Immunomodulatory effects of 1,25-dihydroxyvitamin D3 on TH1/TH2 cytokines in inflammatory bowel disease: an in vitro study

Crohn's disease (CD) is associated with a higher type-1-helper T cell (Th1) cytokine expression, whereas ulcerative colitis (UC) appears to express a modified Th2 response. In addition to its classic role in calcium homeostasis, calcitriol, the hormonal active form of vitamin D, exerts immunoregulatory effects such as modulation of Th1/Th2 cytokines. Therefore, calcitriol administration could modify immune dysfunction in CD and UC. Nine patients with UC (M/F: 5/4; mean age 47 years, remission(R)/active(A) disease: 7/2), 8 patients with CD (M/F: 2/6; mean age 36, R/A 5/3) and 6 healthy controls (HC) (M/F: 3/3, mean age 4) were enrolled. Peripheral blood was collected after a drug-washout of 15 days and peripheral blood mononuclear cells were stimulated with mitogens alone or in the presence of physiological concentrations of calcitriol (100 pg/ml). Type 1 (IL-2, TNF-alpha, IFN-gamma) and type 2 (IL-10) cytokine production was assayed on supernatants by ELISA. Compared to HC, TNF-alpha production was significantly higher both in UC (p=0.0002) and CD (p=0.0001) patients, at baseline and after incubation with calcitriol (UC p=0.0003, CD p=0.0009). The effects of calcitriol incubation were: 1) reduced IFN-gamma (p=0.024) and increased IL-10 (p=0.06) production in UC patients; 2) reduced TNF-alpha production in CD (p=0.032); 3) no significant effects in HC. Calcitriol increased, albeit not significantly, IL-10 production in UC compared to CD patients (p=0.09). These results suggest an important modulatory role of vitamin D in the Th1/Th2 immune response. The observation that the effect of this modulation was different in CD compared to UC patients provides an interesting area of research into the pathogenesis and treatment of these inflammatory conditions.

Immune modulation by lactoferrin and curcumin in children with recurrent respiratory infections

The clinical and immunologic effects of lactoferrin and curcumin (LC) oral supplementation were examined in healthy children with recurrent respiratory tract infections. Infections were reduced in children receiving LC. Immunologic analyses showed that LC supplementation resulted in a significant skewing of CD8+T lymphocytes maturation. Additionally: 1) CD14+, toll like receptor (TLR) 2-expressing cells augmented (p= 0.005) whereas CD14+/TLR4+ diminished (p= 0.004); and 2) IL10 production by CD14+ cells was reduced in children receiving LC. LC supplementation results in immune modulation and could be clinically beneficial.

T lymphocyte maturation is impaired in healthy young individuals carrying trisomy 21 (Down syndrome)

Cytokine production, immune activation, T lymphocytes maturation, and serum IL-7 concentration were examined in 24 youngsters with Down syndrome and no acquired diseases (healthy Down syndrome [12 prepubertal, 13 pubertal]) and 42 age- and gender-matched controls (20 prepubertal, 22 pubertal). Results showed that a complex immune and impairment is present in healthy individuals with Down syndrome in whom interferon gamma, interleukin (IL) IL-10 production, as well as serum IL-7 concentrations and activation markers-bearing T lymphocytes were significantly augmented. Additionally, a complex skewing of post-thymic lymphocyte maturation pathways was observed in patients: significant reduction of CD4+ and CD8+ naive (RA+CCR7+) lymphocytes, significant increase of CD4+ and CD8+ central memory (RA-CCR7+), and terminally differentiated (TD) (RA+CCR7-) lymphocytes.

HLA and autoimmune digestive disease: a clinically oriented review for gastroenterologists

OBJECTIVES

The human leukocyte antigen (HLA) system includes genes involved in graft-vs-host rejection and in immune response. The discovery that HLAs are associated with several diseases led to appealing developments both in basic biomedical research and in clinical medicine, and offered the opportunity to improve the understanding of pathogenesis and classification of diseases, as well as to provide diagnostic and prognostic indicators. The aim of this article is to review the association between HLA alleles and autoimmune digestive disease and its current relationship with modern HLA nomenclature and clinical practice.

METHODS

Articles dealing with the association between HLAs and autoimmune digestive disease (including celiac disease, inflammatory bowel disease, autoimmune hepatitis, sclerosing cholangitis and primary biliary cirrhosis) were searched for using Pubmed and SCOPUS databases from earliest records to January 2008.

RESULTS

The review has provided two sections. In the first, we explain the basic principles of HLA structure, function, and nomenclature, as an introduction to the second section, which describes current associations between HLA alleles and digestive diseases. The clinical implications of each HLA association are critically discussed. Actually, a clinical role for HLA typing is suggested for only a few conditions, e.g., celiac disease.

CONCLUSIONS

The knowledge of current HLA nomenclature and of its association with some digestive diseases such as celiac disease can be useful in clinical practice for diagnostic and prognostic purposes. This can avoid improper HLA typing as well as stressing the need for further studies on other possible clinical applications.

Treatment of periodontal disease results in improvements in endothelial dysfunction and reduction of the carotid intima-media thickness

Several cohort studies reported a relation of cardiovascular events and periodontal disease. In particular, Porphyromonas gingivalis is associated with the development of atherosclerotic plaques. We verified in a longitudinal study whether inflammation biomarkers, endothelial adhesion molecules, leukocyte activation markers, and intima-media thickness could be beneficially modified by periodontal treatment alone. Thirty-five otherwise healthy individuals affected by mild to moderate parodontopathy were enrolled in the study. Echo-Doppler cardiography of the carotid artery, fluorescence-activated cell sorting analyses on lymphocytes and monocytes, and plasma inflammatory indices were evaluated at baseline and at multiple time points after the periodontal treatment. Results showed that inflammation biomarkers were abnormally increased at baseline. Periodontal treatment resulted in a significant reduction of the total oral bacterial load that was associated with a significant amelioration of inflammation biomarkers and of adhesion and activation proteins. Notably, intima-media thickness was significantly diminished after treatment. Inflammatory alterations associated with the genesis of atherosclerotic plaques are detected in otherwise healthy individuals affected by parodontopathy and are positively influenced by periodontal treatment. Reduction of oral bacterial load results in a modification of an anatomical parameter directly responsible for atherosclerosis. These results shed light on the pathogenesis of atherosclerosis and could have practical implications for public health.

Fully immunocompetent CD8+ T lymphocytes are present in autologous haematopoietic stem cell transplantation recipients despite an ineffectual T-helper response

BACKGROUND

Reduced CD4 T lymphocytes counts can be observed in HIV infection and in patients undergoing autologous haematopoietic stem cell transplantation (ASCT). Nevertheless, whereas opportunistic infections (OI) are frequent in HIV-infected individuals with low cell counts, OI are uncommon in ASCT patients.

