Nef-specific CD45RA+ CD8+ T cells secreting MIP-1β but not IFN-γ are associated with nonprogressive HIV-1 infection

Background

Long-term survival of HIV-1 infected individuals is usually achieved by continuous administration of combination antiretroviral therapy (ART). An exception to this scenario is represented by HIV-1 infected nonprogressors (NP) which maintain relatively high circulating CD4+ T cells without clinical symptoms for several years in the absence of ART. Several lines of evidence indicate an important role of the T-cell response in the modulation of HIV-1 infection during the acute and chronic phase of the disease.

Results

We analyzed the functional and the differentiation phenotype of Nef- and Tat-specific CD8+ T cells in a cohort of HIV-1 infected NP in comparison to progressors, ART-treated seropositive individuals and individuals undergoing a single cycle of ART interruption. We observed that a distinctive feature of NP is the presence of Nef-specific CD45RA+ CD8+ T cells secreting MIP-1beta but not IFN-gamma. This population was present in 7 out of 11 NP. CD45RA+ IFN-gamma^neg MIP-1beta+ CD8+ T cells were not detected in HIV-1 infected individuals under ART or withdrawing from ART and experiencing a rebounding viral replication. In addition, we detected Nef-specific CD45RA+ IFN-gamma^neg MIP-1beta+ CD8+ T cells in only 1 out of 10 HIV-1 infected individuals with untreated progressive disease.

Conclusion

The novel antigen-specific CD45RA+ IFN-gamma^neg MIP-1beta+ CD8+ T cell population represents a new candidate marker of long-term natural control of HIV-1 disease progression and a relevant functional T-cell subset in the evaluation of the immune responses induced by candidate HIV-1 vaccines.     

Efficient monitoring of HIV-1 vertically infected children in Kenya on first-line antiretroviral therapy

Background

Worldwide access to antiretroviral therapy (ART) in low- and middle-income countries has significantly increased. Although this presents better treatment options for HIV-infected individuals, the challenge of monitoring ART in these settings still remains.

Objective

To investigate efficient and cost-effective criteria for assessing ART failure among HIV-1-infected children on first-line ART in resource-limited settings.

Study design

Retrospective analysis of 75 HIV-1 vertically infected Kenyan children with a follow-up period of 24 months after initiating ART. Plasma viral load, peripheral CD4⁺T-cell counts and HIV-1 drug-resistance mutations were monitored biannually.

Results

Plasma viral load (VL) was suppressed to undetectable level or more than 1.5 log₁₀ from baseline levels in 53 (70.7%) children within 24 months. VL in the remaining 22 (29.3%) children was not suppressed significantly. Of the 22 children, 21 were infected with HIV-1 strains that developed drug-resistance mutations; 9 within 12 months and 12 between 12 and 24 months. Among the 53 who were successfully treated, VL was suppressed in 33 within 12 months and in 20 between 12 and 24 months. There was no significant difference in VL at baseline and the change of CD4⁺T-cell counts after initiating ART between those treated successfully and the failure groups.

Conclusion

After initiating ART, children may require longer times to achieve complete viral suppression. Plasma viral load testing 24 months after initiating ART could be used to differentiate ART failures among HIV-1 vertically infected children in resource-limited settings. Additionally, drug resistance testing, if affordable, would be helpful in identifying those failing therapy and in choosing second-line regimens.     

Affordable flow cytometry for enumeration of absolute CD4+ T-lymphocytes to identify subtype C HIV-1 infected adults requiring antiretroviral therapy (ART) and monitoring response to ART in a resource-limited setting

Background  

The World Health Organization (WHO)'s "3 × 5 program" has spurred efforts to place 3 million people on combination antiretroviral therapy (ART) for treatment of AIDS in resource-limited countries. Paradoxically, the cost of CD4⁺ T-lymphocyte count essential for decision-making to commence HIV positive adults on ART as well as for monitoring responses to ART remains unaffordable in most resource-limited countries. Thus, low-cost methods for enumerating CD4⁺ T-lymphocyte are urgently needed.     

T cell Activation does not drive CD4 decline in longitudinally followed HIV-infected Elite Controllers

Background

Elite controllers (EC) are a rare subset of HIV infected individuals who control viral load below 50 copies/ml of plasma without treatment.

