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R Nisini

Publications and source records attributed to R Nisini.

At least 19 recordsLinked to original sources
PubMed2004

Antibody classes & subclasses induced by mucosal immunization of mice with Streptococcus pyogenes M6 protein & oligodeoxynucleotides containing CpG motifs.

BACKGROUND & OBJECTIVES: Type-specific antibodies against M protein are critical for human protection as they enhance phagocytosis and are protective. An ideal vaccine for the protection against Streptococcus pyogenes would warrant mucosal immunity, but mucosally administered M-protein has been shown to be poorly immunogenic in animals. We used a recombinant M type 6 protein to immunize mice in the presence of synthetic oligodeoxynucleotides containing CpG motifs (immunostimulatory sequences: ISS) or cholera toxin (CT) to explore its possible usage in a mucosal vaccine. METHODS: Mice were immunized by intranasal (in) or intradermal (id) administration with four doses at weekly intervals of M6-protein (10 microg/mouse) with or without adjuvant (ISS, 10 microg/mouse or CT, 0,5 microg/mouse). M6 specific antibodies were measured by enzyme linked immunosorbent assay using class and subclass specific monoclonal antibodies. RESULTS: The use of ISS induced an impressive anti M-protein serum IgG response but when id administered was not detectable in the absence of adjuvant. When used in, M-protein in the presence of both ISS and CT induced anti M-protein IgA in the bronchoalveolar lavage, as well as specific IgG in the serum. IgG were able to react with serotype M6 strains of S. pyogenes. The level of antibodies obtained by immunizing mice in with M-protein and CT was higher in comparison to M-protein and ISS. The analysis of anti-M protein specific IgG subclasses showed high levels of IgG1, IgG2a and IgG2b, and low levels of IgG3 when ISS were used as adjuvant. Thus, in the presence of ISS, the ratio IgG2a/IgG1 and (IgG2a+IgG3)/IgG1 >1 indicated a type 1-like response obtained both in mucosally or systemically vaccinated mice. INTERPRETATION & CONCLUSION: Our study offers a reproducible model of anti-M protein vaccination that could be applied to test new antigenic formulations to induce an anti-group A Streptococcus (GAS) vaccination suitable for protection against the different diseases caused by this bacterium.

Animals↗
PubMed2003

The interaction of human dendritic cells with yeast and germ-tube forms of Candida albicans leads to efficient fungal processing, dendritic cell maturation, and acquisition of a Th1 response-promoting function.

T helper cell type 1 (Th1) cell-mediated immunity plays a critical role in protection against the opportunistic pathogen Candida albicans. Virulence of the fungus is closely associated with its ability to form germ-tubes (GT), the early phase of the dimorphic transition from the commensal yeast (Y) to the more invasive hyphal (H) form. In this study, we examined the functional outcome of the interaction of Y or GT forms with human dendritic cells (DCs), professional antigen-presenting cells, which are pivotal for initiation and modulation of T cell responses. DCs phagocytosed and killed Y and GT cells with a comparable efficiency, becoming able to trigger strong proliferative responses by Candida-specific, autologous T cell clones. Both fungal forms induced DC maturation, as indicated by up-regulation of CD83, CD80, CD86, CD40, and major histocompatibility complex classes I and II surface antigens. Chemokine receptors were also modulated in Candida-DCs, which showed increased CCR7/CXCR4 and decreased CCR5 expression. Y- and GT-activated DCs differed in the pattern of cytokine expression. In particular, GT cells, in common with fully differentiated H cells, induced significantly more elevated levels of interleukin (IL)-10 than Y cells. Nevertheless, Y-, GT-, or H-pulsed DCs secreted comparable amounts of IL-12p70. In addition, irrespective of the fungal form triggering DC activation, Candida-DCs acquired the ability to prime naive T lymphocytes with a defined Th1 phenotype. Overall, our findings highlight the induction of substantially similar functional patterns in human DCs encountering the different forms of growth of C. albicans, both seemingly activating the Th1-type immunity which is characteristic of the healthy human subjects, naturally immunized and protected against the fungus.

