IL21R Antibody

What is IL21R and what is its significance in immunological research?

IL21R (also known as CD360, IMD56, NILR, or novel interleukin receptor) is a receptor for interleukin-21 with a molecular weight of approximately 59.1 kilodaltons. The protein is encoded by the IL21R gene in humans and has orthologs in several species including canines, porcines, monkeys, mice, and rats .

IL21R is significant in immunological research because it mediates the signaling pathway that controls various immune responses, particularly in B cell differentiation and antibody production. IL21R signaling is also crucial in CD8 T cell differentiation and function, especially in conditions of chronic antigen presentation such as persistent infections, cancer, and autoimmune diseases . The receptor's involvement in multiple immune pathways makes it a key target for understanding immune regulation and developing therapeutic strategies.

What are the common applications of IL21R antibodies in research?

IL21R antibodies are utilized in multiple research applications, with the most common being:

Researchers should select antibodies validated specifically for their intended application and experimental system to ensure reliable results.

How does IL21R signaling influence T cell and B cell functions in disease contexts?

IL21R signaling plays distinct but interconnected roles in T and B cell functions in different disease contexts:

B Cell Functions:

• IL21R signaling in B cells leads to the generation of high-affinity, class-switched antibodies

• This pathway is critical for germinal center formation and plasma cell differentiation

• In autoimmune conditions, dysregulated IL21R signaling contributes to autoantibody production

T Cell Functions:

• CD4 T cells are the primary producers of IL-21, which signals through IL21R on CD8 T cells

• In chronic infections and cancer, IL-21:IL21R signaling promotes CD8 T cell effector functions and memory differentiation

• IL21R signaling helps prevent terminal exhaustion of CD8 T cells in chronic antigen presentation conditions

• The pathway influences CD8 T cell metabolism, which affects their longevity and function in tissues

In autoimmune diseases, CD8 T cells expressing IL21R may contribute to disease pathogenesis through autoreactive mechanisms, making this pathway a potential therapeutic target. The specific influence varies by disease, with different autoimmune conditions showing distinct patterns of IL-21 production and IL21R expression .

What are the optimal experimental conditions for detecting IL21R using antibodies?

Optimal experimental conditions vary by application, but several key considerations apply across methods:

For Western Blot:

• Antibody concentrations: Studies show optimal results at 1-2 μg/mL for human samples using polyclonal antibodies

• Sample preparation: Proper cell lysis and protein denaturation are critical

• Expected band size: Approximately 59 kDa for human IL21R

• Positive controls: HepG2 cell lysates have been validated for human IL21R detection

For Flow Cytometry:

• Fresh vs. fixed cells: PE-conjugated anti-IL21R antibodies (e.g., clone #152512) work well with fresh cells

• Buffer optimization: PBS with 1-2% BSA improves signal-to-noise ratio

• Cell types: B lymphoma cell lines (e.g., A20 mouse B cell lymphoma) serve as positive controls for mouse IL21R

• Titration: Determine optimal antibody concentration through serial dilutions

For Immunofluorescence:

• Fixation methods: 4% paraformaldehyde typically preserves IL21R epitopes

• Antibody concentration: 20 μg/mL has been validated for A431 cells

• Antigen retrieval: May be necessary for tissue sections, but can be cell-line dependent

Researchers should always perform validation steps, including appropriate positive and negative controls, to confirm specificity before proceeding with experiments.

How can IL21R antibodies be used to investigate autoimmune disease mechanisms?

IL21R antibodies serve as powerful tools for investigating autoimmune disease mechanisms through multiple approaches:

Cellular Expression Profiling:

• Flow cytometric analysis to identify IL21R-expressing immune cell populations in patient samples

• Comparative analysis of IL21R expression levels between healthy controls and autoimmune patients

• Correlation of expression with disease activity scores or clinical parameters

Mechanistic Studies:

• Co-localization studies using IL21R antibodies alongside other markers to identify cellular interactions

• Analysis of downstream signaling pathways activated by IL21R in different immune cell subsets

• Investigation of IL21R+ CD8 T cell function in autoimmune pathogenesis through in vitro stimulation assays

Tissue-Specific Analyses:

• Immunohistochemistry or immunofluorescence of affected tissues (e.g., skin in psoriasis, synovium in rheumatoid arthritis)

• Quantification of IL21R+ cells in tissue infiltrates and correlation with tissue damage

• Assessment of tissue-resident memory T cells expressing IL21R

For example, in systemic lupus erythematosus (SLE), researchers have used IL21R antibodies to investigate whether IL21R signaling in CD8 T cells confers disease protection, as suggested by graft-versus-host disease models . Similarly, in psoriasis research, IL21R antibodies have been used to study skin-recruited CD4+ cells driving IFN-γ-dependent epidermal hyperplasia .

