Cytolytic T-lymphocytes (CTL) can be repeatedly stimulated in L5178Y cell tumor-dormant DBA/2 mice by the i.p. inoculation of 2 X 10(6) X-irradiated L5178Y cells. The restimulated CTL activity has the same kinetics of generation and decline and the same target cell specificity as does the CTL response generated during establishment of the L5178Y cell tumor dormant state. No increase in adherent...

The correlation between virus load and specific cytotoxic T-lymphocyte (CTL) frequency during the chronic phase in human immunodeficiency virus type 1 (HIV-1) infection has been found to be negative in cross-sectional studies. We report here that, in infection with the related retrovirus human T-cell leukaemia virus type 1 (HTLV-1), the correlation is positive in asymptomatic carriers and zero ...

PURPOSE This multicenter randomized trial was designed to evaluate whether melanoma helper peptides augment cytotoxic T lymphocyte (CTL) responses to a melanoma vaccine and improve clinical outcome in patients with advanced melanoma. EXPERIMENTAL DESIGN One hundred seventy-five patients with measurable stage IV melanoma were enrolled into 4 treatment groups, vaccinated with 12 MHC class I-res...

Transforming growth factor beta (TGF-beta) is a potent immunosuppressive cytokine that is produced by neoplastic and normal cells. It has not been demonstrated directly, however, that TGF-beta can inhibit antigen-specific T-cell responses to tumor cells in vitro. We show here that generation of antitumor cytotoxic T-lymphocyte (CTL) activity in mixed-lymphocyte tumor cultures of splenocytes fro...

We previously reported that insulin-specific, MHC class I-restricted CTL precursors can be primed by injecting C57BL/6 mice with bovine insulin in CFA. These bovine insulin-primed CTL displayed a type 0 CTL phenotype, producing IL-4, IL-5, IL-10, low levels of IFN-gamma, but no TNF-alpha. By contrast, CTL generated from C57BL/6 mice primed with OVA in CFA produced IFN-gamma and TNF-alpha but no...

Although CD8(+) CTLs are presumed to be an important mediator of protective immunity in HIV-1 infection, the factors that determine CTL antiviral efficiency are poorly understood. Two factors that have been proposed to influence CTL antiviral function are antigenic avidity and epitope specificity. In this study we evaluate these by examining the activity of HIV-1-specific CTL against acutely in...

Mutations that abrogate recognition of a viral epitope by class I-restricted cytotoxic T lymphocyte (CTL) can lead to viral escape if the CTL response against that epitope is crucial for viral clearance. The likelihood of this type of event is low when the CTL response is simultaneously directed against multiple viral epitopes, as has been recently reported for patients with acute self-limited ...

Previously, we identified human papillomavirus type 16 (HPV-16) E5 as a tumor rejection antigen that can induce cytotoxic T lymphocytes (CTLs) to protect against tumor growth (D. W. Liu et al., J. Virol. 74:9083-9089, 2000). In the present study, we further mapped the CTL epitope of E5 protein by analyzing E5-specific CD8(+) gamma interferon-positive (IFN-gamma(+)) double-positive cells in C57B...

Cytotoxic T lymphocyte (CTL)-mediated killing of virus infections and tumors occurs over a wide range of conditions. The spatial environments in which CTLs encounter target cells vary from narrow vessels, to two-dimensional epithelial tissues, to densely populated 3-dimensional (3D) T cell areas within lymphoid tissues. How such spatial environments alter the functional response of CTL-mediated...

Human immunodeficiency virus 1 (HW-1) infection is associated with a vigorous cellular immune response that allows detection of cytotoxic T lymphocyte (CTL) activity using fleshly isolated peripheral blood mononudear cells (PBMC). Although restricting class I antigens and epitopes recognized by HIV-l-specific CTL have been defined, the effector cells mediating this vigorous response have been c...