Excision of group II introns as circles has been described only for a few eukaryotic introns and little is known about the mechanisms involved, the relevance or consequences of the process. We report that splicing of the bacterial group II intron RmInt1 in vivo leads to the formation of both intron lariat and intron RNA circles. We determined that besides being required for the intron splicing ...

This study shows that, in humans at birth, circulating T cells represent recent thymic emigrants (RTEs) as reflected in their high level of expression of TCR excision circles. RTEs express "thymocyte-like" characteristics with regard to rapid rate of apoptosis. In the presence of common gamma-chain cytokines, in particular IL-7, they show enhanced potential to survive, entry into cell cycle, an...

Telomere maintenance is an essential characteristic of cancer cells, most commonly achieved by activation of telomerase. Telomeres can also be maintained by a recombination-based mechanism, alternative lengthening of telomeres (ALT). Cells using ALT are characterized by the presence of ALT-associated promyelocytic leukemia (PML) bodies (APB), long, heterogeneously sized telomeres, extrachromoso...

Telomere maintenance is an essential characteristic of cancer cells, most commonly achieved by activation of telomerase. Telomeres can also be maintained by a recombination-based mechanism, alternative lengthening of telomeres (ALT). Cells using ALT are characterized by the presence of ALT-associated promyelocytic leukemia (PML) bodies (APB), long, heterogeneously sized telomeres, extrachromoso...

In the construction of large antibody libraries by in vivo recombination, two non-homogeneous loxP sites are required for the exchange of V genes between phagemids to create many new VH-VL combinations. The mutated loxP511 was designed not to recombine with the wild-type loxP (loxPwt) in early studies and a combination of the two has been used to construct antibody libraries. But recent reports...

The xeroderma pigmentosum (XP) group D (XPD) gene encodes a DNA helicase that is a subunit of the transcription factor IIH complex, involved both in nucleotide excision repair of UV-induced DNA damage and in basal transcription initiation. Point mutations in the XPD gene lead either to the cancer-prone repair syndrome XP, sometimes in combination with a second repair condition; Cockayne syndrom...

Background: Screening newborns for severe combined immunodeficiency (SCID) has become essential, since efficient methods to identify infants with these disorders exist and early stem cell transplantation is life-saving. Method: We performed a three-year screening trial in Stockholm comprised of 89,462 newborn infants. The number of T-cell receptor excision circle (TREC)/kappa-deleting recombina...

One of the main of concerns in allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the profound and long-lasting immunodeficiency leaving patients highly susceptible to multiple infections. Accordingly, a low B-cell recovery after allo-HSCT has been associated with high infection rate. B-cell reconstitution is a slow process characterized by a relative increase of the percentage o...