[New pertussis vaccines are tested].
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Biomedical subjects
Publications and source records attributed to H Wigzell.
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Three monoclonal antibodies (mAb) 2D1, 3B9, and 3B12 were produced by immunizing BALB/c mice with JURKAT cells. These mAb induce comodulation of the TCR/CD3 complex expressed on JURKAT cells, but do not react with the CD3- JURKAT variant, J.RT3.T3.1. Immunoprecipitation studies with detergent-solubilized JURKAT cell lystes indicate that these mAb react with proteins having characteristics of the TCR molecules. Their low reactivity with peripheral blood mononuclear cells (PBMC) and lack of reactivity with other CD3+ T cell lines suggest that they may be anti-idiotypic mAb. Results from binding inhibition assays, reactivity with PBMC, and generation of transmembrane signals suggest that these three anti-TCR mAb recognized different epitopes on the TCR beta chain of JURKAT cells. Although the three mAb are capable of inducing the production of inositol phosphates and cytosolic free Ca2+ increase in JURKAT cells, their stimulatory capacities vary and are lower than that observed by anti-CD3 antibody (OKT3) stimulation. However, crosslinking these mAb with rabbit antimouse immunoglobulins potentiates the stimulatory response to comparable levels induced by OKT3. These mAb could be useful as tools to study V beta 8+ T cells in relation to antigen-specific activation.
The alpha/beta T cell receptor (TcR) V gene usage of bronchoalveolar lavage (BAL) lymphocytes and peripheral blood lymphocytes (PBL) from 11 sarcoidosis patients and 4 healthy controls was investigated, using eight alpha/beta TcR V gene product-specific monoclonal antibodies (mAb). Twenty-seven percent (3/11) of the sarcoidosis patients had a highly significant increase in V alpha 2.3+CD4+ T lymphocytes in the bronchoalveolar space, while displaying normal frequencies of these T cells in peripheral blood. The reactivities with the remaining seven TcR mAb were normal. In the control group, no compartmentalization of any T cells was seen. Four of the patients expressed the HLA-DR3 (w17), DQw2 haplotype. Interestingly, the three patients with distinct signs of compartmentalized V alpha 2.3+CD4+ T cells all expressed this HLA haplotype. Additionally, a fourth patient with pronounced, although less significant, accumulation of V alpha 2.3+CD4+ T cells in the lung, was also HLA-DR3(w17), DQw2+. Expression of V alpha 2.3+CD4+ T cells in BAL of these patients correlated with clinical disease, as revealed on re-analyzing the four patients after 6 months or longer. Predominant TcR V alpha 2.3 gene usage in compartmentalized CD4+ BAL T lymphocytes, linked to HLA-DR3(w17), DQw2 haplotype, may thus indicate presence of a specific antigen localized to the lungs of sarcoidosis patients.
A simple, rapid, reproducible and sensitive peptide-Time-Resolved-Fluoroimmunoassay (TR-FIA) method is described which allows the detection of antibodies to the Human Immunodeficiency Virus type 1 (HIV-1). By using a panel of synthetic peptide antigens that covered env, gag and pol amino acid sequences, a 20 amino acid peptide (GIWGCSGKLICTTAVPWNAS) describing an immunodominant and conserved domain on the gp41 region of the BH10 clone was found to be the most reactive in this study. Optimal conditions for antigen concentration, serum dilution and incubation time were established. The peptide-TR-FIA is specific, as assessed by testing HIV-1 positive sera which included samples from AIDS, ARC patients and HIV-positive drug users. The test was used to detect HIV antibodies in 250 well characterized HIV-1 positive sera and 50 normal sera. Peptide-TR-FIA results indicate that the env peptide was highly reactive with HIV-positive sera showing a sensitivity of 100%. None of the 50 control sera showed positive reactivity against the synthetic peptide. Furthermore the peptide-TR-FIA allowed a fine titration of antibodies to defined epitopes of immunodominant HIV structural proteins that usually cannot be achieved by peptide-ELISA assays.
To analyze which gene of HIV-1 was responsible for the high accumulation of "heterodisperse RNAs" in virally infected T-cells, Northern blot analysis was performed. Total RNA from inducible cell lines expressing the envelope protein of HIV-1, or the regulatory gene rev, were blotted and hybridized with an Alu probe that detects heterodisperse RNAs. Results show that the rev gene is responsible for the accumulation of cellular heterodisperse RNAs seen earlier in HIV-1-infected T-cells.
