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H Hengartner

Publications and source records attributed to H Hengartner.

At least 271 records · Page 15Linked to original sources
PubMed1987

Characterization of virus-specific cytotoxic T cell clones from allogeneic bone marrow chimeras.

We established several H-2-restricted lymphocytic choriomeningitis virus (LCMV)-specific cytotoxic T cell clones from spleens of virus-primed C57BL/6 or C57BL/10 (H-2b) and B10.BR (H-2k) mice and from allogeneic C57BL/10----B10.BR and B10.BR----C57BL/10 bone marrow chimeras. Two T cell clones of H-2b origin and restricted to H-2b, 3 of H-2k origin and restricted to H-2k were compared with two clones each derived from the two types of chimeras. Their surface phenotype was found to be Lyt-2+, L3/T4- and KJ16-133+ (2 of 9). Clones from chimeras expressed bone marrow donor H-2 and are restricted to the recipient H-2. H-2k-restricted clones were all specific for Kk whereas all H-2b-restricted clones were specific for Db. These restriction specificities could be further defined by the blocking activity of various monoclonal anti-H-2 antibodies. Interestingly the anti-H-2Db antibodies blocked the restricted virus-specific killing activity of the clones derived B10.BR----C57BL/10 chimeras much more effectively than the activity of the clones derived from conventional H-2b mice. The various clones differed with respect to their fine specificity for LCMV strains. The 3 clones of conventional B10.BR origin only recognized LCMV-WE but not LCMV-Armstrong, Aggressive or Docile; H-2b-restricted conventional clones recognized target cells infected with all LCMV strains except LCMV-UBC-Docile; the T cell clones from the bone marrow chimeras recognized with one exception all LCMV strains tested.

Animals↗
PubMed1987

The T cell-specific serine proteinase TSP-1 is associated with cytoplasmic granules of cytolytic T lymphocytes.

This study describes the localization of the previously purified T cell-specific serine proteinase, termed TSP-1 (M. M. Simon et al., EMBO J. 1986. 5: 3267), within cytoplasmic granules of cytolytic T cell lines (CTLL). Subcellular fractionation of disintegrated CTLL (ruptured by nitrogen cavitation) was accomplished by Percoll density gradient centrifugation of cell lysates (postnuclear supernatant). Individual fractions were tested for proteinase activity on chromogenic peptide substrates and for the presence of TSP-1 by Western blot analysis. In addition, each fraction was assayed for cytolytic activity against sheep red blood cells (SRBC), for protein and for additional marker enzymes to assess the enrichment for cellular organells. All serine enzyme-type molecules including TSP-1 expressed by CTLL were identified by labeling cell lysates or gradient fractions with the serine proteinase-specific affinity ligand tritiated diisopropyl fluorophosphate [( 3H]DFP) in the presence or in the absence of class-specific or enzyme-specific proteinase inhibitors and subsequent sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The data demonstrate that the Percoll gradient fraction, which was shown by morphological examination in the electron microscope to be highly enriched for cytoplasmic granules, also contained greater than 80% of proteinase activity in addition to the granule-associated structures cytolysin and arylsulfatase. The identity of the granule-associated proteinase in two independent cell lines, CTLL HY3-Ag3 and CTLL 1.D.9, with the serine proteinase TSP-1 is indicated by its specificity for the chromogenic substrate H-D-Pro-Phe-Arg-p-nitroanilide, its sensitivity to class-specific as well as TSP-1-specific enzyme inhibitors and by its reactivity with a polyvalent TSP-1-specific rabbit antiserum. Both CTLL contain a [3H]DFP-labeled protein that migrates with a molecular mass of 60 kDa under nonreducing conditions and with 30 kDa under reducing conditions and which can be inactivated by the TSP-1-specific inhibitor H-D-Pro-Phe-Arg-chloromethylketone. CTLL HY3-Ag3 (a long-term culture CTLL with natural killer-like activity) but not CTLL 1.D.9 (an antigen-specific short-term cultured CTLL) express in addition a further [3H]DFP-binding protein which migrates with 27 kDa under nonreducing or reducing conditions. No substrate specificity was found for this molecule. The possible function of the granule-associated serine proteinase TSP-1 is discussed.

