Impact of Donor-Derived Invariant Natural Killer T (iNKT) Cell Reconstitution After Allogeneic Haematopoietic Stem Cell Transplantation.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 346-346
Author(s):  
Marie T Rubio ◽  
Lucia Teixeira ◽  
Pierre Milpied ◽  
Emmanuel Bachy ◽  
Felipe Suarez ◽  
...  
Keyword(s):  
T Cell ◽  
Acute Gvhd ◽  
Group Versus ◽  
Inkt Cell ◽  
Haematopoietic Stem Cell ◽  
Inkt Cells ◽  
High Group ◽  
Allogeneic Hsct ◽  
Invariant Natural Killer ◽  
Grade Iii

Abstract Abstract 346 Introduction: Invariant Natural Killer T (iNKT) cells express a highly restricted T cell receptor (TCR) repertoire composed of a single invariant Va14Ja18 chain in mice and a Va24Ja18 chain in humans. In contrast to their conventional counterpart, iNKT cells recognize CD1d-bound glycolipids rather than peptides. iNKT cells have elicited a lively interest in the last years because of their implication in several immune responses including experimental graft-versus-host-disease (GVHD). In this study, we addressed the question whether human iNKT cells could be associated with the outcome of allogeneic haematopoietic stem cell transplantation (HSCT). Materials and methods: Forty-seven patients allografted for diverse hematological malignancies in our institution entered prospectively the study. We sequentially analyzed the reconstitution of peripheral blood CD1d tetramer + iNKT, CD56+ NK, and CD4+, CD8+, CD4+CD25high T cells for 90 days after allogeneic HSCT by flow cytometry. Results were correlated to the clinical evolution of allogeneic HSCT. Results: We observed two groups of patients according to their iNKT/106 T cell ratios on days 30, 60 and 90 after HSCT. Patients with at least one point above the normal ratio of 1000 iNKT/106 T cells were considered in the iNKT high group (n=17), while those with a poor reconstitution, defined by all points below that threshold, were analyzed in the iNKT low group (n=30). iNKT reconstitution was the only significant difference in terms of immune reconstitution between the two groups since reconstitution of T CD4+, CD8+, or CD4+CD25high and NK cells was similar at all time points in both groups. Chimerism, analyzed by PCR amplification of short tandem repeat markers, showed that in all cases iNKT displayed a 100% donor origin. Pre-transplant characteristics of patients were similar between the two groups except for the conditioning regimen and the source of stem cells. Patients in the iNKT high group had more often received a reduced-intensity conditioning (80.5% versus 46.7%, p=0.004) and peripheral blood stem cells (88.5% versus 53.6%, p=0.015). Occurrence and severity of acute GVHD was significantly reduced in the iNKT high group (23.5 % grade I-II and 0% grade III-IV) compared to the iNKT low group (66.7 % grade I-II and 26.6% grade III-IV), (p<0.001), while development of chronic GVHD was not significantly affected by the iNKT reconstitution (29.4 % in the iNKT high group versus 48.2% in the iNKT low group), (p=0.57). This lead to a significantly reduced toxicity related mortality (TRM) in the iNKT high group (8.2% versus 36.9% in the iNKT low group at 2 years), (p=0.028) without an increased risk of relapse (17.6% in the iNKT high group versus 16.7% in the iNKT low group) at 2 years, (p=0.877). Median follow up was 28.7 months. Overall survival was improved in the iNKT high group (86.3% versus 58.0% in the iNKT low group, at 2 years), (p=0.056) in a landmark analysis at day 90. These results prompted us to further analyze whether iNKT cell frequency could be a predictive marker of acute GVHD. In a subgroup analysis performed on patients with availabel data on day 14 post-HSCT (n=23), the risk of developing acute GVHD was significantly higher in patients with a iNKT/106 T cell ratio below 500 (92 % of aGVHD) in comparison to those with a ratio above 500 (40 % of aGVHD), (p=0.0028). Conclusion: Our data suggest that donor-derived iNKT cell reconstitution after allogeneic HSCT may represent a predictive factor of acute GVHD and a prognostic factor of transplant outcome. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Combination Therapy of Allogeneic HSCT and In Vivo Activated iNKT Cells Prevents Acute Gvhd While Augmenting GVL Effect

