Search results for "CD4 Antigens"
showing 5 items of 45 documents
Altered intracellular sorting signals do not influence the efficacy of genetic melanoma vaccines incorporating helper determinants in mice.
2004
Background A genetic melanoma vaccine consisting of cDNA encoding the model self-antigen tyrosinase-related protein 2 (TRP2) fused in-frame to the immunogenic enhanced green fluorescent protein (EGFP) was able to break immune tolerance and stimulate CD8+ T cells in vivo. In the present study we investigated whether alteration of the intracellular antigen localization as a result of the linkage with immune-enhancing helper proteins affects the resulting immune response. Methods Expression plasmids and recombinant adenoviruses were constructed encoding various fusion proteins with different intracellular sorting signals which direct the antigen to the cytosol, the endoplasmic reticulum or the…
IL-23 receptor regulates unconventional IL-17-producing T cells that control bacterial infections.
2010
AbstractIL-23 plays an important role in autoimmune tissue inflammation and induces the generation of not fully characterized effector cells that mediate protection against pathogens. In this paper, we established the essential role of IL-23R in the host response against intracellular pathogens. IL-23 was critical for the expansion or maintenance of γδ and double negative (DN) αβ T cells. These cells were rapidly recruited to the site of infection and produced large amounts of IL-17, IFN-γ, and TNF-α. Notably, DN T cells transferred into L. monocytogenes-infected RAG2−/− mice prevented bacterial growth, confirming their protective role against intracellular pathogens. Our results show that …
CD4 blockade directly inhibits mouse and human CD4+ T cell functions independent of Foxp3+ Tregs
2013
CD4(+) helper T cells orchestrate protective immunity against pathogens, yet can also induce undesired pathologies including allergies, transplant rejection and autoimmunity. Non-depleting CD4-specific antibodies such as clone YTS177.9 were found to promote long-lasting T cell tolerance in animal models. Thus, CD4 blockade could represent a promising therapeutic approach for human autoimmune diseases. However, the mechanisms underlying anti-CD4-induced tolerance are incompletely resolved. Particularly, multiple immune cells express CD4 including Foxp3(+) regulatory T cells (Tregs) and dendritic cells (DCs), both controlling the activation of CD4(+)Foxp3(-) helper T cells. Utilizing mixed le…
Injection of Donor-Derived OX62+ Splenic Dendritic Cells With Anti-CD4 Monoclonal Antibody Generates CD4+CD25+FOXP3+ Regulatory T Cells That Prolong …
2009
Abstract Objective To examine in a rat model the ability of donor dendritic cells and anti-CD4 monoclonal antibody (mAb) to generate donor-specific CD4+CD25+ regulatory T cells (Tregs) and to evaluate the capacity of these Tregs to prolong skin allograft survival and abrogate the production of donor-specific antibodies after skin grafting. Materials and Methods OX62+ (nonplasmacytoid) splenic dendritic cells were isolated from Fischer rats using magnetic beads and injected (2 × 10 6 ) into Lewis rat recipients with or without treatment with a nondepleting anti-CD4 (W3/25) mAb. After 4 weeks, splenic CD4+CD25+FOXP3+ T cells were harvested using magnetic beads from conditioned animals and inj…
Screening for inhibitors of HIV gp120-CD4 binding using an enzyme-linked immunoabsorbent assay.
1993
Binding of the HIV-1 major viral surface glycoprotein, gp120, to the major cell receptor, CD4, is essential for HIV infection of the target cell and syncytium formation. An enzyme-linked immunoassay using solid phase CD4 was used to quantitate the binding of HIV-1 gp120 to CD4, and to assess the activity and mechanism of action of putative inhibitors of that reaction. Monoclonal antibodies to the gp120 binding site on CD4 (e.g., Leu3a) blocked gp120 binding, while monoclonal antibodies to other portions of CD4 (e.g. OKT4) did not. Both aurintricarboxylic acid and sulfonated polysaccharides (e.g., dextran sulfate) blocked CD4-gp120 interactions by binding to the CD4 component. Human polyclon…