Cytomegalovirus Specific Immunity Protects From Cytomegalovirus Replication After Hematopoietic Stem Cell Transplantation.

Abstract Abstract 1281 Background: Cytomegalovirus (CMV) end-organ disease is a serious complication after allogeneic stem cell transplantation (Allo-SCT). The quality of the post-transplant immune reconstitution plays a crucial role in the development of both, post-transplant infections and relapse of the underlying disease, two of the main factors conditioning post-transplant mortality and hence final survival. The relationship between viral replication and CMV specific immune reconstitution has not been completely unveiled. This knowledge would allow identifying patients at risk for developing CMV disease and eventually improving their clinical management. Objectives: to analyze the relationship between CMV replication and specific CMV immune reconstitution and the potential influence of this relationship in main clinical outcomes. Patients and Methods: A prospective study of consecutive recipients of Allo-SCT was performed from June 2008 through December 2009 at a single institution. Blood samples were collected from one week before transplant, weekly during the first three months after transplant, every other week from month three to six and monthly from month seven to complete one year of follow up. CMV viral load was determined by real time PCR and CMV-specific T cell response was determined by flow cytometry with surface markers and intracellular cytokine staining. The percentage of activated CD4+, CD8+ and CD3+ T cells expressing CD69 were considered positive when IFN-’Y cytokine secretion was over 0.25%. Chimerism of the isolated CD8+ T cell subpopulation was determined by PCR. CD69 expression and cytokine secretion were compared in both CD4+ and CD8+ T cells between the different time points and both subsets of patients by the Wilcoxon test. CMV viral load reduction without treatment administration was compared by Wilcoxon test. Differences were considered statistically significant for p-values < 0.05. All statistical analyses were performed using SPSS 16.0 software (Chicago, IL). Results: Twenty-six patients were enrolled in the study with a median age of 33 years (range:15-61). We identified two groups of patients. A first group of 18 (69.2%) patients developed CMV infection and acquired CMV-specific T cell response by median week 8 (range:1-22; Figure 1A). The decline in the incidence of CMV replication episodes correlated with the acquisition of CMV-specific T cell response (Linear regresion r2=0.781, Pearson correlation p=0.01). A second group of 8 patients (30.8%) never developed CMV infection after the transplant, with a median value of 2 weeks (range:1-7; Figure 1B). The time of the acquisition of CMV-specific T cell response for the group with viremia and for the non-viremic group (week 2 vs. week 8) was statistically different (p= 0.01). Fifteen per cent of the patients (n=4) developed end-organ disease. Three out of five patients with end-organ disease developed replication CMV episodes over 10,000 copies/ml, while only 1 out of 13 patients with no end-organ disease developed viral loads under 10,000 copies/ml (p=0.04). The percentage of positive CD8+ T cells expressing IFN-γ in the patients that developed disease tended to be lower than in the patients that did not develop disease (median percentage of IFN-g positive CD8 T cells 0.3 vs. 0.5, respectively). The chimerism of the CD8+ T cells subpopulation after acquiring the specific immune response was of complete donor origin for all the patients. Conclusions: Developing donor-derived T-cell mediated CMV-specific immune response within the following two weeks after the transplant is inversely associated with the development CMV infection. The level of CMV viral load may predict end-organ disease. The use of a tool to determine T-cell mediated CMV-specific immune response in the clinical practice may help to improve the management of these patients, avoiding unnecessary treatments, and predicting clinical outcomes. Disclosures: No relevant conflicts of interest to declare.

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Initial viral load determines the magnitude of the human CD8 T cell response to yellow fever vaccination

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1500475112 ◽

2015 ◽

Vol 112 (10) ◽

pp. 3050-3055 ◽

Cited By ~ 70

Author(s):

Rama S. Akondy ◽

Philip L. F. Johnson ◽

Helder I. Nakaya ◽

Srilatha Edupuganti ◽

Mark J. Mulligan ◽

...