Antigen-Presenting Cells↗
PubMed2001

The adjuvant effect of synthetic oligodeoxynucleotide containing CpG motif converts the anti-Haemophilus influenzae type b glycoconjugates into efficient anti-polysaccharide and anti-carrier polyvalent vaccines.

Synthetic oligodeoxynucleotides containing CpG immunostimulatory sequences (ISS) have been shown to act as potent adjuvants of type 1 immune responses when co-administered with protein or peptide vaccines. We have recently shown that ISS can increase the anti-polysaccharide (CHO) and anti-tetanus toxoid (TT) or anti-diphtheria (CRM) toxoid antibody levels if used as adjuvant of anti-Haemophilus influenzae type b (Hib) CHO vaccine conjugated with TT or CRM. The analysis of anti-TT and anti-CRM IgG subclasses showed a significant increase in IgG2a, IgG2b and/or IgG3 in the presence of ISS. Anti-TT and anti-CRM antibodies were shown to neutralize the activity of both the tetanus and diphtheria toxin in vivo or in vitro tests respectively. These data show that ISS have the potential to increase host antibody response against both the CHO and the protein component of a conjugated vaccine, and encourage the investigation to identify strategies of vaccination with schedules aimed at the valuation of protein carriers as protective immunogens.

Adjuvants, Immunologic↗
PubMed2001

Antigenic properties and processing requirements of 65-kilodalton mannoprotein, a major antigen target of anti-Candida human T-cell response, as disclosed by specific human T-cell clones.

T-cell-mediated immunity is known to play a central role in the host response to Candida albicans. T-cell clones are useful tools for the exact identification of fungal T-cell epitopes and the processing requirements of C. albicans antigens. We isolated human T-cell clones from an HLA-DRB1*1101 healthy donor by using an antigenic extract (MP-F2) of the fungus. Specific clones were T-cell receptor alpha/beta and CD4(+)/CD8(-) and showed a T-helper type 1 cytokine profile (production of gamma interferon and not interleukin-4). The large majority of these clones recognized both the natural (highly glycosylated) and the recombinant (nonglycosylated) 65-kDa mannoprotein (MP65), an MP-F2 minor constituent that was confirmed to be an immunodominant antigen of the human T-cell response. Surprisingly, most of the clones recognized two synthetic peptides of different MP65 regions. However, the peptides shared the amino acid motif IXSXIXXL, which may be envisaged as a motif sequence representing the minimal epitope recognized by these clones. Three clones recognized natural and pronase-treated MP65 but did not detect nonglycosylated, recombinant MP65 or the peptides, suggesting a possible role for polysaccharides in T-cell recognition of C. albicans. Finally, lymphoblastoid B-cell lines were efficient antigen-presenting cells (APC) for recombinant MP65 and peptides but failed to present natural, glycosylated antigens, suggesting that nonprofessional APC might be defective in processing highly glycosylated yeast proteins. In conclusion, this study provides the first characterization of C. albicans-specific human T-cell clones and provides new clues for the definition of the cellular immune response against C. albicans.

Amino Acid Sequence↗
PubMed2000

Synthetic oligodeoxynucleotide containing CpG motif induces an anti-polysaccharide type 1-like immune response after immunization of mice with Haemophilus influenzae type b conjugate vaccine.

Synthetic oligodeoxynucleotides containing CpG motifs [immunostimulatory sequences (ISS)] have been described as potent adjuvants of type 1 immune responses when co-administered with protein or peptide vaccines. To investigate their role in the immune response to polysaccharides (CHO), different preparations of anti-Haemophilus influenzae type b (Hib) conjugate vaccine were administered to mice. The unconjugated CHO did not induce the synthesis of specific antibodies even in the presence of ISS. On the other hand, anti-CHO-specific antibodies significantly increased in the presence of ISS, when tetanus (TT) or diphtheria [cross-reacting material (CRM)] toxoid-conjugated CHO were used to immunize mice. The adjuvant effect was also observed for the immune response against the carrier protein (TT and CRM). ISS insured an early and long-lasting specific IgG production. The effects of ISS on the anti-CHO immune response could be attributed to the amplification of the T help provided by the carrier. The analysis of anti-CHO IgG subclasses showed a significant increase of IgG2a and IgG3 in the presence of ISS. ISS caused a rapid release of IL-12 and IFN-gamma in sera from treated mice. This data provide a first evidence for the ability of ISS to induce an anti-CHO type 1-like immune response and demonstrate that ISS have the potential to increase host antibody response against both the CHO and the protein component of a conjugated vaccine.

