scholarly journals Complementary Presence of HBV Humoral and T-cell Response Provides Protective Immunity after Neonatal Immunization

2022 ◽  
Vol 000 (000) ◽  
pp. 000-000
Author(s):  
Yunmei Huang ◽  
Yuting Yang ◽  
Tingting Wu ◽  
Zhiyu Li ◽  
Hongmei Xu ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Response ◽  
Protective Immunity ◽  
T Cell Response

scholarly journals Listeria Monocytogenes: A Model Pathogen Continues to Refine Our Knowledge of the CD8 T Cell Response

Pathogens ◽  
2018 ◽  
Vol 7 (2) ◽  
pp. 55 ◽  
Author(s):  
Zhijuan Qiu ◽  
Camille Khairallah ◽  
Brian Sheridan
Keyword(s):  
Listeria Monocytogenes ◽  
T Cell ◽  
Cell Response ◽  
Protective Immunity ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Oral Infection ◽  
T Cell Response ◽  
Infection Model ◽  
Cell Responses

Listeria monocytogenes (Lm) infection induces robust CD8 T cell responses, which play a critical role in resolving Lm during primary infection and provide protective immunity to re-infections. Comprehensive studies have been conducted to delineate the CD8 T cell response after Lm infection. In this review, the generation of the CD8 T cell response to Lm infection will be discussed. The role of dendritic cell subsets in acquiring and presenting Lm antigens to CD8 T cells and the events that occur during T cell priming and activation will be addressed. CD8 T cell expansion, differentiation and contraction as well as the signals that regulate these processes during Lm infection will be explored. Finally, the formation of memory CD8 T cell subsets in the circulation and in the intestine will be analyzed. Recently, the study of CD8 T cell responses to Lm infection has begun to shift focus from the intravenous infection model to a natural oral infection model as the humanized mouse and murinized Lm have become readily available. Recent findings in the generation of CD8 T cell responses to oral infection using murinized Lm will be explored throughout the review. Finally, CD8 T cell-mediated protective immunity against Lm infection and the use of Lm as a vaccine vector for cancer immunotherapy will be highlighted. Overall, this review will provide detailed knowledge on the biology of CD8 T cell responses after Lm infection that may shed light on improving rational vaccine design.

scholarly journals T-cell receptor sequencing identifies prior SARS-CoV-2 infection and correlates with neutralizing antibody titers and disease severity

2021 ◽  
Author(s):  
Rebecca Elyanow ◽  
Thomas M. Snyder ◽  
Sudeb C. Dalai ◽  
Rachel M. Gittelman ◽  
Jim Boonyaratanakornkit ◽  
...  
Keyword(s):  
T Cell ◽  
Disease Severity ◽  
T Cell Receptor ◽  
Cell Response ◽  
Protective Immunity ◽  
Limit Of Detection ◽  
Neutralizing Antibody ◽  
Cell Receptor ◽  
T Cell Response ◽  
Cell Testing

Measuring the adaptive immune response to SARS-CoV-2 can enable the assessment of past infection as well as protective immunity and the risk of reinfection. While neutralizing antibody (nAb) titers are one measure of protection, such assays are challenging to perform at a large scale and the longevity of the SARS-CoV-2 nAb response is not fully understood. Here, we apply a T-cell receptor (TCR) sequencing assay that can be performed on a small volume standard blood sample to assess the adaptive T-cell response to SARS-CoV-2 infection. Samples were collected from a cohort of 302 individuals recovered from COVID-19 up to 6 months after infection. Previously published findings in this cohort showed that two commercially available SARS-CoV-2 serologic assays correlate well with nAb testing. We demonstrate that the magnitude of the SARS-CoV-2-specific T-cell response strongly correlates with nAb titer, as well as clinical indicators of disease severity including hospitalization, fever, or difficulty breathing. While the depth and breadth of the T-cell response declines during convalescence, the T-cell signal remains well above background with high sensitivity up to at least 6 months following initial infection. Compared to serology tests detecting binding antibodies to SARS-CoV-2 spike and nucleoprotein, the overall sensitivity of the TCR-based assay across the entire cohort and all timepoints was approximately 5% greater for identifying prior SARS-CoV-2 infection. Notably, the improved performance of T-cell testing compared to serology was most apparent in recovered individuals who were not hospitalized and were sampled beyond 150 days of their initial illness, suggesting that antibody testing may have reduced sensitivity in individuals who experienced less severe COVID-19 illness and at later timepoints. Finally, T-cell testing was able to identify SARS-CoV-2 infection in 68% (55/81) of convalescent samples having nAb titers below the lower limit of detection, as well as 37% (13/35) of samples testing negative by all three antibody assays. These results demonstrate the utility of a TCR-based assay as a scalable, reliable measure of past SARS-CoV-2 infection across a spectrum of disease severity. Additionally, the TCR repertoire may be useful as a surrogate for protective immunity with additive clinical value beyond serologic or nAb testing methods.

scholarly journals Anti-tumor T cell response and protective immunity in mice that received sublethal irradiation and immune reconstitution

2003 ◽  
Vol 33 (8) ◽  
pp. 2123-2132 ◽  
Author(s):  
Jun Ma ◽  
Walter J. Urba ◽  
Lüsheng Si ◽  
Yili Wang ◽  
Bernard A. Fox ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Response ◽  
Protective Immunity ◽  
Immune Reconstitution ◽  
T Cell Response ◽  
Sublethal Irradiation

scholarly journals Direct Ex Vivo Kinetic and Phenotypic Analyses of CD8+ T-Cell Responses Induced by DNA Immunization