Keyword(s):

Immune Response ◽

T Cells ◽

Viral Load ◽

T Cell ◽

Yellow Fever ◽

Cd8 T Cells ◽

Cell Response ◽

Cd8 T Cell ◽

T Cell Response ◽

Virus Load

CD8 T cells are a potent tool for eliminating intracellular pathogens and tumor cells. Thus, eliciting robust CD8 T-cell immunity is the basis for many vaccines under development. However, the relationship between antigen load and the magnitude of the CD8 T-cell response is not well-described in a human immune response. Here we address this issue by quantifying viral load and the CD8 T-cell response in a cohort of 80 individuals immunized with the live attenuated yellow fever vaccine (YFV-17D) by sampling peripheral blood at days 0, 1, 2, 3, 5, 7, 9, 11, 14, 30, and 90. When the virus load was below a threshold (peak virus load < 225 genomes per mL, or integrated virus load < 400 genome days per mL), the magnitude of the CD8 T-cell response correlated strongly with the virus load (R2∼ 0.63). As the virus load increased above this threshold, the magnitude of the CD8 T-cell responses saturated. Recent advances in CD8 T-cell–based vaccines have focused on replication-incompetent or single-cycle vectors. However, these approaches deliver relatively limited amounts of antigen after immunization. Our results highlight the requirement that T-cell–based vaccines should deliver sufficient antigen during the initial period of the immune response to elicit a large number of CD8 T cells that may be needed for protection.

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Recovery of CMV-Specific T Cells Following Alternative Donor Allogeneic Transplant with Post-Transplant Cyclophosphamide

Blood ◽

10.1182/blood.v126.23.5462.5462 ◽

2015 ◽

Vol 126 (23) ◽

pp. 5462-5462

Author(s):

Ayman Saad ◽

Samantha B Langford ◽

Shin Mineishi ◽

Lawrence S. Lamb

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cell Response ◽

Cd8 T Cell ◽

T Cell Response ◽

Cell Recovery ◽

Post Transplant ◽

Increased Risk ◽

Cmv Reactivation

Abstract Background: Post-transplant cyclophosphamide (PTCy) is increasingly used for GVHD prophylaxis after allogeneic hematopoietic stem cell transplantation (HCT) using alternative donors. However, immune reconstitution can be delayed posing an increased risk for CMV reactivation. We evaluated the outcomes of patients who received HCT-apheresis products comparing the impact of PTCy on lymphocyte recovery, CMV reactivation and CMV-specific CD8+ T cell recovery following haplo-identical (HAPLO), matched unrelated donor (MUD), and mismatched unrelated donor (mMUD) grafts vs. with conventional matched related donor (MRD) graft recipients. Methods: We examined 26 patients (median age, 49 years; range, 20-72 years) with advanced hematologic malignancies; n=5 (HAPLO); 6 (MRD); 15 (MUD). All patients received myeloablative conditioning regimens that was either busulfan- or total body irradiation (TBI)-based. PTCy (50 mg/kg/day) was administered on days +3 and +4 following HAPLO and on day +3 following MUD/mMUD transplant. Peripheral blood lymphocyte reconstitution and frequency of circulating CMV-directed CD8+ T cells was assessed (day ± 10 days) on post-transplant days +30, +60, and +90. Circulating anti-CMV T cell frequency was assessed using a phycoerythrin-tagged MHC dextramer against HLA-specific CMV pp65, IE-1, or pp50 peptides (Immudex; Copenhagen, DK) in combination with Tru-Count¨ tubes and fluorescent-labeled monoclonal antibodies against CD3, CD8, CD4, CD16/56, and CD19 (BD Biosciences; San Jose, CA). Anti-CMV CD8+ T cell immunity was defined as a CMV-dextramer (CMV/DEX) positive count of ≥7cells/ml. CMV reactivation was defined as a serologic titer of >500IU/mL. All patients with CMV reactivation received ganciclovir therapy until CMV titer became negative. Results: Day +30 total T cell recovery was significantly faster in MRD than CY-treated recipients (p=0.015) due principally to more robust CD8+ T cell recovery. CD4 T cell recovery remained below normal range in all groups through day +100. NK cells recovered to normal numbers at day +28 in all groups. Neither PTCy nor donor source significantly impacted the percentage of patients that recovered anti-CMV CD8+ T cells at each time interval (p = 0.8232). Excluding donors (D) and recipients (R) that were both negative, CMV/DEX+ T cells recovery was >7/mL in 4/5 MRD, 7/14 MUD, and 3/5 HAPLO by day +100. Among MRD recipients either D+ or R+ (n=5), 2 patients showed CMV reactivation within 40 days of transplant that was associated with <7 CMV/DEX+ T cells on day +30. Subsequent high (>90/mL) CMV/DEX T cell response in one patient shortened the duration of viremia to 10 days (vs. 16 days with poor responder) and 3 patients showed no CMV reactivation and a high CMV/DEX+ T cell response by day +60. For MUD CMV D+ and/or R+ recipients (n=14), 3 showed CMV reactivation within 50 days of transplant. All 3 patients had suboptimal CMV/DEX T cell response on day +30. Robust CMV/DEX+ T cell response on day +60 predicted shorter duration of viremia (20 days vs. average of 32 days). For HAPLO CMV D+ and/or R+ (n=5) recipients, 4 experienced CMV reactivation within 50 days of transplant. All patients had a <7 CMV/DEX+ T cells/mL +30. Robust CMV/DEX+ T cell response by day +60 was associated with shorter duration of viremia (range 7-21 days), while one patient with <7/mL CMV/DEX+ T cells had continued CMV viremia for 36 days. Conclusion: In this preliminary analysis, neither PTCy nor donor source significantly impacted the percentage of patients that recovered anti-CMV CD8+ T cells at each time interval. A weak CMV/DEX+ response (<7 cells/mL) on day +30 was consistent with increased risk of CMV reactivation (viremia) in all groups. A CMV/DEX+ T cell count ≥7 cells/mL was not immediately protective against CMV reactivation, but higher counts were associated with a shortened duration of viremia while on antiviral therapy. Conversely, subnormal counts were associated with a longer duration of viremia. This interim analysis suggests that CMV/DEX+ T cell enumeration is a useful biologic correlate for determining clinical response to antiviral therapy, and that donor-derived CMV specific T cell immunity is not further compromised with following PTCy in alternative donor HCT. Disclosures No relevant conflicts of interest to declare.