Adjuvants, Immunologic↗
PubMed2000

Generation of a recombinant 65-kilodalton mannoprotein, a major antigen target of cell-mediated immune response to Candida albicans.

A 65-kDa mannoprotein (CaMp65) has long been studied as a major, immunodominant antigen of the human opportunistic pathogen Candida albicans. An expression library of C. albicans was screened with serum from mice immunized with ScMp65 (ScW10), a Saccharomyces cerevisiae recombinant protein of about 48 kDa. This serum recognized the CaMp65 from a cell wall extract of C. albicans. After cloning and sequencing of the relevant C. albicans cDNA, an open reading frame encoding a protein of 379 amino acids was identified. Its deduced amino acid sequence showed regions of identity with all previously characterized tryptic fragments of CaMp65, as well as with the corresponding regions of ScMp65. A prepeptide of 32 amino acids with signal peptidase and Kex2 cleavage sites as well as a high number of potential O-glycosylation sites but no N-glycosylation sites or GPI anchor were observed in sequence studies of CaMp65. A putative adhesin RGD sequence was also present in the C-terminal region of the molecule. This triplet was absent in the ScMp65. The relevant gene (designated CaMP65) was localized to chromosome R of C. albicans as determined by pulse-field gel electrophoresis. Northern blot analysis demonstrated that gene transcription was heat inducible and associated with germ-tube formation by the fungus. A recombinant, His(6)-tagged protein (rCaMp65) was expressed in Escherichia coli under an inducible promoter. After purification by nickel-chelate affinity chromatography, the recombinant product was detected as a 47-kDa protein band in immunoblots with the anti-ScMp65 serum, as well as with CaMp65-specific monoclonal antibodies. Both ScMp65 and CaMp65 were assayed for antigenic stimulation in cultures of peripheral blood mononuclear cells (PBMC) from 10 unselected human donors. While ScMp65 was substantially nonstimulatory, both rCaMp65 and the native CaMp65 were equally able to induce lymphoproliferation of the PBMC from all the donors. In addition, a number of CD4(+) T-cell clones were generated using a C. albicans mannoprotein fraction as an antigenic stimulant. Several of these clones specifically responded to both the native and the recombinant C. albicans Mp65 but not to ScMp65. Thus, the recombinant Mp65 of C. albicans retains antigenicity and, as such, could be a valid, standardized reagent for serodiagnostic and immunological studies.

Adult↗
PubMed1998

Generation of an MHC class II-restricted T cell epitope by extracellular processing of hepatitis delta antigen.

Hepatitis delta virus is a human pathogen that is responsible for a severe form of hepatitis affecting hepatitis B envelope Ag carriers. We have previously identified a series of hepatitis delta Ag (HDAg) epitopes that are recognized by CD4+ T cell clones isolated from infected subjects. Herein, we show that the presentation of soluble HDAg to CD4+ T cell clones that are specific for the HDAg(106-121) epitope was exceptionally unaffected by the inhibition of the APC-processing machinery when APCs were fixed with glutaraldehyde before Ag pulsing or treated with chloroquine or brefeldin A. Interestingly, 5 h of pulsing was strictly required for the efficient presentation of the HDAg(106-21) epitope by fixed APCs, suggesting that some form of extracellular processing had occurred. Indeed, fixed APCs were able to present HDAg after only 1 h of pulsing when HDAg was preincubated with serum for 5 h. More important, presentation was completely abrogated when Ag was previously incubated in medium containing serum in the presence of a potent inhibitor of trypsin activity such as the secretory leukoprotease inhibitor. These results show that HDAg may undergo extracellular processing and suggest that the generation of immunogenic epitopes directly by serum proteases could play a role in the immune response against hepatitis delta virus during infection.

