scholarly journals Neutrophil Gelatinase–Associated Lipocalin Protects from ANCA-Induced GN by Inhibiting TH17 Immunity

2020 ◽  
Vol 31 (7) ◽  
pp. 1569-1584 ◽  
Author(s):  
Adrian Schreiber ◽  
Anthony Rousselle ◽  
Jan Klocke ◽  
Sebastian Bachmann ◽  
Suncica Popovic ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Chimeric Mice ◽  
Wild Type ◽  
Neutrophil Gelatinase Associated Lipocalin ◽  
Anca Associated Vasculitis ◽  
Cell Immunity ◽  
Neutrophil Gelatinase ◽  
Deficient Mice

BackgroundNeutrophil gelatinase–associated lipocalin (NGAL) is a diagnostic marker of intrinsic kidney injury produced by damaged renal cells and by neutrophils. ANCA-associated vasculitis features necrotizing crescentic GN (NCGN), and ANCA-activated neutrophils contribute to NCGN. Whether NGAL plays a mechanistic role in ANCA-associated vasculitis is unknown.MethodsWe measured NGAL in patients with ANCA-associated vasculitis and mice with anti-myeloperoxidase (anti-MPO) antibody–induced NCGN. We compared kidney histology, neutrophil functions, T cell proliferation and polarization, renal infiltrating cells, and cytokines in wild-type and NGAL-deficient chimeric mice with anti-MPO antibody–induced NCGN. To assess the role of TH17 immunity, we transplanted irradiated MPO-immunized MPO-deficient mice with bone marrow from either wild-type or NGAL-deficient mice; we also transplanted irradiated MPO-immunized MPO/IL-17A double-deficient mice with bone marrow from either IL-17A–deficient or NGAL/IL-17A double-deficient mice.ResultsMice and patients with active ANCA-associated vasculitis demonstrated strongly increased serum and urinary NGAL levels. ANCA-stimulated neutrophils released NGAL. Mice with NGAL-deficient bone marrow developed worsened MPO-ANCA–induced NCGN. Intrinsic neutrophil functions were similar in NGAL-deficient and wild-type neutrophils, whereas T cell immunity was increased in chimeric mice with NGAL-deficient neutrophils with more renal infiltrating TH17 cells. NGAL-expressing neutrophils and CD3+ T cells were in close proximity in kidney and spleen. CD4+ T cells showed no intrinsic difference in proliferation and polarization in vitro, whereas iron siderophore–loaded NGAL suppressed TH17 polarization. We found significantly attenuated NCGN in IL-17A–deficient chimeras compared with MPO-deficient mice receiving wild-type bone marrow, as well as in NGAL/IL-17A–deficient chimeras compared with NGAL-deficient chimeras.ConclusionsOur findings support that bone marrow–derived, presumably neutrophil, NGAL protects from ANCA-induced NCGN by downregulating TH17 immunity.

scholarly journals A role for CD9 molecules in T cell activation.

1996 ◽  
Vol 184 (2) ◽  
pp. 753-758 ◽  
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.

Role of α/β and γ/δ T cells in renal ischemia-reperfusion injury

2007 ◽  
Vol 293 (3) ◽  
pp. F741-F747 ◽  
Author(s):  
Kathrin Hochegger ◽  
Tobias Schätz ◽  
Philipp Eller ◽  
Andrea Tagwerker ◽  
Dorothea Heininger ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Wild Type ◽  
Renal Ischemia Reperfusion Injury ◽  
Deficient Mice

T cells have been implicated in the pathogenesis of renal ischemia-reperfusion injury (IRI). To date existing data about the role of the T cell receptor (Tcr) are contradictory. We hypothesize that the Tcr plays a prominent role in the late phase of renal IRI. Therefore, renal IRI was induced in α/β, γ/δ T cell-deficient and wild-type mice by clamping renal pedicles for 30 min and reperfusing for 24, 48, 72, and 120 h. Serum creatinine increased equally in all three groups 24 h after ischemia but significantly improved in Tcr-deficient animals compared with wild-type controls after 72 h. A significant reduction in renal tubular injury and infiltration of CD4+ T-cells in both Tcr-deficient mice compared with wild-type controls was detected. Infiltration of α/β T cells into the kidney was reduced in γ/δ T cell-deficient mice until 72 h after ischemia. In contrast, γ/δ T cell infiltration was equal in wild-type and α/β T cell-deficient mice, suggesting an interaction between α/β and γ/δ T cells. Data from γ/δ T cell-deficient mice were confirmed by in vivo depletion of γ/δ T cells in C57BL/6 mice. Whereas α/β T cell-deficient mice were still protected after 120 h, γ/δ T cell-deficient mice showed a “delayed wild-type phenotype” with a dramatic increase in kidney-infiltrating α/β, Tcr-expressing CD4+ T-cells. This report provides further evidence that α/β T cells are major effector cells in renal IRI, whereas γ/δ T cells play a role as mediator cells in the first 72 h of renal IRI.

