Biomedical subjects

M Montroni

Publications and source records attributed to M Montroni.

At least 19 recordsLinked to original sources

PubMed2003

Effects of cryopreservation on lymphocyte immunophenotype and function.

Cryopreservation of isolated peripheral blood mononuclear cells (PBMCs) for phenotypic and functional analyses is considered a standard procedure in order to minimize operator-dependent inter-assay variability and to optimize the use of available resources. However, only few and somewhat conflicting data are presently available on the effects of cryopreservation on PBMCs, especially in samples from HIV-infected patients in which assessment of lymphocyte phenotype and function is of the outmost importance. In this study, we compared fresh versus frozen/thawed (F/T) samples isolated from 19 healthy individuals and 21 HIV-infected patients, showing that cryopreservation induces: (i) a profound decrease of CD62L expression, with a consequent significant decline of the calculated proportions of "naïve" (CD45RA+CD62L+) and "central memory" (CD45RO+CD62L+) T cells; (ii) an increase of the calculated proportions of "effector" CD8+ T cells (CD45RA+CD62L- and CD45RO+CD62L-) in the healthy subjects, while no changes were observed in the HIV-infected group; (iii) a significant decline of CC chemokine receptor 5 (CCR5) expression; (iv) a loss of proliferative responses to some HIV antigens (i.e. p24) and recall antigens [cytomegalovirus (CMV) and Influenza] in HIV-infected patients. We thus conclude that cryopreservation induces a consistent set of changes in PBMCs from both healthy and HIV-infected individuals, and that certain immunological studies of HIV-infected patients (i.e. studies of immune reconstitution following antiretroviral therapy in HIV-infected patients or studies of HIV-infectivity in vitro using CCR5-tropic strains) should be performed on fresh samples.

Cryopreservation↗

PubMed2001

Highly active antiretroviral therapy induces specific changes in effector and central memory T cell sub-populations.

Highly active antiretroviral therapy (HAART) improves the immunodeficiency of HIV-infected individuals. In this report we show that HAART increases both naive (CD45RA+CD62L+) and central memory (CD45RO+CD62L+) CD4 lymphocytes. On CD8 lymphocytes, HAART induces an increase of naive cells associated with a consistent decrease of effector cells (CD45 RO+CD62L-). No specific differences in phenotypic changes were observed with different HAART regimens, suggesting that, once viral suppression is achieved, the pharmacological class of antiretroviral drugs does not affect immune reconstitution.

Antiretroviral Therapy, Highly Active↗

PubMed2001

Abnormal intracellular kinetics of cell-cycle-dependent proteins in lymphocytes from patients infected with human immunodeficiency virus: a novel biologic link between immune activation, accelerated T-cell turnover, and high levels of apoptosis.

Human immunodeficiency virus (HIV)-infection is characterized by loss of CD4+ T cells associated with high levels of immune activation, T-cell proliferation, and lymphocyte apoptosis. To investigate the role of intrinsic perturbations of cell-cycle control in the immunopathogenesis of acquired immunodeficiency syndrome (AIDS), we studied the expression of cell-cycle-dependent proteins in lymphocytes from HIV-infected patients. Cyclin B1 expression, Nucleolar Organizer Regions (NORs) number, and NORs area of distribution were all consistently increased in HIV-infected patients, but returned to normal after effective antiretroviral therapy, suggesting that viral replication is directly implicated in the genesis of the observed changes. Analysis of cyclin B1 intracellular turnover showed that the increased cyclin B1 expression is (1) caused by defective degradation in the presence of normal rates of synthesis, and (2) is temporally associated with decreased levels of ubiquitination. After in vitro activation of lymphocytes from healthy individuals, cyclin B1 and cdc25 expression and ubiquitination, p34 cdc2 activity, NORs morphology, and C23/nucleolin localization showed a 72- to 96-hour cyclic pattern that led to a biologic state similar to baseline. On the contrary, complex but consistent changes of the same indices followed activation of T lymphocytes from HIV-infected patients, resulting in a 5-fold increase in apoptosis. Overall, our data indicate that a profound dysregulation of cell-cycle control is present in lymphocytes from HIV-infected patients. This finding may provide a novel biologic link between immune activation, accelerated lymphocyte turnover, and increased apoptosis during HIV infection.

