paracortical regions of the lymph nodes but did not interact with the OVA peptide-specific T cells. In contrast, the OVA peptide-specific T cells formed large clusters around paracortical DC that were pulsed in vitro with the OVA peptide before injection. Interactions were also observed between paracortical DC of the recipient and OVA peptide-specific T cells after administration of intact OVA. Injection of OVA peptide-pulsed DC caused the specific T cells to produce IL-2 in vivo, proliferate, and differentiate into effector cells capable of causing a delayed-type hypersensitivity reaction. Surprisingly, by 48 h after injection, OVA peptide-pulsed, but not unpulsed DC disappeared from the lymph nodes of mice that contained the transferred TCR transgenic population. These results demonstrate that antigen-bearing DC directly interact with naive antigen-specific T cells within the T cell–rich regions of lymph nodes. This interaction results in T cell activation and disappearance of the DC.


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