Amino Acid Sequence↗
PubMed1998

Isoelectricfocusing and reverse blotting as a diagnostic tool in pediatric HIV infection.

BACKGROUND: Early diagnosis of perinatally acquired HIV-infection is based on either direct HIV detection--by means of viral culture and/or PCR--or anti-HIV antibody detection. However, due to the passive, transplacental passage of maternal immunoglobulin G, antibody detection is nor reliable until 15-18 months of age. In this regard, clonotypic analysis of specific antibodies performed by isoelectricfocusing and reverse blotting (IEF-RB) can be very helpful, as it recognizes possibly different patterns between mother and infant. OBJECTIVES: We used IEF-RB in order to analyze the kinetics of development of anti-HIV antibodies in infants born to seropositive mothers. STUDY DESIGN: Sera from ten mother/infant pairs (all mothers were HIV-infected) were retrospectively analyzed in order to detect different patterns, between mother and infant, in anti-gp120 V3-loop clonotype. RESULTS: We diagnosed the real HIV status of the examined infants no later than month 6 and in one case as early as month 2. CONCLUSIONS: Considering the small size of sample number, these data are preliminary and should be confirmed by larger scale studies. However, they show IEF-RB, when applied to infants born to seropositive mothers, may be useful in evaluating the infants' dynamics of anti-HIV humoral immune response.

Antigens, Viral↗
PubMed1998

Autoimmune T-cell response to the CD4 molecule in HIV-infected patients.

In a previous study, we demonstrated that by downregulating plasma membrane CD4 and increasing its processing, human immunodeficiency (HIV)-1-gp120 unveils hidden CD4 epitopes, inducing an in vitro anti-CD4-specific T-cell response. We report herein that this mechanism may potentially have important implications in HIV immunopathogenesis, because it could take part in the severe depletion of CD4+ cells that characterizes acquired immune deficiency syndrome (AIDS) and be related to disease progression. Freshly isolated peripheral blood lymphocytes (PBMC) from about 1/4 of a conspicuous cohort of HIV-infected patients responded to CD4 and this response was correlated with beta2-microglobulin levels, widely recognized as marker for progression of HIV infection. Moreover, we provide evidence that a CD4-specific T cell priming can occur in vivo, following a gp120 or anti-CD4 monoclonal antibody (mAb)-mediated CD4 molecule downregulation on antigen-presenting cells (APC). To our knowledge, this is the first study indicating that an autoimmune T-cell response is linked to HIV infection and that it could have an important impact on the immunopathogenesis of this disease.

Adult↗
PubMed1997

Cross sectional retrospective study of prevalence of atopy among Italian military students with antibodies against hepatitis A virus.

OBJECTIVE: To investigate the working hypothesis that common infections occurring early in life prevent atopy. DESIGN: Cross sectional, retrospective study of young Italian men with results for hepatitis A serology and atopy. SETTING: Air force school of military students in Caserta, Italy. SUBJECTS: 1659 male students aged 17-24, most of whom (90%) were from central and southern Italy. MAIN OUTCOME MEASURES: Skin sensitisation and specific IgE antibodies to locally relevant airborne allergens; diagnosis of respiratory allergy (asthma or rhinitis, or both); hepatitis A seropositivity. RESULTS: 443 of the 1659 subjects (26.7%) were positive for hepatitis A virus antibody. Atopy was less common among seropositive than seronegative subjects according to skin sensitization (weal reaction > or = 3 mm) to one or more allergens (21.9% (97/443) v 30.2% (367/1216), P < 0.001); polysensitisation (sensitive to three or more allergens) (2.7% (12/443) v 6.4% (78/1216), P < 0.01); high specific IgF concentration (9.7% (43/443) v 18.4% (224/1216), P < 0.00005); and lifetime prevalence of allergic rhinitis or asthma, or both (8.4% (37/443) v 16.7% (203/1216), P < 0.001). Hepatitis A seropositivity remained inversely associated with atopy after adjusting for father's education, the number of older siblings, and the area of residence (based on the number of inhabitants). The prevalence of atopy was constantly low among seropositive subjects, whatever the number of older siblings; by contrast, it increased with a decreasing number of older siblings among seronegative subjects. CONCLUSION: Indirect but important evidence is added to the working hypothesis as common infections acquired early in life because of the presence of many older siblings (among seronegative subjects) or because of unhygienic living conditions (among seropositive subjects) may have reduced the risk of developing atopy.