Anti-HIV Agents↗

PubMed2001

Exogenous interleukin-2 administration corrects the cell cycle perturbation of lymphocytes from human immunodeficiency virus-infected individuals.

Human immunodeficiency virus (HIV)-induced immunodeficiency is characterized by progressive loss of CD4(+) T cells associated with functional abnormalities of the surviving lymphocytes. Increased susceptibility to apoptosis and loss of proper cell cycle control can be observed in lymphocytes from HIV-infected individuals and may contribute to the lymphocyte dysfunction of AIDS patients. To better understand the relation between T-cell activation, apoptosis, and cell cycle perturbation, we studied the effect of exogenous interleukin-2 (IL-2) administration on the intracellular turnover of phase-dependent proteins. Circulating T cells from HIV-infected patients display a marked discrepancy between a metabolic profile typical of G(0) and a pattern of expression of phase-dependent proteins that indicates a more-advanced position within the cell cycle. This discrepancy is enhanced by in vitro activation with ConA and ultimately results in a marked increase of apoptotic events. Conversely, treatment of lymphocytes with IL-2 alone restores the phase-specific pattern of expression of cell cycle-dependent proteins and is associated with low levels of apoptosis. Interestingly, exogenous IL-2 administration normalizes the overall intracellular protein turnover, as measured by protein synthesis, half-life of newly synthesised proteins, and total protein ubiquitination, thus providing a possible explanation for the effect of IL-2 on the intracellular kinetics of cell cycle-dependent proteins. The beneficial effect of IL-2 administration is consistent with the possibility of defective IL-2 function in vivo, which is confirmed by the observation that lymphocytes from HIV-infected patients show abnormal endogenous IL-2 paracrine/autocrine function upon in vitro mitogen stimulation. Overall these results confirm that perturbation of cell cycle control contributes to HIV-related lymphocyte dysfunction and, by showing that IL-2 administration can revert this perturbation, suggest a new mechanism of action of IL-2 therapy in HIV-infected patients.

Antiretroviral Therapy, Highly Active↗

PubMed2001

Sexual behaviour of heterosexual individuals with HIV infection naive for antiretroviral therapy in Italy.

BACKGROUND: Specific information about determinants of sexual behaviour of HIV infected heterosexuals, like injecting drug use (IDU), are essential to design interventions aimed at promoting safer sex practices. METHODS: We analysed data on sexual behaviour collected, between March 1997 and March 1999, through a self administered questionnaire among 1050 IDUs and 642 non-IDU heterosexuals enrolled in a prospective multicentre cohort study on the natural history of HIV infection. RESULTS: Among non-IDU heterosexuals, more women (48.5%) than men (25.1%) (p<0.001) reported that they were infected by HIV positive regular partners whose HIV status they were not aware of. Among the 1119 heterosexual males, one fifth reported having had more than 25 sexual partners during their lifetime. Condom use in the last sexual intercourse was more common among heterosexual IDUs (64.9%) than among non-IDU heterosexual males (58.3%) (p=0.05). Heterosexual IDU males were more likely (66.7%) than non-IDU heterosexuals (50.6%) to have an HIV negative partner (p<0.001). Of the 573 heterosexual females studied, 10.2% reported having had more than 25 lifetime sex partners. This proportion was higher among heterosexual IDUs (18.8%) than among non-IDU heterosexuals (4.3%) (p<0.001). Nearly 50% of the women in both groups reported having used a condom in the last intercourse. Almost 57% of heterosexual IDUs had a current HIV negative partner, compared with 34.9% non-IDU heterosexuals (p<0.001). In both sexes, the findings from univariate analysis were confirmed by multiple logistic regression analysis. CONCLUSIONS: This study identified some important differences, in both males and females, in sexual lifestyles according to injecting drug use (for example, in terms of HIV negative partners). This observation indicates the need to tailor HIV prevention messages according to history of injecting drug use.

