Immune Response to SARS-CoV-2 and Other Viruses
Research Tools and Resources
The immune system is complex and consists of a number of different immune cell subsets, each with unique characteristics and functions. When modeling or studying SARS-CoV-2 infection, it is important to choose efficient tools and technologies that can help fast-track learning about this new virus and, consequently, expedite the development of diagnostics, therapeutics, and vaccines. Explore below to find resources and tools for isolating and profiling immune cell subsets and quantifying biomarker levels when studying the immune response to SARS-CoV-2 and other viruses.
Sourcing and Isolating Immune Cells
To assess and measure the immune response in COVID-19 patients, experiments can be conducted on heterogeneous samples such as whole blood, peripheral blood mononuclear cells (PBMCs), or plasma.1,2
For accurate assessment and characterization of the immune response, COVID-19-positive samples need to be compared with healthy control samples. To reduce experimental uncertainty, ethically sourced human whole peripheral blood and leukopaks can be used as a source for isolating healthy control plasma or PBMCs. Alternatively, use cryopreserved PBMCs, T cells, and B cells for studying specific immune cell subsets.
When isolating PBMCs from healthy control or COVID-19-positive samples, standardizing the cell isolation process will reduce sample variability to ensure consistency of results. SepMate™ tubes can be used to standardize and simplify sample preparation by allowing users to quickly layer blood over density gradient media (e.g. Lymphoprep™) while preventing the layers from mixing.
Alternatively, immunomagnetic isolation techniques can be used to prepare samples. Deplete red blood cells (RBCs) from samples by using EasySep™ RBC Depletion Reagent, or isolate PBMCs directly from blood by using EasySep™ Direct Human PBMC Isolation Kit. When working with samples containing viruses or other infectious agents, immunomagnetic cell isolation can also be automated using RoboSep™ to minimize sample handling and reduce user risk.
Banerjee A et al. (2020) Isolation, sequence, infectivity, and replication kinetics of severe acute respiratory syndrome coronavirus 2. Emerg Infect Dis 26(9): 2054–63.
Scientists in Canada isolated SARS-CoV-2 from 2 infected patients and determined their genomic sequences. They then characterized the viruses’ ability to infect and replicate in human fibroblast, epithelial, and immune cells. By using primary human immune cells isolated with EasySep™, they were able to confirm that peripheral blood mononuclear cells are not permissive for SARS-CoV-2. This type of characterization study is critical to determine if the virus is evolving in its ability to infect human cells and cause severe disease as it spreads globally.
Hottz E et al. (2020) Platelet activation and platelet-monocyte aggregate formation trigger tissue factor expression in patients with severe COVID-19. Blood 136(11): 1330–41. Epub ahead of print, DOI: 10.1182/blood.2020007252.
Brazilian scientists investigated possible pathological mechanisms behind reports of a hypercoagulability state and thromboembolic complications in COVID-19 patients. By using platelets and monocytes isolated with EasySep™, researchers were able to demonstrate that increased platelet activation, platelet-monocyte aggregation, and tissue factor expression by monocytes were all associated with poor outcome in patients with severe COVID-19.
Products for Sourcing and Isolating Immune Cells
*For information about COVID-19 and primary cells, please see frequently asked questions (FAQ). Certain products are only available in select territories.
Characterizing Immune Cell Subsets
To gain a better understanding of disease pathogenesis when modeling or studying viral infections, it is important to isolate and accurately characterize relevant immune cell subsets and their activation states.
Early work on COVID-19 patients indicates lymphopenia with a substantial reduction in CD4+ T cells, CD8+ T cells, and total T cells.3 Others have reported that functional exhaustion of T cells and NK cells at the earlier stages of SARS-CoV-2 infection may contribute to a reduced ability to eliminate the virus, leading to disease progression.3,4 Neutrophils from COVID-19 patients display excessive neutrophil extracellular trap (NET) formation, which has been implicated in the formation of NET-containing microthrombi and is associated with increased disease severity.5 When studying immune cell exhaustion, EasySep™ can be used to isolate or enrich for NK cells and T cell subsets and ImmunoCult™ can be used for in vitro culture of human immune cells. Accurate characterization of immune cell subsets and their activation states by flow cytometric analysis can be achieved by choosing from a range of human- and mouse-reactive antibodies.
When immediate analysis is not possible following sample collection, storage and cryopreservation of cells is vital for maintaining sample quality, allowing you to continue your research when you're ready. A ready-to-use and chemically defined freezing media, such as CryoStor®, can be used for the cryopreservation of immune cells.
Products for Isolating and Characterizing T Cells
Products for Isolating and Characterizing NK Cells
Products for Isolating and Characterizing Neutrophils
Products for Isolating and Characterizing Dendritic Cells
*For differentiation of human monocytes into dendritic cells
*Medium for the culture and differentiation of human monocytes into dendritic cells and their maturation
*Supplement for the differentiation of human monocytes into dendritic cells
*Supplement for the maturation of human monocyte-derived dendritic cells
Products for Isolating and Characterizing Other Immune Cell Subsets
Measuring Immune Response Biomarkers
Enzyme-linked immunosorbent assays (ELISAs) use the concept of ligand-binding to quantify protein levels in biological samples such as plasma, serum, and cell culture supernatants.
After interacting with the ACE2 receptor and infecting lung epithelial cells, the SARS-CoV-2 virus evades and suppresses the immune response, allowing it to rapidly replicate in the host. This can result in a delayed initiation of the adaptive immune response and the creation of a cytokine storm, leading to immunopathogenesis.6 To quantify the inflammatory response following SARS-CoV-2 infection, choose highly sensitive ELISA kits for the detection and accurate quantification of cytokines and immunoglobulin protein levels in your samples.
Products for ELISA
Recombinant Spike, Nucleocapsid, and Human ACE2 Protein
Products for Targeting SARS-CoV-2 Nucleoprotein and Spike Protein
- Thevarajan I et al. (2020) Breadth of concomitant immune responses prior to patient recovery: A case report of non-severe COVID-19. Nat Med 26(4): 453–5.
- Wen W et al. (2020) Immune cell profiling of COVID-19 patients in the recovery stage by single-cell sequencing. Cell Discov 6: 31.
- Zheng H et al. (2020) Elevated exhaustion levels and reduced functional diversity of T cells in peripheral blood may predict severe progression in COVID-19 patients. Cell Mol Immunol 17(5): 541–3.
- Zheng M et al. (2020) Functional exhaustion of antiviral lymphocytes in COVID-19 patients. Cell Mol Immunol 17(5): 533–5.
- Middleton E et al. (2020) Neutrophil extracellular traps contribute to immunothrombosis in COVID-19 acute respiratory distress syndrome. Blood 136(10): 1169-79.
- Shi Y et al. (2020) COVID-19 infection: the perspectives on immune responses. Cell Death Differ 27(5): 1451–4.