scholarly journals A glimpse into the diverse cellular immunity against SARS-CoV-2 

2020 ◽  
Author(s):  
Lung-Ji Chang ◽  
Cheng-Wei Chang ◽  
Yuchen Liu ◽  
Cheng Jiao ◽  
Hongwei Liu ◽  
...  

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific cellular immune response may prove to be essential for long-term immune protection against the novel coronavirus disease 2019 (COVID-19). To assess COVID-19-specific immunity in the population, we synthesized selected peptide pools of SARS-CoV-2 structural and functional proteins, including Spike (S), Membrane (M), envelope (E), Nucleocapsid (N) and Protease (P) as target antigens. Survey of the T cell precursur frequencies in healthy individuals specific to these viral antigens demonstrated a diverse cellular immunity, including high, medium, low and no responders. This was further confirmed by in vitro induction of anti-SARS-CoV-2 T cell immune responses using dendritic cell (DC)/T cell coculture, which was consistent with the corresponding T cell precursor frequencies in each individual tested. In general, the combination of all five antigenic pools induced the strongest cellular immune response, and individual donors responded differently to different viral antigens. Importantly, a secondary in vitro booster stimulation of the T cells with the DC-peptides induced increased anti-viral immune responses in all individuals even in the no responders, suggesting that booster immunization in a vaccine scheme may elicit a broad protection in immune naïve population. Our analysis illustrates the critical role of cellular immunity in fighting COVID-19 and the importance of analyzing anti-SARS-CoV-2 T cell response in addition to antibody response in the population.

2021 ◽  
Author(s):  
Cheng-Wei Chang ◽  
Yuchen Liu ◽  
Cheng Jiao ◽  
Hongwei Liu ◽  
Xiaochuan Chen ◽  
...  

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific cellular immune response may prove to be essential for long-term immune protection against the novel coronavirus disease 2019 (COVID-19). To assess COVID-19-specific immunity in the population, we synthesized selected peptide pools of SARS-CoV-2 structural and functional proteins, including Spike (S), Membrane (M), Envelope (E), Nucleocapsid (N) and Protease (P) as target antigens. Survey of the T cell precursur frequencies in healthy individuals specific to these viral antigens demonstrated a diverse cellular immunity, including high, medium, low and no responders. This was further confirmed by in vitro induction of anti-SARS-CoV-2 T cell immune responses using dendritic cell (DC)/T cell coculture, which supported the corresponding T cell precursor frequencies in each of the individuals tested. In general, the combination of all five viral antigen pools induced the strongest cellular immune response, yet individual donors responded differently to different viral antigens. Importantly, in vitro restimulation of the T cells with the DC-peptides induced increased anti-viral immune responses in all individuals even in the no responders, suggesting that repeated antigen stimulation could elicit a broad protection in immune naïve population. Our analysis recapitulates the critical role of cellular immunity in fighting COVID-19 and the importance of analyzing anti-SARS-CoV-2 T cell response in addition to antibody response in the population.ImportanceFacing the rapid evolving SARS-CoV-2 variants in the world, current emphasis on antibody-producing vaccines needs a quick revisit. The virus-specific cellular immunity may prove to be essential for long-term protection against COVID-19. This study designed a series of antigenic peptides encompassing the conserved and/or essential domains of Spike (S), Membrane (M), envelope (E), Nucleocapsid (N) and Protease (P) as targets to assess Covid-19-specific immunity in the population. The results demonstrated a diverse cellular immunity, including high, medium, low and no responders. This was verified by in vitro generation of anti-SARS-CoV-2 T-cells from these subjects. The study suggested that individuals responded differently to the different viral antigens, and importantly, repeated stimulation could produce virus specific T cells in all individuals, including the no responders. This study illustrates the needs for assessing anti-viral cellular immunity in addition to antibody response in the general population.


