scholarly journals Single dose of anti–CTLA-4 enhances CD8+T-cell memory formation, function, and maintenance

2010 ◽  
Vol 108 (1) ◽  
pp. 266-271 ◽  
Author(s):  
Virginia A. Pedicord ◽  
Welby Montalvo ◽  
Ingrid M. Leiner ◽  
James P. Allison
Keyword(s):  
T Cell ◽  
T Cell Responses ◽  
Memory Cell ◽  
Memory Formation ◽  
T Cell Memory ◽  
Cell Repertoire ◽  
Cell Memory ◽  
Cell Responses ◽  
Blocking Antibodies

CTLA-4, an Ig superfamily molecule with homology to CD28, is one of the most potent negative regulators of T-cell responses. In vivo blockade of CTLA-4 exacerbates autoimmunity, enhances tumor-specific T-cell responses, and may inhibit the induction of T-cell anergy. Clinical trials of CTLA-4–blocking antibodies to augment T-cell responses to malignant melanoma are at an advanced stage; however, little is known about the effects of CTLA-4 blockade on memory CD8+T-cell responses and the formation and maintenance of long-term CD8+T-cell memory. In our studies, we show that during in vivo memory CD8+T-cell responses toListeria monocytogenesinfection, CTLA-4 blockade enhances bacterial clearance and increases memory CD8+T-cell expansion. This is followed by an accumulation of memory cells that are capable of producing the effector cytokines IFN-γ and TNF-α. We also demonstrate that in a vaccination setting, blocking CTLA-4 during CD8+T-cell priming leads to increased expansion and maintenance of antigen-specific memory CD8+T cells without adversely affecting the overall T-cell repertoire. This leads to an increase in memory cell effector function and improved protective immunity against further bacterial challenges. These results indicate that transient blockade of CTLA-4 enhances memory CD8+T-cell responses and support the possible use of CTLA-4–blocking antibodies during vaccination to augment memory formation and maintenance.

scholarly journals Convergent epitope-specific T cell responses after SARS-CoV-2 infection and vaccination

2021 ◽  
Author(s):  
Anastasia A Minervina ◽  
Mikhail V Pogorelyy ◽  
Allison M Kirk ◽  
Emma Kaitlynn Allen ◽  
Kim J Allison ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mononuclear Cells ◽  
T Cell Responses ◽  
T Cell Response ◽  
Critical Parameters ◽  
T Cell Memory ◽  
Cell Memory ◽  
Cell Responses ◽  
Depth Analysis

SARS-CoV-2 mRNA vaccines, including Pfizer/Biontech BNT162b2, were shown to be effective for COVID-19 prevention, eliciting both robust antibody responses in naive individuals and boosting pre-existing antibody levels in SARS-CoV-2-recovered individuals. However, the magnitude, repertoire, and phenotype of epitope-specific T cell responses to this vaccine, and the effect of vaccination on pre-existing T cell memory in SARS-CoV-2 convalescent patients, are still poorly understood. Thus, in this study we compared epitope-specific T cells elicited after natural SARS-CoV-2 infection, and vaccination of both naive and recovered individuals. We collected peripheral blood mononuclear cells before and after BNT162b2 vaccination and used pools of 18 DNA-barcoded MHC-class I multimers, combined with scRNAseq and scTCRseq, to characterize T cell responses to several immunodominant epitopes, including a spike-derived epitope cross-reactive to common cold coronaviruses. Comparing responses after infection or vaccination, we found that T cells responding to spike-derived epitopes show similar magnitudes of response, memory phenotypes, TCR repertoire diversity, and αβTCR sequence motifs, demonstrating the potency of this vaccination platform. Importantly, in COVID-19-recovered individuals receiving the vaccine, pre-existing spike-specific memory cells showed both clonal expansion and a phenotypic shift towards more differentiated CCR7-CD45RA+ effector cells. In-depth analysis of T cell receptor repertoires demonstrates that both vaccination and infection elicit largely identical repertoires as measured by dominant TCR motifs and receptor breadth, indicating that BNT162b2 vaccination largely recapitulates T cell generation by infection for all critical parameters. Thus, BNT162b2 vaccination elicits potent spike-specific T cell responses in naive individuals and also triggers the recall T cell response in previously infected individuals, further boosting spike-specific responses but altering their differentiation state. Overall, our study demonstrates the potential of mRNA vaccines to induce, maintain, and shape T cell memory through vaccination and revaccination.

