Plasmacytoid dendritic cells proliferation associated with acute myeloid leukemia: phenotype profile and mutation landscape

Neoplasms involving plasmacytoid Dendritic Cells (pDCs) include Blastic pDC Neoplasms (BPDCN) and other pDC proliferations, where pDCs are associated with myeloid malignancies: most frequently Chronic MyeloMonocytic Leukemia (CMML) but also Acute Myeloid Leukemia (AML), hereafter named pDC-AML. We aimed to determine the reactive or neoplastic origin of pDCs in pDC-AML, and their link with the CD34+ blasts, monocytes or conventional DCs (cDCs) associated in the same sample, by phenotypic and molecular analyses (targeted NGS, 70 genes). We compared 15 pDC-AML at diagnosis with 21 BPDCN and 11 normal pDCs from healthy donors. CD45low CD34+ blasts were found in all cases (10-80% of medullar cells), associated with pDCs (4-36%), monocytes in 14 cases (1-10%) and cDCs (2 cases, 4.8-19%). pDCs in pDC-AML harbor a clearly different phenotype from BPDCN: CD4+ CD56- in 100% of cases, most frequently CD303+, CD304+ and CD34+; lower expression of cTCL1 and CD123 with isolated lymphoid markers (CD22/CD7/CD5) in some cases, suggesting a pre-pDC stage. In all cases, pDCs, monocytes and cDC are neoplastic since they harbor the same mutations as CD34+ blasts. RUNX1 is the most commonly mutated gene: detected in all AML with minimal differentiation (M0-AML) but not in the other cases. Despite low number of cases, the systematic association between M0-AML, RUNX1 mutations and an excess of pDC is puzzling. Further evaluation in a larger cohort is required to confirm RUNX1 mutations in pDC-AML with minimal differentiation and to investigate whether it represents a proliferation of blasts with macrophage and DC progenitor potential.

Altered thymic CD4+ T-cell recovery after allogeneic hematopoietic stem cell transplantation is critical for nocardiosis

PURPOSE OF THE STUDY

Nocardia affects immunocompromised human host exhibiting an altered cell-mediated immunity. Infectious risk after allogeneic hematopoietic cell transplantation (AHCT) is significantly correlated to the recovery status of donor-derived immune system, especially CD4⁺ T-cells reconstitution and thymopoiesis. The purpose of this paper is to highlight a lack of cell-mediated immunity recovery for patients presenting a nocardiosis compared to a control cohort.

PATIENTS AND METHODS

This is a case control retrospective monocentric study. We retrospectively analyzed a monocentric cohort of 15 cases of nocardiosis after AHCT and we explored the degree of patients' immunosuppression by phenotyping circulating lymphoid subpopulations, including NK cells, CD8⁺ T-cells, CD4⁺ T-cells and CD19⁺ B-cells. We focused on CD4⁺ T-cell subsets to appreciate thymic output, especially on naive CD4⁺ T-cells (NTE, CD45RA⁺/RO^- CD4⁺ T-cells) and recent thymic emigrants (RTE, CD4⁺CD45RA⁺/RO^-/CD31⁺). Infected patients were paired with a control cohort of patients with identical transplantation characteristics screened on hematological disease, AHCT conditioning, primary graft-versus-host disease (GHVD) prophylaxis, graft type, sex, age, and season at the AHCT and data concerning immunological reconstitution were compared.

RESULTS

At onset of nocardiosis, circulating lymphocytes and CD4⁺ T-cells means count were respectively 730/μL and 162/μL. CD8⁺ T-cells, CD56⁺ NK cells and CD19⁺ B-cells means count were respectively 362/μL, 160/μL, 112/μL. CD4⁺ T-cells subpopulations, naïve CD4⁺ T-cells production was impaired with NTE and RTE means count at 26/μL and 11/μL respectively. Comparison between nocardiosis cohort and control cohort over time highlight significant lower cellular count for lymphocytes, CD4⁺ T-cells, NTE and RTE with p = 0.001, p < 0.001, p < 0.001, p < 0.001 respectively.

CONCLUSION

Immune recovery monitoring follow-up after AHCT is of particular importance to identify patients susceptible to develop Nocardiosis. Efficient microbiological investigations toward Nocardia such PCR should be used in case of compatible clinical presentation.

Increased levels of circulating platelet-derived microparticles are associated with metastatic cutaneous melanoma

We investigated the plasma levels of PMPs in patients with 45 stage III and 45 stage IV melanoma. PMPs were characterised by flow cytometry and their thrombogenic activity. We also investigated the link between PMPs circulating levels and tumor burden. The circulating levels of PMPs were significantly higher in stage IV (8500 μL^-1 ) than in patients with stage III (2041 μL^-1 ) melanoma (P=.0001). We calculated a highly specific (93.3%) and predictive (91.7%) cut-off value (5311 μL^-1 ) allowing the distinction between high-risk stage III and metastatic stage IV melanoma. The thrombogenic activity of PMPs was significantly higher in patients with stage IV melanoma (clotting time: 40.7 second vs 65 second, P=.0001). There was no significant association between the radiological tumoral syndrome and the plasma level of PMPs. Our data suggest the role of PMPs in metastatic progression of melanoma.