2005 ◽  
Vol 79 (24) ◽  
pp. 15107-15113 ◽  
Author(s):  
Judith H. Aberle ◽  
Stephan W. Aberle ◽  
Regina M. Kofler ◽  
Christian W. Mandl

ABSTRACT A new vaccination principle against flaviviruses, based on a tick-borne encephalitis virus (TBEV) self-replicating noninfectious RNA vaccine that produces subviral particles, has recently been introduced (R. M. Kofler, J. H. Aberle, S. W. Aberle, S. L. Allison, F. X. Heinz, and C. W. Mandl, Proc. Natl. Acad. Sci. USA 7:1951-1956, 2004). In this study, we evaluated the potential of the self-replicating RNA vaccine in mice in comparison to those of live, attenuated vaccines and a formalin-inactivated whole-virus vaccine (ImmunInject). For this purpose, mice were immunized using gene gun-mediated application of the RNA vaccine and tested for CD8+ T-cell responses, long-term duration, neutralizing capacity, and isotype profile of specific antibodies and protection against lethal virus challenge. We demonstrate that the self-replicating RNA vaccine induced a broad-based, humoral and cellular (Th1 and CD8+ T-cell response) immune response comparable to that induced by live vaccines and that it protected mice from challenge. Even a single immunization with 1 μg of the replicon induced a long-lasting antibody response, characterized by high neutralizing antibody titers, which were sustained for at least 1 year. Nevertheless, it was possible to boost this response further by a second injection with the RNA vaccine, even in the presence of a concomitant CD8+ T-cell response. In this way it was possible to induce a balanced humoral and cellular immune response, similar to infection-induced immunity but without the safety hazards of infectious agents. The results also demonstrate the value of TBEV replicon RNA for inducing protective long-lasting antiviral responses.


2021 ◽  
Author(s):  
Simon Faissner ◽  
Neele Heitmann ◽  
Ricarda Rohling ◽  
Ulas Ceylan ◽  
Marielena Bongert ◽  
...  

Abstract The SARS-CoV-2 pandemic has tremendous implications for the management of patients with autoimmune conditions such as multiple sclerosis (MS) under immune therapies targeting CD20+ B cells (aCD20). We here investigated humoral and cellular immune responses, including neutralization against SARS-CoV-2 WT and delta variant and T cell responses of aCD20-treated MS patients following SARS-CoV-2 vaccination compared to healthy controls. aCD20-treated MS patients had lower anti-SARS-CoV-2-Spike titers, which correlated with B-cell repopulation. Sera of aCD20 treated patients had reduced capacity to neutralize WT and delta pseudoviruses in vitro. On the contrary, aCD20 treated patients elicited higher frequencies of CD3+ T cells, Th1 cells, Th2 cells, Tc1 cells and CD8+IFN-γ+IL-2+ cells. In summary, aCD20 treated patients have a reduced humoral immune response, depending on B cell repopulation, in accordance with a shift of cellular immune response to a stronger Th1, Th2 and Tc1 phenotype, suggesting strong cellular protection against SARS-CoV-2.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 5016-5016 ◽  
Author(s):  
Emmanuel S. Antonarakis ◽  
Adam S Kibel ◽  
George Adams ◽  
Lawrence Ivan Karsh ◽  
Aymen Elfiky ◽  
...  

5016 Background: ADT is a standard treatment for men with BRPC after failure of local therapy, and has immunomodulatory effects. Sipuleucel-T is an autologous cellular immunotherapy approved for asymptomatic/minimally symptomatic metastatic castrate resistant prostate cancer. The STAND trial (NCT01431391) aimed to evaluate optimal sequencing of sipuleucel-T and ADT in men with BRPC at high risk for metastases (ie PSA doubling time ≤12 mo). Methods: Men were randomized (1:1) to Arm 1: sipuleucel-T followed by ADT (2 wks after 3rd infusion); or Arm 2: ADT (3 mo lead in) followed by sipuleucel-T. All men had 3 doses of sipuleucel-T and 12 mo of ADT (45 mg leuprolide SQ at 6 mo intervals). The primary endpoint is cellular immune response (ELISPOT to PA2024 [PAP-GMCSF]). Secondary endpoints are humoral and cytokine responses, product parameters and safety. Results: 68 men were randomized. Preliminary data show higher levels of serum cytokines in Arm 2 vs Arm 1, with a pattern suggesting a mixed TH1/TH2 cellular immune response; elevations were seen in TH1 (IFNγ, IL 12), TH2 (IL 4, 5, 10, 13) and TH17 (IL 17) subsets (all P<.05). The increase in TH1 cytokines was consistent with a trend toward higher PA2024-specific ELISPOT responses 2 wk after the 3rd sipuleucel-T infusion in Arm 2 vs Arm 1 (40.5 vs 12.8 spots; P=.086), suggesting increased T cell activation in Arm 2. Antigen-specific humoral responses were induced in both arms with no differences yet observed between arms. Sipuleucel-T product parameters were roughly equivalent in both arms with APC activation data indicating a robust prime-boost effect. Conclusions: While confirmation is required, these preliminary data suggest that tumor-specific T cell responses and broad based immune responses are augmented when sipuleucel-T is given after rather than before ADT initiation. These data are consistent with preclinical studies showing that ADT enhances T cell activity, and provide preliminary evidence that combining ADT with sipuleucel-T may augment adaptive immunity. Further follow up will determine whether augmented immune responses correlate with clinical parameters (eg PSA recurrence). Clinical trial information: NCT01431391.


