From 1 to 23% of fetal human spleen or thymus cells (from the 20th to 24th week of gestation) were found to display a previously unrecognized CD2-/CD3+ phenotype. IL-2-dependent, long-term clones of CD2-/3+ T cells did not react with a panel of anti-CD2 mAbs and did not form rosettes with sheep erythrocytes. These results show that (a) significant numbers of CD2-/3+ T cells are present in fetal...

Accessory cell surface molecules, such as T cell antigen CD2 and its ligand lymphocyte function-associated antigen 3 (LFA-3; CD58), are critical costimulatory pathways for optimal T cell activation in response to antigens. Interaction of CD2 with cell surface LFA-3 not only increases T cell/accessory cell adhesion, but also induces signal transduction events involved in the regulation of T cell...

The relationship between intermembrane spacing, adhesion efficiency, and lateral organization of adhesion receptors has not been established for any adhesion system. We have utilized the CD2 ligand CD48 with two (wild type CD48 (CD48-WT)), four (CD48-CD2), or five (CD48-CD22) Ig-like domains. CD48-WT was 10-fold more efficient in mediating adhesion than CD48-CD2 or CD48-CD22. Electron tomograph...

The adhesion interaction between the immunoglobulin superfamily molecules CD2 and CD58 (lymphocyte function-associated antigen 3) plays an important role in T cell and natural killer cell interaction with various antigen-presenting and target cells. Determination of the solution structure of rat CD2 domain 1 has allowed a model of human CD2 domain 1 to be generated, and a series of mutants base...

We examined the prognostic impact of CD2 antigen expression for 651 patients with T-lineage acute lymphoblastic leukemia (ALL), who were enrolled in front-line Childrens Cancer Group treatment studies between 1983 and 1994. There was a statistically significant correlation between the CD2 antigen positive leukemic cell content of bone marrow and probability of remaining in bone marrow remission...

Binding of Cd2+ to concanavalin A and the subsequent induction of saccharide-binding activity has been studied at pH 6.5. We found that Cd2+ bound to both metal sites, S1 and S2, and that Cd2+ alone would induce sugar binding in concanavalin A. Using the fluorescent sugar 4-methylumbelliferyl alpha-D-mannopyranoside we determined that full saccharide-binding activity was obtained only when the ...

The uptake of atrazine by rice seedlings (Oryza sativa L.) through plant roots from nutrient solution was investigated in the presence and absence of Cd2+ over an exposure period of four weeks. It was found that both atrazine and Cd2+ were toxic to rice seedlings. Both shoot and root biomasses decreased when the seedlings were exposed to increasing atrazine or Cd2+ concentrations in nutrient so...

The present study was undertaken to elucidate different requirements for CD2-mediated activation of naive (CD45RO-) and memory (CD45RO+) CD4+ T cells. A mitogenic combination of anti-CD2 (anti-T11(2) and anti-T11(3] mAbs could effectively induce the proliferation of memory CD4+ T cells even in the absence of monocytes. In marked contrast, naive CD4+ T cells did not disclose any proliferative re...

Nonessential metal ions such as cadmium are most likely transported across plant membranes via transporters for essential cations. To identify possible pathways for Cd2+ transport we tested putative plant cation transporters for Cd2+ uptake activity by expressing cDNAs in Saccharomyces cerevisiae and found that expression of one clone, LCT1, renders the growth of yeast more sensitive to cadmium...

CD2 subserves both adhesion and signal transduction functions in T cells, thymocytes, and natural killer (NK) cells. In mature T lymphocytes, CD2-mediated signaling function apparently requires surface expression of T cell receptors (TCRs). In contrast, in CD2+ CD3- NK cells and thymocytes, signal transduction through CD2 is TCR independent. To resolve this paradox and characterize TCR-independ...