Search results for " monoclonal"
showing 10 items of 807 documents
CD4 monoclonal antibody VIT4 in human alloimmune response in vitro and in vivo.
1996
In the present report the immunosuppressive effects of the murine anti-human CD4 monoclonal antibody (mAb) VIT4 on human alloimmune response in vitro were analyzed. Moreover, the antibody was tested for its activity to prolong allograft survival in seven patients with steroid-refractory allograft rejection. VIT4 inhibited the proliferative response to alloantigens in the mixed lymphocyte reaction (MLR) in a dose-dependent manner. At concentrations of 1 and 10 micrograms/ml VIT4 blocked MLR by 55 +/- 11% and 77 +/- 1%, respectively. Also alloantigen-specific proliferation of in vitro- generated memory T cells was dose-dependently reduced to 23 +/- 1% at a VIT4 concentration of 100 micrograms…
Comparison of allergen-stimulated dendritic cells from atopic and nonatopic donors dissecting their effect on autologous naive and memory T helper ce…
2000
Abstract Background: Because of their production of IL-12, mature dendritic cells (DC) are potent inducers of T H 1 responses. However, recent reports have demonstrated that DCs can also induce T H 2 differentiation. Objective: In the current study we investigated which immune response is induced by DCs in naive CD45RA + or memory CD45R0 + CD4 + T cells from atopic individuals (patients with grass pollen, birch pollen, or house dust mite allergy) compared with nonatopic control subjects. Methods: Immature DCs, generated from peripheral blood monocytes from atopic and nonatopic donors, were pulsed with the respective allergen and fully matured. Then the mature DCs were cocultured in vitro wi…
Molecular Basis for the Interaction of the Hepatitis B Virus Core Antigen with the Surface Immunoglobulin Receptor on Naive B Cells
2001
ABSTRACTThe nucleocapsid of the hepatitis B virus (HBV) is composed of 180 to 240 copies of the HBV core (HBc) protein. HBc antigen (HBcAg) capsids are extremely immunogenic and can activate naive B cells by cross-linking their surface receptors. The molecular basis for the interaction between HBcAg and naive B cells is not known. The functionality of this activation was evidenced in that low concentrations of HBcAg, but not the nonparticulate homologue HBV envelope antigen (HBeAg), could prime naive B cells to produce anti-HBc in vitro with splenocytes from HBcAg- and HBeAg-specific T-cell receptor transgenic mice. The frequency of these HBcAg-binding B cells was estimated by both hybridom…
Antibodies against tumor necrosis factor (TNF) induce T-cell apoptosis in patients with inflammatory bowel diseases via TNF receptor 2 and intestinal…
2011
Background & Aims The anti–tumor necrosis factor (TNF) antibodies infliximab, adalimumab, and certolizumab pegol have proven clinical efficacy in Crohn's disease. Here, we assessed the effects of anti-TNF antibodies on apoptosis in inflammatory bowel disease (IBD). Methods CD14 + macrophages and CD4 + T cells were isolated from peripheral blood and lamina propria mononuclear cells from patients with IBD and control patients. Cell surface markers and apoptosis were assessed by immunohistology and fluorescence-activated cell sorting techniques. Results Lamina propria CD14 + macrophages showed significantly more frequent and higher membrane-bound TNF (mTNF) expression than CD4 + T cells in IBD…
Development of hapten-induced IL-4-producing CD4+ T lymphocytes requires early IL-4 production by alphabeta T lymphocytes carrying invariant V(alpha)…
1998
This paper investigates the mechanisms responsible for the generation of IL-4-producing CD4+ T cells during contact sensitization with the hapten trinitrochlorobenzene (TNCB). Lymph node cells taken 1 day after immunization spontaneously released IL-4 while lymph node cells taken 2 and 3 days after immunization did not produce IL-4. A second wave of IL-4 production that was both antigen-specific and MHC class II (I-A)-restricted was observed 4 days after immunization. The spontaneous release of IL-4 at day 1 was due to the alphabeta+ double-negative (CD4- CD8-) T lymphocytes that also expressed NK1.1 and showed V(alpha)14 rearrangement, while alphabeta+ CD4+ T lymphocytes were the source of…
WHOLE BODY IRRADIATION INDUCES IFN-γ PRODUCTION IN BALB/c MICE BY PREVENTING THE APPEARANCE OF A Vα14+NK T DOWNREGULATORY POPULATION
2000
Lymph node cells from TNCB-immune BALB/c mice fail to produce IFN-gamma when exposed to antigen in vitro. Conversely, lymph node cells of irradiated (550 rads) BALB/c mice produce IFN-gamma. Transfer experiments show that normal BALB/c mice contain cells which suppress IFN-gamma production. These downregulatory cells are CD4(+)alpha beta(+)and rearrange the invariant V alpha 14-J alpha 281 T cell receptor alpha chain, thus belonging to the NK T cell subset. Downregulatory cells probably act by producing IL-4 as their effect is blocked by mAb to IL-4.
