Investigating the effects of androgen receptor (AR) on the human immune system

Abstract

The human immune system is influenced by factors such as sex hormones, chromosomes, age, infections, and the environment, leading to distinct immune profiles between individuals and between sexes. Females typically mount stronger immune responses, increasing protection against infections but also susceptibility to autoimmune diseases. Testosterone, acting through the androgen receptor (AR), is a key regulator of these sex-based immune differences. AR is expressed in various immune cells, including T cells, B cells, NK cells, dendritic cells (DCs) and monocytes, making peripheral blood mononuclear cells (PBMCs) a suitable model to study its role. While AR is well studied in reproductive cancers, its impact on immune cell behavior remains unclear. In this project, two complementary strategies were applied to investigate AR function, a genetic approach using CRISPR-Cas9 to knock out AR and a pharmacological approach using hormone treatments. In the CRISPR pilot, nucleofection of Cas9-GFP into unstimulated PBMCs showed promising results (up to 50% GFP+, ~70% viability), but delivery of AR-targeting RNPs reduced efficiency. Follow-up experiments testing different programs, time points, and RNP concentrations failed to achieve detectable genome editing (GFP <10%, no sequencing-confirmed knockout), likely due to innate immune sensing of unmodified gRNAs. As an alternative, PBMCs from 10 male donors were treated with dihydrotestosterone (DHT), enzalutamide, or both. Hormone treatments maintained high cell viability (>75%) across all conditions. Although overall immune cell composition remained stable, consistent shifts in the expression of key surface markers were observed. Enzalutamide was associated with reduced activation marker expression on T cells, while testosterone influenced NK cell phenotypes by decreasing CD56 levels. These trends suggest that AR signaling may suppress T cell activation and alter NK cell phenotypes, contributing to sex-based immune variation. Although not statistically significant, the findings highlight AR’s potential to modulate immune function. Future work should focus on optimized CRISPR delivery, broader donor cohorts, and functional assays to clarify how AR shapes immune responses and contributes to sex differences.

Popular Abstract

When Testosterone Talks, Do Immune Cells Listen?

It’s long been known that men and women respond differently to infections and vaccines. Women generally mount stronger immune responses but also face a higher risk of autoimmune diseases. One of the key factors behind these differences is the hormone testosterone, which signals through a protein called the androgen receptor (AR). Interestingly, this receptor is also found on immune cells in our blood, but we still don’t fully understand what it does there. To explore this, we used blood-derived immune cells known as peripheral blood mononuclear cells (PBMCs) as a model to study how AR might influence immune behavior and possibly contribute to immune differences between sexes.

To investigate AR’s role, we first used the powerful gene-editing tool CRISPR-Cas9 to try to "turn off" the AR gene in PBMCs. This approach involved delivering pre-assembled CRISPR molecules into the cells using a technique called nucleofection. While we successfully optimized delivery methods, the actual gene editing didn’t work, the cells seemed to resist editing, likely due to their natural defences against foreign genetic material. This hinted at a deeper complexity in trying to manipulate immune cells genetically.

Since the genetic approach didn’t succeed, we tried a second method, treating the PBMCs with hormone-like drugs that either activate or block the AR. We then measured how the cells responded. The results showed small but consistent changes in certain immune features. Some immune markers, such as HLA-DR and CD56, which are involved in immune activation and natural killer (NK) cell function respectively, were slightly reduced with testosterone-like compounds and slightly increased with AR blockers. These effects were modest but suggests that AR signaling may impact immune activity, particularly in NK and T cells.
Although our findings are preliminary and did not reach strong statistical significance, they offer clues that the androgen receptor may affect certain immune responses. This indicates that sex hormones like testosterone could be shaping how our immune system behaves, even under normal, healthy conditions. Understanding this connection is important not just for basic biology but also for developing treatments that take biological sex into account. Tools like CRISPR hold promise for future personalized therapies, allowing scientists to precisely study or even adjust immune pathways. In parallel, hormonal modulation, using drugs that mimic or block sex hormones, could offer a more accessible way to regulate immune functions based on an individual’s hormonal profile. Altogether, this work adds a small but meaningful piece to the larger puzzle of why men and women experience illness differently, and how we might one day adjust immune treatments to better fit each person.

Master’s Degree Project in Molecular Biology Immunology and Infection Biology, 60 credits, MOBN03, 2025

Department of Biology, Lund University
Supervisor: Camila Consiglio

• author: Kutrolli, Arisa
• supervisor: Camila Consiglio
• organization: Degree Projects in Molecular Biology
• course: MOBN03 20242
• year: 2025
• type: H2 - Master's Degree (Two Years)
• subject: Biology and Life Sciences
• language: English
• id: 9214689
• date added to LUP: 2025-10-30 13:47:02
• date last changed: 2025-10-30 13:47:02