Human immunodeficiency virus-1 infection protects against a Tc1-to-Tc2 shift in CD8(+) T cells

Despite the reports of dysfunction of the lytic abilities of CD8(+) T cells during human immunodeficiency virus-1 (HIV-1) disease progression, the effects of infection on the noncytolytic functions of CD8(+) T cells have not been well characterized to date. We examined the effect of HIV-1 infection on the cytokine and chemokine responses of peripheral blood-derived CD8(+) T cells in an in vitro system. Activation of HIV-1-infected CD8(+) T cells with phytohemagglutinin resulted in a 4- to 8-fold increase in the production of macrophage inflammatory protein (MIP)-1α, MIP-1β, regulated on activation normal T-cell expressed and secreted, and interleukin (IL)-16. Treatment of activated HIV-1-infected CD8(+) T cells with anti-CD3 monoclonal (M) antibody (Ab) and IL-15 induced strong production of interferon-γ (IFN-γ). Treatment of cells with anti-IL-12 MAb and IL-4 to induce a Tc1-to-Tc2 shift resulted in no change in viral production levels or IFN-γ production within the HIV-1-infected CD8(+) T cell population. Initiation of a Tc2-to-Tc1 shift resulted in a 6-fold increase in HIV-1 replication and 2- to 3-fold higher levels of IFN-γ, demonstrating that infection can protect against a Tc1-to-Tc2 shift in CD8(+) T cells.     

Increased Mycobacterium tuberculosis growth in HIV-1-infected human macrophages: role of tumour necrosis factor-alpha

Synergism between Mycobacterium tuberculosis (M. tuberculosis) and HIV-1 infections was demonstrated in several in vitro models and clinical studies. Here, we investigated their reciprocal effects on growth in chronically HIV-1-infected promonocytic U1 cells and in acutely infected monocyte-derived macrophages (MDM). Phagocytosis of M. tuberculosis induced HIV-1 expression in U1 cells, together with increased TNF-alpha production. M. tuberculosis growth, evaluated by competitive PCR, was greater in HIV-1-infected MDM compared to uninfected cells. M. tuberculosis phagocytosis induced greater TNF-alpha and IL-10 production in HIV-1-infected MDM than in uninfected cells. In uninfected MDM, addition of TNF-alpha and IFN-gamma decreased, whereas IL-10 increased M. tuberculosis growth. On the contrary, in HIV-1-infected MDM, addition of TNF-alpha and IFN-gamma increased, whereas IL-10 has no effect on M. tuberculosis growth. TNF-alpha seems to play a pivotal role in the enhanced M. tuberculosis growth observed in HIV-1-infected MDM, being unable to exert its physiological antimycobacterial activity. Here, for the first time we demonstrated an enhanced M. tuberculosis growth in HIV-1-infected MDM, in line with the observed clinical synergism between the two infections.     

Recombinant gp120 induces IL-10 in resting peripheral blood mononuclear cells; correlation with the induction of other cytokines.

Immunological abnormalities present in HIV-1-infected individuals often reflect an imbalance of cytokine production. The HIV-1 gp120 has the ability to induce a number of cytokines, and to enhance immunoglobulin release by normal peripheral blood mononuclear cells (PBMC) in vitro, in the absence of IL-2 production and of lymphoproliferation. This study provides evidence that gp120 is a potent IL-10 inducer in normal PBMC cultures. The pattern of other cytokines induced by gp120 includes interferon-alpha (IFN-alpha) and IFN-gamma, tumour necrosis factor-alpha (TNF-alpha), IL-6, IL-1 alpha and -beta, and not IL-2 and IL-4. These findings further define the pattern of cytokine release induced by gp120 on human resting PBMC. Furthermore, the present findings roughly parallel those observed both in the sera of patients and in the mononuclear cells from HIV+ individuals early after infection, suggesting that gp120 could be a good candidate as one of the agents responsible for cytokine dysregulation observed in HIV-1-infected individuals.     

