nitrophenols and Lymphopenia

Exaggerated activation of lymphocytes contributes to the pathogenesis of inflammatory bowel disease (IBD). Medical therapies are linked to the BCL-2 family-mediated apoptosis. Imbalance in BCL-2 family proteins may cause failure in therapeutic responses. We investigated the role of BCL-2 inhibitor ABT-737 for lymphocyte apoptosis in mice under inflammatory conditions. B.6129P2-interleukin (IL)-10(tm1Cgn) /J (IL-10(-/-) ) weighing 25-30 g with ongoing colitis were used. Fifty mg/kg/day ABT-737 was injected intraperitoneally (i.p.). Haematological analyses were performed with an ADVIA 2120 flow cytometer and mass cytometry with a CyTOF 2. Following i.p. administration, ABT-737 was detected in both spontaneous and acute colitis in peripheral blood (PBL) and colon tissue. Treatment led to lymphopenia. CD4(+) CD44(+) CD62L(+) central memory and CD8(+) , CD44(+) CD62L(-) central memory T cells were decreased in PBL upon ABT-737 compared to vehicle-receiving controls. Increased apoptosis upon ABT-737 was determined in blood lymphocytes, splenocytes and Peyer's patches and was accompanied by a decrease in TNF and IL-1B. ABT-737 positively altered the colonic mucosa and ameliorated inflammation, as shown by colonoscopy, histology and colon length. A decreased BIM/BCL-2 ratio or absence of BIM in both Bim(-) (/) (-) and Il10(-) (/) (-) × Bim(-) (/) (-) impeded the protective effect of ABT-737. The BIM/BCL-2 ratio decreased with age and during the course of treatment. Thus, long-term treatment resulted in adapted TNF levels and macroscopic mucosal damage. ABT-737 was efficacious in diminishing lymphocytes and ameliorating colitis in a BIM-dependent manner. Regulation of inappropriate survival of lymphocytes by ABT-737 may provide a therapeutic strategy in IBD.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; Bcl-2-Like Protein 11; Biphenyl Compounds; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Colitis; Dextran Sulfate; Female; Gene Expression; Hyaluronan Receptors; Injections, Intraperitoneal; Interleukin-10; Interleukin-1beta; L-Selectin; Lymphopenia; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Nitrophenols; Piperazines; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; Sulfonamides; Tumor Necrosis Factor-alpha

Therapeutic manipulation of cellular apoptosis holds great promise for malignant and potentially nonmalignant diseases. A relative resistance to apoptosis in RA synovium is associated with increased expression of prosurvival Bcl-2 family members. In this study, we demonstrate that treatment of DBA/1 mice, prior to the onset of CIA with ABT-737, a BH3 mimetic targeting Bcl-2, Bcl-w, and Bcl-x(L), ameliorated disease development. In contrast, treatment of mice with ABT-737 in established CIA did not alter the course of disease. ABT-737 induced lymphopenia, however pathogenic lymphoid populations in CIA mice were less affected, as shown by relatively normal T and B cell responses to CII. Naïve lymphocytes were highly sensitive to apoptosis after culture with ABT-737, but synovial macrophages and neutrophils were not. Mcl-1 was detected in synovial monocyte/macrophages and neutrophils and strikingly, its expression, rather than Bcl-2 and Bcl-x(L), increased in the affected paws and lymphoid organs of mice with CIA. These observations implicate Mcl-1, which is not targeted by ABT-737, in the survival of inflammatory cells in established CIA and suggest that antagonism of Mcl-1 may be more effective in diseases such as RA.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; Arthritis, Experimental; bcl-X Protein; Biphenyl Compounds; Drug Evaluation, Preclinical; Leukocytes; Lymphopenia; Mice; Myeloid Cell Leukemia Sequence 1 Protein; Nitrophenols; Piperazines; Proteins; Proto-Oncogene Proteins c-bcl-2; Sulfonamides; Synovial Membrane

