scholarly journals Heterologous infection and vaccination shapes immunity against SARS-CoV-2 variants

Science ◽  
2022 ◽  
Vol 375 (6577) ◽  
pp. 183-192
Author(s):  
Catherine J. Reynolds ◽  
Joseph M. Gibbons ◽  
Corinna Pade ◽  
Kai-Min Lin ◽  
Diana Muñoz Sandoval ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Healthcare Workers ◽  
Cell Function ◽  
Natural Infection ◽  
Reliable Measure ◽  
Vaccine Responses ◽  
Domain Sequence ◽  
Variant Virus ◽  
The Subject

Immune imprinting For severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), immune responses to heterologous variants are influenced by a person’s infection history. Healthcare workers (HCWs) may be exposed to several doses and types of antigens, either by natural infection or by vaccination. Reynolds et al . studied a cohort of UK HCWs followed since March 2020. The immunological profiles of these people depended on how often the subject had encountered antigen and which variant was involved. Vaccine responses after infection were found to be less effective if the infection involved heterologous spike from a variant virus. Unfortunately, the N501Y spike mutation, found in many variants, seems to induce the regulatory T cell transcription factor FOXP3, indicating that the virus could subvert effective T cell function. Changes to antibody binding between variants also means that serology data using the Wuhan Hu-1 S1 receptor-binding domain sequence may not be a reliable measure of protection. —CA

scholarly journals Robust SARS-CoV-2-specific T-cell immunity is maintained at 6 months following primary infection

2020 ◽  
Author(s):  
Jianmin Zuo ◽  
Alex Dowell ◽  
Hayden Pearce ◽  
Kriti Verma ◽  
Heather Long ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Immune Responses ◽  
Antibody Level ◽  
Primary Infection ◽  
Natural Infection ◽  
T Cell Responses ◽  
Symptomatic Infection ◽  
Cell Responses ◽  
Cell Immunity

Abstract The immune response to SARS-CoV-2 is critical in both controlling primary infection and preventing re-infection. However, there is concern that immune responses following natural infection may not be sustained and that this may predispose to recurrent infection. We analysed the magnitude and phenotype of the SARS-CoV-2 cellular immune response in 100 donors at six months following primary infection and related this to the profile of antibody level against spike, nucleoprotein and RBD over the previous six months. T-cell immune responses to SARS-CoV-2 were present by ELISPOT or ICS analysis in all donors and are characterised by predominant CD4+ T cell responses with strong IL-2 cytokine expression. Median T-cell responses were 50% higher in donors who had experienced an initial symptomatic infection indicating that the severity of primary infection establishes a ‘setpoint’ for cellular immunity that lasts for at least 6 months. The T-cell responses to both spike and nucleoprotein/membrane proteins were strongly correlated with the peak antibody level against each protein. The rate of decline in antibody level varied between individuals and higher levels of nucleoprotein-specific T cells were associated with preservation of NP-specific antibody level although no such correlation was observed in relation to spike-specific responses. In conclusion, our data are reassuring that functional SARS-CoV-2-specific T-cell responses are retained at six months following infection although the magnitude of this response is related to the clinical features of primary infection.

scholarly journals Differential Immunogenicity of BNT162b2 or ChAdOx1 Vaccines After Extended-Interval Homologous Dual Vaccination in Older People

2021 ◽  
Author(s):  
Helen Parry ◽  
Rachel Bruton ◽  
Christine Stephens ◽  
Kevin Brown ◽  
Gayatri Amirthalingam ◽  
...  
Keyword(s):  
Immune Responses ◽  
Older People ◽  
Natural Infection ◽  
Cellular Responses ◽  
Antibody Responses ◽  
Vaccine Responses ◽  
Cell Responses ◽  
Boost Vaccine ◽  
The Uk ◽  
Cellular Immune

