Search results for "H-2 Antigens"
showing 10 items of 24 documents
Dense Bodies of Human Cytomegalovirus Induce both Humoral and Cellular Immune Responses in the Absence of Viral Gene Expression
2000
ABSTRACTInfection of fibroblast cell cultures with human cytomegalovirus (HCMV) leads to the production of significant amounts of defective enveloped particles, termed dense bodies (DB). These noninfectious structures contain major antigenic determinants which are responsible for induction of both the humoral and the cellular immune response against HCMV. We tested the hypothesis that, by virtue of their unique antigenic and structural properties, DB could induce a significant immune response in the absence of infectious virus. Mice were immunized with gradient-purified DB, which were either left untreated or subjected to sequential rounds of sonication and freeze-thawing to prevent cellula…
T-T cell interactions during in vitro cytotoxic T lymphocyte responses. III. Antigen-specific T helper cells release nonspecific mediator(s) able to …
1980
T helper cell induction and the specificity of T cell-mediated help as generated during alloreactive and H-2-restricted, virus- or hapten-specific cytotoxic T lymphocyte (CTL) responses have been compared. With the use of a double-chamber culture system, it was possible to dissect and separately analyze the induction phase of T helper cells from the T helper cell effector function. The data obtained revealed that during alloreactive as well as H-2-restricted T cell responses, antigen-specific T helper cells are induced. Upon specific restimulation of T helper cells, helper cell function is mediated across a cell-impermeable membrane via soluble products in an apparently nonspecific and nonr…
Alloreactive and H-2-restricted Lyt 23 cytotoxic T lymphocytes derive from a common pool of antecedent Lyt 123 precursors.
1980
If the collaborative requirement of Lyt 1 T helper cells is bypassed by the Lyt 1 T cell-derived mediator of T help, termed Il-2, upon antigenic stimulation, PNA+ Lyt 123 thymocytes differentiate into either alloreactive or H-2-restricted PNA- Lyt 23 cytotoxic effector cells. Along the differentiation pathway from Lyt 123 leads to 23 effector cells, cytolytic activity is carried out by T cells that still express the Lyt 123 phenotype. The data establish that Lyt 23 CTL are produced by differentiation from antecedent Lyt 123 cells.
H-2(d) mice born to and reared by HBeAg-transgenic mothers do not develop T cell tolerance toward the hepatitis B virus core gene products.
2000
The function of the secretory core gene product (HBeAg) of the human hepatitis B virus (HBV) is unknown. It has been proposed that this protein may be passed from the mother to her offspring at the perinatal stage where it might induce immune tolerance. In a previous study we have shown that the murine placenta presents an efficient barrier for the HBe protein and that H-2(b) mice born to HBeAg-positive transgenic mothers do not develop tolerance of specific cytotoxic T cells. In the present work we demonstrate that transgenic mice expressing high serum levels of HBeAg secrete only small amounts of this protein into their milk and excrete minute amounts of the viral gene product in their ur…
Fine specificity and cytolytic activity of continuously growing alloreactive cytotoxic T lymphocyte clones.
1980
The role of Lyt 1+ T-cell-derived secondard CTL inducing factor allowed the cloning of alloreactive cytotoxic T lymphocytes (CTL) by the limiting dilution approach. Several monoclonal cell lines were established in vitro. The lytic activity of some of the cell lines exceeded that of CTL from bulk cultures; that is, 50% of the target cells were lysed at an effector to target cell ratio of 0.04:1. The fine specificity of individual CTL clones is discussed.
Herpes-Simplex-virus-specific, H-2Dk-restricted T lymphocytes bear receptors for H-2Dd alloantigen.
1980
Cytotoxic T lymphocytes generated in the course of an HSV-infection of CBA (H-2k) mice not only lyse syngeneic, virus-infected target cells but also cross-react with noninfected taraget cells expressing the Dd alloantigen. On the effector cell level, this alloreactivity is mediated by virus-specific CTL's that are restricted to H-2Dk determinants. On the prekiller cell level, the anti-HSV-reactive T cells exhibiting cross-reactivity for Dd alloantigen could be positively selected on H-2d spleen-cell monolayers. After differentiation into cytolytic effector cells, target cells expressing Dd alloantigens and syngeneic HSV-infected target were lysed with equal efficiency. The results imply tha…
Anti H-2Dd alloreactivity mediated by herpes-simplex-virus specific cytotoxic H-2k T lymphocytes is associated with H-2Dk.
1980
Herpes-simplex-virus (HSV) specific, H-2k-restricted, immune cytotoxic T lymphocytes also lyse noninfected H-2d target cells. Genetic mapping studies revealed that HSV-specific Dk-restricted CTL cross-react with allogeneic targets expressing Dd alloantigens. Cold target inhibition experiments indicate that only a minority of HSV-specific CTL mediate cross-reactive cytolysis. The data give an example of where the phenomenon of H-2-restricted versus nonrestricted responsiveness is not due to distinct subsets of T cells but solely depends on the antigenic determinants recognized.
Immunogenicity of enhanced green fluorescent protein (EGFP) in BALB/c mice: identification of an H2-Kd-restricted CTL epitope
2000
Enhanced green fluorescent protein (EGFP) is a novel marker gene product, which is readily detectable using techniques of fluorescence microscopy, flow cytometry, or macroscopic imaging. In the present studies, we have examined the immunogenicity of EGFP in murine models. A stable transfectant of the transplantable CMS4 sarcoma of BALB/c origin expressing EGFP, CMS4-EGFP-Zeo, was generated. Splenocytes harvested from mice immunized with a recombinant adenovirus expressing EGFP (Ad-EGFP) were restimulated in vitro with CMS4-EGFP-Zeo. Effector lymphocytes displayed strong cytotoxicity against CMS4-EGFP-Zeo, but not against mock-transfected CMS4-Zeo tumor cells. A number of candidate H2-Kd-bin…
Cross-reactivity between tumor MHC class I-restricted antigens and an enterococcal bacteriophage
2020
International audience; Intestinal microbiota have been proposed to induce commensal-specific memory T cells that cross-react with tumor-associated antigens. We identified major histocompatibility complex (MHC) class I-binding epitopes in the tail length tape measure protein (TMP) of a prophage found in the genome of the bacteriophage Enterococcus hirae Mice bearing E. hirae harboring this prophage mounted a TMP-specific H-2Kb-restricted CD8+ T lymphocyte response upon immunotherapy with cyclophosphamide or anti-PD-1 antibodies. Administration of bacterial strains engineered to express the TMP epitope improved immunotherapy in mice. In renal and lung cancer patients, the presence of the ent…
Major histocompatibility complex regulation of interleukin-5 production in the mouse.
1993
Lymph node cells of CBA (H-2k), but not of BALB/c (H-2d) mice immunized epicutaneously with picryl chloryde secrete interleukin (IL)-5 when stimulated with the specific antigen in vitro. The low IL-5 production in BALB/c mice persists when either picryl chloride or the unrelated antigen oxazolone are used, when the amount of antigen in vitro is varied and when a secondary response is studied. The difference in IL-5 production maps to the major histocompatibility complex (MHC) in the congenic BALB/b, BALB/c and BALB/k mice. Furthermore, lymph node cells from (k × d) F1 mice produce IL-5 when stimulated by antigen presented on H-2k but not on H-2d antigen-presenting cells. Finally, the low IL…