Methods

Thirty four EC were studied. The slope of CD4 count change was available for 25 of these subjects. We assessed immune activation by measuring the percent of CD38⁺HLA-DR⁺CD8⁺ T cells in the EC group and comparing it with that in 24 treatment-naïve HIV disease progressors and 13 HIV uninfected healthy controls.

Results

Compared to HIV uninfected subjects, EC had higher percentages of CD38⁺HLA-DR⁺CD8⁺ T cells (p < 0.001) that was lower than that observed in progressors (p < 0.01). Fifteen of 25 EC had a slope of CD4 count change that was not significantly different from 0 while 3 had a positive and 7 a negative CD4 count slope. Immune activation did not distinguish EC subsets with stable/increasing versus declining CD4 counts.

Conclusions

Elevated immune activation in ECs is not associated with a faster rate of CD4 decline     

B-Cell and T-Cell Phenotypes in CVID Patients Correlate with the Clinical Phenotype of the Disease

Background

Common variable immunodeficiency (CVID) is a heterogeneous disorder characterized by recurrent infections and defective immunoglobulin production.

Methods

The DEFI French national prospective study investigated peripheral T-cell and B-cell compartments in 313 CVID patients grouped according to their clinical phenotype, using flow cytometry.

Results

In patients developing infection only (IO), the main B-cell or T-cell abnormalities were a defect in switched memory B cells and a decrease in naive CD4⁺ T cells associated with an increase in CD4⁺CD95⁺ cells. These abnormalities were more pronounced in patients developing lymphoproliferation (LP), autoimmune cytopenia (AC), or chronic enteropathy (CE). Moreover, LP and AC patients presented an increase in CD21^low B cells and CD4⁺HLA-DR⁺ T cells and a decrease in regulatory T cells.

Conclusion

In these large series of CVID patients, the major abnormalities of the B-cell and T-cell compartments, although a hallmark of CVID, were only observed in half of the IO patients and were more frequent and severe in patients with additional lymphoproliferative, autoimmune, and digestive complications.     

Cocaine Enhances HIV-1–Induced CD4+ T-Cell Apoptosis: Implications in Disease Progression in Cocaine-Abusing HIV-1 Patients

Substance abuse is a major barrier in eradication of the HIV epidemic because it serves as a powerful cofactor for viral transmission, disease progression, and AIDS-related mortality. Cocaine, one of the commonly abused drugs among HIV-1 patients, has been suggested to accelerate HIV disease progression. However, the underlying mechanism remains largely unknown. Therefore, we tested whether cocaine augments HIV-1–associated CD4⁺ T-cell decline, a predictor of HIV disease progression. We examined apoptosis of resting CD4⁺ T cells from HIV-1–negative and HIV-1–positive donors in our study, because decline of uninfected cells plays a major role in HIV-1 disease progression. Treatment of resting CD4⁺ T cells with cocaine (up to 100 μmol/L concentrations) did not induce apoptosis, but 200 to 1000 μmol/L cocaine induced apoptosis in a dose-dependent manner. Notably, treatment of CD4⁺ T cells isolated from healthy donors with both HIV-1 virions and cocaine significantly increased apoptosis compared with the apoptosis induced by cocaine or virions alone. Most important, our biochemical data suggest that cocaine induces CD4⁺ T-cell apoptosis by increasing intracellular reactive oxygen species levels and inducing mitochondrial depolarization. Collectively, our results provide evidence of a synergy between cocaine and HIV-1 on CD4⁺ T-cell apoptosis that may, in part, explain the accelerated disease observed in HIV-1–infected drug abusers.The HIV/AIDS pandemic has claimed the lives of an estimated 35 million people (http://www.who.int/mediacentre/factsheets/fs360/en/index.html, last updated October 2013). Although anti-retroviral therapy (ART) has dramatically reduced HIV/AIDS-related mortality,¹ substance use is a major barrier for combating the HIV/AIDS pandemic because it is associated with transmission, delayed diagnosis, delayed initiation of therapy, and poor adherence to therapy.² Cocaine is a commonly abused drug among HIV-1 patients,^3–5 and studies suggest that cocaine abuse may accelerate HIV-1 disease progression. For example, Vittinghoff et al⁶ documented an increased risk of HIV-1 disease progression among frequent cocaine users. Arnsten et al^7,8 have reported that active cocaine use strongly predicts failure to viral suppression. Similarly, Webber et al⁹ suggested that use of cocaine, along with alcohol, might accelerate HIV-1 disease progression. In addition, Lucas and colleagues^10–12 found that cocaine users have inferior virological and immunological responses to ART. The effects of cocaine on disease progression in these studies can be attributed, in part, to nonadherence to ART, because substance use is often associated with reduced adherence and/or access to ART.¹³ There are also reports that did not find significant association between cocaine abuse and HIV-1 disease progression.^14,15 However, Baum et al³ found that cocaine users have higher viral load and were twice as likely to progress to AIDS when controlled for ART use. Notably, Palepu et al¹⁶ reported that HIV-1–positive drug users, while taking ART, were less likely to suppress the viral load. Recently, Rasbach et al¹⁷ have suggested that active cocaine use among HIV-1 patients is associated with lack of virological suppression, independent of ART adherence. Although in vitro studies suggest that increased HIV-1 replication by cocaine^18–21 may play a role, the mechanism by which cocaine accelerates HIV-1 disease progression remains unclear. Therefore, we evaluated whether cocaine could potentiate HIV-1–induced CD4⁺ T-cell apoptosis because CD4⁺ T-cell decline is an important predictor of HIV-1 disease progression. Our data suggest a synergy between cocaine and HIV-1 on CD4⁺ T-cell apoptosis and highlight the molecular interplay between cocaine abuse and HIV-1 disease progression.     

