scholarly journals Immunologic Responses against SARS-CoV-2

2020 ◽  
Vol 3 (2) ◽  
pp. 165-176
Author(s):  
Cássio Santana Meira ◽  
Vinícius Pinto Costa Rocha ◽  
Iasmim Diniz Orge ◽  
Danielle Devequi Gomes Nunes ◽  
Emanuelle de Souza Santos ◽  
...  

Coronavirus disease 2019 (COVID-19) emerged in Wuhan, China, in December 2019 and quickly spread worldwide becoming a global health problem unprecedented. The infection is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that is characterized as a RNA virus with an envelope derived from host cell with glycoprotein spikes, appearing like a crown-like external structure under electron microscope. Due to the aggressive spread profile of SARS-CoV-2, the scientific community is under pressure to generate knowledge about the morphology of the virus and the immune response against SARS-CoV-2, in order to generate useful information for the development of vaccines and methods of immunological diagnosis. Previous knowledge about other coronaviruses, such as SARS-CoV-1 and MERS-CoV, were the pillars for understanding the immune response of SARS-CoV-2. Until now, we know that the anti-SARS-CoV-2 immune response in the host involves mechanisms related to innate immunity, activation of CD4+ and CD8+ T cells and production of antibodies (IgA, IgG and IgM) against the virus. In spite of being a new pathogen, the literature on SARS-CoV-2 has increased dramatically in the past few months, especially in the immunology field. Here, we review the literature on SARS-CoV-2 immunology, focusing on the innate and adaptative immune responses.  

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.


2021 ◽  
Author(s):  
◽  
Sabine Kuhn

<p><b>The anti-tumour immune response is often not potent enough to prevent or eradicate disease. Dendritic cells (DCs) are professional antigen-presenting cells that are critical for the initiation of immune responses. While DCs frequently infiltrate tumours, lack of activation together with immuno-suppressive factors from the tumour can hamper an effective anti-tumour immune response.</b></p> <p>In this thesis, the ability of microbial stimuli and danger signals to overcome suppression and re-programme DCs and macrophages to an immuno-stimulatory phenotype was investigated. Whole live Mycobacterium smegmatis and BCG were used to provide multiple pathogen-associated molecular patterns. The intracellularly-recognised toll-like-receptor (TLR) ligands CpG and Poly IC, as well as the extracelullarly recognised TLR ligand LPS, and the danger signal monosodium-urate crystals (MSU) were also included.</p> <p>Bone-marrow derived DCs were found to respond to all adjuvants in vitro and DCs in tumour cell suspensions could be activated ex vivo. To assess the ability of adjuvants to enhance anti-tumour responses in vivo, immune-competent mice bearing established subcutaneous B16F1 melanomas were injected peri-tumorally with the different adjuvants. In line with previous reports, CpG treatment was effective in delaying tumour growth and increasing survival. A similar effect was found with Poly IC, but not with LPS, M. smegmatis, BCG or MSU alone. Combination of M. smegmatis + MSU, however, significantly delayed tumour growth and prolonged survival, while combinations of MSU + BCG or LPS were ineffective. Similar results were obtained using the B16.OVA melanoma and E.G7-OVA thymoma subcutaneous tumour models. In addition, Poly IC and MSU + M. smegmatis reduced primary tumour growth as well as lung metastases in the orthotopic 4T1 breast carcinoma model.</p> <p>Both Poly IC and MSU + M. smegmatis elicited an anti-tumour immune response that required CD8 T cells as well as NK cells. These treatments also resulted in increased proliferation of CD8 T cells and NK cells in tumour-draining lymph nodes, augmented infiltration of effector cells into the tumour, as well as enhanced production of in ammatory cytokines by effector cells and DCs in tumours. In addition, MSU + M. smegmatis also stimulated CD4 T cell proliferation, tumour-infiltrationand activation, while at the same time decreasing the frequency of regulatory T cells in tumours.</p> <p>Activation of a successful immune response to tumours was associated with early induction of IL-12 and IFNʸ, as well as moderate levels of pro-inflammatory cytokines at the tumour site and systemically. Furthermore, anti-tumour activity correlated with the induction of inflammatory monocyte-derived DCs in tumour-draining lymph nodes. These DCs were also observed in adjuvant treated tumours and their appearance was preceded by accumulation of inflammatory monocytes at the tumour site.</p> <p>These findings suggest that specific natural adjuvants can successfully modify the tumour environment and enhance the innate and adaptive anti-tumour immune response to delay tumour progression and increase survival.</p>


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Mauricio M. Rodrigues ◽  
Ana Carolina Oliveira ◽  
Maria Bellio

In the past ten years, studies have shown the recognition ofTrypanosoma cruzi-associated molecular patterns by members of the Toll-like receptor (TLR) family and demonstrated the crucial participation of different TLRs during the experimental infection with this parasite. In the present review, we will focus on the role of TLR-activated pathways in the modulation of both innate and acquired immune responses toT. cruziinfection, as well as discuss the state of the art of vaccine research and development against the causative agent of Chagas disease (or American trypanosomiasis).