During the last decade there has been a rapid progress in the development of new, much improved vaccines against cholera. These vaccines, which are given orally to stimulate the gut mucosal immune system, are based on either a combination of purified cholera toxin B (binding) subunit and killed cholera vibrios of Inaba and Ogawa serotypes and El Tor and classical biotypes (B subunit-whole cell vaccine, B-WC) or on a live attenuated mutant strain of Vibrio cholerae producing the B subunit (CVD 103-HgR). The safety of the oral B-WC cholera vaccine and the immunogenicity and protective efficacy of this vaccine against both cholera and diarrhoea caused by enterotoxigenic Escherichia coli have been extensively documented, e.g. in a large randomized, placebo-controlled field trial in 90,000 persons living in a cholera endemic area. The potential for inexpensive large-scale manufacturing of the B-WC vaccine has recently been much facilitated by the introduction of recombinant DNA technology for production of the B subunit component. This now gives promise that this vaccine could become a useful, cost-effective tool in future strategies to control cholera both in endemic situations and in relation to acute epidemic outbreaks.
We have investigated the effect of soluble recombinant CD4 (sCD4) on the antigen specific (BCG, peptides of mycobacterial 65 kDa hsp) responses of T cell lines of T cell clones. The majority of the antigen specific clones could be suppressed in their antigen driven response by the addition of sCD4, while others, including the parental polyclonal T cell line, were not. The suppression of the specific T cell response was reversed by the addition of anti-CD3, did not affect the proliferative response to IL-2, and was independent of the amount of antigen. A decreased capacity to produce IFN-gamma in response to the antigen by the addition of sCD4 was seen only with those clones that were also inhibited in their specific proliferative response. This model may be used to delineate further the interaction between T cells and the antigen presenting cell, and the finding may limit the possible in vivo use of sCD4 in the therapy of human immunodeficiency virus (HIV) infections.
Certain T cell antigen receptor V gene products in man have been shown by us and others to display a reproducible bias for preferential expression in CD4+ or CD8+ T cell subsets. In order to investigate whether such a skewed representation of V gene segments is also present at the J gene segment level, we tested the relative J beta gene usage by V beta 5.1 + T cells, as this V beta gene is biased towards CD4+ T cell expression in virtually all individuals. To analyze the usage of the 13 J beta gene segments, we developed a new approach using V beta 5.1 and C beta specific oligonucleotides as 5' and 3' primers respectively for polymerase chain reaction (PCR) amplification of cDNA derived from CD4+ or CD8+ peripheral blood lymphocyte (PBL) T cells. The PCR products were visualized for reactivity with individual J beta 1.1-1.6 and J beta 2.1-2.7 32P-labelled oligonucleotide probes using autoradiography and quantitative gel-scanning. Eleven normal blood donors provided the PBL T cells. The results showed that in every individual's V beta 5.1+ T cell populations (CD4 and CD8), all V beta/J beta combinations were used although at varying but reproducible levels for each J beta gene. Thus, no discernible disallowance of combinations existed. Moreover, we could show that six of 13 J beta genes were unequally expressed when compared in pairs with regard to expression in CD4+ and CD8+ T cell subsets.(ABSTRACT TRUNCATED AT 250 WORDS)
OBJECTIVE: To analyse the pattern of immunoglobulin (Ig) G subclasses specific for HIV-1 envelope peptides in sera from HIV-1-infected mothers and their newborns. We sought to determine whether there was a selective transfer of antibodies from mother to child, and to establish diagnostic or prognostic properties by analysing HIV-1 peptide-specific IgG isotypes. DESIGN AND METHODS: Parallel sera from 12 HIV-1-infected mothers and their newborn children were analysed for IgG subclass responses to six HIV-1 envelope peptides by enzyme-linked immunosorbent assay. Levels of IgG were compared with levels of IgG1 and IgG3 to an immunodominant gp41 peptide in children's sera obtained during the first months of life. In a longitudinal study of 16 children born to HIV-1-seropositive mothers, of whom 11 were infected, the IgG1 and IgG3 responses to peptides representing an immunodominant epitope of gp41 and the principal neutralizing determinant of the gp120 V3 region were analysed. RESULTS: IgG1 and IgG3 were found to constitute the predominant peptide-specific antibody responses. A parallel distribution of IgG subclass reactivity was seen in maternal and paediatric sera. There was no evidence of selective antibody transfer. Comparable levels of IgG and IgG1 to the immunodominant peptide were seen in infected and uninfected children, while the IgG3 had disappeared in the majority of uninfected children. A decrease in peptide-specific IgG1 and IgG3 levels was observed in sequential sera from uninfected children, although the kinetic profile varied. Sera from infected children showed de novo synthesis of IgG1 and/or IgG3 binding to the selected HIV-1 peptides. Most children with rapid disease progression failed to produce IgG1 and/or IgG3 to the V3 peptide. CONCLUSION: Analysis of IgG subclass kinetics to selected HIV-1 peptides might be a useful additional diagnostic and prognostic tool in evaluating HIV-1 infection in children born to seropositive mothers.
