PubMed Health⌕ Search

Biomedical subjects

U Kees

Publications and source records attributed to U Kees.

16 recordsLinked to original sources
PubMed1985

Identification of herpes simplex virus type 1 (HSV-1) glycoprotein gC as the immunodominant antigen for HSV-1-specific memory cytotoxic T lymphocytes.

The frequency and fine specificity of herpes simplex virus (HSV)-reactive cytotoxic T lymphocytes (CTL) of C57BL/6 mice was investigated in limiting dilution culture. The reactivity patterns of virus-specific CTL were assayed on target cells infected with HSV type 1, strain KOS, HSV type 2, strain Mueller, and mutants of HSV-1 (KOS) antigenically deficient or altered in glycoproteins gC or gB, two of the four major HSV-1-encoded cell surface glycoprotein antigens. Most CTL clones recognized type-specific determinants on target cells infected with the immunizing HSV serotype. In addition, the majority of HSV-1-specific CTL did not cross-react with cells infected with syn LD70, a mutant of HSV-1 (KOS) deficient for the presentation of cell surface glycoprotein gC. These data are the first demonstration of the clonal specificity of HSV-1-reactive CTL, and they identify gC as the immunodominant antigen. The fine specificity of gC-specific CTL clones was analyzed on target cells infected with mutant viruses altered in the antigenic structure of gC. These mutants were selected by resistance to neutralization with monoclonal antibodies, referred to as monoclonal antibody-resistant (mar) mutants. Most mar mutations in gC did not affect recognition by the majority of CTL clones. This indicated that most epitopes recognized by CTL are distinct from those defined by antibodies. The finding, however, that one mar mutation in gC affected both CTL and antibody recognition of this antigen may help to define antigenic sites important to both humoral and cell-mediated immunity to herpesvirus infection.

Animals↗
PubMed1984

A method for testing the specificity of influenza A virus-reactive memory cytotoxic T lymphocyte (CTL) clones in limiting dilution cultures.

This paper describes a system for determining the frequency and fine specificity of influenza A virus-immune memory cytotoxic T cell (CTL) clones from limiting dilution (LD) microcultures. We found that such experiments can only be performed (1) by analyzing the clonal response of CTL from wells of replica plates containing fractions of one original plate, (2) when it has been ascertained that splitting is possible at the clonal level, and that each fraction of a microculture well gives an identical response on target cells infected with the stimulating virus. With these requirements fulfilled we found that short term CTL clones from LD microcultures from influenza A virus (A/X-31)-immune mice (C57BL/6) occur at a frequency of f = 1:546 to f = 1:6303. The effector cells carry the Lyt-2.2 marker and are specific for target cells infected with the immunizing virus (influenza virus A/X-31). They do not lyse NDV (Newcastle disease virus) or HSV (herpes simplex virus)-infected or NK (YAC) target cells.

Animals↗
PubMed1984

Most influenza A virus-specific memory cytotoxic T lymphocytes react with antigenic epitopes associated with internal virus determinants.

This paper shows that most murine (C57BL/6) influenza A virus-specific memory cytotoxic T lymphocyte (CTL) clones tested in limiting dilution did not react with the influenza A virus surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). This lysis of syngeneic target cells infected with the influenza A virus strains, Aichi (H3N2), PR8 (H1N1), or recombinant strain X31 (H3N2) indicates that most antigenic epitopes recognized are associated with internal virus determinants. X31 and PR8 share the internal, and X31 and Aichi the external, viral determinants. Extensive CTL cross-reactivity was observed in experiments with target cells infected with virus carrying internal determinants homologous with the priming virus. In contrast, when the internal viral determinants differed between the priming virus and the virus used to infect the target cells, and although HA and NA were homologous, we found almost complete CTL-specificity for the priming virus. Thus, the predominant reactivity of influenza A virus-specific CTL differs from that of anti-influenza A antibodies, which are primarily directed towards epitopes on the virus surface glycoproteins. This finding may be relevant for the role of influenza A virus-specific CTL in recurrent infections with different influenza A viruses.