METHODOLOGY/PRINCIPAL FINDINGS

To verify whether this observation could be secondary to intrinsic HIV-correlated T cell defects, we performed in-depth immunologic analyses in 10 patients with comparable CD4 counts in whom lymphopenia was secondary either to HIV-infection or ASCT-associated immunosuppressive therapy and compared them to age-matched healthy subjects. Results showed the presence of profound alterations in CD4+ T lymphocytes in both groups of patients with respect to healthy controls. Thus, a low percentage of CCR7+ CD4+ T cells and a compensative expansion of CD45RA-CCR7- CD4+ T cells, a reduced IL-2/IFN-gamma cytokine production and impaired recall antigens-specific proliferative responses were detected both in ASCT and HIV patients. In stark contrast, profound differences were detected in CD8+ T-cells between the two groups of patients. Thus, mature CD8+ T cell prevailed in ASCT patients in whom significantly lower CD45RA-CCR7- cells, higher CD45RA+CCR7- CD8+ cells, and an expansion of CCR7+CD8+ cells was detected; this resulted in higher IFN-gamma +/TNFalpha production and granzyme CD8+ expression. The presence of strong CD8 T cells mediated immune responses justifies the more favorable clinical outcome of ASCT compared to HIV patients.

CONCLUSION/SIGNIFICANCE

These results indicate that CD8 T cells maturation and functions can be observed even in the face of a profound impairment of CD4+ T lymphocytes in ASCT but not in HIV patients. Primary HIV-associated CD8 defects or an imprinting by an intact CD4 T cell system in ASCT could justify these results.

CD4+CD25+FoxP3+PD1- regulatory T cells in acute and stable relapsing-remitting multiple sclerosis and their modulation by therapy

The intracellular expression of the programmed death receptor 1 (PD1) identifies a subset of naive T(reg) cells with enhanced suppressive ability; antigen stimulation results in the surface expression of PD1. Because the role of T(reg) impairments in multiple sclerosis (MS) is still contradictory, we analyzed naive PD1- and PD1+ T(reg) cells in peripheral blood and cerebrospinal fluid (CSF) of relapsing-remitting multiple sclerosis (RR-MS) patients and of healthy control subjects. Results showed that 1) CSF PD1- T(reg) cells were significantly augmented in MS patients; 2) PD1- T(reg) cells were significantly increased in the peripheral blood of patients with stable disease (SMS) compared to those with acute (AMS) disease, and in patients responding to glatiramer acetate (COPA) compared to AMS- and COPA-unresponsive patients; and 3) PD1+ T(reg) cells were similar in CSF and peripheral blood of all groups analyzed. PD1- T(reg) cells were not increased in the peripheral blood of interferon-beta (IFNbeta) -responsive patients, but the suppressive ability of T(reg) cells was significantly higher in SMS and in COPA- or IFNbeta-responsive compared to AMS- and COPA-unresponsive individuals. The data herein suggest that PD1- T(reg) cells play a pivotal role in MS and offer a biological explanation for disease relapse and for the mechanism associated with response to COPA and IFNbeta.

The mucosae-associated epithelial chemokine (MEC/CCL28) modulates immunity in HIV infection

Background

CCL28 (MEC) binds to CCR3 and CCR10 and recruits IgA-secreting plasma cells (IgA-ASC) in the mucosal lamina propria (MLP). Mucosal HIV-specific IgA are detected in HIV-infection and exposure. The CCL28 circuit was analyzed in HIV-infected and-exposed individuals and in HIV-unexposed controls; the effect of CCL28 administration on gastrointestinal MLP IgA-ASC was verified in a mouse model.

Methodology/Findings

CCL28 was augmented in breast milk (BM) plasma and saliva of HIV-infected and –exposed individuals; CCR3+ and CCR10+ B lymphocytes were increased in these same individuals. Additionally: 1) CCL28 concentration in BM was associated with longer survival in HIV vertically-infected children; and 2) gastro-intestinal mucosal IgA-ASC were significantly increased in VSV-immunized mice receiving CCL28.

Conclusions

CCL28 mediates mucosal immunity in HIV exposure and infection. CCL28-including constructs should be considered in mucosal vaccines to prevent HIV infection of the gastro-intestinal MLP via modulation of IgA-ASC.

Apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G: a possible role in the resistance to HIV of HIV-exposed seronegative individuals

Apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G (APOBEC3G), a human cytidine deaminase, is a potent inhibitor of HIV replication. To explore a possible role of this protein in modulating in vivo susceptibility to HIV infection, we analyzed APOBEC3G expression in HIV-exposed seronegative individuals, HIV-seropositive patients, and healthy control subjects. The results showed that the expression of APOBEC3G is significantly increased in peripheral blood mononuclear cells (PBMCs)--mainly CD14(+) cells--and in cervical tissues of HIV-exposed seronegative individuals. Higher APOBEC3G expression correlated with a reduced susceptibility of PBMCs to in vitro infection with the HIV-1(Ba-L) R5 strain. APOBEC3G could be important in modulating in vivo susceptibility to sexually transmitted HIV infection.

An immunological comparison of third companion in advanced drug-naive HIV-infected patients

An immunological comparison of three different third companions (abacavir [ABC], efavirenz [EFV], ritonavir-boosted indinavir [IDVr]) on a backbone of either zidovudine plus didanosine (AZT/ddI) or zidovudine plus lamivudine (AZT/3TC) was performed in 76 HIV-infected, advanced-naive patients. Baseline median CD4 count and viremia were 217/microL and 238,301 copies/mL, respectively. Immunologic parameters were measured at baseline and after months of therapy. By the end of the study, 36 patients (mostly in the protease inhibitor [PI]-containing arms) had dropped out of the study; 22/36 cases of drop out were due to tolerability issues. All regimens resulted in increases in CD4 counts, with the most solid changes seen in patients using ABC as a third companion. Median HIV plasma viremia at month 12 was <50 copies/mL, and viremia was undetectable in 26/38 patients (68%). At the end of the study period, HIV antigen- and mitogen-stimulated proliferation overall was better in patients using either of the PI-boosted third companions. In these patients, the strongest down-modulation of activation marker-bearing cells was also observed. Finally, CD8+/28-/CD45RA+ lymphocytes (effector cells) were increased in all groups of patients with the exception of individuals receiving PI-boosted therapies. Results of this pilot study, although very preliminary, suggest that different combinations of antivirals result in a range of effects on immune cell functions. The clinical implications of these results need to be further analyzed in follow-up studies and in larger cohorts of patients.

Effects of Specific Immunotherapy on the B7 Family of Costimulatory Molecules in Allergic Inflammation

The effect of allergen-specific immunotherapy (IT) on Ag presentation and T lymphocyte stimulation was evaluated by verifying the expression of costimulatory molecules in allergic patients. Thus, CD28 and CTLA-4, B7, and B7-H molecules on immune cells, as well as cytokine production, were analyzed in and out of the pollination period in 30 patients allergic to Betulaceae that had or had nor undergone specific IT. Results showed that IT attenuated the increase in the percentage of CD28(+)CD4 T cells and the decrease in the percentage of CTLA-4(+)CD4(+) T cells seen in untreated individuals. CD19(+)/CD80, CD19(+)/CD86(+), and CD14(+)/CD80(+) APCs were significantly augmented during pollination in unvaccinated individuals. B7-H1-expressing monocytes (CD14(+)) and B lymphocytes (CD19) as well as CD14 and CD19 B7-H1(+)/IL-10(+) APC were augmented in Betulaceae Ag-stimulated cell cultures of vaccinated patients independently of pollination, and were further increased in these individuals during pollination. As a result, the IL-10-IFN-gamma ratio in CD4(+), CD14(+), and CD19(+) cells increased in vaccinated patients, but decreased in unvaccinated individuals during pollination. These data clarify the cellular and molecular basis underlying the recent observation that peripheral expansion of IL-10-producing cells is associated with successful IT. B7-H1 could be an optimal target for IT of allergic diseases using mAbs.