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4439-4439
Author(s):  
Samuel Zeng ◽  
Qingxiao Song ◽  
Shanshan Tang ◽  
Xi Wang ◽  
Yuchen Wang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
Combination Therapy ◽  
Cell Therapy ◽  
Natural Killer ◽  
Acute Gvhd ◽  
Inkt Cell ◽  
Inkt Cells ◽  
Allogeneic Hsct

Adult acute lymphoblastic leukemia (ALL) is a highly aggressive cancer with poor clinical prognosis and high relapse rate. Whereas allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective treatment for highly differentiated hematologic malignancies, allo-HSCT provides only limited benefits for treating ALL with relapses frequent. Additionally, the development of graft-versus-host-disease (GVHD) remains a major concern for allo-HSCT recipients. Invariant natural killer T (iNKT) cells are a subset of T lymphocytes that express both a semi-invariant T cell receptor and natural killer cell markers. They recognize lipid antigens presented by non-polymorphic CD1d and have been reported to directly target CD1d+ solid tumors. Many B-ALL, including the P210 B-ALL cell line, are also CD1d+. Clinically, increased iNKT cells have simultaneously been correlated with reduced risk of developing acute GVHD and lower rates of malignant relapse. Because iNKT cells comprise only a tiny fraction of total T cells, we established a protocol to insert an iNKT TCR into murine HSC, thereby generating retrogenic mice with 5-10x expansion of iNKT cells in spleen and liver. Although engineered T cell therapy, including CD19-CART therapy, has proven to be effective in inducing remission in many B-ALL patients, when used as a monotherapy, relapse remains a major obstacle. We therefore tested whether a combination of allo-HSCT and iNKT cell therapy could robustly prevent GVHD while preserving graft-versus-leukemia effects (GVL). To test whether the addition of iNKT cells into allo-graft was capable of preventing acute GVHD (aGVHD), lethally irradiated BALB/C were given B6 bone marrow (2.5 x 106) and whole splenocytes (2.5 x 106, 5 x 106, or 10 x 106) from either B6 or retrogenic B6-iNKT mice. Mice that received 5 x 106 B6 splenocytes developed lethal aGVHD and became moribund by Day 10. Half of the mice that received 2.5 x 106 B6 splenocytes develop lethal aGVHD and died by Day 20. In contrast, only half of the mice that received 5 x 106 or 10 x 106 B6-iNKT splenocytes developed lethal aGVHD by Day 20, and all recipients of 2.5 x 106 B6 splenocytes remained alive by Day 20, suggesting the addition of iNKT cells into allograft may reduce the severity of aGVHD. To test whether adding iNKT cells to allograft could enhance GVL without causing GVHD, BALB/C mice with pre-established P210 B-ALL leukemia were given allo-HSCT with or without iNKT cell addition. Initially, our data showed freshly isolated iNKT cells were rapidly cleared following transplantation. We therefore included lethally irradiated P210 loaded with α-Galactosylceramide (α-Galcer) as adjuvant, and were able to see robust expansion of iNKT cells in vitro and in vivo (>20% vs <1% in WT in BM and Liver). Additionally, we found that HSCT recipients that also received iNKT cells were able to fully clear bone marrow residing B-ALL cells by Day8, compared to less than half in control, suggesting an important role of iNKT cells for targeting bone marrow residing B-ALL cells to prevent relapse. Taken together, combination therapy of allogeneic HSCT with infusion of donor-type iNKT cells activated via irradiated α-Galcer-loaded host-type ALL represent a novel approach for preventing GVHD and augmenting GVL effect against ALL. Disclosures No relevant conflicts of interest to declare.

scholarly journals Graft invariant natural killer T-cell dose predicts risk of acute graft-versus-host disease in allogeneic hematopoietic stem cell transplantation

Blood ◽  
2012 ◽  
Vol 119 (21) ◽  
pp. 5030-5036 ◽  
Author(s):  
Aristeidis Chaidos ◽  
Scott Patterson ◽  
Richard Szydlo ◽  
Mohammed Suhail Chaudhry ◽  
Francesco Dazzi ◽  
...  
Keyword(s):  
Stem Cell ◽  
T Cell ◽  
Natural Killer ◽  
Inkt Cell ◽  
Inkt Cells ◽  
Cell Dose ◽  
Grade Ii ◽  
Clinically Significant ◽  
Invariant Natural Killer ◽  
Natural Killer T

