scholarly journals Mechanisms of Dysregulated Humoral and Cellular Immunity by SARS-CoV-2

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1027
Author(s):  
Nima Taefehshokr ◽  
Sina Taefehshokr ◽  
Bryan Heit
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Adaptive Immune Response ◽  
Neutralizing Antibody ◽  
Humoral And Cellular Immunity ◽  
Cell Responses ◽  
Adaptive Immune ◽  
Antibody Titers

The current coronavirus disease 2019 (COVID-19) pandemic, a disease caused by severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), was first identified in December 2019 in China, and has led to thousands of mortalities globally each day. While the innate immune response serves as the first line of defense, viral clearance requires activation of adaptive immunity, which employs B and T cells to provide sanitizing immunity. SARS-CoV-2 has a potent arsenal of mechanisms used to counter this adaptive immune response through processes, such as T cells depletion and T cell exhaustion. These phenomena are most often observed in severe SARS-CoV-2 patients, pointing towards a link between T cell function and disease severity. Moreover, neutralizing antibody titers and memory B cell responses may be short lived in many SARS-CoV-2 patients, potentially exposing these patients to re-infection. In this review, we discuss our current understanding of B and T cells immune responses and activity in SARS-CoV-2 pathogenesis.

TAA/ecdCD40L VPP Vaccination Induces Robust Adaptive Immune Response Even in Individuals with Post Transplantation Lymphopenia

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 363-363 ◽  
Author(s):  
Tae Hae Han ◽  
Yucheng Tang ◽  
Yeon Hee Park ◽  
Jonathan Maynard ◽  
Pingchuan Li ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Cell Line ◽  
Adaptive Immune Response ◽  
Helper T Cells ◽  
Leukemia Cell Line ◽  
Adaptive Immune ◽  
Cd40l Expression ◽  
Robust Adaptive

Abstract Individuals of advanced chronological age exhibit an impaired immune response to vaccines. This may be due to a reduction in the ratio of antigen naïve/memory CD4 and CD8 T cells and acquisition of functional defects in activated “helper” CD4 T cells (eg diminished CD40 ligand (CD40L) expression) during the aging process. The absence of the CD40L on activated CD4 helper T cells reduces the magnitude of expansion of antigen specific T and B cells induced by vaccination. In order to circumvent this defective response to vaccines among individuals in the fifth and sixth decades of life, our laboratory has developed an adenoviral vector (Ad-sig-TAA/ecdCD40L) vaccine which is designed to overcome the absence of CD40L expression in activated CD4 helper T cells in older individuals. The subcutaneous (sc) injection of this vector leads to the release of a fusion protein composed of a TAA linked to the extracellular domain (ecd) of the CD40L, which binds to the CD40 receptor on DCs, activates the DCs, and leads to the presentation of TAA fragments on Class I MHC. Two sc injections of the TAA/ecdCD40L protein as a booster following the sc administration of the Ad-sig-TAA/ecdCD40L vector (we call this the TAA/ecdCD40L VPP vaccine) expands the magnitude of the cellular and humoral immune response induced by the vector in 18 month old aged mice as well as in younger mice. In order to explore ways of further amplifying the immune response induced by this vaccine, we decided to test the feasibility of using this vaccine following treatments which reduce the number of T cells in the body of the test subject. We hypothesized that during states of chemotherapy or radiation induced lymphopenia, the number of negative regulatory CD4CD25FoxP3 T cells would be reduced, and all of the regulatory signals in the T cell compartment would be promoting expansion of T cells, thus creating an ideal state for vaccination. To test this hypothesis, we injected 100,000 cells from an established neoplastic cell line sc. Three days later, we administered myeloablative doses of total body irradiation (TBI) followed by a T cell depleted syngeneic bone marrow transplant (TCDBMT) to reconstitute neutrophil and platelet production. Three days following the TBI and TCDBMT, we intravenously infused donor lymphocytes (DLI) from a TAA/ ecdCD40L VPP vaccinated syngeneic donor. Four weeks later, we vaccinated the recipient mouse further with TAA/ecdCD40L sc injections. We tested this for a TAA composed of a junctional peptide from the p210Bcr-Abl protein of chronic myelogenous leukemia (CML) and for the E7 protein of the human papilloma virus (HPV). We found that in the case of the BcrAbl/ecdCD40L VPP vaccine, 50% of the mice treated with TBI, TCDBMT, ten million lymphocytes (DLI) from BcrAbl/ecdCD40L VPP vaccinated syngeneic donors followed in 4 weeks by 3 BcrAbl/ecdCD40L protein sc injections of the recipient test mouse, developed a complete response with the vaccination and that these mice remained disease free beyond 250 days after injection of the P210Bcr-Abl positive 32D leukemia cells, whereas C56BL/6J test mice treated with TBI and TCDBMT without DLI from vaccinated donors nor sc BcrAbl/ecdCD40L sc booster vaccination following injection with the p210Bcr-Abl positive 32D myeloid leukemia cell line all died by day 32. Mice treated with TBI, TCDBMT, DLI from unvaccinated donors followed by vaccination of the recipient with 3 sc BcrAbl/ecdCD40L protein injections exhibited a degree of leukemia suppression that was equal to mice receiving TBI, TCDBMT, DLI from a BcrAbl/ecdCD40L VPP vaccinated donor and BcrAbl/ecdCD40L vaccination. To test the effect of the TAA/ecdCD40L VPP vaccine against an antigen associated with an epithelial neoplasm, we injected 100,000 E7 positive TC-1 mouse cancer cells into syngeneic C57BL6J mice followed in 3–5 days by myeloablative doses of TBI and engrafting doses of TCDBMT. Three days later, the mice received 10 million spleen cells from syngeneic donor mice previously vaccinated with the E7/ecdCD40L VPP vaccine. Finally, 4 weeks later, the test mice received sc E7/ecdCD40L protein booster injections. The vaccinated mice achieved much greater degrees of tumor suppression than was seen following TBI and TCDBMT without DLI from vaccinated donors. These studies show that it is possible to induce a robust adaptive immune response by vaccination with the TAA/ecdCD40L VPP vaccine even in severely lymphopenic individuals.

