We previously reported durable responses in relapsed or refractory (R/R) chronic lymphocytic leukemia (CLL) patients treated with CD19-targeted chimeric antigen receptor-engineered (CD19 CAR) T-cell immunotherapy after ibrutinib failure. Because preclinical studies showed that ibrutinib could improve CAR T cell-antitumor efficacy and reduce cytokine release syndrome (CRS), we conducted a pilot study to evaluate the safety and feasibility of administering ibrutinib concurrently with CD19 CAR T-cell immunotherapy. Nineteen CLL patients were included. The median number of prior therapies was 5, and 17 patients (89%) had high-risk cytogenetics (17p deletion and/or complex karyotype). Ibrutinib was scheduled to begin ≥2 weeks before leukapheresis and continue for ≥3 months after CAR T-cell infusion. CD19 CAR T-cell therapy with concurrent ibrutinib was well tolerated; 13 patients (68%) received ibrutinib as planned without dose reduction. The 4-week overall response rate using 2018 International Workshop on CLL (iwCLL) criteria was 83%, and 61% achieved a minimal residual disease (MRD)-negative marrow response by IGH sequencing. In this subset, the 1-year overall survival and progression-free survival (PFS) probabilities were 86% and 59%, respectively. Compared with CLL patients treated with CAR T cells without ibrutinib, CAR T cells with concurrent ibrutinib were associated with lower CRS severity and lower serum concentrations of CRS-associated cytokines, despite equivalent in vivo CAR T-cell expansion. The 1-year PFS probabilities in all evaluable patients were 38% and 50% after CD19 CAR T-cell therapy, with and without concurrent ibrutinib, respectively (P = .91). CD19 CAR T cells with concurrent ibrutinib for R/R CLL were well tolerated, with low CRS severity, and led to high rates of MRD-negative response by IGH sequencing.

Extracellular matrix (ECM) remodeling is a process that is crucial to the development of embryos, the growth and metastasis of tumors, and wound healing and homeostasis of tissues in adults. As such, it involves dozens of gene products that are regulated by mechanisms operating at transcriptional and multiple posttranslational levels. This complexity of regulation has made the development of a comprehensive understanding of the biology of ECM remodeling in vivo an unusually challenging task, yet such an understanding would be of profound value to our knowledge of and clinical approaches to the treatment of many cancers. The primary effectors of ECM remodeling are the matrix metalloproteinases (MMPs). Homologs of this gene family have been identified in every metazoan examined. We propose that the zebrafish embryo is an ideal system for the study of the regulation of MMP activity, and we present some progress we have made in the development of this organism as a platform for MMP research. We have identified 25 genes encoding MMPs in the zebrafish genome, and 5 genes encoding their endogenous inhibitors, the tissue inhibitors of MMPs. Based on a phylogenetic analysis, we have identified the most probable homologies of these sequences and found that there are two that are of equivocal identity. We have developed 17 antibodies specific to zebrafish MMPs and have begun characterizing the ontogeny of these molecules. Finally, we have developed two novel assays that allow the detection and characterization of active MMPs in vivo (differential in vivo zymography and activity-based protease profiling). In combination with the array of powerful biochemical, genomic, cell, and molecular biological techniques available to zebrafish researchers already, we feel that these new reagents and techniques make the zebrafish the best model system for the study of MMP regulation currently available.

CD72, a 45-kDa type II transmembrane glycoprotein carrying an ITIM motif, is believed to be an inhibitory coreceptor of the BCR. Mature B cells lacking CD72 show enhanced Ca2+ mobilization and are hyperproliferative in response to BCR ligation. However, the signal transduction pathways downstream of BCR signaling that transmit the inhibitory effect of CD72 in mature B cells remain unknown. To address this question, we used hen egg lysozyme-specific BCR transgenic mice to elucidate the differential cell signaling between wild-type and CD72-deficient B cells in response to hen egg lysozyme Ag stimulation. Our results demonstrate that CD72 predominantly down-regulates the major signal transduction pathways downstream of the BCR, including NF-AT, NF-κB, ERK, JNK, p38-MAPK, and PI3K/Akt in mature B cells. CD72 ligation with anti-CD72 Ab (K10.6), which mimics the binding of CD100 (a natural ligand for CD72) to release the inhibitory function of CD72, augments cell proliferation, Ca2+ flux, IκBα activation, and ERK MAPK activity upon Ag stimulation in wild-type B cells. In addition, we show direct evidence that CD72 promotes cell cycle arrest and apoptosis after Ag stimulation in mature B cells. Taken together, our findings conclude that CD72 plays a dominant role as a negative regulator of BCR signaling in primary mature B lymphocytes.