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Direct Visualization of Antigen-specific CD8+T Cells during the Primary Immune Response to Epstein-Barr Virus In Vivo

Journal of Experimental Medicine ◽

10.1084/jem.187.9.1395 ◽

1998 ◽

Vol 187 (9) ◽

pp. 1395-1402 ◽

Cited By ~ 631

Author(s):

M.F.C. Callan ◽

L. Tan ◽

N. Annels ◽

G.S. Ogg ◽

J.D.K. Wilson ◽

...

Keyword(s):

Immune Response ◽

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cell Response ◽

Epstein Barr Virus ◽

T Cell Response ◽

Primary Immune Response ◽

Barr Virus ◽

Epstein Barr

Primary infection with virus can stimulate a vigorous cytotoxic T cell response. The magnitude of the antigen-specific component versus the bystander component of a primary T cell response remains controversial. In this study, we have used tetrameric major histocompatibility complex–peptide complexes to directly visualize antigen-specific cluster of differentration (CD)8+ T cells during the primary immune response to Epstein-Barr virus (EBV) infection in humans. We show that massive expansion of activated, antigen-specific T cells occurs during the primary response to this virus. In one individual, T cells specific for a single EBV epitope comprised 44% of the total CD8+ T cells within peripheral blood. The majority of the antigen-specific cells had an activated/memory phenotype, with expression of human histocompatibility leukocyte antigen (HLA) DR, CD38, and CD45RO, downregulation of CD62 leukocyte (CD62L), and low levels of expression of CD45RA. After recovery from AIM, the frequency of antigen-specific T cells fell in most donors studied, although populations of antigen-specific cells continued to be easily detectable for at least 3 yr.

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A gammaherpesvirus-secreted activator of Vβ4+ CD8+ T cells regulates chronic infection and immunopathology

Journal of Experimental Medicine ◽

10.1084/jem.20071135 ◽

2008 ◽

Vol 205 (3) ◽

pp. 669-684 ◽

Cited By ~ 46

Author(s):

Andrew G. Evans ◽

Janice M. Moser ◽

Laurie T. Krug ◽

Veranika Pozharskaya ◽

Ana L. Mora ◽

...

