Quantitative analysis of Tr1 lymphocytes in patients with type 2 diabetes mellitus.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is usually accompanied by a low-grade inflammatory phenomenon, which participates in the pathogenesis of different complications of this condition. The inflammatory response is under the regulation of different mechanisms, including T regulatory (Treg) lymphocytes. However, the possible role of type 1 T regulatory (Tr1) cells in T2DM has not been explored so far. AIM: To carry out a quantitative analysis of Tr1 lymphocytes and other immune cell subsets in patients with T2DM and correlate these results with clinical findings and treatments. MATERIALS AND METHODS: Sixty patients with T2DM and twenty-three healthy controls were included in the study. Biochemical and anthropometric variables were evaluated, and Tr1 lymphocytes (CD4+CD49+LAG-3+IL-10+) and other cell subsets (Th17, Th22 and Foxp3 + Treg cells) were analyzed in peripheral blood samples by multiparametric flow cytometry. RESULTS: Significant increased levels of Tr1 cells were detected in patients with severe and mild disease, compared to healthy controls. In addition, CD4+IL-10+ lymphocytes were also increased in patients with T2DM. In contrast, similar levels of Foxp3+ Treg cells, Th17 and Th22 lymphocytes were observed in patients and controls. Likewise, no significant associations were detected between Tr1 cell levels and different clinical and laboratory parameters. However, those patients receiving glucagon-like peptide-1 receptor agonists (GLP-1-RA) showed similar levels of Tr1 cells than healthy controls, and significant lower numbers than untreated patients. CONCLUSION: We observed an increase in Tr1 and CD4+IL10+ lymphocyte levels in T2DM. Moreover, GLP1-RA treatment was significantly associated with normalization of the Tr1 levels. This highlights another potential immune dysfunction in patients with T2DM, which could participate in the pathogenesis of this condition.

IMscin001 Part 2: a randomised phase III, open-label, multicentre study examining the pharmacokinetics, efficacy, immunogenicity, and safety of atezolizumab subcutaneous versus intravenous administration in previously treated locally advanced or metastatic non-small-cell lung cancer and pharmacokinetics comparison with other approved indications.

BACKGROUND: Atezolizumab intravenous (IV) is approved for the treatment of various solid tumours. To improve treatment convenience and health care efficiencies, a coformulation of atezolizumab and recombinant human hyaluronidase PH20 was developed for subcutaneous (SC) use. Part 2 of IMscin001 (NCT03735121) was a randomised phase III, open-label, multicentre, noninferiority study comparing the drug exposure of atezolizumab SC with atezolizumab IV. PATIENTS AND METHODS: Eligible patients with locally advanced/metastatic non-small-cell lung cancer were randomised 2 : 1 to receive atezolizumab SC (1875 mg; n = 247) or IV (1200 mg; n = 124) every 3 weeks. The co-primary endpoints were cycle 1 observed trough serum concentration (Ctrough) and model-predicted area under the curve from days 0 to 21 (AUC0-21 d). The secondary endpoints were steady-state exposure, efficacy, safety, and immunogenicity. Exposure following atezolizumab SC was then compared with historical atezolizumab IV values across approved indications. RESULTS: The study met both of its co-primary endpoints: cycle 1 observed Ctrough {SC: 89 µg/ml [coefficient of variation (CV): 43%] versus IV: 85 µg/ml (CV: 33%); geometric mean ratio (GMR), 1.05 [90% confidence interval (CI) 0.88-1.24]} and model-predicted AUC0-21 d [SC: 2907 µg d/ml (CV: 32%) versus IV: 3328 µg d/ml (CV: 20%); GMR, 0.87 (90% CI 0.83-0.92)]. Progression-free survival [hazard ratio 1.08 (95% CI 0.82-1.41)], objective response rate (SC: 12% versus IV: 10%), and incidence of anti-atezolizumab antibodies (SC: 19.5% versus IV: 13.9%) were similar between arms. No new safety concerns were identified. Ctrough and AUC0-21 d for atezolizumab SC were consistent with the other approved atezolizumab IV indications. CONCLUSIONS: Compared with IV, atezolizumab SC demonstrated noninferior drug exposure at cycle 1. Efficacy, safety, and immunogenicity were similar between arms and consistent with the known profile for atezolizumab IV. Similar drug exposure and clinical outcomes following SC and IV administration support the use of atezolizumab SC as an alternative to atezolizumab IV.

