4-hydroxy-5-nitrophenyl-acetic-acid and Disease-Models--Animal

Caspase-1 is required for nephritis and robust autoantibody development in the pristane model of murine lupus. The objective of this study was to evaluate the immune response and to study the splenic B and T cell populations in wild-type (WT) and caspase-1-/- mice following pristane injection in order to develop an understanding of why absence of caspase-1 is protective in pristane-induced lupus.. Immunization responses to NP-Ficoll and NP-ovalbumin were assessed in WT and caspase-1-/- mice. In vitro IgM and IgG responses to R848 were measured by ELISA. Serum IgM anti-dsDNA and IL-1β were also measured by ELISA. B and T cell populations 2 weeks and 6 months following pristane injection were measured by flow cytometry in WT and caspase-1-/- mice.. Caspase-1-/- mice generate equivalent IgG responses to NP-Ficoll and NP-ova antigens when compared to wild-type mice. Additionally, they secrete IgM and IgG in response to TLR7 activation. Pristane injected WT and caspase-1-/- mice generate robust IgM anti-dsDNA responses. Caspase-1-/- mice have a significant reduction in marginal zone B cell populations compared to WT 6 months after pristane exposure whereas T cell responses are intact in these mice.. Caspase-1-/- mice have intact immune responses but do not develop an expanded marginal zone B cell population in response to pristane-induced lupus. This may be one explanation for reduced IgG autoantibody production in these mice.

Topics: Animals; Antibodies, Antinuclear; B-Lymphocytes; Caspase 1; Cells, Cultured; Disease Models, Animal; Ficoll; Genetic Predisposition to Disease; Imidazoles; Immunization; Immunoglobulin G; Immunoglobulin M; Lupus Erythematosus, Systemic; Mice, Inbred BALB C; Mice, Knockout; Nitrophenols; Ovalbumin; Phenotype; Phenylacetates; Spleen; T-Lymphocytes; Terpenes; Time Factors

Homeostatic B Cell-Attracting chemokine 1 (BCA-1) otherwise known as CXCL13 is constitutively expressed in secondary lymphoid organs by follicular dendritic cells (FDC) and macrophages. It is the only known ligand for the CXCR5 receptor, which is expressed on mature B cells, follicular helper T cells (Tfh), Th17 cells and regulatory T (Treg) cells. Aberrant expression of CXCL13 within ectopic germinal centers has been linked to the development of autoimmune disorders (e.g. Rheumatoid Arthritis, Multiple Sclerosis, Systemic Lupus Erythematosis). We, therefore, hypothesized that antibody-mediated disruption of the CXCL13 signaling pathway would interfere with the formation of ectopic lymphoid follicles in the target organs and inhibit autoimmune disease progression. This work describes pre-clinical development of human anti-CXCL13 antibody MAb 5261 and includes therapeutic efficacy data of its mouse counterpart in murine models of autoimmunity.. We developed a human IgG1 monoclonal antibody, MAb 5261 that specifically binds to human, rodent and primate CXCL13 with an affinity of approximately 5 nM and is capable of neutralizing the activity of CXCL13 from these various species in in vitro functional assays. For in vivo studies we have engineered a chimeric antibody to contain the same human heavy and light chain variable genes along with mouse constant regions. Treatment with this antibody led to a reduction in the number of germinal centers in mice immunized with 4-Hydroxy-3-nitrophenylacetyl hapten conjugated to Keyhole Limpet Hemocyanin (NP-KLH) and, in adoptive transfer studies, interfered with the trafficking of B cells to the B cell areas of mouse spleen. Furthermore, this mouse anti-CXCL13 antibody demonstrated efficacy in a mouse model of Rheumatoid arthritis (Collagen-Induced Arthritis (CIA)) and Th17-mediated murine model of Multiple Sclerosis (passively-induced Experimental Autoimmune Encephalomyelitis (EAE)).. We developed a novel therapeutic antibody targeting CXCL13-mediated signaling pathway for the treatment of autoimmune disorders.

Topics: Animals; Antibodies, Blocking; Arthritis, Experimental; Arthritis, Rheumatoid; B-Lymphocytes; Cell Movement; Cells, Cultured; Chemokine CXCL13; Dendritic Cells, Follicular; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Female; Genetic Engineering; Germinal Center; Hemocyanins; Humans; Immunoglobulin G; Immunotherapy; Macrophages; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred DBA; Multiple Sclerosis; Nitrophenols; Phenylacetates; Receptors, CXCR5; Recombinant Fusion Proteins; Signal Transduction; Th17 Cells