Immune Response to SARS-CoV-2 and Other Viruses

Research Tools and Resources

Immune Response to Viral Infection

Defining the immune response to SARS-CoV-2 infection is key to understanding the disease pathogenesis of COVID-19 and can aid in the development of diagnostic tests, vaccines, and other therapeutics.

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.

Key Publications

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


Source of Serum, PBMCs, and Immune Cells
Catalog #
Human Whole Peripheral Blood*
Source of PBMCs and Immune Cells
Catalog #
Human Peripheral Blood Leukopak, Fresh*
Human Peripheral Blood Leukopak, Frozen*
LRS Cone*
Ethically Sourced Frozen Primary Cells
Catalog #
Human Peripheral Blood Mononuclear Cells, Frozen
Human Peripheral Blood Pan-T Cells, Frozen
Human Peripheral Blood CD4+ T Cells, Frozen
Human Peripheral Blood CD8+ T Cells, Frozen
Human Peripheral Blood B Cells, Frozen
Human Peripheral Blood CD19+ B Cells, Frozen
Human Peripheral Blood CD19+CD27- Naïve B Cells, Frozen

*For information about COVID-19 and primary cells, please see frequently asked questions (FAQ). Certain products are only available in select territories.

See all primary human cell products >

Tools for PBMC Isolation
Catalog #
SepMate™ PBMC Isolation Tubes
85415, 86415 (15 mL)
85450, 86450 (50 mL)
Lymphoprep™
EasySep™ Direct Human PBMC Isolation Kit
EasySep™ RBC Depletion Reagent
RoboSep™-S
*For fully automated cell separations
Tools for Plasma Isolation
Catalog #
SepMate™
85415, 86415 (15 mL)
85450, 86450 (50 mL)
Lymphoprep™
EasySep™ RBC Depletion Reagent

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 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.

Learn more about our cell storage media >

Products for Isolating and Characterizing T Cells


Isolation of T Cells
Catalog #
EasySep™ T Cell Isolation Kit
17951 (Human)
19851 (Mouse)
EasySep™ CD4+ T Cell Isolation Kit
17952 (Human)
19852 (Mouse)
EasySep™ CD8+ T Cell Isolation Kit
17953 (Human)
19853 (Mouse)
RoboSep™-S
*For fully automated cell separations
Expansion and Activation of Human T Cells
Catalog #
ImmunoCult™-XF T Cell Expansion Medium
Human Recombinant IL-2 (CHO-expressed)
78036 (Human)
ImmunoCult™ Human CD3/CD28 T Cell Activator
10971 (Human)
ImmunoCult™ Human CD3/CD28/CD2 T Cell Activator
Target Antigens for Human T Cell Characterization
Antibody Catalog #
CD3
60127FI (Clone SK7)
60011 (Clone UCHT1)
CD4
60122PE (Clone SK3)
60016 (Clone OKT4)
CD8a
60125PE (Clone RPA-T8)
60022 (Clone SK1)
CD25
60153PE (Clone 2A3)
CD38
60131FI (Clone AT-1)
60014 (Clone HIT2)
CD44
60068 (Clone IM7)
CD45RO
60097 (Clone UCHL1)
HLA-DR
60164 (Clone LN3)
Target Antigens for Mouse T Cell Characterization
Antibody Catalog #
CD3e
60015 (Clone 145-2C11)
CD4
60017 (Clone RM4-5)
60029 (Clone RM4-4)
CD8a
60023 (Clone 53-6.7)
CD25
60010 (Clone 3C7)
60009 (Clone PC61.5)
CD8a
60160 (Clone LG.3A10)

Products for Isolating and Characterizing NK Cells


Isolation of NK Cells
Catalog #
EasySep™ Human NK Cell Isolation Kit
EasySep™ Direct Human NK Cell Isolation Kit
EasySep™ Mouse NK Cell Isolation Kit
Target Antigens for NK Cell Characterization
Antibody Catalog #
CD3
60011 (Clone UCHT1)
CD3e
60015 (Clone 145-2C11)
CD49b
60020 (Clone DX5)
CD56 (NCAM)
60021 (Clone HCD56)