Amides↗
PubMed1987

Molecular analysis of the antigen receptor of virus-specific cytotoxic T cells and identification of a new V alpha family.

We have determined the primary structure of the alpha/beta-antigen receptor of a lymphocytic choriomeningitis virus (LCMV)-specific cytotoxic T cell clone (P14). The beta chain of the T cell receptor is composed of V beta 8.1, D beta and J beta 2.4 gene segments while the alpha chain uses a member of the V alpha 2 family and J alpha TA31. Southern blot analysis of a panel of six other independent LCMV-specific cytotoxic T cell clones did not reveal any preferential usage of the V alpha 2 or V beta 8 gene families in the cytotoxic LCMV response. Additionally, we have isolated and sequenced cDNA clones derived from the non-functionally rearranged alpha allele of P14. This transcript is composed of a unique V alpha gene segment which belongs to a new V alpha gene family.

Amino Acid Sequence↗
PubMed1987

Fine specificity and T-cell receptor beta-chain gene rearrangements of five H-2Db-specific cytotoxic T-cell clones.

A panel of cytotoxic T lymphocyte clones that recognize H-2b target cells has been established. Six different clones were distinguished according to the following criteria. First, the fine specificity of the clones was determined by testing proliferation and cytotoxicity on target cells of recombinant mice. Clone 221 recognized H-2Kb, and five other clones recognized H-2Db. Clone 433 distinguished itself from the other five Db-specific clones by cross-reacting with an antigen on H-2k cells. Second, the presence of an idiotypic determinant as defined by the 3F9 clone-specific monoclonal antibodies was investigated in cytotoxicity inhibition experiments. One of the Db-specific clones, 653, was inhibited by these antibodies and was therefore clearly different from the other Db-specific clones. The third criterion involved the rearrangement pattern of the DNA coding for the beta chain of the T-cell receptor. Southern blot analysis showed that each clone had a unique pattern. Interestingly, clone 653, which expresses the same idiotypic determinant as clone 3F9, had deleted the C beta 1 gene cluster, whereas this gene is functionally expressed in clone 3F9.

Animals↗
PubMed1987

T-cell antigen receptors with identical variable regions but different diversity and joining region gene segments have distinct specificities but cross-reactive idiotypes.

The T-cell antigen receptor alpha-chain genes of an alloreactive, H-2Db-specific cytotoxic T-cell clone (3F9) are described. This study and our work on the 3F9 beta-chain genes reveal that the variable region gene segments for the alpha and beta chains expressed in 3F9 are identical to the ones used by a chicken erythrocyte-specific, I-Ab-restricted helper T-cell clone (LB2). These two clones differ, however, in the diversity and joining portions of the alpha and beta chains of their T-cell receptor molecules. The analysis of 3F9 and LB2 with monoclonal antibodies specific for the 3F9 T-cell receptor shows that these two T-cell clones share the same idiotype; however, 3F9 and LB2 do not exhibit any antigen and/or major histocompatibility complex cross-reactivity. This suggests that the diversity and joining regions of the T-cell receptor may play a key role in antigen and/or major histocompatibility complex recognition.

Animals↗
PubMed1987

Antibodies against the two serotypes of vesicular stomatitis virus measured by enzyme-linked immunosorbent assay: immunodominance of serotype-specific determinants and induction of asymmetrically cross-reactive antibodies.