A Critical Role for Innate Immunity In Allogeneic Hematopoietic Cell Rejection Via the TLR4/TRIF Pathway

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 77-77
Author(s):  
Hong Xu ◽  
Jun Yan ◽  
Ziqiang Zhu ◽  
Yiming Huang ◽  
Yujie Wen ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Innate Immunity ◽  
T Cells ◽  
Immune System ◽  
T Cell ◽  
Innate Immune System ◽  
Critical Role ◽  
Innate Immune ◽  
Wild Type

Abstract Abstract 77 Adaptive immunity, especially T cells, has long been believed to be the dominant immune barrier in allogeneic transplantation. Targeting host T cells significantly reduces conditioning for bone marrow cell (BMC) engraftment. Innate immunity has been recently shown to pose a significant barrier in solid organ transplantation, but has not been addressed in bone marrow transplantation (BMT). Using T cell deficient (TCR-β/δ−/−) or T and B cell deficient (Rag−/−) mice, we found that allogeneic BMC rejection occurred early before the time required for T cell activation and was T- and B-cell independent, suggesting an effector role for innate immune cells in BMC rejection. Therefore, we hypothesized that by controlling both innate and adaptive immunity, the donor BMC would have a window of advantage to engraft. Survival of BMC in vivo was significantly improved by depleting recipient macrophages and/or NK cells, but not neutrophils. Moreover, depletion of macrophages and NK cells in combination with co-stimulatory blockade with anti-CD154 and rapamycin as a novel form of conditioning resulted in 100% allogeneic engraftment without any irradiation and T cell depletion. Donor chimerism remained stable and durable up to 6 months. Moreover, specific Vβ5½ and Vβ11 clonal deletion was detected in host CD4+ T cells in chimeras, indicating central tolerance to donor alloantigens. Whether and how the innate immune system recognizes or responds to allogeneic BMCs remains unknown. Toll-like receptors (TLRs) are a class of proteins that play a key role in the innate immune system. The signaling function of TLR depends on intracellular adaptors. The adaptor MyD88 transmits signals emanating from all TLR, except TLR3 while TRIF specifically mediates TLR3 and TLR4 signaling via type 1 IFN. To further determine the innate signaling pathways in allogeneic BMC rejection, B6 background (H2b) MyD88−/− and TRIF−/− mice were conditioned with anti-CD154/rapamycin plus 100 cGy total body irradiation and transplanted with 15 × 106 BALB/c (H2d) BMC. Only 33.3% of MyD88−/− recipients engrafted at 1 month, resembling outcomes for wild-type B6 mice. In contrast, 100% of TRIF−/− mice engrafted. The level of donor chimerism in TRIF−/− mice was 5.1 ± 0.6% at one month, significantly higher than in MyD88−/− and wild-type B6 controls (P < 0.005). To determine the mechanism of innate signaling in BMC rejection, we examined whether TRIF linked TLR3 or TLR4 is the key pattern recognition receptor involved in BMC recognition. To this end, TLR3−/− and TLR4−/− mice were transplanted with BALB/c BMC with same conditioning. None of the TLR3−/− mice engrafted. In contrast, engraftment was achieved in 100% of TLR4−/− mice up to 6 months follow up. Taken together, these results suggest that rejection of allogeneic BMC is uniquely dependent on the TLR4/TRIF signaling pathway. Thus, our results clearly demonstrate a previously unappreciated role for innate immunity in allogeneic BMC rejection. Our current findings are distinct from prior reports demonstrating a critical role of MyD88 in rejection of allogeneic skin grafts and lung, and may reflect unique features related to BMC. The findings of the role of innate immunity in BMC rejection would lead to revolutionary changes in our understanding and management of BMT. This would be informative in design of more specific innate immune targeted conditioning proposals in BMT to avoid the toxicity. Disclosures: Bozulic: Regenerex LLC: Employment. Ildstad:Regenerex LLC: Equity Ownership.