In vivo and in vitro sensitivity of blastic plasmacytoid dendritic cell neoplasm to SL-401, an interleukin-3 receptor targeted biologic agent

Blastic plasmacytoid dendritic cell neoplasm is an aggressive malignancy derived from plasmacytoid dendritic cells. There is currently no accepted standard of care for treating this neoplasm, and therapeutic strategies have never been prospectively evaluated. Since blastic plasmacytoid dendritic cell neoplasm cells express high levels of interleukin-3 receptor α chain (IL3-Rα or CD123), antitumor effects of the interleukin-3 receptor-targeted drug SL-401 against blastic plasmacytoid dendritic cell neoplasm were evaluated in vitro and in vivo. The cytotoxicity of SL-401 was assessed in patient-derived blastic plasmacytoid dendritic cell neoplasm cell lines (CAL-1 and GEN2.2) and in primary blastic plasmacytoid dendritic cell neoplasm cells isolated from 12 patients using flow cytometry and an in vitro cytotoxicity assay. The cytotoxic effects of SL-401 were compared to those of several relevant cytotoxic agents. SL-401 exhibited a robust cytotoxicity against blastic plasmacytoid dendritic cell neoplasm cells in a dose-dependent manner. Additionally, the cytotoxic effects of SL-401 were observed at substantially lower concentrations than those achieved in clinical trials to date. Survival of mice inoculated with a blastic plasmacytoid dendritic cell neoplasm cell line and treated with a single cycle of SL-401 was significantly longer than that of untreated controls (median survival, 58 versus 17 days, P<0.001). These findings indicate that blastic plasmacytoid dendritic cell neoplasm cells are highly sensitive to SL-401, and support further evaluation of SL-401 in patients suffering from blastic plasmacytoid dendritic cell neoplasm.

Increased levels of circulating microparticles are associated with increased procoagulant activity in patients with cutaneous malignant melanoma

Microparticles (MPs) are known to be increased in various malignancies and are involved in tumor invasion, angiogenesis, coagulation, and metastasis. We investigated the plasma levels of annexin-V MPs (AV(+)MPs), platelet-derived MPs (PMPs), and endothelial-derived MPs (EMPs) in patients with melanoma (n=129) and in healthy controls (n=49). A functional coagulation test STA Procoag-PPL measuring the clotting time was performed on samples containing MPs to evaluate their procoagulant potential. The plasma levels of PMPs, EMPs, and AV(+)MPs were significantly higher, and the clotting time-PPL was significantly lower in melanoma patients than in healthy controls. The plasma levels of PMPs, EMPs, and AV(+)MPs were higher in stage IV than in the other stages of melanoma, but with no significant difference. In addition, we observed an inverse correlation between PMPs, AV(+)MPs, and clotting times. Our data suggest that MPs are involved in the progression of melanoma and may be associated to melanoma-associated thrombogenesis.

Phosphatidylserine-expressing cell by-products in transfusion: A pro-inflammatory or an anti-inflammatory effect?

Labile blood products contain phosphatidylserine-expressing cell dusts, including apoptotic cells and microparticles. These cell by-products are produced during blood product process or storage and derived from the cells of interest that exert a therapeutic effect (red blood cells or platelets). Alternatively, phosphatidylserine-expressing cell dusts may also derived from contaminating cells, such as leukocytes, or may be already present in plasma, such as platelet-derived microparticles. These cell by-products present in labile blood products can be responsible for transfusion-induced immunomodulation leading to either transfusion-related acute lung injury (TRALI) or increased occurrence of post-transfusion infections or cancer relapse. In this review, we report data from the literature and our laboratory dealing with interactions between antigen-presenting cells and phosphatidylserine-expressing cell dusts, including apoptotic leukocytes and blood cell-derived microparticles. Then, we discuss how these phosphatidylserine-expressing cell by-products may influence transfusion.

Extended diagnostic criteria for plasmacytoid dendritic cell leukaemia

The diagnosis of plasmacytoid dendritic cell leukaemia (pDCL) is based on the immunophenotypic profile: CD4(+) CD56(+) lineage(neg) CD45RA(+)/RO(neg) CD11c(neg) CD116(low) CD123(+) CD34(neg) CD36(+) HLA-DR(+). Several studies have reported pDCL cases that do not express this exact profile or expressing some lineage antigens that could thus be misdiagnosed. This study aimed to validate pDCL-specific markers for diagnosis by flow-cytometry or quantitative reverse transcription polymerase chain reaction on bone marrow samples. Expression of markers previously found in normal pDC was analysed in 16 pDCL, four pDCL presenting an atypical phenotype (apDCL) and 113 non-pDC - lymphoid or myeloid - acute leukaemia. CD123 was expressed at significantly higher levels in pDCL and apDCL. BDCA-2 was expressed on 12/16 pDCL and on 2/4 apDCL, but was never detected in the 113 non-pDC acute leukaemia cases. BDCA-4 expression was found on 13/16 pDCL, but also in 12% of non-pDC acute leukaemia. High levels of LILRA4 and TCL1A transcripts distinguished pDCL and apDCL from all other acute leukaemia (except B-cell acute lymphoblastic leukaemia for TCL1A). We thus propose a diagnosis strategy, scoring first the CD4(+) CD56(+/-) MPO(neg) cCD3(neg) cCD79a(neg) CD11c(neg) profile and then the CD123(high), BDCA-2 and BDCA-4 expression. Atypical pDCL can be also identified this way and non-pDC acute leukaemia excluded: this scoring strategy is useful for diagnosing pDCL and apDCL.