The serological relationship between the two vesicular stomatitis virus (VSV) strains Indiana (VSV-Ind) and New Jersey (VSV-NJ) were analyzed by using an enzyme-linked immunosorbent assay (ELISA). Immunoglobulin G responses, defined by their resistance to treatment with 2-mercaptoethanol, were assessed by ELISA by using sucrose gradient-purified VSV or purified VSV glycoproteins (G) as antigens. When low doses (10(6) PFU) of live VSV or 10(8) PFU of UV-inactivated virus were given intraperitoneally (i.p.), only non-cross-reactive antibody responses were observed in a primary immune response. However, when 10(6) PFU of live VSV were injected intravenously (i.v.), cross-reactive antibodies were generated; anti-VSV-NJ antibodies cross-reacted more against VSV-Ind than did anti-VSV-Ind antibodies against VSV-NJ. When 10(8) PFU of live VSV or UV-inactivated VSV mixed with complete Freund adjuvant was given i.p., high levels of cross-reactive antibodies detectable by ELISA were induced in primary and secondary responses. When purified G protein was used instead of purified whole virus in the ELISA, the cross-reactivity was found to be asymmetrical after immunization with live VSV given i.v. but not after i.p. inoculation; anti-VSV-NJ sera bound almost equally well to VSV-Ind G protein, whereas anti-VSV-Ind sera bound virtually exclusively to the G protein of the homologous serotype. The data suggest that immunization with VSV given i.p. results in a more specific, i.e., less cross-reactive, response than that either after i.v. infection or after the virus antigen is made available in great amounts or if it persists for prolonged periods when given i.p. together with complete Freund adjuvant. The unique determinants were immunodominant because they induced antibodies preferentially, whereas partially shared determinants induced antibody responses asymmetrically, more slowly, and with lower titers. Interestingly, the asymmetric cross-reactivity of anti-VSV antibodies, as measured by ELISA, against purified VSV G was opposite that observed for cytotoxic T cells.

Animals↗
PubMed1987

[Liposomes as carriers of lipophilic cytosine arabinoside and fluorodeoxyuridine derivatives. Their cytostatic effect and possibilities of tumor cell specific therapy].

A method of preparation for large volumes of sterile, homogenous bilayer liposomes as carriers of lipophilic cytostatic prodrugs is described. Liposomes in the size range of 60 to 120 nanometers are produced through the dialysis of lipid/prodrug/detergent micelles by means of a capillary dialysis system. The cytostatic effect of cytosine arabinoside (ara-C) prodrug liposomes against L1210 leukemia showed to be superior to free ara-C treatment in respect to drug dosage and treatment schedule. Fluorodeoxyuridine (FUdR) prodrug-liposomes were active against various solid tumors, although with less pronounced effects, but at 20-60 times lower drug concentrations as compared to free FUdR. To further improve the cytostatic effect of such prodrug-containing liposomes, methods for the linkage of tumor-cell-specific antibodies to the liposomes are discussed. The targeted delivery of cytostatic drugs by such means might improve their antitumor effects and reduce the untoward toxic side-effects.

Animals↗
PubMed1986

Characterization of an Lyt-2+ alloreactive cytotoxic T cell clone specific for H-2Db that cross-reacts with I-Ek.

An alloreactive cytotoxic T cell clone (433) possessing the L3T4-, Lyt-2+ phenotype is described that shows a double specificity. It has been derived from unprimed BALB/c (H-2d) spleen cells by repetitive in vitro restimulation with C57BL/6(H-2b) cells. The specificity of clone 433 was determined in cytotoxicity and proliferation experiments. One specificity was for the class I antigen H-2Db and the second was for the class II antigen I-Ek. Inhibition of cytotoxicity with monoclonal antibodies confirmed these results. Cold target competition experiments demonstrated that the two specificities were mediated by the same cell population. Anti-Lyt-2 antibodies inhibited only the H-2Db- but not the I-Ek-specific lysis, suggesting a higher affinity of the antigen receptor for I-Ek than for Db. To our knowledge, this is the first description of a T cell clone that is specific for a class I antigen and cross-reacts heteroclitically with a class II antigen.

Animals↗
PubMed1986

T cell-mediated hepatitis in mice infected with lymphocytic choriomeningitis virus. Liver cell destruction by H-2 class I-restricted virus-specific cytotoxic T cells as a physiological correlate of the 51Cr-release assay?

