Heightened TLR7 signaling primes BCR-activated B cells in chronic graft-versus-host disease for effector functions.

Chronic graft-versus-host disease (cGVHD) is a debilitating, autoimmune-like syndrome that can occur after allogeneic hematopoietic stem cell transplantation. Constitutively activated B cells contribute to ongoing alloreactivity and autoreactivity in patients with cGVHD. Excessive tissue damage that occurs after transplantation exposes B cells to nucleic acids in the extracellular environment.

Single-cell landscape analysis unravels molecular programming of the human B cell compartment in chronic GVHD.

Alloreactivity can drive autoimmune syndromes. After allogeneic hematopoietic stem cell transplantation (allo-HCT), chronic graft-versus-host disease (cGVHD), a B cell-associated autoimmune-like syndrome, commonly occurs. Because donor-derived B cells continually develop under selective pressure from host alloantigens, aberrant B cell receptor (BCR) activation and IgG production can emerge and contribute to cGVHD pathobiology.

A Phase I Trial of SYK Inhibition with Fostamatinib in the Prevention and Treatment of Chronic Graft-Versus-Host Disease.

Despite the exciting advancement of novel therapies, chronic graft-versus-host disease (cGVHD) remains the most common cause of non-relapse mortality after allogeneic hematopoietic stem cell transplantation (HCT). Frontline treatment of cGVHD involves systemic steroids, which are associated with significant morbidities. We previously found that inhibition of spleen tyrosine kinase (SYK) with fostamatinib preferentially eradicated aberrantly activated B cells in both ex vivo studies of cGVHD patient B cells, as well as in vivo mouse studies.

Alphavirus Replicon Particle Vaccine Breaks B Cell Tolerance and Rapidly Induces IgG to Murine Hematolymphoid Tumor Associated Antigens.

immune responses to myeloid and other blood-borne tumors are notably limited and ineffective, making our ability to promote immune responses with vaccines a major challenge. While focus has been largely on cytotoxic cell-mediated tumor eradication, B-cells and the antibodies they produce also have roles in anti-tumor responses. Indeed, therapeutic antibody-mediated tumor cell killing is routinely employed in patients with hematolymphoid cancers, but whether endogenous antibody responses can be incited to blood-born tumors remains poorly studied.

BAFF promotes heightened BCR responsiveness and manifestations of chronic GVHD after allogeneic stem cell transplantation.

Patients with chronic graft-versus-host disease (cGVHD) have increased B cell-activating factor (BAFF) levels, but whether BAFF promotes disease after allogeneic bone marrow transplantation (allo-BMT) remains unknown. In a major histocompatibility complex-mismatched model with cGVHD-like manifestations, we first examined B-lymphopenic μMT allo-BMT recipients and found that increased BAFF levels in cGVHD mice were not merely a reflection of B-cell number. Mice that later developed cGVHD had significantly increased numbers of recipient fibroblastic reticular cells with higher BAFF transcript levels.