2000 ◽  
Vol 74 (18) ◽  
pp. 8286-8291 ◽  
Author(s):  
Daniel E. Hassett ◽  
Mark K. Slifka ◽  
Jie Zhang ◽  
J. Lindsay Whitton
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Response ◽  
Protective Immunity ◽  
Ex Vivo ◽  
Dna Vaccination ◽  
T Cell Response ◽  
Dna Immunization ◽  
Live Virus ◽  
Cell Responses

ABSTRACT CD8+ T-cell responses can be induced by DNA immunization, but little is known about the kinetics of these responses in vivo in the absence of restimulation or how soon protective immunity is conferred by a DNA vaccine. It is also unclear if CD8+ T cells primed by DNA vaccines express the vigorous effector functions characteristic of cells primed by natural infection or by immunization with a recombinant live virus vaccine. To address these issues, we have used the sensitive technique of intracellular cytokine staining to carry out direct ex vivo kinetic and phenotypic analyses of antigen-specific CD8+ T cells present in the spleens of mice at various times after (i) a single intramuscular administration of a plasmid expressing the nucleoprotein (NP) gene from lymphocytic choriomeningitis virus (LCMV), (ii) infection by a recombinant vaccinia virus carrying the same protein (vvNP), or (iii) LCMV infection. In addition, we have evaluated the rapidity with which protective immunity against both lethal and sublethal LCMV infections is achieved following DNA vaccination. The CD8+ T-cell response in DNA-vaccinated mice was slightly delayed compared to LCMV or vvNP vaccinees, peaking at 15 days postimmunization. Interestingly, the percentage of antigen-specific CD8+ T cells present in the spleen at day 15 and later time points was similar to that observed following vvNP infection. T cells primed by DNA vaccination or by infection exhibited similar cytokine expression profiles and had similar avidities for an immunodominant cytotoxic T lymphocyte epitope peptide, implying that the responses induced by DNA vaccination differ quantitatively but not qualitatively from those induced by live virus infection. Surprisingly, protection from both lethal and sublethal LCMV infections was conferred within 1 week of DNA vaccination, well before the peak of the CD8+ T-cell response.

scholarly journals Protein Vaccination Directs the CD4+ T Cell Response toward Shared Protective Epitopes That Can Be Recalled after Influenza Virus Infection

2019 ◽  
Vol 93 (20) ◽  
Author(s):  
Ajitanuj Rattan ◽  
Katherine A. Richards ◽  
Zackery A. G. Knowlden ◽  
Andrea J. Sant
Keyword(s):  
T Cells ◽  
Influenza Virus ◽  
T Cell ◽  
Virus Infection ◽  
Specific Antibody ◽  
Cell Response ◽  
Protective Immunity ◽  
Influenza Virus Infection ◽  
T Cell Response ◽  
Protein Vaccine

ABSTRACT Vaccination is widely used to generate protective immunity against influenza virus. CD4+ T cells contribute in diverse ways to protective immunity, most notably, in the provision of help for the production of neutralizing antibodies. Several recent reports have suggested that influenza virus infection elicits CD4+ T cells whose specificity only partially overlaps that of T cells elicited by vaccination. This finding has raised serious concerns regarding the utility of currently licensed inactivated influenza virus vaccines and novel protein-based vaccines. Here, using controlled animal models that allowed a broad sampling of the CD4+ T cell repertoire, we evaluated protein vaccine- versus infection-generated CD4+ T cell epitopes. Our studies revealed that all the infection-elicited CD4+ T cell epitope specificities are also elicited by protein vaccination, although the immunodominance hierarchies can differ. Finally, using a reverse-engineered influenza virus and a heterologous protein vaccination and infection challenge strategy, we show that protein vaccine-elicited CD4+ memory T cells are recalled and boosted after infection and provide early help to accelerate hemagglutinin (HA)-specific antibody responses. The early CD4+ T cell response and HA-specific antibody production are associated with lowered viral titers during the infection challenge. Our data lend confidence to the ability of current protein-based vaccines to elicit influenza virus-specific CD4+ T cells that can potentiate protective immunity upon influenza virus infection. IMPORTANCE Most current and new influenza vaccine candidates consist of a single influenza virus protein or combinations of influenza virus proteins. For these vaccines to elicit CD4+ T cells that can be recalled after infection, the peptide epitopes should be shared between the two modes of confrontation. Recently, questions regarding the relatedness of epitope selection by influenza virus infection and protein vaccination have been raised. However, the studies reported here show that the specificity of CD4+ T cells elicited by protein-based vaccines overlaps that of T cells elicited by infection and that CD4+ T cells primed by protein vaccines are recalled and contribute to protection of the host from a future infection.

scholarly journals VennVax, a DNA-prime, peptide-boost multi-T-cell epitope poxvirus vaccine, induces protective immunity against vaccinia infection by T cell response alone

Vaccine ◽  
2011 ◽  
Vol 29 (3) ◽  
pp. 501-511 ◽  
Author(s):  
Leonard Moise ◽  
R. Mark Buller ◽  
Jill Schriewer ◽  
Jinhee Lee ◽  
Sharon E. Frey ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Response ◽  
Protective Immunity ◽  
Cell Epitope ◽  
T Cell Response ◽  
T Cell Epitope
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