A dramatic and persistent T cell expansion in a healthy adult male was initially identified, using anti-T cell receptor for antigen (TCR)-specific MoAbs. The expanded T cells were found to be expressing TCR containing V alpha 12.1 and V beta 5.2, and they composed approximately one third of all the CD8+ T cells. The cells were shown to be not only non-activated (HLA-DR-, IL-2R-) but also of 'virgin' cell type (CD45RA+/CD45RO-) and they persisted over the observation period of more than one and a half years. Various T and B cell markers, and all other laboratory and physical parameters analysed, were normal. The expanded CD8+ T cells were further characterized by polymerase chain reaction (PCR) amplification, using V beta- and C beta-specific primers, followed by hybridization with J beta-specific probes. Close to 90% of the V alpha 12.1+ V beta 5.2+ T cells were found to utilize the J beta 2.5 gene segment, thus strongly suggesting the expanded T cells to be monoclonal. The condition may constitute a T cell counterpart to 'monoclonal gammopathy of undetermined significance' (MGUS), and by analogy we suggest it should be designated 'monoclonal T cell expansion of undetermined significance' (MTUS).
We have previously analysed the T-cell receptor (TCR) V-gene usage in peripheral blood T lymphocytes from a group of healthy Scandinavians, and described a biased representation (i.e. a statistically significant higher median representation) for some of the TCR V genes towards the CD4+ subpopulation. In a subsequent study the usage of the same V genes was analysed in single positive (CD4+ CD8- and CD4- CD8+) human thymocytes, and a similar type of skewness was noted. These observations might be explained by an influence of the specificity of the TCR of thymocytes on the maturation into the CD4+ or the CD8+ lineage. Such a model would assume an interaction between a common determinant on the major histocompatibility complex (MHC) class I or class II molecules, or with a peptide that is preferentially presented by either of the two molecules, and the TCR on the maturing thymocyte. To investigate the possible influence of a different genetic background and environment on skewed TCR V-gene representation, we have in this study analysed the TCR V-gene usage in peripheral blood and umbilical cord blood lymphocytes obtained from Asians, with a different ethnic and environmental background from our previous Scandinavian subjects. In the umbilical cord blood lymphocytes the TCR V-gene usage was close to identical between the two different ethnic groups in both CD4+ and CD8+ subpopulations. Analysing the peripheral blood lymphocyte (PBL) TCR V-gene usage, we found that three of the four monoclonal antibodies (MoAb) with a biased reactivity towards the CD4+ subpopulation in the Scandinavian group also showed a similar skewed reactivity in this study. Thus, the majority of the TCR V genes were used in a similar way. Some minor but definite discrepancies could be detected when comparing TCR V-gene usage in adult individuals from these two different ethnic groups. These differences could be inferred to be due to selective peripheral expansion through environmental pressure of T cells utilizing a specific V beta gene segment. We conclude that a striking preservation of biased TCR V-gene usage does exist in humans of distinctly different ethnic origin.
The kinetic profile of cytokine gene expression in normal human peripheral mononuclear cells (MNC) activated by an anti-CD3 monoclonal antibody was studied. The presence or absence of 10 different cytokine mRNA were measured in a polymerase chain reaction (PCR) assisted mRNA amplification assay. After 2 h of stimulation the mRNA for interleukin-1 alpha (IL-1 alpha), interleukin-2 (IL-2), interleukin-3 (IL-3), tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) were detectable and remained present during the whole time period studied (22 h). Interleukin-6 (IL-6) and granulocyte macrophage colony stimulating factor (GM-CSF) were detected after 4 h, while interleukin-10 (IL-10) mRNA did not appear until after 7 h; they all remained expressed at 22 h. A transient expression of interleukin-4 (IL-4) mRNA was observed between 4 and 7 h of stimulation. No gene expression of granulocyte colony stimulating factor (G-CSF) was detected at any time. These results show that anti-CD3 stimulation of MNC leads to a rapid sequential induction of different cytokine mRNA, some with a very transient expression.
