Generation and characterization of cytochrome P450 3A74 CRISPR/Cas9 knockout bovine foetal hepatocyte cell line (BFH12)

In human, the cytochrome P450 3A (CYP3A) subfamily of drug-metabolizing enzymes (DMEs) is responsible for a significant number of phase I reactions, with the CYP3A4 isoform superintending the hepatic and intestinal metabolism of diverse endobiotic and xenobiotic compounds. The CYP3A4-dependent bioactivation of chemicals may result in hepatotoxicity and trigger carcinogenesis. In cattle, four CYP3A genes (CYP3A74, CYP3A76, CYP3A28 and CYP3A24) have been identified. Despite cattle being daily exposed to xenobiotics (e.g., mycotoxins, food additives, drugs and pesticides), the existing knowledge about the contribution of CYP3A in bovine hepatic metabolism is still incomplete. Nowadays, CRISPR/Cas9 mediated knockout (KO) is a valuable method to generate in vivo and in vitro models for studying the metabolism of xenobiotics. In the present study, we successfully performed CRISPR/Cas9-mediated KO of bovine CYP3A74, human CYP3A4-like, in a bovine foetal hepatocyte cell line (BFH12). After clonal expansion and selection, CYP3A74 ablation was confirmed at the DNA, mRNA, and protein level. The subsequent characterization of the CYP3A74 KO clone highlighted significant transcriptomic changes (RNA-sequencing) associated with the regulation of cell cycle and proliferation, immune and inflammatory response, as well as metabolic processes. Overall, this study successfully developed a new CYP3A74 KO in vitro model by using CRISPR/Cas9 technology, which represents a novel resource for xenobiotic metabolism studies in cattle. Furthermore, the transcriptomic analysis suggests a key role of CYP3A74 in bovine hepatocyte cell cycle regulation and metabolic homeostasis.

Establishment and characterization of cytochrome P450 1A1 CRISPR/Cas9 Knockout Bovine Foetal Hepatocyte Cell Line (BFH12)

The cytochrome P450 1A (CYP1A) subfamily of xenobiotic metabolizing enzymes (XMEs) consists of two different isoforms, namely CYP1A1 and CYP1A2, which are highly conserved among species. These two isoenzymes are involved in the biotransformation of many endogenous compounds as well as in the bioactivation of several xenobiotics into carcinogenic derivatives, thereby increasing the risk of tumour development. Cattle (Bos taurus) are one of the most important food-producing animal species, being a significant source of nutrition worldwide. Despite daily exposure to xenobiotics, data on the contribution of CYP1A to bovine hepatic metabolism are still scarce. The CRISPR/Cas9-mediated knockout (KO) is a useful method for generating in vivo and in vitro models for studying xenobiotic biotransformations. In this study, we applied the ribonucleoprotein (RNP)-complex approach to successfully obtain the KO of CYP1A1 in a bovine foetal hepatocyte cell line (BFH12). After clonal expansion and selection, CYP1A1 excision was confirmed at the DNA, mRNA and protein level. Therefore, RNA-seq analysis revealed significant transcriptomic changes associated with cell cycle regulation, proliferation, and detoxification processes as well as on iron, lipid and mitochondrial homeostasis. Altogether, this study successfully generates a new bovine CYP1A1 KO in vitro model, representing a valuable resource for xenobiotic metabolism studies in this important farm animal species.

Three-dimensional computational model of a blood oxygenator reconstructed from micro-CT scans

Cardiopulmonary bypass procedures are one of the most common operations and blood oxygenators are the centre piece for the heart-lung machines. Blood oxygenators have been tested as entire devices but intricate details on the flow field inside the oxygenators remain unknown. In this study, a novel method is presented to analyse the flow field inside oxygenators based on micro Computed Tomography (μCT) scans. Two Hollow Fibre Membrane (HFM) oxygenator prototypes were scanned and three-dimensional full scale models that capture the device-specific fibre distributions are set up for computational fluid dynamics analysis. The blood flow through the oxygenator is modelled as a non-Newtonian fluid. The results were compared against the flow solution through an ideal fibre distribution and show the importance of a uniform distribution of fibres and that the oxygenators analysed are not susceptible to flow directionality as mass flow versus area remain the same. However the pressure drop across the oxygenator is dependent on flow rate and direction. By comparing residence time of blood against the time frame to fully saturate blood with oxygen we highlight the potential of this method as design optimisation tool. In conclusion, image-based reconstruction is found to be a feasible route to assess oxygenator performance through flow modelling. It offers the possibility to review a product as manufactured rather than as designed, which is a valuable insight as a precursor to the approval processes. Finally, the flow analysis presented may be extended, at computational cost, to include species transport in further studies.

Implementation of epidural analgesia for labor: is the standard of effective analgesia reachable in all women? An audit of two years

BACKGROUND

Social and cultural factors combined with little information may prevent the diffusion of epidural analgesia for pain relief during childbirth. The present study was launched contemporarily to the implementation of analgesia for labor in our Department in order to perform a 2 years audit on its use. The goal is to evaluate the epidural acceptance and penetration into hospital practice by women and care givers and safety and efficacy during childbirth.

PATIENTS AND METHODS

This audit cycle measured epidural analgesia performance against 4 standards: (1) Implementation of epidural analgesia for labor to all patients; (2) Acceptance and good satisfaction level reported by patients and caregivers. (3) Effectiveness of labor analgesia; (4) No maternal or fetal side effects.

RESULTS

During the audit period epidural analgesia increased from 15.5% of all labors in the first trimester of the study to 51% in the last trimester (p < 0.005). Satisfaction levels reported by patients and care givers were good. A hierarchical clustering analysis identified two clusters based on VAS (Visual Analogue Scale) time course: in 226 patients (cluster 1) VAS decreased from 8.5±1.4 before to 4.1±1.3 after epidural analgesia; in 1002 patients (cluster 2) VAS decreased from 8.12±1.7 before (NS vs cluster 1), to 0.76±0.79 after (p < 0.001 vs before and vs cluster 2 after). No other differences between clusters were observed.