Absence of Coronin 1B in Donor T Cells Diminishes Acute Gvhd By Impairing T Cell Accumulation in Secondary Lymphoid Tissue

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1880-1880
Author(s):  
Trisha Dant ◽  
Danny Bruce ◽  
Leshara Fulton ◽  
Michelle West ◽  
Niko Foger ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Lymphoid Tissue ◽  
Acute Gvhd ◽  
Wild Type ◽  
Target Organs ◽  
Donor Cells ◽  
Donor T Cells

Abstract Allogeneic stem cell transplant is a standard treatment for patients with high-risk and relapsed myeloid and lymphoid malignancies. However, donor T cells from the stem cell graft mediate graft-versus-host disease (GVHD), which is a common cause of morbidity and mortality for transplant recipients. Our group and others have shown that migration of donor T cells into secondary lymphoid tissue (SLT) and subsequent migration to target organs is critical to the pathogenesis of acute GVHD. The Coronin family of proteins consists of actin-binding proteins, which regulate filament formation by interacting with the Arp2/3 complex. Coronin 1B, a ubiquitously expressed member of the Coronin family, is required for lamellipodial protrusion and effective cell migration. Previous work has not evaluated a role for this protein in the function of T lymphocytes or during acute GVHD. To evaluate the effect of Coronin 1B in acute GVHD pathogenesis, we transplanted B6 T cell depleted bone marrow cells with wild type or Coronin 1B-/- T cells to lethally irradiated B6D2 and BALB/c recipient mice and evaluated clinical score of GVHD and overall survival. B6D2 recipients of Coronin 1B-/- T cells demonstrated 100% survival (Figure 1A. p< .001 as determined by Log-rank (Mantel-Cox) test) and significantly decreased clinical scores after transplant. This was confirmed with improvement in survival in BALB/c recipients of Coronin 1B-/- T cells. Additionally, Coronin 1B-/- T cells were capable of eliminating P815 tumor cells, indicating that loss of Coronin 1B does not inhibit graft-versus-tumor activity. By day 12 post- transplant, all mice receiving bone marrow alone developed tumor compared to none of the mice receiving Coronin 1B-/- T Cells. However, protection was not complete as 40% of Coronin 1B-/- T cell recipients developed tumor by day 23. To determine the effect of Coronin 1B on T cell migration during GVHD, B6D2 recipients were given GFP-expressing wild type or Coronin 1B-/- T cells along with T cell depleted bone marrow. Lymphoid tissue and target organs were harvested and analyzed by flow cytometry or GFP ELISA. We observed decreased accumulation of Coronin 1B-/- CD4+ (Figure 1B. p< .01 as determined by Student's t -test) and CD8+ T cells in the inguinal lymph node, mesenteric lymph node, and the spleen 4 days after transplant with no difference in accumulation in lymphoid tissue on days 7 and 14 after transplant. Additionally, we found decreased accumulation of Coronin 1B-/- donor T cells in the lung, colon and spleen 14 days after transplant (Figure 1C. p< .05 by Student's t -test). We also quantified the amount of cytokine in target organs by ELISA, and observed a decrease in IFN-γ and TNF-α in the colon 14 days after transplant. Our data demonstrate that Coronin 1B-/- T cells elicit reduced GVHD compared to wild type T cells. This was correlated with decreased accumulation of Coronin 1B-/- T cells in SLT early after transplant. These data indicate that targeting the migration of T cells to SLT is a viable approach to prevent acute GVHD. Figure 1. (A) Kaplan Meier curve comparing B6D2 recipients of Coronin 1B-/- T cells and wild type (WT) T Cells. (B) Decreased accumulation of Coronin 1B-/- T Cells 4 Days after transplant. For panels (B) and (C) black bars indicate recipients of WT T cells while red bars indicate recipients of Coronin 1B-/- T cells. Inguinal lymph nodes (ILN) were pooled from n=5 mice from each group. Spleens were analyzed individually. GFP expressing donor cells were analyzed by flow cytometry. Representative image of two experiments. (C) Coronin 1B-/- T cells express decreased accumulation in the lung, colon and spleen 14 days after transplant. Target organs were analyzed by GFP ELISA to detect GFP+ Donor Cells (n=5 in each group). Figure 1. (A) Kaplan Meier curve comparing B6D2 recipients of Coronin 1B-/- T cells and wild type (WT) T Cells. (B) Decreased accumulation of Coronin 1B-/- T Cells 4 Days after transplant. For panels (B) and (C) black bars indicate recipients of WT T cells while red bars indicate recipients of Coronin 1B-/- T cells. Inguinal lymph nodes (ILN) were pooled from n=5 mice from each group. Spleens were analyzed individually. GFP expressing donor cells were analyzed by flow cytometry. Representative image of two experiments. (C) Coronin 1B-/- T cells express decreased accumulation in the lung, colon and spleen 14 days after transplant. Target organs were analyzed by GFP ELISA to detect GFP+ Donor Cells (n=5 in each group). Disclosures No relevant conflicts of interest to declare.

