The role of CD4 T cell help in restoring function of exhausted CD8 T cells during chronic infection

Ratio of CD4+ to CD8+ T-Cells in the Recent Reported Cases of Bird Flu Infection in Asia

CD4+ T Cells are Exhausted and Show Functional Defects in Chronic Lymphocytic Leukemia

Background: Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the western world. This health problem is caused due to the accumulation of mature B-lymphocytes in the peripheral blood and bone marrow. In the course of cancer, CD4+ T cells become “exhausted” and characterized with poor effector functions and the expression of multiple inhibitory receptors. Objective: To inve...

Role of CD4 T cell help and costimulation in CD8 T cell responses during Listeria monocytogenes infection.

CD4 T cells are known to assist the CD8 T cell response by activating APC via CD40-CD40 ligand (L) interactions. However, recent data have shown that bacterial products can directly activate APC through Toll-like receptors, resulting in up-regulation of costimulatory molecules necessary for the efficient priming of naive T cells. It remains unclear what role CD4 T cell help and various costimul...

Expansion of CD4+CD25+FoxP3+ Regulatory T Cells in Chronic Hepatitis C Virus Infection

Background: Regulatory T cells (Tregs) have been involved in impaired immunity and may have a pivotal role in persistence of viral infections. Objective: To develop a simple and reliable in-house three color flow cytometery of peripheral blood to understand the role of HCV infection in the increase of Tregs. Methods: The level of naturally occurring CD4+CD25+FoxP3+ regulatory T cells (nTregs) i...

Rejuvenating Exhausted T Cells during Chronic Viral Infection

In a recent paper in Nature, show that the immunoreceptor PD-1 is upregulated by "exhausted" T cells during the chronic phase of viral infection in mice. Remarkably, blocking the interaction between PD-1 and its ligand, PD-L1, reactivates these T cells and reduces viral load.