CONCLUSIONS

Present audit shows that the process of implementation of labor analgesia was quick, successful and safe, notwithstanding the identification of one cluster of women with suboptimal response to epidural analgesia that need to be further studies, overall pregnant womens'adhesion to labor analgesia was satisfactory.

Reweaving the social fabric: antecedents of social support facilitation

Contemporary society leaves many individuals without a continuing support group. Continued integration into a network of supportive social relationships is demonstrably related to the prevention of breakdown in health in the widest variety of mental and physical forms. Yet the task of assuring continuity of supportive relationships has not been central to any professional discipline. The facilitation of social support is likely to become more central to community health education.To address this issue we examine seven different forms of intervention which address the problem of augmenting supportive relationships. The goal is to extract the essence of the professional role in the provision of social support and to suggest its relevance to community health education.

Risk factors for inflammatory bowel diseases according to the "hygiene hypothesis": a case-control, multi-centre, prospective study in Southern Italy

BACKGROUND

Ulcerative colitis (UC) and Crohn's disease (CD) are inflammatory bowel diseases (IBD) of unknown aetiology. The 'hygiene hypothesis' (HH) suggests that several hygiene-related factors may have contributed to the increased incidence of IBD. The aim of the study was to evaluate risk factors for IBD related to HH in a cohort of IBD patients from the south of Italy.

METHODS

We prospectively performed a one-year, questionnaire-based, case-control, multi-centre study focusing on the principal risk factors for IBD according to HH. We investigated the main surrogate markers of HH (helmintic infections and antibiotics in childhood; breastfeeding; family size/sibship;urban upbringing; personal and domestic hygiene in childhood) in UC and CD patients, in comparison with a control group of healthy subjects. In addition, the traditional risk factors for IBD were also recorded.

RESULTS

The study population included 527 cases of UC, 468 CD and 562 controls. None of the surrogate risk factors of HH was significantly associated with IBD. On the contrary, the traditional risk factors confirmed their statistical significance in this IBD population. Familial aggregation: OR 4.07 for UC; OR 4.83 for CD; smoking: OR 0.38 for UC; OR 1.40 for CD; appendectomy: OR 0.28 for UC; OR 1.61 for CD.

CONCLUSION

Even though risk factors associated to the HH have been proposed as a possible explanation for the increasing calendar trend of IBD incidence, their role does not appear to be statistically significant. Familial aggregation, smoking habits and appendectomy still remain the main risk factors associated with IBD.

Functional antagonism between IL-2 and PGA1 or PGJ2 in the control of proliferation of human cord blood-derived mononuclear cells

Cyclopentenone prostaglandins PGA1 and PGJ2 induce growth arrest at the G1/S interphase of the cell cycle in tumour cell lines. Notably, PGE, the precursor molecule of PGA, downregulates the interleukin (IL)-2-dependent proliferation of lymphocytes. Therefore the IL-2/IL-2 receptor system and relative signal transduction is a possible target of the antiproliferative effect of PGA/PGJ. In the present study the PGA1/PGJ2-dependent growth inhibition of IL-2-stimulated primary human cord blood mononuclear cells (CBMCs) was found to be mediated by interference with the IL-2 proliferative signal. Both prostaglandins (PGs) inhibited the synthesis of total RNA and protein in IL-2 stimulated cells. PGA1 and even more PGJ2 downregulated the expression of IL-2 receptor alpha (CD25 phenotype). IL-2 partly reversed this effect. Moreover, suppression of IL-2-stimulated cells was not the result of PG-mediated activation of apoptosis. On the contrary, PGs reduced both apoptosis and the high expression of c-Jun detectable in CBMCs spontaneously. Cyclin A/Cdk2 complexes regulate G1/S transition during the cell cycle. In IL-2-stimulated cells, the levels of Cdk2 were found to be lower in PG-treated cells than those detected in controls. In conclusion, cyclopentenone PGs inhibit CBMCs spontaneous or IL-2-dependent proliferation in part by interfering with the IL-2 pathway.

Prostaglandin E2 induces apoptosis in resting immature and mature human lymphocytes: a c-Myc-dependent and Bcl-2-independent associated pathway

Prostaglandin E2 (PGE2) is a known negative regulator of T lymphocyte proliferation. Previously we have indirectly evidentiated the involvement of PGE2 in apoptosis of lymphocytes both in vitro and in vivo. We have evaluated a possible direct effect of PGE2 on apoptosis. To this end we have investigated the in vitro effects of PGE2 on cell death, and its possible correlation with c-Myc and Bcl-2 proteins. We used freshly isolated unstimulated human lymphocytes from neonatal thymus, cord blood and adult peripheral blood. PGE2 induced DNA fragmentation in both peripheral and cord blood at 10(-7) to 10(-5) M concentrations, even though this induction was delayed in peripheral blood with respect to cord blood. Apoptosis induced by PGE2 was always associated with a dose-dependent increase of cellular steady state c-Myc protein levels, whereas Bcl-2 protein levels were not substantially affected. Unstimulated thymocytes showed spontaneous DNA fragmentation that occurred earlier and at higher levels in PGE2-(10(-5) M) treated cells with respect to untreated controls. Also in these cells, PGE2 produced an early increase of c-Myc protein expression, although Bcl-2 protein levels remained unchanged. In conclusion, PGE2 induces apoptosis with different kinetics on immature and mature T cells: this induction is associated with the increase of c-Myc protein expression and seems to be independent from Bcl-2 regulation.

In vitro infection of leukemic bone marrow with HTLV-I generates immortalized cell lines expressing T or myeloid cell phenotype

Leukemic bone marrow cells ( > 90% blasts) of a patient with acute myeloblastic leukemia (AML), non-treated or pretreated in vitro with a mutagenic triazene compound, were infected with HTLV-I by coculture with irradiated virus-donor cells. Immortalized, HTLV-I+, double-positive CD4/CD8 euploid T cell lines, expressing HLA class I/II monomorphic determinants, and inappropriate myeloid and progenitor cell markers (ie CD13, CD14, CD15 and CD33 antigens) were obtained. In one out of 10 triazene-pretreated samples, HTLV-I infection resulted in the appearance of a rapidly growing triploid cell line (ie MTLC1 line) showing: (1) myeloid but not lymphoid phenotype; (2) beta and delta T cell receptor in germline configuration; (3) integrated, complete and incomplete HTLV-I provirus genome (also detected in a number of MTLC1 clones); (4) a high percentage of cells positive for non-specific cross-reacting antigen (a CEA-related molecule present in myeloid cells) under the influence of gamma-interferon; (5) absence of HLA class I/II antigen expression; (6) absence of tax gene transcription. Blast cell proliferation was marginal or absent when leukemic marrow was not subjected to retroviral infection. These results show that exposure of leukemic bone marrow to HTLV-I can be followed by immortalization of T and myeloid cells. Although no data are available to establish whether tax expression played a role in the early phase of the immortalization process of MTLC1 line, tax gene product was not required for maintaining long-term growth of MTLC1 cells.