Keyword(s):

Immune Response ◽

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Response ◽

Cell Activation ◽

Cd8 T Cell ◽

T Cell Response ◽

Murine Gammaherpesvirus

Little is known about herpesvirus modulation of T cell activation in latently infected individuals or the implications of such for chronic immune disorders. Murine gammaherpesvirus 68 (MHV68) elicits persistent activation of CD8+ T cells bearing a Vβ4+ T cell receptor (TCR) by a completely unknown mechanism. We show that a novel MHV68 protein encoded by the M1 gene is responsible for Vβ4+ CD8+ T cell stimulation in a manner reminiscent of a viral superantigen. During infection, M1 expression induces a Vβ4+ effector T cell response that resists functional exhaustion and appears to suppress virus reactivation from peritoneal cells by means of long-term interferon-γ (IFNγ) production. Mice lacking an IFNγ receptor (IFNγR−/−) fail to control MHV68 replication, and Vβ4+ and CD8+ T cell activation by M1 instead contributes to severe inflammation and multiorgan fibrotic disease. Thus, M1 manipulates the host CD8+ T cell response in a manner that facilitates latent infection in an immunocompetent setting, but promotes disease during a dysregulated immune response. Identification of a viral pathogenecity determinant with superantigen-like activity for CD8+ T cells broadens the known repertoire of viral immunomodulatory molecules, and its function illustrates the delicate balance achieved between persistent viruses and the host immune response.

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Type I Interferons Regulate the Magnitude and Functionality of Mouse Polyomavirus-Specific CD8 T Cells in a Virus Strain-Dependent Manner

Journal of Virology ◽

10.1128/jvi.00199-16 ◽

2016 ◽

Vol 90 (10) ◽

pp. 5187-5199 ◽

Cited By ~ 7

Author(s):

Qingsong Qin ◽

Shwetank ◽

Elizabeth L. Frost ◽

Saumya Maru ◽

Aron E. Lukacher

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cell Response ◽

Cd8 T Cell ◽

T Cell Response ◽

Single Amino Acid ◽

Type I ◽

Type I Ifns ◽

Vp1 Capsid Protein

ABSTRACTMouse polyomavirus (MPyV) is a ubiquitous persistent natural mouse pathogen. A glutamic acid (E)-to-glycine (G) difference at position 91 of the VP1 capsid protein shifts the profile of tumors induced by MPyV from an epithelial to a mesenchymal cell origin. Here we asked if this tropism difference affects the MPyV-specific CD8 T cell response, which controls MPyV infection and tumorigenesis. Infection by the laboratory MPyV strain RA (VP1-91G) or a strain A2 mutant with an E-to-G substitution at VP1 residue 91 [A2(91G)] generated a markedly smaller virus-specific CD8 T cell response than that induced by A2(VP1-91E) infection. Mutant A2(91G)-infected mice showed a higher frequency of memory precursor (CD127hiKLRG1lo) CD8 T cells and a higher recall response than those of A2-infected mice. Using T cell receptor (TCR)-transgenic CD8 T cells and immunization with peptide-pulsed dendritic cells, we found that early bystander inflammation associated with A2 infection contributed to recruitment of the larger MPyV-specific CD8 T cell response. Beta interferon (IFN-β) transcripts were induced early during A2 or A2(91G) infections. IFN-β inhibited replication of A2 and A2(91G)in vitro. Using mice lacking IFN-αβ receptors (IFNAR−/−), we showed that type I IFNs played a role in controlling MPyV replicationin vivobut differentially affected the magnitude and functionality of virus-specific CD8 T cells recruited by A2 and A2(91G) viral infections. These data indicate that type I IFNs are involved in protection against MPyV infection and that their effect on the antiviral CD8 T cell response depends on capsid-mediated tropism properties of the MPyV strain.IMPORTANCEIsolates of the human polyomavirus JC virus from patients with the frequently fatal demyelinating brain disease progressive multifocal leukoencephalopathy (PML) carry single amino acid substitutions in the domain of the VP1 capsid protein that binds the sialic acid moiety of glycoprotein/glycolipid receptors on host cells. These VP1 mutations may alter neural cell tropism or enable escape from neutralizing antibodies. Changes in host cell tropism can affect recruitment of virus-specific CD8 T cells. Using mouse polyomavirus, we demonstrate that a single amino acid difference in VP1 known to shift viral tropism profoundly affects the quantity and quality of the anti-polyomavirus CD8 T cell response and its differentiation into memory cells. These findings raise the possibility that CD8 T cell responses to infections by human polyomaviruses may be influenced by VP1 mutations involving domains that engage host cell receptors.