Abstract BackgroundSeveral SARS-CoV-2 vaccines have shown clinical efficacy against Covid-19 infection but there remains uncertainty about the immune responses elicited by different regimens. This is a particularly important question for older people who are at increased clinical risk following infection and in whom immune senescence may limit vaccine responses. The BNT162b2 mRNA and ChAdOx1 adenovirus vaccines were the first two vaccines deployed in the UK programme using an 8-12 week ‘extended interval’.ObjectivesWe undertook analysis of the spike-specific antibody and cellular immune response in 131 participants aged 80+ years after the second dose of ‘extended interval’ dual vaccination with either BNT162b2 mRNA (n=54) or ChAdOx1 (n=77) adenovirus vaccine. Blood samples were taken 2-3 weeks after second vaccine and were paired with samples taken at 5-weeks after first vaccine which have been reported previously. Antibody responses were measured using the Elecsys® electrochemiluminescence immunoassay assay and cellular responses were assessed by IFN-g ELISpot. ResultsAntibody responses against spike protein became detectable in all donors following dual vaccination with either vaccine. 4 donors had evidence of previous natural infection which is known to boost vaccine responses. Within the 53 infection-naïve donors the median antibody titre was 4030 U/ml (IQR 1892-8530) following BNT162b2 dual vaccination and 1405 (IQR 469.5- 2543) in the 74 patients after the ChAdOx1 vaccine (p=<0.0001). Spike-specific T cell responses were observed in 30% and 49% of mRNA and ChAdOx1 recipients respectively and median responses were 1.4-times higher in ChAdOx1 vaccinees at 14 vs 20 spots/million respectively (p=0.022).ConclusionDual vaccination with BNT162b2 or ChAdOx1 induces strong humoral immunity in older people following an extended interval protocol. Antibody responses are 2.9-times higher following the mRNA regimen whilst cellular responses are 1.7-times higher with the adenovirus-based vaccine. Differential patterns of immunogenicity are therefore elicited from the two vaccine platforms. It will be of interest to assess the relative stability of immune responses after these homologous vaccine regimens in order to assess the potential need for vaccine boosting. Furthermore, these findings indicate that heterologous vaccine platforms may offer the opportunity to further optimize vaccine responses.

scholarly journals Tumors induce de novo steroid biosynthesis in T cells to evade immunity

2018 ◽  
Author(s):  
Bidesh Mahata ◽  
Jhuma Pramanik ◽  
Louise van der Weyden ◽  
Krzysztof Polanski ◽  
Gozde Kar ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Tumor Immunity ◽  
Cell Function ◽  
Immune Cell ◽  
De Novo ◽  
Steroid Biosynthesis ◽  
Genetic Ablation ◽  
Tumor Immunosuppression

ABSTRACTTumors subvert immune cell function to evade immune responses, yet the complex mechanisms driving immune evasion remain poorly understood. Here we show that tumors induce de novo steroidogenesis in T lymphocytes to evade anti-tumor immunity. Using a novel transgenic steroidogenesis-reporter mouse line we identify and characterize de novo steroidogenic immune cells. Genetic ablation of T cell steroidogenesis restricts primary tumor growth and metastatic dissemination in mouse models. Steroidogenic T cells dysregulate anti-tumor immunity, and inhibition of the steroidogenesis pathway was sufficient to restore anti-tumor immunity. This study demonstrates T cell de novo steroidogenesis as a mechanism of anti-tumor immunosuppression and a potential druggable target.

scholarly journals Maternal fatty acid desaturase genotype correlates with infant immune responses at 6 months

2015 ◽  
Vol 114 (6) ◽  
pp. 891-898 ◽  
Author(s):  
Magdalena Muc ◽  
Eskil Kreiner-Møller ◽  
Jeppe M. Larsen ◽  
Sune Birch ◽  
Susanne Brix ◽  
...  
Keyword(s):  
T Cells ◽  
Fatty Acid ◽  
T Cell ◽  
Breast Milk ◽  
Immune Responses ◽  
Mononuclear Cells ◽  
Cell Function ◽  
Ex Vivo ◽  
Fatty Acid Desaturase ◽  
Cell Counts