Serum interleukin-6 (IL-6), IL-10, tumor necrosis factor (TNF) alpha, soluble type II TNF receptor, and transforming growth factor beta levels in human immunodeficiency virus type 1-infected individuals with Mycobacterium avium complex disease

To characterize changes in serum cytokine levels in human immunodeficiency virus type 1 (HIV-1)-infected persons with Mycobacterium avium complex (MAC) bacteremia, the levels of IL-1alpha (interleukin-1alpha), IL-6, IL-10, tumor necrosis factor alpha (TNF-alpha), soluble type II TNF receptor (sTNF-RII), and transforming growth factor beta (TGF-beta) in serum were measured in two cohorts of HIV-1-infected persons with MAC bacteremia. The first cohort was part of a MAC prophylaxis study. Patients with bacteremia were matched with controls without bacteremia. Elevated IL-6, IL-10, TNF-alpha, sTNF-RII, and TGF-beta levels were noted at baseline for all subjects, a result consistent with advanced HIV-1 disease. IL-1alpha was not detected. No differences in cytokine levels in serum were noted at baseline and at the time of bacteremia between patients with MAC and controls. In the second cohort, subjects had serum samples collected at the time of MAC bacteremia and thereafter while on macrolide therapy. Serum samples at time of bacteremia were collected from HIV-1-infected persons at a time when neither highly active antiretroviral therapy (HAART) nor MAC prophylaxis was used routinely. MAC treatment resulted in decreased levels of IL-6 and TNF-alpha in serum, which were evident for IL-6 by 4 to 6 weeks and for TNF-alpha by 8 to 16 weeks. Thus, antibiotic treatment for MAC results in decreased levels of IL-6 and TNF-alpha in serum in HIV-1-infected persons who are not on HAART.     

Mycobacterium avium infection in HIV-1-infected subjects increases monokine secretion and is associated with enhanced viral load and diminished immune response to viral antigens.

The complex interaction between HIV-1 infection and Mycobacterium avium was studied. Viral burden was assessed, as well as immune response to HIV-1 in the context of Myco. avium infections. We also examined serum cytokine levels and cytokine release by blood mononuclear cells in HIV-1-infected subjects, infected or not with Myco. avium. Undetectable serum levels of IL-1, tumour necrosis factor-alpha (TNF-alpha) and IL-6 were found in normal controls and in groups I, II and III of HIV-1-infected subjects. Moderate levels of TNF-alpha, IL-1 and IL-6 were found in the sera of group IV patients. When group IV was subdivided into subjects with and without Myco. avium infections, subjects with Myco, avium infections were shown to have higher serum levels of TNF-alpha, IL-1 beta and IL-6 than those with other infections. Blood mononuclear cells from controls and HIV subjects were stimulated with bacterial lipopolysaccharide, and cytokine levels assessed. Cells from group II patients were shown to secrete normal levels of TNF-alpha and IL-6, and lower levels of IL-1 beta; group III subjects released higher levels of IL-6. Patients in group IV had blood cells that released elevated levels of IL-6 and TNF-alpha, and lower levels of IL-1 beta. Group IV subjects with Myco. avium infections had blood cells that released higher levels of TNF-alpha, IL-6 and IL-1 than group IV subjects with other infections. Assessment of viral burden in cells of HIV-1-infected subjects revealed that Myco. avium-infected subjects had a higher level of virus burden and a lower level of lymphoproliferative response to an inactivated gp120-depleted HIV-1 antigen than AIDS subjects with other infections. These data suggest that Myco. avium infections in HIV-1-infected subjects hasten the progression of viral disease, enhance cytokine release and contribute to the anergy to viral antigens.     

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

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

Clinical relevance of cytokine production in HIV-1 infection in children on antiretroviral therapy

In order to investigate the correlation among cytokine production and antiretroviral therapy (ART), viral load, CD4(+) and CD8(+) T lymphocytes, 55 human immunodeficiency virus (HIV)-1-infected children on ART or not, and 16 uninfected controls were studied. Peripheral blood mononuclear cells (PBMCs) of HIV-1-infected children and controls were cultured and spontaneous and mitogen-stimulated cytokines production was quantified in the supernatants. Viral load was quantified using standard molecular assay. CD4 and CD8 T-lymphocyte counts were determined by flow cytometry. Cytokine production by mitogen-stimulated PBMCs showed different profiles in HIV-1 children whether treated or not. The tumour necrosis factor (TNF)-alpha production was higher and the interleukin (IL)-10 production was lower in the HIV-1-untreated group than in the HIV-1-treated children and controls. The IL-2 production was reduced and the RANTES production was higher in both HIV-1 groups compared with the controls. The interferon (IFN)-gamma and the IL-5 production was significantly reduced in the HIV-1-treated children compared to the controls. Interestingly, the analysis of the correlation of HIV-1 phenotype with cytokine production indicated an increased RANTES production in relation to nonsyncytium-inducing viral phenotype with slow/low replication profile, whereas decreased IL-10 levels was associated to syncytium-inducing (SI) strains and rapid/high replication. Our findings suggest that AVT changes on the cytokine and chemokine production play an important role in the HIV pathogenesis.     

