Biomarkers of Progression after HIV Acute/Early Infection: Nothing Compares to CD4⁺ T-cell Count?

Progression of HIV infection is variable among individuals, and definition disease progression biomarkers is still needed. Here, we aimed to categorize the predictive potential of several variables using feature selection methods and decision trees. A total of seventy-five treatment-naïve subjects were enrolled during acute/early HIV infection. CD4⁺ T-cell counts (CD4TC) and viral load (VL) levels were determined at enrollment and for one year. Immune activation, HIV-specific immune response, Human Leukocyte Antigen (HLA) and C-C chemokine receptor type 5 (CCR5) genotypes, and plasma levels of 39 cytokines were determined. Data were analyzed by machine learning and non-parametric methods. Variable hierarchization was performed by Weka correlation-based feature selection and J48 decision tree. Plasma interleukin (IL)-10, interferon gamma-induced protein (IP)-10, soluble IL-2 receptor alpha (sIL-2Rα) and tumor necrosis factor alpha (TNF-α) levels correlated directly with baseline VL, whereas IL-2, TNF-α, fibroblast growth factor (FGF)-2 and macrophage inflammatory protein (MIP)-1ß correlated directly with CD4⁺ T-cell activation (p < 0.05). However, none of these cytokines had good predictive values to distinguish "progressors" from "non-progressors". Similarly, immune activation, HIV-specific immune responses and HLA/CCR5 genotypes had low discrimination power. Baseline CD4TC was the most potent discerning variable with a cut-off of 438 cells/µL (accuracy = 0.93, κ-Cohen = 0.85). Limited discerning power of the other factors might be related to frequency, variability and/or sampling time. Future studies based on decision trees to identify biomarkers of post-treatment control are warrantied.

Acute response of peripheral CCr5 chemoreceptor and NK cells in individuals submitted to a single session of low-intensity strength exercise with blood flow restriction.

The purpose of this study was to compare the peripheral expression of natural killers and CCR5 in a session of low-intensity strength training with vascular occlusion and in high-intensity training. Young males were randomized into session groups of a high-intensity strength training (HI) and a session group of low-intensity strength training with vascular occlusion (LI-BFR). The exercise session consisted in knee extension and bicep curl in 80% 1RM (HI) and 30% 1RM (LI-BFR) with equalized volumes. Blood collection was made before, immediately after and 24 h after each training session. Immunophenotyping was carried out through CD195+ (CCR5) e CD3-CD16+CD56+ (NK) in peripheral blood and analysed by flow cytometry and presented in frequency (%). Peripheral frequency of NK cells showed no significant difference in LI-BFR group in time effect, while a gradual reduction of NK cells was identified in HI group in before-24 h postexercise and after-24 h postexercise comparison. However, significant differences have been found in relative change of NK cells immediately after exercise between sessions. In addition, HI and LI-BFR groups showed a significant reduction in the cells expressed CCR5 during 24 h postsession compared to the postsession, but CCR5 also differed when comparing before-24 h after session in the HI group. No differences were observed amongst the groups. LIO induced CCR5 response similar to the HI session, while the NK cells remained in similar frequency during the studied moments in LI-BFR, but not in HI group, suggesting that local hypoxia created by the blood flow restriction was able to prevent a change in the frequency of peripheral cells and a possible immunosuppression.

Expression of resistin, CXCR3, IP-10, CCR5 and MIP-1α in obese patients with different severity of asthma.

Asthma studies suggest that alteration in the inflammation pattern may be associated with the severity of asthma. The aim of this study was to compare in vitro the expression of chemokines, chemokine receptors and cytokine production from CD4+ T human lymphocytes of asthmatic, both obese and non-obese patients with different severity levels of asthma. Lymphocytes were labeled with monoclonal anti-human CXCR3/IP-10, MIP-1a/CCR5 antibodies and were analyzed by flow cytometry. Cell culture supernatants were used to measure production of interleukin IL-6 and resistin by ELISA. CXCR3/IP-10 expression increased in non-obese patients with mild persistent asthma (2.2%, p<0.05), moderate persistent asthma (3%, p<0.003) and severe persistent asthma (4%, p<0.004); this effect was stronger in obese patients with severe persistent asthma (35%, p<0.004). MIP-1 α / CCR5 increased in non-obese patients with intermittent asthma (0.65%, p<0.05) and severe asthma (1.4%, p<0.03); in obese patients, this expression was greater in intermittent asthma (8%, p<0.05) and severe persistent asthma (12%, p<0.04). Resistin production strongly increased in obese patients with intermittent (976 ng/ml) and severe persistent asthma (795 ng/ml). IL-6 increased in both lean and obese persons; however, the highest value was registered in the group of severe persistent obese asthmatics (992 pg/ml). Obesity per se increased the inflammatory profile of chemokines / cytokines secreted by cells of the blood, increasing the inflammatory status in asthmatic patients. Resistin showed characteristics of a pro-inflammatory cytokine mainly in severely obese asthmatics.

Analysis of chemokine receptors on the surface of circulating leukocytes of individuals infected with Mycobacterium leprae: preliminary results.

In this study, the expression of chemokine receptors on the surface of circulating leukocytes was determined using flow cytometry. An increase in the percentage of CCR2+CD4+ lymphocytes was observed in the peripheral blood of leprosy patients. This preliminary data suggests that alterations occur in the chemokine receptor profile of these patients.

