▪ Abstract T cells play a central role in the initiation and regulation of the immune response
to antigen. Both the engagement of the TCR with MHC/Ag and a second signal are needed …

CD28 and CTLA-4 are related glycoproteins found on T cells. Ligation of CD28 following
antigen receptor engagement provides a costimulatory signal required for T cell activation. Anti-…

CTLA-4 is a CD28 homologue believed to be a negative regulator of T cell function. However,
the mechanism of this downregulatory activity is not well understood. The present study …

CTLA-4, a CD28 homologue expressed on activated T cells, binds with high affinity to the
CD28 ligands, B7-1 (CD80) and B7-2 (CD86). This study was designed to examine the role of …

In this report we have investigated the role of the Ets-1 transcription factor in the differentiation
of the NK cell lineage in mice. Splenic NK cells express high levels of Ets-1. Ets-1-…

Costimulation of T cell proliferation can occur through the CD28 signal transduction pathway.
In addition, other cell surface receptors, including the CD28 homolog CTLA-4, have been …

The importance of CD28 costimulation to a primary T cell response in vivo was assessed in
an adoptive transfer system where a small population of peptide-specific CD4+ TCR …

Background We compared the efficacy of the antiviral agent, remdesivir, versus standard-of-care
treatment in adults with severe coronavirus disease 2019 (COVID-19) using data from a …

The dimorphic bacterium Caulobacter crescentus has evolved marked phenotypic changes
during its 50-year history of culture in the laboratory environment, providing an excellent …

Cytotoxic T lymphocyte Ag-4 (CTLA-4; CD152) is an important T cell regulatory molecule. In
vitro experiments have shown that the blockade of signals through CTLA-4 augments T cell …