Biomedical subjects

E Tsitsikov

Publications and source records attributed to E Tsitsikov.

4 recordsLinked to original sources

PubMed2001

Altered sensitivity of CD81-deficient mice to neurobehavioral effects of cocaine.

CD81, also known as target of the antiproliferative antibody, is known to be expressed in astrocytes and involved in cell adhesion and, recently, we demonstrated its induction exclusively in the accumbens following cocaine. In the present study, the sensitivity of CD81-deficient mice to behavioral effects of cocaine was evaluated. It was found that CD81-deficient mice exhibited altered sensitivity to cocaine as assessed in the place preference conditioning paradigm and locomotor activity. This deficit in place preference conditioning was not accompanied by a deficit in acquisition or retention of water maze behavior. In addition, CD81 knockout mice exhibited higher levels of nucleus accumbens dopamine as compared to their controls. These observations are discussed in the context of the role of CD81 in cocaine-mediated behaviors.

Animals↗

PubMed1998

Impaired viability and profound block in thymocyte development in mice lacking the adaptor protein SLP-76.

The adaptor protein SLP-76 is expressed in T lymphocytes and myeloid cells and is a substrate for ZAP-70 and Syk. We generated a SLP-76 null mutation in mice by homologous recombination in embryonic stem cells to evaluate the role of SLP-76 in T cell development and activation. SLP-76-deficient mice exhibited subcutaneous and intraperitoneal hemorrhaging and impaired viability. Analysis of lymphoid cells revealed a profound block in thymic development with absence of double-positive CD4+8+ thymocytes and of peripheral T cells. This block could not be overcome by in vivo treatment with anti-CD3. V-D-J rearrangement of the TCRbeta locus was not obviously affected. B cell development was normal. These results indicate that SLP-76 collects all pre-TCR signals that drive the development and expansion of double-positive thymocytes.

Adaptor Proteins, Signal Transducing↗

PubMed1995

CD40-CD40 ligand (CD40L) interactions and X-linked hyperIgM syndrome (HIGMX-1).

Interactions between the B cell surface antigen CD40 and its ligand (CD40L) expressed on activated T cells play a critical role in isotype switching. This is illustrated by failure of isotype switching in patients with X-linked hyperIgM syndrome in whom the CD40L gene is mutated and by failure of isotype switching of CD40-deficient mice in response to T-cell-dependent antigens. We review these findings and discuss the signaling mechanisms of CD40 and the developmental control and transcriptional regulation of CD40L expression.

Animals↗

PubMedDate not supplied

CD40 ligand/CD40 deficiency.

CD40 is a surface antigen expressed on B cells. The CD40 ligand (CD40L) is expressed on activated T cells. Interaction between CD40 and CD40L is critical for proliferation and isotype switching in the context of a response to a T-cell-dependent antigen. Patients with X-linked hyper-IgM syndrome (HIGMX-1) in their CD40L gene are unable to switch from IgM to IgG, IgA and IgE. Mice with a disrupted CD40 gene fail to undergo isotype switching to T-cell-dependent antigens but respond normally to T-independent antigens.

Animals↗