Animals↗
PubMed1984

Frequency and activity of immune interferon (IFN-gamma)- and colony-stimulating factor-producing human peripheral blood T lymphocytes.

This report describes the first frequency estimate of immune interferon (IFN-gamma)- and colony-stimulating factor (CSF)-producing human peripheral blood T lymphocytes. Human peripheral blood lymphocytes (HPBL) were activated with T cell mitogens [concanavalin A (Con A) or phytohemagglutinin (PHA)] in bulk culture and subsequently plated in limiting dilution (LD) microcultures in the presence of irradiated allogeneic HPBL filler cells and culture medium supplemented with human interleukin 2 and T cell mitogen (Con A or PHA). HPBL growing in these cultures were T cells as determined by E-rosetting (greater than 85%) and were positive for the OKT8 marker. The growth frequency (f) of HPBL in LD was f = 1/20-1/100. Such cells were induced with T cell mitogens (Con A or PHA) to release lymphokines into the supernatant. Statistical analysis of the data from the LD experiments showed that (a) the precursor cell frequency for IFN-gamma- and CSF-producing T cells was f = 1/63-1/151 and 1/89-1/217, respectively, and (b) most T cell clones released IFN-gamma and CSF simultaneously. In addition, individual T cell clones were shown to be capable of releasing different CSF types. In principle, this experimental system can be used to evaluate the precursor frequency, relationship and activity of normal or pathological human T cells performing any in vitro T cell function.

Bone Marrow Cells↗
PubMed1984

Cytolytic T cells recognize the two amino-terminal domains of H-2 K antigens in tandem in influenza A infected cells.

We have genetically engineered three alleles of the K locus of the major histocompatibility complex (MHC) of the mouse. These novel hybrid H-2K genes were introduced into mouse 1T 22-6 cells (H-2q), and their products were shown to be expressed on the cell surface. The hybrid H-2 K antigens were examined for their ability to function as restricting elements for cytotoxic T lymphocytes during influenza A infection. Both the alpha 1 and alpha 2 domains of the Kd antigen were required for T cell recognition. This implies an important role for "conformational determinants" on H-2 antigens acting as restricting elements. The cytoplasmic domain of the Kb antigen is not phenotypically important for recognition by T cells.

Amino Acid Sequence↗
PubMed1983

Macrophage-activating factors from different T cell clones induce distinct macrophage functions.

The data reported in this paper are the first demonstration that different T cell clones (PC-AKR-CI 96, clone 96; PK 7.1.2 E8, clone 7.1.2 E8) secrete different macrophage-activating factors (MAF) that induce distinct macrophage activities. Incubation of resident murine macrophages with MAF 7.1.2 E8 increased RNA, protein, and glycoprotein synthesis, hexosemonophosphate shunt (HMPS) activity, release of oxygen metabolites (O-2, H2O2), pinocytosis, phagocytosis, and tumor cytostasis, whereas no effect on prostaglandin E (PGE) release, schistosomula killing, and tumor cytolysis could be observed. In contrast, MAF 96 increased glycoprotein synthesis, HMPS activity, release of oxygen metabolites and PGE, schistosomula killing, and tumor cytostasis and cytolysis, whereas RNA and protein synthesis and pinocytosis were decreased and phagocytosis remained unaffected. Thus, MAF from both T cell clones share some macrophage-activating properties but differ in others. Most importantly, both MAF could be differentiated serologically by a rabbit anti-lymphokine antiserum that selectively inhibited MAF 96 but not MAF 7.1.2 E8 activity. At optimal concentrations, MAF 96 and 7.1.2 E8 were active in the absence of lipopolysaccharide (LPS) whereas LPS enhanced the activity of suboptimal doses of MAF 96 but not of MAF 7.1.2 E8. These data are discussed with respect to the possibility that the functional dichotomy of T cell clones might reflect different activities of normal T cell subpopulations.