Adolescent↗
PubMed1997

Fas/Apo1 mutations and autoimmune lymphoproliferative syndrome in a patient with type 2 autoimmune hepatitis.

Inherited mutations of the Fas/Apo1/CD95 gene, a cell-surface receptor involved in cell death signaling and in the control of self-reactivity, characterize the recently identified autoimmune lymphoproliferative syndromes. A patient with type 2 autoimmune hepatitis with the immunologic and genetic features of autoimmune lymphoproliferative syndrome is described. The clinical picture was dominated by liver disease with hepatosplenomegaly and positivity for anti-liver-kidney microsome 1 and anti-liver-cytosol 1 antibodies. A marked increase in CD3+CD4-CD8-T lymphocytes and inherited mutations in Fas alleles that led to the expression of a soluble form of the protein were also found. Fas-mediated apoptosis was deficient in the patient as it was in her mother and her sister, who carried the same allele 2 mutation. This observation links type 2 autoimmune hepatitis, an organ-specific disease, with a genetically determined defect in peripheral tolerance control.

Alleles↗
PubMed1997

Human CD4+ T-cell response to hepatitis delta virus: identification of multiple epitopes and characterization of T-helper cytokine profiles.

The T-cell-mediated immune response plays a crucial role in defense against hepatotropic viruses as well as in the pathogenesis of viral chronic hepatitides. However, very little is known about the role of specific T cells during hepatitis delta virus (HDV) infection in humans. In this study, the T-cell response to HDV in chronic hepatitis B virus (HBV) carriers with HDV superinfection was investigated at different levels. Analysis of peripheral blood mononuclear cell (PBMC) proliferation in response to a recombinant form of large hepatitis delta antigen (HDAg) revealed that 8 of 30 patients studied (27%) specifically responded to HDAg. By employing synthetic peptides spanning the entire HDAg sequence, we found that T-cell recognition was directed against different antigenic determinants, with patient-to-patient variation in the pattern of response to peptides. Interestingly, all responders had signs of inactive HDV-induced disease, while none of the patients with active disease and none of the control subjects showed any significant proliferation. More accurate information about the specific T-cell response was obtained at the clonal level. A panel of HDAg-specific CD4+ T-cell clones from three HDV-infected individuals and fine-specificity analysis revealed that the clones tested individually recognized four epitopes corresponding to amino acids (aa) 26 to 41, 50 to 65, 66 to 81, or 106 to 121 of HDAg sequence. The study of human leukocyte antigen (HLA) restriction revealed that peptides 50 to 65 and 106 to 121 were presented to specific T cells in association with multiple class II molecules. In addition, peptide 26 to 41 was efficiently generated after processing of HDAg through the endogenous processing pathway. Cytokine secretion analysis showed that all the CD4+ T-cell clones assayed were able to produce high levels of gamma interferon (IFN-gamma), belonging either to T helper-1 (Th1) or Th0 subsets and that some of them were cytotoxic in a specific assay. This study provides the first evidence that detection of a specific T-cell response to HDAg in the peripheral blood of individuals with hepatitis delta is related to the decrease of HDV-induced disease activity. The HDAg epitopes identified here and particularly those recognized by CD4+ T cells in association with multiple major histocompatibility complex class II molecules may be potentially exploited for the preparation of a vaccine for prophylaxis and therapy of HDV infection.