Products for Isolating and Characterizing Dendritic Cells


Isolation of Dendritic Cells
Catalog #
EasySep™ Pan-DC Enrichment Kit
19251 (Human)
19863 (Mouse)
EasySep™ Myeloid DC Enrichment Kit
19061 (Human)
18780 (Mouse CD11c positive selection)
EasySep™ Plasmacytoid DC Enrichment Kit
19062 (Human)
19764 (Mouse)
RoboSep™-S
*For fully automated cell separations
Expansion and Maturation of Human Dendritic Cells
Catalog #
ImmunoCult™ Dendritic Cell Culture Kit
*For differentiation of human monocytes into dendritic cells
ImmunoCult™-ACF Dendritic Cell Medium
*Medium for the culture and differentiation of human monocytes into dendritic cells and their maturation
ImmunoCult™-ACF Dendritic Cell Differentiation Supplement
*Supplement for the differentiation of human monocytes into dendritic cells
ImmunoCult™ Dendritic Cell Maturation Supplement
*Supplement for the maturation of human monocyte-derived dendritic cells
Target Antigens for Human Dendritic Cell Characterization
Antibody Catalog #
CD83
60107 (Clone HB15e)
CD123 (IL-3Rα)
60110 (Clone 6H6)
HLA-DR
60164 (Clone LN3)
Target Antigens for Mouse Dendritic Cell Characterization
Antibody Catalog #
CD11c
60002 (Clone N418)
CD16/CD32
60161 (Clone 2.4
CD43
60042 (Clone R2/60)

Products for Isolating and Characterizing Other Immune Cell Subsets


Target Antigens for Human Immune Cell Characterization
Catalog #
CD3
60127 (Clone SK7)
60011 (Clone UCHT1)
CD14
60124 (Clone MoP9)
CD16
60041 (Clone 3G8)
CD20
60008 (Clone 2H7)
CD24
60134 (Clone 32D12)
CD38
60014 (Clone HIT2)
60131 (Clone AT-1)
CD45
60123 (Clone 2D1)
CD45RO
60097 (Clone UCHL1)
CD56
60021 (Clone HCD56)
CD71
60106 (Clone OKT9)
HLA-DR
60164 (Clone LN3)
Target Antigens for Mouse Immune Cell Characterization
Antibody Catalog #
CD3e
60015 (Clone 145-2C11)
CD11b
60001 (Clone M1/70)
CD19
60112 (Clone 1D3)
60006 (Clone 6D5)
CD24
60099 (Clone M1/69)
CD25
60010 (Clone 3C7)
60009 (Clone PC61.5)
CD27
60160 (Clone LG-3A.10)
CD44
60068 (Clone IM7)
CD45
60030 (Clone 30-F11)
CD45.1
60117 (Clone A20)
CD45.2
60018 (Clone 104)
CD62L
60109 (Clone MEL-14)
CD138 (Syndecan-1)
60035 (Clone 281-2)
Gr-1
60028 (Clone RB6-8C5)
Ly-6G
60031 (Clone 1A8)

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.5 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


Detection and Measurement of Cytokines
Catalog #
Human IFN-gamma ELISA Kit
Human pan IFN-alpha ELISA Kit
Human IL-1 beta ELISA Kit
Human IL-2 ELISA Kit
Human IL-4 ELISA Kit
Human IL-10 ELISA Kit
Human IL-12 (p70) ELISA Kit
Human IL-17A ELISA Kit
Detection and Measurement of Antibodies
Catalog #
Human IgG ELISA Antibody Pair Kit
Human IgM ELISA Antibody Pair Kit
Human IgA ELISA Antibody Pair Kit

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