Adult↗

PubMed1999

Unscheduled cyclin B expression and p34 cdc2 activation in T lymphocytes from HIV-infected patients.

OBJECTIVE: To study the role of cell cycle regulation during HIV infection by investigating in vivo and in vitro cyclin B and p34 cdc kinase expression. METHODS: Cyclin B expression was analysed by Western blot in CD4 and CD8 cells from 25 HIV-infected patients and 24 uninfected individuals. In eight patients, a sequential analysis was performed after initiation of antiretroviral therapy (ART), and correlations with CD4 cell count and HIV viremia were studied. Sequential changes in cyclin B expression and p34 cdc kinase expression and activity were also studied in lymphocytes activated in vitro with phytohaemagglutinin (PHA). RESULTS: Lymphocytes from untreated HIV-infected patients demonstrate persistent in vivo overexpression of cyclin B in both CD4 and CD8 cell subpopulations. When cells are stimulated to proliferate in vitro, biochemical events that characterize the entrance into the cell cycle [ornithine decarboxylase (ODC) activity, interleukin 2 production, interleukin 2 alpha-chain receptor (IL-2R, CD25) expression, total protein synthesis, total DNA synthesis] show similar timing and sequence in lymphocytes from HIV-infected and uninfected individuals. However, in peripheral blood lymphocytes (PBL) from HIV-infected patients, cyclin B and p34 cdc kinase show premature expression during the cell cycle. Both in vivo cyclin B overexpression and in vitro unscheduled cyclin B expression were almost completely reversed 2-4 weeks after initiation of effective ART. CONCLUSION: Increased and unscheduled expression of cyclin B and p34 cdc kinase is consistently observed in CD4 and CD8 cells from HIV-infected patients, both in vivo and after in vitro mitogenic stimulation. These alterations correlate with the level of viremia and may provide a link between the perturbation of lymphocyte proliferative homeostasis and the exaggerated propensity towards apoptosis.

Apoptosis↗

PubMed1999

Host-specific modulation of the selective constraints driving human immunodeficiency virus type 1 env gene evolution.

To address the evolution of human immunodeficiency virus type 1 (HIV-1) within a single host, we analyzed the HIV-1 C2-V5 env regions of both cell-free genomic-RNA- and proviral-DNA-derived clones. Sequential samples were collected over a period of 3 years from six untreated subjects (three typical progressors [TPs] and three slow progressors [SPs], all with a comparable length of infection except one. The evolutionary analysis of the C2-V5 env sequences performed on 506 molecular clones (253 RNA- and 253 DNA-derived sequences) highlighted a series of differences between TPs and SPs. In particular, (i) clonal sequences from SPs (DNA and RNA) showed lower nucleotide similarity than those from TPs (P = 0. 0001), (ii) DNA clones from SPs showed higher intra- and intersample nucleotide divergence than those from TPs (P < 0.05), (iii) higher host-selective pressure was generally detectable in SPs (DNA and RNA sequences), and (iv) the increase in the genetic distance of DNA and RNA sequences over time was paralleled by an increase in both synonymous (Ks) and nonsynonymous (Ka) substitutions in TPs but only in nonsynonymous substitutions in SPs. Several individual peculiarities of the HIV-1 evolutionary dynamics emerged when the V3, V4, and V5 env regions of both TPs and SPs were evaluated separately. These peculiarities, probably reflecting host-specific features of selective constraints and their continuous modulation, are documented by the dynamics of Ka/Ks ratios of hypervariable env domains.

Base Sequence↗

PubMed1998

Early increase of CD4+ CD45RA+ and CD4+ CD95- cells with conserved repertoire induced by anti-retroviral therapy in HIV-infected patients.

