Fatty acid binding protein 5 inhibition attenuates pronociceptive cytokine/chemokine expression and suppresses osteoarthritis pain: A comparative human and rat study

OBJECTIVE

Osteoarthritis (OA) is often accompanied by debilitating pain that is refractory to available analgesics due in part to the complexity of signaling molecules that drive OA pain and our inability to target these in parallel. Fatty acid binding protein 5 (FABP5) is a lipid chaperone that regulates inflammatory pain; however, its contribution to OA pain has not been characterized.

DESIGN

This combined clinical and pre-clinical study utilized synovial tissues obtained from subjects with end-stage OA and rats with monoiodoacetate-induced OA. Cytokine and chemokine release from human synovia incubated with a selective FABP5 inhibitor was profiled with cytokine arrays and ELISA. Immunohistochemical analyses were conducted for FABP5 in human and rat synovium. The efficacy of FABP5 inhibitors on pain was assessed in OA rats using incapacitance as an outcome. RNA-seq was then performed to characterize the transcriptomic landscape of synovial gene expression in OA rats treated with FABP5 inhibitor or vehicle.

RESULTS

FABP5 was expressed in human synovium and FABP5 inhibition reduced the secretion of pronociceptive cytokines (interleukin-6 [IL6], IL8) and chemokines (CCL2, CXCL1). In rats, FABP5 was upregulated in the OA synovium and its inhibition alleviated incapacitance. The transcriptome of the rat OA synovium exhibited >6000 differentially expressed genes, including the upregulation of numerous pronociceptive cytokines and chemokines. FABP5 inhibition blunted the upregulation of the majority of these pronociceptive mediators.

CONCLUSIONS

FABP5 is expressed in the OA synovium and its inhibition suppresses pronociceptive signaling and pain, indicating that FABP5 inhibitors may constitute a novel class of analgesics to treat OA.

Urticaria and coronavirus infection: a lesson from SARS-CoV-2 pandemic

Summary

Urticaria is a condition involving both skin and mucosal tissues characterized by the presence of wheals and/or angioedema. The acute form has been related to allergic reactions to drugs or foods, interaction with chemicals, or infections. We reviewed the association of urticaria with coronavirus infections. This review was carried out by the use of two search engines for published original articles, employing two key terms correlated to urticaria and viruses: "urticaria" and one term linked to each virus. The research of the relationships between SARS-CoV-2 and urticaria produced 18 papers (including a total of 114 cases). Surprisingly, the search for cases of urticaria in patients with SARS-CoV or MERS produced no results. We tried to interpret this discrepancy and attempted to analyze the possible pathogenesis of urticaria lesions in SARS-CoV-2.

Effects of non-invasive ventilation on renal and endothelial function in patients with respiratory failure

OBJECTIVE

Non-invasive positive pressure ventilation (NIV) is now an indispensable safeguard in the management of many pathologies. However, sometimes the positive end-expiratory pressure (PEEP) showed harmful effects on renal function, although effects on renal hemodynamic are unclear. We aimed at evaluating the effects of NIV on renal and endothelial function, in patients with chronic or acute respiratory failure.

PATIENTS AND METHODS

We performed a longitudinal, prospective, interventional study. We enrolled 17 hospitalized and non-hospitalized patients (11 males) with indication to NIV and stable hemodynamic parameters. Patients were treated with NIV and followed up at T0, at T1 (at the end of the NIV cycle) and at T2 (fifteen days after).

RESULTS

17 patients (11 males) with a mean age of 71.94 ± 14.89 years were enrolled. A significant increase in flow mediated dilation (FMD) was found (p = 0.004). We showed a significant improvement, after NIV, in the values of pH (p = 0.0002), pCO2 (p = 0.0001), pO2 (p = 0.04), lactates (p = 0.04), sO2 (p = 0.02) and in the P/F Ratio (p = 0.004). We also showed a significant reduction of serum glucose (p = 0.01) and a significant increase of serum chlorine (p = 0.047), while we did not report a significant increase of creatinine (p = 0.297) or a significant change in diuresis.

CONCLUSIONS

In our study NIV has no significant effects on renal function in patients with respiratory failure. Probably these patients required low PEEP values, which were less harmful to lung parenchyma and not effective on systemic hemodynamic. Furthermore, NIV has improved endothelial function in the short term, likely by reducing oxidative stress, as improvements of the gas-analysis parameters showed. Therefore, NIV could help to reduce cardiovascular risk of patients improving endothelial function.

Monolithic zirconia and digital impression: case report

AIMS

The aim of this study is to present a clinical case of a full arch prosthetic rehabilitation on natural teeth, combining both digital work-flow and monolithic zirconia.

PATIENTS AND METHODS

Digital impression was taken with an intraoral optical scanner (CS3500, Carestream Dental, Atlanta, GA, USA). A prosthetic rehabilitation was realized on natural teeth using monolithic zirconia from 1.6 to 1.4 and from 2.7 to 2.4 frameworks, while in the aesthetic area (from 2.3 to 1.3), technicians left on the structure a 0.8 mm vestibular space for ceramic layering.

DISCUSSION

The combination of digital impression technology and the use of the monolithic zirconia had demonstrated the delivery of the final prosthetic device in a quick time without the need to remodel functional or aesthetic areas. The digital work-flow combines intraoral optical impression techniques and CAD/CAM technology, in order to achieve a fully digital and successful way to deliver prosthetic restorations to patients, providing aesthetics and function in shorter intervals of time. The clinical outcome of this study was satisfactory but a long-term evaluation is needed.

