Biology subjects

Fairchild, R. L.

Publications and source records attributed to Fairchild, R. L..

3 recordsLinked to original sources

bioRxiv2023

Spatial Multi-omics of Arterial Regions from Cardiac Allograft Vasculopathy Rejected Grafts

2. AbstractO_ST_ABSBackgroundC_ST_ABSCardiac allograft vasculopathy (CAV) is a major cause of late-graft failure and mortality following heart transplantation. The mechanisms underlying vascular remodeling are poorly understood. A major immune risk factor associated with the development of CAV is the presence of donor-specific antibodies (DSA) that induce chronic endothelial cell (EC) injury, leukocyte recruitment and inflammation resulting in thickening of arterial intima. Here, we molecularly characterized innate and adaptive immune cells present in the arteries of rejected cardiac allografts with DSA and identified protein and transcriptomic signatures distinguishing early and late CAV lesions. MethodsArterial areas of interest (AOIs) from CAV+DSA+ rejected cardiac allografts (N=3; 2 females, 1 male) were subjected to GeoMx digital spatial profiling (DSP). AOIs were scored on the level of CAV progression/neointimal thickening (22 AOIs total; 11 high and 11 low neointima) and were subjected to whole transcriptome and protein profiling. ResultsAOIs with low neointima significantly increased markers for activated inflammatory infiltrates, transcripts of EC activation and gene modules involved in activating metalloproteinases and TP53 regulation of caspases. Inflammatory and apoptotic protein markers significantly correlated with inflammatory modules in AOIs with low neointima. AOIs with high neointima increased TGF{beta}-regulated transcripts and modules enriched for platelet activation/aggregation. Proteins encoding SMCs and growth factors/survival correlated with modules enriched for proliferation/repair in AOIs with high neointima. Key transcripts in promoting proliferation, migration, and EndoMT were significantly associated with increasing neointima scores. ConclusionOur results reveal new protein and transcriptomic signatures associated with CAV progression. Lesions exhibiting inflammatory profiles appear to be early lesions that transition to later proliferative/pro-fibrotic phenotype CAV lesions. These findings should form the foundation for the identification of improved biomarkers to guide CAV treatment.

immunology↗

bioRxiv2022

Sex-specific T cell exhaustion drives differential immune responses in glioblastoma

Sex differences in glioblastoma (GBM) incidence and outcome are well recognized, and emerging evidence suggests that these extend to genetic/epigenetic and cellular differences, including immune responses. However, the mechanisms driving immunological sex differences are not fully understood. Using GBM models, we demonstrate that T cells play a critical role in driving GBM sex differences. Male mice exhibited accelerated tumor growth, with decreased T cell infiltration and increased T cell exhaustion. Furthermore, a higher frequency of progenitor exhausted T cells was found in males, with improved responsiveness to anti-PD1 treatment. Bone marrow chimera and adoptive transfer models indicated that T cell-mediated tumor control was predominantly regulated in a cell-intrinsic manner, which was further corroborated by in vitro exhaustion assays. Moreover, increased T cell exhaustion was observed in male GBM patients. These findings demonstrate sex-specific pre-determined behavior of T cells is critical in inducing sex differences in GBM progression and immunotherapy response. Statement of significanceImmunotherapies in GBM patients have been unsuccessful due to a variety of factors including the highly immunosuppressive tumor microenvironment in GBM. This study demonstrates that sex-specific T cell behaviors are predominantly intrinsically regulated, further suggesting sex-specific approaches can be leveraged to potentially improve therapeutic efficacy of immunotherapy in GBM.

immunology↗

bioRxiv2022

Recipient LAG3 deficiency results in antibody-mediated rejection of mouse renal allografts

Lymphocyte activation gene-3 (LAG3) is a coinhibitory receptor expressed by a range of immune cells. While immunomodulatory potential of LAG3 is being actively explored in cancer and autoimmunity fields, there is no information on how this pathway affects alloreactive immune responses following organ transplantation. The goal of this study was to investigate the functions of recipient LAG3 in a mouse model of renal allograft rejection. We found that mice deficient in LAG3 expression have elevated heterologous immunity against a panel of alloantigens prior to transplantation. Recipient LAG3 deficiency results in rapid rejection of MHC-mismatched renal allografts that are spontaneously accepted by WT recipients, with graft histology characteristic of antibody mediated rejection (ABMR). Depletion of recipient B cells but not CD8+ T cells significantly extended kidney allograft survival in LAG3-/- recipients further supporting ABMR as the main mechanism of graft loss. Treatment of WT recipients with an antagonistic LAG3 antibody enhanced anti-donor immune responses and induced kidney damage associated with chronic rejection. The experiments using conditional LAG3 knockout recipients demonstrated that LAG3 expression on either T or B cells is sufficient to regulate anti-donor humoral immunity. These results are the first to identify LAG3 as a regulator of both T and B cell responses to kidney allografts and a potential therapeutic target for ABMR prevention and treatment.

immunology↗