Novel chemokine-peptide-MHC II CAR-T cell treatment alleviates inflammation in chronic beryllium disease 2309489

Abstract Introduction In chronic beryllium disease (CBD), elevated levels of the inflammatory chemokines CCL3 and CCL4 in the lungs coincide with expanded populations of CD4+ T cells specific to beryllium (Be)-modified peptides derived from these chemokines. Here, we generated HLA-DP2 transgenic (Tg) CCL3-deficient mice (CCL3-/-) that also lack CCL4 to investigate their role in disease development. Methods Mice strains: HLA-DP2 Tg WT, FVB-N, CCL3, and TNF-α. Mice were intratracheally administered with BeO (100µg) on days 0,1, and 2 and euthanized at day 12 or boosted at days,14,15,18,19, and euthanized on day 21. BAL fluid (BALF) was obtained from the instillation of 1 ml PBS. BeO-exposed WT HLA-DP2 Tg (CD45.2) mice were injected intravenously with DR-a or CCL4-CAR- T cells on day 8. Flow cytometry, q-PCR, IFN-γ and IL-2 ELISPOT, Histology (H&E), Tetramer staining, RNA-sequencing, and CAR-T cell design and preparation. Results Be-exposed CCL3-/- mice maintained normal numbers of lung macrophages and dendritic cells (DCs) but exhibited significantly reduced total and HLA-DP2-CCL/Be tetramer-specific CD4+ T cells, IFN-γ-producing CD4+ T cells, and peribronchovascular aggregates, consistent with attenuated inflammation. CCL3 was predominantly expressed in macrophages and DCs, and bone marrow chimera studies confirmed that hematopoietic-derived DCs are the key regulators of CCL/Be-specific CD4+ T cell responses. RNA sequencing of lung-resident CCL4/Be tetramer-positive CD4+ T cells revealed a transcriptional profile enriched for inflammatory and cholesterol metabolism pathways, with elevated IFN-γ, TNF-α, and IL-17a gene expression. Moreover, Be-exposed HLA-DP2 Tg mice lacking TNF-α or treated with peptide-MHC II CAR-T cells targeting CCL4/Be-specific CD4+ T cells showed reduced T cell responses. Conclusion These findings demonstrate that CCL3 and CCL4 promote CCL/Be-specific CD4+ T cell responses and highlight peptide-MHC II CAR-T cells as a novel strategy for depleting self-peptide/Be-specific CD4+ T cells in CBD. Funding Source NIH R01 HL152756 Topic Categories Immune Mechanisms of Human Disease (HUM)