What approaches should researchers use to validate IL21R antibody specificity?

Thorough validation of IL21R antibody specificity is essential for reliable research outcomes. Key validation approaches include:

Genetic Controls:

• Testing on IL21R knockout or knockdown models

• Comparison with IL21R overexpression systems

• Use of cells from IL21R gene polymorphism carriers

Multiple Detection Methods:

• Confirm findings across different application methods (e.g., WB, flow cytometry, IHC)

• Use antibodies targeting different epitopes of IL21R

• Compare results from polyclonal and monoclonal antibodies

Blocking Experiments:

• Pre-incubation with immunizing peptide to block specific binding

• Competitive binding with unlabeled antibody

• Dose-dependent blocking studies

Cross-Reactivity Assessment:

• Testing on cells/tissues known to be negative for IL21R

• Comparing reactivity across species with known sequence homology

• Evaluating binding to related receptors in the same family

Antibody Performance Table:

How does IL21R signaling differ between chronic infections, cancer, and autoimmune conditions?

IL21R signaling exhibits context-specific functions across different disease states, which can be studied using IL21R antibodies:

In Chronic Viral Infections:

• IL21R signaling maintains CD8 T cell effector function while preventing terminal exhaustion

• Studies using models such as LCMV clone 13, Toxoplasma gondii, and mouse polyomavirus demonstrate that IL21R signaling helps CD8 T cells balance tissue damage with pathogen control

• IL21R signaling affects CD8 T cell metabolism to maintain longevity in tissues under chronic antigen stimulation

In Cancer:

• IL21R functions as an oncogenic factor in certain cancers like gastric cancer, where it's regulated by the lncRNA MALAT1/miR-125a-3p axis

• IL21R signaling can promote anti-tumor immune responses by enhancing CD8 T cell function

• A fusion protein of anti-PD-1 antibody to IL-21 shows enhanced CD8 T cell responses with memory stem cell characteristics

In Autoimmune Diseases:

• Elevated IL-21 production, increased IL21R expression, and polymorphisms in either gene are documented in multiple autoimmune conditions

• In SLE, IL21R signaling primarily affects CD4 T cell-to-B cell interactions, driving autoantibody production

• In contrast to its protective role in chronic infections, IL21R signaling in CD8 T cells may drive autoimmune pathogenesis in certain conditions

Researchers can use IL21R antibodies to delineate these context-specific functions through comparative studies of receptor expression, signaling pathway activation, and functional outcomes in different disease models.

What role does IL21R play in CD8 T cell exhaustion and how can researchers study this phenomenon?

IL21R plays a critical role in preventing CD8 T cell exhaustion during chronic antigen exposure. Researchers can employ several strategies to study this phenomenon:

Experimental Approaches:

• Expression Analysis: Using IL21R antibodies to track receptor expression during progressive exhaustion states

• Functional Assays: Measuring cytokine production, cytotoxicity, and proliferation of IL21R+ vs. IL21R- CD8 T cells

• Metabolic Profiling: Assessing how IL21R signaling alters T cell metabolism to prevent terminal exhaustion

• Transcriptional Analysis: Examining how IL21R signaling affects exhaustion-associated gene signatures

Key Research Findings:

• IL-21 produced by CD4 T cells signals through IL21R on CD8 T cells to maintain their effector functions during chronic infections and cancer

• IL21R signaling prevents terminal exhaustion in CD8 T cells, partially through effects on cellular metabolism

• Recent work using a fusion protein of anti-PD-1 antibody to IL-21 demonstrates that combined stimulation of IL21R with PD-1 blockade generates CD8 T cells with enhanced memory stem cell characteristics and proliferation potential

Research Methodology Table:

What are the implications of IL21R polymorphisms in autoimmune disease research?