2021 ◽  
Author(s):  
Yunmei Huang ◽  
Yuting Yang ◽  
Tingting Wu ◽  
Zhiyu Li ◽  
Yao Zhao

Abstract Background: Hepatitis B vaccination is the most cost-effective way to prevent HBV infection. Currently, hepatitis B vaccine (HepB) efficacy was usually assessed by anti-HBs level, but there were little comprehensive analyses of humoral and cellular immune response to HepB in children after neonatal immunization. Methods: A total of 145 children with primary hepatitis B immunization history were involved in this study to evaluate the efficacy of HepB. Blood samples were obtained from 80 eligible children before one dose of HepB booster and 41 children post-booster. Children with anti-HBs at a low level (<10mIU/mL and [10,100) mIU/mL) were received one dose of HepB booster after informed consent. Subjects were be measured anti-HBs, HBsAg-specific T cell responses and frequency of B cell subsets before and after booster. Results: Among 80 subjects, 81.36% of children showed both T cell and anti-HBs responses positive at baseline. After one dose of booster, anti-HBs titer (P<0.0001), positive rate of HBsAg-specific T cell response (P=0.0036) and magnitude of SFCs (P=0.0003) increased significantly. Comparing preexisting anti-HBs titer <10mIU/mL with anti-HBs titer [10,100) mIU/mL, anti-HBs response (P=0.0005) and HBsAg-specific T lymphocyte response (P<0.0001) increased significantly. The change tendency of HBV specific humoral response is complementary to T cellular response with age. Conclusion: Protection from primary HBV immunization persists long on account of the complementary presence of HBV-specific humoral and T-cellular immune response. One dose of HepB booster is efficient enough to produce protective anti-HBs and enhance HBsAg-specific T cell response. In the HBV endemic areas, HepB booster immunization is still the most economical and effective way to prevent HBV infection, especially in children without anti-HBs.


2006 ◽  
Vol 75 (1) ◽  
pp. 104-112 ◽  
Author(s):  
Lorenzo Giacani ◽  
Barbara Molini ◽  
Charmie Godornes ◽  
Lynn Barrett ◽  
Wesley Van Voorhis ◽  
...  

ABSTRACT Transcriptional analysis of the tpr genes in Treponema pallidum subsp. pallidum (referred to here as simply T. pallidum) has been limited to date, and yet the expression of members of this gene family is likely relevant to the pathogenesis of syphilis. Recently, immunological studies and semiquantitative mRNA analysis led to the hypothesis of the modulation of tpr gene transcription during infection and suggested that various strains of T. pallidum might differentially express these genes. In this study we developed a real-time amplification assay to quantify the tpr mRNAs with respect to the 47-kDa lipoprotein message and to compare transcript levels among four different strains of T. pallidum. In addition, we analyzed the lymphocyte responsiveness pattern toward the Tpr antigens in late experimental syphilis to identify tpr genes that had been expressed during the course of infection. The T-cell response has been implicated in clearance of treponemes from early lesions, and some of the Tprs were identified as strong targets of the cellular immune response. We show that message for many of the tpr genes can be detected in treponemes harvested at the peak of early infection. Interestingly, tprK seems to be preferentially expressed in almost every strain, and it is uniformly the target of the strongest cellular immune response. These studies demonstrate the differential expression of certain tpr genes among strains of T. pallidum, and further studies are needed to explore the relationship between tpr gene expression and the clinical course of syphilis in infected individuals.