Natural killer cells prevent CD28-mediated Foxp3 transcription in CD4+CD25- T lymphocytes

OBJECTIVE

CD4(+)CD25(+) regulatory T lymphocytes (Treg) have been initially shown to prevent organ-specific autoimmunity. It is now accepted that Treg homeostasis depends in part on the peripheral conversion of naïve CD4(+)CD25(-) T cells. This conversion implicates acquisition of the Treg-specific markers, forkhead winged helix protein 3 (Foxp3), after CD28 costimulation. Because natural killer cells (NK) are critical for efficient cytotoxic T-cell priming and TH1 polarization, we investigated their role in Foxp3 induction in CD4(+) T lymphocytes.

MATERIALS AND METHODS

Human CD4(+)CD25(-) T lymphocytes were activated in vitro by CD28 costimulation in the presence of interleukin-2-activated NK. Three days after initial activation, Foxp3 protein and RNA expression were determined by flow cytometry and reverse transcription polymerase chain reaction. In vivo influence of activated NK on Foxp3 expression was studied in an adoptive transfer model of CD45.2(+) CD4(+)CD25(-) lymphocytes into CD45.1(+) mice.

RESULTS

Interleukin-2-activated NK decreased Treg conversion of adoptively transferred murine CD4(+)CD25(-) T cells in vivo. Likewise, human-activated NK, but not resting NK, decreased CD28-driven Foxp3 expression in CD4(+)CD25(-) T lymphocytes, while at the same time increasing proliferation and interferon-gamma (IFN-gamma) production. Neutralization of IFN-gamma partially restored Treg conversion and prevented TH1 polarization after CD28 costimulation.

CONCLUSION

The current study suggests that activated NK interfere with CD28-mediated Foxp3 expression in CD4(+)CD25(-) T lymphocytes. Our experiments further underline a molecular interaction between IFN-gamma and Foxp3 downstream of CD28 signaling. Together, these results demonstrate that activated NK play a critical role at the initiation step of immune responses by modulating peripheral Treg differentiation.

Intravenous apoptotic spleen cell infusion induces a TGF-beta-dependent regulatory T-cell expansion

Apoptotic leukocytes are endowed with immunomodulatory properties that can be used to enhance hematopoietic engraftment and prevent graft-versus-host disease (GvHD). This apoptotic cell-induced tolerogenic effect is mediated by host macrophages and not recipient dendritic cells or donor phagocytes present in the bone marrow graft as evidenced by selective cell depletion and trafficking experiments. Furthermore, apoptotic cell infusion is associated with TGF-beta-dependent donor CD4+CD25+ T-cell expansion. Such cells have a regulatory phenotype (CD62L(high) and intracellular CTLA-4+), express high levels of forkhead-box transcription factor p3 (Foxp3) mRNA and exert ex vivo suppressive activity through a cell-to-cell contact mechanism. In vivo CD25 depletion after apoptotic cell infusion prevents the apoptotic cell-induced beneficial effects on engraftment and GvHD occurrence. This highlights the role of regulatory T cells in the tolerogenic effect of apoptotic cell infusion. This novel association between apoptosis and regulatory T-cell expansion may also contribute to preventing deleterious autoimmune responses during normal turnover.

Expression of the myeloid-associated marker CD33 is not an exclusive factor for leukemic plasmacytoid dendritic cells

A new entity of acute leukemia coexpressing CD4(+)CD56(+) markers without any other lineage-specific markers has been identified recently as arising from lymphoid-related plasmacytoid dendritic cells (pDCs). In our laboratory, cells from a patient with such CD4(+)CD56(+) lineage-negative leukemia were unexpectedly found to also express the myeloid marker CD33. To confirm the diagnosis of pDC leukemia despite the CD33 expression, we demonstrated that the leukemic cells indeed exhibited pDC phenotypic and functional properties. In 7 of 8 other patients with CD4(+)CD56(+) pDC malignancies, we were able to confirm that the tumor cells expressed CD33 although with variable expression levels. CD33 expression was shown by flow cytometry, reverse transcriptase-polymerase chain reaction, and immunoblot analysis. Furthermore, CD33 monoclonal antibody stimulation of purified CD4(+)CD56(+) leukemic cells led to cytokine secretion, thus confirming the presence of a functional CD33 on these leukemic cells. Moreover, we found that circulating pDCs in healthy individuals also weakly express CD33. Overall, our results demonstrate that the expression of CD33 on CD4(+)CD56(+) lineage-negative cells should not exclude the diagnosis of pDC leukemia and underline that pDC-specific markers should be used at diagnosis for CD4(+)CD56(+) malignancies.