HSP70 production and inhibition of cell proliferation in Molt-4 T-cells after cell-to-cell transmission of HTLV-I: effect of PGA1

Infection with HTLV-I is associated with leukemic transformation of mature CD4+ T lymphocytes. PGA1, a powerful inhibitor of tumour cell proliferation, can prevent the clonal expansion of HTLV-I-infected cells following acute infection of cord blood-derived mononuclear cells. Since the antiproliferative effect of PGA1 on HTLV-I transformed, chronically infected MT-2 cell line was associated with induction of HSP70, we have investigated the effect of PGA1 on cell cycle progression and HSP70 production in a leukemic T-cell line (Molt-4) shortly after exposure to HTLV-I in a cell-to-cell transmission model. Rate of cell proliferation and HSP70 expression were studied within one duplication cycle of Molt-4 cells after exposure to HTLV-I. Growth of both control and virus-exposed cultures was inhibited by treatment with PGA1 (4 micrograms/ml) and cell cycling was arrested preferentially at the G1/S interphase. Synthesis of HSP70 was induced within 3 h by PGA1 in control and virus-exposed Molt-4 cells and became undetectable from overnight onward, though the protein accumulated in the cells. The arrest of growth was observed from overnight up to 48 h so that treated cells almost missed one cycle. Interestingly, HSP70 transcript and protein persisted at remarkably high levels in Molt-4 cells exposed to HTLV-I in the absence of PGA1, showing that HSP70 expression can be directly activated during primary infection with this human retrovirus. Moreover, in these cocultures, treatment with PGA1 or heat shock was not able to increase further the elevated level of HSP70 found in untreated cocultures, suggesting that during the early period of the virus-transmission phase, HTLV-I could interfere with HSP70 induction by other inducers.

Cell-cycle progression and apoptosis in K562 and Molt-4 cells after cell-to-cell transmission of HTLV-I: modulation by interferons

Human T-cell leukemia virus type I (HTLV-I) is mainly propagated by cell division and therefore the virus-driven proliferation of infected cells can represent a predisposing condition to final development of adult T-cell leukemia (ATL) in vivo. To correlate virus expression and cell cycle progression of recipient cells after acute infection with HTLV-I, K562 multipotent erytholeukemia and Molt-4 T-lymphoma cells were used as recipient cells in a cell-to-cell virus transmission model. Cell cycle progression was studied by flow cytometry during one duplication cycle of recipient cells and transcription of HTLV-I was evaluated during the same time course. The antiproliferative and antiviral effects of recombinant interferons alpha, beta and gamma were also evaluated on cell cycle progression and HTLV-I expression. Transcription of HTLV-I in immortalised virus-donor MT-2 T-cells was found to be related to cell cycle. After coculturing recipient K562 or Molt-4 cells with lethally irradiated, non-dividing virus-donor MT-2 cells, progression into cell cycle of recipient cells was delayed. A pre-G(1) peak, corresponding to 6-11 % apoptotic cells, was identified in cocultured Molt-4/MT-2 cells and not in Molt-4 controls, and was not affected by treatment with IFNs. Notably, no such peak was identified either in control or in cocultured K562 cells. During this time course, transcription of the viral subgenomic mRNA encoding for the env-pX region was prevalently observed. Treatment with IFNalpha and especially with IFNbeta at the onset of the cultures inhibited the growth of both control and virus-exposed recipient cells. IFNgamma was less effective. A clearcut reduction of the percentage of cells entering the S phase was observed only after treatment with IFNbeta. At the same time, in IFNbeta-treated cocultures a marked inhibition of transcription of viral mRNA was observed, suggesting that, during acute infection, treatment with IFNbeta contributes to reduce the infection of recipient cells by down-regulating both the cellular proliferation rate and virus transcription in infected cells.

Effects of cyclopentenone prostaglandins on myeloid cells during early infection with HTLV-I. I. Cell differentiation determines sensitivity to prostaglandins and virus infection

Human myeloid cell lines at different stages of differentiation (K562, HL60 and U937) were used to analyze the permissivity of the myelomonocytic lineage to acute infection with human T-cell leukemia virus type-I (HTLV-I) after cell-to-cell transmission and to evaluate the effect of cyclopentenone prostaglandins (PG)A1 and PGJ2 on virus transmission, proliferation of recipient cells and cell-mediated cytotoxicity against virus-donor cells. Exposure to HTLV-I delayed the growth rate of recipient cells, especially in U937 cells. This effect was related to the phase of cell cycle when cells were exposed to HTLV-I. Treatment of control and virus-exposed cells with these PGs, both inducing growth arrest prevalently at the G1/S interphase of the cell cycle, inhibited cell proliferation in a concentration-dependent way. The antiproliferative effect of both PGs increased progressively from pluripotent K562 to promyelocytic HL60 and monoblastoid U937 cells, suggesting that differentiated cells were more susceptible to PG-mediated inhibition of growth than pluripotent cells. PG treatment influenced the permissivity of recipient cells to HTLV-I, with different effects on less differentiated myeloid cells in comparison with more differentiated monoblastoid cells. In fact, the percentage of cells positive for the p19gag protein was increased among PG-treated K562 or HL60 cells, although it was reduced in PG-treated U937 cells. To this respect, PGA1 was more effective on asynchronous and PGJ2 on synchronous U937 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of cyclopentenone prostaglandins on myeloid cells during early infection with HTLV-I. II. Regulation of synthesis of inducible p72 heat shock protein