Immunomodulatory Effects and Adaptive Immune Response to Daratumumab in Multiple Myeloma

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3037-3037 ◽  
Author(s):  
Jakub Krejcik ◽  
Tineke Casneuf ◽  
Inger Nijhof ◽  
Bie Verbist ◽  
Jaime Bald ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Research Funding ◽  
Immune Cell ◽  
Adaptive Immune Response ◽  
Advisory Committees ◽  
Adaptive Immune ◽  
T Cell Clonality ◽  
Cell Clonality

Abstract Introduction: Daratumumab (DARA) is a novel human monoclonal antibody that targets CD38, a protein that is highly expressed on multiple myeloma (MM) cells. DARA acts through multiple immune effector-mediated mechanisms, including complement-dependent cytotoxicity, antibody-dependent cell-mediated cytotoxicity, and antibody-dependent cellular phagocytosis. In two clinical studies (NCT00574288 [GEN501] and NCT01985126 [Sirius]) of DARA monotherapy in patients with relapsed and refractory MM, overall response rates were 36% and 29%, respectively. CD38 is highly expressed in myeloma cells but also expressed in lymphocytes and other immune cell populations. Therefore, the effects of DARA on immune cell populations and adaptive immune response pathways were investigated. Methods: The patient population investigated included treated subjects with MM that were relapsed after or were refractory to ≥2 prior therapies (GEN501) or had received ≥3 prior therapies, including a proteasome inhibitor (PI) and an immunomodulatory drug (IMiD), or were refractory to both a PI and an IMiD (Sirius). Patients assessed in this analysis were treated with 16 mg/kg DARA. When both studies were combined, median age (range) was 64 (31-84) years and median time from diagnosis was 5.12 (0.77-23.77) years. Seventy-six percent of patients had received >3 prior therapies and 91% were refractory to their last treatment. Clinical response was evaluated using IMWG consensus recommendations. Peripheral blood (PB) samples and bone marrow (BM) biopsies/aspirates were taken at prespecified time points and immunophenotyped by flow cytometry to enumerate various T-cell sub-types. T-cell clonality was measured by TCR sequencing. Antiviral T-cell response and regulatory T-cell (Treg) activity were analysed by functional in vitro assays. T-cell subpopulation counts were modelled over time with linear mixed modelling. Two group comparisons were performed using non-parametric Wilcoxon rank sum tests. Results: Data from 148 patients receiving 16 mg/kg DARA in GEN501 (n = 42) and Sirius (n = 106) were analyzed for changes in immune response. In PB, robust mean increases in CD3+ (44%), CD4+ (32%) and CD8+ (62%) T-cell counts per 100 days were seen with DARA treatment. However, responding evaluable patients (n = 45) showed significantly greater increases from baseline than nonresponders (n = 93) in CD3+ (P = 0.00012), CD4+ (P = 0.00031), and CD8+ (P = 0.00018) T cells. In BM aspirates the number of CD3+, CD4+, and CD8+ T-cells increased during treatment compared to baseline (the median percent increases were 19.95%, 5.66%, and 26.99% [n = 58]). Additionally, CD8+: CD4+ T-cell ratios significantly increased compared to baseline in both PB (P = 0.00017), and BM (P = 0.00016). T cell clonality, assessed by TCR sequencing, increased after DARA treatment compared with pretreatment (P = 0.049), with greater sums of absolute expansion in the repertoire (P = 0.037), as well as greater maximum expansion of a single clone (P = 0.048) in responders compared to nonresponders. Increased antiviral T-cell responses were observed post-DARA treatment, particularly in responders. Interestingly, a novel subpopulation of regulatory T cells was identified that expressed high levels of CD38. These cells comprised ~10% of all Tregs and were depleted by one DARA infusion. In ex vivo analyses, CD38+ Tregs appeared to be highly immune suppressive compared to CD38-Tregs. Conclusions: Robust T cell increases, increased CD8+: CD4+ ratios, increased antiviral responses, and increased T cell clonality were all observed after DARA treatment in a heavily pretreated, relapsed, and refractory patient population not expected to have strong immune responses. Improved clinical responses were associated with changes in these parameters. In addition, a sub-population of regulatory T cells expressing high CD38 levels was determined to be extremely immune suppressive and sensitive to DARA treatment. These data suggest a previously unknown immune modulatory role of DARA that may contribute to its efficacy, and a potential role for CD38 immune targeted therapies. We postulate that there are several distinct and complementary mechanisms that contribute to DARA's efficacy including increased antigen presentation through phagocytosis, targeting of immune suppressive Tregs, and increased adaptive immune responses. JK and TC contributed equally to this work. Disclosures Casneuf: Janssen: Employment. Verbist:Janssen: Employment. Bald:Janssen: Employment. Plesner:Genmab: Membership on an entity's Board of Directors or advisory committees; Roche and Novartis: Research Funding; Janssen and Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding. Liu:Janssen: Employment. van de Donk:Janssen Pharmaceuticals: Research Funding; Amgen: Research Funding; Celgene: Research Funding. Weiss:Janssen and Onclave: Research Funding; Janssen and Millennium: Consultancy. Ahmadi:Janssen: Employment. Lokhorst:Genmab: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Amgen: Honoraria. Mutis:Janssen: Research Funding; Genmab: Research Funding.

scholarly journals Orchestration of Adaptive T Cell Responses by Neutrophil Granule Contents

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Danielle Minns ◽  
Katie Jane Smith ◽  
Emily Gwyer Findlay
Keyword(s):  
Immune Response ◽  
Immune System ◽  
T Cell ◽  
Innate Immune System ◽  
Adaptive Immune Response ◽  
Innate Immune ◽  
T Cell Immunity ◽  
Cell Responses ◽  
Adaptive Immune ◽  
Cell Immunity

Neutrophils are the most abundant leukocytes in peripheral blood and respond rapidly to danger, infiltrating tissues within minutes of infectious or sterile injury. Neutrophils were long thought of as simple killers, but now we recognise them as responsive cells able to adapt to inflammation and orchestrate subsequent events with some sophistication. Here, we discuss how these rapid responders release mediators which influence later adaptive T cell immunity through influences on DC priming and directly on the T cells themselves. We consider how the release of granule contents by neutrophils—through NETosis or degranulation—is one way in which the innate immune system directs the phenotype of the adaptive immune response.

scholarly journals Sustained IL-15 response signature predicts RhCMV/SIV vaccine efficacy