scholarly journals Loss of Preexisting Immunological Memory Among Human Immunodeficiency Virus–Infected Women Despite Immune Reconstitution With Antiretroviral Therapy

2019 ◽  
Vol 222 (2) ◽  
pp. 243-251 ◽  
Author(s):  
Archana Thomas ◽  
Erika Hammarlund ◽  
Lina Gao ◽  
Susan Holman ◽  
Katherine G Michel ◽  
...  
Keyword(s):  
T Cell ◽  
Antiretroviral Therapy ◽  
Immune Reconstitution ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cd4 T Cell ◽  
T Cell Memory ◽  
Cell Memory ◽  
Cell Responses ◽  
Immunodeficiency Virus

Abstract Background It is unclear whether human immunodeficiency virus (HIV) infection results in permanent loss of T-cell memory or if it affects preexisting antibodies to childhood vaccinations or infections. Methods We conducted a matched cohort study involving 50 pairs of HIV-infected and HIV-uninfected women. Total memory T-cell responses were measured after anti-CD3 or vaccinia virus (VV) stimulation to measure T cells elicited after childhood smallpox vaccination. VV-specific antibodies were measured by means of enzyme-linked immunosorbent assay (ELISA). Results There was no difference between HIV-infected and HIV-uninfected study participants in terms of CD4+ T-cell responses after anti-CD3 stimulation (P = .19) although HIV-infected participants had significantly higher CD8+ T-cell responses (P = .03). In contrast, there was a significant loss in VV-specific CD4+ T-cell memory among HIV-infected participants (P = .04) whereas antiviral CD8+ T-cell memory remained intact (P > .99). VV-specific antibodies were maintained indefinitely among HIV-uninfected participants (half-life, infinity; 95% confidence interval, 309 years to infinity) but declined rapidly among HIV-infected participants (half-life; 39 years; 24–108 years; P = .001). Conclusions Despite antiretroviral therapy–associated improvement in CD4+ T-cell counts (nadir, <200/μL; >350/μL after antiretroviral therapy), antigen-specific CD4+ T-cell memory to vaccinations or infections that occurred before HIV infection did not recover after immune reconstitution, and a previously unrealized decline in preexisting antibody responses was observed.

scholarly journals Increased Immune Response Variability during Simultaneous Viral Coinfection Leads to Unpredictability in CD8 T Cell Immunity and Pathogenesis

2015 ◽  
Vol 89 (21) ◽  
pp. 10786-10801 ◽  
Author(s):  
Laurie L. Kenney ◽  
Markus Cornberg ◽  
Alex T. Chen ◽  
Sebastien Emonet ◽  
Juan Carlos de la Torre ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
T Cell Memory ◽  
T Cell Epitopes ◽  
Cell Memory ◽  
Cell Responses ◽  
Cell Immunity ◽  
Cd8 T Cell Memory