Impaired Natural Killer Cell Activity Associates with Increased Susceptibility to Inflammation Induced by Herpesvirus Infection in Patients with Nickel Hypersensitivity

Nickel (Ni) is one of the most common causes of allergic contact dermatitis (ACD) and the number one allergen in the frequency of positive patch test reactions. The cellular basis of ACD is the lack of specialized T cells with regulatory function allowing for the expansion of Ni[Formula: see text] specific cytotoxic CD8+ T cells. However, Ni also exerts a number of not yet fully understood activities on cells belonging to the immune system. To this regard, an immunosuppressive activity of Ni on natural killer (NK) cells has been repeatedly suggested both in animal models and humans. Here we demonstrate that NK activity of Ni[Formula: see text] intolerant patients was significantly lower than observed in controls. Moreover, the addition of Ni[Formula: see text] sulphate to cultures of peripheral blood lymphocytes (PBL) obtained by Ni[Formula: see text] allergic patients, further depressed the NK cell activity. Finally, according to the key role exerted by NK cells in containing viral infections, we found an increased frequency of Herpesvirus 1 (HSV-1) recurrence among patients with Ni[Formula: see text] allergy. In conclusion, our results indicate that Ni[Formula: see text] allergic patients may present reduced NK cell response, this resulting in turn in increased susceptibility to viral infections. Patch testing should be considered in individuals affected by unexplained recurrences of HSV-1 infection.

The influence of cement filler load on the radiopacity of various fibre posts ex vivo

AIM

To verify whether the filler load of luting agents influences the radiopacity of intraradicularly placed posts.

METHODOLOGY

Digital radiographs of the following posts were taken: RelyX Fiber Post (3M ESPE), GC Fiber Post (GC Corporation), DT Light Post Illusion (RTD), DT Light SL Post (RTD), Endo-Composipost (RTD), FibreKleer Parallel Post (Jeneric Pentron Incorporated), FRC Postec (Ivoclar Vivadent), Parapost Taper Lux (Còltene/Whaledent AG), Radix Fiber Post (Dentsply Maillefer), EverStick Post (Stick Tech Ltd), Dentin Post X (Komet), Tech 21 X-op (Isasan), ENA Post (Micerium). Post radiopacity was measured in millimetres of aluminium (mmAl) with reference to an aluminium step wedge. Two extracted contralateral premolars were root filled. After post space preparation, taking the midpoint of the post hole as a reference, each tooth was cut longitudinally into two halves in a mesiodistal direction. On each half, the exposed root dentine was ground flat to the deepest point of the post space, and an even layer of cement was placed and light-cured. To obtain a clinically relevant layer of cement, the material thickness was reduced to 75 μm by grinding with wet abrasive paper. A cement formulation with 30 wt% of filler was tested in one premolar, whilst a formulation with 70 wt% of filler was utilized in the contralateral tooth. Posts were then placed between the two facing root halves of each premolar, and radiopacity was measured in mmAl. Data were analysed using t-test for paired samples (P < 0.05).

RESULTS

Radiopacity of posts ranged between 1.44 (ENA Post) and 5.78 mmAl (FibreKleer). In the presence of the more heavily filled cement, significantly higher values of post radiopacity were measured (P < 0.001).

CONCLUSION

The radiopacity of the luting agent contributed to the overall post radiovisibility within the root. Even when the cement with lower filler content was used in combination with the least radiodense dowels, the post was detectable within the root.

Skewed T-cell receptor variable β repertoire and massive T-cell activation in idiopathic orofacial granulomatosis

Orofacial granulomatosis (OFG) is a clinicopathologic entity describing oral lesions with noncaseating granulomas including a spectrum of diseases such as the Melkersson-Rosenthal syndrome. The involvement of abnormal T-cell responses has been suggested in the pathogenesis of OFG although few and contrasting data are currently available on this issue. In a patient with OFG, we observed virtually complete CD4 and CD8 T-cell receptor (TCR) β-chain variable region (BV) repertoires at the lesion level and in circulation. However, oligoclonal profiles were found in CD4 and, to a greater extent, in CD8 subsets. These findings were seen in association with a massive peripheral T-cell activation, decreased naive T cells, reduced thymic output, altered cytokine production, and increased apoptosis. Our data, pointing to a random influx of T cells at the site of inflammation, argue against the hypothesis of a main allergen acting at the level of oral mucosa. The profound dysregulation of the peripheral T-cell compartment suggests that OFG should be regarded as a systemic disorder with localized manifestations.

Long-Term N-Acetylcysteine Therapy in Systemic Sclerosis Interstitial Lung Disease: A Retrospective Study

Systemic sclerosis (SSc) is associated with interstitial lung diseases. The primary endpoints of this study were changes between baseline and month 24 in single-breath carbon monoxide diffusing capacity (DLco). The secondary endpoints were: vital capacity (VC), forced expired volume in 1 sec (FEV1), total lung capacity (TLC), scores of high resolution computed tomography (HRCT) of the chest, number of adverse effects. In this study, we retrospectively investigated data from SSc patients who had undergone therapy with high-dose intravenous N-acetylcysteine (NAC) at a dosage of 15 mg/Kg/h for 5 consecutive hours every 14 days. After NAC therapy median values of DLco (69.5% vs 77.7%), VC (99% vs 101.3%) and TLC (93% vs 98.3%) significantly increased. We did not observed any significant changes from baseline in FEV1 value and HRTC score. The improvement in lung function was more evident in SSc patients without radiological signs of pulmonary fibrosis than in patients with pulmonary fibrosis. In SSc patients with mild-moderate pulmonary fibrosis intravenous NAC administration slows the rate of deterioration of DLco, VC and TLC. In conclusion, this retrospective study demonstrates that long-term therapy with intravenous NAC ameliorates pulmonary function tests in SSc patients.