The TNF family cytokine B cell-activating factor belonging to the TNF family (BAFF) (BLyS) plays a fundamental role in regulating peripheral B cell survival and homeostasis. A BAFF-specific receptor (BAFF-R; BR3) appears to mediate these functions via activation of the NF-kappaB2 pathway. Signaling by the BAFF-R is also required to sustain the germinal center (GC) reaction. Engagement of this receptor results in the induction of Bcl-2, suggesting that this antiapoptotic factor acts downstream of the BAFF-R and NF-kappaB2 pathway to promote peripheral B cell survival during primary and Ag-driven development. To test this idea, we created lines of mice coexpressing a Bcl-2 transgene and a signaling-deficient form of the BAFF-R derived from the B lymphopenic A/WySnJ strain. Surprisingly, although dramatically elevated numbers of B cells accumulate in the periphery of these mice, these B cells exhibit extremely perturbed primary development, formation of lymphoid microenvironments, and GC and IgG responses. Moreover, mice expressing the bcl-2 transgene alone display a loss of marginal zone B cells, an expansion of follicular B cells that appear immature, and alterations of the GC reaction. These results suggest that the BAFF-R and Bcl-2 regulate key and nonoverlapping aspects of peripheral B cell survival and development.

Topics: Animals; Apoptosis; B-Cell Activating Factor; B-Cell Activation Factor Receptor; B-Lymphocyte Subsets; Cell Aggregation; Cell Death; Cell Differentiation; Cell Lineage; Chickens; gamma-Globulins; Germinal Center; Immune Sera; Lymphoid Tissue; Lymphopenia; Membrane Proteins; Mice; Mice, Inbred A; Mice, Transgenic; Nitrophenols; Protein Isoforms; Proto-Oncogene Proteins c-bcl-2; Receptors, Tumor Necrosis Factor; Signal Transduction; Spleen; T-Lymphocytes; Tumor Necrosis Factor-alpha

Virgin T cells being primed to Th2-inducing or Th1-inducing Ags, respectively, start to synthesize IL-4 or IFN-gamma as they begin to proliferate. Parallel respective induction of B cells to produce gamma1 or gamma2a switch transcripts provides additional evidence of early divergent Th activity. This report concerns the roles of IL-4, IL-13, and B cells in these early events in vivo. Th2 responses were induced in lymph nodes against hapten-protein given s.c. with killed Bordetella pertussis adjuvant. In T cell proliferation in wild-type mice, IL-4 message up-regulation and gamma1 and epsilon switch transcript production were underway 48-72 h after immunization. The absence of IL-4, IL-13, or B cells did not alter the early T cell proliferative response. The gamma1 and epsilon switch transcript production was still induced in the absence of IL-4, IL-13, or both, but at a reduced level, while the dominance of switching to IgG1 in the extrafollicular hapten-specific plasma cell response was retained. The up-regulation of IL-4 message was not reduced or delayed in the absence of B cells and was only marginally reduced by the absence of IL-13. It is concluded that signals delivered by dendritic cells, which are not dependent on the presence of IL-4, IL-13, or B cells, can prime virgin T cells and induce the early Th2 activities studied. These early events that direct virgin T cells toward Th2 differentiation contrast with the critical later role of Th2 cytokines in selectively expanding Th2 clones and driving further IL-4 synthesis.

Topics: Animals; B-Lymphocytes; Cell Differentiation; Chickens; Epitopes, T-Lymphocyte; gamma-Globulins; Haptens; Immunization; Immunoglobulin Class Switching; Immunoglobulin G; Immunoglobulins; Injections, Subcutaneous; Interleukin-13; Interleukin-4; Lymphocyte Activation; Lymphocyte Cooperation; Lymphopenia; Mice; Mice, Inbred BALB C; Mice, Knockout; Nitrophenols; Phenylacetates; Plasma Cells; RNA, Messenger; Th1 Cells; Th2 Cells; Up-Regulation

Acute disophenol toxicosis, induced in 10 dogs by giving 33, 35, or 40 mg of disophenol/kg of body weight, was treated with the antipyretic dipyrone, lactated Ringer's infusions, or ice baths. Rectal temperature and estimates of hemoglobin concentration, packed cell volume, and total white blood cell count and differential count were recorded. Higher hemogram values were sometimes observed for dogs dying of the toxicosis. Toxicosis was induced in 5 other dogs which were not treated; 1 of these, given the low dose of disophenol, recovered. Two of 3 dogs (67%) treated with the antipyretic recovered, 0 of 2 (0%) given lactated Ringer's infusion recovered, and 2 of 5 dogs (40%) treated with ice baths recovered. One of the surviving dogs treated with antipyretic was given the low disophenol dose and all the other survivors were given the medium disophenol dosage level.

Topics: Animals; Anthelmintics; Dipyrone; Dog Diseases; Dogs; Female; Fever; Hematocrit; Hyperventilation; Ice; Infusions, Parenteral; Injections, Subcutaneous; Leukocytosis; Lymphopenia; Male; Nitrophenols; Vomiting