Biomedical subjects

T Tallone

Publications and source records attributed to T Tallone.

3 recordsLinked to original sources

PubMed2001

A mouse model for adenovirus gene delivery.

The cellular attachment receptor for adenovirus (Ad), Coxsackie adenovirus receptor (CAR), required for delivery of Ad into primary cells, is not present on all cell types, thus restricting Ad-gene delivery systems. To circumvent this constrain, a transgenic mouse has been generated that expresses a truncated human CAR in all tissues analyzed. These mice allowed efficient in vitro infections at low multiplicities into lymphoid, myeloid, and endothelial cells. Furthermore, in vivo administration of Ad-vectors results in infection of macrophages, lymphocytes, and endothelial cells. In addition, tail vein injection resulted in targeting of virus into previously inaccessible areas, such as the lung and the capillaries of the brain. The CAR transgenic mice will be useful for rapid functional genomic analysis in vivo, for testing the efficacy of gene therapy procedures or as a source of easily transducible cells.

Adenoviridae↗

PubMed2001

Deletion of the DQ52 element within the Ig heavy chain locus leads to a selective reduction in VDJ recombination and altered D gene usage.

The process of V(D)J recombination that leads to the assembly of Ig gene segments is tightly controlled during B cell differentiation. Two germline transcripts, one of which (mu(0)) originates from the promoter region of DQ52, may control the accessibility of the heavy chain locus. Here, we present the analysis of a mouse line in which the DQ52 gene together with its regulatory sequences is deleted by a Cre/loxP-based strategy. In F(1) (DQ52(+/-)) mice, the use of the JH3 and JH4 elements in DJ or VDJ junctions of the DQ52(-) allele was strongly reduced in both the bone marrow pre-B and spleen cells, while the JH1 and JH2 elements were used with normal frequencies. In addition, IgM(+) B cells of bone marrow and spleen used the DQ52(-) allele less frequently. On DJ joints of the DQ52(-) allele, there was 2 times less processing of JH3 ends, which resulted in clearly increased addition of P nucleotides. Although the use of D elements in DJ joints was quite similar, an altered D repertoire was found in VDJ joints of the DQ52(-) allele. In splenic B cells of the DQ52(-/-) mouse the amino acid distribution of the CDR3 was skewed, probably to compensate for the altered processing of JH3 ends. Thus, we have shown an interesting selective effect of the DQ52 region on controlling accessibility to 3' JH elements on the Ig locus, which also seems to influence the processing of DJ joints. We propose a model in which the DQ52 promoter region enhances the induction of secondary DJ rearrangements.

Alleles↗

PubMed1994

Active, interactive, and inactive steroid receptor mutants.

In transient co-transfection assays, there is extensive cross-interaction between glucocorticoid receptor (GR) domains. For example, mutation of the conserved Ile residue at position 484 (rat GR map) to cysteine allows a net separation of transactivation and DNA binding. We also observed that the ligand binding domain plays a key role in cooperative transactivation. Furthermore, some carboxy-located mutations markedly alter the response of GR to agonists and antagonists. Finally, different reading frames of the CAG repeat that normally produces an amino-located poly-Gln repeat profoundly affect GR transactivation without altering DNA or ligand binding. This trans-dominant negative phenotype, seen when the CAG repeat yields a poly-Ala stretch, may turn out to be an excellent tool for functional analysis of GR in transgenic organisms.

Amino Acid Sequence↗