CD4+ T cell help is important for the generation of CD8+ T cell responses. We used depleting anti-CD4 mAb to analyze the role of CD4+ T cells for memory CD8+ T cell responses after secondary infection of mice with the intracellular bacterium Listeria monocytogenes, or after boost immunization by specific peptide or DNA vaccination. Surprisingly, anti-CD4 mAb treatment during secondary CD8+ T ce...

The dynamics of when and where CD4(+) T cells provide help for CD8(+) T cell priming and which dendritic cells (DCs) activate CD4(+) T cells in vivo after localized infection are poorly understood. By using a cutaneous herpes simplex virus infection model combined with intravital 2-photon imaging of the draining lymph node (LN) to concurrently visualize pathogen-specific CD4(+) and CD8(+) T cel...

Cytotoxic effector phenotype and function of MHC-restricted Mycobacterium tuberculosis (MTB)-reactive CD4(+) and CD8(+) T lymphocytes were analyzed from healthy tuberculin skin test-positive persons. After stimulation in vitro with MTB, both CD4(+) and CD8(+) T cells up-regulated mRNA expression for granzyme A and B, granulysin, perforin, and CD95L (Fas ligand). mRNA levels for these molecules ...

In this paper we compare survival characteristics of transgenic and polyclonal CD4 and CD8 T cells. Transgenic CD4 T cells have an intrinsically lower capacity for survival, reflected in their gradual disappearance in thymectomized hosts, their increased sensitivity to apoptosis in vitro, and fewer divisions during homeostatic proliferation upon transfer into syngeneic lymphopenic hosts compare...

The functional capabilities of human peripheral blood CD3+CD4-CD8- and CD3+CD4+CD8+ T cell clones were examined. The clones were generated by culturing purified populations of CD3+CD4-CD8- and CD3+CD4+CD8+ T cells at limiting dilution (0.3 cell/well) in the presence of PHA, rIL-2, and irradiated PBMC as feeders. Twelve CD3+CD4-CD8- and 5 CD3+CD4+CD8+ clones were generated. Clonality was documen...

CD4+ T cells are essential for the maintenance of CD8+ memory T (Tm) cells following acute infection, but the importance of CD4+ T cells for the maintenance and expansion of CD8+ Tm cells to non-infectious antigens remains mostly unknown. Here, we showed that ovalbumin (OVA)-specific CD8+ Tm cell precursors derived from in vitro stimulation of TCR transgenic OT I CD8+ T cells with OVA protein-p...

Mature T lymphocytes possess a CD4 or CD8 lineage-specific marker. These molecules also serve as a co-receptor which along with a specific T Cell Receptor (TCR) binds to MHC class II (MHCII) or class I (MHCI), respectively. MHCI is expressed by all nucleated cells, whereas MHCII by antigen-presenting cells (APC). CD8 T cells kill target cells through MHCI-based recognition. CD4 T cells recogniz...

To evaluate the associations among immune cells (T-cells, B-cells, Macrophages and NK cells) in human endometrium during mid-luteal phase of menstrual cycle. Endometrial biopsies were obtained from 116 women (7 days after LH surge) natural cycles. The presence CD3-positive (T-cells), CD4-positive (T-helpers), CD8-positive (T-killers), CD14-positive (Macrophages), CD68-positive CD56-positive (NK...

CD4 can be up-regulated on CD8+ T cells generating a CD4dimCD8bright phenotype. We previously demonstrated that the CD4dimCD8bright phenotype constitutes an activated phenotype of CD8+ T cells. We demonstrate here that the activated CD4dimCD8bright T cells are not undergoing apoptosis and do not produce significant intracellular levels of interferon gamma (IFNgamma), interleukin 2 (IL-2), or IL...

Contact hypersensitivity (CHS) is a T cell-mediated response to hapten sensitization of the epidermis. The roles of CD4+ and CD8+ T cells in CHS have remained unclear, however, as studies to define either subset as the T cells mediating CHS have provided conflicting results. The goal of this study was to correlate the in vivo function of CD4+ and CD8+ T cells in CHS with the cytokines produced ...