2021 ◽  
Vol 10 (5) ◽  
pp. 1112
Author(s):  
Hyung Suk Kim ◽  
Byoung Kwan Son ◽  
Mi Jung Kwon ◽  
Dong-Hoon Kim ◽  
Kyueng-Whan Min

Background: Lysine-specific demethylase 1A (KDM1A) plays an important role in epigenetic regulation in malignant tumors and promotes cancer invasion and metastasis by blocking the immune response and suppressing cancer surveillance activities. The aim of this study was to analyze survival, genetic interaction networks and anticancer immune responses in breast cancer patients with high KDM1A expression and to explore candidate target drugs. Methods: We investigated clinicopathologic parameters, specific gene sets, immunologic relevance, pathway-based networks and in vitro drug response according to KDM1A expression in 456 and 789 breast cancer patients from the Hanyang university Guri Hospital (HYGH) and The Cancer Genome Atlas, respectively. Results: High KDM1A expression was associated with a low survival rate in patients with breast cancer. In analyses of immunologic gene sets, high KDM1A expression correlated with low immune responses. In silico flow cytometry results revealed low abundances of CD8+T cells and high programmed death-ligand 1 (PD-L1) expression in those with high KDM1A expression. High KDM1A expression was associated with a decrease in the anticancer immune response in breast cancer. In pathway-based networks, KDM1A was linked directly to pathways related to the androgen receptor signaling pathway and indirectly to the immune pathway and cell cycle. We found that alisertib effectively inhibited breast cancer cell lines with high KDM1A expression. Conclusions: Strategies utilizing KDM1A may contribute to better clinical management/research for patients with breast cancer.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Michael Lawrence Crichton ◽  
David Alexander Muller ◽  
Alexandra Christina Isabelle Depelsenaire ◽  
Frances Elizabeth Pearson ◽  
Jonathan Wei ◽  
...  

Abstract Micro-device use for vaccination has grown in the past decade, with the promise of ease-of-use, painless application, stable solid formulations and greater immune response generation. However, the designs of the highly immunogenic devices (e.g. the gene gun, Nanopatch or laser adjuvantation) require significant energy to enter the skin (30–90 mJ). Within this study, we explore a way to more effectively use energy for skin penetration and vaccination. These modifications change the Nanopatch projections from cylindrical/conical shapes with a density of 20,000 per cm2 to flat-shaped protrusions at 8,000 per cm2, whilst maintaining the surface area and volume that is placed within the skin. We show that this design results in more efficient surface crack initiations, allowing the energy to be more efficiently be deployed through the projections into the skin, with a significant overall increase in penetration depth (50%). Furthermore, we measured a significant increase in localized skin cell death (>2 fold), and resultant infiltrate of cells (monocytes and neutrophils). Using a commercial seasonal trivalent human influenza vaccine (Fluvax 2014), our new patch design resulted in an immune response equivalent to intramuscular injection with approximately 1000 fold less dose, while also being a practical device conceptually suited to widespread vaccination.


2021 ◽  
Author(s):  
◽  
Sabine Kuhn

<p><b>The anti-tumour immune response is often not potent enough to prevent or eradicate disease. Dendritic cells (DCs) are professional antigen-presenting cells that are critical for the initiation of immune responses. While DCs frequently infiltrate tumours, lack of activation together with immuno-suppressive factors from the tumour can hamper an effective anti-tumour immune response.</b></p> <p>In this thesis, the ability of microbial stimuli and danger signals to overcome suppression and re-programme DCs and macrophages to an immuno-stimulatory phenotype was investigated. Whole live Mycobacterium smegmatis and BCG were used to provide multiple pathogen-associated molecular patterns. The intracellularly-recognised toll-like-receptor (TLR) ligands CpG and Poly IC, as well as the extracelullarly recognised TLR ligand LPS, and the danger signal monosodium-urate crystals (MSU) were also included.</p> <p>Bone-marrow derived DCs were found to respond to all adjuvants in vitro and DCs in tumour cell suspensions could be activated ex vivo. To assess the ability of adjuvants to enhance anti-tumour responses in vivo, immune-competent mice bearing established subcutaneous B16F1 melanomas were injected peri-tumorally with the different adjuvants. In line with previous reports, CpG treatment was effective in delaying tumour growth and increasing survival. A similar effect was found with Poly IC, but not with LPS, M. smegmatis, BCG or MSU alone. Combination of M. smegmatis + MSU, however, significantly delayed tumour growth and prolonged survival, while combinations of MSU + BCG or LPS were ineffective. Similar results were obtained using the B16.OVA melanoma and E.G7-OVA thymoma subcutaneous tumour models. In addition, Poly IC and MSU + M. smegmatis reduced primary tumour growth as well as lung metastases in the orthotopic 4T1 breast carcinoma model.</p> <p>Both Poly IC and MSU + M. smegmatis elicited an anti-tumour immune response that required CD8 T cells as well as NK cells. These treatments also resulted in increased proliferation of CD8 T cells and NK cells in tumour-draining lymph nodes, augmented infiltration of effector cells into the tumour, as well as enhanced production of in ammatory cytokines by effector cells and DCs in tumours. In addition, MSU + M. smegmatis also stimulated CD4 T cell proliferation, tumour-infiltrationand activation, while at the same time decreasing the frequency of regulatory T cells in tumours.</p> <p>Activation of a successful immune response to tumours was associated with early induction of IL-12 and IFNʸ, as well as moderate levels of pro-inflammatory cytokines at the tumour site and systemically. Furthermore, anti-tumour activity correlated with the induction of inflammatory monocyte-derived DCs in tumour-draining lymph nodes. These DCs were also observed in adjuvant treated tumours and their appearance was preceded by accumulation of inflammatory monocytes at the tumour site.</p> <p>These findings suggest that specific natural adjuvants can successfully modify the tumour environment and enhance the innate and adaptive anti-tumour immune response to delay tumour progression and increase survival.</p>