Bacteria associated with apical periodontitis promotes in vitro the differentiation of macrophages to osteoclasts.

OBJECTIVE: To analyze the possible in vitro effect of the cytokine RANKL and bacteria involved in apical periodontitis on the differentiation of macrophages into osteoclasts. MATERIAL AND METHODS: Bacteria were isolated (mainly E. faecium and E. faecalis) from the root canal of fifty patients with apical periodontitis, the possible effect of these bacteria on the phagocytic activity of the monocyte cell line THP-1 was analyzed by flow cytometry. Furthermore, the effect of these bacteria (alone or in combination with the cytokine RANKL) on the differentiation of THP-1 macrophages into osteoclasts was analyzed through the expression of the receptor RANK and the tartrate-resistant acid phosphatase TRAP. Finally, the release of different cytokines (IL-1ß, TNF-α, IL-6, IL-8, IL-10, and IL-12p70) by THP-1 cells induced to differentiate into osteoclasts was also analyzed. RESULTS: We observed a significant proportion of THP-1 cells were able to internalize E. faecium and E. faecalis. Furthermore, these bacteria were able to induce (alone or in combination with RANKL) a significant expression of RANK by THP-1 macrophages; accordingly, E. faecium and E. faecalis induced very significant levels of TRAP in these cells. Finally, during the differentiation of THP-1 macrophages induced by RANKL or bacteria, a significant release of the pro-inflammatory cytokines IL-6 and TNF-α was observed. CONCLUSIONS AND CLINICAL RELEVANCE: Our data suggest that the causative agents of apical periodontitis can induce the differentiation of osteoclasts as well as the release of pro-inflammatory cytokines, phenomena that may have an important role in the bone damage observed in this condition.

Analysis of the regulatory function of natural killer cells from patients with systemic lupus erythematosus.

Natural killer (NK) cells participate in the regulation of the immune response. However, the immunomodulatory function of NK cells in systemic lupus erythematosus (SLE) is not well understood. The aim of this study was to evaluate the regulatory function of NK cells in SLE patients and to identify the NK cells involved in the pathogenesis of this complex disease. We analysed the expression of NK receptors and co-stimulatory molecules in peripheral NK cells (CD3- CD56+ ) from SLE patients, as well as the numbers of human leucocyte antigen D-related (HLA-DR)/CD11c+ NK cells. In addition, NK cell regulatory function was assessed by the detection of NK cell-mediated dendritic cell (DC) lysis. We found that SLE patients showed increased numbers of immunoglobulin-like transcript 2 (ILT2)+ , CD86+ and CD134+ NK cells. Furthermore, NK cells from SLE patients induced higher levels of DC lysis. We were able to identify a new subset of NK cells co-expressing CD11c and HLA-DR. These atypical NK cells were increased in SLE patients when compared with controls. We have identified an expanded new subset of NK cells in SLE patients. This is the first study, to our knowledge, which demonstrates that NK cells in SLE patients have an altered phenotype with a high expression of receptors characteristic of dendritic cells. Our results suggest that the impairment in the regulatory function of NK cells, together with the increased number of DC-like NK cells, could play an important role in the development of SLE and highlight the importance of NK cells as a future therapeutic target.

Proportions of several types of plasma and urine microparticles are increased in patients with rheumatoid arthritis with active disease.

