The classical type of programmed cell death is characterized by its dependence on de novo RNA and protein synthesis and morphological features of apoptosis. We confirmed that stimulated 2B4.11 (a murine T-cell hybridoma) and interleukin-3 (IL-3)-deprived LyD9 (a murine haematopoietic progenitor cell line) died by the classical type of programmed cell death. Assuming that common biochemical pathways might be involved in the deaths of 2B4.11 and LyD9, we isolated the PD-1 gene, a novel member of the immunoglobulin gene superfamily, by using subtractive hybridization technique. The predicted PD-1 protein has a variant form of the consensus sequence found in cytoplasmic tails of signal transducing polypeptides associated with immune recognition receptors. The PD-1 gene was activated in both stimulated 2B4.11 and IL-3-deprived LyD9 cells, but not in other death-induced cell lines that did not show the characteristic features of the classical programmed cell death. Expression of the PD-1 mRNA in mouse was restricted to the thymus and increased when thymocyte death was augmented by in vivo injection of anti-CD3 antibody. These results suggest that activation of the PD-1 gene may be involved in the classical type of programmed cell death.

https://www.embopress.org/doi/epdf/10.1002/j.1460-2075.1992.tb05481.x

Induced expression of PD-1, a novel member of the immunoglobulin gene superfamily, upon programmed cell death.

CD44 is the principal cell surface receptor for hyaluronate.

Cell-adhesion molecules, once believed to function primarily in tethering cells to extracellular ligands, are now recognized as having broader functions in cellular signalling cascades. The CD44 transmembrane glycoprotein family adds new aspects to these roles by participating in signal-transduction processes — not only by establishing specific transmembrane complexes, but also by organizing signalling cascades through association with the actin cytoskeleton. CD44 and its associated partner proteins monitor changes in the extracellular matrix that influence cell growth, survival and differentiation.

CD44: From adhesion molecules to signalling regulators

Signal transduction by lymphocyte antigen receptors

Hyaluronan is an extracellular and cell-surface-associated polysaccharide that is traditionally regarded as a biological 'goo' that participates in lubricating joints or holding together gel-like connective tissues. Although these are common physiological roles of hyaluronan in adult organisms, hyaluronan also functions as a microenvironmental cue that co-regulates cell behaviour during embryonic development, healing processes, inflammation and tumour development. Recent work highlights a key role for interactions between hyaluronan and tumour cells in several aspects of malignancy and indicates the possibility of new therapeutic strategies.

Hyaluronan: from extracellular glue to pericellular cue

A lymphocyte molecule implicated in lymph node homing is a member of the cartilage link protein family

CD44 is a polymorphic integral membrane protein which recognizes hyaluronate and whose proposed roles encompass lymphocyte activation, matrix adhesion and the attachment of lymphocytes to lymph node high endothelial venules (HEVs) Immunochemical and RNA blot data have supported the existence of two forms of CD44: a hematopoietic form expressed by cells of mesodermal origin (and by some carcinoma cell lines) and an epithelial form weakly expressed by normal epithelium but highly expressed by carcinomas This report describes the isolation of a cDNA encoding a distinct CD44 polypeptide expressed by epithelial cells Re-expression of each form of CD44 in a B cell line allowed cells transfected with the hematopoietic but not the epithelial form to bind to viable rat lymph node HEV cells in primary culture

https://www.embopress.org/doi/pdf/10.1002/j.1460-2075.1991.tb07955.x

The hematopoietic and epithelial forms of CD44 are distinct polypeptides with different adhesion potentials for hyaluronate-bearing cells.

Sequence requirements for induction of cytolysis by the T cell antigen Fc receptor ζ chain

A simple and highly efficient method for cloning cDNAs from mammalian expression libraries based on transient expression in mammalian host cells has been discovered. The present invention specifically provides the CD40 cDNA sequence.

Martine Amiot

Papers

A lymphocyte molecule implicated in lymph node homing is a member of the cartilage link protein family

The hematopoietic and epithelial forms of CD44 are distinct polypeptides with different adhesion potentials for hyaluronate-bearing cells.

Sequence requirements for induction of cytolysis by the T cell antigen Fc receptor ζ chain

CD40 coding sequences

Activation of immune system effector function by T-cell or Fc receptor intracellular domains.