2021 ◽  
Author(s):  
Fredrik Barrenäs ◽  
Scott G. Hansen ◽  
Lynn Law ◽  
Connor Driscoll ◽  
Richard R. Green ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Cell Function ◽  
Effector Memory ◽  
Highly Pathogenic ◽  
Cell Responses ◽  
Adaptive Immune ◽  
Immune Pathways

AbstractSimian immunodeficiency virus (SIV) challenge of rhesus macaques (RMs) vaccinated with Rhesus Cytomegalovirus (RhCMV) vectors expressing SIV proteins (RhCMV/SIV) results in a binary outcome: stringent control and subsequent clearance of highly pathogenic SIV in ~55% of vaccinated RMs with no protection in the remaining 45%. Although previous work suggests that unconventionally restricted, SIV-specific, effector-memory (EM)-biased CD8+ T cell responses are necessary for efficacy, the magnitude of these responses does not predict efficacy, and the basis of protection vs. non-protection in RhCMV/SIV vector-vaccinated RMs has not been elucidated. Here, we report that RhCMV/SIV vector administration strikingly alters the whole blood transcriptome of vaccinated RMs, with the sustained induction of specific immune-related pathways, including non-canonical T cell receptor (TCR), toll-lie receptor (TLR), inflammasome/cell death, and interleukin-15 (IL-15) signaling, significantly predicting protection. The IL-15 gene expression signature was further evaluated in an independent RM IL-15 treatment cohort, revealing that in whole blood the response to IL-15 is inclusive of innate and adaptive immune gene expression networks that link with RhCMV/SIV vaccine efficacy. We also show that this IL-15 response signature similarly tracks with vaccine protection in an independent RhCMV/SIV vaccination/SIV challenge RM validation cohort. Thus, the RhCMV/SIV vaccine imparts a coordinated and persistent induction of innate and adaptive immune pathways featuring IL-15, a known regulator of CD8+ T cell function, that enable vaccine-elicited CD8+ T cells to mediate protection against highly pathogenic SIV challenge.Author SummarySIV insert-expressing vaccine vectors based on strain 68-1 RhCMV elicit robust, highly effector-memory-biased T cell responses that are associated with an unprecedented level of SIV control after challenge (replication arrest leading to clearance) in slightly over half of vaccinated monkeys. Since efficacy is not predicted by standard measures of immunogenicity, we used functional genomics analysis of RhCMV/SIV vaccinated monkeys with known challenge outcomes to identify immune correlates of protection. We found that arrest of viral replication after challenge significantly correlates with a vaccine-induced response to IL-15 that includes modulation of T cell, inflammation, TLR signaling, and cell death programming. These data suggest that RhCMV/SIV efficacy is not based on chance, but rather, results from a coordinated and sustained vaccine-mediated induction of innate and adaptive immune pathways featuring IL-15, a known regulator of CD8+ effector-memory T cell function, that enable vaccine-elicited CD8+ T cells to mediate efficacy.

scholarly journals Similar distribution of T-cell subsets in Crohn’s disease and in diverticulitis provide evidence against a primary causal role for these cells in Crohn’s

2019 ◽  
Author(s):  
Ayse U Akarca ◽  
Peter Ellery ◽  
Anthony W Segal ◽  
Teresa Marafioti
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Crohn’S Disease ◽  
T Cell ◽  
T Lymphocytes ◽  
Crohn's Disease ◽  
Adaptive Immune Response ◽  
Causal Role ◽  
Faecal Material ◽  
Adaptive Immune

AbstractBackground and AimsT lymphocytes are found in abnormally large numbers in the bowel in Crohn’s disease. This has led to the assumption by some that these cells play a causal role in the pathogenesis of what has been labelled an autoimmune disease. An alternative explanation for their presence is that, as part of the adaptive immune system, the accumulation of these cells is not a primary phenomenon, but is a secondary adaptive immune response to faecal material in the bowel wall. To distinguish between these two processes we compared the T-cell repertoire in the bowel in Crohn’s with that in diverticulitis, where the primary pathology is mechanical, with a subsequent immune response to the accumulated faecal material.MethodsSix cases of Crohn’s disease and six patients with diverticulitis were studied. Dewaxed sections of bowel were stained with Anti-CD4, Anti-CD8, Anti-FOXP3 and Anti-CD25 to identify cytotoxic T-cells, NK-Tcells; T-helper and T-reg T-cells.ResultsNo differences were found in the distribution of the different T-cell markers in either the mucosa or in areas of inflammation in the two conditions.ConclusionThe accumulation of T-lymphocytes in the bowel in Crohn’s disease is likely to be a sign of an adaptive immune response to faecal material within the bowel rather than an indication of a primary causal immune attack on the bowel that produces the disease.