We analysed the proportions of different microparticles (MPs) in plasma from patients with rheumatoid arthritis (RA), and assessed their relationship with disease activity/therapy and their in-vitro effect on proinflammatory cytokine release. Blood and urine samples were obtained from 55 patients with RA (24 untreated and 31 under conventional therapy) and 20 healthy subjects. Fourteen patients with systemic lupus erythematosus (SLE) were also studied. The proportions of CD3(+) , CD14(+) , CD19(+) , CD41(+) and CD62E(+) MPs were determined by flow cytometry analysis. The in-vitro effect of plasma MPs on the release of interleukin (IL)-1, IL-6, IL-17 and tumour necrosis factor (TNF)-α was also analysed. We detected that the proportions of different types of annexin-V(+) MPs were enhanced in plasma (CD3(+) , CD14(+) , CD19(+) , CD41(+) and CD62E(+) MPs) and urine (CD14(+) , CD3(+) and CD19(+) MPs) from RA patients with high disease activity (DAS28 index > 5·1). Accordingly, a significant positive correlation was observed between the levels of MPs and DAS28 score, and these levels diminished significantly at week 4 of immunosuppressive therapy. Finally, MPs isolated from patients with high disease activity induced, in vitro, an enhanced release of IL-1, IL-17 and TNF-α. In SLE, enhanced levels of different types of plasma MPs were also detected, with a tight correlation with disease activity. Our data further support that MPs have a relevant role in the pathogenesis of RA and suggest that the analysis of the proportions of these microvesicles in plasma could be useful to monitor disease activity and therapy response in patients with RA.

Analysis of expression and function of the co-stimulatory receptor SLAMF1 in immune cells from patients with systemic lupus erythematosus (SLE).

The signaling lymphocytic activation molecule SLAMF1 (CD150) is a co-stimulatory molecule that is expressed by most immune cells, including T regulatory (Treg) lymphocytes. Since different abnormalities have been reported regarding the number and function of Foxp3+ Treg cells in patients with systemic lupus erythematosus (SLE), we decided to analyze the expression and function of CD150 in these regulatory lymphocytes in this condition. We isolated peripheral blood mononuclear cells from 20 patients with SLE, and 20 healthy controls. The expression of SLAMF1 was determined by multi-parametric flow cytometry and the suppressive function of CD4+CD25+ lymphocytes, upon engagement or not of CD150 with an agonistic monoclonal antibody, was analyzed by an assay of inhibition of cell proliferation. We observed a significantly increased expression of SLAMF1 by CD3+CD4+ helper T cells and CD19+ B cells in patients with SLE and active disease. However, similar levels of SLAMF1 expression were detected in Foxp3+ Treg cells from patients and controls. In contrast, a higher proportion of SLE patients increased their suppressive function of Treg cells upon CD150 engagement compared to healthy controls. Our data suggest that SLAMF1 is another significant piece in the intricate defective immune-regulatory function of patients with SLE.

Involvement of cell adhesion and activation molecules in the pathogenesis of erythema dyschromicum perstans (ashy dermatitis). The effect of clofazimine therapy.

OBJECTIVES: To assess the expression of several cell adhesion and lymphocyte activation molecules in erythema dyschromicum perstans lesions, and to evaluate the effect of clofazimine therapy on the expression of these molecules. DESIGN AND METHODS: A prospective study. Skin biopsy samples were obtained from patients before and after 3 months of clofazimine therapy, and the expression of cell adhesion and activation molecules was assessed by an immunohistochemical technique. SETTING: This study was performed in a clinical referral center and an immunology research laboratory. PATIENTS: We studied 6 patients with erythema dyschromicum perstans. A diagnosis was made on the basis of clinical and histological criteria. Two patients discontinued participation in the study: one because of adverse effects and the other for unknown reasons. INTERVENTIONS: Patients were treated with clofazimine, 100 mg/d, for 3 months. MAIN OUTCOME MEASURES: Expression of cell adhesion and lymphocyte activation molecules in skin biopsy specimens before and after clofazimine therapy. RESULTS: Before clofazimine therapy, we detected a noticeable expression of intercellular adhesion molecule 1 and major histocompatibility complex class II molecules (HLA-DR) in the keratinocyte basal cell layer. In addition, CD36, a thrombospondin receptor that is not expressed by normal skin, was detected in the strata spinosum and granulosum. The dermal cell infiltrate expressed the activation molecule AIM/CD69 and the cytotoxic cell marker CD94. After clofazimine therapy, the expression of intercellular adhesion molecule 1 and HLA-DR disappeared, as well as the mononuclear cell infiltrate. CONCLUSIONS: Our results suggest that some cell adhesion and activation molecules are involved in the pathogenesis of erythema dyschromicum perstans. Clofazimine appears to have an important effect on the inflammatory phenomenon of erythema dyschromicum perstans.