Recurrent infections in patients with nickel allergic hypersensitivity

Nickel (Ni) is the most common contact allergen among the general population in the industrialized world. Ni has been shown to exhibit immunomodulatory, if not immunotoxic, effects in several experiments conducted on humans and on rodents. This study tests the incidence of different infectious diseases in 100 patients with Ni hypersensitivity and compares it to data from 100 healthy volunteers. One hundred subjects with Ni hypersensitivity were enrolled. A group of 100 matched healthy volunteers with negative European standard patch test were enrolled as healthy controls. In patients with Ni hypersensitivity a higher incidence of recurrent herpes labialis (RHL), urinary tract infections (RUTI), genital candidiasis, and upper respiratory tract infections (RURTI) was detected. Fifteen patients with nickel allergic hypersensitivity (NAH) followed a Ni-poor diet. After a one-year diet a net reduction of incidence of RHL was found. Indeed, the number of episodes of RHL per year decreased from 6 +/- 2.75 to 2.4 +/- 1.2. Conversely, among the matched control group with NAH following a normal daily dietary nickel intake the RHL number did not show any statistically significant changes (6.1 +/- 1.7 vs 6 +/- 1.5 ). In conclusion, our study demonstrates a higher incidence of recurrent infections among patients with NAH. A low-Ni diet reduces the number of RHL episodes per year.

Constitutively active PTH/PTHrP receptor in odontoblasts alters odontoblast and ameloblast function and maturation

Parathyroid hormone (PTH)-related protein (PTH-rP) is an important autocrine/paracrine attenuator of programmed cell differentiation whose expression is restricted to the epithelial layer in tooth development. The PTH/PTHrP receptor (PPR) mRNA in contrast is detected in the dental papilla, suggesting that PTHrP and the PPR may modulate epithelial-mesenchymal interactions. To explore the possible interactions, we studied the previously described transgenic mice in which a constitutively active PPR is targeted to osteoblastic cells. These transgenic mice have a vivid postnatal bone and tooth phenotype, with normal tooth eruption but abnormal, widened crowns. Transgene mRNA expression was first detected at birth in the dental papilla and, at 1 week postnatally, in odontoblasts. There was no transgene expression in ameloblasts or in other epithelial structures. Prenatally, transgenic molars and incisors revealed no remarkable change. By the age of 1 week, the dental papilla was widened, with disorganization of the odontoblastic layer and decreased dentin matrix. In addition, the number of cusps was abnormally increased, the ameloblastic layer disorganized, and enamel matrix decreased. Odontoblastic and, surprisingly, ameloblastic cytodifferentiation was impaired, as shown by in situ hybridization and electron microscopy. Interestingly, ameloblastic expression of Sonic Hedgehog, a major determinant of ameloblastic cytodifferentiation, was dramatically altered in the transgenic molars. These data suggest that odontoblastic activation of the PPR may play an important role in terminal odontoblastic and, indirectly, ameloblastic cytodifferentiation, and describe a useful model to study how this novel action of the PPR may modulate mesenchymal/epithelial interactions at later stages of tooth morphogenesis and development.

Biased T-cell receptor repertoires in patients with chromosome 22q11.2 deletion syndrome (DiGeorge syndrome/velocardiofacial syndrome)

Chromosome 22q11.2 deletion (del22q11.2) syndrome (DiGeorge syndrome/velocardiofacial syndrome) is a common syndrome typically consisting of congenital heart disease, hypoparathyroidism, developmental delay and immunodeficiency. Although a broad range of immunologic defects have been described in these patients, limited information is currently available on the diversity of the T-cell receptor (TCR) variable beta (BV) chain repertoire. The TCRBV repertoires of nine patients with del22q11.2 syndrome were determined by flow cytometry, fragment size analysis of the third complementarity determining region (CDR3 spectratyping) and sequencing of V(D)J regions. The rate of thymic output and the phenotype and function of peripheral T cells were also studied. Expanded TCRBV families were detected by flow cytometry in both CD4+ and CD8+ T cells. A decreased diversity of TCR repertoires was also demonstrated by CDR3 spectratyping, showing altered CDR3 profiles in the majority of TCRBV families investigated. The oligoclonal nature of abnormal peaks detected by CDR3 spectratyping was confirmed by the sequence analysis of the V(D)J regions. Thymic output, evaluated by measuring TCR rearrangement excision circles (TRECs), was significantly decreased in comparison with age-matched controls. Finally, a significant up-regulation in the percentage, but not in the absolute count, of activated CD4+ T cells (CD95+, CCR5+, HLA-DR+), IFN-gamma - and IL-2-expressing T cells was detected. These findings suggest that the diversity of CD4 and CD8 TCRBV repertoires is decreased in patients with del22q11.2 syndrome, possibly as a result of either impaired thymic function and/or increased T-cell activation.