Immune activation and normal levels of endogenous antivirals are seen in healthy adolescents born of HIV-infected mothers

Immunological analyses performed in healthy adolescents born of HIV-infected (seroreverters) or healthy mothers (healthy controls; HC) showed that immune activation and a skewing of postthymic differentiation are present in adolescent seroreverters. In-utero HIV exposure results in long-lasting imprinting on the immune system. Alternatively, an immune response naturally more prone to activation could prevent vertical infection. Endogenous antivirals (APOBEC, TRIM5alpha) were comparable in seroreverters and HC, and might not play a role in resistance to vertical HIV infection.

IL-22 participates in an innate anti-HIV-1 host-resistance network through acute-phase protein induction

Certain individuals are resistant to HIV-1 infection, despite repeated exposure to the virus. Although protection against HIV-1 infection in a small proportion of Caucasian individuals is associated with mutant alleles of the CCR5 HIV-1 coreceptor, the molecular mechanism underlying resistance in repeatedly HIV-1-exposed, uninfected individuals (EU) is unclear. In this study, we performed complementary transcriptome and proteome analyses on peripheral blood T cells, and plasma or serum from EU, their HIV-1-infected sexual partners, and healthy controls, all expressing wild-type CCR5. We report that activated T cells from EU overproduce several proteins involved in the innate immunity response, principally those including high levels of peroxiredoxin II, a NK-enhancing factor possessing strong anti-HIV activity, and IL-22, a cytokine involved in the production of acute-phase proteins such as the acute-phase serum amyloid A (A-SAA). Cell supernatants and serum levels of these proteins were up-regulated in EU. Moreover, a specific biomarker for EU detected in plasma was identified as an 8.6-kDa A-SAA cleavage product. Incubation of in vitro-generated myeloid immature dendritic cells with A-SAA resulted in CCR5 phosphorylation, down-regulation of CCR5 expression, and strongly decreased susceptibility of these cells to in vitro infection with a primary HIV-1 isolate. Taken together, these results suggest new correlates of EU protection and identify a cascade involving IL-22 and the acute phase protein pathway that is associated with innate host resistance to HIV infection.

Hiv-specific secretory IgA in breast milk of HIV-positive mothers is not associated with protection against HIV transmission among breast-fed infants

OBJECTIVES

To test whether secretory immunoglobulin A (sIgA) to human immunodeficiency virus (HIV) antigens in breast milk of HIV-positive women is associated with protection against HIV transmission among breast-fed infants.

STUDY DESIGN

Nested, case-control design in which HIV-specific sIgA was measured in breast milk collected from 90 HIV-positive women enrolled in a study in Lusaka, Zambia. Milk samples were selected to include 26 HIV-positive mothers with infected infants (transmitters) and 64 mothers with uninfected infants (nontransmitters).

RESULTS

HIV-specific sIgA was detected more often in breast milk of transmitting mothers (76.9%) than in breast milk of nontransmitting mothers (46.9%, P = .009). There were no significant associations between HIV-specific sIgA in breast milk and other maternal factors, including HIV RNA quantities in breast milk, CD4 count, and plasma RNA quantities.

CONCLUSIONS

HIV-specific sIgA in breast milk does not appear to be a protective factor against HIV transmission among breast-fed infants.

Synergy between mannose-binding lectin gene polymorphisms and supplementation with vitamin A influences susceptibility to HIV infection in infants born to HIV-positive mothers

BACKGROUND

Mannose-binding lectin (MBL-2) allele variants are associated with deficiencies in innate immunity and have been found to be correlated with HIV infection in adults and children.

OBJECTIVE

We tested whether MBL-2 variants among infants born to HIV-positive mothers have an increased susceptibility to HIV.

DESIGN

MBL-2 allele variants were measured among 225 infants born to HIV-positive mothers enrolled in a trial in Durban, South Africa. Mothers of 108 infants were randomly assigned to receive vitamin A and beta-carotene supplementation and 117 to receive placebo. Infants were followed with regular HIV tests to determine rates of mother-to-child HIV transmission.

RESULTS

A high proportion of infants were either homozygous (10.7%) or heterozygous (32.4%) for MBL-2 variants. MBL-2 variants within the placebo arm were associated with an increased risk of HIV transmission (odds ratio: 3.09; 95% CI: 1.21, 7.86); however, MBL-2 variants within the supplementation arm were not associated with an increased risk of transmission (P = 0.04; test of interaction). Among infants with MBL-2 variants, supplementation was associated with a decreased risk of HIV transmission (odds ratio: 0.37; 95% CI: 0.15, 0.91).

CONCLUSION

We observed what appears to be a gene-environment interaction between MBL-2 variants and an intervention with vitamin A plus beta-carotene that is relevant to mother-to-child HIV transmission.

Immunogenicity and effect of a virosomal influenza vaccine on viral replication and T-cell activation in HIV-infected children receiving highly active antiretroviral therapy

In order to evaluate the immunogenicity and the effect of a virosomal influenza vaccine on viral replication and T-cell activation in HIV-infected children receiving highly active antiretroviral therapy (HAART), 29 children infected with HIV-1 vertically (19 primed with a previous influenza vaccination and 10 who were not been immunized against influenza) were immunized with an intramuscular virosome-adjuvanted influenza vaccine. According to the European Agency for Evaluation of Medical Products (EMEA) criteria, the immunogenicity of the vaccine was adequate against all three influenza strains (A H1N1, A H3N2, and B) in the primed children, and against A H1N1 and A H3N2 in the unprimed children. After in vitro stimulation with vaccine antigens, the IFN-gamma levels in the peripheral blood mononuclear cells cultures increased significantly from a baseline level of 103.0 +/- 229.8 pg/ml to a 30-day level of 390.7 +/- 606.3 pg/ml (P < 0.05), with concentrations significantly higher (P < 0.05) in the primed children than in the unprimed children. No increase in plasma HIV-1 RNA or HIV-1 proviral DNA was observed in either subgroup, and the immunophenotype analyses demonstrated that the CD4+ cell counts and percentages, the CD4/CD8 ratio and activated lymphocytes remained stable in either group from baseline to 1 month after each vaccine dose. This study showed that the virosomal influenza vaccine does seem to be immunogenic in the majority of HIV-infected children receiving HAART and does not induce viral replication or T-cell activation. Given the possible influenza-related complications in children infected with HIV, these results support the use of this influenza vaccine in such patients.

Failure to eradicate HIV despite fully successful HAART initiated in the first days of life

Highly active antiretroviral therapy (HAART) started shortly after birth resulted in reversion of human immunodeficiency virus (HIV) plasma viremia, proviral DNA in PBMC, viral culture, and serum HIV antibodies to negative. Discontinuation of HAART 2 years after apparent HIV eradication, however, was followed by virus replication, CD4 decline, and destruction of HIV-specific lymphocytes, epitomizing the impossibility of HIV eradication.

