Antibodies prepared against a human papilloma virus‐1 (HPV‐1) E4/beta‐galactosidase fusion protein identified several polypeptides in HPV‐1, but not HPV‐2 or 4, induced papillomas. The major E4 protein, that represented up to 30% of total cellular protein, was a 16/17‐K doublet which was purified by column chromatography and analysed for amino acid content. A peptide derived by chymotryptic digestion was purified by h.p.l.c. and subjected to amino acid sequencing. The unique sequence obtained, Gly‐His‐Pro‐Asp‐Leu‐Ser‐Leu, identified the 16/17‐K doublet as a product of the HPV‐1 E4 gene region. Antibodies to both the E4/beta‐galactosidase fusion protein and the 16/17‐K doublet identified two smaller polypeptides (10/11‐K) which may represent spliced products of E4. We propose that the products of the HPV‐1 E4 gene region are not classical DNA tumor virus early proteins and suggest that they play a role in virus maturation.

SUMMARYBovine tuberculosis is a threat to animal and human health in several countries. Greater understanding of the immunology of the disease is required to develop improved tests and vaccines. This study has used a model of bovine tuberculosis, established in the natural host, to investigate the dynamic changes that occur in the circulating T-cell subpopulations after infection. When the phenotypic composition of the peripheral blood lymphocytes was determined pre-and post-experimental infection, the response to disease comprised three phases. Firstly, the WC1/gd T cells decreased and then increased, suggesting localization to developing lesions and clonal expansion. Secondly, the CD4 : CD8 ratio increased. Thirdly, the CD4 : CD8 ratio decreased to less than pre-infection measurements. The latter changes suggested sequential involvement of CD4 and then CD8 T cells. The proportion of cells expressing interleukin-2 receptor (IL-2R) also increased. Panels of T-cell clones were established at various stages post-infection and all clones that exhibited antigen responsiveness were phenotyped. T-cell clones from early infection were WC1/gd and CD4 in phenotype, while CD8 clones appeared later in infection, eventually becoming dominant. Therefore, from in vivo and in vitro evidence, it was suggested that there is a dynamic progression in the T-cell subpopulations involved dominantly in responses to mycobacteria.

The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research. NBER working papers are circulated for discussion and comment purposes. They have not been peerreviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.

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