The Miklos Lab
The Miklos laboratory focuses on B cell reconstitution after allogeneic hematopoietic cell transplantation and the serologic identification of minor histocompatibility antigens. Allogeneic hematopoietic cell transplantation (HCT) offers the possibility of cure for many patients with hematologic diseases through beneficial allogeneic immune responses against the tumor called graft versus tumor (GVT). However the full potential of allo-HCT has not been realized because of transplant related complications, especially graft versus host disease (GVHD). When patients and donors are MHC-identical, disparities in minor histocompatibility antigens (mHA) contribute substantially to GVHD. It is therefore likely that a more extensive characterization of mHA will identify critical disease-specific GVT alloimunity to be augmented and GVHD responses to be avoided.
- Male HCT patients with female donors develop high titer H-Y antigen specific antibody responses 4-12 months after sex-mismatched transplantation in association with chronic GVHD. H-Y antibody development involves the coordinated recognition of mHA by donor B cells as well as T cells. The association of allogeneic Antibody development and chronic GVHD suggested B cell targeted therapies may be effective against chronic GVHD. Multiple phase II trials using rituximab therapy (anti-CD20 monoclonal antibody) have confirmed an important B cell role in chronic GVHD with overall rituximab response rates ranging 40-70% rate in steroid refractory cGVHD patients. Stanford has just completed a 35 patient phase II trial of prophylactic rituximab infused two months after allogeneic HCT resulting in a promisingly low cGVHD incidence of 20% while maintaining strong graft versus leukemia benefit in patients with Chronic Lymphocytic Leukemia and Mantle Cell Lymphoma. A third ongoing phase II trial incorporates rituximab along with prednisone in the initial treatment of new onset chronic GVHD.
- Human B cell reconstitution following allogeneic HCT is being characterized by fluorescent immunophenotyping patient bone marrow and peripheral blood samples with rituximab interventions to elucidate important alloreactive B cell developmental stages.
- In collaboration with Dr. Andrew Fire, the Miklos lab is “deep sequencing” immunoglobulin heavy chain Immunoglogulin genes using 4-5-4 DNA sequencing technology yielding thousands of B cell clonal sequences enabling: 1) B cell malignancy disease quantification before and after HCT, 2) detailed B cell reconstitution kinetics and donor/recipient contribution, and 3) clonal analysis of antigen specific responses following allo-HCT responses.
- In an effort to discover the clinically relevant graft versus tumor (GVT) and graft versus host disease (GVHD) mHA, Dr. Miklos has pioneered protein microarray technology employing both custom printed H-Y antigen arrays and commercially available ProtoArray microarrays that display 8000 recombinant human proteins to serologically screen for mHA targets of new Antibody responses one year after allo-HCT that were not present in the pre or donor sera. In order to distinguish persistent recipient antibody response from newly developing donor antibodies, they have also developed allotyping reagents/assays.
The overall goal of David Miklos’ research is a complete characterization of B cell allogeneic immune response after HCT, characterizing B and T cell coordinated mHA immune responses, and defining the role of novel mHA in the development of GVHD and prevention of disease relapse.