A model for immunologically T cell-mediated hepatitis was established in mice infected with lymphocytic choriomeningitis virus (LCMV). The severity of hepatitis was monitored histologically and by determination of changes in serum levels of the enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH), and alkaline phosphatase (AP). Kinetics of histological disease manifestations, increases of liver enzyme levels in the serum, and cytotoxic T cell activities in livers and spleens all correlated and were dependent upon several parameters: LCMV-isolate; LCMV-WE caused extensive hepatitis, LCMV-Armstrong virtually none. Virus dose. Route of infection; i.v. or i.p. infection caused hepatitis, whereas infection into the footpad did not. The general genetic background of the murine host; of the strains tested, Swiss mice and A-strain mice were more susceptible than C57BL or CBA mice; BALB/c and DBA/2 mice were least susceptible. The degree of immunocompetence of the murine host; T cell deficient nu/nu mice never developed hepatitis, whereas nu/+ or +/+ mice always did. B cell-depleted anti-IgM-treated mice developed immune-mediated hepatitis comparably or even more extensively than control mice. Local cytotoxic T cell activity; mononuclear cells isolated from livers during the period of overt hepatitis were two to five times more active than equal numbers of spleen cells. Adoptive transfer of nylon wool-nonadherent anti-Thy-1.2 and anti-Lyt-2 plus C-sensitive, anti-L3T4 plus C-resistant lymphocytes into irradiated mice preinfected with LCMV-WE caused a rapid time- and dose-dependent linear increase of serum enzyme levels. This increase was caused by adoptive transfer of lymphocytes if immune cell donors and recipient mice shared class I, but not when they shared class II histocompatibility antigens. The donor cell dose-dependent increase of these enzymes was first measurable 6-18 h after transfer with 2 X 10(8) cells or 3 X 10(6) cells, respectively. The time-dependent increase caused by the adoptive transfer of 1-2 X 10(8) cells was strictly linear during a period of up to 25-40 h. These results indicate single-hit kinetics of liver cell death and suggest that effector T cells destroy infected liver cells via direct contact rather than via soluble toxic mediators. The results may represent the best in vivo correlate of the in vitro 51Cr-release assay that has been analyzed so far, and strongly support the view that antiviral cytotoxic T cells are directly cytolytic in vivo.(ABSTRACT TRUNCATED AT 400 WORDS)

Alanine Transaminase↗
PubMed1986

Effect of rabbit anti-asialo GM1 treatment in vivo or with anti-asialo GM1 plus complement in vitro on cytotoxic T cell activities.

The susceptibility of cytotoxic effector lymphocytes and their induction to in vivo or in vitro treatment with rabbit anti-neutral glycolipid ganglio-N-tetraosylceramide (anti-ASGM1) antiserum was investigated. Intravenous injection of anti-ASGM1 antiserum eliminated measurable natural killer (NK) cell activity in spleen cells of mice infected for 5 days with Vaccinia virus, or for 8 days with lymphocytic choriomeningitis virus (LCMV) if injected 24 hr prior to testing. In addition, this treatment lowered measurable virus-specific cytotoxic T cell activity by 60 to 95%. Virus-specific cytotoxic T cell and NK cell activity generated during a primary infection in vivo was also sensitive to treatment in vitro with anti-ASGM1 antiserum (1/300 to 1/600 dilution) plus rabbit complement at a dilution of 1/15 (20 to 50% cell death, more than 30-fold decrease of cytotoxic activity); in vitro treatment with rabbit complement alone often enhanced NK and cytotoxic T cell activity slightly. In vivo treatment with anti-ASGM1 before primary immunization decreased generation of primary CTL only if high doses of anti-ASGM1 antiserum were injected twice. Antiviral T cells generated during secondary stimulation in vitro and alloreactive cytotoxic T cells from a mixed lymphocyte culture were resistant to treatment in vitro with anti-ASGM1 plus complement at the end of the culture period. Treatment in vitro of in vivo-primed responder spleen cells with anti-ASGM1 plus complement before their addition to a secondary restimulation culture resulted in complete inhibition of a secondary antiviral cytotoxic T cell response. In vivo treatment with anti-ASGM1 24 hr before their spleen cells were harvested and restimulated in vitro significantly reduced the virus-specific T cell activity of mice that had been immunized with virus several weeks previously. A cloned T cell line exclusively exerting NK-like activity was resistant, and two cloned virus-specific cytotoxic T cell lines were susceptible to treatment with anti-ASGM1 plus complement in vitro. These results caution the general use of rabbit anti-ASGM1 as a marker to distinguish NK from CTL cells; they indicate a possible relationship between NK and CTL cells and suggest that in vitro culture of lymphocytes may alter or select the cell surface expression or availability of the ASGM1 marker(s).

Animals↗
PubMed1986

T cell-specific gamma genes in C57BL/10 mice. Sequence and expression of new constant and variable region genes.