Administration of anti-retroviral drugs induces a decrease of viral load associated with increase of CD4+ cell count in most HIV-infected patients. To investigate the early changes in CD4+ cell phenotype induced by anti-retroviral therapy, six patients with CD4+ cell count > 100/mm3 and never treated with anti-HIV therapy were enrolled and blood samples collected several times within 14 days from the initiation of therapy with Zidovudine plus Didanosine. CD4+ cell count and HIV viraemia were investigated at each time point, as well as the expression of CD45RA, CD45RO and CD95/Fas molecules on CD4+ cells, and the T cell receptor (TCR) Vbeta repertoire of CD4+ cells. All patients showed a rapid and dramatic decrease in viral load with a corresponding increase of CD4+ cell count. The main remodelling of CD4+ cell subpopulations took place in the first 14 days of therapy, and consisted of: (i) increased CD4+CD45RA+/CD4+CD45RO+ ratio; (ii) decrease of CD95/Fas expression. The rise in absolute number of CD4+CD45RA+ cells was paralleled by an increase of CD4+CD95/Fas- cells and accounted for most of the early increment of CD4+ cell count. The TCR Vbeta repertoire of CD4+ cells was conserved after anti-HIV therapy, with the exception of two patients with expanded CD4+Vbeta12+ cells, which also tested CD45RA+ and CD95/Fas-. These experiments show that newcomer CD4+ lymphocytes are CD45RA+CD95/Fas- cells, suggesting that blocking HIV replication causes an early and antigen-independent proliferation of possibly 'naive' cells unprimed for CD95/Fas-mediated apoptosis. These cells expressed a conserved and widespread TCR repertoire, suggesting that their capability for antigenic recognition is intact.

Adult↗

PubMed1997

Oxidative protein damage and degradation in lymphocytes from patients infected with human immunodeficiency virus.

It has been proposed that oxidative stress is the common mediator of apoptotic cell death in AIDS. However, mechanistic relationships between oxidative damage and cell death are far from clear. It is reported here that the mitogenic activation of T lymphocytes from human immunodeficiency virus-positive subjects involves perturbation of redox balance, as indicated by the increase in hydroethydine intracellular oxidation and manganese superoxide dismutase adaptive induction. Principal molecular targets of oxidative injury are cellular proteins whose content in carbonyl groups increases together with a dramatic increase in degradation of newly synthesized proteins catalyzed by the ATP- and ubiquitin-dependent proteolytic system. The major consequence of this metabolic anomaly is the decrease in protein cell mass leading to cells that are smaller than normal at lethal mitosis.

Adult↗

PubMed1997

Dynamic features of human immunodeficiency virus type 1 (HIV-1) viremia: kinetics of cell-free HIV-1 RNA after therapeutic plasma exchange.

To gain insight into the variables that influence the dynamics of human immunodeficiency virus type 1 (HIV-1) viremia levels, HIV-1 RNA molecules were quantified in plasma from an infected patient undergoing therapeutic plasma exchange (TPEx). After each TPEx procedure (2000 mL of fluid exchanged per session), HIV-1 genome molecule levels dropped to 58%-63% of the basal level but rapidly reverted to pre-TPEx values (doubling time = 3.50-4.04 h). Of interest, mobilization of extravascular cell-free virions (on average, 5.15 x 10(4) viral genome molecules/h) had already occurred during TPEx. After three daily TPEx procedures, HIV-1 viremia rebounded to basal values, while HIV-1 proviruses and viral transcripts in peripheral blood lymphocytes constantly tested at stable levels. Overall, this study extends previous analyses of the rate of HIV-1 turnover, using an alternative approach to the use of antiretroviral drugs, and it provides, albeit indirectly, insights into the amount and dynamic features of extravascular cell-free virus.

Cell-Free System↗

PubMed1997

Changes in CD8 cell subpopulations induced by antiretroviral therapy in human immunodeficiency virus infected patients.