An immunohistochemical study of UV-induced skin lesions in actinic prurigo. Resistance of langerhans cells to UV light.

Actinic prurigo is an inflammatory disease of the skin that appears to be mediated by an abnormal immune response. Cell adhesion molecules play a key role in the induction of the immune response as well as in the pathogenesis of inflammation. We investigated the expression of cell adhesion and activation molecules, as well as the density of Langerhans cells in skin from patients with actinic prurigo. Skin biopsies from ultraviolet light-induced lesions, and non-irradiated areas from 10 actinic prurigo patients were studied; in addition, several spontaneous skin lesions were studied. Skin biopsies from normal individuals were used as controls. The expression of ICAM-1, ICAM-3, LFA-3, CD2, LFA-1, VLA-4, CD1a, VCAM-1, CD69, and activated b1 integrins were assessed by immunostaining. An increased expression of LFA-1, LFA-2, ICAM-3, VLA-4, and activated b1 integrins was observed in the cell infiltrate of actinic prurigo lesions and an up-regulated expression of ICAM-1 was detected in keratinocytes from these specimens. Interestingly, the number of Langerhans cells (CD1a + ) in actinic prurigo skin was not significantly affected by ultraviolet irradiation, a phenomenon that was not observed in normal controls. The increased expression of adhesion molecules in the cell infiltrate of actinic prurigo, indicates that these cells are activated and suggests that they are involved in the skin damage seen in these patients. The resistance of Langerhans cells from patients with actinic prurigo to ultraviolet light may have an important role in the pathogenesis of this condition. The involvement of keratinocytes in the pathogenesis of actinic prurigo is suggested by the expression of ICAM-1 on these cells.

Plasma levels and in vitro production of tumor necrosis factor-alpha and interleukin-6 in patients with amebic liver abscess.

We studied the plasma levels of tumor necrosis factor-alpha (TNF-alpha) interleukin-6 (IL-6) as well as the in vitro production of these cytokines by peripheral blood mononuclear cells, in 10 patients with amebic liver abscess (ALA) and seven healthy controls. TNF-alpha was measured using a bioassay with L929 fibroblasts; IL-6 was quantitated by the B9 cell line assay. In both assays, the number of viable cells was estimated by the conversion of MTT to formazan. TNF-alpha plasma levels were nondetectable (< 20 pg/mL) in ALA patients, as well as in the majority of healthy controls. The in vitro production of TNF induced by lipopolysaccharide was significantly decreased in ALA patients. Most ALA patients (8/10) had increased plasma levels of IL-6. Furthermore, the spontaneous production of IL-6 in vitro was significantly increased in ALA patients compared to controls. In the acute stage of the ALA, a negative relationship was found between the raised plasma levels of IL-6 and the in vitro diminished production of TNF-alpha. After recovery, ALA patients showed both normal plasma levels and in vitro production of TNF and IL-6. Our data corroborate previous reports regarding plasma levels of TNF in ALA, and suggest that E. histolytica induces the in vivo production of IL-6 through a TNF-independent pathway. The raised levels of IL-6 might in turn down-regulate the production of TNF in ALA patients.