Induction of CD4+/CD25+ regulatory T cells by targeting of antigens to immature dendritic cells
2003
AbstractCoupling of ovalbumin (OVA) to anti–DEC-205 monoclonal antibody (mAb) (αDEC) induced the proliferation of OVA-specific T cells in vivo. Expansion was short-lived, caused by dendritic cells (DCs), and rendered T cells anergic thereafter. Phenotypic analysis revealed the induction of CD25+/CTLA-4+ T cells suppressing proliferation and interleukin-2 (IL-2) production of effector CD4+ T cells. The findings were supported by 2 disease models: (1) CD4+ T-cell–mediated hypersensitivity reactions were suppressed by the injection of αDEC-OVA and (2) the application of hapten-coupled αDEC-205 reduced CD8+ T-cell–mediated allergic reactions. Thus, targeting of antigens to immature DCs through …
Opening a Niche for Therapy: Local Lymphodepletion Helps the Immune System to Fight Melanoma
2014
In this issue, Fujiwara et al. report that local ablation of CD4+ T cells in a murine B16 melanoma model, together with concomitant activation of the immune system by OX40L, leads to complete rejection of the melanomas. Rejection was driven mainly by CD8+ T cells, which infiltrated the melanomas and secreted sizeable amounts of IFN-γ. However, CD8+ T-cell infiltration also caused the recruitment of immunosuppressive myeloid-derived suppressor cells (MDSCs). Although these cells did not prevent the rejection of the melanomas, in clinical settings the long-term repopulation of tumors by MDSCs may counteract successful treatment. Thus, local ablation of CD4+ leukocytes may improve anti-melanom…
Selection of distinct Valpha/beta T-cell receptor families during in vivo and in vitro T-cell maturation.
1999
The experimental conditions influencing the use of Valphabeta TCR families were examined in lymph node (LN) cells from peptide-immunized C57BL/6 and Vbeta8.2 transgenic mice. Expanded proportions of Vbeta5, Vbeta8.2, Vbeta9, Vbeta12 and Vbeta14 positive cells and an association of Vbeta8.2 with Valpha11 was found in freshly harvested 8-day or 34-day immune LN cells. In contrast, peptide-specific T-cell lines generated in vitro from 8-day immune lymph node cells were found to be almost exclusively of the Valpha2/Vbeta12 family. However, T-cell lines originating from Vbeta8.2 transgenic mice did not show preferential Valpha usage. Anti-Vbeta8.2 antibody produced different effects: when added …
Inhibition of anti-GD3-ganglioside antibody-induced proliferation of human CD8+ T cells by CD16+ natural killer cells
1994
The ganglioside GD3 has been described as a membrane component of human T cells which is involved in T cell growth. In the present study the activating function of GD3 for human CD4+ and CD8+ T cells was analyzed by five different monoclonal antibodies (mAb) directed against the GD3 molecule. Three mAb U5, Z21 and R24 induced strong proliferation of peripheral blood mononuclear cells and purified CD8+ and CD4+ T cells of normal donors containing less than 5% CD16+ natural killer (NK) cells. In contrast to CD4+ T cells, CD8+ T cells proliferated only weakly in the presence of 15% CD16+ NK cells. The proliferative response of purified CD4+ and CD8+ T cells (< 5% NK cells) correlated with the …