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2197-2197
Author(s):  
Jose M. Rojas ◽  
Katy Knight ◽  
Li-Hui Wang ◽  
Richard E. Clark

Abstract Chronic myeloid leukaemia (CML) is characterised by the BCR-ABL oncoprotein. The amino-acid sequences spanning the junctional region are completely leukaemia-specific. In vitro pulsing of antigen presenting cells elicits immune response to CML cells. Vaccination of CML patients with peptides from this junctional region could therefore elicit/augment immune responses to CML cells. In our Evaluation of Peptide Immunisation in CML (EPIC) study, the patient’s entry requirements were as follows: first chronic phase of CML, expression of e14a2 (b3a2) BCR-ABL transcript, and prior treatment with imatinib daily (at least 400mg) at a stable dose for at least 6 months. Each patient received intradermally a cocktail of 3 BCR-ABL peptides: a 9-mer spanning the e14a2 region, the same 9-mer linked to PADRE (a 15-mer non-natural peptide shown to activate CD4+ T cells), and a 13-mer consensus e14a2 junctional peptide linked to PADRE. Peptides were administered at either 100 (5 patients), 300 (5 patients), 600 (5 patients), or 1000μg (4 patients) with sargramostim on 6 occasions over 2 months. Immune responses to the vaccine were monitored by IFN-γ and IL-5 ELISPOT assays on peripheral blood mononuclear cells. Molecular responses were assessed by quantitative real-time PCR of BCR-ABL mRNA. At entry no patient showed a detectable immune response to PADRE, but all 19 patients had detectable CD4+ T cells responses within 3 months of commencing vaccination. This indicated that the vaccination protocol was capable of stimulating T cell responses in all 19 patients. Immune responses to the 9-mer BCR-ABL junctional peptide used in the vaccine were detected in 11/19 patients, and demonstrated to be CD8+ T cells by cytokine analysis in flow cytometry. BCR-ABL immune responses were also assessed against a longer 18-mer peptide spanning the whole e14a2 junctional region. CD4+ T cells specific for this 18-mer peptide were detected in 14/19 patients. Interestingly, immunophenotyping indicated that these BCR-ABL-specific T cells were of a memory phenotype (CD45RO+). Serial molecular responses were available for at least 12 months on all cases. Of the 6 patients not in major cytogenic response (MCR) at baseline, molecular improvement was only observed in one case. However 12/13 patients in at least MCR at baseline had at least a 1 log fall in BCR–ABL transcripts, though this occurred several months after completing vaccination. Moreover, vaccination improved the fall in BCR–ABL transcripts in patients who had received imatinib for more than 12 months. These data show that peptide immunisation in CML can elicit anti-BCR-ABL peptide responses in CD4+ and CD8+ T cells. It also demonstrates that BCR-ABL peptide vaccination may improve control of CML, especially in patients responding well to imatinib.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1837-1837
Author(s):  
Suresh Veeramani ◽  
George J. Weiner