CD4-Positive T-Lymphocytes↗
PubMed1996

One cause for the apparent inability of human T cell clones to function as professional superantigen-presenting cells is autoactivation.

Human T cell clones (TCC) are antigen-presenting cells (APC) able to present peptides and superantigens (SAg) and to process and present intact proteins. TCC express major histocompatibility complex (MHC) class II antigens and molecules involved in the accessory signal delivery, such as B7.1 and B7.2/B70. Notwithstanding these observations, the role of professional APC has been often denied to T cells because anergy of responder T cells rather than proliferation has been observed following the TCC presentation in the absence of added professional APC. Here, we show that upon stimulation with free SAg, TCC undergo proliferative responses followed, after a 1-week culture, by an SAg-dependent unresponsiveness to T cell receptor (TCR)-mediated stimuli, but not to interleukin-2. The anergy induced by the SAg can not be prevented by the addition of autologous Epstein-Barr virus (EBV)-transformed B cells, indicating that the induction of anergy occurs also in the presence of conventional APC. Conversely, if the TCC are stimulated by SAg-prepulsed irradiated APC, either EBV and TCC, the induction of anergy is not observed. After a 1-week culture, in fact, TCC stimulated with APC-bound SAg responded to TCR-mediated stimuli, irrespective of the APC (EBV or TCC) used for the SAg presentation. Stimulation of TCC with free SAg in a semisolid medium that prevents T-T cell contacts resulted in an activation followed by a state of anergy, suggesting that anergy is the consequence of SAg recognition at the single T cell level. These data indicate that the anergy observed in TCC upon a 1-week culture in the presence of soluble SAg is not the result of an inherent inability of TCC to act as professional APC. Rather the phenomenon depends on the presence of soluble SAg, leading to T cell autostimulation.

Agar↗
PubMed1996

Two brc-abl junction peptides bind HLA-A3 molecules and allow specific induction of human cytotoxic T lymphocytes.

Intracellular processing of the products of the bcr-abl junction region in CML Philadelphia chromosomes would generate novel peptides which, if they are capable of binding to HLA-class I molecules, would be potential targets of a cytotoxic T cell response. The 18 nonamers corresponding to the b2-a2 and b3-a2 fusions and differing from the parental bcr and abl sequences for at least one amino acid have been synthesized and tested for binding with HLA class I alpha chain preparations from HLA-homozygous B lymphoblastoid cell lines. Two peptides derived from the b3-a2 junction bound to HLA-A3 and elicited detectable specific CTL responses in vitro. The binding affinity of one of the two peptides could be increased by appropriate substitutions of the anchor residues with those of the known HLA-A3 anchor motifs. More important, the modified peptide had increased capacity to prime a specific CTL response in vitro. The interaction with HLA-A3 of these two peptides and their substitution derivatives seems to be promising for target trials aimed at eliciting a specific CD8 T cell response against CML.

Amino Acid Sequence↗
PubMed1995

Rhodamine 123: a useful probe for monitoring T cell activation.