ABSTRACTT cell memory is usually studied in the context of infection with a single pathogen in naive mice, but how memory develops during a coinfection with two pathogens, as frequently occurs in nature or after vaccination, is far less studied. Here, we questioned how the competition between immune responses to two viruses in the same naive host would influence the development of CD8 T cell memory and subsequent disease outcome upon challenge. Using two different models of coinfection, including the well-studied lymphocytic choriomeningitis (LCMV) and Pichinde (PICV) viruses, several differences were observed within the CD8 T cell responses to either virus. Compared to single-virus infection, coinfection resulted in substantial variation among mice in the size of epitope-specific T cell responses to each virus. Some mice had an overall reduced number of virus-specific cells to either one of the viruses, and other mice developed an immunodominant response to a normally subdominant, cross-reactive epitope (nucleoprotein residues 205 to 212, or NP205). These changes led to decreased protective immunity and enhanced pathology in some mice upon challenge with either of the original coinfecting viruses. In mice with PICV-dominant responses, during a high-dose challenge with LCMV clone 13, increased immunopathology was associated with a reduced number of LCMV-specific effector memory CD8 T cells. In mice with dominant cross-reactive memory responses, during challenge with PICV increased immunopathology was directly associated with these cross-reactive NP205-specific CD8 memory cells. In conclusion, the inherent competition between two simultaneous immune responses results in significant alterations in T cell immunity and subsequent disease outcome upon reexposure.IMPORTANCECombination vaccines and simultaneous administration of vaccines are necessary to accommodate required immunizations and maintain vaccination rates. Antibody responses generally correlate with protection and vaccine efficacy. However, live attenuated vaccines also induce strong CD8 T cell responses, and the impact of these cells on subsequent immunity, whether beneficial or detrimental, has seldom been studied, in part due to the lack of known T cell epitopes to vaccine viruses. We questioned if the inherent increased competition and stochasticity between two immune responses during a simultaneous coinfection would significantly alter CD8 T cell memory in a mouse model where CD8 T cell epitopes are clearly defined. We show that some of the coinfected mice have sufficiently altered memory T cell responses that they have decreased protection and enhanced immunopathology when reexposed to one of the two viruses. These data suggest that a better understanding of human T cell responses to vaccines is needed to optimize immunization strategies.

scholarly journals Neutrophil subtypes shape HIV-specific CD8 T-cell responses after vaccinia virus infection

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Mauro Di Pilato ◽  
Miguel Palomino-Segura ◽  
Ernesto Mejías-Pérez ◽  
Carmen E. Gómez ◽  
Andrea Rubio-Ponce ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Vaccinia Virus ◽  
Adaptive Immune System ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cell Responses ◽  
Adaptive Immune

AbstractNeutrophils are innate immune cells involved in the elimination of pathogens and can also induce adaptive immune responses. Nα and Nβ neutrophils have been described with distinct in vitro capacity to generate antigen-specific CD8 T-cell responses. However, how these cell types exert their role in vivo and how manipulation of Nβ/Nα ratio influences vaccine-mediated immune responses are not known. In this study, we find that these neutrophil subtypes show distinct migratory and motility patterns and different ability to interact with CD8 T cells in the spleen following vaccinia virus (VACV) infection. Moreover, after analysis of adhesion, inflammatory, and migration markers, we observe that Nβ neutrophils overexpress the α4β1 integrin compared to Nα. Finally, by inhibiting α4β1 integrin, we increase the Nβ/Nα ratio and enhance CD8 T-cell responses to HIV VACV-delivered antigens. These findings provide significant advancements in the comprehension of neutrophil-based control of adaptive immune system and their relevance in vaccine design.

scholarly journals Optimized Adenovirus-Antibody Complexes Stimulate Strong Cellular and Humoral Immune Responses against an Encoded Antigen in Naïve Mice and Those with Preexisting Immunity

2011 ◽  
Vol 19 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Jin Huk Choi ◽  
Joe Dekker ◽  
Stephen C. Schafer ◽  
Jobby John ◽  
Craig E. Whitfill ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
T Cell Responses ◽  
Transduction Efficiency ◽  
Virus Antibody ◽  
Cell Responses

