Jack R. Bennink

Characteristics of secondary cytotoxic T-cell responses in mice infected with influenza A viruses

Abstract The cytotoxic T-cell response in mice infected with type A influenza viruses is dominated by a highly cross-reactive component. Previous experiments showed that after primary immunization the cytotoxic T-cell response apparently consists of a small but significant portion which is specific for the immunizing virus, and a larger component which is highly cross-reactive among all A strain viruses. The present study concentrates on the specificity of the T-cell response after secondary stimulation, using various combinations of type A virus strains. The underlying rationale was to determine whether there was any discernable pattern in the T-cell response which parallels the serologically defined antigenic pattern of influenza. That a virus strain-specific set of precursors does exist was evident in the primary response and even more so upon secondary challenge with the homologous virus (using an adoptive transfer protocol). However, upon secondary challenge with a heterologous influenza virus, this specific component was not evident no matter how closely related serologically the two challenge viruses were. No obvious relationships could be found between serologically defined antigenic patterns and the capacity to stimulate a secondary T-cell response specific for a particular type A influenza virus.

The response to H-2-different virus-infected cells is mediated by long-lived T lymphocytes and is diminished by prior virus priming in a syngeneic environment☆

Abstract Immunologically naive C57BL/6J(B6, H-2K b D b ) T cells can, after negative selection in vivo to remove alloreactive lymphocytes, be induced to respond to H-2K k -vaccinia virus when primed in irradiated B10.A(4R) (H-2K k D b ) recipients. Precursors with the capacity to generate cytotoxic T-lymphocyte (CTL) effector function specific for H-2K k -vaccinia virus are present in the long-lived, recirculating T-cell pool. However, prior priming of the B6(H-2 b ) mice with vaccinia virus abrogates the responder potential of the H-2 b CTL for H-2K k -vaccinia virus. Furthermore, addition of primed to unprimed H-2 b T cells greatly diminishes the response of the naive lymphocyte populations. A possible mechanism for this suppression is that the expanded pool of memory CTL specific for H-2D b -vaccinia virus eliminates the resident B10.A(4R) stimulator cells before the primary response to H-2K k -vaccinia virus is sufficiently developed.

Limiting dilution analysis of memory cytotoxic T lymphocytes specific for individual influenza virus gene products

The frequency of memory T cells specific for individual influenza virus gene products in the spleens of BALB/c mice primed with A/Puerto Rico/8/34/1(H1N1) (PR8) influenza A virus was determined by using limiting dilution protocols. The results confirm that the influenza virus nucleoprotein (NP) is the predominant protein recognized by BALB/c cytotoxic T lymphocyte (CTL). This was true whether the responder splenocytes were restimulated with homologous PR8 virus or heterologous A/Japan/305/57 (H2N2) (JAP). The frequency hierarchy for BALB/c splenocytes restimulated with PR8 was NP greater than PB2 greater than or equal to H1 greater than NS1 greater than H2. The frequency of CTL specific for all other influenza gene products was too low to calculate. The CTL hierarchy for BALB/c splenocytes restimulated with JAP was NP greater than NS1, with all others lower than 1 in 96,000.

Negative selection experiments support the idea that T-T help is required for the H-Y-specific cytotoxic T cell response☆

Abstract Antigen-primed female thoracic duct lymphocyte (TDL) populations (B6, H-2K b I-A b D b ) were depleted of T cells specific for the male H-Y antigen presented in the context of I-A b , by negative selection through irradiated male H-2K b I-A b D b recipients. This ocedure substantially removed the capacity of such TDL to respond to H-Y-H-2D b . The response can be reconstituted by adding either smaller numbers of unfiltered, H-Y-primed, B6 female TDL or anti-Ly-2-treated memory T cells. The results thus support the idea that concurrent presence of helper T cells specific for H-Y-H-2-I-A b is required for the generation of secondary cytotoxic T lymphocyte responses to H-Y-H-2D b . This is discussed in the context of similar, though not identical, experiments with the vaccinia virus model.

Use of Recombinant Vaccinia Viruses to Examine Cytotoxic T Lymphocyte Recognition of Individual Viral Proteins

Cytotoxic T lymphocytes (CTL) are believed to play an important role in immunity to tumors and viruses.1 CTL recognize foreign antigens in conjunction with class I major histocompatibility complex (MHC) molecules, and act by either directly lysing cells bearing the foreign antigen, or by releasing molecules with anti-viral and/or anti-tumor activities.2–4 Understanding of CTL has been hindered by difficulties in identifying which foreign antigens are recognized on the target cell surface. We have addressed this problem using recombinant vaccinia viruses containing individual cloned genes from two well characterized viruses which have been extensively used in previous studies of CTL specificity and function, influenza virus (a myxovirus), and vesicular stomatitis virus (a rhabdovirus).

Primary pulmonary murine cytotoxic T lymphocyte specificity in respiratory syncytial virus pneumonia

Effector cells capable of lysing respiratory syncytial virus (RSV)-infected cells were isolated from the lungs of intranasally infected mice. An examination of their specificity showed that cytolysis was major histocompatibility complex restricted. Using recombinant vaccinia viruses containing cloned RSV genes to infect target cells, BALB/c (H-2d) pulmonary effector cells were shown to recognize the fusion protein (F) and to a lesser extent the nucleoprotein (N). Cells specific for the major glycoprotein (G) or the small hydrophobic protein (1A) were not observed.

A monoclonal antibody to an interspecies major histocompatibility determinant inhibits a virus-specific T-cell clone☆

Abstract The cytotoxicity of an influenza-specific T-cell clone of BALB/c mouse origin for an H-2 compatible, virus-infected target is greatly inhibited by a monoclonal antibody which binds to mouse major histocompatibility complex (MHC) determinants, but was originally prepared against MHC antigens of the Brown Norway (BN) rat. The inhibition is still observed after absorption of the antibody with lymphoid cells from Lewis, but not from BN or Lewis. l N rats. It thus seems that the site blocked by this monoclonal antibody, which interacts with MHC antigens from a number of animal species, is at least close to a determinant on the MHC glycoprotein that is involved in T-cell recognition. This reagent may be useful for comparative analysis of the phylogeny of MHC-restricted T-cell responses in different species.

Thymocytes can be stimulated to give a strong vaccinia virus-immune cytotoxic T lymphocyte response

The emergence of virus-specific cytotoxic T lymphocyte (CTL) precursors in thymus can be examined directly by stimulating thymocytes for 6 days in irradiated, virus-infected recipients. Responsiveness is a characteristic of the thymocytes themselves and does not reflect the presence of contaminating, blood-bourne T cells. Strong CTL activity may be generated earlier from thymus than from spleen or lymph node of lethally irradiated, bone marrow reconstituted mice. Also, the reconstitution of virus-immune CTL function in these peripheral lymphoid organs is thymus-dependent. Use of this simple experimental protocol offers considerable possibilities for the analysis of the role of the thymus in the ontogeny of the T cell repertoire.

The Dual Specificity of Virus-Immune T Cells

A current obsession of cellular immunology is the definition of the T-cell receptor repertoire. Many of the questions that have been raised derive from experiments with virus systems (Doherty et al., 1976a; Zinkernagel and Doherty, 1979). How do we explain the apparent dual specificity for major histocompatibility (MHC) components and for virus?