T-Cell immune activation in children with vertically transmitted hepatitis C virus infection

Little is known concerning the clinical features, the histological outcome, and the effects on the maturation of immune system of children with vertically-transmitted hepatitis C virus (HCV) infection. Specifically, no data are available on the peripheral distribution of T-cell subsets. The frequency of naive and memory cells, activated T cells, and cytokine-producing T cells was analyzed in nine HCV-infected children born to HCV-positive mothers. In HCV-infected children, the distribution of naive and memory cells was not significantly altered in the CD4 subset whereas within the CD8 subset, an increase of memory and a decrease of naive cells was observed. The frequency of HLA-DR-positive and Fas-positive T cells was increased in HCV-infected children in both CD4 and CD8 subsets. The distribution of Fas-expressing T cells was directly related to that of HLA-DR cells and inversely related to the frequency of naive T cells. In regard with cytokine production we found increased levels of both CD4 and CD8 interferon-gamma (IFN-gamma)-producing cells whereas no difference in the percentage of interleukin-2 (IL-2)-producing T cells was observed. No meaningful correlation was observed between individual T cell subsets and ALT levels or HCV viral load. In conclusion, our results indicate an increased T-cell activation and a shift to a T(H)1 pattern of cytokine production in children with vertically transmitted HCV infection. The cause of this kind of immune response could reside in the persistent antigenic stimulation by chronic HCV infection.

T cell responses to highly active antiretroviral therapy defined by chemokine receptors expression, cytokine production, T cell receptor repertoire and anti-HIV T-lymphocyte activity

The immunological correlates of highly active antiretroviral therapy (HAART)-induced suppression of human immunodeficiency virus type 1 (HIV-1) replication have been investigated. 20 HIV-1-infected patients with mean CD4+ T cell count of 298/microl, plasma viral load of 4.7 log10 copies/ml and naive for protease inhibitors (PI) were studied during12 months of HAART. An increased number of both CD4+ and CD8+ naive T cells and a normalization of the frequency of CCR5- and CXCR4-expressing CD4+ T cells were readily observed after starting therapy. Single cell analysis of cytokine production after 12 months of HAART showed an increased number of interleukin (IL)-2-, but not IL-4- and (IFN)-gamma-, producing T cells and a decreased percentage of CD8+ IFN-gamma + cells. A correlation between the frequency of IFN-gamma-producing T cells and that of memory, CCR5+ and CD95+ T cells was demonstrated in both CD4+ and CD8+ subsets. The diversity of T cell receptor (TCR) variable beta (BV) chain repertoire significantly increased after 12 months of HAART within the CD4+ but not the CD8+ T cell subset. However, the level of perturbation of the third complementarity-determining region (CDR3), was not significantly modified by effective therapy. The number of anti-HIV Gag and Pol cytotoxic T lymphocytes precursors (CTLp) decreased during HAART and highly correlated with the CD8 IFN-gamma response. Ameliorated clinical conditions were observed in all patients in absence of any opportunistic infections during all the study period. These observations indicate that a better restoration of immunity may be obtained in patients starting HAART at less advanced stages of the disease.

Activated parathyroid hormone/parathyroid hormone-related protein receptor in osteoblastic cells differentially affects cortical and trabecular bone

Parathyroid hormone (PTH), an important regulator of calcium homeostasis, targets most of its complex actions in bone to cells of the osteoblast lineage. Furthermore, PTH is known to stimulate osteoclastogenesis indirectly through activation of osteoblastic cells. To assess the role of the PTH/PTH-related protein receptor (PPR) in mediating the diverse actions of PTH on bone in vivo, we generated mice that express, in cells of the osteoblastic lineage, one of the constitutively active receptors described in Jansen's metaphyseal chondrodysplasia. In these transgenic mice, osteoblastic function was increased in the trabecular and endosteal compartments, whereas it was decreased in the periosteum. In trabecular bone of the transgenic mice, there was an increase in osteoblast precursors, as well as in mature osteoblasts. Osteoblastic expression of the constitutively active PPR induced a dramatic increase in osteoclast number in both trabecular and compact bone in transgenic animals. The net effect of these actions was a substantial increase in trabecular bone volume and a decrease in cortical bone thickness of the long bones. These findings, for the first time to our knowledge, identify the PPR as a crucial mediator of both bone-forming and bone-resorbing actions of PTH, and they underline the complexity and heterogeneity of the osteoblast population and/or their regulatory microenvironment.

Six novel MEN1 gene mutations in sporadic parathyroid tumors

We report nine mutations of the multiple endocrine neoplasia type 1 (MEN1) gene in sporadic parathyroid adenomas. Six of them have not previously been described: E60X, P32R, 261delA, 934+2T-->G, S443P, and 1593insC. The tissue samples were initially submitted to LOH analysis at 11q13 followed by SSCP screening of LOH-positive samples. Mutations were identified by direct sequencing and subcloning. Three (E60X, P32R, and 261delA) were in exon 2, one (934+2bp) in the splice junction of exon 5, one (S443P) in exon 9, and one (1593insC) in exon 10. The 3 mutations in exon 2 were associated with loss and/or creation of a restriction site. The corresponding germline sequence of the MEN1 gene was normal. Most mutations would likely result in a nonfunctional menin protein, and therefore in the loss of a tumor suppressor protein.

Decreased T cell apoptosis and T cell recovery during highly active antiretroviral therapy (HAART)

T cell apoptosis represents a common mechanism of T cell depletion in HIV-1-infected individuals reflecting maturational and functional T cell abnormalities either directly or indirectly induced by the virus. In the present study, the effects of highly active antiretroviral therapy (HAART) on the spontaneous apoptosis of distinct T cell subsets were investigated during a 6-month follow-up in a cohort of HIV-1-infected individuals with CD4(+) cell counts between 100 and 500 cells/microliter and plasma HIV-1 RNA levels >/=10, 000 copies/ml. We determined that the rapid and sustained increase of both naive (CD45RA(+)CD62L(+)) and memory (CD45R0(+) and CD45RA(+)/CD62L(-)) CD4(+) and, to as lesser extent, CD8(+) T cells in peripheral blood was associated with a significant decrease of apoptotic CD4(+) and CD8(+) as well as CD3(+)CD4(-)CD8(-) T cells. Among CD4(+) lymphocytes, at enrollment, the highest frequency of apoptotic cells was observed within the memory compartment, as defined by CD45R0 expression. During HAART, however, the frequency of CD4(+)CD45R0(+) apoptotic T cells progressively decreased in association with a significant downregulation of surface activation markers that indicated decreased levels of systemic immune stimulation. These results indicate that effective viral suppression can contribute to progressive normalization of maturational and functional T cell abnormalities responsible for the high levels of T cell apoptosis in HIV-1-infected individuals. This, in turn, may contribute to a reduced rate of T cell loss and immune reconstitution during HAART.

