Background Helper-dependent, or gutted, adenoviruses (Ad) lack viral coding sequences, resulting in reduced immunotoxicity compared with conventional Ad vectors. Gutted Ad growth requires a conventional Ad to supply replication and packaging functions in trans. Methods that allow high-titer growth of gutted vectors while reducing helper contamination, and which use safer helper viruses, will fa...

The Qa-1 cell surface phenotype reportedly distinguishes two Ly-1 T cell subsets conjointly required for T helper effector activity. Ly-1 cells, obtained from several different priming regimens, were negatively selected with anti-Qa-1 plus complement and compared with unselected Ly-1 cells for helper cell activity. Priming isolated T cells on antigen-pulsed macrophages in the absence of B cells...

It has recently been shown that hapten-modified cultured Langerhans cells are able to activate small resting syngeneic L3T4+ T helper cells from nonsensitized animals. Repeated stimulation of these T cells with hapten-modified cultured Langerhans cells leads to the establishment of L3T4+ hapten-specific interleukin-4-producing T-cell lines. Here we report on further characteristics of primary h...

Antigen-specific major histocompatibility complex (MHC)-restricted helper T cell precursors were induced to proliferate in cultures of keyhole limpet hemocyanin-primed lymph node cells. Clones of F1 hybrid helper T cells were isolated in limiting-dilution cultures. Each positive culture at a limiting-dilution of lymph node cells gave rise to > 10 helper T cells with a single MHC-restricted spec...

Signal transduction in response to ligand recognition by T cell receptors regulates T cell fate within and beyond the thymus. Herein we examine the involvement of the CD4 molecule in the regulation of T helper cell survival. T helper cells that lack CD4 expression are prone to apoptosis and show diminished survival after adoptive transfer to irradiated recipients. The helper lineage in CD4(-/-)...

A helper cell population with phenotypic characteristics of both B and T cells is described. This helper population, called BH, is present in normal unprimed C57BL/6 mice and preferentially helps the expression of NPb idiotype-bearing plaque-forming B cells in the absence of T helper cells. Its surface phenotype is Lyt-1.2+, Ig+, Lyb-3+, Thy-1.2-, Lyt-2.2-. The helper activity of the BH populat...

Background Interactions between alcohol, infection, and surgery and their effect on differentiation and functionality of T helper cells are not yet completely understood. We hypothesized that alcohol and surgery disturb differentiation of T helper cells and contribute to an impaired immune response. Methods Mice were treated with alcohol for two weeks. Saline treatment served as control. Clin...

Immunocytological properties of the splenic T cell (Tv) which develop into virus plaque-forming cells in response to the antigenic challenge in vitro were investigated in relation to the properties of helper T cells and suppressor T cells in antibody response. Tv was observed in spleen around 1 wk after the intravenous injection of mice with 10(7) sheep erythrocytes. This contrasted with the fi...

background: recurrent miscarriage (rm) affects 2-5% of pregnant women. paternal lymphocyte immunotherapy is a common treatment for rm patients but the outcome has not been consistent. therefore, combined therapy with other immunosuppressive drugs such as 1 a, 25-dihydroxy-vitamin-d3 (vitamin d3) may improve the outcome. objectives: to investigate the effect of vitamin d3 on the balance of two e...

When the IgG1 fraction of anti-idiotypic antibodies raised in guinea pigs is injected into mice, sensitization of idiotypic T and B lymphocytes occurs (1-3). In the present study we analyze the genetic requirements for T-helper cell sensitization by anti-idiotypic antibody. This was done by measuring, in a suitable panel of mouse strains, helper cell responsiveness to two anti-idiotypic reagent...