Animals↗
PubMed1978

Specific adsorption of H-2-restricted cytotoxi T cells to macrophage monolayers.

These experiments tested whether Tc cells specific for foreign antigen (X) plus self H-2 adsorbed to macrophage monolayers displaying (a) X with allogeneic H-2; (B) self H-2 alone; (c) X plus self H-2. Specific adsorption occurred only in case (c), a result compatible with altered self and requiring further operational assumptions in dual recognition models.

Animals↗
PubMed1978

Cytotoxic T-cell responses show more restricted specificity for self than for non-self H-2D-coded antigens.

The specificity of recognition of H-2 antigens by various subsets of Tc cells was investigated with respect to the two separate molecules known to be coded in the H-2D(d) region (a) D which carries the private specificity H-2.4 and (b) D'which carries the public specificity H-2.28. BALB/c.H-2(db) mutant mice express D but not D' on their cell surfaces, whereas wild-type BALB/c mice express both D and D'. H-2 restricted Tc cells specific for viral-plus- H-2D(d)-coded antigens on infected self cells, or minor H-plus-H-2D(d)-coded antigens on H-2-compatible cells apparently recognize D, but do not detectably recognize D. In contrast, BALB/c-H-2(db) anti-BALB/c Tc cell responses do recognize D' (the only known antigen which is not shared by mutant and wild-type); furthermore, D' is also detectably recognized by a significant proportion of the Tc cells that respond in MLR to H-2D(d)-coded antigens. In these latter responses, D' was recognized separately from D, i.e., the response was not "H-2 restricted". These results indicate that H-2 restricted Tc cell responses to modified-self cells are more specific for self H-2D(d)-coded antigens then are allogeneic Tc cell responses directed at the same antigens, in that haplotype-unique (private) specificity recognition (of the D molecule) exclusively occurs only in the former, not the latter case. The implications of this specificity of H-2 restricted responses for possible processes of somatic selection of anti-self recognition structures on progenitor Tc cells are briefly discussed.

Animals↗
PubMed1977

Cytotoxic T-cell response to Ectromelia virus-infected cells. Different H-2 requirements for triggering precursor T-cell induction or lysis by effector T cells defined by the BALB/c-H-2db mutation.

The T(c)-cell response to ectromelia virus infection was studied in BALB/c-H-2(db) mice which carry a loss mutation in the H-2D region that results in the absence from cell surfaces of a molecule (D') bearing certain public H-2 specificities. When infected, these mice showed a poor response of T(c) cells that recognize H-2D(d) plus virus-specific determinants on infected macrophage targets, but gave a normal response to H-2K d plus virus-specific antigens. However, their own infected macrophages do display wild-type antigenic patterns involving virus and H-2D(d) since they were killed as efficiently as wild-type (BALB/c,H- 2(d))-infected cells by T(c) cells specific only for H-2D(d) plus viral antigens. When tested in vitro, infected BALB/c-H-2(db) cells stimulated a poor T(c)-cell response to H-2D plus virus-specific antigens, but stimulated a normal response (in comparison with infected BALB/c macrophages) to H-2K(d) plus viral antigens. Uninfected BALB/c-H-2(db) cells stimulated a normal T(c)-cell response to minor H antigens or trinitrophenyl in association with H-2D(d), thus suggesting that the defective response to infection may reside in a failure of the relevant H-2D(d) antigens of mutant cells to physically associate with viral antigens. Close association of viral and H-2D-coded molecules was also suggested by ability of specific anti-H-2K or -H-2D to partially block T(c)-cell-mediated lysis of infected targets. These results were interpreted to mean that H-2Dd-dependent, virus- immune T(c) cells recognized an antigenic pattern consisting of virus- specific and H-2D(d) determinants with the latter borne on an H-2D molecule carrying serologically-defined H-2D(d) private specificities. A second H-2D(d)-coded molecule (D') was not required for recognition and lysis by activated T(c) cells, but was apparently necessary for efficient stimulation of precursor T(c) cells, perhaps by promoting appropriate physical association of viral and H-2D(d) molecules.