T cell receptor repertoire and function in patients with DiGeorge syndrome and velocardiofacial syndrome

DiGeorge syndrome (DGS) and velocardiofacial syndrome (VCFS) are associated with chromosome 22q11.2 deletion. Limited information is available on the T cell receptor (TCR) Vbeta repertoire. We therefore investigated TCR Vbeta families in lymphocytes isolated from blood and thymic samples of seven patients with DGS and seven patients with VCFS, all with 22q11.2 deletion. We also studied activities related to TCR signalling including in vitro proliferation, anti-CD3-induced protein tyrosine phosphorylation, and susceptibility to apoptosis. Reduced CD3+ T cells were observed in most patients. Spontaneous improvement of T cell numbers was detected in patients, 3 years after the first study. Analysis of CD4+ and CD8+ TCR Vbeta repertoire in peripheral and thymic cells showed a normal distribution of populations even if occasional deletions were observed. Lymphoproliferative responses to mitogens were comparable to controls as well as anti-CD3-induced protein tyrosine phosphorylation. Increased anti-CD3-mediated apoptosis was observed in thymic cells. Our data support the idea that in patients surviving the correction of cardiac anomalies, the immune defect appears milder than originally thought, suggesting development of a normal repertoire of mature T cells.

HIV type 1-induced inhibition of CD45 tyrosine phosphatase activity correlates with disease progression and apoptosis, but not with anti-CD3-induced T cell proliferation

The tyrosine phosphatase CD45 is a key positive element in multiple lymphocyte signaling pathways. To understand the contribution of CD45 to HIV-1-induced T cell hyporesponsiveness and apoptosis we evaluated the CD45-associated tyrosine phosphatase activity of lymphocytes from patients with different stages of HIV-1 disease and compared it with CD45 expression, spontaneous and Fas-induced apoptosis, anti-CD3-induced T cell proliferation, distribution of CCR5 delta32/wt, and cytokine production. The proliferative response to anti-CD3 as well as the CD45-associated phosphatase activity were significantly reduced in progressors. In long-term nonprogressors (LTNPs) the proliferative response to anti-CD3 was also diminished, although to a lesser extent, while the tyrosine phosphatase activity was not significantly impaired. One-third of LTNPs were found positive for the 32-bp deletion of the CCR5 gene. This mutation had no effects on anti-CD3 proliferative response or CD45 phosphatase activity. A significant reduction in IL-2 and IFN-gamma was observed in both LTNPs and in normal progressors, whereas IL-4 production was significantly decreased only in progressors. Last, we observed a significant correlation between CD45 phosphatase activity and apoptosis. We therefore conclude that the impairment of CD45 tyrosine phosphatase activity correlates with disease progression and the level of T cell apoptosis, but not with anti-CD3-induced T cell proliferation. Moreover, we suggest that evaluation of CD45 tyrosine phosphatase activity may represent an additional tool with which to assess disease progression.

CCR5 and CXCR4 chemokine receptor expression and beta-chemokine production during early T cell repopulation induced by highly active anti-retroviral therapy

Expression of chemokine receptors and beta-chemokine production by peripheral blood mononuclear cells (PBMC) were determined in HIV-1-infected individuals before and after highly active anti-retroviral therapy (HAART) and their relationship to viral load, T cell phenotype and the expression of immunological activation markers was examined. We found that the expression of CCR5 is up-regulated in HIV-1-infected individuals while CXCR4 appears down-regulated on both CD4 and CD8 T cells compared with normal controls. These alterations are associated with the high levels of viral load. In addition, a relationship was observed between the degree of immune activation and chemokine receptor expression on T cells. However, after 3 months of combined anti-retroviral regimen, expression of CXCR4 significantly increased while CCR5 decreased when compared with pretherapy determinations. This was seen in strict association with a dramatic decrease of viral load and an increase of both CD45RA+/CD62L+ (naive) and CD45RA-/CD62L+ or CD45RA+/CD62L- (memory) T cells accompanied by a significant decrease of the expression of immune activation markers such as HLA-DR and CD38. At enrolment, both spontaneous and lectin-induced RANTES, macrophage inflammatory protein-1alpha (MIP-1alpha) and MIP-1beta production by PBMC were higher in HIV-1-infected individuals compared with normal controls, although differences for MIP-1beta were not statistically significant. However, RANTES and MIP-1alpha production decreased during HAART at levels closer to that determined with normal controls, while MIP-1beta production was less consistently modified. These data indicate that the expression of chemokine receptors CCR5 and CXCR4 and the production of beta-chemokines are altered in HIV-infected individuals, and suggest that their early modifications during HAART reflect both the peripheral redistribution of naive/memory T cell compartments and the decrease in levels of T cell activation. Such modifications in the expression of host determinants of viral tropism and the production of anti-viral molecules may play a role in the emergence of virus variants when a failure of HAART occurs.

