Improved HIV-1 specific T-cell responses by short-interval DNA tattooing as compared to intramuscular immunization in non-human primates

The new intradermal DNA delivery technique, termed DNA tattooing might overcome the discrepancy between the encouraging immunogenicity results obtained with DNA vaccines in murine studies and the poor results obtained in non-human primates and humans, the so called "simian barrier". Here, we demonstrate a 10- to 100-fold increase in the magnitude of vaccine specific T-cell responses in peripheral blood from DNA tattooed rhesus macaques, as compared to T-cell responses in animals immunized via intramuscular (IM) route. A marked increase in the magnitude of the antigen specific T-cell responses as well as an increase in the number of animals responding to the immunogens was observed. These findings in non-human primates suggest that similar results may be observed in humans. Clinical trials are planned to validate tattooing as an optimal method of DNA vaccine delivery in humans. © 2008 Elsevier Ltd. All rights reserved

Specific binding of antigenic peptides to cell-associated MHC class I molecules.

T lymphocytes recognize antigen in the form of peptides that associate with specific alleles of class I or class II major histocompatibility (MHC) molecules. By contrast with the clear MHC allele-specific binding of peptides to purified class II molecules purified solubilized class I molecules either bind relatively poorly or show degenerate specificity. Using photo-affinity labelling, we demonstrate here the specific interaction of peptides with cell-associated MHC class I molecules and show that this involves metabolically active processes

An H-YDb epitope is encoded by a novel mouse Y chromosome gene

Rejection of male tissue grafts by genotypically identical female mice has been explained by the existence of a male-specific transplantation antigen, H-Y (ref. 1), but the molecular nature of H-Y antigen has remained obscure. Hya, the murine locus controlling H-Y expression, has been localized to Delta Sxr(b), a deletion interval of the short arm of the Y chromosome(2). In mice, H-Y antigen comprises at least four distinct epitopes, each recognized by a specific T lymphocyte clone. It has recently been shown that one of these epitopes, H-YKk, is a peptide encoded by the Y-linked Smcy gene, presented at the cell surface with the H-2K(k) major histocompatibility complex (MHC) molecule(3). However, deletion mapping and the analysis of variable inactivation of H-Y epitopes has suggested that the Hya locus may be genetically complex(4,5). Here we describe a novel mouse Y chromosome gene which we call Uty (ubiquitously transcribed tetratricopeptide repeat gene on the Y chromosome). We identify the peptide WMHHNMDLI derived from the UTY protein as an H-Y epitope, H-YDb. Our data formally demonstrate that H-Y antigen is the product of more than one gene on the Y chromosome