Although CD4+ T cells are the main target of HIV infection, CD8+ cells also play important roles in the interaction between HIV and the host immune system. The aim of this study was to analyze the effect of anti-HIV therapy on the relative proportion of some important CD8+ cell subpopulations. Five HIV-infected patients were enrolled, and blood samples were collected several times, within 90 days from the initiation of therapy. CD4+ cell count and HIV viremia were investigated, as well as the expression of CD38, HLA-DR, CD28, CD57, CD30, CD95 molecules on CD8+ cells. A complex remodeling of CD8+ cell subpopulations took place between week 2 and week 7 of treatment. This remodeling mainly consisted of: i) decrease of CD8+CD38+ and CD8+DR+ cells; ii) increase of CD8+CD28+ cells; and iii) decreased expression of the CD95/Fas molecule on CD8+ cells. Overall, these findings suggest that effective anti-HIV therapy induces changes of CD8+ subpopulations showing the reversal of the state of chronic activation that is caused by viral replication.

Adult↗

PubMed1996

c-myb proto-oncogene is expressed by quiescent scleroderma fibroblasts and, unlike B-myb gene, does not correlate with proliferation.

Systemic sclerosis (scleroderma) is characterized by excessive deposition of extracellular matrix constituents. Although it has been proposed that tissue fibrosis is due to increased fibroblast synthesis of various collagen polypeptides, there is some experimental evidence that patients with systemic sclerosis have a defect in the control of fibroblast growth. The myb family of genes includes, among others, the c-myb proto-oncogene and the structurally related gene, B-myb, which are both implicated in the regulation of differentiation and/or proliferation of hematopoietic and nonhematopoietic cells. To elucidate the molecular basis responsible for scleroderma fibroblast proliferation, we therefore elected to investigate the expression of c-myb and B-myb genes in scleroderma and control cells. Using the reverse transcriptase polymerase chain reaction technique, we detected c-myb transcripts in scleroderma skin fibroblasts rendered quiescent by serum deprivation. Under the same experimental conditions, c-myb message was not found in normal skin fibroblasts, but, after serum stimulation, c-myb RNA was clearly evident from 3 to 72 h in both normal and pathologic cells. Treatment of these cells with c-myb antisense oligonucleotides caused downregulation of c-myb expression, and the inhibition of scleroderma fibroblast proliferation was 42%, whereas in normal fibroblasts the inhibition was weaker (22%). In contrast to c-myb, in normal and scleroderma fibroblasts the level of expression of B-myb correlated with cell proliferation assessed by cell count, and densitometric analysis showed that B-myb message was 1.5-5 times higher in most of pathologic cells studied. The antisense B-myb oligonucleotides had a weaker antiproliferative effect compared with antisense c-myb, inhibiting scleroderma and normal fibroblasts by 23% and 13%, respectively. These data suggest that the B-myb and c-myb genes may play a role in scleroderma fibroblast proliferation and function.

Aged↗

PubMed1996

Dynamics and modulation of human immunodeficiency virus type 1 transcripts in vitro and in vivo.

The dynamics of human immunodeficiency virus type 1 (HIV-1) transcription was analyzed in vitro and in vivo by using a specific molecular approach which allows accurate quantitation of the different classes of viral mRNAs. Unspliced (US) and multiply spliced (MS) HIV-1 transcripts were assayed by competitive reverse transcription (cRT)-PCR, using a single competitor RNA bearing in tandem internally deleted sequences of both template species. Acute HIV-1 infection of primary peripheral blood mononuclear cells (PBMCs), monocytes/macrophages cells, and the A3.01 T-lymphocyte-derived cell line was studied; both classes of HIV-1 mRNAs increased exponentially (r2 > 0.98) at days 1 to 3 and 1 to 4 postinfection in HIV(IIIB)-infected A3.01 cells and PBMCs, respectively, whereas monocytes/macrophages infected with monocytotropic HIV(BaL) exhibited a linear (r2 = 0.81 to 0.94) accumulation of US and MS transcripts. Following induction of chronically infected ACH-2 cells, MS transcripts increased 2 h postinduction and peaked at 5 h (doubling time, 58 min), while at 24 h, US mRNAs increased 3,053-fold compared with basal time (doubling time, 137 min). To address the biopathological significance of HIV-1 expression pattern during infection progression, pilot cross-sectional and longitudinal analyses were carried out with samples from untreated and treated HIV-1-infected patients. In almost all untreated (recently infected, long-term nonprogressor, and progressor) patients, MS transcript levels followed the general trend of systemic HIV-1 activity. In patients under treatment with powerful antiretroviral compounds, viral MS transcripts rapidly fell to undetectable levels, indicating that in vivo, levels of MS mRNAs in PBMCs are closely associated with the number of newly infected cells and suggesting a new role for the quantitative analysis of HIV-1 transcription in infected patients.