Low interleukin-10 production is associated with diabetes in HIV-infected patients undergoing antiviral therapy

Reduced interleukin-10 (IL-10) production is associated with type 2 diabetes in elderly individuals. Antiviral therapy (ARV)-induced immune modulation results in diminished IL-10 production, and diabetes can be observed in ARV-treated human immunodeficiency virus (HIV)-infected individuals. We analyzed, in a cross-sectional pilot study, HIV-antigen-stimulated IL-10 and tumor necrosis factor alpha (TNFalpha) production, and intracellular concentration (ICC), as well as B7-H1 expression, a marker preferentially presented by IL-10-producing cells, in 20 ARV-treated individuals in whom diabetes did (n=10; diabetes mellitus, DM) or did not (n=10; controls) develop. Pre-ARV glucose, cholesterol, and triglycerides levels, duration of HIV infection and of therapy, exposure to protease inhibitors (PI), HIV plasma viremia, CD4 counts, and nadir were similar in DM and control patients. Results showed that: (1) IL-10 production was lower; (2) IL-10 ICC was reduced; (3) B7-H1-expressing CD19(+) cells were diminished; and (4) TNFalpha production and ICC by CD4(+) T cells was augmented in DM patients. Development of diabetes in HIV infected, ARV-treated individuals could be a response to therapy. Similar to what is observed in elderly individuals, low IL-10 production is associated with diabetes in antiviral-treated HIV infection. Further studies will be necessary to clarify whether low IL-10 is a risk factor for, or a consequence of, diabetes.

Antiretroviral therapy-associated modulation of Th1 and Th2 immune responses in HIV-infected pregnant women

A successful pregnancy is characterised by an increase in Th2 cytokines and suppression of Th1 cytokine production. A Th1 to Th2 cytokine shift is also observed in the disease progression of HIV infection. Highly active antiretroviral therapy (HAART) suppresses HIV viremia, increases CD4+ cell counts and counteracts the Th1 to Th2 shift. We hypothesised that the increased risk of premature delivery reported in HIV-infected, HAART-treated pregnant women is mediated through changes in the cytokine environment in pregnancy. Here, we present results relating to levels of interleukin (IL)-2 (Th1) and IL-10 (Th2) in peripheral blood mononuclear cells (PBMCs) measured three times during pregnancy in 49 HIV-infected women. Slope values representing the trend of repeated cytokine (IL-2-PHA, IL-2-Env, IL-10-PHA and IL-10-Env) measurements within women during pregnancy were estimated and median values compared by prematurity and HAART use. Multiple regression adjusted for HAART and cytokine slope clarified the additional and independent effect of HAART on prematurity risk. Results showed favourable immunomodulation induced by HAART with increased IL-2 and decreased IL-10. HAART use and IL-10-Env slopes were not significantly associated with prematurity risk, but each unit increase in IL-2-PHA slope was associated with an 8% increased risk of premature delivery (AOR, 1.08; 95% CI, 1.0-1.17; p=0.005). HAART use in pregnancy provides significant benefits in delaying HIV disease progression and reducing the risk of mother-to-child-transmission, but may be counterproductive in terms of successful pregnancy outcome.

PIN1 promoter polymorphisms are associated with Alzheimer's disease

In our study, we analyzed the coding and promoter regions of the PIN1 gene in a group of 111 Alzheimer's disease (AD) patients looking for a possible genotype-phenotype correlation. The presence of SNPs - which could affect and modify the clinical phenotype of AD patients was also investigated. We identified two single nucleotide polymorphisms (SNPs) at positions -842 (G-->C) and -667 (C-->T) in the promoter region of the PIN1 gene. Our results evidenced a significantly higher percentage of -842C allele carriers in AD subjects with respect to healthy controls. We found that this allele significantly raised the risk of developing AD (OR 3.044, CI 1.42-6.52). The -842 and -667 SNPs were in linkage disequilibrium and combined to form haplotypes. The CC haplotype conferred a higher risk of developing AD (OR 2.95, confidence interval 1.31-6.82). Finally, protein expression analyses revealed that subjects carrying the -842 CC genotype or the CC haplotype showed reduced levels of the PIN1 protein in peripheral mononuclear cells.

Human alpha defensin in HIV-exposed but uninfected individuals

Human alpha defensins 1, 2, and 3 are produced by CD8 T cells of HIV-infected long-term nonprogressors and have an antiviral activity. alpha Defensins were examined in peripheral blood mononuclear cells (PBMCs), cervical-vaginal mononuclear cells (CVMCs), and cervical biopsies of 9 HIV-1-exposed but uninfected women (ESNs), 10 HIV-infected patients (HIV), and 13 low-risk healthy controls (HCs). Results showed that, whereas alpha defensin production and alpha defensin-expressing CD8 lymphocytes were comparable in ESNs and HIV patients, constitutive alpha defensin production by peripheral CD8 and CVMCs was augmented in ESNs compared with HCs (P = 0.001 and P = 0.058, respectively); alpha defensin mRNA was increased in PBMCs of ESNs; unstimulated, alpha defensin-expressing peripheral and mucosal CD8 lymphocytes were 10-fold higher in ESNs compared with HCs (P = 0.003 and P = 0.01, respectively); and alpha defensin mRNA and alpha defensin-expressing cells were augmented in cervical biopsies of ESN compared with HCs (mRNA:P = 0.03). The differences were reduced upon in vitro mitogen stimulation. A robust constitutive production of alpha defensin is seen in HIV-exposed uninfected individuals; these peptides could have a role in the potentially protective immune response that characterizes ESNs.

Immunization with gp120-depleted whole killed HIV immunogen and a second-generation CpG DNA elicits strong HIV-specific responses in mice

HIV-1 Immunogen is a gp120-depleted whole killed virus vaccine candidate formulated with Incomplete Freund's Adjuvant (HIV-IFA). We evaluated in a mouse model the immunogenicity of HIV-IFA by itself and when combined with HYB2055, an immunomodulatory oligonucleotide consisting of a novel DNA structure and synthetic CpR immunostimulatory motif, as an adjuvant. C57/BL6 mice were immunized with HIV-IFA alone or combined with HYB2055. Mice treated with HYB2055 or with PBS were used as controls. Compared to HIV-IFA alone, immunization with HIV-IFA and HYB2055 combination elicited strong production of HIV- and p24-specific IFNgamma, RANTES, MIP 1alpha, and MIP 1beta, as well as high titers of HIV- and p24-specific antibodies. Inclusion of HYB2055 also reduced levels of IL-5 produced by HIV-IFA alone. HYB2055 enhances the immunogenicity of HIV-IFA and shifts responses towards a type 1 cytokine profile. The immune enhancing effects of HYB2055 adjuvant were dose-dependent. These findings warrant clinical evaluation of the HIV-1 immunogen/HYB2055 candidate as a therapeutic vaccine for HIV-1 infected patients.

Programmed cell death of myelin basic protein-specific T lymphocytes is reduced in patients with acute multiple sclerosis

We investigated the apoptosis of myelin basic protein (MBP)-specific T lymphocytes in multiple sclerosis (MS) patients with acute (AMS) or stable (SMS) MS by evaluating the expression of apoptosis markers on peripheral cells. Cells of healthy controls (HC) were evaluated as well. Results showed that mitogen-stimulated apoptosis was comparable among patients and controls, whereas MBP-stimulated CD4+ and CD8+ 7-AAD+ and 7-AAD+ Fas+ cell (apoptotic cells) were significantly reduced in AMS patients. A reduction of the apoptotic rate of myelin-specific CD4+ and CD8+ T lymphocytes could be involved in the immune-mediated destruction of the myelin sheath seen in AMS patients.