Natural killer cell-mediated cytotoxicity in cryptococcal meningitis.

There are evidences regarding the role of NK cytotoxic activity in the resistance against experimental C. neoformans infection. To assess the status of NK cell activity in human C. neoformans infection, we studied the peripheral blood of twelve patients with cryptococcal meningitis, six patients with CNS disease different to cryptococcal meningitis, and twelve healthy subjects. The number of CD16+cells and the NK cytotoxic activity of peripheral blood mononuclear cells was studied. The in vitro effect of exogenous IL-2 and interferon gamma on such cytotoxic activity was also studied. The number of CD16+ cells was not significantly different in patients compared to controls. However, cryptococcal patients exhibited a significant lower NK activity compared to both control groups (p less than 0.05 in both cases). The low NK activity of cryptococcal patients was fully reconstituted in vitro with the addition of rIL-2 but not with rIFN gamma. In vitro experiments suggest that the low NK activity of cryptococcal meningitis patients is not due to amphotericin B therapy or blockade of NK cells by C. neoformans-derived molecules. The results of this study suggests that patients with cryptococcal meningitis have a defective NK cytotoxic function and may aid to understand the pathogenesis of this disease.

Decreased blood levels of B lymphocytes and NK cells in patients with systemic lupus erythematosus (SLE) infected with papillomavirus (HPV).

Patients with systemic lupus erythematosus (SLE) show an enhanced risk to develop human papillomavirus (HPV) infection, and aggressive forms of this condition are seen in these patients. The aim of this study was to assess the possible relationship among HPV infection, immunosuppressive therapy and levels of leukocyte subsets in patients with SLE. The following individuals were included in the study: (1) SLE patients under immunosuppressive therapy and with lesions caused by HPV (n = 16); (2) SLE patients under immunosuppressive therapy and no evidence of HPV infection (n = 20); (3) untreated SLE patients with no evidence of HPV infection (n = 7), and; (4) healthy female subjects without evidence of HPV infection (n = 10). Peripheral blood was obtained and the percentages of different lymphocyte subsets were determined by flow cytometry, with the use of the following monoclonal antibodies: CD3, CD4, CD8, CD16, CD19, CD20, CD22, CD56, and CD335 (NKp46). We found that SLE patients under immunosuppressive therapy and with lesions caused by HPV showed significantly lower levels of B lymphocytes and NK cells compared to other groups. In contrast, SLE patients receiving immunosuppressive drugs and with no evidence of HPV infection showed similar levels of B and NK cells than healthy controls. Those patients receiving mycophenolate mofetil (MMF) had a diminished number of B cells, and a positive correlation was detected between the dose of MMF and the number of HPV skin lesions. Our data suggest that therapy of SLE patients with MMF is associated with diminished levels of B and NK cells and an enhanced risk for HPV infection.

Human papillomavirus immunization is associated with increased expression of different innate immune regulatory receptors.

Human papillomavirus (HPV) is able to inhibit the secretion of gamma interferon (IFN-γ) and the expression of some immune innate cell receptors. Immunoglobulin-like transcript 2 (ILT2) is a regulatory receptor that seems to participate in the pathogenesis of viral infections. We have studied the expression and function of ILT2 and the expression of other NK cell receptors in 23 healthy women before and after immunization with the quadrivalent HPV (type 6/11/16/18) vaccine (Gardasil). Receptor expression was analyzed by flow cytometry in freshly isolated peripheral blood mononuclear cells as well as after in vitro stimulation with the quadrivalent HPV (type 6/11/16/18) vaccine. In addition, the regulatory function of ILT2 on cell proliferation and IFN-γ production was analyzed. We found a significant increase in the expression of ILT2 by NK and CD3(+) CD56(+) lymphocytes and monocytes after quadrivalent HPV (type 6/11/16/18) vaccine immunization. In addition, the in vitro stimulation with the quadrivalent HPV (type 6/11/16/18) vaccine also increased the proportion of CD3(-) CD56(+) ILT2(+) NK cells. Although the inhibitory function of ILT2 on cell proliferation was enhanced after HPV immunization, the in vitro engagement of this receptor did not affect the synthesis of IFN-γ induced by HPV. Finally, a significant increase in the expression of NKG2D, NKp30, and NKp46 by NK and CD3(+) CD56(+) lymphocytes was detected after quadrivalent HPV (type 6/11/16/18) vaccine immunization. Our data indicate that HPV immunization is associated with significant changes in the expression and function of different innate immune receptors, including ILT2, which may participate in the protective effect of HPV vaccines.