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Role of Thymic Output in Regulating CD8 T-Cell Homeostasis during Acute and Chronic Viral Infection

Journal of Virology ◽

10.1128/jvi.79.15.9419-9429.2005 ◽

2005 ◽

Vol 79 (15) ◽

pp. 9419-9429 ◽

Cited By ~ 29

Author(s):

Nicole E. Miller ◽

Jennifer R. Bonczyk ◽

Yumi Nakayama ◽

M. Suresh

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cell Response ◽

Viral Infections ◽

T Cell Responses ◽

Cd8 T Cell ◽

T Cell Response ◽

Cell Responses ◽

Lcmv Infection

ABSTRACT Although it is well documented that CD8 T cells play a critical role in controlling chronic viral infections, the mechanisms underlying the regulation of CD8 T-cell responses are not well understood. Using the mouse model of an acute and chronic lymphocytic choriomeningitis virus (LCMV) infection, we have examined the relative importance of peripheral T cells and thymic emigrants in the elicitation and maintenance of CD8 T-cell responses. Virus-specific CD8 T-cell responses were compared between mice that were either sham thymectomized or thymectomized (Thx) at ∼6 weeks of age. In an acute LCMV infection, thymic deficiency did not affect either the primary expansion of CD8 T cells or the proliferative renewal and maintenance of virus-specific lymphoid and nonlymphoid memory CD8 T cells. Following a chronic LCMV infection, in Thx mice, although the initial expansion of CD8 T cells was normal, the contraction phase of the CD8 T-cell response was exaggerated, which led to a transient but striking CD8 T-cell deficit on day 30 postinfection. However, the virus-specific CD8 T-cell response in Thx mice rebounded quickly and was maintained at normal levels thereafter, which indicated that the peripheral T-cell repertoire is quite robust and capable of sustaining an effective CD8 T-cell response in the absence of thymic output during a chronic LCMV infection. Taken together, these findings should further our understanding of the regulation of CD8 T-cell homeostasis in acute and chronic viral infections and might have implications in the development of immunotherapy.

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Contribution of Herpesvirus Specific CD8 T Cells to Anti-Viral T Cell Response in Humans

PLoS Pathogens ◽

10.1371/journal.ppat.1001051 ◽

2010 ◽

Vol 6 (8) ◽

pp. e1001051 ◽

Cited By ~ 42

Author(s):

Elena Sandalova ◽

Diletta Laccabue ◽

Carolina Boni ◽

Anthony T. Tan ◽

Katja Fink ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cell Response ◽

T Cell Response

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CD4+CD8+T Cells Represent a Significant Portion of the Anti-HIV T Cell Response to Acute HIV Infection

The Journal of Immunology ◽

10.4049/jimmunol.1103701 ◽

2012 ◽

Vol 188 (9) ◽

pp. 4289-4296 ◽

Cited By ~ 32

Author(s):

Marc A. Frahm ◽

Ralph A. Picking ◽

JoAnn D. Kuruc ◽

Kara S. McGee ◽

Cynthia L. Gay ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Hiv Infection ◽

Cd8 T Cells ◽

Cell Response ◽

T Cell Response ◽

Acute Hiv Infection ◽

Acute Hiv ◽

Anti Hiv

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Mucosal CD8+ T cell responses induced by an MCMV based vaccine vector confer protection against influenza challenge

10.1101/494864 ◽

2018 ◽

Author(s):