Differentiation of cells of myelomonocitic lineage influences both cellular permissivity to infection with human T-cell leukemia virus type I after cell-to-cell virus transmission and sensitivity to the antiproliferative effect of cyclopentenone prostaglandins (PG)A1 and PGJ2. Growth inhibition and control of infection were found to be associated with high intracellular levels of inducible p72 heat shock protein (HSP70). Pluripotent K562 cells produced higher HSP70 base-line levels than promyelocytic HL60 or monoblastoid U937 cells. Treatment with PGA1 and especially with PGJ2 enhanced the synthesis of HSP70 in all these cells. Notably, HSP70 accumulated in virus-exposed U937 cells (but not in K562 or HL60 cells). Because in lethally irradiated virus-donor cells HSP70 production was barely detectable, expression of this protein in cocultured U937 cells can be prevalently attributed to virus-recipient cells. Treatment with PGA1 and even more with PGJ2 remarkably enhanced the synthesis of HSP70 in virus-exposed U937 cells, thus resulting in persistently high levels of HSP70 protein in the cells. As shown previously, in U937 cells treatment with PGs was associated with reduced percentages of virus p19gag positive cells and enhanced specific lysis of virus-donor cells at early time points after cell-to-cell transmission. Because the HSP70 protein family is involved in the control of cell proliferation as well as in antigen processing function during the immune response to pathogens, it is possible that persistent high expression levels of HSP70 in PG-treated cells play a critical role in regulating both cell cycling and antiviral cellular responses.

Antiproliferative activity of cyclopentenone prostaglandins in early HTLV-1 infection is independent of IL-2 and is associated with HSP70 induction

Cyclopentenone prostaglandins PGA1 and PGJ2 can inhibit the growth of HTLV-1 infected cord blood-derived human mononuclear cells (CBMC), both after acute infection and in chronically infected, immortalized cells. When CBMC were exposed to HTLV-1 infection by coculturing with lethally irradiated, virus-donor allogeneic MT-2 cells, they underwent a proliferative response, that peaked within the first week and then declined. PG treatment did not inhibit the initial proliferation (day 4) of cocultured CBMC, while multiple treatments with PGA1 and more efficiently with PGJ2, suppressed the late cell proliferation (from day 8 onward). The pharmacological effects of PGA1 and PGJ2 were reversible and therefore multiple treatments were required to maintain their antiproliferative activity. Increasing concentrations (20, 40, 80 IU/ml) of recombinant IL-2 did not affect the virus-associated proliferative response of CBMC, and exogenous IL-2 did not revert the antiproliferative effect of both PGs. Arrest of proliferation in cocultured CBMC occurred concomitantly with expression of high levels of HSP70 in the cells. In fact, though HSP70 expression was induced early (day 5) after exposure to HTLV-1, its expression was further increased after multiple PG treatments and high levels were found when the antiproliferative effect of PGs became manifest. Since HSP70 protein family is involved in the control of cell cycle as well as in antigen processing and presentation during the immune response against tumor cells and pathogens, the persistent expression of this protein in PG-treated cocultures suggested that, beside inhibiting the growth of virus-infected cells, HSP70 expression might play a role in modulating the immune function of CBMC. However, unlike in most virus infection models, in which cyclopentenone PGs exert clear antiviral effects by inhibiting the synthesis and maturation of virus proteins, no antiviral activity was found in this model of infection. This strongly suggests that the main effect of these PGs against HTLV-1 infected cells consists in inhibiting proliferation in vitro without affecting viral expression.

Protective effect of interferon beta on human T cell leukaemia virus type I infection of CD4+ T cells isolated from human cord blood

The present study shows the effect of human interferon beta (IFN beta) on the susceptibility of highly purified cord blood CD4+ T cells to infection with the human T cell leukaemia virus type I (HTLV-I). Unfractionated cord blood mononuclear cells (CBMC), or a separated CD4+ T cell subpopulation (CBCD4) were exposed to HTLV-I by cocultivation with a chronically infected virus-donor cell line. The results show that presence of proviral DNA as well as virus transcription was markedly reduced by IFN beta in both populations, indicating that this cytokine protects not only unfractionated CBMC but also purified CBCD4 cells from virus infection. Moreover IFN beta treatment caused 60%-80% inhibition of virus expression in CBCD4, assayed as the presence of virus core protein p19. This study demonstrates that IFN beta is able to inhibit HTLV-I infection of CBMC through a mechanism that does not necessarily involve cell-mediated natural or antigen-dependent immunity afforded by CBMC subpopulations distinct from targets of HTLV-I infection. Therefore it is reasonable to conclude that IFN beta has a direct protective effect on CBCD4, through induction of antiviral resistance/activity in target cells.

Combined treatments with interferon (alpha,beta) plus PGA1 to control early infection with HTLV-I in primary cord blood-derived mononuclear cells

Interferon (IFN) alpha and beta can activate an antiviral and immunomodulating response in primary cord blood-derived mononuclear cells (CBMC) exposed to infection with Human T-cell Leukemia Virus type I (HTLV-I), resulting in partial inhibition of early infection in vitro. On the other hand, PGA1, a PGE1-derived cyclopentenone prostaglandin, can inhibit in vitro the proliferation of virus-infected CBMC, preventing the emergence of the potentially transformed clone. In order to achieve a complete control of HTLV-I infection in this experimental model, we evaluated whether the antiviral activity of IFNs and the antiproliferative activity of PGA1 could be preserved in a combination therapy scheme. Recipient CBMC were treated with IFN alpha or beta (1000 IU/ml) at the onset of the co-culture with lethally irradiated virus-donor MT-2 cells, followed by multiple treatments with PGA1 (4 micrograms/ml every 4 days, starting on day 0) for 6 weeks post infection (p.i.). In PGA1-treated co-cultures the percentage of virus-positive CBMC was constantly doubled during culture time as well as the amount of viral transcripts and p19 virus core protein production were increased. The antiviral effects of IFNs, resulting in about a 50% reduction of the percentage of virus-positive CBMC and consequently in a partial inhibition of virus expression (HTLV-I transcription and p19 production) until 4 weeks p.i., were suppressed by multiple PGA1 treatments. However, the antiproliferative effect of PGA1 was enforced in IFN-treated co-cultures, leading to earlier control of proliferation of virus-infected cells. Interestingly, infection of CBMC with HTLV-I was associated with persistent expression of 70 kDa heat shock protein (HSP70), for at least 4 weeks p.i. IFNs and PGA1 showed antagonistic effects on HSP70 production in infected CBMC. In fact, production of HSP70 was suppressed (or prevented) in IFN-treated co-cultures, tested 2 and 4 weeks p.i. The fact that the expression of HSP70 is apparently suppressed (or prevented) by IFN treatment is surprising, since expression of this protein family has been associated with antiviral immunity. PGA1 could totally reverse the IFN-mediated suppression of HSP70 expression in these co-cultures. It is presently unclear whether HSP70 expression is directly involved in the control of proliferation exerted by PGA1 against virus-infected CBMC or is an epiphenomenon associated with inhibition of cell growth.