Abstract Invariant natural killer T (iNKT) cells are powerful immunomodulatory cells that in mice regulate a variety of immune responses, including acute GVHD (aGVHD). However, their clinical relevance and in particular their role in clinical aGVHD are not known. We studied whether peripheral blood stem cell (PBSC) graft iNKT-cell dose affects on the occurrence of clinically significant grade II-IV aGVHD in patients (n = 57) undergoing sibling, HLA-identical allogeneic HSCT. In multivariate analysis, CD4− iNKT-cell dose was the only graft parameter to predict clinically significant aGVHD. The cumulative incidence of grade II-IV aGVHD in patients receiving CD4− iNKT-cell doses above and below the median were 24.2% and 71.4%, respectively (P = .0008); low CD4− iNKT-cell dose was associated with a relative risk of grade II-IV aGVHD of 4.27 (P = .0023; 95% CI, 1.68-10.85). Consistent with a role of iNKT cells in regulating aGVHD, in mixed lymphocyte reaction assays, CD4− iNKT cells effectively suppressed T-cell proliferation and IFN-γ secretion in a contact-dependent manner. In conclusion, higher doses of CD4− iNKT cells in PBSC grafts are associated with protection from aGVHD. This effect could be harnessed for prevention of aGVHD.

Effect of Graft and Early Posttransplantation Invariant Natural Killer T Cells on Disease Relapse Post Allogeneic Hematopoeitic Cell Transplantation

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3823-3823
Author(s):  
Sauvi chang-Fong ◽  
Kristin Rathmann ◽  
Julie Pepe ◽  
Yasser Khaled ◽  
Alicja J Copik ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Inkt Cell ◽  
Unrelated Donor ◽  
Inkt Cells ◽  
Cell Product ◽  
Cell Dose ◽  
Matched Sibling ◽  
Invariant Natural Killer ◽  
Donor Source

Abstract Invariant natural killer cells are immunomodulatory T cells with a proven effect in Graft versus Host disease. Recent data have shown that the infused iNKT cell dose is associated with decreased risk of aGVHD in matched sibling graft recipients. This study was conducted to assess the effect of the infused iNKT cell dose and early INKT recover at day 30 and 60 post HCT on relapse and GVHD. We also assessed the effect of INKT cells among patients receiving thymoglobulin as part of their HCT protocol. Methods: 48 adult allogeneic HCT recipients were enrolled on a single arm prospective trial between 2012 and 2014. All donors were mobilized with G-CSF per institutional and NMDP guidelines. Conditioning regimen consisted of Flu/Bu4 in the myeloablative setting and flu/Bu2 in RIC setting. Thymoglobulin at 1.5mg/kg/day x3 days was used for unrelated donor recipients. A small portion (2.5mL) of the donor peripheral blood stem cell product was collected prior to transplant and recipient peripheral blood (~10 mL) was collected on days +30, and +60 post HCT. Flow cytometric analysis was performed on the samples with an antibody cocktail that contained the following pre-conjugated monoclonal antibodies: CD56-PE (Miltenyi Biotech, Auburn, CA), CD3-APC, CD16-FITC, (Beckman Coulter, Brea, CA), CD19-PE-CY7 (BD Biosciences, San Jose, CA). For iNKT analysis and for CD4/CD8 analysis, 2 x 106 total cells were stained with CD3-APC, TCR Vα24-PE, TCR Vβ11-FITC (Beckman Coulter), CD4-APC-H7 and CD8-PE-CY7 (BD Biosciences). Data were acquired using BD FACSCanto II and analyzed with the FACSDiva software (BD Biosciences) to quantify CD3+ T cells, CD3+ CD56+ NK-like T cells, CD56+ CD16+ and CD56+ CD16- NK cells as well as CD19+ B cells. INKTs were quantified as CD3+, TCR Vα+, TCR Vβ+ lymphocytes. A total of 30,000 lymphocytes were collected for NK, T, and Bcell analysis. For iNKT, an end point of 200 iNKT or 500,000 total events was set. The graft and early cell subsets were assessed for their impact on acute GVHD and relapse. Results: 48 patients with a median age of 55 years received Flu/Bu4 (n= 29) and Flu/Bu2 (n=19). Donor source was a matched sibling (n=13, 27%) or a matched unrelated donor (n=35, 73%). The collected and infused graft cell doses are shown in table 1. Median time to Neutrophil and platelet engraftment was 11.5 and 18.8 days respectively. The propability of one year survival was 76% with a 1 year cumulative incidence of relapse of 34%. The pre-transplant parameters that predicted a more robust iNKT cell recovery by multivariate analysis were young recipient age, young donor age, dose of CD34 infused and RIC regimen (p<0.02 for all). A multivariate analysis to assess predictors of relapse showed that RIC (p=0.002), older donor age (p=0.03), and a smaller dose of infused INKT (p=0.012) were all significantly correlated with higher relapse rates. Day 30 and day 60 absolute iNKT and iNKT/T cell ratios were not predictors of relapse. None of the 22 patients with iNKT/T ratio of >10-3developed CMV reactivation. Conclusion: The infused iNKT cell dose in the peripheral graft inversely affects relapse rates post allogeneic HCT. This effect is independent of thymoglobulin use or donor source. Trials aiming at expanding the INT cell population in the infused grafts may help decrease risk of relapse post HCT. Table 1: Cellular Content of the Infused Graft Cell Subset Mean ± sd Median (min-max) CD3/kg infused 250 ± 111 251 (23-428) CD 34 infused 6.2 ± 2.1 6.0 (1.9-13.5) NK cell x106/kg infused 9.5 ± 11.0 6.6 (0-67) T cell x106/kg infused 192 ± 102 187 (0-516) B cell x106/kg infused 39.8 ± 33 35 (0-151) NKT x106/kg infused 9.5 ± 11.0 6.6 (0 -67) iNKT x106/kg infused 0.43 ± 0.7 0.23 (0-4.6) %CD34 product 0.99 ± 0.5 0.89 (0.15-2.7) %NK product 2.4 ± 1.5 1.9 (0.19-6.5) %T cell product 27.0 ± 11.0 27 (1.21-51.8) %NKT product 1.3 ± 1.2 1.0 (0.5- 5.9) %iNKT product 0.26 ± 0.7 0.12 (0 -4.5) %B cell product 5.4 ± 3.8 4.5 (0 -19.7) %WBC product 236 ± 100 209 (115-508) % Lymph product 32.4 ± 10.3 32 (13-51.8) NK cells, T cell, NKT and B cells are percentage of total nucleated cells iNKT cells are percentage of CD3+ cells Disclosures No relevant conflicts of interest to declare.

