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Hydroxychloroquine reduces T cells activation recall antigen responses
Monika M Kowatsch1, Julie Lajoie1,2, Lucy Mwangi2
1Laboratory of Viral Immunology, Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada.
Hydroxychloroquine (HCQ) significantly reduces T cell activation and cytokine production in healthy individuals. This finding is crucial for understanding immune responses in patients with autoimmune diseases undergoing HCQ treatment, particularly concerning vaccine efficacy.
Area of Science:
- Immunology
- Pharmacology
Background:
- Limited data exists on COVID-19 vaccine response in autoimmune disease patients.
- Immunosuppressants like hydroxychloroquine (HCQ) may impact vaccine response.
Purpose of the Study:
- To assess the impact of HCQ on systemic T cell and humoral immune responses in healthy donors.
- To understand potential implications for vaccine response in patients on HCQ.
Main Methods:
- Healthy donors received daily HCQ for 6 weeks.
- Peripheral blood mononuclear cells (PBMC) and plasma were analyzed using flow cytometry and bead array multiplex assays.
- T cell activation, cytokine levels, and antibody production were measured pre- and post-treatment.
Main Results:
- HCQ decreased ex vivo T cell activation, including specific subsets like CD4+CD161-CCR5+ and CD8+CCR5+.
- A reduction in Th17 and T regulatory cells expressing TIGIT was observed.
- T cells showed diminished responsiveness to activation and cytokine production, with reduced IFNγ and TNFα from memory T cells.
Conclusions:
- HCQ is associated with lower T cell activation and reduced cytokine production.
- These immune changes may affect vaccine response in patients taking HCQ for autoimmune conditions.
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