2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
S. Viganò ◽  
M. Perreau ◽  
G. Pantaleo ◽  
A. Harari

The immune system has evolved to allow robust responses against pathogens while avoiding autoimmunity. This is notably enabled by stimulatory and inhibitory signals which contribute to the regulation of immune responses. In the presence of a pathogen, a specific and effective immune response must be induced and this leads to antigen-specific T-cell proliferation, cytokines production, and induction of T-cell differentiation toward an effector phenotype. After clearance or control of the pathogen, the effector immune response must be terminated in order to avoid tissue damage and chronic inflammation and this process involves coinhibitory molecules. When the immune system fails to eliminate or control the pathogen, continuous stimulation of T cells prevents the full contraction and leads to the functional exhaustion of effector T cells. Several evidences bothin vitroandin vivosuggest that this anergic state can be reverted by blocking the interactions between coinhibitory molecules and their ligands. The potential to revert exhausted or inactivated T-cell responses following selective blocking of their function made these markers interesting targets for therapeutic interventions in patients with persistent viral infections or cancer.


Vaccines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 827
Author(s):  
Cheng-Wei Chang ◽  
Yuchen Liu ◽  
Cheng Jiao ◽  
Hongwei Liu ◽  
Jie Gong ◽  
...  

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific cellular immune response has been shown to play a critical role in preventing severe illness or death in patients infected with SARS-CoV-2 or its variants. Given the multiple T-cell epitopes shared by wild-type virus and its variants, we hypothesized that vaccines that target multiple T-cell epitopes of SARS-CoV-2 may provide a “universal protection” against the wild-type virus as well as its variants, even the heavily mutated ones. To test this, we assessed SARS-CoV-2-specific T-cell precursors in healthy individuals using overlapping peptide pools of SARS-CoV-2 structural and functional proteins, including spike (S), membrane (M), envelope (E), nucleocapsid (N), and protease (P) proteins as target antigens. Diverse T-cell precursor frequencies specific to these viral antigens were detected in healthy individuals, including high, medium, low, and no responders. This was further confirmed by efficient induction of anti-SARS-CoV-2 T-cell immune responses using ex vivo dendritic cell (DC)/T cell coculture. The results demonstrated T-cell responses consistent with the precursor frequencies of each of the individuals tested. Importantly, the combination of all five viral peptide pools induced the strongest cellular immune response, and further, after a DC-peptides re-stimulation, even the no responders developed an increased anti-viral T-cell response. These analyses recapitulate the presence of a broad anti-SARS-CoV-2 cellular immunity even in an immune naïve population, which could be enhanced by antigen presenting cells presenting the overlapping antigenic peptides. Given the critical role of cellular immunity in COVID-19 protection, these results have important implications for vaccine design and immunotherapy in fighting SARS-CoV-2 and its variants.


2021 ◽  
Author(s):  
Damon H. May ◽  
Benjamin E. R. Rubin ◽  
Sudeb C. Dalai ◽  
Krishna Patel ◽  
Shahin Shafiani ◽  
...  

The Omicron SARS-CoV-2 variant contains 34 mutations in the spike gene likely impacting protective efficacy from vaccines. We evaluated the potential impact of these mutations on the cellular immune response. Combining epitope mapping to SARS-CoV-2 vaccines that we have determined from past experiments along with T cell receptor (TCR) repertoire sequencing from thousands of vaccinated or naturally infected individuals, we estimate the abrogation of the cellular immune response in Omicron. Although 20% of CD4+ T cell epitopes are potentially affected, the loss of immunity mediated by CD4+ T cells is estimated to be slightly above 30% as some of the affected epitopes are relatively more immunogenic. For CD8+ T cells, we estimate a loss of approximately 20%. These reductions in T cell immunity are substantially larger than observed in other widely distributed variants. Combined with the expected substantial loss of neutralization from antibodies, the overall protection provided by SARS-CoV-2 vaccines could be impacted adversely. From analysis of prior variants, the efficacy of vaccines against symptomatic infection has been largely maintained and is strongly correlated with the T cell response but not as strongly with the neutralizing antibody response. We expect the remaining 70% to 80% of on-target T cells induced by SARS-CoV-2 vaccination to reduce morbidity and mortality from infection with Omicron.


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