Triazinic herbicide determination by gas chromatography-mass spectrometry in breast milk

A solid-phase extraction procedure using a graphitized carbon black cartridge for extraction and cleaning of a series of five triazines (atrazine, deethylatrazine, deisopropylatrazine, ametryne and prometryne) from breast milk samples was developed. Using a chemometric methodology, the optimisation of both the analysis time and the triazinic herbicide separation by gas chromatography-mass spectrometry (GC-MS) was then carried out with only 18 experiments. Detection and quantification limits for 1ml breast milk sample were, respectively, 0.3 and 1 ppb for each studied compound. The variation coefficients were less than 5% over the concentration range from 1 to 100 ppb. The accuracy was between 98.63 and 104.62% for each triazinic herbicide. The recovery was between 58.64 and 63.22% for the concentration range from 1 to 100 ppb for each triazinic herbicide. The assay was successfully applied to the analysis of several breast milk samples.

Can tolerogenic dendritic cells help to modulate allo-immune responses in the setting of hematopoietic cell transplantation?

Recent evidence suggests that recipient as well as donor dendritic cell (DC) subsets are implicated in hematopoietic engraftment, graft-vs.-host disease occurrence, immune reconstitution and graft-vs.-leukemia effects observed after allogeneic hematopoietic cell transplantation. Although further data are needed to better understand the precise role of different DC subsets, strategies based on their manipulation to obtain tolerogenic DC can be envisaged. Here, we propose that DC blocked in an immature stage, using immunosuppressive agents, or lymphoid DC can be adequate candidates to control the alloreactive conflict post-allograft.

New sensitive method for the measurement of lysozyme and lactoferrin to explore mucosal innate immunity. Part II: time-resolved immunofluorometric assay used in HIV patients with oral candidiasis

The aim of this study was to explore lysozyme and lactoferrin concentrations in human immunodeficiency virus (HIV)-infected patients with oropharyngeal candidiasis (OPC). These proteins were measured by time-resolved immunofluorometric assay, validated in Part I of this study, in paired serum and salivary secretions of 30 patients. Eleven HIV-positive patients without OPC, eight HIV-positive patients with OPC and eleven HIV-negative healthy subjects were included in the study. The relative coefficient of excretion of salivary albumin was used to establish protein origin. In serum, the low lactoferrin concentrations in HIV-infected patients with and without OPC (0.610 mg/l (p < 0.05) and 0.896 mg/l (p < 0.01) vs. 1.439 mg/l in healthy subjects) were probably due to a decrease in nonspecific immunity, particularly the polymorphonuclear cells. In HIV-infected patients with OPC, the high salivary lysozyme and lactoferrin concentrations (170.94 mg/l and 66.48 mg/l vs. 23.35 mg/l and 10.20 mg/l in healthy subjects, respectively) and their mean relative coefficient of excretion of above 1 indicated a high local production of lysozyme and lactoferrin in saliva. The development of OPC in HIV-infected patients could be a consequence of inefficient lysozyme and lactoferrin concentrations and of decreased cooperation between innate and adaptative immune systems.

New sensitive method for the measurement of lysozyme and lactoferrin for the assessment of innate mucosal immunity. part I: time-resolved immunofluorometric assay in serum and mucosal secretions

Mucous peristalsis, mucus and immunity proteins, such as lysozyme and lactoferrin, are part of humoral innate immunity. The aim of this study was to develop a quantitative method, a time-resolved-immunofluorometric assay, to measure lysozyme and lactoferrin in sera, saliva, stools and cervico-vaginal secretions. This method was validated in 51 healthy subjects. Linearity for lysozyme was between 1.02 and 25 microg/l and for lactoferrin between 1.02 and 100 microg/l. The detection limit was 0.5 microg/l for lysozyme and 1 microg/l for lactoferrin. Albumin and alpha1-antitrypsin were measured by immuno-nephelometry to calculate salivary, intestinal and cervico-vaginal coefficients of excretion. Lysozyme and lactoferrin were present in all types of mucosal surfaces. Very high concentrations of lysozyme and lactoferrin were found in cervico-vaginal fluid (166.2 and 72.7 mg/l, respectively), compared to the concentrations found in the other mucosal fluids. Lysozyme in stools was produced at the rate of 0.42 mg/d compared to 0.02 mg/d lactoferrin production. Lysozyme and lactoferrin greatly exceeded the values expected from the molecular weight-affected seepage from plasma, suggesting primarily local synthesis in healthy subjects. Quantitative measurement of lysozyme and lactoferrin can aid in the assessment of the activity of mucus-associated lymphoid tissues in innate immunity, and can help in further understanding of the role of these proteins in mucosal diseases.

