CTL that possess a high functional avidity are known to be optimal for the clearance of pathogens in vivo. We have shown that the amount of peptide encountered by a CD8+ CTL determines its functional avidity. Notably, in these studies nonprofessional APC were used. However, it is mature dendritic cells (DC) that are predominantly responsible for the activation of naive T cells in vivo. Whether ...

Twenty-two recipients of HLA-nonidentical living related and nonrelated renal allografts were studied for alterations in the relative percentage of OKT4-positive peripheral blood T-cells after transplantation. Characteristic shifts in the ratio of T-helper to T -suppressor/cytotoxic cells (TH/TS-C), but not absolute cell numbers, were demonstrated to correspond with the status of the allog...

Background:  Natural Killer cells express killer inhibitory receptors specific for HLA-class I molecules.  These receptors could induce signals that determine NK cells ability to mediate cytotoxicity.  Purified soluble form of HLA class I molecules (sHLA) could bind to NK cell receptors and down-regulate the NK killer function. Objective:  To evaluate the influence of sHLA and two monoclonal an...

We compared the cytotoxic activities of thymus-dependent and thymus-independent CD8(+) T cells. Thymus-dependent CD8(+) T cells, which are foreign antigen specific, acquired cytotoxic activity to tumor cells with a basal dose of the antigen peptides and to hybridoma cells expressing anti-TCR mAb only after differentiation into effector cytotoxic T lymphocytes (CTL). In contrast, thymus-independ...

Cytotoxic T cells were detected in the cervical lymph nodes, lungs, spleen, and peripheral blood of mice with influenza. Lymphocytes decreased in the peripheral circulation and increased in the lung during the period of acute inflammation and pneumonia. Peak cytotoxic T-cell activity was present at the time of marked pulmonary infiltration, and it decreased with resolution of the pneumonia. The...