Apoptosis in asymptomatic HIV-1 seropositives immunized with HIV-1 env glycoprotein (gp160): effects of administration of Zidovudine in vivo and interleukin-2 in vitro

In this paper we report the effects of VaxSyn (Protein Sciences Corp.) immunization on spontaneous apoptosis occurring in vitro after culture of PBMC in medium alone in 30 HIV-seropositive patients enrolled in a double-blind clinical trial that included three groups: treatment with VaxSyn, AZT and VaxSyn, and AZT. Our data show no significant modifications in the levels of apoptosis observed in the three groups over the long-term follow-up (up to 720 days). This was not associated with any significant modifications in other clinical or immunological features. However, analysis of apoptosis performed shortly after the first immunization (at days 3 and 7) showed a significant reduction in the rate of apoptosis in patients receiving AZT and AZT and VaxSyn, as compared with patients receiving VaxSyn alone (30.42 +/- 2.52 SE at day 0 and 23.74 +/- 1.84 at day 3; p = 0.039). Our data also indicate that addition of IL-2 in vitro had a significant inhibitory effect on mortality in all the randomization groups, especially in those receiving AZT (alone or in combination with VaxSyn).

IL-10 production and CD40L expression in patients with common variable immunodeficiency

The authors studied CD40 ligant (CD40L) expression and interleukin-10 (IL-10) production in 16 patients with common variable immunodeficiency (CVI). Mean CD40L expression, determined by using cytofluorimetry, and measured as the mean fluorescence intensity following stimulation of peripheral blood mononuclear cells (PBMC) with phorbol myristate acetate (PMA) and calcium ionophore in 12 patients, was comparable to that of controls. However, three CVI patients showed fluorescence intensity in stimulated cells below 2 standard deviations of normal donors' mean and two other patients had only a slight increase of stimulated versus unstimulated cells (< 10 channels). IL-10 production after stimulation of PBMC with both anti-CD3 or anti-CD3 plus PMA gave similar results in CVI patients and normal controls. In vitro stimulation of PBMC with anti-CD40 and various combinations of cytokines (IL-2, IL-4 and IL-10) induced IgG production above 100 ng/ml in one CVI patient out of 13 tested. The data suggest that alterations of IL-10 production are unlikely to play a major role in the pathogenesis of impaired IgG production in most CVI patients. CD40L appears to be normally expressed in two thirds of CVI patients, but it may be functionally defective.

Proliferative responses to PHA, anti-CD3 and antigens in patients with lymphoproliferative disease of granular lymphocytes. Mannoproteins of Candida albicans induce proliferation and cytotoxicity

In this paper we investigated the lymphoproliferative and cytotoxic responses of peripheral blood mononuclear cells (PBMC) of patients affected with lymphoproliferative disease of granular lymphocytes of T cell origin to mitogens and antigens. Most patients with lymphoproliferative disease of granular lymphocytes (LDGL) showed a severely impaired PBMC proliferative capacity in response to phytohemagglutinin, anti-CD3 and tetanus toxoid, an impairment that, in the case of anti-CD3 response, appears to be related to a defect of phosphorylation in response to triggering. In contrast, at least 50% of the patients had normal proliferation in response to a mannoprotein fraction purified from Candida albicans. These data suggest that some CD3+ GL from LDGL patients, that usually respond poorly to proliferative stimuli in vitro, can be triggered to perform these functions by candidal antigens.

HCV infection in a patient with hyper IgM syndrome

The association between an acquired form of hyper-IgM syndrome and a chronic hepatitis C virus (HCV) infection in a 71-year-old female patient is described. Both diseases were diagnosed at the age of 58 years. She was started on intramuscular and then intravenous immunoglobulin replacement therapy. HCV RNA was detected in 1992. The patient remained in well-balanced clinical condition until 1994, when total and specific anti-HCV IgM levels increased and the patient developed an IgM kappa monoclonal gammopathy. Adherent cells and B cells were HCV RNA positive, while T cells were HCV RNA negative. Anti-IgM reactivity was specifically directed to the core antigen of the HCV. The patient we describe showed a picture of a late-onset form of hypogammaglobulinemia with a progressive increase in IgM antibodies, possibly due to the concomitant HCV infection. It is possible that the immunodeficiency might also result from the HCV infection, with formation of specific antibodies belonging to the IgM class, and that the worsening of the clinical condition may be directly related to the persistent viral infection.

Hepatitis C virus infection in Italian patients with hypogammaglobulinemia

We investigated the presence of hepatitis C virus (HCV) infection in 58 patients with humoral immunodeficiencies. Forty-three of these patients had common variable immunodeficiency (CVI), 2 had sporadic hyperimmunoglobulin M (HIM) syndrome, 2 had immunoglobulin G subclass deficiency, 4 had ataxia-telangiectasia (AT), and 7 had X-linked agammaglobulinemia (XLA). Patients with late-onset hypogammaglobulinemia (those with CVI, HIM, or immunoglobulin G subclass deficiency) had a 38.2% prevalence of HCV infection. In patients with XLA or AT, HCV infection was not detectable. Most of the HCV-infected patients had persistent viremia, with histologic findings of chronic hepatitis. Although patients positive for HCV ribonucleic acid (RNA) had received several lots of immunoglobulin, we were unable to detect any correlation between the time that alanine aminotransferase levels increased and the time that intravenous immunoglobulin therapy was given, except in one patient with CVI. Moreover, we found no differences in the number of blood transfusions, surgical procedures, or administrations of intravenous or intramuscular immunoglobulin between HCV RNA-positive and HCV RNA-negative groups. We concluded that: (1) the incidence of HCV infection in patients with hypogammaglobulinemia is much higher than that reported in the Italian general population; (2) although patients with hypogammaglobulinemia have persistent viremia, they do not show an aggressive course of HCV disease, nor does hepatocarcinoma develop; and (3) intravenous immunoglobulins are only one of several possible causes of HCV transmission in patients with humoral immunodeficiencies.

