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J M Katz

Publications and source records attributed to J M Katz.

At least 19 recordsLinked to original sources
PubMed1995

Protection of mice against influenza A virus challenge by vaccination with baculovirus-expressed M2 protein.

We have investigated the potential of the conserved transmembrane M2 protein of influenza A/Ann Arbor/6/60 virus, expressed by a baculovirus recombinant, to induce protective immunity in BALB/c mice. Vaccination of mice with M2 shortened the duration of virus shedding and protected mice from a lethal infection with A/Ann Arbor/6/60 virus but not B/Ann Arbor/1/55 virus, suggesting that the protection was mediated by an M2-specific mechanism. Serum antibodies were detected which reacted with synthetic peptides defining three antigenic determinants located on both the external N- and internal C-termini of the M2 protein. Furthermore, vaccination with M2 protected mice from death following a lethal challenge with the heterologous A/Hong Kong/68 (H3N2) virus. These results demonstrate the potential to elicit heterosubtypic immunity to type A influenza viruses through vaccination with a conserved transmembrane protein.

Amino Acid Sequence↗
PubMed1994

Codominant mixtures of viruses in reference strains of influenza virus due to host cell variation.

Influenza viruses grown in chicken eggs may comprise mixtures of variants, creating problems in establishing international reference strains and in preparing high growth reassortants. We therefore analyzed representative reference strains of H3N2 viruses from 1987 to 1989 by direct sequencing of HA1. Three of seven reference strains had different nucleotides at the same position in nucleotide gels, indicating the presence of codominant mixtures. These nucleotide duplications occurred at residues previously shown to code for amino acids associated with egg adaptation (156, 186, and 193 of HA1). Cloning of these viruses in chicken eggs permitted separation of the mixtures, and the majority of these cloned viruses could be distinguished with monoclonal antibodies. The remaining four reference strains were homogeneous and contained one of the two amino acids usually found at these residues in HA1 (e.g., 145 Glu or Lys, 186 Ser or Ile). Analysis of epidemic H3N2 isolates, for which mammalian cell and egg isolates are available for sequence analysis from the same patient, confirmed that multiple nucleotide changes can occur at residues associated with egg adaptation. When reference or epidemic strains containing codominant mixtures were passaged in eggs one to five times, one of the codominant strains usually became dominant. Similar results were obtained with Madin Darby Canine kidney (MDCK) cells, although the dominant virus usually differed from that in eggs. Attempts to reselect an influenza virus possessing sequence changes in HA1 characteristic of mammalian cells or the original human isolate (i.e., 156 Glu, 158 Glu, 186 Ser) by multiple passages in MDCK cells were not successful, but evidence was obtained that MDCK cells can provide a selective growth advantage. Thus, variants that are dominant in eggs are not necessarily dominant in MDCK cells. To preserve the original genotype of viruses used as reference strains, we recommend the following procedure: (i) cloning in chicken eggs of the candidate virus at a very early passage, (ii) selection and analysis of multiple clones with the same ferret polyclonal and/or monoclonal antibodies used in the initial screening, and (iii) selection of the isolate whose hemagglutinin molecule most closely resembles the clinical isolate.

Animals↗
PubMed1994

Analysis of the primary T-cell response to Sendai virus infection in C57BL/6 mice: CD4+ T-cell recognition is directed predominantly to the hemagglutinin-neuraminidase glycoprotein.

Sendai virus infection of C57BL/6 mice elicits a strong CD4+ and CD8+ T-cell response in the respiratory tract. To investigate the specificity of the CD4+ T-cell response, a panel of hybridomas was generated from cells recovered from the respiratory tracts of infected mice. Using vaccinia virus recombinants expressing individual Sendai virus proteins, we found that the majority of these hybridomas (34 of 37) were specific for the hemagglutinin-neuraminidase (HN) glycoprotein. The hybridomas were then analyzed for reactivity to a set of overlapping peptides spanning the entire length of the hemagglutinin-neuraminidase glycoprotein. At least five H-2 I-Ab-restricted epitopes were defined in HN. The strong bias toward recognition of class II epitopes derived from a single viral protein contrasts with T-cell recognition of epitopes of several proteins in influenza A virus as found previously by others.