IL21R polymorphisms have significant implications for autoimmune disease research, providing insights into disease susceptibility, progression, and treatment response:

Research Findings:

• Polymorphisms in IL21R are correlated with the development of systemic lupus erythematosus (SLE)

• Genetic variations in IL21R can affect receptor expression levels, binding affinity, or downstream signaling pathways

• The functional consequences of these polymorphisms often depend on the specific autoimmune disease context

Research Approaches Using IL21R Antibodies:

• Expression Analysis: Comparing IL21R protein expression levels between individuals with different polymorphisms

• Functional Studies: Assessing how polymorphisms affect IL21R signaling and downstream functional outcomes

• Cell-Type Specific Effects: Determining whether polymorphisms differentially impact IL21R function in B cells versus CD8 T cells

• Therapeutic Implications: Evaluating whether polymorphisms predict response to therapies targeting the IL-21/IL21R pathway

For example, in SLE research, IL21R antibodies can be used to investigate how polymorphisms in the IL21R gene affect the CD4 T cell-to-B cell interactions that drive disease pathogenesis . Additionally, researchers can examine whether these polymorphisms influence IL21R expression on CD8 T cells and whether this correlates with disease protection, as suggested by graft-versus-host disease models .

How can IL21R antibodies contribute to cancer immunotherapy research?

IL21R antibodies offer multiple avenues for advancing cancer immunotherapy research:

Investigation of IL21R as a Therapeutic Target:

• Characterization of IL21R expression on tumor-infiltrating lymphocytes using immunohistochemistry and flow cytometry

• Analysis of IL21R signaling in promoting anti-tumor CD8 T cell responses

• Evaluation of IL21R as a biomarker for immunotherapy response prediction

Development of Novel Therapeutic Approaches:

• Testing of IL21R agonists to enhance CD8 T cell function in the tumor microenvironment

• Investigation of IL21/IL21R pathway stimulation in combination with immune checkpoint blockade

• Exploration of IL21R-targeted antibody-drug conjugates for cancers overexpressing IL21R

Mechanistic Studies:

• Analysis of how IL21R signaling affects memory stem cell characteristics in tumor-specific T cells

• Investigation of metabolic programming induced by IL21R signaling in tumor-reactive CD8 T cells

• Evaluation of IL21R's role in preventing T cell exhaustion in the tumor microenvironment

Recent findings demonstrate that IL21R functions as an oncogenic factor in gastric cancer and is regulated by the lncRNA MALAT1/miR-125a-3p axis . Additionally, research using a fusion protein of anti-PD-1 antibody to IL-21 shows promise in generating CD8 T cells with enhanced memory stem cell characteristics and proliferation potential , highlighting the potential for synergistic effects when combining IL21R stimulation with checkpoint inhibition.

What are the key considerations for studying IL21R in different animal models of autoimmune diseases?

When studying IL21R in animal models of autoimmune diseases, researchers should consider several important factors:

Species-Specific Considerations:

• Sequence homology of IL21R between humans and the model species (canine, porcine, monkey, mouse, rat)

• Potential functional differences in IL21R signaling across species

• Availability of species-specific IL21R antibodies validated for various applications

Model Selection Factors:

• Relevance of the model to human disease pathophysiology

• Expression patterns of IL21R in the target tissues of interest

• Whether IL21R signaling is implicated in the specific autoimmune disease being modeled

Methodological Approaches:

• Flow cytometric analysis of IL21R expression on immune cell subsets during disease progression

• Immunohistochemistry to localize IL21R+ cells in affected tissues

• Genetic manipulation (knockout, knockin, or conditional deletion) of IL21R to assess functional relevance

Validated Animal Models for IL21R Research:

• Graft-versus-host disease models of murine lupus for studying IL21R in SLE

• Experimental autoimmune encephalomyelitis for multiple sclerosis research

• Collagen-induced arthritis for rheumatoid arthritis studies

• NOD mice for type 1 diabetes research

When using mouse models, researchers should note the availability of specific tools like the Goat Anti-Mouse IL-21R Antigen Affinity-purified Polyclonal Antibody, which has been validated for flow cytometry in mouse B cell lymphoma cell lines .