Genotypes at chromosome 22q12-13 are associated with HIV-1-exposed but uninfected status in Italians

OBJECTIVE

Despite multiple and repeated exposures to HIV-1, some individuals possess no detectable HIV genome and show T-cell memory responses to the viral antigens. HIV-1-reactive mucosal IgA detected in such uninfected individuals suggests their possible immune resistance against HIV. We tested if the above HIV-1-exposed but uninfected status was associated with genetic markers other than a homozygous deletion of the CCR5 gene.

METHODS

Based on our mapping in chromosome 15 of a gene controlling the production of neutralizing antibodies in a mouse retrovirus infection, we genotyped 42 HIV-1-exposed but uninfected Italians at polymorphic loci in the syntenic segment of human chromosome 22, and compared them with 49 HIV-1-infected and 47 uninfected healthy control individuals by a closed testing procedure.

RESULTS

A significant association was found between chromosome 22q12-13 genotypes and a putative dominant locus conferring anti-HIV-1 immune responses in the exposed but uninfected individuals. Distributions of linkage disequilibrium across chromosome 22 also differed between the exposed but uninfected and two other phenotypic groups.

CONCLUSIONS

The data indicated the presence of a new genetic factor associated with the HIV-1-exposed but uninfected status.

Alpha-defensins in the prevention of HIV transmission among breastfed infants

Alpha-defensins have been observed to have anti-HIV activity but have not been investigated in relation to mother-to-child HIV transmission. We measured the concentration of alpha-defensins in breast milk of HIV-positive mothers and tested whether the concentrations were associated with HIV transmission. A nested case-control study of 32 HIV-positive women who transmitted HIV to their infants and 52 randomly selected HIV-positive women who did not transmit HIV to their infants was conducted in Lusaka, Zambia. alpha-Defensins were detected in most (79%) of the milk samples tested. Concentrations of alpha-defensins increased as breast milk HIV RNA quantity increased, and breast milk HIV RNA quantity was, in turn, a strong and significant predictor of HIV transmission. After adjustment for milk HIV RNA quantity, however, alpha-defensin concentration was significantly associated with a decreased risk of intrapartum and postnatal HIV transmission (odds ratio = 0.3, 95% confidence interval: 0.09-0.93). Our data suggest that there may be a role for alpha-defensins in prevention of HIV transmission to breastfed infants.

Distinct patterns of HIV-specific memory T lymphocytes in HIV-exposed uninfected individuals and in HIV-infected patients

BACKGROUND

Repeated exposure to HIV is not always associated with infection and multiple cohorts of HIV-exposed but seronegative individuals (ESN) have been described. HIV-specific CD4 and CD8 T lymphocytes are detected both in HIV patients and in ESN; we verified whether different patterns of HIV-specific memory T lymphocytes would be detected in individuals in whom exposure to HIV results or does not result in infection.

METHODS

Gag-specific T cells were analysed in 15 ESN, 14 HIV patients, and 15 healthy controls using extensive flow cytometry analysis.

RESULTS

Data confirmed that gag-specific T lymphocytes are present in ESN. Gag-specific T cells mainly secrete interleukin-2 in ESN and interferon-gamma in HIV patients. In addition the CD4/CD8 and the memory/naive ratios are altered, central memory (45RA-/CCR7+) CD4 and CD8 T lymphocytes are more abundant, and terminally differentiated (45RA+/CCR7- and 27-/28-) CD8 T lymphocytes are augmented in ESN individuals.

CONCLUSIONS

Exposure to HIV occurs in high risk seronegative individuals; the observation that naive cells and CM are skewed in ESN indicate that this exposure is robust enough to modulate the CM/EM ratio. The increase in late effectors and in natural killer cells seen in ESN suggests a role for these cells in preventing actual infection.

Vaccine strategies for infectious diseases

Infectious diseases are the major cause of death worldwide; in developing countries such diseases are responsible for nearly half the burden of premature death and disability. Therefore, the need for the development of new vaccine strategies aimed at preventing or limiting disease is extremely urgent. Important successes have been achieved against some infectious diseases that were once endemic or, even, epidemic (e.g., polio, smallpox, diptheria). Advances in our knowledge of the pathogenesis and immune correlates of protections are needed to develop novel vaccinal approaches to diseases such as hepatitis C, AIDS and malaria. In this review we will analyse the biological problems associated with the prevention of development and/or improvement of vaccine strategies for infectious diseases, focusing on the difficulties facing the creation of new effective vaccines for HIV infection and malaria.

Growth hormone in T-lymphocyte thymic and postthymic development: a study in HIV-infected children

OBJECTIVES

Growth hormone (GH) plays a role in thymic function, and recombinant GH may stimulate thymopoiesis in HIV-infected individuals. We performed immunologic analyses in 26 antiretroviral-treated children matched for age, pubertal status, clinical parameters, and antiretroviral exposure who did or did not show an impaired response to GH-release stimulation tests with arginine + GH-releasing hormone.

RESULTS

The following abnormalities were found in GH-deficient compared with GH-nondeficient children after >4 years of therapy: CD4 count ( P = .02) and percentage ( P = .03), CD4 as percentage of normal cells for age ( P = .003), serum interleukin-7 concentration ( P = .02), and thymic volume ( P = .01). Naive CD4 (4+62+RA+ and 4+CCR7+RA+) and CD8 (8+CCR7+RA+) lymphocytes were lower in GH-deficient children ( P = .003; P = .007; and P = .02, respectively). Postthymic pathways were also impaired in GH-deficient children. Thus, central memory (4+CCR7+RA-) CD4+ cells were reduced ( P = .006), whereas effector memory (4+CCR7-RA-) CD4+ cells ( P = .002) and late effector CD8+ lymphocytes (8+CCR7-RA+ and 8+27-28-) ( P = .009 and P = .002, respectively) were increased in these children.

CONCLUSIONS

Growth hormone plays a role in thymic and postthymic pathways, and defective GH production may be associated with incomplete immunoreconstitution. Immunomodulant agents (including GH) could be useful in patients with defective GH production.

Interleukin-10 and interleukin-6 gene polymorphisms as risk factors for Alzheimer’s disease

In the pathogenesis of Alzheimer disease (AD), it has been proposed that the anti-inflammatory interleukins such as IL-10 regulate beta-amyloid-induced microglial inflammatory responses inhibiting the proinflammatory cytokine IL-6. Since the promoters of the IL-10 and IL-6 genes show single nucleotide polymorphisms (SNPs) (IL-10: -1082 G --> A; IL-6: -174 G --> C), we investigated these SNPs and cytokine production by peripheral blood mononuclear cells in 65 AD patients and 65 controls (HC). In AD there was a significant increase of the -1082A IL-10 allele (P=0.009) and a decrease of -1082GG genotype (P=0.019). The frequency of the GG IL-6 genotype in AD was lower and the C allele significantly higher (P <0.005). The co-occurrence of IL-10 A and IL-6 C alleles significantly raised the odds ratio (OR 11.2, confidence interval: CI 1.3-97.3; P <0.05) independently of apolipoprotein E4 (adjusted OR 10.3, CI 1-108; P <0.05). Only amyloid-stimulated IL-10 production differed between the groups (P=0.023). These results raise questions regarding the inflammatory theory in AD, pointing to a pivotal role of IL-10 and IL-6 and a selective alteration in this network.