Amino Acid Sequence↗
PubMed1993

Influence of host cell-mediated variation on the international surveillance of influenza A (H3N2) viruses.

Growth of clinical specimens of influenza viruses in eggs can result in the selection of antigenic variants distinct from corresponding viruses grown in mammalian tissue culture. To evaluate the contribution of host cell selection on the antigenic diversity of human influenza isolates, as seen in annual surveillance studies, viruses grown in embryonated eggs were compared by antigenic and genetic analyses with their mammalian tissue culture-grown counterparts. Clinical specimens were gathered from around the world from late 1987 to 1990 and the antigenicity of isolated viruses was assessed by hemagglutination-inhibition assays using immune ferret sera as is currently performed for routine surveillance and the selection of vaccine strains. In addition, viruses were assessed using a panel of anti-H3 HA monoclonal antibodies. The extent of antigenic variation exhibited by the egg-grown strains was far greater than the relative antigenic homogeneity of the tissue culture-grown viruses. Nucleotide sequence analysis of HA1 gene PCR products of 28 MDCK cell and egg derived pairs allowed identification of amino acid substitutions responsible for the antigenic differences observed and the adaptation to growth in eggs. Among these substitutions was a change at amino acid position 186 of HA1 (Ser in tissue culture viruses and lle in egg-grown viruses) which was observed at relatively high frequency. Egg- and MDCK-grown pairs with this single amino acid difference were classified into distinct antigenic groups by ferret sera raised to WHO reference viruses. Given the additional antigenic diversity observed among egg-grown strains, considerable care should be taken in the selection of reference and vaccine strains grown in eggs. Rapid sequence comparisons of MDCK- and egg-grown viruses allow identification of variants arising through egg selection and will prove to be a useful adjunct to antigenic surveillance for the selection of reference and vaccine strains.

Africa↗
PubMed1992

Delayed clearance of Sendai virus in mice lacking class I MHC-restricted CD8+ T cells.

The role and interdependence of CD8+ and CD4+ alpha beta-T cells in the acute response after respiratory infection with the murine parainfluenza type 1 virus, Sendai virus, has been analyzed for H-2b mice. Enrichment of CD8+ virus-specific CTL effectors in the lungs of immunologically intact C57BL/6 animals coincided with the clearance of the virus from this site by day 10 after infection. Removal of the CD4+ T cells by in vivo mAb treatment did not affect appreciably either the recruitment of CD8+ T cells to the infected lung, or their development into virus-specific cytotoxic effectors. In contrast, depletion of the CD8+ subset delayed virus clearance, although most mice survived the infection. Transgenic H-2b F3 mice homozygous (-/-) for a beta 2 microglobulin (beta 2-m) gene disruption, which lack both class I MHC glycoproteins and mature CD8+ alpha beta-T cells, showed a comparable, delayed clearance of Sendai virus from the lung. Virus-specific, class II MHC-restricted CTL were demonstrated in both freshly isolated bronchoalveolar lavage populations and cultured lymph node and spleen tissue from the beta 2-m (-/-) transgenics. Treatment of the beta 2-m (-/-) mice with the mAb to CD4 led to delayed virus clearance and death, which was also the case for normal mice that were depleted simultaneously of the CD4+ and CD8+ subsets. These results indicate that, although classical class I MHC-restricted CD8+ cytotoxic T cells normally play a dominant role in the recovery of mice acutely infected with Sendai virus, alternative mechanisms involving CD4+ T cells exist and can compensate, in time, for the loss of CD8+ T cell function.

Animals↗
PubMed1992

Extent of gamma delta T cell involvement in the pneumonia caused by Sendai virus.