Cytokines involved in the progression of multiple myeloma.

We have investigated which of the cytokines that are relevant in the in vitro growth of multiple myeloma (MM) malignant plasma cells are actually produced in vivo by MM patients. To this end, we have measured the levels of IL-1 beta, IL-3, IL-4, IL-6, IL-7, IL-8 and tumour necrosis factor-alpha (TNF-alpha) both in sera and in the supernatant of bone marrow (BM) stromal cell cultures from patients with MM and monoclonal gammopathy of undetermined significance (MGUS). The significance of our findings is three-fold. First, IL-6 and IL-8 are produced by MM BM stromal cells, while IL-1 beta, TNF-alpha, IL-4 and IL-7 are not. Second, IL-3 is the only cytokine consistently raised in serum samples: we have also detected low levels of serum IL-6 in a minority of cases, usually in advanced stage of the disease. Third, MM BM stromal cells are active IL-6 and IL-8 producers, while both normal and MGUS BM stromal cells are low producers, thus suggesting that in the BM of MM a number of environmental cells, that would normally be quiescent, are instead activated and that, in MM, activated BM stromal cells play an active role in supporting the progressive expansion of the B cell clone.     

In vivo cytokine-associated responses to biomaterials

Cytokines, chemokines, and growth factors were analyzed periodically over eight weeks from the wound exudate fluid surrounding biomaterials implanted subcutaneously within stainless steel mesh cages. TNF-alpha, MCP-1, MIP-1alpha, IL-2, IL-6, IL-1beta, VEGF, IL-4, and IL-10 were measured from exudate samples collected from cages containing specimens of polyethylene (PE), polyurethane (PU), or organotin polyvinyl chloride (ot-PVC). Empty cages served as negative controls, and lipopolysaccharide (LPS) served as a positive control. Cytokine, chemokine, and growth factor concentrations decreased from the time of implantation to eight weeks post-implantation, and there was an overall increase in cytokine, chemokine, and growth factor production for material-containing cages compared to empty cages. However, cytokine production was only modestly affected by the different surface chemistries of the three implanted polymeric materials.     

Characterization of the main placental cytokine profiles from HIV-1-infected pregnant women treated with anti-retroviral drugs in France

Cytokines are involved in regulating HIV-1 infection. They are also placental environment major components. We assessed the potential impact of HIV-1 infection and/or anti-retroviral drugs on the placental cytokine profiles that may be involved in controlling HIV-1 placental dissemination. Placental explants were obtained after elective caesarean section from anti-retroviral-treated HIV-1-infected pregnant women and from HIV-1 non-infected pregnant women. The main placental cytokines were assessed for protein secretion in the supernatants of 24-h placental culture explants and/or in uncultured placental explants for mRNA expression levels. The cytokine profiles were different between the HIV-1-infected and the non-infected groups. Higher medians of leukaemia inhibiting factor (LIF), tumour necrosis factor (TNF)-alpha and interleukin (IL)-8 secretion were found in the 24-h culture supernatant of term placenta from HIV-1-infected women. High median levels of IL-16 and regulated upon activation normal T cell expressed and secreted (RANTES) levels were found in both groups. The mRNA expression medians were lower for TNF-alpha and IL-8 and higher for stromal cell-derived factor-1 (SDF-1) in uncultured placental explants from HIV-1-infected women. In the HIV-1-infected group, but not in the non-infected group, the secretion levels of TNF-alpha and IL-8, as well as their mRNA expression levels, were highly positively correlated; furthermore, their secretion levels were correlated positively with LIF and IL-10 secretion levels. We found no correlation between the cytokine levels and the immunovirological status of the HIV-1-infected mothers or the type or duration of treatment. These results highlight the potential impact of HIV-1 and of the anti-retroviral treatments on the placental cytokines pattern, independently of their anti-viral activity.     

Cytomegalovirus blocks intestinal stroma-induced down-regulation of macrophage HIV-1 infection