Abstract Background Proteins within the complement system have complex effects on cellular immune responses. In previous studies, we found that active complement components, especially C5a, can dampen the development of antigen-specific immune responses following vaccination with a model antigen, in part by promoting generation of APC-induced T regulatory (Treg) cells. These studies also demonstrated that B lymphoma cell lines exposed to complement can induce Treg generation in vitro. The current study was designed to address whether depletion of C5a could enhance development of a cellular anti-lymphoma immune response in vivo. Methods Immunocompetent Balb/C mice were inoculated subcutaneously with syngeneic A20 B lymphoma cells mixed with either 10 μg of rat anti-mouse C5a monoclonal antibody (mAb) or 10 μg of isotype-matched Rat IgG2a control mAb. Tumor growth was followed. In select experiments, mice were sacrificed and analyzed for the percentage and activity of tumor-infiltrating T cells and A20-specific splenic T cell responses. Results 1. Tumor progression. Lymphoma grew more slowly in mice treated with anti-C5a mAb compared to mice treated with control mAb (p<0.05) {Fig. 1). 2. Intratumoral T cells. Tumors from mice treated with anti-C5a mAb had higher CD8+ T cell infiltration compared to mice treated with control mAb (p=0.002) (Fig. 2). Tumor-infiltrating CD8+ T cells showed a trend towards higher intracellular IFNg production in mice treated with anti-C5a mAb compared to control mAb (p=0.051). 3. Splenic T cells. Splenic T cells from mice treated with anti-C5a mAb produced IFNg to a greater degree than did splenic T cells from control mice when splenocytes were cultured with irradiated A20 cells in vitro (p=0.041) (Fig. 3). There was a trend towards decreased numbers of splenic CD4+CD25highFoxp3+ Tregs in C5a-depleted mice compared to control mice. Conclusions Depletion of C5a at the site of tumor inoculation slows tumor growth and increases the number of tumor infiltrating CD8 T cells in a syngenic immunocompetent model of lymphoma. A trend towards enhanced production of IFNg in the tumor infiltrating T cells, increased numbers of tumor-specific splenic T cells, and reduced numbers of splenic Tregs, suggests intratumoral C5a depletion can enhance tumor-specific immune responses both within the tumor and systemically. Ongoing studies are exploring the molecular mechanisms involved in C5a-promoted tumor progression and the use of C5a depletion as a novel strategy to improve anti-tumor immunity. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4114-4114
Author(s):  
Silvio Antoniak ◽  
Kohei Tatsumi ◽  
Nigel Mackman

Abstract Introduction: Co-regulation of the immune response and the coagulation cascade after infection is thought to be an ancient response to limit pathogen spread. Recently, we showed that activation of the thrombin receptor, protease-activated receptor 1 (PAR1), on fibroblasts enhanced the innate immune responses to RNA virus infection. Here, we investigated whether PAR1 activation by the extrinsic coagulation pathway contributes to dsRNA-induced innate immune responses in macrophages. Methods: Activation of the type-I interferon (IFN) pathway in the murine macrophage cell line RAW264.7 and bone-marrow derived macrophages (BMDM) from WT and PAR1-/- was analyzed after dsRNA (poly I:C) and/or PAR-1 stimulation. In addition, innate immune responses in the spleen were analyzed in vivo 4 hours after poly I:C (8mg/kg) injection in mice with reduced tissue factor expression (LowTF) or global PAR1 deletion (PAR1-/-) as well as in WT mice with a thrombin inhibitor (dabigatran etexilate, 10g/kg chow) or PAR-1 inhibitor (SCH79797, 25μg/kg). Lastly, we investigated the innate immune response in the spleen of WT and PAR1-/-mice after infection with the single-stranded RNA virus coxsackievirus B3. Results: RAW264.7 and BMDM exhibited a toll-like receptor 3 dependent induction of IFNβ and CXCL10 after poly I:C stimulation. Activation of PAR-1 with either thrombin or agonist peptide enhanced poly I:C induction of IFNβ and CXCL10. A deficiency of tissue factor levels, thrombin inhibition, PAR-1 inhibition or PAR1 deficiency resulted in reduced expression levels of type-I IFNs and IFN-response genes such as CXCL10 in the spleen and plasma in mice given poly I:C. Last, PAR1-/-mice exhibited impaired IFNβ immune response 4 days after coxsackievirus B3 infection compared to WT mice. Conclusion: Our study indicates that the coagulation dependent activation of PAR1 on macrophages is important for anti-viral responses to dsRNA. We speculate that PAR1 inhibition may interfere with anti-viral responses in humans. Disclosures No relevant conflicts of interest to declare.


2006 ◽  
Vol 26 (1) ◽  
pp. 8-25 ◽  
Author(s):  
Michelle L. McCully ◽  
Joaquín Madrenas

During the past few years, there has been a substantial increase in the understanding of innate immunity. Dendritic cells are emerging as key players in the orchestration of this early phase of immune responses, with a role that will translate into the subsequent type of adaptive immune response against infection. Here we provide an overview of dendritic cell differentiation and function, with particular emphasis on those features unique to the immune defense of the peritoneal cavity and in the context of peritoneal dialysis-associated immune responses. The reader is referred to the primary references included in the accompanying list for specific details in this fascinating field.


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