The prevalence of gamma delta T cells in bronchoalveolar lavage (BAL) populations recovered from the respiratory tract of young, adult C57BL/6J mice infected intranasally (i.n.) with Sendai virus has been assessed by FACS-phenotyping, and by probing cytocentrifuge preparations for expression of TCR gamma mRNA. The surface gamma delta TCR+ set comprised from 5 to 20% of the inflammatory lymphocytes in sequential samples taken throughout the course of this nonfatal viral pneumonia. The BAL population also contained numerous cells expressing mRNA for C gamma 1/2 and C gamma 4; the C-regions were utilized for productive TCR gene rearrangement. Sorting the lymphocytes from the BAL established that greater than 90% of both the TCR gamma and TCR beta mRNA partitioned to cells with the appropriate surface TCR phenotype, while less than 7% of the TCR mRNA+ cells in the total inflammatory exudate were phagocytes that engulfed latex particles. Both the frequency and the total numbers of the gamma delta TCR+ and TCR gamma mRNA+ cells were increased in mice depleted of alpha beta T cells by in vivo treatment with mAbs to CD4 and CD8, indicating that the CD4+ and CD8+ alpha beta and CD4-8- gamma delta T cell subsets may operate independently in this virus disease. The C gamma 1/2 mRNA phenotype predominated throughout the course of the active infection, with a transition to maximal prevalence of the C gamma 4 mRNA+ set occurring very late (Day 20) in the resolving inflammatory process. Large numbers of macrophages expressing mRNA (greater than 50%) for a mammalian 65-kDa heat shock protein (hsp65), a possible target for some of the gamma delta T cells, were present early (Days 5-7) and remained at lower levels (less than 20%) thereafter. These hsp65 mRNA+ macrophages were much less apparent in BAL populations from mice depleted concurrently of the CD4+ and CD8+ T cell subsets, indicating that exposure to Sendai virus alone is not the major factor inducing the transcription of this endogenous gene. These experiments thus establish that gamma delta T cells are a minority of the infiltrating lymphocytes in Sendai virus pneumonia and provide new insights into the spectrum of hsp65 mRNA and TCR gamma mRNA expression during an inflammatory process.

Animals↗
PubMed1992

Amino acid sequence identity between the HA1 of influenza A (H3N2) viruses grown in mammalian and primary chick kidney cells.

Primary isolation of type A influenza (H3N2) virus in mammalian Madin Darby canine kidney (MDCK) cells results in a virus with haemagglutinin (HA) identical to that of the virus replicating in the infected individual, whereas similar isolation of virus in the embryonated egg results in the selection of variants with amino acid substitutions in the globular head region of the HA molecule. To determine whether other mammalian and avian host cells routinely used in laboratory isolation of influenza viruses also impose a selective pressure on the replicating virus population, the HA of viruses isolated in several different primary or continuous mammalian cells or avian cells has been characterized. The HAs of H3N2 viruses isolated in monkey kidney LLC-MK2 and primary guinea-pig kidney cell culture were antigenically identical to MDCK cell-grown virus isolated from the same patient. The deduced amino acid sequence over the region of HA1 encoding residues implicated in host cell-mediated sequence variation revealed that the HA sequences of viruses isolated and passaged in these mammalian cell types, and in a human lung continuous cell line (MRC-5), were identical to that of the virus present in the infected individual. In addition, isolation of virus in avian primary chick kidney (CK) cells yielded a predominant virus with HA identical to that of mammalian cell-grown virus and the virus present in the original clinical material. However, passage of CK cell-grown virus in chicken embryos (eggs) resulted in the predominance of viruses with amino acid substitutions in HA, a minority of which resulted in antigenic variation. Since CK cell culture is used in the development of live attenuated influenza vaccines, the sequence identity between CK cell-grown virus and the virus present in the infected individual is reassuring. Nevertheless, subsequent passage of virus strains in eggs, necessary for vaccine production, must be monitored closely.

Amino Acid Sequence↗
PubMed1992

Application of Directigen FLU-A for the detection of influenza A virus in human and nonhuman specimens.