TP53 polymorphism at exon 4 in caucasian women from eastern France: lack of correlation with HPV status and grade of cervical precancerous lesions

OBJECTIVE

To investigate the codon 72 TP53 polymorphism in women from eastern France with normal or abnormal cervical cytology.

STUDY DESIGN

We analyzed the TP53 allele distribution by denaturant gradient gel electrophoresis assay and the human papillomaviruses (HPV) infection in 138 cervical smears: 50 normal, 20 atypical squamous cells of undetermined significance, 40 low grade squamous intraepithelial lesions, 28 high grade squamous intraepithelial lesions.

RESULTS

The viral DNA prevalence increased with cytological abnormalities. The rates of arginine (Arg) and proline (Pro) homozygosity and Arg/Pro heterozygosity were 49, 0.72, and 51%, respectively. No association was found between HPV status and TP53 polymorphism. No differences were observed in the frequency of the TP53 genotypes according to cytology.

CONCLUSION

The TP53 Arg/Arg genotype does not appear to represent a risk factor in the progression of HPV associated cervical lesions. We were not able to confirm that the TP53 genotype increases the susceptibility to be infected by HPV or to develop HGSIL, and a fortiori invasive carcinoma of the cervix.

[Immunity of the female genital tract mucosa and mechanisms of papillomavirus evasion]

Human papillomaviruses (HPV) are responsible for many cutaneous and mucosal lesions. Some viral genotypes are considered to be the causal agents of cervical cancer. Natural genital HPV infection seems to be poorly immunogenic because of its nonproductive and noninflammatory characteristics and also because of the different mechanisms developed by the virus to counteract the immune response. Knowledge of the immune system organization and its regulation in the human female genital tract needs to be clarified. It is mostly "programmed" to ensure a humoral response. Nevertheless, secretory IgA, that are particularly efficient for anti-infectious mucosal immunity are poorly present in physiological vaginal secretions. These distinctive features could explain part of the relative immune deficiency against HPV. Moreover, reduction or loss of MCH1 molecules and a defect in antigen presentation to cytotoxic lymphocytes could in part explain the cytotoxicity deficiency. There is however clear evidence that cellular immune response plays a major role in the control and course of HPV infection. This response varies according to the grade of the lesion and to the oncogenic potential of the infecting HPV. A deficiency in induction of cellular cytotoxicity mechanisms seems to be involved in the persistence of HPV infection and so in carcinogenesis. Finally, worldwide cervical cancer incidence (5000000 new cases per year) warrants effective vaccine developments. Two strategies, one preventive and one therapeutic, are now under study. Vaccine adjustments are based first on humoral immunity induction with production of neutralizing antibodies for prophylaxis and second on cellular immunity induction to kill cells with viral oncoprotein expression for therapy.

[Immunomodulator structure-activity relationships: contribution of molecular modeling]

Molecular modeling used to compare 64 immunostimulant compounds with pyrrolie quinolein or purine nuclei has pointed out that a common spatial structure is found in most of the active compounds. An additional study of immunostimulants (levamisole, muramyldipeptide) or immunosuppressive molecules (rapamycin) was performed. A common pharmacophore was found on every studied compound. It was composed of three neighboring electroattractive atoms and a further fourth atom. The favorable conformation of rapamycin for immunosuppressive action, which is not the more stable conformation, could explain the loss of its activity, or those of related macrolides, when some minor chemical modifications are tested. These findings validate the proposed concept and provide a view of the mechanism of action of most of the immunomodulator compounds for preparing novel compounds

Effect of an auditory stress on peritoneal and alveolar cells in C57 BL/6J mice of advanced age

The aim of this study was to analyse the effects of auditory stress on peritoneal and alveolar macrophages in C57 BL/6J mice of advanced age, and to compare the results to those obtained in old mice submitted to a sham stress, and to those observed in young mice submitted to the same auditory stress. We used a chemiluminescence assay to measure the production of free oxygen radicals (FOR) by macrophages. Eight 22 month-old mice were exposed to a sound stress of 110 dB for three consecutive nights; nine were submitted to a sham stress. The results were compared to those obtained in young (8 week-old) mice, 21 submitted to noise stress, and 17 controls. The corticosterone level was not increased after stress in any group. FOR production in old mice was significantly higher than that in young mice. Stress did not induce significant changes in FOR production by alveolar cells in young mice; however, the FOR production by alveolar cells was significantly higher in the stressed group than in the control group of old mice. These results show that noise stress is associated with modifications of macrophage functions that are influenced by cell localization, the behaviour of alveolar and peritoneal macrophages of old mice being clearly different in our experimental model.

