Technique measures immunogenicity of TB vaccines.(tuberculosis)

2002 DEC 4 - (NewsRx.com & NewsRx.net) -- According to a study from the United States, "Previous studies in murine and human models have suggested an important role for CD8+ T cells in host defense to Mycobacterium tuberculosis (Mtb). Consequently, a successful tuberculosis vaccine may require the elicitation of sustained CD4+ and CD8+ T-cell responses."

D.A. Lewinsohn and colleagues at the Oregon Health & Science University, Portland VA Medical Center, conducted a study to see if "the potent CD4+ T-cell antigen Mtb39 is also a CD8+ T-cell antigen."

"A recombinant adenovirus-expressing Mtb39 (adenoMtb39) was used to infect monocyte-derived dendritic cells. Using interferon-gamma enzyme-linked immunospot, Mtb39-specific CD8+ T lymphocytes were detected in three healthy individuals with latent tuberculosis infection who also had strong anti-Mtb39-specific CD4+ T-cell responses," wrote the researchers.

"An Mtb39-specific CD8+ T-cell line was generated using Mtb39-expressing dendritic cells. Mtb39-specific T-cell clones were obtained by limiting dilution cloning. All seven T-cell clones obtained were HLA-B44 restricted," noted Lewinsohn and colleagues.

"Using a panel of synthetic overlapping peptides representative of Mtb39, the peptide epitope was identified for two clones. Furthermore, all T-cell clones recognized Mtb-infected dendritic cells and were ...