Ocular involvement correlated with age in patients affected by major and intermedia beta-thalassemia treated or not with desferrioxamine

We examined 25 patients affected from Cooley's disease and five by beta-thalassemia intermedia. The mean age was 15 +/- 6.3 years. Fifteen patients, (18 years or older) three of them affected by beta-thalassemia intermedia, presented ocular abnormalities. So it was impossible to establish a correlation between laboratory data and ocular damages; their observation, with reference to untreated beta-thalassemia subjects, suggested that ocular abnormalities cannot be only attributed to desferrioxamine treatment.

Antiviral activity of individual versus combined treatments with interferon alpha, beta and gamma on early infection with HTLV-I in vitro

We have shown previously that infection of mononuclear cells derived from neonatal cord (CBMC) or adult peripheral (PBMC) blood with HTLV-1 can be controlled in vitro by treatment with interferon (IFN) alpha, beta or gamma. The activity of IFNs was mainly related to the induction of an active antiviral competence in host's immune effector cells. The antiviral activity of IFN-boosted CBMC could be ascribed both to a positive regulation of cell-mediated immunity and to inhibition of viral infection. Data described herein provide further information on the mechanisms of the antiviral activity of IFNs and compare the activity of each type of IFN with the association of alpha + beta, alpha + gamma and beta + gamma IFNs, at a concentration of 100 or 1000 IU/ml. When added at the onset of the co-culture of CBMC with lethally irradiated, virus-donor MT-2 cells, IFNs could protect host CBMC by inhibiting HTLV-1 infection in terms of reduced proviral integration and a lower percentage of virus-positive cells, until 4 weeks of culture. Infection of CBMC was inhibited at a comparable extent by either individual or combined IFN treatments. However, a clearcut inhibition of HTLV-I transcription was found only when alpha 100 + beta 1000 IU/ml and especially alpha 1000 + gamma 100 IU/ml combined treatments were tested. When the chronically infected, virus-producing MT-2 cells were treated with IFNs, a remarkable inhibition of HTLV-I transcription was found only after multiple treatments. However, MT-2 cells became resistant to the antiviral activity of IFN gamma, but not to that of IFN alpha or beta. These data provide further information on the control of HTLV-I replication mediated by IFNs at different steps of the viral life cycle, being therefore relevant to the clinical use of combined IFNs in the treatment of acute infection. Moreover, IFNs could be used to prevent the establishment of a persistent infection, which is a prerequisite for developing adult T-cell leukemia (ATL) and/or virus-associated myelopathy.

Comparative anti-viral and anti-proliferative activity of PGA1 and PGJ2 against HTLV-I-infected MT-2 cells

Prostaglandin (PG) A and J exert anti-viral and anti-proliferative effects in a number of experimental models. In particular, multiple treatments with PGAs prevent in vitro the clonal selection of HTLV-I-infected and potentially transformed cord-blood-derived mononuclear cells. Proliferation of HTLV-I-infected leukemic T cells is refractory in most cases to conventional anti-blastic therapy. We examined whether these cyclopentenone PGs might control cell proliferation and/or alter virus replication also in HTLV-I-transformed cells. We show that PGA1 and PGJ2 can exert powerful control of proliferation of the HTLV-I-immortalized, virus-producing MT-2 cell line, in a concentration-dependent fashion. Cells were preferentially arrested at the G1/S interface by treatment with PGA1 or PGJ2 without any detectable cellular toxicity. The anti-proliferative effect of PG treatment was independent of the growth phase of MT-2 cells, since both asynchronous and synchronous cells were sensitive to treatment. This effect was accompanied by an increase in the synthesis of a 70 kDa heat-shock protein (HSP70). However, synthesis of HSP70 was induced to a much greater extent by PGJ2 than by PGA1 at the same concentration. Neither PGA1 or PGJ2 inhibited the transcription of HTLV-I in MT-2 cells, but treatment with PGJ2, and not with PGA1, moderately inhibited the synthesis of viral proteins, i.e., p40 Tax and p19 core proteins. Moreover, infection of recipient K562 cells was significantly inhibited after pre-treatment of MT-2 cells with PGJ2 14 hr before or co-treatment at the onset of the co-culture with K562 cells. This effect was not obtained when MT-2 cells were repeatedly pre-treated with PGJ2 for 1 week before co-culturing. This suggests that reduced infection could be related to impairment of some step in virus-transmission phase.

[Etiopathogenesis and therapeutic trends in adult T-cell leukemia associated with HTLV-I retrovirus]

HTLV-I (Human T-cell leukemia virus type I) has been the first human retrovirus identified and then associated with a definite pathological entity, a leukemic syndrome that specifically affects mature T-lymphocytes (ATL, adult T-cell leukemia), expressing CD3+, CD4+, CD8-, CD11- phenotype. This form of leukemia/lymphoma is endemic in southwestern islands of Japan, although at present the number of HTLV-I seropositive individuals has greatly increased, with a worldwide diffusion, following the expansion wave of the AIDS-associated HIV retrovirus. In fact, double seropositivity for both HIV and HTLV is frequently found among intravenous drug users. Although ATL leukemia or lymphoma occurs with a low frequency among HTLV-I seropositive individuals, it is likely that the evolution from a latent phase of infection to acute leukemia could be favoured by depression of immunosurveillance levels in the host. Therefore, special attention is required to prevent the diffusion of this retrovirus in adults, taking into consideration that newborn babies from seropositive mothers have to be considered at high risk for development of HTLV-I associated disease, on the basis of their immature immunocompetence.