Genital human papillomavirus infection among women recruited for routine cervical cancer screening or for colposcopy determined by Hybrid Capture II and polymerase chain reaction

The purpose of this study was to evaluate the clinical use of the Hybrid Capture (HC)-II system for the detection of human papillomavirus (HPV) DNA to identify women at risk of progression to high grade squamous intraepithelial lesions (HGSIL) and carcinomas by differentiating low risk (LR) HPV types (6, 11, 42, 43, 44) and high/intermediate risk (HR) HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68). Five hundred and ninety-six women were enrolled in the study. Among them, 466 attended the hospital for routine cytologic screening and 130 were referred for colposcopy because of an abnormal Pap smear. The presence of HPV DNA was tested in cervical samples collected with the Digene Cervical Sampler in Digene Specimen Transport Medium (Digene Corporation, Silver Spring, MD, U.S.A.) using the HC-II assay. Results were compared with those obtained by polymerase chain reaction (PCR) using the MY09-MY11 primers followed by several hybridizations with specific probes. The overall HPV positivity was 32.9% by HC-II and 37.8% by PCR. Among cytologically normal smears, 19.5% were positive by HC-II (14.3% HR) and 25.1% by PCR. Of the atypical squamous cells of undetermined significance samples, 52.9% were positive by HC-II (41.1% HR) and 55.9% by PCR. Of the low grade SIL, 64.5% were positive by HC-II (59.4% HR) and 68.7% by PCR. The HPV positivity rate was found identical by both techniques in high grade smears (81.6%) and squamous cervical carcinomas (100%). By using PCR as the reference method, the sensitivity of HC-II was higher among women with abnormal cytology than with normal cytology (87.3% vs. 70%). Specificity was 80.8% and 97.5%, respectively. In summary, these results indicate that the HC-II method and MY-PCR identified nearly equivalent prevalences of HPV in cervical smear specimens.

[Biology of the papillomavirus infections: V. Vaccine developments]

Several genotypes of human papillomaviruses (HPV) are recognised as aetiologic factors for cervical cancer, and viral DNA account for more 99% of cases. Thus, prevention of HPV infection by, for example, types 16 and 18, should reduce the world-wide incidence of cervical cancer. Many strategies are being developed for the control of HPV-associated lesions of the uterine cervix: prophylactic vaccines which elicit neutralizing antibodies to prevent HPV infection, and therapeutic vaccines which induce a T-cytotoxic response to early viral oncoproteins. Experimental trials are being conducted to test mucosal immunization with an ideal antigen delivery system. Vaccination strategies elicit a protective antibody response in animal species, but in humans, strategies which are likely to be effective in the control of HPV-associated preneoplastic and neoplastic lesions of the uterine cervix are still under investigation.

[Biology of papillomavirus infections. IV. Sero-epidemiological data]

Serological assays using synthetic peptides or recombinant proteins to identify specific HPV infection either fail to correlate with the type of infection or are only able to identify a small percentage of infected individuals. But genetically engineered Virus Like Particles (VLP) seem useful to develop Elisas for serological diagnosis of HPV infection and antibodies to VLP appear to correlate well with HPV DNA presence. The levels of secretory immunoglobulins in genital secretions would provide a better indicator of HPV infection, but reproducibility and standardization of the detection methods are unresolved. The clinical relevance of serologic responses is still questionable, since frequency and titer of several types of antibodies generated against HPV show a great variability which is dependent on the HPV type specificity, on the recognized epitopes and on the type of samples. However the detection of neutralizing antibodies associated with disease recurrence and antibodies raised against HPV16 E6 and E7 peptides found to react with sera of cancer patients, needs to pay attention.

[The biology of papillomavirus infections. III. Immune response]

Infection with the human papillomaviruses, especially with oncogenic HPVs increases the risk for development of precancerous and cancerous lesions of the cervix. The immune response of the host is likely to be an important factor in determining regression or progression of papillomaviruses-associated lesions. Systemic IgG and IgA response is classically associated with current or past papillomavirus infections. A deficiency in local cellular immune response is however frequently observed and linked to a decrease of cytokine synthesis by infected cells, a reduction or loss of MCH I molecules and a defect in antigen presentation to cytotoxic T lymphocytes. Although secretory immunoglobulins are generated locally in response to papillomavirus infections, humoral immunity in the female genital reproductive tract seems to be inefficient. The papillomavirus infections would lead to a decrease in cellular immunity which could be favourable to viral latency and/or precancerous and cancerous lesion development.

Synthesis of new pyrrolo[1,2-d][1,2,4]triazines and thiazolo[3,4-d][1,2,4]triazines as immunostimulating agents

Four pyrrolo[1,2-d][1,2,4]triazines and four thiazolo[3,4-d][1,2,4]triazines were synthesized from trans-4-hydroxy-L-proline and L-thiaproline, respectively. The synthetic route involved formation of hydrazides followed by cyclization with orthoesters. The proliferative response to human lymphocyte mitogen (phytohemagglutinin) revealed significant immunostimulant activity for all test drugs. Furthermore, some triazine derivatives were effective to activate production of free oxygen radical by phagocytes in response to stimulation by opsonized zymosan.