The antiviral efficacy of orally administered adefovir dipivoxil was evaluated in an 18-week study (12 weeks of treatment and 6 weeks of recovery) conducted with woodchucks chronically infected with woodchuck hepatitis virus (WHV). Adefovir dipivoxil is a prodrug of adefovir designed to enhance its oral bioavailability. Following administration of 15 mg of adefovir dipivoxil per kg of body weight in four WHV-infected animals, the mean maximum concentration of adefovir in serum was 0.462 g/ml, with an elimination half-life of 10.2 h, and the oral bioavailability of adefovir was estimated to be 22.9% (؎11.2%). To study antiviral efficacy, the animals were divided into three groups. There were six animals each in a high-dose group (15 mg/kg/day) and a low-dose group (5 mg/kg/day). A vehicle control group consisted of five animals because WHV DNA was detectable only by PCR at the time of the study in one of the original six animals. Efficacy was evaluated by determining the levels of WHV DNA in serum. The geometric mean WHV DNA level for the high-dose group diminished by >40-fold (>1.6 log 10 ) after 2 weeks of treatment and >300-fold (>2.5 log 10 ) at 12 weeks. There was a >10-fold reduction in five of six low-dose animals by 2 weeks, but levels were unchanged in one animal. By 12 weeks of treatment there was a >45-fold (>1.6 log 10 ) reduction of WHV DNA levels, and serum WHV DNA levels were below the limit of quantification in three of six animals. Viral DNA levels returned to pretreatment levels during the 6-week recovery period. There were no clinically significant changes in body weight, hematology, or serum chemistry values, including bicarbonate or lactate, in any of the treated animals. No histologic evidence of liver injury was apparent in the biopsies. Under the conditions of this study, adefovir dipivoxil was an effective antihepadnaviral agent. Chronic hepatitis B virus (HBV) infection is a serious threatto the health and well-being of more than 350 million people, approximately 5% of the world's population, because of the associated risk of significant liver disease, including cirrhosis and hepatocellular carcinoma (15,29). There are few treatment options available for people who are currently infected and therefore would not benefit from the effective vaccine that is available.Current treatment options include two major groups, modifiers of the immune response and inhibitors of viral replication. Alfa interferon is approved for clinical use, but more than two-thirds of patients treated with alfa interferon do not respond (14). Broad application of interferon therapy is limited by a variety of interferon-associated side effects, a treatment regimen that involves repeated parenteral injection, and restriction to patients with compensated liver disease.Effective antiviral chemotherapeutic agents, most often nucleoside analogues, that target hepadnaviral replication are being developed in order to provide suitable treatment for infected individuals (17,18,21,28). Testing drugs in development is facilitate...

CD72 has been reported to regulate BCR‐mediated signals both positively and negatively. SHP‐1 and Grb2 bind, respectively, to ITIM1 and ITIM2 of CD72. We generated transformed B cell lines with an immature phenotype following J2 virus infection of splenocytes from CD72–/– and wild‐type (Wt) mice. The transformed lines were infected with retroviral vectors carrying Tyr (Y) to Phe (F) substitutions in the ITIM sequences (ITIM1 mutated: Y7/F; ITIM2 mutated: Y39/F; and both ITIM mutated: Y7,39/F). Cross‐linking of the BCR induced growth inhibition in transfectants expressing Wt CD72, but this response was less sensitive in transfectants with Y7,39/F. The Y7/F transfectants demonstrated the least sensitive response. We were not able to obtain transfectants with Y39/F, suggesting that CD72 associated with SHP‐1, but not with Grb2, delivers a strong negative signal. Pre‐ligation of CD72, which induces dephosphorylation of the molecule, partially rescued the Wt transfectants from growth inhibition, leading to a growth response profile similar to that of Y7,39/F transfectants. These results suggest that ITIM1/SHP‐1 delivers a very strong negative signal that is down‐modulated by signals through ITIM2/Grb2, leading to delivery of an attenuated negative signal. Thus, pre‐ligation of CD72 results in the manifestation of an ostensible positive signal.