AbstractBreast milk long-chain PUFA (LCPUFA) have been associated with changes in early life immune responses and may modulate T-cell function in infancy. We studied the effect of maternal fatty acid desaturase (FADS) genotype and breast milk LCPUFA levels on infants’ blood T-cell profiles and ex vivo-produced cytokines after anti-CD3/CD28 stimulation of peripheral blood mononuclear cells in 6-month-old infants from the Copenhagen Prospective Study of Asthma in Childhood birth cohort. LCPUFA concentrations of breast milk were assessed at 4 weeks of age, and FADS SNP were determined in both mothers and infants (n 109). In general, breast milk arachidonic acid (AA) levels were inversely correlated with the production of IL-10 (r −0·25; P=0·004), IL-17 (r −0·24; P=0·005), IL-5 (r −0·21; P=0·014) and IL-13 (r −0·17; P=0·047), whereas EPA was positively correlated with the counts of blood regulatory T-cells and cytotoxic T-cells and decreased T-helper cell counts. The minor FADS alleles were associated with lower breast milk AA and EPA, and infants of mothers carrying the minor allele of FADS SNP rs174556 had higher production of IL-10 (r −0·23; P=0·018), IL-17 (r −0·25; P=0·009) and IL-5 (r −0·21; P=0·038) from ex vivo-activated immune cells. We observed no association between T-cell distribution and maternal or infant FADS gene variants. We conclude that increased maternal LCPUFA synthesis and breast milk AA are associated with decreased levels of IL-5, IL-13 (type-2 related), IL-17 (type-17 related) and IL-10 (regulatory immune responses), but not with interferon-γ and TNF-α, which could be due to an effect of the maternal FADS variants on the offspring immune response transferred via breast milk LCPUFA.

Immunologic impact of anti-CTLA-4 therapy

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 3019-3019
Author(s):  
P. Sharma ◽  
D. Tsavachidou ◽  
A. Kamat ◽  
D. Ng Tang ◽  
H. Chen ◽  
...  
Keyword(s):  
Clinical Trial ◽  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Metastatic Disease ◽  
Cd4 T Cells ◽  
Cell Function ◽  
Cytotoxic T Lymphocyte ◽  
Systemic Circulation ◽  
Tumor Tissues

3019 Background: Blockade of the T-cell inhibitory molecule known as cytotoxic T lymphocyte antigen-4 (CTLA-4) results in antitumor responses. To date, trials have been conducted with over 4,000 patients with various malignancies in the metastatic disease setting, which allow for correlation of therapy with clinical outcome but do not provide analyses of relevant biomarkers in the systemic circulation that reflect changes within the tumor microenvironment. Approximately 10% of treated patients respond to therapy. Why some patients respond while others do not remains unknown. The identification of intermediate biomarkers are essential for us to understand whether anti-CTLA-4 antibody has “hit its target” to affect human immune responses and whether these identified immune responses can serve as predictive markers of clinical outcomes. Methods: We conducted a presurgical clinical trial with anti-CTLA-4 antibody. Patients with localized bladder cancer (N=10) were given two doses of antibody prior to undergoing surgery. Immunological analyses were conducted on patients’ tissues and blood samples. Results: Expression of the inducible costimulator (ICOS) molecule was increased on CD4 T cells within tumor tissues and systemic circulation. ICOS-expressing T-cells have not previously been reported to have a role in anti-tumor responses. We showed that CD4+ICOShi T cells produced IFNγ and could recognize the NY-ESO-1 tumor antigen. Pre- and post-therapy CD4 T cells were analyzed by reverse-phase protein array and microRNA array, which led to the identification of signaling pathways and regulatory mechanisms that play a role in enhanced T-cell function. Furthermore, murine models confirmed our initial findings and implied a role for ICOS-expressing T-cells in antitumor responses. Finally, we extended our findings to the metastatic disease setting of melanoma patients (N=14) and our preliminary data indicate an improved survival for anti-CTLA-4 treated patients who have a sustained increase in ICOS-expressing CD4 T cells. Conclusions: Our presurgical clinical trial allowed for the correlation of data from tumor tissues with data from peripheral blood, thus identifying ICOS-expressing T-cells as a relevant biomarker that can be used to monitor patients who receive anti-CTLA-4 therapy. [Table: see text]