[Serum and salivary immunoglobins A in atopic dermatitis. Prospective and comparative case control study]

IgA system has been poorly studied in patients with atopic dermatitis (AD). Previous studies have showed that a transient serum IgA deficiency in infancy could lead to atopic disease. In addition, decrease in salivary IgA has been demonstrated in patients with AD. The purpose of our work was to study the IgA system both in serum saliva in patient with AD.

PATIENTS AND METHOD

We conducted a controlled prospective study from January 1994 to May 1996. 46 patients with AD and 52 healthy volunteers matched for sex and age were included. Atopic patients fulfilled at least three major and three minor features defined by Hanifin and Rajka. None above atopic criteria were present in the control group. Saliva was collected using a small cylinder of a cotton-wool-like substance (Salivette) kept in the buccal fold. Serum and saliva samples were assayed for IgA using standard nephelometric method and time-resolved immunofluorometric assay. Secretory IgA were assayed by a sandwich-type enzyme linked immunosorbent assay. Blood eosinophils and serum IgE were also evaluated.

RESULTS

IgA and secretory IgA were detected in all serum and saliva collected. No statistically significant difference were observed in serum or in saliva for both IgA and secretory IgA between patients with AD and controls. As expected, blood eosinophils and serum IgE were significantly increased in patients with AD.

DISCUSSION

None patients (atopic or control) exhibited IgA deficiency. Although no statistically significant, a trend to higher concentrations of serum and salivary IgA was observed in patients with AD suggesting a stimulation of mucosa-associated lymphoid tissue in these patients.

Serum secretory immunoglobulins in ankylosing spondylitis

Humoral mucosal immunity may be implicated in pathophysiology of ankylosing spondylitis (AS). The aim of the study was to evaluate serum levels of IgA, IgM and secretory IgA (sIgA), secretory IgM (sIgM) as well as free secretory component (FSC) in patients with AS compared to controls and rheumatoid arthritis (RA) patients. Levels of sIgA, sIgM and FSC were measured with a specific ELISA in 37 AS patients, 45 controls and 27 RA. The results were as follows: Serum levels of IgA were higher in AS vs controls and in RA vs controls (p = 0.01). Levels of sIgA were higher in AS vs controls (p = 0.01), but higher in RA vs AS (p = 10(-4)). There was no difference of sIgM in AS vs controls, FSC levels were higher in AS vs controls, and higher in AS patients with elevated CRP. In view of elevated FSC, this increase of sIgA in AS may have been due to excessive production of mucosal IgA after bacterial stimulation according to the current hypothesis of the disease.

Function of the oxidative metabolism of phagocytes in elderly people: relationship to nutritional and inflammatory status

The purpose of this study was to investigate the phagocyte production of oxygen-free radicals (OFR) in the whole blood of elderly patients (EP), by measuring chemiluminescence at the basal state and after stimulation, and to study the relationships between its impairment, if any, and blood indices of the nutritional and inflammatory status in elderly patients with (Inf) and without (N-Inf) inflammatory diseases. The results showed that OFR production by resting circulating phagocytes, assessed by chemiluminescence on whole blood, is markedly increased in EP, irrespective of any in vitro stimulation. The significant correlation we found between basal chemiluminescence and immunoglobulins levels, IgM, IgG and IgA in the whole EP sample, and IgG in the N-Inf group, suggests that it could be linked to the cytokine imbalance that favours Th2- and impairs Th1-type of cytokine production by T-cells in EP. The basal overproduction of OFR was observed both in Inf and N-Inf EP and unexpectedly was less marked in group Inf EP. This observation suggests a relative impairment in EP phagocytic adaptive responses to inflammatory conditions. This suggestion was confirmed by the absence of significant differences between the chemiluminescence index CLI calculated after phorbol myrisate acetate (PMA) stimulation in group Inf vs. N-Inf EP, and by the lower CLI observed in group Inf phagocytes stimulated by opsonized zymosan. The role of blood changes associated with inflammation and/or nutrition in this relative impairment is supported by the positive correlations that we observed between CLI and acute-phase proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunomodulatory agents: dioxothiadiazabicyclo[3.3.0]octanes and their 2-spiro derivatives

A series of 6,8-dioxo-3-thia-1,7-diazabicyclo[3.3.0]octanes and a series of 6,8-dioxo-3-thia-1,7-diazabicyclo[3.3.0]octane 2-spiro derivatives were synthesized from L-(-)-R-cysteine ethyl ester in two steps. The synthetic route involved condensation of the amino acid with an appropriate aldehyde or ketone, then a further condensation of the resultant ethyl thiazolidine-4-carboxylate with an isocyanate or an isothiocyanate. The proliferative response to human lymphocyte mitogen (phytohemagglutinin) was used as a primary screening assay for most of the thiadiazabicyclic compounds in comparison with levamisole. Furthermore, the most active compounds were tested for ability to release soluble receptors (sRIL-2) after mitogenic stimulation of T cells and for ability to activate macrophage oxidative metabolism measured by chemiluminescence. Most compounds were active in all three tests and some showed dose-dependent activity.