Immunomodulation induced by tucaresol in HIV infection: results of a 16 week pilot Phase I/II trial

OBJECTIVE

Immune reconstitution in highly active antiretroviral therapy (HAART)-treated individuals is incomplete and immunomodulatory compounds are needed to improve the outcome of HIV therapy. In a Phase I/II clinical trial performed on HIV-positive patients we analysed the safety and immunomodulating effects of tucaresol, a novel compound that has previously been described tn enhance cell-mediated immune responses.

PATIENTS AND METHODS

Sixteen weeks pulse dose escalation protocol. Four groups of HIV-positive patients were enrolled: group A (n=6): HAART, CD4+ 300-500 cells/microl, HIV RNA <80 copies/ml; group B (n=6): HAART-naive, CD4+ <500 cells/microl, HIV RNA >10 000 copies/ml; group C (n=3): HAART-naive, CD4+ >500 cells/microl, HIV RNA <10000 copies/ml; and group D (n=6): HAART, CD4+ <200cells/microl, HIV RNA <80 copies/ml. Tucaresol was added to HAART in group A and D patients; group B patients started tucaresol with HAART, group C patients received tucaresol alone. Clinical and immunological analyses were performed at different time points.

RESULTS

Tucaresol-related serious adverse events were observed in the first week of therapy in 2/21 patients who were viraemic when commencing treatment, but did not occur in patients on stable HAART. Tucaresol did not affect HIV viraemia whereas increases in CD4+ percentages, mainly supported by naive CD4+ cells, were observed. CD8+/28-/45RA+ cells and HIV-specific CD8+ IFNgamma- and perforin-producing cells improved whereas IL-10 mRNA diminished in tucaresol-treated patients. The effects were greater with 25 mg given every other day for 1 week.

CONCLUSION

In HAART-receiving patients with proper virus suppression, tucaresol was not associated with serious adverse events and resulted in qualitative and quantitative stimulation of HIV-specific cytotoxic T lymphocyte activity and generation of naive T cells. These data may support further exploration of tucaresol use in reconstitution of immune system parameters in HIV patients with proper virus suppression while on HAART.

Immunomodulation Induced by Tucaresol in HIV Infection: Results of a 16 Week Pilot Phase I/II Trial

Objective

Immune reconstitution in highly active anti-retroviral therapy (HAART)-treated individuals is incomplete and immunomodulatory compounds are needed to improve the outcome of HIV therapy. In a Phase I/II clinical trial performed on HIV-positive patients we analysed the safety and immunomodulating effects of tucaresol, a novel compound that has previously been described to enhance cell-mediated immune responses.

Patients and methods

Sixteen weeks pulse dose escalation protocol. Four groups of HIV-positive patients were enrolled: group A ( n=6): HAART, CD4+ 300–500 cells/μl, HIV RNA <80 copies/ml; group B ( n=6): HAART-naive, CD4+ <500 cells/μl, HIV RNA >10 000 copies/ml; group C ( n=3): HAART-naive, CD4+ >500 cells/μl, HIV RNA <10 000 copies/ml; and group D ( n=6): HAART, CD4+ <200 cells/μl, HIV RNA <80 copies/ml. Tucaresol was added to HAART in group A and D patients; group B patients started tucaresol with HAART, group C patients received tucaresol alone. Clinical and immunological analyses were performed at different time points.

Results

Tucaresol-related serious adverse events were observed in the first week of therapy in 2/21 patients who were viraemic when commencing treatment, but did not occur in patients on stable HAART. Tucaresol did not affect HIV viraemia whereas increases in CD4+ percentages, mainly supported by naive CD4+ cells, were observed. CD8+/28-/45RA+ cells and HIV-specific CD8+ IFNγ- and perforin-producing cells improved whereas IL-10 mRNA diminished in tucaresol-treated patients. The effects were greater with 25 mg given every other day for 1 week.

Conclusion

In HAART-receiving patients with proper virus suppression, tucaresol was not associated with serious adverse events and resulted in qualitative and quantitative stimulation of HIV-specific cytotoxic T lymphocyte activity and generation of naive T cells. These data may support further exploration of tucaresol use in reconstitution of immune system parameters in HIV patients with proper virus suppression while on HAART.

Granule-dependent mechanisms of lysis are defective in CD8 T cells of HIV-infected, antiretroviral therapy-treated individuals

BACKGROUND

HIV-specific cytotoxic T-cell (CTL) responses are defective in HIV-infected patients undergoing antiretroviral therapy (ART). This defect has been attributed to the decreased antigenic burden secondary to ART-associated suppression of HIV-replication, and is responsible for the rebounds of viraemia that occur when patients interrupt therapy. CTL are stimulated by type 1 cytokines and can kill targets via granule-dependent (perforin and granzymes) and -independent (tumour necrosis factor-alpha, CD95) mechanisms.

METHODS

Granule-dependent and granule-independent mechanisms of CTL killing, as well as type 1 cytokine production by CD4 T cells, were analysed in 57 chronically HIV-infected ART-treated or ART-untreated individuals.

RESULTS

The results can be summarized as follows: the frequency of gp160 (env)-specific interferon-gamma-secreting CD8 T lymphocytes correlates positively with HIV viraemia in ART-treated and -untreated patients; Env-specific perforin- and granzymes-expressing CD8 T lymphocytes, and Env-stimulated perforin and granzymes mRNA, are reduced in ART-treated patients independently of HIV viral load and of type 1 cytokine production; tumour necrosis factor-alpha production is increased in ART-treated individuals; and Env-specific immature CD8+28+27+ cells are only marginally augmented in ART-treated patients, Similar results are observed in cytomegalovirus-specific CD8 T cells and peripheral blood mononuclear cells.

CONCLUSIONS

A defect of CTL function that selectively affects the granule-dependent mechanisms of lysis is observed in ART-treated individuals. Because interferon-gamma production is higher in these patients, this could be a defect primarily involving CTL. These data suggest an independence of CD8 T-cell numbers and their lytic ability in HIV-infected, ART-receiving patients. Immunomodulants are needed to successfully treat HIV infection.

Productive infection maintains a dynamic steady state of residual viremia in human immunodeficiency virus type 1-infected persons treated with suppressive antiretroviral therapy for five years

To provide insight into the dynamics and source of residual viremia in human immunodeficiency virus (HIV) patients successfully treated with antiretroviral therapy, 14 intensely monitored patients treated with indinavir and efavirenz sustaining HIV RNA at <50 copies/ml for >5 years were studied. Abacavir was added to the regimen of eight patients at year 5. After the first 9 months of therapy, HIV RNA levels had reached a plateau ("residual viremia") that persisted for over 5 years. Levels of residual viremia differed among patients and ranged from 3.2 to 23 HIV RNA copies/ml. Baseline HIV DNA was the only significant pretreatment predictor of residual viremia in regression models including baseline HIV RNA, CD4 count, and patient age. In the four of five patients with detectable viremia who added abacavir to their regimen after 5 years, HIV RNA levels declined rapidly. The estimated half-life of infected cells was 6.7 days. Decrease in activated memory cells and a reduction in gamma interferon production to HIV Gag and p24 antigen in ELISpot assays were observed, consistent with a decrease in HIV replication. Thus, in patients treated with efavirenz plus indinavir, levels of residual viremia were established by 9 months, were predicted by baseline proviral DNA, and remained constant for 5 years. Even after years of highly suppressive therapy, HIV RNA levels declined rapidly after the addition of abacavir, suggesting that productive infection contributes to residual ongoing viremia and can be inhibited with therapy intensification.