Directigen FLU-A, a new enzyme immunoassay membrane test, rapidly detects influenza A virus antigen in specimens from patients. Nasopharyngeal washes and pharyngeal gargles were used to determine the effectiveness of the assay as applied to different types of routinely collected clinical samples. All specimens had been previously shown to contain influenza A virus by virus isolation in tissue culture. Directigen FLU-A was 90% sensitive (95% confidence interval, 56 to 99.7%) with nasopharyngeal washes but only 39% sensitive (95% confidence interval, 17 to 64%) with pharyngeal gargles (P = 0.018) when used with samples containing similar amounts of infectious virus (50% tissue culture infective dose, 1.0 to 4.5). The intensity of the positive reaction with Directigen FLU-A did not correlate with the amount of virus in the specimens. Directigen FLU-A was found to detect cell-associated antigen more readily than free virus; only 20 infected cells were required to identify cell-associated influenza A virus antigen, whereas the limit of detection for free virus was 1.63 x 10(3) infectious virus particles. These findings suggest that Directigen FLU-A detects the cell-associated antigen present in clinical specimens rather than free virus. In addition, Directigen FLU-A detected avian and swine influenza A viruses in both cloacal swabs (75% sensitivity) and swine lung homogenates (86% sensitivity), indicating its potential usefulness in the surveillance of nonhuman influenza A viruses.

Animals↗
PubMed1990

Direct sequencing of the HA gene of influenza (H3N2) virus in original clinical samples reveals sequence identity with mammalian cell-grown virus.

When influenza (H3N2) viruses from infected individuals are grown in embryonated chicken eggs, viruses are isolated which differ antigenically and structurally from viruses grown in mammalian Madin-Darby canine kidney (MDCK) cell culture [G.C. Schild, J.S. Oxford, J.C. de Jong, and R.G. Webster, Nature (London) 303:706-709, 1983]. To determine which of these viruses is most representative of virus replicating in the infected individual, a region of the HA gene of virus present in original clinical samples was amplified by using the polymerase chain reaction and sequenced directly. Comparison of 170 amino acid residues of HA1 flanking and containing the receptor-binding site and antigenic sites indicated that over this region, the HA of virus replicating in the infected individual was identical to that of virus after growth in MDCK cells and was distinct from the HA of viruses grown in eggs. Therefore, cultivation of human influenza H3N2 virus in mammalian MDCK cells results in a virus similar to the predominant population of virus found in the infected individual.

Amino Acid Sequence↗
PubMed1989

Extensive heterogeneity in the hemagglutinin of egg-grown influenza viruses from different patients.

We establish that the cultivation of influenza (H3N2) virus from any infected individual in chicken embryos (eggs) can result in the isolation of viruses with antigenic and/or structural heterogeneity in the hemagglutinin (HA) molecule. This variability contrasted sharply with the apparent lack of antigenic alterations in the HA of influenza viruses isolated from patients in Madin Darby canine kidney (MDCK) cells. The most common subpopulation of egg-grown influenza viruses had the same phenotype as MDCK cell-grown virus and may best represent the virus circulating in humans. It should be considered the optimal strain for use in vaccine and epidemiologic studies.

Amino Acid Sequence↗
PubMed1989

Efficacy of inactivated influenza A virus (H3N2) vaccines grown in mammalian cells or embryonated eggs.

Influenza virus (H3N2) host cell variants isolated from a single infected individual were compared for their protective efficacies when used as formalin-inactivated purified whole virus vaccines in ferrets. A/Mem/12/85 virus grown in embryonated chicken eggs (egg-grown), which differs from A/Mem/12/85 grown in mammalian Madin-Darby canine kidney cells (MDCK-grown) by a single amino acid substitution in the hemagglutinin molecule, was shown to be distinguishable by immune ferret serum. Ferrets were immunized intramuscularly with intact inactivated MDCK- or egg-grown virus and were subsequently challenged with infectious virus grown in either host cell type. MDCK-grown-virus vaccine induced higher mean serum hemagglutination-inhibiting (HAI) and neutralizing antibody titers than did egg-grown-virus vaccine and induced superior protection of ferrets against subsequent challenge with infectious virus grown in either host cell type. These results suggest that human influenza viruses that are antigenically and structurally similar to viruses grown in mammalian cells may be more efficacious as vaccines than some variants selected in eggs.

Animals↗
PubMed1988

Aminobisphosphonate inhibition of interleukin-1-induced bone resorption in mouse calvariae.