[Role of paediatrics in primary care and coordination with specialist care]. / Papel del pediatra de atención primaria y coordinación con atención especializada.

OBJECTIVES: Primary care (PC) paediatricians are trained mainly in the hospital setting, with little contact with PC. This study aimed to find out what perceptions and experiences they have on the attributes of PC (first contact, comprehensiveness and continuity of care) that are assumed and performed by PC paediatricians. MATERIAL AND METHODS: A qualitative study was performed based on focus groups and semi-structured individual interviews with paediatricians with pre-defined sociodemographic and speciality training characteristics. Two focus groups (5 and 4 people each) and 5 interviews were made. Participants responded to two questions: how would you explain your function as a primary care paediatrician? and what is your opinion on the relationship between primary care paediatricians and the specialists to whom your patients are referred? The conversations of the groups and interviews were recorded and transcribed, and a content analysis was performed. RESULTS: Paediatricians assume that PC must be comprehensive, and take into account the context of the child. Paediatricians declare a lack in their training and poor social and institutional recognition. Coordination with specialists and the transfer of information are not satisfactory. Helpful factors are personal knowledge, the shared training and the face-to-face clinical sessions. CONCLUSION: Despite their hospital-based training, paediatricians assume the attributes of PC. Difficulties in performing their function include poor adaptation of their training to PC, and little institutional and social recognition. Coordination with specialists is not satisfactory. Approaching these difficulties can help maintaining a high quality level in the care of the paediatric population.

Analysis of expression and function of the inhibitory receptor ILT2 (CD85j/LILRB1/LIR-1) in peripheral blood mononuclear cells from patients with systemic lupus erythematosus (SLE).

The aim of this work was to study the expression and function of the inhibitory receptor ILT2/CD85j in peripheral blood mononuclear cells (PBMC) from patients with systemic lupus erythematosus (SLE). We studied 23 SLE patients as well as 17 patients with rheumatoid arthritis, 10 with fibromyalgia, and 23 healthy individuals. We found a variable level of expression of ILT2 in the PBMC from both SLE patients and controls, with no significant differences among them. However, when the expression of this receptor was assessed in cell subsets, significantly lower levels were detected in CD19+ lymphocytes from SLE patients compared with healthy controls. Functional assays performed in unfractionated PBMC, showed a significant diminished inhibitory activity of ILT2 in CD4+ and CD8+ cell subsets from SLE patients compared to either rheumatoid arthritis or fibromyalgia patients, and healthy individuals. Our results show that the PBMC from some patients with SLE show a defective expression of ILT2, and that most of them exhibit a poor function of this inhibitory receptor.

P2X7 and NRAMP1/SLC11 A1 gene polymorphisms in Mexican mestizo patients with pulmonary tuberculosis.