scholarly journals Combination of NKT14m and Low Dose IL-12 Promotes Invariant Natural Killer T Cell IFN-γ Production and Tumor Control

2020 ◽  
Vol 21 (14) ◽  
pp. 5085
Author(s):  
Peng Guan ◽  
Robert Schaub ◽  
Kim E. Nichols ◽  
Rupali Das
Keyword(s):  
T Cell ◽  
Natural Killer ◽  
Low Dose ◽  
Inkt Cell ◽  
Tumor Control ◽  
Inkt Cells ◽  
Ifn Γ ◽  
Invariant Natural Killer ◽  
Natural Killer T

Invariant natural killer T (iNKT) cells are innate-like T lymphocytes characterized by the expression of an invariant T cell receptor (iTCR) that recognizes glycolipid antigens presented by the MHC I-like CD1d molecule. Following antigenic stimulation, iNKT cells rapidly produce large amounts of cytokines that can trans-activate dendritic cells (DC) and promote the anti-tumor functions of cytotoxic lymphocytes, such as natural killer (NK) and CD8 T cells. Additionally, iNKT cells can mediate robust and direct cytotoxicity against CD1d+ tumor targets. However, many tumors down-regulate CD1d and evade iNKT cell attack. To circumvent this critical barrier to iNKT cell anti-tumor activity, a novel monoclonal antibody (mAb), NKT14 has been recently developed. This agonistic antibody binds directly and specifically to the iTCR of murine iNKT cells. In the current study, we demonstrate that NKT14m mediates robust activation, cytokine production and degranulation of murine iNKT cells, in vitro. Consistently, NKT14m also promoted iNKT cell activation and immunomodulatory functions, in vivo. Finally, administration of NKT14m with low dose interleukin (IL)-12 further augmented iNKT cell IFN-γ production in vivo, and this combination conferred superior suppression of tumor cell growth compared to NKT14m or IL-12 alone. Together, these data demonstrate that a combination treatment consisting of low dose IL-12 and iTCR-specific mAb may be an attractive alternative to activate iNKT cell anti-tumor functions.

scholarly journals Mitochondrial metabolism is essential for invariant natural killer T cell development and function

