Concanavalin A stimulation of T-cell cytotoxicity has been shown to be absolutely dependent on helper T-cell collaboration. Thymocytes stimulated with ConA do not differentiate to yield cytotoxic effector cells. However, thymocytes cocultured with irradiated spleen cells as helpers and ConA yield high levels of cytotoxicity. The helper cell bears theta antigens on its surface, is not an adheren...

Two types of T helper (Th) cells have been defined on the basis of their cytokine secretion patterns. The decision of a naive T cell to differentiate into Th1 or Th2 is crucial, since to a first approximation it determines whether a cell-mediated or humoral immune response is triggered against a particular pathogen, which profoundly influences disease outcome. Here we show that the internal beh...

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...

T follicular helper (Tfh) cells are the subset of CD4 T helper cells that are required for generation and maintenance of germinal center reactions and the generation of long-lived humoral immunity. This specialized T helper subset provides help to cognate B cells via their expression of CD40 ligand, IL-21, IL-4, and other molecules. Tfh cells are characterized by their expression of the chemoki...

Anaphylaxis caused by allergen sensitization and vaccination is a serious health concern. The severity of anaphylaxis associated with the presence immunoglobulin E (IgE) antibodies that bind to allergens high affinity. Here, we report development unique Interleukin-13 (IL-13)-producing follicular helper T (TFH) cell subset, designated TFH2 cells, which tightly production high-affinity IgE antib...

The co-stimulatory molecule CD28 is essential for activation of helper T cells. Despite this critical role, it is not known whether CD28 has functions in maintaining T cell responses following activation. To determine the role for CD28 after T cell priming, we generated a strain of mice where CD28 is removed from CD4(+) T cells after priming. We show that continued CD28 expression is important ...

Antigen-specific helper T cells are required in the generation of cytotoxic T cells from thymocyte precursors. We have demonstrated that these alloantigen-specific helper cells can be generated in vitro and that both the quantity and quality of the helpers appear to be superior to the help obtained from unprimed spleen cells. Optimal helper cell activity is produced at day two of culture when C...