Cell Line↗

PubMed1996

[Prognostic factors in acute nonlymphoid leukemias].

Our retrospective study was aimed at assessing parameters affecting the prognosis of acute non lymphoid leukemia (ANLL). Since 1988 to 1994 we observed 84 patients: 52 males, 32 females. For each patient we considered at diagnosis: age, fever, performance status, platelets, hemoglobin and white blood cell count, extramidollary disease, bone marrow blastosis, phenotype and cytogenetic abnormalities of blasts cells. All the parameters listed above were correlated with the time to achieve the complete remission (CR), CR duration and the overall survival. Statistical tests as t-student and chi square test were used. Statistical analysis of the parameters considered revealed that the only value affecting the achievement of a CR was the age. The prognostic significance of immunophenotyping in ANLL has been a controversial issue, with a number of conflicting reports. In our study only the terminal deoxynucleotidyl transferase was significantly associated with prognosis. Our study, as data reported in literature, confirms that the prognostic impact of the various parameters in ANLL is controversial. The study of prognostic factors and of the immunophenotype is important to identify the clinical and the biologic profile of the disease and to evaluate the optimal post-remission treatment.

Adult↗

PubMed1996

[Neuro-SLE. Models of its clinical expression].

In this paper we considered different models concerning the clinical expression of neuropsychiatric involvement in course of systemic lupus erythematosus (SLE). These models describe pathological conditions as multifocal cerebropathy, transverse myelitis, peripheral neuropathy and panic attacks. We have chosen these cases as clinical example of different pathogenic mechanisms responsible of CNS-lupus, as hypercoagulation due to antiphospholipid syndrome, immune-complex vasculitis, complement-mediated autoantibody damage and antibody-induced cytotoxicity. The prevalence of neuropsychiatric manifestations in 122 SLE patients is also reported. Finally, the paper reports some guidelines about diagnostic and therapeutic behaviour in course of CNS-lupus.

Adolescent↗

PubMed1995

Cervical dysplasia in HIV-seropositive women: role of human papillomavirus infection and immune status.

OBJECTIVE: In the present study we investigated the cytologic and colposcopic characteristics of a cohort of HIV-infected women, with the aim to determine a relationship between immunologic status and frequency and/or severity of cervical abnormalities. MATERIALS AND METHODS: 21 women, who tested positive for the HIV antibody and who were admitted as outpatients because of various gynecologic complications or because of an HIV infection that was under regular clinical surveillance. A pelvic examination was performed and Papanicolaou smears were obtained from endocervix and ectocervix before colposcopic examination. Cytologic samples for human papillomavirus (HPV) detection by polymerase chain reaction were also collected. Results obtained in the group of HIV-infected women were compared with findings in a group of 473 seronegative women recruited consecutively from our outpatient population. Serum samples for T lymphocytes were drawn within 2 weeks of cytologic and colposcopic examination. CD4 and CD8 monoclonal antibodies were purchased from Becton Dickinson (Mountain View, Calif., USA). RESULTS: HIV-infected women had a significantly higher percentage of HPV DNA positivity with respect to the outpatient population (67 vs. 7%, respectively, p < 0.001). Analysis of cytologic specimens revealed 9 women (43%) with cytologic evidence of cervical dysplasia in the HIV-seropositive group vs. 23 (5%) of 473 in the outpatient population (p < 0.001). All the HIV-seropositive women with cervical dysplasia presented an associated HPV DNA positivity; in particular, the percentage of associated HPV DNA type 16 in cervical dysplasia was 78% (7/9 cases). In HIV-infected women, the evaluation of T lymphocyte subset distribution suggested a significant relationship between CD4+ cell decrease and severity of cytologic findings (p = 0.03). DISCUSSION: The HIV-infected women had a tenfold higher prevalence of both HPV infection and cervical dysplasia than the outpatient population; this increased risk seems to be limited mainly to those who also had genital HPV infection. The analysis of immunologic status confirmed previous observations that an impaired immune system results in increased cervical disease.