Varied sensitivity to therapy of HIV-1 strains in CD4<Superscript>+</Superscript> lymphocyte sub-populations upon ART initiation

Background

Although antiretroviral therapy (ART) has proven its success against HIV-1, the long lifespan of infected cells and viral latency prevent eradication. In this study we analyzed the sensitivity to ART of HIV-1 strains in naïve, central memory and effector memory CD4⁺ lymphocyte subsets.

Methods

From five patients cellular HIV-1 infection levels were quantified before and after initiation of therapy (2-5 weeks). Through sequencing the C2V3 region of the HIV-1 gp120 envelope, we studied the effect of short-term therapy on virus variants derived from naïve, central memory and effector memory CD4⁺ lymphocyte subsets.

Results

During short-term ART, HIV-1 infection levels declined in all lymphocyte subsets but not as much as RNA levels in serum. Virus diversity in the naïve and central memory lymphocyte populations remained unchanged, whilst diversity decreased in serum and the effector memory lymphocytes. ART differentially affected the virus populations co-circulating in one individual harboring a dual HIV-1 infection. Changes in V3 charge were found in all individuals after ART initiation with increases within the effector memory subset and decreases found in the naïve cell population.

Conclusions

During early ART virus diversity is affected mainly in the serum and effector memory cell compartments. Differential alterations in V3 charge were observed between effector memory and naïve populations. While certain cell populations can be targeted preferentially during early ART, some virus strains demonstrate varied sensitivity to therapy, as shown from studying two strains within a dual HIV-1 infected individual.

     

CD4 T cell nadir independently predicts the magnitude of the HIV reservoir after prolonged suppressive antiretroviral therapy

Background

The level of HIV-1 integrated DNA in CD4 T cells was reported to predict the evolution of untreated HIV-1 infection independently of CD4 cell counts or plasma HIV-1 RNA levels. However, the relevance of reservoir level while on efficient antiretroviral therapy (ART) is still unknown.

Objectives

To evaluate factors that may contribute to the establishment and maintenance of HIV-1 reservoir size in ART-treated HIV-1-infected adults with complete suppression of viremia.

Study design

35 subjects receiving ART with plasma HIV-1 RNA below the limit of detection for an average duration of 3.2 years were studied. A highly sensitive PCR was used to assess HIV-1 integrated DNA levels in sorted CD4 T cells.

Results

The mean HIV-1 integrated DNA was 300 ± 7 copies/10⁶ CD4 cells (range 10-1408). In univariate analysis, the levels of HIV-1 proviral DNA appeared to be independent of duration of HIV-1-infection, duration on ART, time since HIV-1 viral load was undetectable, delay between HIV-1 infection and starting ART, or viral load before starting ART. Conversely, CD4 T cell nadir, CD4/CD8 ratio and, to lesser degree, CD4 T cell counts were inversely associated with HIV-1 proviral DNA levels. In multivariate analysis, only CD4 T cell nadir significantly predicted levels of HIV-1 proviral DNA (P = 0.025).

