The NH2-terminal domain of rat CD2 binds rat CD48 with a low affinity and binding does not require glycosylation of CD2.

CD2, CD48 and CD58 are structurally similar cell adhesion-molecules forming a subset of the immunoglobulin superfamily (IgSF). In humans CD58 is a ligand for CD2 while in mice CD2 binds CD48. We constructed a soluble chimeric molecule comprising the extracellular portion of rat CD48 and domains 3 and 4 of rat CD4 (sCD48-CD4) and used it to examine whether CD2 is a ligand for CD48 in rats.

The importance of cross-linking in the homotypic aggregation of lymphocytes induced by anti-leukosialin (CD43) antibodies.

Leukosialin (CD43) is a major glycoprotein of T lymphocytes which has an extracellular domain of 45 nm in length that is heavily O-glycosylated. Monoclonal antibodies (mAb) to the extracellular domain of human leukosialin induce aggregation of T lymphocytes, monocytes and some cell lines that express leukosialin. The aggregation was reported in one case to be inducible by Fab fragments.

IgE and IgG binding of peptides expressed from fragments of cDNA encoding the major house dust mite allergen Der p I.

Large peptides expressed from cDNA fragments of a clone encoding the mite allergen Der p I were able to bind IgE and IgG in sera from allergic individuals. The binding was found for peptides from sequences throughout the molecule, with at least five regions, comprising residues 1-56, 53-99, 98-140, 166-194, and 188-222. The only limitation was that more than 30 amino acid residues were required for consistent binding.

Structure of domain 1 of rat T lymphocyte CD2 antigen.

The CD2 antigen is largely restricted to cells of the T-lymphocyte lineage and has been established as an important adhesion molecule in interactions between human T lymphocytes and accessory cells. In the adhesion reaction, CD2 on T cells binds to LFA-3 on other cells, with binding through domain 1 of CD2. CD2 can also be a target for the delivery of mitogenic signals to T lymphocytes cultured with combinations of anti-CD2 antibodies.

The dimensions of the T lymphocyte glycoprotein leukosialin and identification of linear protein epitopes that can be modified by glycosylation.

Leukosialin (CD43) is a major glycoprotein of T lymphocytes whose extracellular domain of 224 amino acids contains on average one O-linked carbohydrate unit per three amino acids. This suggests an unfolded structure for the extracellular domain which has now been established to extend to a length of 45 nm by transmission electron microscopy following low angle rotary shadowing. The antigenicity of rat leukosialin has been studied using nine monoclonal antibodies (MAbs) whose binding is differentially affected by the cell type on which leukosialin is expressed and by the removal of sialic acid.

Protein sequence and gene structure for mouse leukosialin (CD43), a T lymphocyte mucin without introns in the coding sequence.

A partial cDNA clone for mouse leukosialin was isolated by use of a rat leukosialin cDNA probe. The mouse cDNA was then used to isolate genomic clones that corresponded to the two mouse genes detected in Southern blots. One gene encoded an open reading frame for the homologue of rat leukosialin and this gene was notable for the absence of introns within the coding sequence.