An immunopharmacological approach for prevention of retrovirus-associated disease in human pathology

Retroviruses of the HTLV and HIV subfamilies share a number of similar properties in terms of route of transmission and ultimate targeting to CD4+ T-cells, which results in leukaemic transformation in the case of HTLV and in depletion of CD4+ population and failure of T-helper function in HIV-infected individuals. Both diseases gain poor benefit from therapy at the stage of clinical diagnosis as ATL leukaemia or AIDS, respectively. Therefore the best chances to limit the worldwide distribution of these human retroviruses reside in an effective prevention of viral diffusion, possibly by vaccination, and of the onset of disease in virus-positive subjects. The possibility is discussed of defining protocols to prevent the development of clinical disease. These protocols could be based on pharmacological reconstitution of host's immune reactivity, that is altered early after infection with these retroviruses, and on the control of virus replication by antiviral therapy.

Mononuclear cells from peripheral blood of adult donors and from cord blood are equally protected by alpha- and beta-interferons against infection with HTLV-I

Human mononuclear cells derived from peripheral blood of adult donors (PBMC) or from neonatal cord blood (CBMC) were found to be equally sensitive to the protective effect of alpha- and beta-interferons (IFNs) against the infection with HTLV-I during long-term culture. The effect of IFNs was evidenced by a remarkable reduction of the number of virus-positive cells during culture as evaluated by indirect immunofluorescence for the p19 virus core protein. Moreover, the appearance of p19-positive immortalized clones was inhibited by IFNs in PBMC co-cultures, whereas it was delayed in CBMC cultures. These kinetics are in relation with the higher permissivity of CBMC to the virus in comparison with PBMC, since in CBMC cultures infected cells can be clearly detected starting already 1 week post-infection (p.i.), whereas in PBMC cultures their appearance time is approximately at the 6th week p.i. IFNs acted by 'priming' PBMC and CBMC to an active antiviral competence, since one single treatment with 1000 IU/ml of alpha- or beta-IFN at the onset of the co-culture of mononuclear cells with irradiated virus-donor cells was able to maintain very low levels of infection for approximately 6 weeks in CBMC cultures and at least for 18 weeks in PBMC cultures. As a consequence, it seems likely that IFN action is mediated by the expression of a defined, although not completely identified, set of genes in the host cells.

Selection of HTLV-I positive clones is prevented by prostaglandin A in infected cord blood cultures

Type A prostaglandins (PGA1 and 16,16-dimethyl-PGA2-methyl ester) were found to block the proliferation of HTLV-I infected cord blood lymphocytes (CBL) in vitro, thus preventing the clonal immortalisation that is considered as a predisposing condition to HTLV-I positive leukaemia. PGA1 and di-M-PGA2 did not affect the long-term survival of normal non-infected CBL, whereas they suppressed the proliferation of an established cord-blood derived HTLV-I positive cell line, MT-2. As shown by the number of HTLV-I infected p19+ cells, the block of the selection of immortalised, infected clones by PGAs did not appear to be due to an inhibition of early stages of HTLV-I infection. The possibility that the effect of PGAs could be mediated by an action on the immune response was also examined. PGAs regulated the cell-mediated cytotoxic function of CBL to a different extent when normal non-infected or HTLV-I exposed CBL were compared. In fact, PGAs down-regulated the natural killing and macrophage/lymphocyte cytotoxic response of normal CBL, whereas they did not modify the already depressed immune response of CBL challenged with HTLV-I. These results suggest that the protective effect of PGAs against HTLV-I infection in vitro is mostly related to the direct suppression of the clonal expansion of virus-infected cells, rather than to the anti-viral activity or modulation of the cell-mediated immunity.

Modulation of the cell-mediated immune function by interferon alpha, beta or gamma can partially reverse the immunosuppression induced by human T-cell leukemia virus I in human cord blood cultures

Infection with human T-cell leukemia virus type I (HTLV-I) is associated in vitro and in vivo with a remarkable depression of cell-mediated immune functions. In the present report it is shown that early events following virus-induced suppression of the cell-mediated immune response of freshly isolated cord blood mononuclear cells (CBL) infected with HTLV-I can be partially counteracted by treatment with interferons alpha, beta or gamma (IFN). All three types of IFN exerted a protective effect on CBL cultures exposed to the virus. This resulted in: (a) a reduced number of virus-positive cells until 4 weeks of culture; (b) delay in the clonal expansion of infected cells (IFN alpha and gamma); (c) increased natural killer cell activity of CBL, 1 week post-infection (p.i.), mediated by IFN gamma; (d) increase of allospecific recognition of infecting and priming HTLV-I donor MT-2 cells by CBL in a cytotoxic-T-lymphocyte-like response, mediated by IFN and particularly by IFN gamma; (e) phenotype distribution of CBL subpopulations, tested 4 days p.i., more similar to that of non-infected CBL cultures. In contrast, the overall CBL proliferation, that is profoundly depressed during the first week p.i., was not restored by IFN treatments, suggesting that boosting of the cell-mediated killing induced by IFN might involve the maturation of undifferentiated precursor cells rather than stimulation of their proliferation. The improvement of the efficiency of the antiviral immune response induced by treatment with IFN is likely to contribute to the clearance of virus-positive cells during the early phase of infection. This would provide experimental evidence to support an immunopharmacological approach contributing to the conversion of HTLV-I carriers from positive to negative.

