We have established a murine model system for exploring the ability of a CD4 subset-deficient host to cope with cytomegalovirus infection, and reported three findings. First, an antiviral response of the CD8 subset of T lymphocytes could be not only initiated but also maintained for a long period of time despite a continued absence of the CD4 subset, whereas the production of antiviral antibody...

A high grade T cell malignant lymphoma is described in which weak staining of tumour cells for leucocyte common antigen and T cell markers coexisted with strong positive cytoplasmic staining with the anticytokeratin marker CAM 5.2. This is the first report of non-CD30 positive T cell lymphoma showing cytokeratin positivity. On ultrastructural examination there was no evidence of epithelial diff...

A high grade T cell malignant lymphoma is described in which weak staining of tumour cells for leucocyte common antigen and T cell markers coexisted with strong positive cytoplasmic staining with the anticytokeratin marker CAM 5.2. This is the first report of non-CD30 positive T cell lymphoma showing cytokeratin positivity. On ultrastructural examination there was no evidence of epithelial diVe...

TOLERANCE (which is antigen-specific) must be distinguished from immune deficiency (non-specific). Its most important manifestation, the maintenance of SELFTOLERANCE, was originally explained by the Clonal Selection theory as the result of CLONAL ABORTION of self-reactive clones. However, potentially self-reactive Tand B-cells do exist in normal individuals, leading to the recognition of the im...

CD4 help for CD8(+) T lymphocytes prevents tolerance and promotes the survival of effector and memory CD8(+) T cells. Here, we describe additional helper functions that require CD4(+) T cells within the tumor environment. CD8(+) T-cell recruitment, proliferation, and effector function within the tumor were greatly enhanced by tumor-specific CD4(+) T cells. Recruitment of CD8(+) T cells was acce...