2021 ◽  
Vol 118 (13) ◽  
pp. e2021385118
Author(s):  
Xiufang Weng ◽  
Amrendra Kumar ◽  
Liang Cao ◽  
Ying He ◽  
Eva Morgun ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Natural Killer ◽  
Cell Development ◽  
Mitochondrial Metabolism ◽  
Inkt Cell ◽  
Inkt Cells ◽  
And Function ◽  
Invariant Natural Killer

Conventional T cell fate and function are determined by coordination between cellular signaling and mitochondrial metabolism. Invariant natural killer T (iNKT) cells are an important subset of “innate-like” T cells that exist in a preactivated effector state, and their dependence on mitochondrial metabolism has not been previously defined genetically or in vivo. Here, we show that mature iNKT cells have reduced mitochondrial respiratory reserve and iNKT cell development was highly sensitive to perturbation of mitochondrial function. Mice with T cell-specific ablation of Rieske iron-sulfur protein (RISP; T-Uqcrfs1−/−), an essential subunit of mitochondrial complex III, had a dramatic reduction of iNKT cells in the thymus and periphery, but no significant perturbation on the development of conventional T cells. The impaired development observed in T-Uqcrfs1−/− mice stems from a cell-autonomous defect in iNKT cells, resulting in a differentiation block at the early stages of iNKT cell development. Residual iNKT cells in T-Uqcrfs1−/− mice displayed increased apoptosis but retained the ability to proliferate in vivo, suggesting that their bioenergetic and biosynthetic demands were not compromised. However, they exhibited reduced expression of activation markers, decreased T cell receptor (TCR) signaling and impaired responses to TCR and interleukin-15 stimulation. Furthermore, knocking down RISP in mature iNKT cells diminished their cytokine production, correlating with reduced NFATc2 activity. Collectively, our data provide evidence for a critical role of mitochondrial metabolism in iNKT cell development and activation outside of its traditional role in supporting cellular bioenergetic demands.

scholarly journals Circulating Invariant Natural Killer T Cell Subsets Are Functionally Preserved in Splenectomized Children with Sickle Cell Disease Compared to Patients with Large Spleen

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3389-3389
Author(s):  
Mohamed-Rachid Boulassel ◽  
Abeer Al-Zubaidi ◽  
Ismail Beshlawi ◽  
Zahra Al-Qarni ◽  
Nidaa Al-Naamany ◽  
...  
Keyword(s):  
Steady State ◽  
T Cell ◽  
Sickle Cell Disease ◽  
Natural Killer ◽  
Sickle Cell ◽  
Study Groups ◽  
Inkt Cell ◽  
Cell Disease ◽  
Inkt Cells ◽  
Invariant Natural Killer

Abstract Recent data suggests that invariant natural killer T (iNKT) cells, a unique subset of T lymphocytes that express markers characteristic of both T cells and natural killer cells, play a pivotal role in the pathogenesis of sickle cell disease (SCD). Indeed, these cells are being considered as a potential target to prevent or treat acute crises of SCD in adult patients. However, the phenotypic and functional characteristics of circulating iNKT cell subsets in children with SCD remain unknown. Herein, we functionally evaluated iNKT cell subsets in relation to myeloid dendritic (mDC) and plasmacytoid dendritic (pDC) cells and markers of SCD severity in well-defined groups of children with SCD. The classification criteria for SCD was based on the history of patients, clinical examination, hematological and radiological findings. Blood iNKT cell subsets were prospectively studied in 68 children with SCD and normal controls using peripheral blood mononuclear cells, 10-color flow cytometry and culture assays. The iNKT cell subsets were identified by the positive-staining of Vα24Jα18 T cell receptor alpha chain, along with CD3, CD4 and CD8 surface markers and the intra-cellular cytokine production of interferon-gamma (Th1-like), interleukin-4 (Th2-like) and interleukin-17 (Th17-like) cells. The mDC and pDC cells were phenotypically characterized by the expression of HLA-DR, CD123, CD11c, Lin and CD1d, a non-classical molecule that induces the activation of iNKT cells. SCD patients were stratified into three groups including surgically splenectomized (n=23), large spleen (n=21) and steady state (n=24). Comparisons among study groups were performed using ANOVA and unpaired t test, while the Spearman's correlation was used to assess associations. Compared to normal individuals, splenectomized and steady state subjects, large spleen patients exhibited significantly higher levels of CD3iNKT, CD4iNKT and CD8iNKT cells (P=0.04). There were no differences in the levels of iNKT cell subsets between splenectomized and steady state subjects (P=0.56). The levels of mDC and pDC cells were also similar among the study groups (P=0.70). Interestingly, the large spleen patients tend to have higher CD4, but not CD8, Th1-like, Th2-like and Th17-like iNKT cells compared to splenectomized and steady state subjects (p=0.08). The expression levels of CD1d on both mDC and pDC were equivalent among study groups. The levels of CD3iNKT cells were negatively associated with baseline haemoglobin F levels (r=0.45, P=0.04) but not with age, time since splenectomy, spleen size or total hemoglobin levels at phlebotomy. Collectively, these results further advance the functional characterization of circulating iNKT cell subsets in children with SCD and reveal that surgically splenectomized patients have preserved function of iNKT cell subsets that are to be considered for clinical purposes. Disclosures No relevant conflicts of interest to declare.