SARS-CoV-2 elicits robust adaptive immune responses regardless of disease severity

2020 ◽  
Author(s):  
Stine SF Nielsen ◽  
Line K Vibholm ◽  
Ida Monrad ◽  
Rikke Olesen ◽  
Giacomo S Frattari ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Immune Responses ◽  
Disease Severity ◽  
Adaptive Immune Response ◽  
T Cell Responses ◽  
Adaptive Immune Responses ◽  
Cell Responses ◽  
Adaptive Immune ◽  
Robust Adaptive

AbstractThe SARS-CoV-2 pandemic currently prevails worldwide. To understand the immunological signature of SARS-CoV-2 infections and aid the search for treatments and vaccines, comprehensive characterization of adaptive immune responses towards SARS-CoV-2 is needed. We investigated the breadth and potency of antibody-, and T-cell immune responses, in 203 recovered SARS-CoV-2 infected patients who presented with asymptomatic to severe infections. We report very broad serological profiles with cross-reactivity to other human coronaviruses. Further, >99% had SARS-CoV-2 epitope specific antibodies, with SARS-CoV-2 neutralization and spike-ACE2 receptor interaction blocking observed in 95% of individuals. A significant positive correlation between spike-ACE2 blocking antibody titers and neutralization potency was observed. SARS-CoV-2 specific CD8+ T-cell responses were clear and quantifiable in 90% of HLA-A2+ individuals. The viral surface spike protein was identified as the dominant target for both neutralizing antibodies and CD8+ T cell responses. Overall, the majority of patients had robust adaptive immune responses, regardless of disease severity.Author summarySARS-CoV-2 can cause severe and deadly infections. However, the immunological understanding of this viral infection is limited. Currently, several vaccines are being developed to help limit transmission and prevent the current pandemic. However, basic understanding of the adaptive immune response developed during SARS-CoV-2 infections is needed to inform further vaccine development and to understand the protective properties of the developed immune response. We investigated, the adaptive immune response developed during SARS-CoV-2 infections in recovered patients experiencing a full spectrum of disease severity, from asymptomatic infections to severe cases requiring hospitalization. We used a novel multiplex serological platform, cell-based neutralization assays and dextramer flow cytometry assays to characterize a broad and robust humoral and cellular immune response towards SARS-CoV-2. We found that the vast majority of recovered individuals have clear detectable and functional SARS-CoV-2 spike specific adaptive immune responses, despite diverse disease severities. The detection of both a humoral and cellular functional spike specific immune response in the vast majority of the individuals, irrespective of asymptomatic manifestations, supports vaccine designs currently underway, and encourages further exploration of whether primary infections provide protection to reinfection.

scholarly journals Revealing the role of CD4+ T cells in viral immunity

2012 ◽  
Vol 209 (8) ◽  
pp. 1391-1395 ◽  
Author(s):  
Andrea J. Sant ◽  
Andrew McMichael
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Cd4 T Cells ◽  
Adaptive Immune Response ◽  
Neutralizing Antibody ◽  
Viral Immunity ◽  
Antigen Specificity ◽  
Viral Pathogens ◽  
Adaptive Immune

Protective immunity to chronic and acute viral infection relies on both the innate and adaptive immune response. Although neutralizing antibody production by B cells and cytotoxic activity of CD8+ T cells are well-accepted components of the adaptive immune response to viruses, identification of the specific role of CD4+ T cells in protection has been more challenging to establish. Delineating the contribution of CD4+ T cells has been complicated by their functional heterogeneity, breadth in antigen specificity, transient appearance in circulation, and sequestration in tissue sites of infection. In this minireview, we discuss recent progress in identifying the multiple roles of CD4+ T cells in orchestrating and mediating the immune responses against viral pathogens. We highlight several recent reports, including one published in this issue, that have employed comprehensive and sophisticated approaches to provide new evidence for CD4+ T cells as direct effectors in antiviral immunity.