The T cell-specific gamma genes in C57BL/10 (B10) mice have been analyzed. Based on the cDNA sequences of these genes from antigen-specific MHC-restricted cytotoxic T cells, we found that the repertoire of these genes is not as limited as previously postulated (8). T cells from the B10 mice express an identical copy of V gamma J gamma C gamma (V gamma 10.8A-JC gamma 10.5) transcript previously found in T cells of BALB/c mice. In addition, a potentially functional mRNA using V gamma 10.8B and newly identified J gamma and C gamma gene segments were found. The new J gamma C gamma (JC gamma 10.8) is located 5' to the inverted V gamma 10.8B in the germline DNA of both B10 and BALB/c mice. This new C gamma is only 77 and 66% homologous to the C gamma 10.5 at the nucleotide and deduced protein sequences, respectively, thus making it a potential isotype of the C gamma genes reported previously. The V gamma 5.7, J gamma 2.3 gene segments and pseudogene C gamma 7.5 found in the germline DNA of BALB/c mice are absent in B10 mice. The loss of this gamma chain pseudogene in the B10 mouse strain, and the retention of all potentially functional V gamma, J gamma, and C gamma genes with highly conserved coding sequences supports the importance of these genes.

Amino Acid Sequence↗
PubMed1986

Purification and characterization of a cytolytic pore-forming protein from granules of cloned lymphocytes with natural killer activity.

A cytolytic pore-forming protein (PFP, perforin) was purified from isolated granules of cloned NK-like cytolytic cells, which showed an apparent Mr of 70-75 kd (reduced) and 62-66 kd (nonreduced). Cytolysis produced by this protein occurred only in the presence of Ca2+ and was accompanied by the formation of membrane lesions of 160 A diameter. The purified protein depolarized cells and made lipid vesicles leaky to monovalent and divalent ions. This protein formed large, voltage insensitive and nonselective ion channels in planar bilayers that remained preferentially in the open state. The channels were heterogeneous in size distribution averaging 400 pS/U in 0.1 M NaCl. The membrane lesions formed by PFP were morphologically and functionally similar to those formed by intact NK-like cells and their granules. This PFP could be released from granules during cell killing, followed by its polymerization on target membranes to form large transmembrane pores.

Calcium↗
PubMed1986

Treatment of murine L1210 lymphoid leukemia and melanoma B16 with lipophilic cytosine arabinoside prodrugs incorporated into unilamellar liposomes.

Lipophilic prodrugs of I-beta-D-arabinofuranosyl cytosine (Ara-C), namely N4- and 5'-oleyl-I-beta-D-arabinofuranosyl cytosine (N4-oleyl-ara-C, 5'-oleyl-ara-C) and N4-palmitoyl-I-beta-D-arabinofuranosyl cytosine (N4-palm-ara-C) were incorporated into liposomes of various lipid compositions. The phospholipid vesicles were prepared by controlled dialysis of lipid/prodrug/detergent micelles yielding homogeneous and stable unilamellar liposomes. The liposome size ranged from 70 to 120 nm depending on the lipid composition and the amounts of prodrug incorporated. Depending on the total amount of micellized Ara-C prodrugs, a maximal incorporation rate of 250 micrograms prodrug per mg egg phosphatidylcholine was achieved. The incorporation efficiency was in the range of 85 to 97%. The in vivo antitumor activity of the liposome preparations against L1210 lymphoid leukemia was clearly superior by factors of 2-8 depending on the therapy schedule and route of drug application. The treatment of melanoma B16 with free Ara-C as well as with the prodrug-liposomes exhibit rather weak antitumor activity. Drug application by means of prodrug-liposomes yields equal or higher tumor-inhibitory effects at drug concentrations which were 2-4 times lower than those of free Ara-C. Although drug tolerance and myelosuppression studies with Swiss albino mice revealed that the prodrug-liposomes were 5-10 times more toxic than free Ara-C, a substantial improvement of efficiency could be observed. The incorporation of the ara-C prodrugs into liposomes provides protection against fast degradation and systemic elimination which might be an explanation for the improved antitumor effect of these preparations.

Animals↗
PubMed1986

A monoclonal antibody against altered LFA-1 induces proliferation and lymphokine release of cloned T cells.