Adult↗

PubMed1995

Addition of erythropoietin to granulocyte colony-stimulating factor after priming chemotherapy enhances hemopoietic progenitor mobilization.

Hemopoietic progenitor cell mobilization intended for autotransplantation is now feasible in many patients, following the administration of single cytokines (G-CSF, GM-CSF, IL-3) or their combination. Erythropoietin (EPO) is a cytokine which showed an interesting activity also on non-erythroid progenitors, however the clinical relevance of this activity has not been sufficiently investigated yet. This retrospective study has attempted to assess the effectiveness of the combination of EPO plus G-CSF after priming chemotherapy to increase the number of blood progenitor cells, as compared to the results obtained by G-CSF alone. Thirty-four patients underwent priming chemotherapy followed by cytokine administration: 18 patients received G-CSF 5 micrograms/kg/day and 16 patients G-CSF plus EPO 50 U/kg/day. The two groups were homogeneous as regards the main clinical characteristics which are thought to affect BPC mobilization. As for hemopoietic progenitor cell mobilization, we observed that the combination of EPO and G-CSF was more effective in comparison with G-CSF alone, with a median of 1.9-fold for circulating MNC, 4.0-fold for CFU-GM, 4.7-fold for BFU-E and 2.8-fold increase for CD34+ cells. The results of apheresis collections revealed that the same group of patients showed better results for total blood progenitor cells/kg. The difference was statistically significant both for BPC mobilization and collection. Our findings suggest that EPO has a synergistic activity with G-CSF in mobilizing hemopoietic progenitors; the good results obtained, despite our pretreated patients, suggest that this cytokine combination has both biologic and clinical relevance.

Adolescent↗

PubMed1994

Intercellular adhesion molecules (ICAM)-1 ICAM-2 and ICAM-3 function as counter-receptors for lymphocyte function-associated molecule 1 in human immunodeficiency virus-mediated syncytia formation.

It has been previously demonstrated that lymphocyte function-associated molecule 1 (LFA-1) plays a major role in human immunodeficiency virus (HIV)-mediated syncytia formation. In the present study we investigated the involvement of intercellular adhesion molecule-1 (ICAM-1), ICAM-2 and ICAM-3 in the process. The ability of monoclonal antibodies (mAb) directed against ICAM-1, ICAM-2 and ICAM-3 to block syncytia was analyzed either in phytohemagglutinin (PHA)-activated lymphocytes infected in vitro with primary or laboratory strains of HIV or by coculturing a T cell line stably expressing HIV envelope with PHA-activated lymphocytes. Complete inhibition of syncytia formation was observed only by the simultaneous addition to the cell cultures of all (i.e. anti-ICAM-1, anti-ICAM-2 and anti-ICAM-3) mAb. These results indicate that the interaction between LFA-1 and ICAM is a critical step in HIV-mediated syncytia formation, and that ICAM-1, ICAM-2 and ICAM-3 are the receptor molecules for the LFA-1-dependent syncytia formation.

Antibodies, Monoclonal↗