The beta-chemokines MIP-1alpha and RANTES and lipoprotein metabolism in HIV-infected Brazilian patients.

HIV patients are predisposed to the development of hypertriglyceridemia and hypercholesterolemia as a result of both viral infection and HIV infection therapy, especially the protease inhibitors. Chemokines and cytokines are present at sites of inflammation and can influence the nature of the inflammatory response in atherosclerosis. We investigated the correlation between biochemical variables and beta-chemokines (MIP-1alpha and RANTES) and the apolipoprotein E genotype in HIV-infected individuals. The apolipoproteins were measured by nephelometry. Triglycerides and total cholesterol were determined by standard enzymatic procedures. The beta-chemokines were detected by ELISA. The genetic category of CCR5 and apolipoprotein E were determined by PCR amplification and restriction enzymes. Immunological and virological profiles were assessed by TCD(4)+ and TCD(8)+ lymphocyte counts and viral load quantification. Positive correlations were found between apo E and CD(8)+ (p = 0.035), apo E and viral load (p = 0.018), MIP-1alpha and triglycerides (p = 0.039) and MIP-1a and VLDL (p = 0.040). Negative correlations were found between viral load and CD(4)+ (p = 0.05) and RANTES and CD(4)+ (p = 0.029). The beta-chemokine levels may influence lipid metabolism in HIV-infected individuals.

CXCR4 and CCR5 regulation and expression patterns on T- and monocyte-macrophage cell lineages: implications for susceptibility to infection by HIV-1.

Chemokine receptor expression may vary dramatically among cell subsets. Therefore, the stage of differentiation and the lineage of CD4 cells may profoundly affect their susceptibility to infection by human immunodeficiency virus type 1 (HIV-1). However, the mechanisms of coreceptor competition for association with HIV-1 glycoproteins remain unknown. Here, we propose mathematical models that address the interdependence of the concentrations of CD4 and CCR5 for efficient infection by M-tropic HIV-1 as well as additional complications originated by coreceptor competition caused by posttranslational modifications that positively or negatively affect the coreceptor ability to form complexes with CD4 and/or HIV-1 envelope. Furthermore, since CCR5 and CXCR4 expression on human leukocytes designate these cells as HIV-1 potential targets, the expression of the major HIV-1 coreceptors are also dynamically modeled/quantified as function of the stage of cell differentiation. Results show that although coreceptor competition degree has limited influence on R5 strain infectivity, the infectivity of CXCR4-using isolates strongly depends on the CD4 expression, according to the coreceptor competition model proposed in Lee et al. [J. Virol. 74(11) (2000) 5016]. Understanding the role of in vivo alterations in CD4, CCR5 and CXCR4 densities on HIV-1 cell entry may help the development of optimal control strategies for AIDS pathogenesis.

Participation of RANTES and T-cell apoptosis in human renal allograft.

The aim of this study was to evaluate the serum RANTES (Regulated upon Activation of Normal T cell Expressed and Secreted) levels and the expression of CCR5, as well as the percentage of apoptotic cells, in peripheral T lymphocytes from renal transplanted patients with acute rejection (AR), chronic rejection (CR) or stable evolution (SE). RANTES serum levels were determined by enzyme-linked immunoadsorbent assay and CCR5 expression, as well as the percentage of apoptotic lymphocytes, on a FACScan flow cytometer. After staining with different antibodies, the cells were subjected to three-colour flow cytometric analysis. Data analysis was performed using winmdi 2.5 software. The serum RANTES level and percentages of CCR5/CD4 and CCR5/CD8 T lymphocytes in CR, AR and SE were lower than that in the control group (P <0.05). The level of CD4 and CD8 T lymphocytes in early apoptosis was higher in AR patients than in CR, SE or C groups (P <0.05). In the case of late apoptosis, the percentage of apoptotic/necrotic cells was higher in the CR than AR, SE or C groups (P <0.05). The RANTES serum levels and the percentage of peripheral CCR5 T lymphocytes would not indicate the renal allograft state. The increase of early apoptotic T lymphocytes could be a marker of AR process and could also indicate the initial step in reducing the cytotoxic T lymphocytes, thus favouring the graft evolution.

Chemokine receptor expression on the surface of peripheral blood mononuclear cells in Chagas disease.

We evaluated the expression of chemokine receptors (CCR1, CCR2, CCR5, and CXCR4) on the surface of peripheral blood mononuclear cells obtained from patients with chronic chagasic cardiomyopathy (CCC) and noninfected individuals. Only CCR5 and CXCR4 expression was different on the surface of the subsets (CD4, CD8, and CD14) evaluated. Patients with mild CCC had elevated leukocyte expression of CCR5, compared with noninfected individuals or those with severe disease. CXCR4 expression was lower on leukocytes from patients with severe CCC. The differential expression of both receptors on leukocytes of patients with CCC was consistent and clearly correlated with the degree of heart function such that the lower the heart function, the lower the expression of either CCR5 or CXCR4. These results highlight the possible participation of the chemokine system in early forms of chagasic cardiomyopathy and the relevance of heart failure-induced remodeling in modifying immune parameters in infected individuals.