scholarly journals Cross-reactive CD4+ T cells enhance SARS-CoV-2 immune responses upon infection and vaccination

Science ◽  
2021 ◽  
pp. eabh1823
Author(s):  
Lucie Loyal ◽  
Julian Braun ◽  
Larissa Henze ◽  
Beate Kruse ◽  
Manuela Dingeldey ◽  
...  

The functional relevance of pre-existing cross-immunity to SARS-CoV-2 is a subject of intense debate. Here, we show that human endemic coronavirus (HCoV)-reactive and SARS-CoV-2-cross-reactive CD4+ T cells are ubiquitous but decrease with age. We identified a universal immunodominant coronavirus-specific spike peptide (S816-830) and demonstrate that pre-existing spike- and S816-830-reactive T cells were recruited into immune responses to SARS-CoV-2 infection and their frequency correlated with anti-SARS-CoV-2-S1-IgG antibodies. Spike-cross-reactive T cells were also activated after primary BNT162b2 COVID-19 mRNA vaccination displaying kinetics similar to secondary immune responses. Our results highlight the functional contribution of pre-existing spike-cross-reactive T cells in SARS-CoV-2 infection and vaccination. Cross-reactive immunity may account for the unexpectedly rapid induction of immunity following primary SARS-CoV-2 immunization and the high rate of asymptomatic/mild COVID-19 disease courses.

2021 ◽  
Author(s):  
Lucie Loyal ◽  
Julian Braun ◽  
Larissa Henze ◽  
Beate Kruse ◽  
Manuela Dingeldey ◽  
...  

While evidence for pre-existing SARS-CoV-2-cross-reactive CD4+ T cells in unexposed individuals is increasing, their functional significance remains unclear. Here, we comprehensively determined SARS-CoV-2-cross-reactivity and human coronavirus-reactivity in unexposed individuals. SARS-CoV-2-cross-reactive CD4+ T cells were ubiquitous, but their presence decreased with age. Within the spike glycoprotein fusion domain, we identified a universal immunodominant coronavirus-specific peptide epitope (iCope). Pre-existing spike- and iCope-reactive memory T cells were efficiently recruited into mild SARS-CoV-2 infections and their abundance correlated with higher IgG titers. Importantly, the cells were also reactivated after primary BNT162b2 COVID-19 mRNA vaccination in which their kinetics resembled that of secondary immune responses. Our results highlight the functional importance of pre-existing spike-cross-reactive T cells in SARS-CoV-2 infection and vaccination. Abundant spike-specific cross-immunity may be responsible for the unexpectedly high efficacy of current vaccines even with single doses and the high rate of asymptomatic/mild infection courses.


Immunity ◽  
2021 ◽  
Author(s):  
Mark M. Painter ◽  
Divij Mathew ◽  
Rishi R. Goel ◽  
Sokratis A. Apostolidis ◽  
Ajinkya Pattekar ◽  
...  

2021 ◽  
Author(s):  
Denise Lau ◽  
Sonal Khare ◽  
Derek Reiman ◽  
Tim Rand ◽  
Ameen A. Salahudeen ◽  
...  
Keyword(s):  
T Cells ◽  

2017 ◽  
Vol 3 (2) ◽  
pp. 28
Author(s):  
Desie Dwi Wisudanti

Kefir is a functional foodstuff of probiotics, made from fermented milk with kefir grains containing various types of beneficial bacteria and yeast. There have been many studies on the effects of oral kefir on the immune system, but few studies have shown the effect of bioactive components from kefir (peptides and exopolysaccharides/ kefiran), on immune responses. The purpose of this study was to prove the effect of kefir supernatant from milk goat on healthy immune volunteer response in vitro. The study was conducted on 15 healthy volunteers, then isolated PBMC from whole blood, then divided into 5 groups (K-, P1, P2, P3 and P4) before culture was done for 4 days. The harvested cells from culture were examined for the percentage of CD4+ T cells, CD8+ T cells, IFN-γ, IL-4 using flowsitometry and IL-2 levels, IL-10 using the ELISA method. The results obtained that kefir do not affect the percentage of CD4+ T cells and CD8+ T cells. The higher the concentration of kefir given, the higher levels of secreted IFN- γ and IL-4, but a decrease in IL-2 levels. Significant enhancement occurred at levels of IL-10 culture PBMC given kefir with various concentrations (p <0.01), especially at concentrations of 1%. These results also show the important effects of kefir bioactive components on immune responses. The conclusion of this study is that kefir can improve the immune response, through stimulation of IL-10 secretion in vitro.