Mucosal immune response to Human Papilloma Virus (HPV) infection in HIV positive women

Mucosal immunity plays a central role in the control of genital human papilloma virus (HPV) infection. HIV infection is associated with higher risks of HPV-induced neoplasias. Prevalence, incidence and evolution of genital HPV lesions are correlated with the level of immunodepression. Several changes of the local immune response in the genital tract of HIV infected women have been demonstrated. The influence of HIV on the production of some immunoregulatory cytokines appears of particular interest. The shift from the helper T cells type 1 (Th1) to the helper T cells type 2 (Th2) immune response, which determines the downregulation of the cell-mediated immunity, may explain the frequent loss of immunologic control of HPV and its oncological complications

Assessment of immune reconstitution to Pneumocystis carinii in HIV-1 patients under different highly active antiretroviral therapy regimens

The introduction of protease inhibitors (PIs) gave a dramatic drop in AIDS-related opportunistic events, mainly due to induced immune reconstitution. Discontinuation of prophylaxis against Pneumocystis carinii is considered safe when CD4 > 200 cells/mm(3). Ideally, we should have specific functional tests for HIV-1-related decisions. We examined viro-immunological profiles, clinical outcome and lymphocyte proliferation (LP) to P. carinii and other antigens in 108 subjects: 28 AIDS presenters with P. carinii pneumonia (PCP) (CD4 < 200 cells/mm(3)), 22 untreated asymptomatic HIV-1-infected patients (CD4 > 200 cells/mm(3)), 44 HIV-1-infected patients immune-reconstituted on antiretroviral regimens and 14 HIV-1-uninfected healthy controls. As regards viral load, there was no significant difference in therapy duration, nadir, or actual CD4, CD8, natural killer or B cell counts in immune-reconstituted patients receiving protease inhibitor (PI)-based versus those receiving PI-sparing antiretroviral regimens. Among subjects showing abnormally low P. carinii-specific LP, three patients receiving a non-nucleoside reverse transcriptase inhibitor (nNRTI) developed PCP despite having CD4 > 250 cells/mm(3). P. carinii-specific LP could be considered for doubtful situations, i.e. for a safer clinical decision of discontinuing or restarting prophylaxis in patients with a low CD4 nadir or experiencing a sudden CD4 decrease under highly active antiretroviral therapy (HAART). HIV-1 PIs, having in vitro aspecific effects against Pneumocystis, could play a clinically significant anti-opportunistic role, thus offering a further benefit in heavily immunosuppressed patients during early stages of antiretroviral therapy.

IL-4 and CXCR4 upregulation in HIV-infected and uninfected individuals from Maharashtra-Mumbai

We extended the investigation of the virus-host interaction in developing countries by analysing Indian HIV-infected and uninfected individuals from Maharashtra-Mumbai. Results showed that CXCR4 messenger RNA and surface expression, as well as IL-4 mRNA and T allele frequency at the -589 site in the IL-4 gene (high IL-4 production) were significantly increased in Indian compared with Italian individuals. Because IL-4 stimulates CXCR4 expression this observation could be explained by the higher frequency of the -589T IL-4 polymorphism.

Research on psychoimmunology

Several lines of evidence suggest a role for the immune system in the multifactorial pathogenesis of schizophrenia and other psychiatric and neurodegenerative disease. Later, the role of immune mediators like cytokines became a source of main interest related to the process on inflammation in the CSM. In this article we report the results of our research on cytokines in a different groups of psychiatric patients following their clinical symptomatology and the course of diseases. In particular, we observed a prevalent type 1 cytokine profile in acute multiple sclerosis patients, while IL-10 production predominated in stable multiple sclerosis individuals. The modifications of cytokine profiles observed in schizophrenic patients suggests that clinical improvement is associated with a reduction in the inflammatory-like situation present in those not currently under treatment. Our data on Alzheimer's disease (AD) support the role of the inflammatory process in the pathogenesis of AD and reinforce the hypothesis that the neurodegenerative processes in the AD patients are associated with an abnormal antigen-specific immune response. The activation of immune system mechanisms observed in obsessive compulsive disorders could be due to the combination of endogenous (hormonal alterations associated to the modifications in the hypothalamic-pituitary-adrenal axis) and exogenous (viral or bacterial infections) factors.

Distinct immune profiles characterize patients with diffuse or limited systemic sclerosis

Mitogen-stimulated IL-2, IFN-gamma, TNF-alpha (type 1 cytokines), and IL-10 (type 2 cytokine) production by peripheral blood mononuclear cells, as well as expression of surface markers on immune cells, was evaluated in systemic sclerosis (SSc) patients. Fifty-four SSc patients with either diffuse (dSSc) or limited (lSSc) disease and 20 age- and sex-matched healthy controls (HCs) were examined. Fourteen patients were treated with prednisone and 9 patients with prednisone and cyclophosphamide pulses. Results showed that (1) IL-2 production is significantly decreased, whereas IL-10 is higher in untreated patients compared to HCs; IL-10, IFN-gamma, and TNF-alpha production is higher in lSSc compared to dSSc patients; (2) CD4+25+ (IL-2R), CD8+, and CD8+45RA-28+57- (memory) lymphocytes are reduced in patients compared to HCs; (3) CD95-expressing CD4+ and CD8+ cells are significantly higher in dSSc patients; and (4) steroids are more effective alone than in combination with cyclophosphamide in reducing IL-10 and IFN-gamma production in these patients. These results confirm that a complex imbalance in cytokine production is present in SSc patients and suggest that peculiar phenotypic populations are underrepresented in these patients. Overexpression of Fas in dSSc could results from the attempt of the immune system to induce apoptosis of autoreactive T-cell clones.

Cytokine production in women with antiretroviral treatment-associated breast fat accumulation and limb wasting

OBJECTIVE

To test the cytokine production of peripheral blood mononuclear cells in a group of HIV-infected women with breast enlargement and lower limb wasting while receiving antiretroviral therapy (ART) including a protease inhibitor.

DESIGN

Case-control study including 20 women with fat tissue alterations and 20 matched controls treated with comparable ART.

METHODS

Adipose tissue alterations (ATA) were defined by increased breast size (> or = 2 bra sizes) accompanied by lower limb fat wasting. A randomly selected subset of patients underwent analyses including: dual energy X-ray absorptiometry, metabolic and endocrine assays, in vitro cytokine production testing [interferon-gamma, interleukin (IL)-2, IL-4, IL-10, IL-12, tumor necrosis factor-alpha (TNF-alpha)] after appropriate stimulation; T-cell phenotyping, T-helper function after stimulation with either tetanus toxoid, influenza antigen, allogeneic peripheral blood lymphocytes, and phytohemagglutinin. Endocrinological study included the determination of plasma concentrations of prolactin, growth hormone, testosterone, adrenocorticotropic hormone, cortisol and C-peptide.

RESULTS

In vitro production of IL-12 was higher (P = 0.0001), and TNF-alpha (P = 0.0093) and IL-10 (P < 0.0001) production were lower in stimulated peripheral blood mononuclear cells of ATA-positive women compared with ATA-negative women. ATA-positive women also showed a better response to tetanus toxoid (P = 0.021) and a lower median fluorescence intensity of CD14/DR (P=0.033). Plasma C-peptide values were higher in ATA-positive women compared with ATA-negative women (P = 0.033), even if in the normal range (< 4 ng/ml) in all but one of the ATA-positive patients.