ABSTRACTThe immune response to recombinant adenoviruses is the most significant impediment to their clinical use for immunization. We test the hypothesis that specific virus-antibody combinations dictate the type of immune response generated against the adenovirus and its transgene cassette under certain physiological conditions while minimizing vector-induced toxicity.In vitroandin vivoassays were used to characterize the transduction efficiency, the T and B cell responses to the encoded transgene, and the toxicity of 1 × 1011adenovirus particles mixed with different concentrations of neutralizing antibodies. Complexes formed at concentrations of 500 to 0.05 times the 50% neutralizing dose (ND50) elicited strong virus- and transgene-specific T cell responses. The 0.05-ND50formulation elicited measurable anti-transgene antibodies that were similar to those of virus alone (P= 0.07). This preparation also elicited very strong transgene-specific memory T cell responses (28.6 ± 5.2% proliferation versus 7.7 ± 1.4% for virus alone). Preexisting immunity significantly reduced all responses elicited by these formulations. Although lower concentrations (0.005 and 0.0005 ND50) of antibody did not improve cellular and humoral responses in naïve animals, they did promote strong cellular (0.005 ND50) and humoral (0.0005 ND50) responses in mice with preexisting immunity. Some virus-antibody complexes may improve the potency of adenovirus-based vaccines in naïve individuals, while others can sway the immune response in those with preexisting immunity. Additional studies with these and other virus-antibody ratios may be useful to predict and model the type of immune responses generated against a transgene in those with different levels of exposure to adenovirus.

scholarly journals Imatinib Mesylate Inhibits Antigen-Specific Memory CD8 T Cell Responses In Vivo

2007 ◽  
Vol 178 (4) ◽  
pp. 2028-2037 ◽  
Author(s):  
Parisa Sinai ◽  
Rance E. Berg ◽  
J. Marshall Haynie ◽  
Merrill J. Egorin ◽  
Robert L. Ilaria ◽  
...  
Keyword(s):  
T Cell ◽  
Imatinib Mesylate ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cell Responses ◽  
Specific Memory ◽  
Memory Cd8 T Cell

scholarly journals TRANCE, a Tumor Necrosis Factor Family Member Critical for CD40 Ligand–independent T Helper Cell Activation

1999 ◽  
Vol 189 (7) ◽  
pp. 1025-1031 ◽  
Author(s):  
Martin F. Bachmann ◽  
Brian R. Wong ◽  
Régis Josien ◽  
Ralph M. Steinman ◽  
Annette Oxenius ◽  
...  
Keyword(s):  
T Cell ◽  
Family Member ◽  
T Cell Responses ◽  
Cd40 Ligand ◽  
Cd4 T Cell ◽  
Cell Responses ◽  
T Cell Priming ◽  
Deficient Mice ◽  
Necrosis Factor

CD40 ligand (CD40L), a tumor necrosis factor (TNF) family member, plays a critical role in antigen-specific T cell responses in vivo. CD40L expressed on activated CD4+ T cells stimulates antigen-presenting cells such as dendritic cells, resulting in the upregulation of costimulatory molecules and the production of various inflammatory cytokines required for CD4+ T cell priming in vivo. However, CD40L- or CD40-deficient mice challenged with viruses mount protective CD4+ T cell responses that produce normal levels of interferon γ, suggesting a CD40L/CD40-independent mechanism of CD4+ T cell priming that to date has not been elucidated. Here we show that CD4+ T cell responses to viral infection were greatly diminished in CD40-deficient mice by administration of a soluble form of TNF-related activation-induced cytokine receptor (TRANCE-R) to inhibit the function of another TNF family member, TRANCE. Thus, the TRANCE/TRANCE-R interaction provides costimulation required for efficient CD4+ T cell priming during viral infection in the absence of CD40L/CD40. These results also indicate that not even the potent inflammatory microenvironment induced by viral infections is sufficient to elicit efficient CD4+ T cell priming without proper costimulation provided by the TNF family (CD40L or TRANCE). Moreover, the data suggest that TRANCE/TRANCE-R may be a novel and important target for immune intervention.

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