The T cell activation pathway involves an increase in mitochondrial activity. This can be evaluated in individual cells using the fluorescent probe rhodamine 123 (Rh123) and flow cytometry. Peripheral blood mononuclear cells (PBMC) were stimulated with optimal concentrations of phytohaemagglutinin (PHA), superantigens (Sag) SEA and SEC2, and allogeneic cells. Activation kinetics were followed at days 1, 2, 4 and 7. In all activation conditions, Rh123 uptake was augmented with the CD25 expression, cell size, and DNA synthesis. Rh123 uptake reflected an increase in mitochondrial activity and mass, as assessed by experiments in which Rh123 was substituted for by the 10-nonyl acridine orange, which stains mitochondria in an energy-independent manner. The spectral characteristics of Rh123 allowed us to double stain cells with Rh123 and phycoerythrin-conjugated monoclonal antibodies. In PHA-activated cultures, CD4+ and CD8+ cells incorporated essentially the same amount of Rh123 at all time points, suggesting that the two subsets did not differ in their activation kinetics. Accordingly, after 1 week of culture, no significant modification in the CD4/CD8 ratio was observed. Sag-activated CD4+ cells incorporated a higher amount of Rh123 than did CD8+ cells and preferentially expanded after 1 week of culture as indicated by the increase in the CD4/CD8 ratio. The different behavior of the CD4 and CD8 subsets observed by dual color flow cytometry in the PHA and Sag models was confirmed using purified CD4+ and CD8+ cell preparations obtained by immunomagnetic sorting. CD4+ cells were also the preferential target in the allogeneic model, although the magnitude of the phenomenon was lower than in the Sag model. Present data indicate that Rh123 is a reliable marker for monitoring the mitochondrial compartment during T cell activation. The possibility of phenotyping Rh123-stained cells adds to the applicability of the probe.

CD4-Positive T-Lymphocytes↗
PubMed1995

Infection of circulating and liver infiltrating T cells by hepatitis C virus of different subtypes.

Hepatitis C virus (HCV) infection display a very high rate of progression to chronicity and, like many other viruses causing persistent infections, it displays a tropism for the cells of the immune system. Peripheral blood mononuclear cells (PBMCs) from 21 HCV chronic carriers and long-term T cell clones derived from circulating or liver infiltrating T lymphocytes were tested by cDNA "nested" PCR for positive and negative strand HCV-RNA. The presence of HCV genomes in PBMCs is a frequent, although not constant, finding and can be accompanied by active viral replication, as suggested by the coexistence of negative strand HCV-RNA. Infected T cells are more represented in livers than in periphery, as indicated by comparing HCV-RNA detection in T cell clones isolated from both the compartments. Sequencing of viral genomes present in PBMCs and liver infiltrating lymphocytes showed that all the three major HCV genotypes present in our population of chronic carriers can infect lymphoid cells. Although each clonal population of T cells is infected by a single strain of HCV, in the same patient lymphoid cells can harbor different viral populations, different from those circulating at that moment in the serum.

Adult↗
PubMed1995

Spectrotypic analysis of antibodies to Helicobacter pylori in patients with antral gastritis and duodenal ulcer.

AIMS: To investigate the anti Helicobacter pylori (H pylori) spectrotype associated with (a) antral gastritis and duodenal ulcer; (b) the H pylori eradicating treatment. METHODS: Spectrotypic analysis was performed by isoelectric focusing and reverse blotting (IEFRB) in a cross sectional study on sera from 70 patients with antral gastritis and duodenal ulcer. In addition, a longitudinal study was performed on 40 of these patients (20 with antral gastritis and 20 with duodenal ulcer) who underwent eradicating treatment. RESULTS: The cross sectional study showed that the oligoclonal spectrotype was present in 74% of antral gastritis patients and in 85% of duodenal ulcer patients. In only a minority of subjects (23% with antral gastritis and 3% with duodenal ulcer) was a polyclonal spectrotype observed. The longitudinal study showed a reduction in the intensity of the spectrotypic bands in 5/10 antral gastritis patients with eradicated H pylori as opposed to only 2/10 patients without eradication. A reduction was also observed in 6/11 eradicated v 0/9 non-eradicated patients with duodenal ulcer. Collectively, a reduction in the spectrotype was observed in 11/21 patients (52%) who--independently of the disease--underwent H pylori eradication, as opposed to 2/19 of the non-responder patients (10.5%). The polyclonal spectrotype was found exclusively in four patients with antral gastritis, all belonging to the group without eradication of H pylori after eradicating treatment. CONCLUSIONS: The anti H pylori oligoclonal spectrotype is the most common pattern observed in patients with antral gastritis and duodenal ulcer. After H pylori eradicating treatment the spectrotype does not change qualitatively, but the polyclonal pattern seems to be predictive of a poor response to eradication.

Adolescent↗