CONCLUSION

HIV-1-infected women who developed breast enlargement and lower limb fat wasting while receiving ART had a favorable immunological profile with efficient IL-12 production and T-helper function, and with TNF-a production in the range of a HIV-negative reference population. These findings suggest that the rescue of some immune functions under ART may be involved in the pathogenesis of this particular adipose tissue disorder.

B7-H1 is up-regulated in HIV infection and is a novel surrogate marker of disease progression

The ligation of programmed death-ligand 1 (B7-H1) to T cells results in the preferential production of interleukin 10 (IL-10). We investigated if B7-H1 would be up-regulated in HIV infection, a disease characterized by increased IL-10 production, by measuring B7-H1, B7-1 (CD80), and B7-2 (CD86) expression and mRNA in 36 HIV-infected patients and in 22 healthy controls (HCs). Results showed that (1) B7-H1 expression and mRNA are augmented in cells of HIV patients; (2) increased IL-10 production in these patients is largely induced by B7-H1-expressing CD14(+) cells; (3) an inverse correlation is detected between B7-H1 expression and CD4 counts, whereas the up-regulation of B7-H1 is directly associated with HIV plasma viremia; (4) antiviral therapy results in the parallel down modulation of IL-10 production and B7-H1 expression/synthesis; and (5) B7-H1/CD80 and B7-H1/CD86 mRNA ratios are increased in peripheral blood mononuclear cells (PBMCs) of HIV patients compared with HCs. B7-H1 synthesis and expression are up-regulated in HIV infection, and the degree of dysregulation correlates with the severity of disease. Aberrant antigen presentation by antigen-presenting cells (APCs) that exhibit increased B7-H1 expression and IL-10 production in HIV infection could be responsible for T-lymphocyte unresponsiveness and loss of protective immunity. B7-H1 is a surrogate marker potentially involved in AIDS disease progression.

Mucosal and systemic HIV-1-specific immunity in HIV-1-exposed but uninfected heterosexual men

BACKGROUND

Despite multiple, repeated exposures to HIV-1, some individuals never seroconvert. Mucosal and systemic immune correlates of this condition have been analysed in HIV-1-exposed women but no data are available concerning mucosal immunity and HIV-1-specific immune responses in exposed but uninfected men.

DESIGN

We analysed cellular and humoral immune parameters in peripheral lymphocytes, seminal fluid and urethral swabs of 14 recently HIV-1-exposed seonegative (ESN) heterosexual men, seven HIV-seropositive patients and seven healthy controls.

RESULTS

HIV-1-specific IgA were detected in urethral swabs of 11 out of 14 ESN and of six out of seven HIV-seropositive patients; Env- and Gag-specific IFNgamma-producing CD4 and CD8 peripheral lymphocytes were present in ESN and HIV-seropositive patients; seminal lymphocytes, but not peripheral blood lymphocytes, of ESN were enriched in activated populations (CD8CD38RO and CD4CD25). p24-specific cytotoxic T lymphocytes were correlated with the percentage of CD4 in the HIV-seropositive partners. High urethral concentrations of HIV-1-specific IgA were seen in those ESN with the most recent unprotected sexual episode.

CONCLUSIONS

This is the first report of HIV-specific mucosal immunity in ESN men. These data add to the body of knowledge of the immune correlates present in exposed, uninfected individuals and might be important in vaccine design.

Detection of mucosal antibodies in HIV type 1-infected individuals

HIV-1-specific mucosal IgA antibodies may correlate with protection in highly exposed but uninfected individuals, but have been detected at highly variable levels in HIV-1-infected individuals. To determine the best assays for detection of IgA antibodies in mucosal samples, rectal washes from 16 HIV-1-infected and 14 uninfected individuals were distributed to six laboratories experienced in detection of mucosal antibodies. Assays for HIV-1-specific IgA and IgG were performed in a blinded fashion by each of the laboratories using modifications of ELISA and chemiluminescence-enhanced Western blotting. Rectal washes contained easily detectable total IgA levels that did not differ between HIV-1-infected and uninfected groups. Irrespective of the assay used, HIV-1-specific IgA antibodies were absent in most samples; only one laboratory identified a higher frequency of positive samples from HIV-1-infected than uninfected individuals. In spite of 10-fold lower levels of total IgG than IgA, all but one laboratory identified HIV-1-specific IgG in most rectal washes of HIV-1-infected individuals. Comparable and readily detectable levels of influenza-specific IgA antibodies were present in nasal, salivary, and rectal secretions from both HIV-1-infected and uninfected individuals. These observations suggest a selective alteration in the production of HIV-1-specific IgA antibodies in HIV-1-infected individuals.

Contemporary antithrombotic strategies in patients undergoing coronary stent implantation

The number of annual stenting procedures has been increasing at a rapid pace since coronary stents were first used in clinical practice just over a decade ago. Subacute stent thrombosis, which usually has serious clinical consequences, plagued the stent early experience despite intense anticoagulation therapy. The reduction of stent thrombosis was among the factors that contributed to stent growth and widespread acceptance in recent years. This was the result of improved implantation techniques, advances in adjunctive pharmacotherapy and evolution in stent designs, delivery systems and non-thrombogenic coatings. However, novel designs and materials customized for particular lesion types and newer anti-restenotic treatments could influence stent thrombogenicity. Intravascular brachytherapy and drug-eluting stents have been shown to reduce the incidence of in-stent restenosis preventing cellular proliferation. However, by interfering with the re-endothelization process they may also increase the risk of stent thrombosis. To prevent a recrudescence of this feared complication, future research direction must focus on the hemocompatibility aspects of new technologies, along with further refinement of stent-deployment techniques and antithrombotic strategies.

Early and late effects of highly active antiretroviral therapy: a 2 year follow-up of antiviral-treated and antiviral-naive chronically HIV-infected patients

BACKGROUND

Control of HIV replication can be observed in highly active antiretroviral therapy (HAART)-treated and, occasionally, in HAART-naive patients. The immunological correlates of these situations were examined in a longitudinal study.

DESIGN

A prospective study. Immunovirological analyses in 16 chronically HIV-infected, HAART-naive patients (time 0) who started HAART. Fifteen patients (short-term HAART) were re-evaluated after 24 months (time 1). Results were compared with those of 30 patients who received HAART for more than 12 months before the study period (long-term HAART) and were analysed at the same timepoints. Fifteen patients who were antiviral therapy naive (naive) at both timepoints were also studied.

RESULTS

Over a 24-month period CD4 and CD8 cell counts and viraemia remained unchanged in naive and long-term HAART patients; CD4 cell counts increased and viraemia diminished in short-term HAART individuals. Antigen-stimulated proliferation was unmodified in naive and short-term HAART patients, but improved in long-term HAART individuals. Gp160-stimulated IL-2 and IFN-gamma production was augmented in long-term HAART patients and marginally modified in other patients. IL-7 production was unmodified in naive individuals, augmented in short-term HAART patients, and diminished in long-term HAART patients. Chemokine production was similar in all patients. Naive patients showed the highest CD8 cell counts at both timepoints.

CONCLUSION

HAART has a major impact on the outcome of HIV infection, even if functional immune modulation in HAART-treated patients is evident only after long periods of therapy. Low but detectable HIV replication in HAART-naive patients with preserved immune functions might not be associated with CD4 cell reduction, functional immune defects, or changes in viraemia.