2020 ◽  
Author(s):  
Xiaoyi Li ◽  
Qifan Zhang ◽  
Wanyue Zhang ◽  
Guofu Ye ◽  
Yanchen Ma ◽  
...  

Abstract Background: The restoration of host hepatitis B virus (HBV)-specific antiviral immunity is an effective strategy for hepatitis B recovery. Follicular dendritic cells (FDCs) play a crucial role in immune regulation. The goal of the present study was to investigate the characteristics and functions of FDCs in chronic HBV infection. Methods: The frequencies of FDCs in peripheral blood, liver, and spleen were measured in patients with chronic HBV infection. Isolated FDCs from splenic tissues of HBV-related liver cirrhosis-induced hypersplenism patients were cultured with autologous intrasplenic CD4 + T cells and CD19 + B cells.Results: We found that patients with chronic HBV infection had a significantly increased frequency of circulating FDCs compared with that of healthy controls. Additionally, the frequency of circulating FDCs was positively correlated with that of intrahepatic and intrasplenic counterparts. Moreover, a positive correlation between the frequency of circulating FDCs and plasmablast and memory B cells, as well as C-X-C motif chemokine receptor type 5 (CXCR5) + CD4 + T cells and CXCR5 + CD8 + T cells was also observed. Notably, in vitro experiments demonstrated that FDCs derived from splenic tissues of chronic HBV patients facilitated interferon-γ and interleukin-21 production from autologous intrasplenic CD4 + T cells and promoted the proliferation of autologous intrasplenic CD19 + B cells. Conclusions: Expanded FDCs in patients with chronic HBV infection may favor the host immune responses against HBV. The identification of this unique population may contribute to a better understanding of the immune regulatory mechanisms and provide a potential immunotherapeutic target in chronic HBV infection.


2006 ◽  
Vol 119 ◽  
pp. S183
Author(s):  
Sheraz Yaqub ◽  
Tone Bryn ◽  
Milada Mahic ◽  
Einar Aandahl ◽  
Kjetil Tasken

1993 ◽  
Vol 69 (3) ◽  
pp. 285-291 ◽  
Author(s):  
Audrey L. Fleming ◽  
Elizabeth H. Field ◽  
Naser Tolaymat ◽  
John S. Cowdery

2002 ◽  
Vol 76 (23) ◽  
pp. 11911-11919 ◽  
Author(s):  
Jie Zhang ◽  
Nicole Silvestri ◽  
J. Lindsay Whitton ◽  
Daniel E. Hassett

ABSTRACT Neonates are thought to mount less vigorous adaptive immune responses than adults to antigens and infectious agents. This concept has led to a delay in the administration of many currently available vaccines until late infancy or early childhood. It has recently been shown that vaccines composed of plasmid DNA can induce both humoral and cell-mediated antimicrobial immunity when administered within hours of birth. In most of these studies, immune responses were measured weeks or months after the initial vaccination, and it is therefore questionable whether the observed responses were actually the result of priming of splenocytes within the neonatal period. Here we show that DNA vaccination at birth results in the rapid induction of antigen-specific CD8+ T cells within neonatal life. Analyses of T-cell effector functions critical for the resolution of many viral infections revealed that neonatal and adult CD8+ T cells produce similar arrays of cytokines. Furthermore, the avidities of neonatal and adult CD8+ T cells for peptide and the rapidity with which they upregulate cytokine production after recall encounters with antigen are similar. Protective immunity against the arenavirus lymphocytic choriomeningitis virus, which is mediated by CD8+ cytotoxic T cells, is also rapidly acquired within the neonatal period. Collectively these data imply that, at least in the case of CD8+ T cells, neonates are not as immunodeficient as previously supposed and that DNA vaccines may be an effective and safe means of providing critical cell-mediated antiviral immunity extremely early in life.


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