HCV infection in patients with primary defects of immunoglobulin production

We tested for infection with hepatitis C virus (HCV) in 58 patients affected by humoral immunodeficiencies: 43 common variable immunodeficiency (CVI), two hyper IgM syndrome (HIM), two IgG subclass deficiency, four ataxia-telangiectasia (AT), and seven X-linked agammaglobulinaemia (XLA). While the assessment of serum specific HCV antibodies in some of these patients was not informative because of the impairment in specific antibody production, the reverse transcriptase polymerase chain reaction (RT-PCR) assay used to detect serum HCV RNA was a useful method for diagnosing infection. We found that 38% of late onset hypogammaglobulinaemic patients (CVI, HIM or IgG subclass deficiency) had evidence of HCV infection. HCV infection was not detectable in patients with XLA or AT. The majority of our patients had persistent viraemia, and those who underwent liver biopsy showed histological findings of chronic hepatitis. Moreover, we could demonstrate in vitro that eight of 18 HCV-infected patients were actively producing anti-HCV antibodies, despite their impaired antibody production. The high rate of HCV infection in hypogammaglobulinaemic patients could be related to several nosocomial routes of transmission, including intravenous immune globulin administration. Despite the persistent viremia only two patients had cirrhosis and none had hepatocarcinoma.

Immunodeficiency with hyperimmunoglobulinemia M in two female patients is not associated with abnormalities of CD40 or CD40 ligand expression

The immunologic defect in X-linked immunodeficiency and hyperimmunoglobulinemia M (HIM) are related to defective expression of the CD40 ligand (CD40L). We have studied two female patients with HIM to evaluate the role of CD40/CD40L in the pathogenesis of impaired immunoglobulin switching. In addition to recurrent infections characteristic of humoral immunodeficiencies, the two patients had chronic hepatitis caused by type C virus. Phenotypic characterization of peripheral blood mononuclear cells showed a similar picture in both patients, with a reduction in the absolute numbers of CD4 cells and increased numbers of CD8 and CD3/DR cells. B cells (CD19+) were reduced in one patient, but CD40 was expressed on all CD19+ cells in both patients. The expression of CD40L was normal on peripheral blood mononuclear cells from the two patients with HIM on both resting and stimulated cells. The combination of anti-CD40 and cytokines (interleukin-2, interleukin-4, and interleukin-10) was able to restore proliferative capacity to anti-IgM. Peripheral blood mononuclear cells from the two patients with HIM showed a high spontaneous production of IgM in vitro and no production of IgG or IgE. Our data suggest that the defect of isotype switching in female patients with HIM is not related to defective expression of the CD40/CD40L receptor system. A possible role for chronic hepatitis C virus infection in the pathogenesis of the disease is suggested by the detection of specific production of anti-hepatitis C virus IgM.

Apoptosis-related mortality in vitro of mononuclear cells from patients with HIV infection correlates with disease severity and progression

Peripheral blood mononuclear cells (PBMC) from 103 HIV-infected patients were tested for their mortality rate (MR) when incubated in vitro for 3 days in a culture medium. MR was related to apoptosis as shown by DNA analysis and morphological evaluation of ethidium bromide-stained PBMC by flow cytometry. MR was significantly higher in patients in CDC stage IV as compared to patients in stage II or III (p = 0.017). MR was also higher in patients with low CD4 cells/mm3 (p = 0.014 for patients with < 400 cells; p = 0.001 for patients with < 200 CD4 cells/mm3) and with low percentage of CD4 cells (p = 0.001 for patients with < 10% of CD4 cells). A significant negative correlation was observed between MR and both absolute numbers or percentages of CD4 cells (p < 0.001). The addition of interleukin-2 (IL-2) and fibro-blast-conditioned medium (FCM) to the cultures significantly reduced MR. However, the ability of both IL-2 and FCM to preserve viability was significantly associated with p24 negativity. Clinical and immunological follow-up was available for 60 patients for a mean period of 26 months. MR at the beginning of the study was significantly higher in the group of patients who clinically progressed (according to the CDC classification) or died during the follow-up (p < 0.0001). Our data suggest that MR correlates with both disease severity and progression and that MR is directly related to the depletion of CD4 cells in cultures.(ABSTRACT TRUNCATED AT 250 WORDS)

Tyrosine phosphorylation pathway is involved in interferon-gamma (IFN-gamma) production; effect of sodium ortho vanadate

The molecular mechanisms regulating IFN-gamma production have yet to be well characterized. We describe here how treatment of activated cultures of peripheral blood mononuclear cells (PBMC) with the phosphotyrosine phosphatases (PTP) inhibitor sodium ortho vanadate results in greatly enhanced IFN-gamma production. Conversely, cellular proliferation of the same cultures is profoundly inhibited by treatment with vanadate, while the expression of IL-2R and DR molecules on activated lymphocytes remains substantially unmodified. Increased IFN-gamma production, but not inhibition of cellular proliferation, was also observed in mitogen-activated vanadate-treated Jurkat cells. On the other hand, IFN-gamma production induced in cultures of PBMC treated or not with vanadate, was strongly inhibited by incubation with the protein tyrosine kinase (PTK) inhibitor herbimycin A. As a result of the inhibited phosphatase activity, substrates for PTK become hyperphosphorylated on tyrosine residues, as shown by Western blot analysis of cell lysates from cultures of PBMC treated with vanadate. We suggest that the tyrosine phosphorylation pathway plays a role in regulating IFN-gamma production.

