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Most memory T cells reside in mucosal and lymphoid organs as tissue resident memory T cells (TRM). During acute cellular rejection after lung transplantation, recipient-derived T cells recruited to the lung persist as long-lived TRM. Studies in cutaneous skin cancer suggest that systemic lymphodepletive therapies, like alemtuzumab, spare skin TRM. We aimed to determine the impact of alemtuzumab on lung TRM survival by comparing donor TRM persistence between lung transplant recipients receiving alemtuzumab versus basiliximab induction immunosuppression. A convenience cohort was identified of adult lung transplant recipients who had cryopreserved bronchoalveolar lavage (BAL) cells obtained between 0.5 to 2.8 months post-transplantation. Multiparameter spectral flow cytometry was used to phenotype T cells; donor versus recipient origin was determined by staining for unique human leukocyte antigen expression. To estimate total lung CD3+ T cell content, we stained simultaneously obtained transbronchial biopsies for CD3 using immunohistochemistry. Unpaired Mann Whitney U test was used to identify statistically significant differences in T cell phenotype and content in lungs after induction with alemtuzumab or basiliximab. We included BAL from 25 lung transplant recipients (15 alemtuzumab, 10 basiliximab); transbronchial biopsies were available for 12. Median age was 56 for alemtuzumab and 39 for basiliximab; interstitial lung disease was the primary indication in the alemtuzumab cohort versus cystic fibrosis in the basiliximab cohort. There was a M:F ratio of 3:2 for both cohorts. We found no difference in the proportion of persisting donor CD8+ or CD4+ T cells in the BAL based on induction immunosuppression (Figure, p = 0.99 for CD8, p = 0.28 for CD4). We also found no difference in the persistence of donor regulatory T cells (CD127loCD25hiFOXP3+). The percentage of CD3+ cells found on IHC ranged from 3 - 7% in all biopsies. There was a trend towards increased total T cell content of the lungs of those study participants who underwent induction with basiliximab (p = 0.1). Systemic lymphodepletive therapy with alemtuzumab spares TRM after lung transplantation, but a trend towards increased T cell content in the lungs of those who received basiliximab. This data suggests that systemic therapies may not adequately target potentially harmful TRM. [ABSTRACT FROM AUTHOR]