Depression of early phase of HTLV-I infection in vitro mediated by human beta-interferon

Natural human interferon beta (beta-IFN) was tested during the early phase of in vitro infection with HTLV-I virus of human cord blood mononuclear cells (CBL), to evaluate whether its antiviral and immunomodulating effects might prevent spreading of infection in the host. beta-IFN was found to reduce HTLV-I transmission and integration in CBL cultures. Moreover, beta-IFN had no effect in preventing virus transmission and integration in K562 and a very limited effect in HL60 and Molt-4 human tumour lines, suggesting a cell-type specific mode of action. beta-IFN induced a 'priming' response on CBL, since overnight pretreatment of recipient cells or one single treatment at the onset of the coculture were almost equally effective in protecting against HTLV-I infection. During the early days post infection (p.i.), IFN-treated CBL showed a pattern of phenotypic markers that was closer to that of non-infected CBL. In contrast, untreated CBL exposed to HTLV-I showed a percent increase of Tac+, M3+ and Leu 11+ subpopulations. Cell-mediated immune responses of CBL were depressed after coculturing with HTLV-I producer MT-2 cells. beta-IFN was able to boost the cell-mediated cytotoxicity of fresh and infected CBL against both K562 and MT-2 target cells. Leukocyte blastogenesis in mixed lymphocyte/tumour cell cultures, evaluated in terms of 3H-thymidine incorporation during the first week p.i., was also enhanced by IFN when macrophages and lymphocytes were reconstituted at an optimal 1:20 ratio. It is conceivable that this overall enhancement of the immune response induced by beta-IFN could contribute to reduce HTLV-I infection in vitro.

Low concentrations of suramin can reduce in vitro infection of human cord blood lymphocytes with HTLV-I during long-term culture

In vitro infection of human cord blood lymphocytes (CBL) with human T-cell leukemia/lymphoma virus type I (HTLV-I) was found to be reduced by suramin treatment at a concentration ranging from 10-100 micrograms/ml. At higher concentrations (500 micrograms/ml) suramin was toxic to the cells and even resulted in an increased percentage of cells positive for the p19 viral core protein. Suramin treatment at the onset of the CBL coculture with a lethally irradiated HTLV-I donor cell line (MT-2) reduced virus transmission, evaluated as number of p19+ cells, and the consequent amount of integrated provirus in the host genome. The amount of viral RNA transcripts was not reduced in CBL cocultures. On the other hand, suramin affected HTLV-I replication in infected MT-2 cells, when used at a concentration of 50 micrograms/ml, and this might contribute to the reduced infectivity of suramin-treated MT-2 cells. In addition to its antiviral effects, suramin exerted a modest positive regulation on the natural killing activity of CBL and their early proliferative response in mixed lymphocyte/tumor cell culture.

Increased susceptibility of peripheral mononuclear cells of leukemic patients to HTLV-I infection in vitro

Peripheral mononuclear cells (MNC) collected from 12 healthy donors and 44 leukemic patients at various stages of the disease were tested for natural killer (NK) activity and for their susceptibility to HTLV-I infection in vitro, measured in terms of percentage of p19 positive cells. MNC from leukemic donors at any stage of leukemia (ie, onset or relapse, ON/REL; complete remission or off-therapy, CR/OT donors) were highly susceptible to HTLV-I infection. This was true for acute leukemias of lymphoblastic (ALL) or nonlymphoblastic (ANLL) type. MNC of ON/REL patients were more susceptible to HTLV-I than those of CR/OT donors. In addition, leukemic blasts were more rapidly infected (ie, within five to seven days) than the HTLV-I-susceptible normal cord-blood lymphocytes. However, the presence of circulating blasts was not essential to virus susceptibility, since CR/OT MNC, presumably free of leukemic blasts, were still more susceptible to HTLV-I than normal cells. Basal NK function of MNC from leukemic patients was significantly lower than that detectable in healthy controls. However, no correlation was found between susceptibility to HTLV-I infection and NK activity.

Structure and cell-specific expression of a cloned human retinol binding protein gene: the 5′-flanking region contains hepatoma specific transcriptional signals

Human plasma retinol binding protein (RBP) is coded by a single gene and is specifically synthesized in the liver. We have characterized a lambda clone, from a human DNA library, carrying the gene coding for plasma RBP. Southern blot analysis and DNA sequencing show that the gene is composed of six exons and five introns. Primer elongation and S1 mapping experiments allowed the definition of the initiation of transcription and the identification of the putative promoter. The 5'-flanking region of the RBP gene was fused upstream to the coding sequence of the bacterial enzyme chloramphenicol acetyl transferase (CAT): the chimeric gene was introduced, by calcium phosphate precipitation, into the human hepatoma cell line Hep G2 and into HeLa cells. Efficient expression of CAT was obtained only in Hep G2. Primer elongation analysis of the RNA extracted from transfected Hep G2 showed that initiation of transcription of the transfected chimeric gene occurs at a position identical to that of the natural gene. Transcriptional analysis of Bal31 deletions from the 3' end of the RBP 5'-flanking DNA allowed the identification of the RBP gene promoter.

Chemiluminescence of macrophages depends upon their differentiation stage: dissociation between phagocytosis and oxygen radical release

The in vitro differentiation and maturation of resident and activated mouse and human macrophages (M phi) from different anatomical sources was investigated with regard to their oxygen metabolism during zymosan phagocytosis. We found evidence that chemiluminescence (CL) of M phi depends upon their differentiation stage: a) In the absence of any phagocytic stimulus, the human M phi showed a lucigenin-dependent CL background that was approximately 10-fold higher than in mouse M phi and decreased to low levels in resident M phi (monocyte-derived human M phi). This background was reduced by SOD to about 50%. No relevant luminol-dependent background was observed in all mouse and human M phi during culture time. b) Resident and activated mouse and human M phi could be distinguished in terms of their lucigenin-dependent CL during zymosan phagocytosis, which was persistently high in activated M phi, but decreased to comparatively low levels in resident M phi during culture time. This zymosan-elicited CL was almost completely SOD-dependent during all culture time. c) A dissociation between phagocytosis and oxygen radical release is observed: the decrease of both minolul and lucigenin-dependent CL in resident phagocytizing M phi during maturation did not correspond to a decrease of their phagocytic activity. Phagocytosis occurred at a high rate also in the absence of a relevant CL-detectable generation of oxygen radicals. The oxygen radical release, as measured by SOD-inhibitable cytochrome c reduction, paralleled CL during zymosan phagocytosis and declined with maturation of monocytes into M phi. In contrast, the zymosan-induced nitro-blue-tetrazolium reduction increased in mature resident human M phi. Thus, it seems that different metabolic pathways are utilized during phagocytosis in young and mature M phi.