Interleukin-1 (IL-1) is probably an important lymphokine mediator of inflammation and bone resorption. IL-1 derived from mononuclear cells, a melanoma cell line (MM96 cells), and recombinant human IL-1 (rHuIL-1 beta) increased in vitro bone resorption, as measured by the release of 45Ca from cultured mouse calvariae. The 50% maximum active resorption was observed with 0.125 ng/ml or approximately 10(-11) M rHuIL-1 beta. The resorptive action of IL-1 was not entirely dependent on prostaglandin mediation, since its effect was evident when prostaglandin synthesis was inhibited in the cultures by indomethacin. IL-1-induced resorption has been shown to be inhibited by 10(-5) M 3-amino-1-hydroxypropylidene-1-1-bisphosphonate (APD). This inhibition was partially reversed by increasing doses of IL-1. In vitro toxicity studies showed that at concentrations of 10(-4) M, APD inhibited the growth of cultured MM96, murine myelomonocytic P388D1, and rat osteosarcoma UMR 106 cells, but not other mast and lymphoid cell lines. These in vitro observations may have relevance to the use of APD in bone and joint diseases in which inflammation and bone resorption are prominent.

Animals↗
PubMed1988

Intravenous meperidine for control of shivering during caesarean section under epidural anaesthesia.

To determine the efficacy of meperidine in controlling shivering during epidural anaesthesia for Caesarean section, forty-six parturients were studied. After delivery of the infant, shivering patients received either a single dose of intravenous meperidine 50 mg, or saline in a randomized double-blind fashion. Shivering was classified on a scale of 0 to 3 (grade 0 = none, grade 3 = severe shivering that was distressing to the patient and interfered with monitoring). Shivering and other variables were recorded at epidural placement, skin incision, delivery, and 2, 5, 15, 30 and 60 minutes following injection. Administration of meperidine resulted in a significant decrease in both the overall incidence of shivering (87 to 35 per cent, p less than 0.01) and severity of shivering (grade 3:57 to 0 per cent, p less than 0.01), compared with saline (incidence: 87 to 83 per cent, grade 3:57 per cent, no change). This effect was apparent within two minutes of drug injection and persisted throughout the study period. There were no differences in vital signs, oxygen saturation or temperature between groups. The incidence of nausea was similar, although patients receiving meperidine were more drowsy at two and five minutes following injection (p less than 0.01) compared with patients in the saline group. There were no differences in level of consciousness at the later intervals. The mechanism of action of meperidine on shivering remains to be elucidated.

Adult↗
PubMed1988

Antigenic and structural characterization of multiple subpopulations of H3N2 influenza virus from an individual.

Influenza viruses grown in embryonated chicken eggs frequently possess antigenically distinguishable hemagglutinin (HA) compared to virus from the same source grown in mammalian cell culture. To further investigate the extent of variation among viruses from an individual, viruses were isolated from throat washes collected over a 48-hr period during infection with influenza virus designated A/Mem/6/86 (H3N2). Viruses were isolated from limit dilutions in eggs and mammalian Madin-Darby canine kidney (MDCK) cells and the antigenic, structural, and receptor-binding properties of these viruses were determined. Viruses which could be isolated in MDCK cells were present at 10- to 100-fold higher frequency in the original sample than viruses which could be isolated in eggs. The HA of virus clones isolated in MDCK cells were antigenically and structurally identical. In contrast, viruses from the same source, selected at limit dilution in eggs, could be divided into three distinct subpopulations based on the distinguishable antigenic and structural characteristics of their HA molecules. The three groups of egg-grown viruses could be distinguished from each other, and from MDCK cell-grown viruses, not only by a panel of anti-HA monoclonal antibodies, but also by immune ferret sera raised to H3N2 virus strains of recent years and sera raised to the different egg-grown clones themselves. Of these groups, group 1 and group 2 egg-grown viruses each represented a minor subpopulation of viruses which could be isolated in eggs, while viruses of the third antigenic phenotype were the most frequently isolated in eggs. Amino acid substitutions in the HA of egg-grown viruses occurred in antigenic and receptor-binding sites of the molecule. Group 1 viruses each possessed two amino acid substitutions in their HA molecules at residues 193 and 229 in HA1. Group 3 viruses, which displayed altered receptor specificities compared to MDCK cell-grown viruses and other egg-grown viruses, possessed a single amino acid substitution at residue 145 in HA1. The HA of the group 2 egg-grown viruses appeared structurally identical, yet displayed marked differences in antigenic and receptor-binding properties, compared to viruses isolated in MDCK cells. These results demonstrate that multiple, distinct subpopulations of virus can be isolated from a single patient during an infection with influenza and highlights the potential problems in selecting the most appropriate virus for epidemiological and vaccine purposes since selection could result in the use of viruses that are not representative of those which predominate in a human population.