Conclusions

CD4 T cell nadir strongly predicted reservoir size independently of other factors in HIV-1-infected adults with complete suppression of viremia. Collectively, these results indicate that the extent of CD4 T cell depletion before ART drives the size of the viral reservoir after prolonged therapy.     

Increased T-Cell Activation and Th1 Cytokine Concentrations Prior to the Diagnosis of B-Cell Lymphoma in HIV Infected Patients

Background

Despite the use of combined antiretroviral therapy, HIV-infected individuals have a higher risk of developing B-cell lymphoma compared to the general population. We aim to explore whether lymphocyte activation, increase in Th1 response as well as markers of EBV reactivation, may precede lymphoma diagnosis.

Methods

Thirteen cases and 26 controls matched on CD4⁺ T-cell count and HIV plasma viral load were identified. Samples were collected 0 to 5 years prior to B-cell lymphoma diagnosis. Seven out of 13 (54 %) and 16/26 (61.5 %) of cases and controls were receiving antiretroviral therapy at the time of sampling, respectively. CD8⁺ T-cell activation and Th1 cytokine concentrations were measured before lymphoma onset, together with IgG antibodies directed against viral capsid antigen (VCA) and serum levels of EBV DNA.

Results

A higher level of CD8⁺ T-cell activation was observed in patients developing lymphoma. Four out of seven Th1 cytokine serum concentrations were significantly higher in patients with lymphoma than in the control group: IL-2R, IL-12p40/70, IFN-γ-inducible protein 10 (IP-10) and monokine induced by IFN-γ (MIG). Anti-VCA IgG level were significantly higher in cases than in controls. Four cases (30 %) but no controls had detectable EBV DNA in serum.

Conclusion

A higher level of T-cell activation, Th1 cytokine serum concentration and markers of EBV replication, preceded B-cell lymphoma diagnosis. This may suggest that viral antigen stimulation is associated with the genesis of lymphoma in HIV-infected patients.     

Combined use of etanercept and MTX restores CD4+/CD8+ ratio and Tregs in spleen and thymus in collagen-induced arthritis

Objective

To further explore the mechanism of etanercept (ENT, rhTNFR:Fc) and methotrexate (MTX) in the combined treatment of rheumatoid arthritis (RA), we investigated whether thymic and splenic T-cell subsets and their related cytokines imbalance could be restored by ETN/MTX treatment.

Methods

The effect of ETN/MTX on collagen-induced arthritis (CIA) was evaluated by arthritis scores, joint and spleen histopathology, as well as indices of thymus and spleen. T lymphocytes proliferation was determined by [³H]-TdR incorporation. Levels of TNF-α, LT-α, IL-1β, RANKL, IL-10, IL-17, IFN-γ and IL-6 were detected by enzyme linked immunosorbent assay. The subsets of T lymphocytes including CD4⁺, CD8⁺, CD3⁺CD4⁺, CD4⁺CD25⁺, CD4⁺CD62L⁺ and CD4⁺CD25⁺Foxp3⁺ cells were quantified using flow cytometry.

Results

Combined administration of ETN/MTX significantly inhibited the proliferation of T lymphocytes, decreased serum IL-6, TNF-α, IL-1β, RANKL and macrophage supernatant IL-17, LT-α, increased serum IFN-γ and macrophage supernatant IL-10. Moreover, the combined administration could restore CD4⁺/CD8⁺ ratio and Treg cells of CIA thymus and spleen.

Conclusion

Taken together, our findings suggest that ENT/MTX may modify the abnormal T lymphocytes balance from central to peripheral lymphoid organs, which may partially, explained the mechanism of the combined administration.     

Cytotoxic HIV-1 p55gag-specific CD4+ T cells produce HIV-inhibitory cytokines and chemokines

CD4⁺ T-helper cells appear to be essential in sustaining immune responses in chronic viral infections, as the maintenance of CD8⁺ cytotoxic T-lymphocyte responses and the control of viremia were demonstrated to depend on CD4⁺ T cell help. In order to investigate the function of HIV-specific CD4⁺ T cells in chronic HIV-1-infection, 49 chronically HIV-infected patients were analyzed before and 3 and 6 months after initiation of antiviral treatment. Ten patients showed a substantial, although weak, proliferative response to HIV-1-p55^gag protein for which no improvement was observed upon initiation of HAART. From one individual, HIV-1-p55^gag-specific CD4-positive T-cell clones were generated that were heterogeneous in their TCR V gene usage and HLA-DRB1*13 and DRB1*03 restricted, respectively. In addition, some CD4⁺ TCC produced substantial amounts of IFN- and MIP-1/, were perforin-positive, and showed cytotoxic activity. These diverse functional features of HIV-specific CD4⁺ T cells suggest that they may exert direct antiviral activity.     

