Expression of activation markers CD23 and CD69 in B-cell non-Hodgkin's lymphoma

CD69 is a Promising Immunotherapy and Prognosis Prediction Target in Cancer

Immunotherapy utilizing T cells that attack tumors is a promising strategy for treatment, but immune suppressive T cell subsets, such as regulatory T cell (Treg), and immune checkpoint molecules, including programmed death-1 (PD-1), can suppress the intensity of a T cell immune reaction and thereby impair tumor clearance. Cluster of differentiation 69 (CD69), known as an early leukocyte activation marker, can be used as a measure or early marker of T cell activation. In recent years, the functions of CD69 in the regulation of Treg/Th17 (T helper cell 17) differentiation and in the tissue retention of T cells have attracted considerable interest. These functions are related to the role of CD69 in immune suppression in tumor environments (TME). In this review, we first summarized current perspectives in the biological function of CD69 and demonstrated that CD69 acts as a regulator of T cell activation, differentiation, retention, and exhaustion. Then, we discussed recent advances in understanding of CD69 deficiency and anti-CD69 antibody administration and shed light on the value of targeting on CD69 for cancer immunotherapy and prognosis prediction.

Identification of recurrent noncoding mutations in B-cell lymphoma using capture Hi-C

The identification of driver mutations is fundamental to understanding oncogenesis. Although genes frequently mutated in B-cell lymphoma have been identified, the search for driver mutations has largely focused on the coding genome. Here we report an analysis of the noncoding genome using whole-genome sequencing data from 117 patients with B-cell lymphoma. Using promoter capture Hi-C data in naive B cells, we define cis-regulatory elements, which represent an enriched subset of the noncoding genome in which to search for driver mutations. Regulatory regions were identified whose mutation significantly alters gene expression, including copy number variation at cis-regulatory elements targeting CD69, IGLL5, and MMP14, and single nucleotide variants in a cis-regulatory element for TPRG1 We also show the commonality of pathways targeted by coding and noncoding mutations, exemplified by MMP14, which regulates Notch signaling, a pathway important in lymphomagenesis and whose expression is associated with patient survival. This study provides an enhanced understanding of lymphomagenesis and describes the advantages of using chromosome conformation capture to decipher noncoding mutations relevant to cancer biology.

TSPAN33 is a novel marker of activated and malignant B cells

We have identified Tspan33 as a gene encoding a transmembrane protein exhibiting a restricted expression pattern including expression in activated B cells. TSPAN33 is a member of the tetraspanin family. TSPAN33 is not expressed in resting B cells, but is strongly induced in primary human B cells following activation. Human 2E2 cells, a Burkitt's lymphoma-derived B cell model of activation and differentiation, also upregulate TSPAN33 upon activation. TSPAN33 is expressed in several lymphomas including Hodgkin's and Diffuse large B cell lymphoma. TSPAN33 is also expressed in some autoimmune diseases where B cells participate in the pathology, including rheumatoid arthritis patients, systemic lupus erythematosus (SLE), and in spleen B cells from MRL/Fas(lpr/lpr) mice (a mouse model of SLE). We conclude that TSPAN33 may be used as a diagnostic biomarker or as a target for therapeutic antibodies for treatment of certain B cell lymphomas or autoimmune diseases.

Differential expression of NF-kappaB target genes in MALT lymphoma with and without chromosome translocation: insights into molecular mechanism

Mucosa-associated lymphoid tissue (MALT) lymphoma is characterized by t(11;18)(q21;q21)/API2-MALT1, t(1;14)(p22;q32)/BCL10-IGH and t(14;18)(q32;q21)/IGH-MALT1, which commonly activate the nuclear factor (NF)-kappaB pathway. Gastric MALT lymphomas harboring such translocations usually do not respond to Helicobacter pylori eradication, while most of those without translocation can be cured by antibiotics. To understand the molecular mechanism of these different MALT lymphoma subgroups, we performed gene expression profiling analysis of 21 MALT lymphomas (13 translocation-positive, 8 translocation-negative). Gene set enrichment analysis (GSEA) of the NF-kappaB target genes and 4394 additional gene sets covering various cellular pathways, biological processes and molecular functions have shown that translocation-positive MALT lymphomas are characterized by an enhanced expression of NF-kappaB target genes, particularly toll like receptor (TLR)6, chemokine, CC motif, receptor (CCR)2, cluster of differentiation (CD)69 and B-cell CLL/lymphoma (BCL)2, while translocation-negative cases were featured by active inflammatory and immune responses, such as interleukin-8, CD86, CD28 and inducible T-cell costimulator (ICOS). Separate analyses of the genes differentially expressed between translocation-positive and -negative cases and measurement of gene ontology term in these differentially expressed genes by hypergeometric test reinforced the above findings by GSEA. Finally, expression of TLR6, in the presence of TLR2, enhanced both API2-MALT1 and BCL10-mediated NF-kappaB activation in vitro. Our findings provide novel insights into the molecular mechanism of MALT lymphomas with and without translocation, potentially explaining their different clinical behaviors.

Identification of genes whose expression patterns differ in benign lymphoid tissue and follicular, mantle cell, and small lymphocytic lymphoma

Improved methods for diagnosing small B-cell lymphomas (SBCLs) and predicting patient response to therapy are likely to result from the ongoing discovery of molecular markers that better define these malignancies. In this report, we identify 120 genes whose expression patterns differed between reactive lymph node tissue and three types of SBCL: follicular lymphoma, mantle cell lymphoma, and chronic lymphocytic leukemia/small lymphocytic lymphoma. Whereas previously published studies have generally analyzed the gene expression profiles of one type of SBCL, work presented in this paper was intended to identify genes that are differentially expressed between three SBCL subtypes. This analysis was performed using mRNA pooled from multiple specimens representing each tissue type. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was used to validate the differential expression of 23 of these genes. Among the 23 validated genes were cyclin D1 (CCND1) and B-cell CLL/lymphoma 2, which have well-known roles in lymphoma pathogenesis. The remaining 21 genes have no currently established role in lymphoma development. Using qRT-PCR, the expression of CCND1 and seven additional genes was further studied in a panel of individual specimens. Genes identified in this study are of biological interest and represent candidate diagnostic markers.

The use of transgenic mice for the production of a human monoclonal antibody specific for human CD69 antigen

The CD69 antigen is the earliest activation marker expressed on leukocyte surfaces after stimulation and it has been correlated with disease state in a variety of inflammatory and autoimmune diseases. We were interested in the generation of a human monoclonal antibody (mAb) against the CD69 antigen. To do this, mice carrying human Ig transgenes (on an inactivated endogenous immunoglobulin H and Igkappa background) were immunized with rat cells transfected with the human CD69 molecule. From over 2000 hybridoma clones generated in different fusions, we were able to obtain a human monoclonal antibody, hAIM-29, which specifically recognizes human CD69 on the surface of activated-human leukocytes. We demonstrate that the antibody is specific for the human CD69 molecule, as shown by double staining with mouse anti-human CD69 antibodies, ELISA, immunoblot and immunoprecipitation studies. Results of additional experiments show that hAIM-29 activates intracellular calcium influx without Ig cross-linking and enhances phorbol myristate acetate-induced cell proliferation in a manner similar to other mouse anti-CD69 antibodies. This report is the first to describe the isolation and characterization of a novel human mAb, hAIM-29, which may have therapeutic potential in diseases associated with the presence of activated cells expressing CD69 antigen.