Tuberculosis remains one of the most important infectious diseases worldwide. Several studies have suggested that genetic factors may affect susceptibility to tuberculosis, but the specific genes involved have not yet been fully characterized. NRAMP1/SLC11 A1 and P2X(7) genes have been linked to increased risk for tuberculosis in some African and Asiatic populations. To explore the potential role of these genes in the susceptibility to pulmonary tuberculosis in a Mexican mestizo population, we evaluated the association of D543N and 3'-UTR polymorphisms in NRAMP1/SLC11 A1 and - 762 and A1513C polymorphisms in P2X(7) genes with the risk for tuberculosis. Polymerase chain reaction (PCR) amplification of genomic DNA followed by restriction fragment length polymorphism analysis, and allelic-specific PCR was employed. We found no significant differences in allelic frequency in NRAMP1/SLC11 A1 gene polymorphisms in 94 patients with tuberculosis compared to 100 healthy contacts. Similarly, no significant association of the P2X(7)-762 gene polymorphism with tuberculosis was detected. In contrast, the P2X(7) A1513C polymorphism was associated significantly with tuberculosis (P = 0.02, odds ratio = 5.28, 95% CI, 0.99-37.69), an association that had not been reported previously. However, when the function of P2X(7) was assessed by an L-selectin loss assay, we did not find significant differences in patients compared to healthy contacts or between PPD(+) and PPD(-) control individuals. This study further supports the complex role of P2X(7) gene in host regulation of Mycobacterium tuberculosis infection, and demonstrates that different associations of gene polymorphisms and tuberculosis are found in distinct racial populations.

Expression and function of IL-10R in mononuclear cells from patients with systemic lupus erythematosus.

OBJECTIVE: To assess the expression and function of the receptor for interleukin-10 (IL-10R) in immune cells from patients with systemic lupus erythematosus (SLE). METHODS: We assessed the expression and function of IL-10R in peripheral blood mononuclear cells (PBMCs) from 19 SLE patients and 15 healthy controls. The expression of IL-10R was assessed by flow cytometry, and the function of this receptor was determined by analysing both the activation of Jak-1, Tyk-2, Stat-1, and Stat-3 (Western blot) and the induction of gene expression (cDNA array test of 242 genes of cytokines, apoptosis and intracellular signalling) upon stimulation with IL-10. RESULTS: We found similar levels of IL-10R expression in SLE patients and controls. In addition, variable levels of Jak-1, Tyk-2, Stat-1, and Stat-3 activation were induced by IL-10 in PBMCs from SLE patients and controls, with no significant differences in protein phosphorylation or kinetics of activation. However, clear-cut differences in the gene expression induced through IL-10R were observed in SLE patients and controls, mainly in the genes involved in apoptosis and those encoding for cytokines and their receptors. CONCLUSIONS: Our data suggest that despite normal levels of IL-10R expression, and an apparent lack of abnormalities in the intracellular signals induced through this receptor, immune cells from SLE patients exhibit an aberrant pattern of gene expression induced through the IL-10R.

Expression and function of the purinergic receptor P2X7 in patients with pulmonary tuberculosis.

P2X(7) is a channel receptor gated by adenosine triphosphate (ATP) that is involved in the killing of intracellular mycobacteria. To explore further the role of P2X(7) in immunity against Mycobacterium tuberculosis, we studied its expression and function in 19 patients with pulmonary tuberculosis (TB) and 19 healthy contacts. Flow cytometry analysis showed a similar and variable expression of P2X(7) in TB patients and healthy subjects. In contrast, P2X(7) mARN levels were significantly higher in TB patients. When the function of the P2X(7) receptor in peripheral blood mononuclear cells (PBMC) was assessed by the effect of exogenous ATP on apoptosis, the uptake of the fluorescent marker Lucifer yellow or extracellular signal regulated kinase (ERK) phosphorylation, no significant differences were detected in patients and controls. However, mRNA macroarray analysis showed that upon stimulation with ATP, the PBMC from TB patients showed a significant induction of a higher number of cytokine genes (27 of 96), and a lower number of apoptosis genes (20 of 96) compared to healthy controls (17 and 76 genes, respectively). These results suggest that although the PBMC from TB patients do not show apparent abnormalities in the expression of P2X(7), and the intracellular signals generated through it, the pattern of gene expression induced by ATP in these cells is different from that found in healthy contacts. This phenomenon suggests a defective function of P2X(7) in the immune cells from TB patients, a condition that may contribute to the inability of these patients to eliminate the mycobacteria.