Role of immune activation in CD4<Superscript>+</Superscript> T-cell depletion in HIV-1 infected Indian patients

Objectives

The correlation of immune activation with CD4⁺ depletion and HIV-1 disease progression has been evidenced by several studies involving mainly clade B virus. However, this needs to be investigated in developing countries such as India predominately infected with clade C virus.

Materials and methods

In a cross-sectional study of 68 antiretroviral treatment naïve, HIV-1 infected Indian patients, we studied the association between CD4⁺ T cells, plasma HIV-1 RNA levels, and immune activation markers using unadjusted and adjusted correlative analyses.

Results

Significant negative correlations of higher magnitude were observed between the CD4⁺ T cell percentages and plasma HIV-1 RNA levels in the study population when adjusted for the effects of immune activation markers. However, the negative association of CD4⁺ T cells with immune activation markers remained unaffected when controlled for the effects of plasma HIV-1 RNA levels.

Conclusions

Our results support the important role of immune activation in CD4⁺ T cell depletion and disease progression during untreated HIV-1 infection.

     

The DC-SIGNR 7/5 Genotype is Associated with High Dendritic Cell Counts and Their Subsets in Patients Infected with HIV-1

Purpose

The aim of this study was to assess peripheral blood dendritic cell (DC) frequencies and Dendritic Cell-specific intracellular adhesion molecule 3 grabbing non-integrin related (DC-SIGNR) genotyping in healthy individuals, injecting drug users and HIV-1 infected individuals and correlate with different clinical parameters from north India.

Methods

Blood from 30 seronegative healthy individuals, 30 injecting drug users, and 30 patients infected with HIV-1 from North India were collected. Peripheral blood DC frequencies were determined by flow cytometry and repeat region polymorphism in DC-SIGNR was performed by PCR.

Results

There was a significantly lower number of DCs and their subsets in patients infected with HIV-1 compared to injecting drug users and healthy individuals. A significant positive correlation of DCs and their subsets with CD4⁺ T cells and negative correlation with HIV-1 viral load was found. A salient finding of this study was the association of the heterozygous 7/5 DC-SIGNR genotypes with higher percentage of DCs and their subsets and higher CD4⁺ T cell counts and lower viral load compared to the homozygous 7/7 DC-SIGNR genotypes in patients infected with HIV-1.

Conclusions

This is the first study to assess the DC subsets and its association with DC-SIGNR polymorphism in injecting drug users and HIV-1 infected patients and suggests the protective role of 7/5 DC-SIGNR genotypes in HIV-1 infection.     

SV-IV Peptide1–16 reduces coagulant power in normal Factor V and Factor V Leiden

Background

Alefacept (anti-CD2) biological therapy selectively targets effector memory T cells (Tem) in psoriasis vulgaris, a model Type 1 autoimmune disease.

Methods

Circulating leukocytes were phenotyped in patients receiving alefacept for moderate to severe psoriasis.

Results

In all patients, this treatment caused a preferential decrease in effector memory T cells (CCR7^- CD45RA^-) (mean 63% reduction) for both CD4⁺ and CD8⁺ Tem, while central memory T cells (Tcm) (CCR7⁺CD45RA^-) were less affected, and naïve T cells (CCR7⁺CD45RA⁺) were relatively spared. Circulating CD8⁺ effector T cells and Type 1 T cells (IFN-γ-producing) were also significantly reduced.

Conclusion

Alefacept causes a selective reduction in circulating effector memory T cells (Tem) and relative preservation of central memory T cells (Tcm) in psoriasis.     

Tuberculosis associated immune reconstitution inflammatory syndrome in patients infected with HIV: meningitis a potentially life threatening manifestation

Background

Tuberculosis (TB) is the most common co infection in HIV-infected persons in India, requiring concomitant administration of anti TB and antiretroviral therapies. Paradoxical worsening of tuberculosis after anti-retroviral therapy (ART) initiation is frequently seen.