scholarly journals Mechanisms Governing Immunotherapy Resistance in Pancreatic Ductal Adenocarcinoma

2021 ◽  
Vol 11 ◽  
Author(s):  
Zoe C. Schmiechen ◽  
Ingunn M. Stromnes
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Cell Function ◽  
Adaptive Immune Response ◽  
Ductal Adenocarcinoma ◽  
Adaptive Immune ◽  
Cell Clearance

Pancreatic ductal adenocarcinoma (PDA) is a lethal malignancy with an overall 5-year survival rate of 10%. Disease lethality is due to late diagnosis, early metastasis and resistance to therapy, including immunotherapy. PDA creates a robust fibroinflammatory tumor microenvironment that contributes to immunotherapy resistance. While previously considered an immune privileged site, evidence demonstrates that in some cases tumor antigen-specific T cells infiltrate and preferentially accumulate in PDA and are central to tumor cell clearance and long-term remission. Nonetheless, PDA can rapidly evade an adaptive immune response using a myriad of mechanisms. Mounting evidence indicates PDA interferes with T cell differentiation into potent cytolytic effector T cells via deficiencies in naive T cell priming, inducing T cell suppression or promoting T cell exhaustion. Mechanistic research indicates that immunotherapy combinations that change the suppressive tumor microenvironment while engaging antigen-specific T cells is required for treatment of advanced disease. This review focuses on recent advances in understanding mechanisms limiting T cell function and current strategies to overcome immunotherapy resistance in PDA.

scholarly journals In Vitro Comparison of Different TKI Activity in T-Cell Populations: Selective Sparing of Treg By Nilotinib

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5774-5774
Author(s):  
Elena Marinelli Busilacchi ◽  
Andrea Costantini ◽  
Nadia Viola ◽  
Benedetta Costantini ◽  
Antonella Poloni ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Cell Population ◽  
Cell Cultures ◽  
Adaptive Immune Response ◽  
Dependent Manner ◽  
Adaptive Immune