Differential generation of chemiluminescence--detectable oxygen radicals by normal polymorphonuclear leukocytes challenged with sera from systemic lupus erythematosus and rheumatoid arthritis patients

The generation of chemiluminescence (CL)-detectable oxygen radicals by normal human polymorphonuclear leukocytes (PMN) after challenging with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) sera is described. CL was measured in a luminol-dependent assay and referred to a standard obtained when performed immune complexes (Ic) (human tetanus toxoid-antitoxoid Ic resuspended in normal pooled serum) were tested on PMN. Normal sera gave rise to CL activity by PMN between 0% and 50% of the standard Ic (mean +/- standard error of the mean (SEM): 20.7 +/- 4.8). Sera from SLE and RA patients induced strikingly different biological effects on PMN. SLE sera generally induced a high CL-detectable generation of oxygen metabolites which may be causally related to the intense tissue damage (vasculitis) frequently observed in this disease. In contrast to SLE, RA sera induced a CL-detectable respiratory burst by PMN that was included in the normal range. Thus, the biological effects of these sera in terms of stimulation of toxic oxygen radical generation by phagocytes are quite different. This generation of oxygen radicals might reflect a different clearance of circulating Ic by PMN in SLE and RA disease.

Diminished active T rosette levels and increased spontaneous B lymphocyte blastogenesis in hepatitis B virus positive chronic active hepatitis

The present investigation was designed to detect abnormalities in CMI and the presence of polyclonally activated B cells in patients with HBV positive CAH. We studied the peripheral levels and 3H-thymidine incorporation of three lymphocyte subsets: B lymphocytes, as well as two T cell subsets that are either active or late rosetters with high and low affinity receptors respectively for sheep red blood cells (SRBC). In patients the level of peripheral T active cells was decreased, but they exhibited elevated B cell activation. There was also a significant correlation between the decreased levels of T active cells and increased 3H-thymidine incorporation by B lymphocytes. Taken together, our results are consistent with the hypothesis that patients with HBV positive CAH have a severe impairment of T cell function that may lead to an abnormal B cell activation. The increased B cell activity may account for the presence of circulating immune complexes and the variety of autoantibodies often observed in patients with HBV positive CAH.

The influence of bacterial exotoxins and endotoxins on the phagocytic activity of human macrophages in culture

The effect of bacterial exotoxins and endotoxins on phagocytosis was tested on human macrophages in monolayer cultures by determining the rate of zymosan particle ingestion at different toxin concentrations and incubation times. The exotoxins tested were staphylococcal alpha-toxin and diphtheria-toxin. The endotoxins used were lipopolysaccharides from Salmonella typhi, Salmonella typhimurium, Shigella flexneri and Serratia marcescens. Phagocytosis was significantly impaired after prolonged incubation with diphtheria toxin whereas alpha-toxin was ineffective. Endotoxin-treated macrophages showed a wide range of phagocytic activity. Enhancement of phagocytosis was observed with a low concentration of endotoxin (1 microgram/ml) from S. typhi, S. typhimurium and S. flexneri. Higher concentrations (2.5 and 5 micrograms/ml) depressed phagocytosis to varying extents, except for S. typhi lipopolysaccharide, which did not induce a significant decrease in phagocytosis in comparison to the controls.

In-vitro differentiation of human monocytes into mature macrophages during long-term cultures

A method is described which allows human peripheral blood monocytes from any given donor to differentiate in vitro into mature macrophages. About 90% of the starting monocytes are maintained during the long-term culture and are matured to macrophages. Thus cell loss is minimal and the resulting population of mature macrophages can be regarded as representative for all possible macrophage subpopulations present in peripheral blood. These cultures represent a standardized model for in-vitro studies on the role of mature macrophages in various immunological reactions.

Phagocytosis and cellular metabolism (a study on mouse and human macrophages in culture)

The uptake of foreign particles by mouse and human macrophages influenced by various metabolic inhibitors was examined in order to obtain further informations about the energy-dependent mechanisms which are involved in the phagocytic process. The inhibitors employed were iodoacetate, fluoroacetate, fluoride, malonate, sodium azide, 2-4-dinitrophenol, cycloheximide and ouabain. These substances were tested on monolayer cultures and the phagocytosis assay was performed by using zymosan suspension in the nutrient media. The quantitation of phagocytosis was obtained by the direct count of intracellular zymosan particles (immersion microscopy, 100x) and the results were evaluated and compared by biometrical analysis. The effects of these inhibitors on phagocytosis and their relation with the metabolic intracellular pathways are discussed.

Application of health education methods to achieve higher immunization rates

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The influence of some metabolic inhibitors on in vitro phagocytizing macrophages. I. The behaviour of human macrophages

In the present work the uptake of foreign materials by macrophages has been studied in order to elucidate its possible energy-dependent mechanisms. We used monolayer cultures of macrophages from human peripheral venous blood, treated with the following metabolic inhibitors: iodoacetic acid, fluoroacetic acid, sodium fluoride, sodium malonate, sodium azide, 2-4-dinitrophenol, cycloheximide, and ouabain. The test assay was performed by using a zymosan particles suspension in Mc Coy 5 A medium supplemented as follows. The quantitation of phagocytosis was obtained by direct count of intracellular zymosan particles by oil 100X microscopy and the results were submitted to a statistical evaluation. The most effective inhibitor we found was iodoacetate, an inhibitor of anaerobic glycolysis, but fluoride, which acts on the same metabolic pathway at a different site, was quite ineffective. The same ineffectiveness we found for fluoracetate and malonate which act on the Krebs cycle. On the contrary, dinitrophenol (uncoupler of oxidative phosphorylation), azide (inhibitor of cytochrome linked-phosphorylation), ouabain (inhibitor of membrane ATPase activity) and cycloheximide (inhibitor of protein synthesis) give a remarkable decrease of index of phagocytosis after a 3h incubation. In conclusion, we can suppose that the energy-dependent phagocytosis is first depending on transport across the cell membrane (ATPase activity and protein synthesis) and second both on anaerobic glycolysis and oxidative phosphorylation.