B-cell chronic lymphocytic leukemia (CLL), the most common leukemia in the US, is an incurable disease of unknown etiology affecting middle-aged and older individuals. Patients with CLL have variable clinical courses: some live for decades without therapy, whereas others succumb in a few years after diagnosis despite treatment. Our data indicate that CLL is a monoclonal disease of autoreactive B cells with receptors for antigen (BCRs) of very restricted structure. BCR structure relates to disease outcome because patients with BCRs without IgVH somatic mutations (U-CLL) have a much more aggressive course than patients with BCRs with somatic mutations (M-CLL). The principles governing the biology of CLL cells are similar to those of systemic autoimmunity. Autoantigens cull susceptible B cells out of the normal repertoire and into the disease process;this autoantigen selection is probably aided by intermittent stimulation by microbes. Autoantigenic drive does not appear to stop at leukemic transformation, and we believe this factor is the most important in determining the fate of CLL cells and also of the patient. For these reasons, defining the specific immunoreactive epitopes of the autoantigens that drive the leukemic process is critical. In our studies we will focus on autoantigens that emerge during cellular apoptosis;these autoantigens can be of native structure or chemically modified during the apoptotic process. The autoantigenic epitopes as well as mimetic epitopes from phage-display libraries will be delineated, key residues involved in epitope-BCR affinity scrutinized, and then altered to obtain variants with greater or lesser binding constants (Aim 1). Because the consequences of autoantigen binding determine leukemic cell fate, it is pivotal to determine these and establish the parameters that decide cell fate. CLL cells will be stimulated with surrogate antigens and native or mimetic epitopes that vary in form (soluble vs. insoluble), valency (monomeric vs. multimeric), and affinity (low, intermediate, and high) for the BCR. Initials studies will focus on the mechanisms whereby low-affinity BCR engagement leads to CLL cell apoptosis (Aim 2). Since in vivo B lymphocytes receive signals from several sources and through multiple pathways, we will look for synergy or antagonism between BCR-mediated signals and those delivered through intracellular Toll- like receptor 9 (Aim 3). The results of these studies will provide a structural and mechanistic understanding of the relevant autoantigens in this disease and how these autoantigens stimulate CLL cells, ultimately impacting on patient survival. They will lay the groundwork for future pre-clinical studies targeting the BCRs and the antigens bound in this incurable disease.

Public Health Relevance

B-cell chronic lymphocytic leukemia is a common, incurable disease, affecting middle-aged and older individuals when they could be enjoying the fruits of their working years. The results of our studies will provide an understanding of how this type of leukemia cell is stimulated to grow. The studies lay the groundwork for future therapies which will target the stimulants or the molecules on the leukemia cells that the stimulants bind.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
4R01CA081554-08
Application #
8193169
Study Section
Hypersensitivity, Autoimmune, and Immune-mediated Diseases Study Section (HAI)
Program Officer
Howcroft, Thomas K
Project Start
2000-01-01
Project End
2013-05-31
Budget Start
2011-06-01
Budget End
2012-05-31
Support Year
8
Fiscal Year
2011
Total Cost
$311,150
Indirect Cost
Name
Feinstein Institute for Medical Research
Department
Type
DUNS #
110565913
City
Manhasset
State
NY
Country
United States
Zip Code
11030
Gupta, Rashmi; Yan, Xiao J; Barrientos, Jacqueline et al. (2018) Mechanistic Insights into CpG DNA and IL-15 Synergy in Promoting B Cell Chronic Lymphocytic Leukemia Clonal Expansion. J Immunol 201:1570-1585
Minici, Claudia; Gounari, Maria; Übelhart, Rudolf et al. (2017) Distinct homotypic B-cell receptor interactions shape the outcome of chronic lymphocytic leukaemia. Nat Commun 8:15746
Herndon, Thomas M; Chen, Shih-Shih; Saba, Nakhle S et al. (2017) Direct in vivo evidence for increased proliferation of CLL cells in lymph nodes compared to bone marrow and peripheral blood. Leukemia 31:1340-1347
Bosch, Rosa; Mora, Alba; Vicente, Eva Puy et al. (2017) Fc?RIIb expression in early stage chronic lymphocytic leukemia. Leuk Lymphoma 58:2642-2648
Patten, Piers E M; Ferrer, Gerardo; Chen, Shih-Shih et al. (2016) Chronic lymphocytic leukemia cells diversify and differentiate in vivo via a nonclassical Th1-dependent, Bcl-6-deficient process. JCI Insight 1:
Chen, S-S; Chang, B Y; Chang, S et al. (2016) BTK inhibition results in impaired CXCR4 chemokine receptor surface expression, signaling and function in chronic lymphocytic leukemia. Leukemia 30:833-43
Guo, Benchang; Zhang, Lu; Chiorazzi, Nicholas et al. (2016) IL-4 rescues surface IgM expression in chronic lymphocytic leukemia. Blood 128:553-62
Cui, X; Zhang, L; Magli, A R et al. (2016) Cytoplasmic myosin-exposed apoptotic cells appear with caspase-3 activation and enhance CLL cell viability. Leukemia 30:74-85
Sarkar, Mohosin; Liu, Yun; Qi, Junpeng et al. (2016) Targeting Stereotyped B Cell Receptors from Chronic Lymphocytic Leukemia Patients with Synthetic Antigen Surrogates. J Biol Chem 291:7558-70
Wang, Jie; Sevier, Carolyn S (2016) Formation and Reversibility of BiP Protein Cysteine Oxidation Facilitate Cell Survival during and post Oxidative Stress. J Biol Chem 291:7541-57

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