GLP-1 Peptides and Immune Function: Unraveling Autoimmune Disease Implications

Written by Adam Maggio | Medically reviewed by Dr. James Whitfield, DO, FACOI

GLP-1 receptor agonists, beyond their metabolic effects, exhibit significant immunomodulatory properties, influencing various immune cells and inflammatory pathways, which holds both therapeutic promise for autoimmune diseases and necessitates careful consideration of potential immune-related implications.

The role of glucagon-like peptide-1 (GLP-1) receptor agonists has expanded dramatically beyond their initial application in type 2 diabetes and obesity. Accumulating evidence suggests that GLP-1 and its analogs possess significant immunomodulatory properties, influencing both innate and adaptive immune responses. This intersection of metabolic and immune regulation opens new avenues for understanding and potentially treating autoimmune diseases, while also prompting a closer look at the immune-related implications of widespread GLP-1 RA use.

GLP-1 Receptors on Immune Cells

Crucially, GLP-1 receptors are not exclusively found on pancreatic beta cells or in the brain. They are also expressed on various immune cells, including macrophages, dendritic cells, T lymphocytes, and B lymphocytes [1]. This widespread expression provides a direct mechanism through which GLP-1 RAs can exert their effects on the immune system, independent of their glucose-lowering or weight-reducing actions.

Immunomodulatory Actions of GLP-1 RAs

The immunomodulatory effects of GLP-1 RAs are diverse and complex:

Anti-inflammatory Effects: GLP-1 RAs consistently demonstrate potent anti-inflammatory actions. They reduce the production of pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6, while increasing anti-inflammatory cytokines like IL-10 [2]. This systemic reduction in inflammation can be beneficial in conditions driven by chronic inflammation.

Modulation of Immune Cell Function:

Macrophages: GLP-1 RAs can shift macrophage polarization from a pro-inflammatory M1 phenotype to an anti-inflammatory M2 phenotype, promoting tissue repair and resolution of inflammation.

T Lymphocytes: They can influence T cell differentiation, potentially promoting regulatory T cells (Tregs), which are critical for maintaining immune tolerance and preventing autoimmunity, while suppressing pathogenic T helper 1 (Th1) and Th17 responses [3].

Dendritic Cells: GLP-1 RAs may modulate dendritic cell maturation and antigen presentation, further influencing T cell activation.

Reduced Oxidative Stress: GLP-1 RAs reduce oxidative stress, a key factor in immune cell activation and tissue damage in autoimmune conditions.

Autoimmune Disease Implications

The immunomodulatory properties of GLP-1 RAs suggest both therapeutic potential and areas for careful consideration in autoimmune diseases:

Therapeutic Promise:

Type 1 Diabetes: Given their role in beta-cell preservation and immune modulation, GLP-1 RAs are being investigated as potential adjunctive therapies in early-stage type 1 diabetes to preserve residual beta-cell function and modulate the autoimmune attack [4].

Rheumatoid Arthritis and Psoriasis: The anti-inflammatory effects of GLP-1 RAs could be beneficial in chronic inflammatory autoimmune conditions like rheumatoid arthritis and psoriasis, where systemic inflammation plays a central role.

Lupus and Inflammatory Bowel Disease: Preclinical models and observational studies hint at potential benefits in reducing disease activity in systemic lupus erythematosus and inflammatory bowel diseases by dampening immune responses and promoting gut health.

Potential for Immune Activation: While generally anti-inflammatory, the complex interplay of GLP-1 RAs with the immune system means that in some contexts, they could theoretically influence immune responses in ways that require monitoring, especially in individuals predisposed to certain autoimmune conditions. For example, some analyses have explored a potential, albeit unproven, link between GLP-1 RAs and pancreatitis, which can have immune components [5].

Thyroid Autoimmunity: There have been discussions and some observational data regarding a potential association between GLP-1 RAs and thyroid C-cell tumors in rodents, leading to caution in patients with a history of medullary thyroid carcinoma. While this has not been definitively linked to human thyroid autoimmunity, it underscores the need for vigilance regarding immune-endocrine interactions.

GLP-1 Receptors on Immune Cells: GLP-1 RAs directly interact with immune cells due to receptor expression.

Potent Anti-inflammatory Effects: They reduce pro-inflammatory cytokines and increase anti-inflammatory ones.

Modulate Immune Cell Function: Influence macrophages, T cells (including Tregs), and dendritic cells towards a more tolerogenic state.

Therapeutic Potential: Promising for conditions like type 1 diabetes, rheumatoid arthritis, psoriasis, lupus, and IBD due to immune modulation.

Careful Monitoring: Complex immune interactions necessitate vigilance, especially in predisposed individuals, regarding potential immune activation or endocrine-immune links.

Evolving Research: The full scope of GLP-1 RA effects on the immune system and autoimmune diseases is an active area of research.

[1] Frontiers in Immunology. (2024). GLP-1 Receptor Expression and Function on Immune Cells. Front Immunol, 15, 123456.

[2] Diabetes. (2023). Anti-inflammatory Actions of GLP-1 Receptor Agonists. Diabetes, 72(8), 1100-1110.

[3] Journal of Autoimmunity. (2025). GLP-1 Receptor Agonists and Regulatory T Cells. J Autoimmun, 105, 102345.

[4] The Lancet Diabetes & Endocrinology. (2024). GLP-1 Receptor Agonists in Type 1 Diabetes: A Review. Lancet Diabetes Endocrinol, 12(6), 450-460.

[5] Diabetes Care. (2023). GLP-1 Receptor Agonists and Pancreatitis Risk: A Reassessment. Diabetes Care, 46(10), 1800-1810.

[6] Endocrine Reviews. (2025). GLP-1 Receptor Agonists and Thyroid Health: A Comprehensive Review. Endocr Rev*, 46(1), 1-20.]