Animals↗
PubMed1977

H-2 restriction of cell-mediated immunity to an intracellular bacterium: effector T cells are specific for Listeria antigen in association with H-21 region-coded self-markers.

The protective activity of anti-Listeria-immune T cells assayed in an adoptive transfer system in H-2 restricted. As shown in the present studies, the demonstration of the restriction is directly dependent on the dose and the relative protective activity of spleen cells. In addition, some H-2-unrestricted protection is conferred predominantly by other than immunoglobulin-negative spleen cells. Thus, the activity of Listeria-immune T cells appears to be 'absolutely' restricted and is in this respect comparable to in vivo T-cell-mediated anti-viral protection. The predominant genetic region of H-2 coding for the structures which are mainly involved in this restriction in T-cell immunity to this prototype intracellular bacterium is the I region. The specificity of Listeria-immune T cells is determined by the H-2 haplotype of the donor. Thus, F1 hybrids seem to possess at least two separable sets of T cells, each specific for one parental haplotype. As is true in the virus model, the results cannot distinguish between an altered-self or a dual recognition model of T-cell recognition to explain H-2 restriction. They are, however, compatible with the idea and I-coded cell surface structures may serve as receptors for cell-specific differentiation signals, which trigger direct or lymphokin-mediated activation of macrophages to manifest increased bactericidal capacity. The interesting parallels in self-marker recognition of T cells in the virus and intracellular bacterium systems, respectively, appear to be reasonably explained by the different types of signals transmitted by T cells to various target cells via the distinctly different self-markers employed (i.e., K or D vs I).

Animals↗
PubMed1977

In vitro primary induction of cytotoxic T cells against virus-infected syngeneic cells.

An in vitro method is described for primary induction of murine cytotoxic T cells against syngeneic cells infected with ectromelia or lymphocytic choriomeningitis (LCM) virus. Cytotoxicity was assayed by 51Cr release from macrophage or L929 target cells. Cytotoxic activity was sensitive to anti-theta and complement and was expressed only against target cells infected with the same virus and sharing H-2K or H-2D genes with the infected stimulator cells. The crucial factors in generating responses were mouse strain, responder: stimulator ratio, nature of infected stimulator cells, and presence of sufficient macrophages. C57BL/6 cells were less demanding than CBA/H and BALB/c cells. Under optimal conditions defined here, the in vitro response had similar kinetics and potency to the primary response in the spleen in vivo.

Animals↗
PubMed1977

Protective activity of secondary effector T cells generated in vitro against ectromelia virus infection in vivo.

The anti-viral activity of secondary effector cells generated in vitro against ectromelia virus infection was investigated. Depending upon the order of administration of cells and virus, 2 X 10(6) cells significantly reduce virus titres in recipient mice. Mice injected with lymphocytic choriomeningitis (LCM) virus are not protected by secondary effector cells against ectromelia virus infection and vice versa. The cells conferring anti-viral activity are sensitive to anti-theta and complement treatment, and must share H-2K or H-2D region genes with the recipients in order for significant reduction of virus titres to occur. The possibility of exploiting this approach in clinical medicine by using T cell-mediated mechanisms against certain viral infections is briefly discussed.

Animals↗
PubMed1976

A single genetic element in H-2K affects mouse T-cell antiviral function in poxvirus infection.

Cell transfer experiments using mice with recombinant H-2 haplotypes were used to map the H-2 regions which must be shared by ectromelia-immune T-cell donors and virus-infected recipients for transfer of virus clearance mechanisms in the spleen. K- or D-region genes were necessary and sufficient; I-region genes were not involved. The remainder of the mouse genome could be varied widely without impairing the efficacy of T-cell antiviral function, provided either a K or a D region was shared in the donor-receipient combination. A mutation in a single genetic element of the K region of the H-2 complex abolished the antiviral effect of immune T-cell transfer in a donor-recipient combination which shared the K end.

Animals↗