A murine monoclonal antibody (I-17, IgM) has the following functional effects on murine long-term T cell clones: inhibition of cell-mediated lysis, induction of proliferation, release of lymphokines and change of the cell morphology. The determinant detected by I-17 is expressed on long-term T lines but not on thymocytes, lymph node cells and spleen cells. I-17 precipitated proteins with apparent molecular mass of 220 kDa, 170 kDa, 150 kDa and 100 kDa. Biochemical studies indicate that the determinant recognized by I-17 is tunicamycin sensitive and that I-17 binds to the alpha chain of the lymphocyte function-associated antigen (LFA-1).

Animals↗
PubMed1986

Induction or prevention of immunopathological disease by cloned cytotoxic T cell lines specific for lymphocytic choriomeningitis virus.

Cloned lymphocytic choriomeningitis virus (LCMV)-specific cytotoxic T lymphocyte (CTL) lines were prepared from spleens of 129/J (H-2b) mice immunized 7-9 months earlier with LCMV (UBC strain), or of C57BL/10J (H-2b) mice immunized 4 to 5 weeks earlier with LCMV (Armstrong strain). One uncloned and 3 cloned cytotoxic T cell lines were assessed for their respective abilities to produce, or protect against, fatal disease upon transfer to appropriate recipients or to induce specific footpad-swelling reaction. The effects of all lines were essentially identical. In recipient mice acutely infected with LCMV and immunosuppressed either by irradiation (750-990 rds) or treatment with cyclophosphamide, cloned T cells administered intracerebrally (i.c.) caused a convulsive disease and death within 1-4 days. No disease was produced when the same CTL were transferred to uninfected recipients or when they had been frozen and thawed prior to transfer to infected recipients. When admixed with 500 plaque-forming units of LCMV and transferred i.c. to immunocompetent H-2b mice, the T cell clones prevented overt disease. Allogeneic (H-2k) recipients of this same admixture all developed typical LCM disease as did H-2b recipients of the admixture after T cells had been frozen and thawed. Inoculation of cloned CTL into preinfected footpads induced a specific footpad-swelling reaction, which reached maximum levels after about 36 h. Irradiated and infected recipients of cloned LCMV-specific T cells showed the footpad-swelling reaction only when they had been reconstituted with bone marrow cells. In contrast, cloned T cells induced LCM disease in i.c. infected and irradiated mice independent of bone marrow reconstitution. These findings indicate that both fatal LCMV-induced neurologic disease and protection against it are mediated directly by virus-specific CTL.

Animals↗
PubMed1986

Primary antibody responses to a well-defined and unique hapten are not enhanced by preimmunization with carrier: analysis in a viral model.

We used a viral model to reexamine classical experiments showing that mice previously primed with a "carrier" molecule alone and then challenged with the carrier-hapten conjugate exhibited an enhanced antihapten antibody response. Mice were primed with live or UV-inactivated vesicular stomatitis virus (VSV) Indiana (Ind) serotype with or without complete Freund's adjuvant. After challenge with VSV New Jersey (NJ), these mice developed a secondary-type IgG response, measured by antibody binding in an ELISA, against both VSV-Ind and VSV-NJ. The same result was found for the reciprocal experiments where mice were primed with VSV-NJ. Similarly, when mice were primed with live VSV, UV-inactivated VSV, or purified VSV glycoprotein G of Ind or NJ serotype and later were challenged with dinitrophenyl (N2ph)-conjugated, UV-inactivated VSV or with N2ph-conjugated G protein of either serotype, they exhibited a secondary-type anti-N2ph antibody response as demonstrated by the binding of IgG to dinitrophenylated bovine serum albumin measured by ELISA. In contrast, when neutralizing antibody responses were monitored, VSV-Ind-primed mice challenged with VSV-NJ developed a strictly primary type of anti-VSV-NJ response and vice versa. We conclude that preexistent helper T cells specific for shared carrier determinants do not improve virgin B-cell responses specific for "new," unique determinants that are the target for the biologically relevant neutralizing antibodies. These findings suggest that priming of B cells rather than of helper T cells may be of importance to induce protective immunity mediated by antibodies.

Animals↗