scholarly journals Exogenous Activation of Invariant Natural Killer T Cells by α-Galactosylceramide Reduces Pneumococcal Outgrowth and Dissemination Postinfluenza

mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Adeline Barthelemy ◽  
Stoyan Ivanov ◽  
Maya Hassane ◽  
Josette Fontaine ◽  
Béatrice Heurtault ◽  
...  
Keyword(s):  
Mouse Model ◽  
Influenza A Virus ◽  
Bacterial Pneumonia ◽  
Influenza A ◽  
Bacterial Infections ◽  
Pneumococcal Infection ◽  
Clinical Development ◽  
Inkt Cell ◽  
Inkt Cells ◽  
Invariant Natural Killer

ABSTRACT Influenza A virus infection can predispose to potentially devastating secondary bacterial infections. Invariant natural killer T (iNKT) cells are unconventional, lipid-reactive T lymphocytes that exert potent immunostimulatory functions. Using a mouse model of postinfluenza invasive secondary pneumococcal infection, we sought to establish whether α-galactosylceramide (α-GalCer [a potent iNKT cell agonist that is currently in clinical development]) could limit bacterial superinfection. Our results highlighted the presence of a critical time window during which α-GalCer treatment can trigger iNKT cell activation and influence resistance to postinfluenza secondary pneumococcal infection. Intranasal treatment with α-GalCer during the acute phase (on day 7) of influenza virus H3N2 and H1N1 infection failed to activate (gamma interferon [IFN-γ] and interleukin-17A [IL-17A]) iNKT cells; this effect was associated with a strongly reduced number of conventional CD103 + dendritic cells in the respiratory tract. In contrast, α-GalCer treatment during the early phase (on day 4) or during the resolution phase (day 14) of influenza was associated with lower pneumococcal outgrowth and dissemination. Less intense viral-bacterial pneumonia and a lower morbidity rate were observed in superinfected mice treated with both α-GalCer (day 14) and the corticosteroid dexamethasone. Our results open the way to alternative (nonantiviral/nonantibiotic) iNKT-cell-based approaches for limiting postinfluenza secondary bacterial infections. IMPORTANCE Despite the application of vaccination programs and antiviral drugs, influenza A virus (IAV) infection is responsible for widespread morbidity and mortality (500,000 deaths/year). Influenza infections can also result in sporadic pandemics that can be devastating: the 1918 pandemic led to the death of 50 million people. Severe bacterial infections are commonly associated with influenza and are significant contributors to the excess morbidity and mortality of influenza. Today’s treatments of secondary bacterial (pneumococcal) infections are still not effective enough, and antibiotic resistance is a major issue. Hence, there is an urgent need for novel therapies. In the present study, we set out to evaluate the efficacy of α-galactosylceramide (α-GalCer)—a potent agonist of invariant NKT cells that is currently in clinical development—in a mouse model of postinfluenza, highly invasive pneumococcal pneumonia. Our data indicate that treatment with α-GalCer reduces susceptibility to superinfections and, when combined with the corticosteroid dexamethasone, reduces viral-bacterial pneumonia.

scholarly journals Cancer Immunotherapeutic Potential of NKTT320, a Novel, Invariant, Natural Killer T Cell-Activating, Humanized Monoclonal Antibody

2020 ◽  
Vol 21 (12) ◽  
pp. 4317 ◽  
Author(s):  
Nishant P. Patel ◽  
Peng Guan ◽  
Devika Bahal ◽  
Tanwir Hashem ◽  
Felix Scheuplein ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
T Cell ◽  
Natural Killer ◽  
Cell Activation ◽  
Cell Receptor ◽  
Inkt Cell ◽  
Humanized Monoclonal Antibody ◽  
Cancer Immunotherapeutic ◽  
Invariant Natural Killer ◽  
Natural Killer T