scholarly journals Lack of CD4+ T Cells Does Not Affect Induction of CD8+ T-Cell Immunity against Encephalitozoon cuniculi Infection

2000 ◽  
Vol 68 (11) ◽  
pp. 6223-6232 ◽  
Author(s):  
Magali Moretto ◽  
Lori Casciotti ◽  
Brigit Durell ◽  
Imtiaz A. Khan
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Response ◽  
T Cell Response ◽  
T Cell Immunity ◽  
Cell Mediated Immunity ◽  
Wild Type ◽  
Encephalitozoon Cuniculi ◽  
Cell Immunity ◽  
Mouse Tissues

ABSTRACT Cell-mediated immunity has been reported to play an important role in defense against Encephalitozoon cuniculi infection. Previous studies from our laboratory have underlined the importance of cytotoxic CD8+ T lymphocytes (CTL) in survival of mice infected with E. cuniculi. In the present study, immune response against E. cuniculi infection in CD4+T-cell-deficient mice was evaluated. Similar to resistant wild-type animals, CD4−/− mice were able to resolve E. cuniculi infection even at a very high challenge dose (5 × 107 spores/mouse). Tissues from infected CD4−/− mice did not exhibit higher parasite loads in comparison to the parental wild-type mice. Conversely, at day 21 postinfection, susceptible CD8−/− mice had 1014 times more parasites in the liver compared to control wild-type mice. Induction of the CD8+ T-cell response in CD4−/− mice against E. cuniculi infection was studied. Interestingly, a normal antigen-specific CD8+T-cell response to E. cuniculi infection was observed in CD4−/− mice (precursor proliferation frequency, 1/2.5 × 104 versus 1/104 in wild-type controls). Lack of CD4+ T cells did not alter the magnitude of the antigen-specific CTL response (precursor CTL frequency; 1/1.4 × 104 in CD4−/− mice versus 1/3 × 104 in control mice). Adoptive transfer of immune CD8+ T cells from both CD4−/− and wild-type animals prevented the mortality in CD8−/− mice.E. cuniculi infection thus offers an example of an intracellular parasitic infection where CD8+ T-cell immunity can be induced in the absence of CD4+ T cells.

scholarly journals Vaccinated C57BL/6 Mice Develop Protective and Memory T Cell Responses to Coccidioides posadasii Infection in the Absence of Interleukin-10

2013 ◽  
Vol 82 (2) ◽  
pp. 903-913 ◽  
Author(s):  
Chiung-Yu Hung ◽  
Natalia Castro-Lopez ◽  
Garry T. Cole
Keyword(s):  
T Cells ◽  
T Cell ◽  
Ex Vivo ◽  
Interleukin 10 ◽  
Effector Memory ◽  
Wild Type ◽  
Coccidioides Posadasii ◽  
Content Type ◽  
Cell Immunity ◽  
Ifn Γ

ABSTRACTHigh concentrations of lung tissue-associated interleukin-10 (IL-10), an anti-inflammatory and immunosuppressive cytokine, correlate with susceptibility of mice toCoccidioidesspp. infection. In this study, we found that macrophages, dendritic cells, neutrophils, and both CD8+and CD4+T cells recruited toCoccidioides posadasii-infected lungs of nonvaccinated and vaccinated mice contributed to the production of IL-10. The major IL-10-producing leukocytes were CD8+T cells, neutrophils, and macrophages in lungs of nonvaccinated mice, while both Foxp3+and Foxp3−subsets of IL-10+CD4+T cells were significantly elevated in vaccinated mice. Profiles of the recruited leukocytes in lungs revealed that only CD4+T cells were significantly increased inIL-10−/−knockout mice compared to their wild-type counterparts. Furthermore,ex vivorecall assays showed that CD4+T cells isolated from vaccinatedIL-10−/−mice compared to vaccinated wild-type mice produced significantly higher amounts of IL-2, gamma interferon (IFN-γ), IL-4, IL-6, and IL-17A in the presence of a coccidioidal antigen, indicating that IL-10 suppresses Th1, Th2, and Th17 immunity toCoccidioidesinfection. Analysis of absolute numbers of CD44+CD62L−CD4+T effector memory T cells (TEM) and IFN-γ- and IL-17A-producing CD4+T cells in the lungs ofCoccidioides-infected mice correlated with better fungal clearance in nonvaccinatedIL-10−/−mice than in nonvaccinated wild-type mice. Our results suggest that IL-10 suppresses CD4+T-cell immunity in nonvaccinated mice duringCoccidioidesinfection but does not impede the development of a memory response nor exacerbate immunopathology of vaccinated mice over at least a 4-month period after the last immunization.