Fibroblast-derived factors preserve viability in vitro of mononuclear cells isolated from subjects with HIV-1 infection

OBJECTIVE

Peripheral blood mononuclear cells (PBMC) from HIV-infected subjects have an increased mortality rate (MR) when incubated in vitro for 3 days in a culture medium. We have previously shown that fibroblast-conditioned medium (FCM) can preserve viability, without significant activation, of human lymphocytes in vitro. We therefore tested the ability of two FCM and other factors to reduce spontaneous MR in HIV-positive PBMC.

METHODS

PBMC were cultured for 3 days in control medium and medium supplemented with FCM or recombinant cytokines [interleukin (IL)-2, IL-6, IL-7, granulocyte macrophage colony-stimulating factor]. Cells viable at day 3 were counted in a cytofluorimeter after staining with ethidium bromide. DNA was extracted from the cultures and evaluated for the presence of low molecular weight fragmentation.

RESULTS

The MR of PBMC from 51 HIV-positive subjects and from 21 healthy controls were 30.1 and 9.5%, respectively (P < 0.0001). The MR was higher in 40 patients with a CD4+ lymphocyte count < 400 x 10(6)/l than in subjects with a count > 400 x 10(6)/l (32.84 versus 20.96%; P = 0.047). IL-2 and FCM significantly reduced MR in HIV-positive subjects (MR: 17.8 and 20.4%; P: < 0.001 and 0.005, respectively). This effect was more evident in subjects with a CD4+ lymphocyte count < 400 x 10(6)/l and in subjects with negative p24 antigenaemia. Cellular proliferation accounts for increased survival in IL-2-supplemented cultures but not in those with FCM. DNA was extracted from fresh PBMC and cells cultured for 3 days for 22 HIV-positive cases. DNA degradation was documented and bands related to an apoptotic mechanism of death observed, especially in subjects with more advanced disease.

CONCLUSIONS

Our data suggest that FCM inhibits accelerated cell death in vitro of PBMC isolated from HIV-positive patients.

Immunization of Macaca fascicularis with inactivated SIV preparations: challenge with human- or monkey-derived SIV and the effects of a longer immunization schedule

In cynomolgus monkeys, we compared two human-derived SIVmac251 whole virus vaccines, a long vs short immunization schedule, and two different challenge viruses. Both vaccines induced protection after challenge with human-derived SIVmac251/32H. There was no difference between the two schedules of immunization. Seven monkeys, five of which were protected following the first challenge, were reboosted and rechallenged with monkey-derived SIVmac251, but no protection was observed. The titers of anti-human cell or -SIV neutralizing antibodies were not related to protection.

Vaccination of pregnant cynomolgus monkeys with whole formalin-inactivated SIVmac251

Five pregnant (two to three and one-half months) Macaca fascicularis seroconverted following immunization with sucrose-gradient purified and formalin-inactivated whole simian immunodeficiency virus (SIVmac251). No untoward effects on fetal maturation were observed during the immunization of the mothers. Antibodies to SIVmac251 (also those with in vitro neutralizing activity) were passively transferred to the offspring but disappeared within two to six months after birth. Antibodies to env glycoprotein (gp130) lasted longer than those against viral gag proteins (p26,p60).

Alterations of T-cell functions during Friend leukemia complex infection: defective signal transduction?

Proliferative and interleukin responses to T-cell mitogens such as concanavalin A (Con A) were rapidly and progressively reduced in BALB/c mice infected with the Friend leukemia complex (FLC) or its helper, Friend murine leukemia virus (F-MuLV). In contrast, a combination of the protein kinase C activator phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) and the Ca++ ionophore A23187 elicited a normal lymphoproliferative response up to 8 days postinfection (p.i.) and normal interleukin-2 (IL-2) and interferon-gamma responses up to day 14 p.i. Exogenous IL-2 failed to restore the lymphoproliferative response of infected cells regardless of the stimulation used. These results showed that the T-cell deficits may be at least partly attributable to a derangement of the signal transduction pathway leading to activation. Spleen cells passed through nylon wool columns reacquired a normal responsiveness to Con A +/- TPA up to 14 days p.i. The latter finding suggests that the alterations in signal transduction are not caused by primary defect of the responder-T cells but may result from an extrinsic suppressive mechanism.

Role of interferon in lethality and lymphoid atrophy induced by Coxsackievirus B3 infection in mice

To assess the importance of interferon (IFN) in the pathology of coxsackievirus B3 (CVB-3) infection, we evaluated both mortality rate and lymphoid involution in young adult BALB/C mice infected with lethal doses of the virus and treated either with anti-IFN antibody or with murine IFN-alpha/beta. Administration of antibody to IFN caused a profound worsening of the pathology and an increase in the mortality rate in infected animals. Treatment with murine IFN exerted a significant ameliorative effect on lethality when administered concomitantly with or soon after virus infection. The extent of this protection was correlated with the plasma levels of exogenous or endogenous IFN at 6 h postinfection, whereas no correlation with IFN titers was found later. The effects of IFN apparently were not directly mediated by antiviral effects, because at the times studied, no relation was found between IFN levels and virus titers, at least in the plasma of the infected animals. Lymphoid atrophy, assessed by measuring spleen weight, was only partially reversed by early IFN treatment. These data suggest that IFN production is critical during the early phases of infection, whereas it does not seem to play a significant protective role at later stages.