Invariant natural killer T cells (iNKTs) directly kill tumor cells and trans-activate the anti-tumor functions of dendritic cells (DC), natural killer (NK) cells, and T and B cells. As such, iNKTs serve as a powerful tool for use in cell-based cancer immunotherapy. iNKT cell activation commonly requires engagement of the invariant T cell receptor (iTCR) by CD1d presenting glycolipid antigens. However, transformed cells often down-regulate CD1d expression, which results in a reduction of iNKT cell anti-tumor functions. One approach to circumvent this critical barrier to iNKT cell activation is to develop an agonistic antibody that binds directly to the iTCR without the requirement for CD1d-mediated antigen presentation. To this end, we have characterized the iNKT cell stimulatory properties of NKTT320, a novel, recombinant, humanized, monoclonal antibody that binds selectively and with high affinity to human iTCRs. Strikingly, immobilized NKTT320 mediated robust iNKT cell activation (upregulation of CD25 and CD69) and proliferation (carboxyfluorescein succinimidyl ester (CFSE) dilution), as well as Th1 and Th2 cytokine production. Additionally, iNKTs stimulated by plate-bound NKTT320 exhibited increased intracellular levels of granzyme B and degranulation (exposure of CD107 on the cell surface). Furthermore, both soluble and immobilized NKTT320 induced iNKT cell-mediated activation of bystander immune cells, suggesting that this novel anti-iTCR antibody facilitates both direct and indirect iNKT cell cytotoxicity. These studies are significant, as they provide a framework by which iNKT cell anti-cancer functions could be enhanced for therapeutic purposes.

scholarly journals License to Kill: When iNKT Cells Are Granted the Use of Lethal Cytotoxicity

2020 ◽  
Vol 21 (11) ◽  
pp. 3909
Author(s):  
Angélica Díaz-Basabe ◽  
Francesco Strati ◽  
Federica Facciotti
Keyword(s):  
Immune Responses ◽  
Inkt Cell ◽  
Cell Cytotoxicity ◽  
Future Perspectives ◽  
Inkt Cells ◽  
Cytotoxic Potential ◽  
Lipid Antigens ◽  
Cancer Immunotherapies ◽  
Cluster Of Differentiation ◽  
Invariant Natural Killer

Invariant Natural Killer T (iNKT) cells are a non-conventional, innate-like, T cell population that recognize lipid antigens presented by the cluster of differentiation (CD)1d molecule. Although iNKT cells are mostly known for mediating several immune responses due to their massive and diverse cytokine release, these cells also work as effectors in various contexts thanks to their cytotoxic potential. In this Review, we focused on iNKT cell cytotoxicity; we provide an overview of iNKT cell subsets, their activation cues, the mechanisms of iNKT cell cytotoxicity, the specific roles and outcomes of this activity in various contexts, and how iNKT killing functions are currently activated in cancer immunotherapies. Finally, we discuss the future perspectives for the better understanding and potential uses of iNKT cell killing functions in tumor immunosurveillance.

Inhibition of Lymphocyte Trafficking Using a CCR5 Antagonist – Final Results of a Phase I/II Study

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1011-1011 ◽  
Author(s):  
Ran Reshef ◽  
Selina M. Luger ◽  
Elizabeth O. Hexner ◽  
Alison W. Loren ◽  
Noelle V. Frey ◽  
...  
Keyword(s):  
T Cell ◽  
Hiv Infection ◽  
Phase I ◽  
Research Funding ◽  
Acute Gvhd ◽  
Lymphocyte Trafficking ◽  
Comparator Group ◽  
Gvhd Prophylaxis ◽  
Grade Iii