scholarly journals Interleukin-1R Signaling Is Essential for Induction of Proapoptotic CD8 T Cells, Viral Clearance, and Pathology during Lymphocytic Choriomeningitis Virus Infection in Mice

2012 ◽  
Vol 86 (16) ◽  
pp. 8713-8719 ◽  
Author(s):  
Lars T. Joeckel ◽  
Reinhard Wallich ◽  
Sunil S. Metkar ◽  
Christopher J. Froelich ◽  
Markus M. Simon ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Interleukin 1 ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Viral Clearance ◽  
T Cell Immunity ◽  
Cell Immunity ◽  
Deficient Mice

The T cell granule exocytosis pathway is essential to control hepatotropic lymphocytic choriomeningitis virus strain WE (LCMV-WE) but also contributes to the observed pathology in mice. Although effective antiviral T cell immunity and development of viral hepatitis are strictly dependent on perforin and granzymes, the molecular basis underlying induction of functionally competent virus-immune T cells, including participation of the innate immune system, is far from being resolved. We demonstrate here that LCMV-immune T cells of interleukin-1 receptor (IL-1R)-deficient mice readily express transcripts for perforin and granzymes but only translate perforin, resulting in the lack of proapoptotic potentialin vitro. LCMV is not cleared in IL-1R-deficient mice, and yet the infected mice develop neither splenomegaly nor hepatitis. These results demonstrate that IL-1R signaling is central to the induction of proapoptotic CD8 T cell immunity, including viral clearance and associated tissue injuries in LCMV infection.

scholarly journals Enhanced Susceptibility of Galectin-1 Deficient Mice to Experimental Colitis

2021 ◽  
Vol 12 ◽  
Author(s):  
Raquel Fernandez-Perez ◽  
Mercedes Lopez-Santalla ◽  
Rebeca Sánchez-Domínguez ◽  
Omaira Alberquilla ◽  
Irene Gutiérrez-Cañas ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Inflammatory Response ◽  
Intestinal Inflammation ◽  
Experimental Colitis ◽  
Cell Trafficking ◽  
Wild Type ◽  
Cell Reactivity ◽  
Deficient Mice

Galectin-1 is a β-galactoside-binding lectin, ubiquitously expressed in stromal, epithelial, and different subsets of immune cells. Galectin-1 is the prototype member of the galectin family which shares specificity with β-galactoside containing proteins and lipids. Immunomodulatory functions have been ascribed to endogenous galectin-1 due to its induction of T cell apoptosis, inhibitory effects of neutrophils and T cell trafficking. Several studies have demonstrated that administration of recombinant galectin-1 suppressed experimental colitis by modulating adaptive immune responses altering the fate and phenotype of T cells. However, the role of endogenous galectin-1 in intestinal inflammation is poorly defined. In the present study, the well-characterized acute dextran sulfate sodium (DSS)-induced model of ulcerative colitis was used to study the function of endogenous galectin-1 during the development of intestinal inflammation. We found that galectin-1 deficient mice (Lgals1−/− mice) displayed a more severe intestinal inflammation, characterized by significantly elevated clinical scores, than their wild type counterparts. The mechanisms underlying the enhanced inflammatory response in colitic Lgals1−/− mice involved an altered Th17/Th1 profile of effector CD4+ T cells. Furthermore, increased frequencies of Foxp3+CD4+ regulatory T cells in colon lamina propria in Lgals1−/− mice were found. Strikingly, the exacerbated intestinal inflammatory response observed in Lgals1−/− mice was alleviated by adoptive transfer of wild type Foxp3+CD4+ regulatory T cells at induction of colitis. Altogether, these data highlight the importance of endogenous galectin-1 as a novel determinant in regulating T cell reactivity during the development of intestinal inflammation.