Physical Interaction of Histone Deacetylase 6 (HDAC6) with STAT3 Regulates IL-10 Gene Expression and Immune Tolerance Mediated by Antigen-Presenting Cells (APCs)

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 829-829
Author(s):  
Fengdong Cheng ◽  
Zi Wang ◽  
Hongwei Wang ◽  
Maritza Lienlaf ◽  
Karrune V. Woan ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
Immune Responses ◽  
T Cell Activation ◽  
Cell Function ◽  
Conflicts Of Interest ◽  
Physical Interaction ◽  
Stat3 Phosphorylation ◽  
First Time

Abstract Abstract 829 APCs are critical in T-cell activation and in the induction of T-cell tolerance. Epigenetic modifications of specific genes in the APC play a key role in this process, and among them, histone deacetylases (HDACs) have emerged as key participants. HDAC6 is a 131 KDa protein with preferential cytoplasmic localization where it regulates the acetylation of proteins involved in cytoskeleton, cell-cell interaction and cell migration. Emerging evidence also implicates HDAC6 in regulation of immune responses, in particular at the level of the APC/T cell immune synapse1 and in the suppressive function of regulatory T-cells2. Expanding upon these immunoregulatory properties, here we show for the first time that HDAC6 physically interacts with STAT3, a transcriptional activator of IL-10 gene expression. By co-immunoprecipitation studies and confocal studies we found that HDAC6 co-localize with STAT3 in the cytoplasm and nuclei of macrophages. Furthermore, by using several HDAC6 and STAT3 mutants we have identified that the aminoacids 503–840 of HDAC6 and the STAT3 domain comprising aminoacids 465–585 are required for this interaction. Functionally, knocking down HDAC6 in a macrophage cell line (RAW264.7-HDAC6KD) resulted in inhibition of STAT3 phosphorylation, decreased recruitment of STAT3 to the IL-10 gene promoter and abrogation of IL-10 production by these cells in response to either LPS or IL-10. Similar results were observed in dendritic cells (DCs) or macrophages isolated from HDAC6 knock-out (KO) mice. Furthermore, HDAC6KD clones or APCs from HDAC6 KO mice displayed an enhanced expression of the co-stimulatory molecule B7.2 and are better activators of antigen-specific CD4+ T-cell responses in vitro. More importantly, these APCs are able of restoring the responsiveness of anergic T-cells from lymphoma-bearing mice. Pharmacologic inhibition of HDAC6 in APCs with Tubastatin A, an isotype-selective HDAC6 inhibitor, yielded similar enhancement of APC and T-cell function in vitro. Further support for HDAC6 as an appealing target in cancer immunotherapy has been recently provided by the significant delay in tumor growth observed in either HDAC6 KO mice or in wild type mice treated with Tubastatin A. In summary, we have shown for the first time that HDAC6 interacts physically with STAT3 and such an interaction is necessary for STAT3 phosphorylation and IL-10 gene expression in APCs. Disrupting the HDAC6/STAT3/IL-10 axis in APCs with selective HDAC6 inhibitors represents a novel approach to overcome tolerogenic pathways in these cells and tip the balance towards effective antitumor immune responses. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Myeloid-Derived Suppressor Cells Participate in Preventing Graft Rejection

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Yan Wang ◽  
Xiaodong Gu ◽  
Jianbin Xiang ◽  
Zongyou Chen
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Molecular Mechanisms ◽  
Cell Function ◽  
Suppressor Cells ◽  
Heterogeneous Population ◽  
Myeloid Derived Suppressor Cells ◽  
Transplant Tolerance ◽  
Pathological Conditions ◽  
T Cell Immune Responses