Intestinal macrophages, unlike macrophages from other tissues, do not support HIV-1 infection or produce proinflammatory cytokines. In vitro studies suggest this unique, functional phenotype is a result of the exposure of newly recruited blood monocytes to intestinal stromal products. However, in AIDS-related CMV colitis, mucosal macrophages express HIV-1 and proinflammatory cytokines. Therefore, we investigated the mechanism by which CMV confers permissiveness to HIV-1 and cytokine production on intestinal macrophages. We show that intestinal stroma-conditioned media (S-CM) down-regulated monocyte-derived macrophage infection by HIV-1 (pseudotyped with YU2 envelope or vesicular stomatitis virus glycoprotein) and production of TNF-alpha, but preinfection of the cells with CMV reversed this down-regulation, enhancing HIV-1 infection, p24 production, and TNF-alpha release. The ability of CMV to reverse S-CM down-regulation of macrophage HIV-1 infection was blocked by anti-TNF-alpha antibodies and over-ridden by exogenous TNF-alpha. Immunohistochemical analysis of monocyte-derived macrophages exposed to CMV and HIV-1 (YU2 pseudotype) revealed that the cells infrequently contained CMV and HIV-1 viral proteins. In addition, analysis of colon tissue sections from HIV-1-infected patients with CMV colitis showed that some macrophage-like cells contained CMV and TNF-alpha proteins, others contained HIV-1 and TNF-alpha proteins, but cells infrequently contained CMV and HIV-1 proteins. These results indicate that CMV blocks stromal product inhibition of HIV-1 infection in macrophages, and this inhibition is mediated, at least in part, by CMV-induced TNF-alpha acting in trans to enhance HIV-1 infection.     

Progressive and selective impairment of IL-3 and IL-4 production by peripheral blood CD4+ T-lymphocytes during the course of HIV-1 infection.

The amounts of interleukin 3 (IL-3), interleukin 4 (IL-4), tumor necrosis factor alpha (TNF-alpha), and tumor necrosis factor beta (TNF-beta) were evaluated by immunoenzymatic assays in the supernatant of short-term cultures of whole mononuclear cells and purified CD4+ T-lymphocytes, obtained from the peripheral blood (PB) of 35 HIV-1(+) asymptomatic individuals (stages I-II of the Walter Reed Classification), 20 HIV-1(+) symptomatic patients (WR V-VI), and 40 HIV-1(-) blood donors. TNF-alpha and TNF-beta production was similar in HIV-1(+) asymptomatic individuals, HIV-1(+) symptomatic patients, and HIV-1(-) controls. On the other hand, IL-3 and IL-4 production by either whole mononuclear cells or isolated CD4+ T-cells was decreased approximately 2-fold (p < 0.01) in HIV-1(+) asymptomatic subjects with respect to HIV-1(-) blood donors and was very low or almost absent in HIV-1(+) symptomatic individuals. The reduced IL-3 and IL-4 production in HIV-1-infected subjects correlated not only with the stage of the disease, but also with signs of active viral replication in PB cells, monitored by gag p24 antigen in plasma and viral isolation from PB mononuclear cells. This selective and progressive impairment in IL-3 and IL-4 production by CD4+ T-lymphocytes of HIV-1-infected subjects may contribute to explain the hematopoietic abnormalities and the derangement of the inflammatory/immune system characteristic of AIDS.     

Interleukin-17 augments tumor necrosis factor-alpha-induced elaboration of proangiogenic factors from fibroblasts

Interleukin-17 (IL-17) is a CD4 T cell cytokine. In this report, we investigated the effects of this cytokine on the elaboration of proangiogenic factors by lung fibroblasts. After stimulation with a wide range of doses of IL-17, fibroblasts produced more amount of various kinds of angiogenic factors including NO, HGF, MCP-1, KC, MIP-2, PGE1, PGE2 and VEGF in a dose-dependent manner. Treatment with a COX-1 and COX-2 inhibitor indomethacin did not impair IL-17-induced HGF and VEGF secretion in fibroblasts. In addition, TNF-alpha alone stimulated the elaboration of KC, MIP-2, PGE2 and VEGF in fibroblasts. IL-17 and TNF-alpha in combination up-regulated elaboration of these proangiogenic factors additively or synergistically. Moreover, conditioned media (CM) from IL-17-stimulated fibroblasts showed significantly higher activity on endothelial cell growth than those from non-treated control cells. These results indicate that IL-17 up-regulates elaboration of various proangiogenic factors, and modulates macrophage-derived TNF-alpha-induced production of KC, MIP-2, PGE2 and VEGF by fibroblasts. Our findings also demonstrate that IL-17 might be a potential contributor to the inflammatory angiogenesis via induction of proangiogenic factors by stromal fibroblasts.     