Objective

To study the frequency, clinical presentation and outcome of paradoxical tuberculosis associated immune reconstitution inflammatory syndrome (TB-IRIS) in HIV infected patients in a TB hospital in North India.

Design

A retrospective chart review of HIV-infected TB patients on anti-tubercular treatment (ATT) at time of ART initiation over a 3?year period. Medical records were reviewed for clinical manifestations and outcome in patients who developed TB-IRIS.

Results

514 HIV-infected patients were enrolled between January 2006 and December 2008. Thirteen (12.6%) of 103 patients who had received ART and ATT simultaneously developed paradoxical TB-IRIS. Clinical presentations of paradoxical TB-IRIS included new lymphadenopathy (n?=?3), increase in size of existing lymphadenopathy (n?=?3), worsening of existing pulmonary lesions (n?=?2), appearance of new pleural effusion (n?=?1) and prolonged high grade fever (n?=?2). Four patients developed new tubercular meningitis as manifestation of TB-IRIS. Our cases developed TB-IRIS a median of 15?days after starting ART (IQR 15?C36). TB-IRIS patients were older (> 35?years) than those with no IRIS (P?=?0.03), but were not distinguishable by CD4 T-cell count, duration of ATT before ART or the outcome of TB treatment. Eight (62%) patients had a complete recovery while 5 (38%) patients with TB-IRIS died, of which majority (n?=?3) had meningitis.

Conclusions

Paradoxical TB-IRIS is a frequent problem during concomitant ATT and ART in HIV-TB co infected patients in north India. Meningitis is a potentially life threatening manifestation of TB-IRIS.     

HLA-DR and HLA-DP Restricted Epitopes from Human Cytomegalovirus Glycoprotein B Recognized by CD4+ T-Cell Clones from Chronically Infected Individuals

Purpose

Helper CD4⁺ T cells presumably play a major role in controlling cytomegalovirus (CMV) by providing help to specific B and CD8⁺ cytotoxic T cells, as well as through cytotoxicity-mediated mechanisms. Since CMV glycoprotein B (gB) is a major candidate for a subunit vaccine against CMV, we searched for gB-epitopes presented by human leukocyte antigen (HLA)-class II molecules.

Methods

Dendritic cells obtained from CMV-seropositive donors were loaded with a recombinant gB and co-cultured with autologous CD4⁺ T cells. Microcultures that specifically recognized gB were cloned by limiting dilution using autologous Epstein-Barr virus (EBV)-immortalized B cells pulsed with gB as antigen-presenting cells. To pinpoint precisely the region encoding the natural epitope recognized by a given CD4⁺ clone, we assessed the recognition of recombinant Escherichia coli expressing gB-overlapping polypeptides after their processing by autologous EBV-B cells.

Results

We isolated several gB-specific CD4⁺ T-cell clones directed against peptides gB_190-204, gB_396-410, gB_22-36 and gB_598-617 presented by HLA-DR7, HLA-DP10 and HLA-DP2. While their precise role in controlling CMV infection remains to be established, gB-specific CD4⁺ T cells are likely to act by directly targeting infected HLA-class II cells in vivo, as suggested by their recognition of EBV-B cells infected by the Towne CMV strain.

Conclusions

The characterization of such gB-epitopes presented by HLA-class II should help to understand the contribution of CD4⁺ T-cell responses to CMV and may be of importance both in designing a vaccine against CMV infection and in immunomonitoring of subjects immunized with recombinant gB or with vectors encoding gB.     

Polyfunctional Analysis of Human Cytomegalovirus (HCMV)-Specific CD4+ and CD8+ Memory T-Cells in HCMV-Seropositive Healthy Subjects Following Different Stimuli

Purpose

Following primary human cytomegalovirus (HCMV) infection, both humoral and T-cell-mediated immune responses develop in immunocompetent subjects. However, while antibodies may be measured by different methodologies, the T-cell-mediated response remains to be analyzed in its polyfunctional aspects, in view of defining (following different stimuli) the optimal assay to monitor the HCMV-specific T-cell response in HCMV-seropositive subjects.

Methods

In a group of 30 HCMV-seropositive adults, T-cell response revealed by the HCMV-infected dendritic cell (iDC) stimulus was compared with those given by the HCMV-infected cell lysate (iCL), and by a 34-peptide pool (PP).