Light chains of immunoglobulins in human secretions

Immunoglobulin kappa light chains are predominant in normal human serum and a kappa/lambda ratio of 1.7 to 2 has been reported. However, little is known of the partition of light chains in secretions. The levels of IgA, kappa and lambda were assayed by nephelometry in a series of secretions and in normal human serum. Although kappa chains remained predominant, the different secretions studied could be classified according to their kappa/lambda ratio. In saliva (P < 0.001), nasal fluid (P = 0.01) and tears (P = 0.04) the kappa/lambda ratio was significantly lower than in serum. Conversely, higher kappa/lambda ratios were obtained in gastric juice (P = 0.005) and hepatic bile (P = 0.004) and no significant difference was noted between serum and gall bladder bile (P = 0.62). The lower ratios were all observed in fluids produced by glands surrounded by lymphoid tissue included in the mucosae-associated lymphoid tissue. These data strengthen previous observations that suggest a preferential production of lambda chains in human mucosae.

Polymeric Ig receptor expression in hepatocellular carcinoma

The cellular localisation of the polymeric Ig receptor (pIg-R) and carcinoembryonic antigen (CEA), hepatic and biliary cell markers, were investigated in patients with hepatocellular carcinoma (HCC) and high serum levels of secretory component. Serum SC were increased 6-20-fold in 8 HCC patients compared with normal subjects. Serum free SC was positively correlated bilirubin (r = 0.95, P less than 0.04). In normal liver tissue, cytokeratin (CK) 8 and 18 were localised in hepatocytes and biliary cells while pIg-R and CK 19 expression was restricted to biliary cells. In tumoral liver tissue, malignant cells expressed CK 8 and 18 weakly; pIg-R and CK 19 were not detected in tumoral cells. CEA was expressed by biliary cells in normal and proliferating ducts. In peritumoral fibrosis, proliferating biliary cells were strongly stained by anti-cytokeratins and anti-pIg-R antibodies. In one case, pIg-R was localised in isolated cells close to fibrosis without co-staining of anti-CK 19. Thus increased serum SC is not associated with pIg-R expression by tumoral cells, and pIg-R may be considered an additional marker of biliary cells. High SC might be explained either by reflux from bile to serum and/or release of unbound SC from the vascular pole of non-functional, proliferating biliary structures.

Serum and bile secretory immunoglobulins and secretory component during the early postoperative course after liver transplantation

Secretory component was assayed in serum and bile from 34 patients within 40 days after a first or a second (three cases) liver transplantation. Levels of serum secretory IgA and IgM and of a serum component referred to as immunoreactive free secretory component, identified by its reactivity with monoclonal and polyclonal antibodies specific to secretory component, were significantly elevated in all posttransplant patients compared with 45 healthy subjects and 10 kidney transplant patients (p less than 0.0001). The highest serum levels of bound secretory component and of immunoreactive free secretory component were observed in patients with acute rejection. The elevation of immunoreactive free secretory component was significantly higher in patients with rejection as compared with patients with a graft ischemia (p = 0.002) or an uncomplicated postoperative evolution (p = 0.01). The highest levels of immunoreactive free secretory component and secretory IgM were observed in a transplant patient with selective IgA deficiency. No significant difference was seen between the levels of serum immunoreactive free secretory component observed in patients with rejection and those of patients with cytomegalovirus hepatitis or sepsis. Immunoreactive free secretory component, secretory IgA and secretory IgM levels measured in the serum of three patients with primary nonfunction were lower than those observed in the other groups. Immunoreactive free secretory component bile/serum ratios calculated from 16 patients were significantly higher in patients with acute rejection than in infected patients. This study provides new insight into the mechanisms of increase of serum immunoreactive free secretory component, secretory IgA and secretory IgM in various types of liver dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)

Gall bladder: the predominant source of bile IgA in man?

The sedimentation profiles of IgA and Secretory Component (SC) and the concentrations of IgA, IgG, IgM, SC and albumin were evaluated after an overnight fast in gall bladder bile of six adult subjects without hepatobiliary disease. The sedimentation profiles differed from those previously obtained in hepatic bile in three ways: gall bladder bile contained a greater percentage of free-SC, a greater percentage of polymeric-IgA (p-IgA), and a major peak of 14 to 19 S p-IgA associated to SC. In contrast to hepatic bile in which IgG is the predominant Ig, IgA clearly was the predominant Ig in gall-bladder bile, its concentration averaging 92 micrograms/ml. Relative-to-albumin coefficients of excretion of proteins in gall bladder bile averaged 0.99 for IgG, 8.6 for monomeric IgA, 196 for p-IgA and 31 for IgM, indicating that there was a selective excretion of IgA and IgM into gall bladder bile. As compared to hepatic bile, the enrichment of gall bladder bile with IgA and IgM was respectively 6.5 and 11.5 times greater than with IgG. These results suggest that quite a significant amount of p-IgA could have been added to bile during its storage in the gall bladder which should therefore be regarded as the predominant source of bile IgA in humans.