Xiaoyan Zheng ◽

Jennifer Dora Oduro ◽

Julia Désirée Boehme ◽

Lisa Borkner ◽

Thomas Ebensen ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cell Response ◽

Influenza A ◽

Clinical Medicine ◽

Cd8 T Cell ◽

T Cell Response ◽

Vaccine Vector ◽

Protective Capacity

Cytomegalovirus (CMV) is a ubiquitous β-herpesvirus that establishes life-long latent infection in a high percentage of the population worldwide. CMV induces the strongest and most durable CD8+ T cell response known in human clinical medicine. Due to its unique properties, the virus represents a promising candidate vaccine vector for the induction of persistent cellular immunity. To take advantage of this, we constructed a recombinant murine CMV (MCMV) expressing an MHC-I restricted epitope from influenza A virus (IAV) H1N1 within the immediate early 2 (ie2) gene. Only mice that were immunized intranasally (i.n.) were capable of controlling IAV infection, despite the greater potency of the intraperitoneally (i.p.) vaccination in inducing a systemic IAV-specific CD8+ T cell response. The protective capacity of the i.n. immunization was associated with its ability to induce IAV-specific tissue-resident memory CD8+ T (CD8TRM) cells in the lungs. Our data demonstrate that the protective effect exerted by the i.n. immunization was critically mediated by antigen-specific CD8+ T cells. CD8TRM cells promoted the induction of IFNγ and chemokines that facilitate the recruitment of antigen-specific CD8+ T cells to the lungs. Overall, our results showed that locally applied MCMV vectors could induce mucosal immunity at sites of entry, providing superior immune protection against respiratory infections.

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Neoantigen-specific CD4+ T-cell response is critical for the therapeutic efficacy of cryo-thermal therapy

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2019-000421 ◽

2020 ◽

Vol 8 (2) ◽

pp. e000421

Author(s):

Peng Peng ◽

Hongming Hu ◽

Ping Liu ◽

Lisa X Xu

Keyword(s):

Immune Response ◽

T Cells ◽

T Cell ◽

Tumor Antigen ◽

Cell Response ◽

Antitumor Immunity ◽

T Cell Response ◽

Thermal Therapy ◽

Term Survival

BackgroundTraditional tumor thermal ablations, such as radiofrequency ablation (RFA) and cryoablation, can result in good local control of tumor, but traditional tumor thermal ablations are limited by poor long-term survival due to the failure of control of distal metastasis. Our previous studies developed a novel cryo-thermal therapy to treat the B16F10 melanoma mouse model. Long-term survival and T-cell-mediated durable antitumor immunity were achieved after cryo-thermal therapy, but whether tumor antigen-specific T-cells were augmented by cryo-thermal therapy was not determined.MethodsThe long-term antitumor therapeutic efficacy of cryo-thermal therapy was performed in B16F10 murine melanoma models. Splenocytes derived from mice treated with RFA or cryo-thermal therapy were coincubated with tumor antigen peptides to detect the frequency of antigen specific CD4+ and CD8+ T-cells by flow cytometry. Splenocytes were then stimulated and expanded by αCD3 or peptides and adoptive T-cell therapy experiments were performed to identify the antitumor efficacy of T-cells induced by RFA and cryo-thermal therapy. Naïve mice and tumor-bearing mice were used as control groups.ResultsLocal cryo-thermal therapy generated a stronger systematic antitumor immune response than RFA and a long-lasting antitumor immunity that protected against tumor rechallenge. In vitro studies showed that the antigen-specific CD8+ T-cell response was induced by both cryo-thermal therapy and RFA, but the strong neoantigen-specific CD4+ T-cell response was only induced by cryo-thermal therapy. Cryo-thermal therapy-induced strong antitumor immune response was mainly mediated by CD4+ T-cells, particularly neoantigen-specific CD4+ T-cells.ConclusionCryo-thermal therapy induced a stronger and broader antigen-specific memory T-cells. Specifically, cryo-thermal therapy, but not RFA, led to a strong neoantigen-specific CD4+ T-cell response that mediated the resistance to tumor challenge.

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