Results

All HCMV-seropositive subjects showed presence of both HCMV-specific CD4⁺ and CD8⁺ T-cells in peripheral blood following iDC stimulation. One subject did not respond to PP. As compared to iDC, the number of HCMV-specific stimulated T-cells/μl blood was slightly lower for iCL (P?=?0.195) and significantly lower for PP (P?=?0.001). Polyfunctional analysis of the T-cell response indicated that the lower number of CD4⁺ T-cells stimulated by iCL was due to the bifunctional (IFN-γ⁺ TNF-α⁺) and CD40L-negative T-cell reduction, while the reduction in specific PP-stimulated CD8⁺ T-cells was attributable to the reduction in tri-(IFN-γ⁺ TNF-α⁺ IL2⁺), bi-(IFN-γ⁺ TNF-α⁺) and mono-(IFN-γ⁺) functional T-cells. In addition, 15/30 (50 %) subjects showed a CD4⁺ cross-response to PP, and 11/30 (37 %) a CD8⁺ cross-response to iCL.

Conclusions

HCMV-specific stimulus given by iDC is not significantly different from that of iCL on CD4⁺ and is significantly superior to that of PP on CD8+ T-cells. However, iCL may contribute significantly to CD8⁺, and PP to CD4⁺ T-cell stimulation.     

<Emphasis Type="Italic">SERPING1</Emphasis> mRNA overexpression in monocytes from HIV+ patients

Objective

The HIV-1 virus activates the complement system, an essential element of the immune system. SERPING1 is a protease inhibitor that disables C1r/C1s in the C1 complex of the classical complement pathway.

Methods

In this paper, we performed an analysis of several microarrays deposited in GEO dataset to demonstrate that SERPING1 mRNA is modulated in CD14⁺ monocytes from HIV-1-infected individuals. In addition, data were validated on monocytes isolated from seronegative healthy volunteers, treated with IFNs.

Results

Our analysis shows that SERPING1 mRNA is overexpressed in monocytes from HIV-1+ patients and the expression levels correlate positively with viral load and negatively with the CD4⁺ T-cell count. Of note, anti-retroviral therapy is able to reduce the levels of SERPING1 mRNA, ex vivo. In addition, we found that 30% of the SERPING1 genes network is upregulated in monocytes from HIV-1+ patients. Noteworthy, the expression levels of IFITM1—an antiviral molecule belonging to the genes network—correlate positively with SERPING1 expression. Interestingly, the monocytes treatment with IFN-gamma, IFN-beta and IFN-alpha significantly upregulates the SERPING1 mRNA expression levels.

Conclusions

From the outcome of our investigation, it is possible to conclude that SERPING1 and its network serve as important components of the innate immune system to restrict HIV-1 infection.

     

Longitudinal Immune Responses and Gene Expression Profiles in Type 1 Leprosy Reactions

Purpose

Leprosy, a chronic disease initiated by Mycobacterium leprae, is often complicated by acute inflammatory reactions. Although such episodes occur in at least 50 % of all leprosy patients and may cause irreversible nerve damage, no laboratory tests are available for early diagnosis or prediction of reactions. Since immune- and genetic host factors are critical in leprosy reactions, we hypothesize that identification of host-derived biomarkers correlated to leprosy reactions can provide the basis for new tests to facilitate timely diagnosis and treatment thereby helping to prevent tissue damage.

Methods

The longitudinal host response of a leprosy patient, who was affected by a type 1 reaction (T1R) after MDT-treatment, was studied in unprecedented detail, measuring cellular and humoral immunity and gene expression profiles to identify biomarkers specific for T1R.

Results

Cytokine analysis in response to M. leprae revealed increased production of IFN-γ, IP-10, CXCL9, IL-17A and VEGF at diagnosis of T1R compared to before T1R, whereas a simultaneous decrease in IL-10 and G-CSF was observed at T1R. Cytokines shifts coincided with a reduction in known regulatory CD39⁺CCL4⁺ and CD25^high T-cell subsets. Moreover, RNA expression profiles revealed that IFN-induced genes, (V)EGF, and genes associated with cytotoxic T-cell responses (GNLY, GZMA/B, PRF1) were upregulated during T1R, whereas expression of T-cell regulation-associated genes were decreased.

Conclusions

These data show that increased inflammation, vasculoneogenesis and cytotoxicity, perturbed T-cell regulation as well as IFN-induced genes play an important role in T1R and provide potential T1R-specific host biomarkers.