Activation of human microglial cells by HIV-1 gp41 and Tat proteins

The viral proteins, Tat (HIV-1 nuclear protein) and gp41 (HIV-1 coat protein), detected in the brains of HIV-1-infected patients have been shown to be neurotoxic. We investigated the effects of HIV-1 Tat and gp41 proteins on cytokine, chemokine, and superoxide anion (O(-)(2)) production by microglia, the resident macrophages of the brain. Tat and gp41 dose-dependently stimulated cytokine and chemokine production by microglia. Peak production of these cytokines and chemokines differed in microglial cells treated with gp41 and Tat. Expression of cytokine and chemokine mRNA was also stimulated in gp41- and Tat-treated microglia. Neither gp41 nor Tat alone stimulated O(-)(2) production by microglia. Treatment of microglial cells with Tat but not with gp41 evoked an increase in intracellular Ca(2+). The results of this study suggest that HIV-1 Tat and gp41 proteins impact several key functions of microglial cells which could contribute to the neuropathogenesis of HIV-1.     

Multiplex analysis of cytokines, chemokines, growth factors, MMP-9 and TIMP-1 produced by human bone marrow, adipose tissue, and placental mesenchymal stromal cells

Comparative analysis of mesenchymal stromal cells isolated from human BM, adipose tissue, and placenta was carried out. The cells were compared by the levels of constitutive, spontaneous, and LPS-induced production of Th1/proinflammatory (IFN-γ, IL-2, IL-1β, TNF-α, IL-12, IL-17) and Th2/anti-inflammatory cytokines (IL-4, IL-5, IL-6, IL-10, IL-13), chemokines (IL-8, MCP-1, MIP-1β), growth factors (IL-7, granulocytic CSF, granulocytic macrophageal CSF, erythropoietin, VEGF, EGF, IGF-1, main FGF), matrix metalloproteinase-9, and tissue inhibitor of metalloproteinase-1. Mesenchymal stromal cells originating from different tissues were characterized by functional potential for hemopoiesis support (through production of granulocytic CSF, granulocytic macrophage CSF, erythropoietin), immunomodulation (through production of IFN-γ, IL-2, IL-6, IL-1β, TNF-α and chemokines IL-8, MCP-1, MIP-1β), and stimulation of reparative processes (through production of VEGF, FGF, IGF-1, IL-6 tissue inhibitor of metalloproteinase-1, and matrix metalloproteinase-9). By the type and levels of spontaneous (basal) production of cytokines, the adipose tissue mesenchymal stromal cells more distinctly demonstrated the proinflammatory (IL-1β TNF-α), immunoregulatory (IFN-γ, IL-2, IL-4, IL-6, IL-8, MCP-1, MIP-1β), and hemopoiesis-stimulating (granulocytic CSF, granulocytic macrophage CSF) phenotype and at the same time were characterized by lower sensitivity to lipopolysaccharide stimulation than BM and placental mesenchymal cells.     

Differential regulation of lipopolysaccharide and Gram-positive bacteria induced cytokine and chemokine production in macrophages by Galpha(i) proteins

Heterotrimeric G(i) proteins play a role in signalling activated by lipopolysaccharide (LPS), Staphylococcus aureus (SA) and group B streptococci (GBS), leading to production of inflammatory mediators. We hypothesized that genetic deletion of G(i) proteins would alter cytokine and chemokine production induced by LPS, SA and GBS stimulation. LPS-induced, heat-killed SA-induced and heat-killed GBS-induced cytokine and chemokine production in peritoneal macrophages from wild-type (WT), Galpha(i2) (-/-) or Galpha(i1/3) (-/-) mice were investigated. LPS induced production of tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), IL-10 and interferon-gamma-inducible protein-10 (IP-10); SA induced TNF-alpha, and IL-1beta production; and GBS induced TNF-alpha, IL-6, IL-1beta, macrophage inflammatory protein-1alpha (MIP-1alpha) and keratinocyte chemoattract (KC) production were all decreased (P < 0.05) in Galpha(i2) (-/-) or Galpha(i1/3) (-/-) mice compared with WT mice. In contrast to the role of G(i) proteins as a positive regulator of mediators, LPS-induced production of MIP-1alpha and granulocyte-macrophage colony-stimulating factor (GM-CSF) were increased in macrophages from Galpha(i1/3) (-/-) mice, and SA-induced MIP-1alpha production was increased in both groups of Galpha(i) protein-depleted mice. LPS-induced production of KC and IL-1beta, SA-induced production of GM-CSF, KC and IP-10, and GBS-induced production of IL-10, GM-CSF and IP-10 were unchanged in macrophages from Galpha(i2) (-/-) or Galpha(i1/3) (-/-) mice compared with WT mice. These data suggest that G(i2) and G(i1/3) proteins are both involved and differentially regulate murine inflammatory cytokine and chemokine production in response to both LPS and Gram-positive microbial stimuli.