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells and have a tremendous potential to suppress immune responses. MDSCs accumulate during tumor progression, autoimmunity, chronic infection, transplantation, and other pathological conditions and can potently suppress T-cell function. Here, we discuss recent findings that describe the molecular mechanisms of MDSCs suppressing T-cell immune responses as well as recent observations that MDSCs may have roles in transplant tolerance.

scholarly journals Activated PIK3CD drives innate B cell expansion yet limits B cell–intrinsic immune responses

2018 ◽  
Vol 215 (10) ◽  
pp. 2485-2496 ◽  
Author(s):  
Michelle N. Wray-Dutra ◽  
Fahd Al Qureshah ◽  
Genita Metzler ◽  
Mohamed Oukka ◽  
Richard G. James ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
Immune Responses ◽  
B Cell ◽  
Plasma Cells ◽  
Recurrent Infection ◽  
Vaccine Responses ◽  
And Function ◽  
Natural Igm ◽  
The Impact

Activated PI3K-delta syndrome (APDS) is an immunodeficiency caused by gain-of-function mutations in PIK3CD. This disease exhibits complex immune phenotypes including increased IgM, recurrent infection, and impaired vaccine responses. To better understand the impact of B cells in this disease, we generated an inducible model of the common APDS mutation (hPIK3CD-E1021K; referred to as aPIK3CD) and intercrossed these mice with B cell–specific Cre models. Mb1-aPIK3CD mice exhibited bone marrow B lymphopenia and, conversely, expansion of the peripheral innate B1a and MZ B cell compartments. aPIK3CD B cells manifest increased pS6 and increased survival at several stages, without alterations in cycling, and baseline increases in plasma cells, natural IgM, and IgG3. Finally, Mb1-aPIK3CD mice exhibited blunted T cell–independent immune responses, and both AID- and CD21-aPIK3CD mice displayed reduced class-switched antibodies following T cell–dependent immunization. Thus, aPIK3CD alters B cell development and function and is counter-productive during immune responses, providing insight into B cell–intrinsic contributions to the APDS phenotype.

scholarly journals Vaccine protection from CD4+ T-cell loss caused by simian immunodeficiency virus (SIV) mac251 is afforded by sequential immunization with three unrelated vaccine vectors encoding multiple SIV antigens

2004 ◽  
Vol 85 (10) ◽  
pp. 2915-2924 ◽  
Author(s):  
Gerrit Koopman ◽  
Daniella Mortier ◽  
Sam Hofman ◽  
Henk Niphuis ◽  
Zahra Fagrouch ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Immune Responses ◽  
Simian Immunodeficiency Virus ◽  
Cell Function ◽  
Semliki Forest Virus ◽  
Rhesus Macaques ◽  
Cell Loss ◽  
Inverse Association ◽  
Immunodeficiency Virus

Candidate human immunodeficiency virus (HIV) vaccine strategies that induce strong cellular immune responses protect rhesus macaques that are infected with recombinant simian/human immunodeficiency virus SHIV89.6p from acute CD4+ T-cell loss and delay progression to AIDS. However, similar strategies have not proven as efficacious in the simian immunodeficiency virus (SIV)mac model of AIDS, an infection that causes a slow, steady loss of CD4+ T-cell function and numbers in rhesus macaques similar to that caused by HIV-1, the principal cause of AIDS in humans. Efforts to increase vaccine efficacy by repeated boosting with the same vector are quickly limited by rising anti-vector immune responses. Here, the sequential use of three different vectors (DNA, Semliki Forest virus and modified vaccinia virus Ankara) encoding the same SIVmac structural and regulatory antigens was investigated and demonstrated to prevent or slow the loss of CD4+ T-cells after mucosal challenge with the highly pathogenic SIVmac251 strain. Of particular interest was an inverse association between the extent of T-helper 2 cytokine responses and steady-state virus load. Although limited in the number of animals, this study provides important proof of the efficacy of the triple-vector vaccine strategy against chronic, progressive CD4+ T-cell loss in the rigorous SIVmac/rhesus macaque model of AIDS.

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