Animals↗
PubMed1987

Characterization of subtype-specific and cross-reactive helper-T-cell clones recognizing influenza virus hemagglutinin.

The specificity and function of two T-cell clones derived from A/Memphis/1/71 (H3) influenza virus (Mem 71)-immune BALB/c spleen cells have been compared. One clone, X-31 clone 1, was subtype specific, proliferating in response to influenza strains of the H3 subtype only. The other, Jap clone 3, cross-reacted in proliferation assays with heterologous subtypes of influenza A, but not type B. Both clones recognized the HA1 chain of the hemagglutinin (HA) molecule and their proliferation in response to detergent-disrupted virus could be specifically inhibited by monoclonal antibodies to the HA. The T-cell clones were of the L3T4+ phenotype. Both recognized antigen in association with I-Ed, as indicated by studies with H-2 recombinant strains of mice and by blocking with monoclonal anti-I-E antibody. In vivo, both clones elicited a delayed-type hypersensitivity (DTH) reaction when inoculated into mouse footpads together with virus, X-31 clone 1 again displaying subtype specificity and Jap clone 3 being cross-reactive. The clones were also able to provide factor-mediated help in vitro to virus-primed B cells in an anti-HA antibody response. The cross-reactive T-cell clone provided help not only for B cells primed with influenza A subtype H3 and responding to H3 virus in culture, but also for H2 virus-primed B cells making anti-H2 antibody.

Animals↗
PubMed1987

Host cell-mediated variation in H3N2 influenza viruses.

The influence of the host cell on the selection of antigenic variants of influenza A H3N2 viruses and the relevance of host cell selection to the induction of immunity by these viruses have been investigated. Influenza viruses were isolated from human clinical samples during a single epidemic, were passaged in mammalian Madin-Darby Canine Kidney (MDCK) cells or in embryonated hens eggs, and were tested for antigenic variability in the hemagglutinin (HA) molecule with a panel of monoclonal antibodies. In many cases, the HA of virus cultivated in eggs was antigenically distinct from the HA of virus from the same individual grown in mammalian cells. Viruses recovered from different individuals were antigenically similar to each other when grown in mammalian cell lines yet were antigenically heterogeneous when cultivated in eggs. The HA genes of viruses isolated from different individuals during the epidemic were shown, by sequence analysis, to differ from each other by five or six amino acid residues. Sequence analyses of the HA genes of MDCK cell-grown and egg-grown virus obtained from the same individual demonstrated that the molecular changes between antigenically distinct HAs of MDCK cell- and egg-grown A/Mem/12/85 virus involved a single amino acid substitution at residue 156 in HA1, which lies at the tip of the HA molecule and immediately adjacent to the receptor-binding site. However, the amino acid sequences of HAs from MDCK-grown and egg-grown viruses (A/Mem/2/85) isolated from a second individual were identical although these viruses exhibited antigenic differences when examined with anti-HA monoclonal antibodies. Therefore, single amino acid changes in the HA molecule may not be the sole cause of antigenic changes in the HA observed between pairs of MDCK cell-grown and egg-grown viruses and genes other than that encoding the HA may contribute to the host cell-mediated antigenic variation of these viruses. Nevertheless, antigenic differences between viruses grown in eggs and MDCK cells did not influence their ability to protect, since ferrets infected with either live egg-grown or MDCK-grown virus were protected equally well from challenge with virus grown in either host cell type.

Amino Acid Sequence↗