Evidence is presented for the existence of a serum factor(s) (SF), which inhibits the growth of both the interleukin-2 (IL-2)-dependent cell line CTLL and the 2-day generation of CTL cells. This activity is found in the serum of both nude and euthymic mice and its suppressive effect can be detected about 18 hours after addition to CTLL cultures. The inhibitory activity elutes from a Sepharose 6B gel after the gamma globulin fraction (100-150 kD), and is precipitated by ammonium sulfate at 60 w/v% saturation. IL-3-mediated bone marrow colony formation is not inhibited by SF. It also does not suppress the growth of a panel of different tumor cell lines. The spleen cell responsiveness to both Con A and LPS activation is greatly reduced in the presence of SF. However, binding of radiolabelled IL-2 to CTLL cells was not blocked by SF, although the activity was greatly reduced by absorption to these cells. Our data support the existence of factor(s) in sera that may have a regulatory role on IL-2-mediated functions.
An experimental system has been established to understand the poor interleukin-2 (Il-2) production by activated thymocytes. This model system is further characterized here and studies were done on the possible mechanism(s) involved. Thymocytes activated by Concanavalin-A (Con-A), or through the CD3 complex of the T-cell receptor (TCR), inhibit 95-99% of the Il-2 production by spleen cells, while thymocytes stimulated by rIl-2 or lipopolysaccharides (LPS) do not. The mechanism of inhibition is not due to production of soluble factors, consumption of available interleukin-1 (Il-1) or Il-2, but is dependent on cell-to-cell contact. Although cellular contact is needed, cytotoxicity is not involved. Prostaglandin production is not required for the generation or exertion of the inhibitory activity. Protein and DNA synthesis are necessary for exertion of the suppressive effect. We also demonstrate a genetic difference between different mouse strains in the ability to generate the inhibitory thymocytes. Activated Balb/c thymocytes inhibit spleen cells' Il-2 production in a non-MHC-restricted manner. Our studies demonstrate a regulatory capacity of activated thymocytes in vitro. This ability of the postnatal cells could be of relevance for understanding the latter events in T-cell education in the thymus and the role of Il-2 during this process.
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Over the past twenty-five years, many authors have reported evidence of the immunoprotective capacity of ribosomes isolated from bacteria, fungi and parasites. Since 1971 we have explored the protective capacity of ribosomes isolated from a large variety of micro-organisms responsible for human and animal diseases. Accurate biochemical characterization of ribosomes always reveals trace amounts of non-ribosomal components such as short polysaccharides strongly linked to ribosomal RNA after phenol extraction even under denaturing conditions. rRNA-antigen complexes have been purified from Klebsiella pneumoniae ribosomes inducing high level of protection against homologous experimental infection in mice. Monoclonal antibodies raised against ribosomes and then selected for their ability to confer passive immunity to mice have been used to study the mechanism of the protection induced by ribosomes and to characterize their "immunogenic principle". These investigations have clearly shown the presence on ribosomes of epitopes corresponding to antigens normally exposed on the membrane of the bacteria. In the original concept of "ribosomal immunotherapy" that we have developed, ribosomes can be considered as natural carriers for cell surface epitopes, presenting them to the immune system in a highly immunogenic configuration.
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An earlier study showed that approximately 5% of HIV-seropositive human sera contain gp120 antibodies that mimic CD4, seen as anti-idiotypic to the CD4 monoclonal T4.2. The present study shows the existence of a second type of CD4-mimicking gp120 antibody, which specifically binds to the CD4 monoclonal, OKT4A. This anti-idiotypic antibody to OKT4A is less frequent than the antibody reacting with T4.2. In two patients studied, this OKT4A binding antibody seems to appear as early during infection as the anti-idiotypic antibody to T4.2; however, the concentration varies more with time. In order to evaluate the possible clinical relevance of these CD4-mimicking antibodies, sera from 208 HIV-seropositive and 204 healthy seronegative individuals were screened. There was a significantly higher frequency of anti-idiotypic antibodies to T4.2 among HIV-positive individuals compared to healthy controls (p = 0.05). However, no correlation was found between the presence of CD4-mimicking antibodies and clinical classification of HIV-infected individuals.