Empty peptide-receptive MHC class I molecules for efficient detection of antigen-specific T cells

2019 ◽  
Vol 4 (37) ◽  
pp. eaau9039 ◽  
Author(s):  
Sunil Kumar Saini ◽  
Tripti Tamhane ◽  
Raghavendra Anjanappa ◽  
Ankur Saikia ◽  
Sofie Ramskov ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class I ◽  
Single Step ◽  
Class I ◽  
Cell Detection ◽  
Wild Type ◽  
Efficient Detection ◽  
Cell Immunity ◽  
Mhc Class I Molecules

The peptide-dependent stability of MHC class I molecules poses a substantial challenge for their use in peptide-MHC multimer–based approaches to comprehensively analyze T cell immunity. To overcome this challenge, we demonstrate the use of functionally empty MHC class I molecules stabilized by a disulfide bond to link the α1 and α2 helices close to the F pocket. Peptide-loaded disulfide-stabilized HLA-A*02:01 shows complete structural overlap with wild-type HLA-A*02:01. Peptide-MHC multimers prepared using disulfide-stabilized HLA-A*02:01, HLA-A*24:02, and H-2Kb can be used to identify antigen-specific T cells, and they provide a better staining index for antigen-specific T cell detection compared with multimers prepared with wild-type MHC class I molecules. Disulfide-stabilized MHC class I molecules can be loaded with peptide in the multimerized form without affecting their capacity to stain T cells. We demonstrate the value of empty-loadable tetramers that are converted to antigen-specific tetramers by a single-step peptide addition through their use to identify T cells specific for mutation-derived neoantigens and other cancer-associated antigens in human melanoma.

Alloreactive Natural Killer Cells Rebuild Adaptive Immunity to Infections after Haploidentical Hematopoietic Transplantation.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3210-3210
Author(s):  
Loredana Ruggeri ◽  
Emanuela Burchielli ◽  
Katia Perruccio ◽  
Marusca Capanni ◽  
Martin Stern ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Acute Leukemia ◽  
Nk Cells ◽  
Leukemic Cells ◽  
Immune Recovery ◽  
Clinical Issue ◽  
Cell Immunity ◽  
Hematopoietic Transplantation

Abstract Transplantation of peripheral blood hematopoietic cells from HLA haplotype-mismatched family members is a therapeutic strategy for patients with high-risk acute leukemia who need transplantation and do not have matched donors. As T cell alloreactions cause lethal GvHD in mismatched transplants, only T cell-depleted hematopoietic grafts can be used. In adults, because of declining thymic function, immune-recovery originates from expansion of the mature T cells infused with the graft. In T cell depleted mismatched transplant immune recovery is hindered by the paucity of the starting T-cell population. Slow recovery of functional T cell immunity to pathogens is responsible for 35% infection-related mortality which remains the most pressing clinical issue. In murine MHC-haploidentical bone marrow transplant models we demonstrated donor-versus-recipient alloreactive NK cells ablate recipient-type lympho-hematopietic cells such as leukemic cells, the T cells that cause rejection and the antigen-presenting cells which trigger GvHD. Consequently mismatched T cell-replete transplants can be performed without GvHD (Ruggeri et al., Science 2002). Unexpectedly, in recent experiments, we observed alloreactive NK cells hastened immune-reconstitution. Pre-transplant infusion of alloreactive NK cells promoted brisk recovery of donor B and T cell precursors which matured correctly and of donor DCs. Rapidly reconstistuting DCs were crcuicial in protecting mice from infectious challenges. We next demonstrated:interaction between alloreactive NK cells and NK-susceptible recipient DCs alone was responsible for immune-rebuilding,NK conditioned mice remain receptive to accelerated immune rebuilding even when transplanted a week after NK conditioning, therefore the NK-DC interaction appears to release an as yet unknown immune-rebuilding factor which acts upon bone marrow and thymus microenvironements stably over time,quantitative PCR on bone marrow and thimus of NK conditioned mice shows several-fold increased expression of cytokines implicated in B, T and myeloid cell maturation, such as IL-7 and c-Kit ligand;the accelerated immune rebuilding effect can be reproduced by conditioning mice with the infusion of NK:DC co-culture supernatants. These observation prompted an analysis of infectious mortality in 178 acute leukemia patients who received haploidentical transplant at our Center. Transplantation from KIR ligand-mismatched (i.e., NK alloreactive) donors, in addition to controlling AML relapse, offers statistically significant protection from infectious mortality in AML and ALL patients. Studies are in progress to identify “immune rebuilding factor(s)”, produced in consequence of the interaction between donor alloreactive NK and recipient DCs, in the hope they might be exploited to boost immune-recovery and help reduce infection mortality after haploidentical hematopoietic transplantation.

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