Abstract Abstract 1011 Inhibition of lymphocyte trafficking early after allogeneic stem cell transplantation (SCT) may prevent GvHD without interfering with GvL activity. Animal models and genomic data in humans indicate that the interaction between CCR5 and its ligands CCL3, CCL4 and RANTES is pivotal in the pathogenesis of GvHD. Maraviroc (MVC; Selzentry®, Pfizer) is the first oral CCR5 antagonist in clinical use. The antiviral properties of MVC in HIV infection are known, but its effects on chemotaxis and immune function in patients without HIV infection have not been explored. We hypothesized that CCR5 inhibition early after allogeneic SCT would reduce lymphocyte chemotaxis and result in low rates of acute GvHD without impairing engraftment or antitumor activity. In vitro, MVC effectively and specifically inhibited CCR5 internalization and reduced RANTES-induced chemotaxis in concentrations achievable in humans, recapitulating a defect observed in homozygotes for the del32-CCR5 polymorphism. MVC had no effect on hematopoietic colony formation, T-cell mediated cytotoxicity and T-cell proliferation. Between May 2009 and March 2011, we enrolled 38 pts in a phase I/II study of reduced intensity conditioned (RIC) allogeneic SCT. Patients had high-risk features by age (median=62, range 21–74), donor source (matched related 34%, matched unrelated 50%, single-antigen mismatch 16%) and comorbidities (comorbidity index: low 55%, intermediate 34%, high 11%). Underlying diseases were AML (15), MDS (6), NHL (8), myelofibrosis (4), aplastic anemia, myeloma, CLL, Hodgkin, CML (1 each). Pts received fludarabine 120mg/m2 and IV busulfan 6.4 mg/kg followed by peripheral blood stem cells. In addition to standard GvHD prophylaxis with tacrolimus and methotrexate, MVC was given from day −2 to +30. Pharmacokinetic analysis on the first 13 pts identified 300 mg bid as the appropriate dose (Reshef, ASH 2010). MVC was well tolerated, and adverse events were similar to the expected toxicity observed in patients undergoing RIC SCT. The median time to ANC>500/μL was 15 d (range 10–27) and to platelets>20k/μL was 19 d (range 9–84). The median whole blood and T-cell donor chimerism at day 100 was 96.5% (range 0–100%) and 85% (range 0–100%) respectively. Median follow-up was 200 days (range 12–760). Among 35 evaluable patients, the cumulative incidences of any acute GvHD and grade III–IV acute GvHD at day 100 were 14.7 ± 6.2% and 2.9 ± 2.9%, respectively. Importantly, in the first 100 days, there were no cases of acute GvHD involving the liver or gut. At day 180, the rate of acute GvHD was 20.7 ± 7.1%, largely confined to the skin with low rates of GvHD in the liver (3 ± 3%) and gut (7.4 ± 5.3%). In evaluable pts who received a graft from their HLA-matched sibling (11), there was no GvHD before day 100 and only two cases of acute GvHD before day 180. We compared these results to a cohort of 38 well-matched consecutive patients treated at our institution with RIC SCT using an identical regimen but without MVC between 2009 and 2011. We observed a similar incidence of acute GvHD (all grades) at day 100 (14.7 ± 6.2 vs. 16 ± 6.1%; P=0.88), but a 64% decrease in the MVC group at day 180 (20.7 ± 7.1 vs. 45.4 ± 9%; P=0.03). The incidence rates of severe GvHD (grade III–IV) were 2.9 ± 2.9% in the MVC group vs. 5.5 ± 3.8% in the comparator group at day 100 (P=0.59) and 6.5 ± 4.5% vs. 18.1 ± 6.8% at day 180 (P=0.15). Treatment-related mortality in pts receiving MVC was low. At 1 year, non-relapse mortality rate was 7.6 ± 5.5% (control group: 15.7 ± 6.6%; P=0.35). Infectious complications were seen at a rate that is expected with RIC SCT. Recovery of lymphocyte counts and lymphocyte subsets was not impaired by MVC. We evaluated whether a protective effect against GvHD was associated with an increase in relapse. In the MVC group, the incidence of relapse was 34.2 ± 8.8% at day 180; this was not significantly different from the comparator group (43.9 ± 8.8%, P=0.44), implying preservation of the graft-versus-tumor effect with MVC. Rates of overall survival and relapse-free survival were similar in both groups. Pharmacodynamic testing revealed that sera from patients taking MVC prevented CCR5 internalization by RANTES and blocked T-cell chemotaxis in vitro, providing evidence for in vivo biological activity and supporting the hypothesized mechanism of action. In summary, inhibition of lymphocyte trafficking is a novel, specific and potentially effective strategy to reduce the incidence of acute GvHD. Disclosures: Off Label Use: Use of maraviroc in GvHD prophylaxis will be discussed. Frey:Pfizer: Speakers Bureau. Vonderheide:Pfizer: Research Funding. Porter:Pfizer: Research Funding.

Sign in / Sign up

Export Citation Format

Share Document