Abstract Introduction Chronic Graft Versus Host Disease (cGVHD) is a major complication of allogeneic stem-cell transplantation and is characterized by frequent multi-organ involvement that resembles the autoimmune diseases. Donor-derived CD4+ and CD8+ T lymphocytes have classically been considered to be the main effector cells mediating GVHD pathogenesis. Indeed, removal of T cells from transplant inocula almost completely prevents GVHD developing, at the price of increased incidences of graft rejection and disease recurrence. However recent studies suggest that B cells might also play an important role in the biology of cGVHD. The role of Treg lymphocytes in the pathogenesis of cGVHD is still controversial and the tyrosine kinase inhibitor′s (TKI) role in the modulation of this pathway is not yet fully characterized. In vitro data confirm that TKIs regulates both innate and adaptive immune response by interacting with many cell population such as T-cells, B-cells, dendritic cells, mast cells and macrophages. According to these observations, we investigated the TKI′s immunomodulatory effects (Nilotinib, Dasatinib, Imatinib, Ponatinib) on lymphocyte populations. Materials and Methods Peripheral blood mononuclear cells were isolated by density gradient centrifugation using Ficoll-Biocoll. Cells were cultured in RPMI 1640 at a concentration 1x106 cell/well. Nilotinib, Imatinib, Dasatinib and Ponatinib were added to cell cultures at serial concentration (Imatinib:1μM,10μM,50μM; Nilotinib:0.5μM,2μM,10μM; Dasatinib:50nM,100nM,200nM; Ponatinib:1nM,10nM,50nM,100nM) on the first day. Six-color flow cytometry analysis (Facs Canto II) was performed on the cells harvested after 96 h cultures using conjugated antibodies (CD3,CD4,CD16,CD56,CD3,CD25,CD19,CD45RA,FoxP3,CD127,7-Aminoactinomycin-D), for cell cycle analysis cells were stained with propidium iodide. For cytokine analysis, supernatants were collected and analyzed for cytokines according to the instruction of Bio-Plex Pro Human Cytokine 17-plex Assay with Bio-Plex (Bio-Rad). Results A significant decrease of cytotoxic T cells viability was observed when cells were cultured in presence of Imatinib (50μM,p<0.01), Ponatinib (10nM,p<0.05) and Dasatinib (100nM,p<0.01). On the contrary, exposure to Nilotinib didn′t induce cell death. Increasing concentrations of all the tested TKI significantly inhibited T cell proliferation in a dose-dependent manner; the effect become statistically significant starting from Imatinib (1μM,p<0.05), Dasatinib (50nM,p<0.01), Ponatinib (50nM,p<0.01) and Nilotinib (0.5μM,p<0.01). Exposure to Imatinib, Dasatinib and Ponatinib induced a statistically significant decrease (p<0.01) of Treg cells proportion, even at the lowest drug concentration in culture; Nilotinib induced Treg decrease only at concentrations exceeding 2μM (p<0.01), higher than those usually achieved in clinical practice. A significant increase of naive Treg apoptosis was observed after exposure to Dasatinib (50nmM,p<0.01), Ponatinib (50nM,p<0.01) and Imatinib (50μM,p<0.01); exposure to Nilotinib has no effect on this population. Both Nilotinib and Dasatinib induced a profound inhibition of pro-inflammatory cytokine production (in particular TNFα, IFNγ, IL13 and IL17) when added to the cell cultures (p<0.05); slower decrease in supernatant cytokine concentration was observed in presence of either Imatinib (50μM,p<0.05) and Ponatinib (50nM,p<0.05). Increasing concentrations of all TKIs except Nilotinib induced a significant decline of NK cells (p<0.01) and B cell (p<0.01). Conclusion The present study focuses the peculiar Nilotinib activity on lymphocyte′s regulation: this TKI, at therapeutic concentrations in vitro, interact with innate and adaptive immune response show anti-inflammatory properties. Unlike other TKIs, Nilotinib determine inflammatory cytokines reduction, preserving T cell population and Treg. These data support the potential use of Nilotinib in cGVHD Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

scholarly journals mRNA induced expression of human angiotensin-converting enzyme 2 in mice for the study of the adaptive immune response to severe acute respiratory syndrome coronavirus 2

2020 ◽  
Author(s):  
Mariah Hassert ◽  
Elizabeth Geerling ◽  
E. Taylor Stone ◽  
Tara L. Steffen ◽  
Madi S. Feldman ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Severe Acute Respiratory Syndrome ◽  
Angiotensin Converting Enzyme ◽  
Expression System ◽  
Adaptive Immune Response ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Adaptive Immune

AbstractThe novel human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic resulting in nearly 20 million infections across the globe, as of August 2020. Critical to the rapid evaluation of vaccines and antivirals is the development of tractable animal models of infection. The use of common laboratory strains of mice to this end is hindered by significant divergence of the angiotensin-converting enzyme 2 (ACE2), which is the receptor required for entry of SARS-CoV-2. In the current study, we designed and utilized an mRNA-based transfection system to induce expression of the hACE2 receptor in order to confer entry of SARS-CoV-2 in otherwise non-permissive cells. By employing this expression system in an in vivo setting, we were able to interrogate the adaptive immune response to SARS-CoV-2 in type 1 interferon receptor deficient mice. In doing so, we showed that the T cell response to SARS-CoV-2 is enhanced when hACE2 is expressed during infection. Moreover, we demonstrated that these responses are preserved in memory and are boosted upon secondary infection. Interestingly, we did not observe an enhancement of SARS-CoV-2 specific antibody responses with hACE2 induction. Importantly, using this system, we functionally identified the CD4+ and CD8+ peptide epitopes targeted during SARS-CoV-2 infection in H2b restricted mice. Antigen-specific CD8+ T cells in mice of this MHC haplotype primarily target peptides of the spike and membrane proteins, while the antigen-specific CD4+ T cells target peptides of the nucleocapsid, membrane, and spike proteins. The functional identification of these T cell epitopes will be critical for evaluation of vaccine efficacy in murine models of SARS-CoV-2. The use of this tractable expression system has the potential to be used in other instances of emerging infections in which the rapid development of an animal model is hindered by a lack of host susceptibility factors.

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