We have investigated the possibility of inducing cytotoxic T lymphocytes (CTL) to Ras containing a mutation at position 61 or to normal Ras, using recombinant vaccinia viruses expressing these proteins. CTL from C57Bl/10 mice immunized with vaccinia expressing mutant Ras showed specificity for the mutant Ras protein and recognition of normal Ras was inefficient. The opposite specificity was obs...

Naive T cells differentiate into various effector T cells, including CD4(+) helper T cell subsets and CD8(+) cytotoxic T cells (CTL). Although cytotoxic CD4(+) T cells (CD4 +: CTL) also develop from naive T cells, the mechanism of development is elusive. We found that a small fraction of CD4(+) T cells that express class I-restricted T cell-associated molecule (CRTAM) upon activation possesses ...

In this study, we used mice in which the gene for gamma interferon (IFN-gamma) has been disrupted (IFN-gamma-/- mice) to study the role of this cytokine in the resolution of Chlamydia trachomatis infection. We show that IFN-gamma-/- mice are impaired in the ability to clear infection with C. trachomatis compared to IFN-gamma+/+ control mice. Activated CD8(+) cytotoxic T lymphocytes (CTL) secret...

Triggering of 4-1BB, a member of the TNFR family, through in vivo administration of agonistic anti-4-1BB Ab delivers a powerful costimulatory signal to CTL. We found this signal to effectively replace the need for CD4(+) T cell help in the cross-priming of tumor-specific CTL immunity. Furthermore, 4-1BB Ab can convert an otherwise tolerogenic peptide vaccine into a formulation capable of effici...

Dendritic cell (DC)-based immunotherapeutics must induce robust CTL capable of killing tumor or virally infected cells in vivo. In this study, we show that RNA electroporated post maturation and coelectroporated with CD40L mRNA (post maturation electroporation (PME)-CD40L DC) generate high-avidity CTL in vitro that lyse naturally processed and presented tumor Ag. Unlike cytokine mixture-matured...

Replication-deficient viruses provide an attractive alternative to conventional approaches used in the induction of antiviral immunity. We have quantitatively evaluated both the primary and memory cytotoxic T-lymphocyte (CTL) responses elicited by immunization with a replication-deficient mutant of herpes simplex virus type 1 (HSV-1). In addition, we have examined the potential role of these CT...

Host immunologic factors, including human immunodeficiency virus (HIV)-specific cytotoxic T lymphocytes (CTL), are thought to contribute to the control of HIV type 1 (HIV-1) replication and thus delay disease progression in infected individuals. Host immunologic factors are also likely to influence perinatal transmission of HIV-1 from infected mother to infant. In this study, the potential role...

We studied the mechanism of lymphocytic choriomeningitis virus (LCMV) persistence and the suppression of cytotoxic T lymphocyte (CTL) responses in BALB/c WEHI mice infected at birth with LCMV Armstrong strain. Using adoptive transfer experiments we found that spleen cells from persistently infected (carrier) mice actively suppressed the expected LCMV-specific CTL response of spleen cells from n...

Major histocompatibility complex (MHC)-restricted cytotoxic T lymphocytes (CTL) are part of the cellular immune response to human persistent virus infections. Measurements of the frequency and specificity of human immunodeficiency virus type 1 (HIV-1)-specific CTL and their variation with time may indicate their relative importance in modulating the progression of HIV-1 infection. We have used ...

Background: Herpes simplex virus type 1 is one of the most common viruses among human population. Studies demonstrate the essential role of cell mediated immunity, especially CD8+ T cells, in prevention and clearance of HSV1. Objective: It is of great importance to improve our knowledge about the kinetics of CTL responses to primary and secondary HSV-1 infection. Methods: Using a sensitive tech...