Pretreatment levels of soluble cellular receptors and interleukin-6 are associated with HIV disease progression in subjects treated with highly active antiretroviral therapy

BACKGROUND

To identify inflammatory pathways that may contribute to the pathogenesis of human immunodeficiency virus (HIV) disease, we explored associations between AIDS or death and different inflammatory markers, including selected soluble tumor necrosis factor superfamily receptors (sTNFRs) and ligands, interleukin (IL)-6, and CD8 T cell activation, in individuals treated with highly active antiretroviral therapy (HAART).

METHODS

A case-control study of subjects in AIDS Clinical Trials Group (ACTG) protocols 384 and 5015, who were matched according to the CD4 cell count and plasma viral load at baseline, was performed using conditional logistic regression.

RESULTS

Higher pretreatment concentrations of sTNFR-1, sCD27, sCD40L, and plasma IL-6 were associated with a new AIDS-defining illness or death in separate models adjusted for age, sex, hemoglobin, and the latest CD4 cell counts. In additional models that excluded case patients with opportunistic infections, sTNFR-1, sCD27, and sCD40L were each associated with a new AIDS-defining malignancy or death that developed at a median of 51 weeks after initiation of HAART, by which time the majority of subjects had a CD4 cell count of >200 cells/cm(3) and had achieved a plasma viral load of <50 copies/mL.

CONCLUSION

These data are compatible with a model in which these soluble inflammatory markers identify pathways that may contribute to the pathogenesis of HIV disease progression, pathways that might not be a direct consequence of ongoing HIV type 1 replication.

Incomplete reconstitution of T cell subsets on combination antiretroviral therapy in the AIDS Clinical Trials Group protocol 384

BACKGROUND

Initiation of combination antiretroviral therapy (ART) results in higher total CD4 cell counts, a surrogate for immune reconstitution. Whether the baseline CD4 cell count affects reconstitution of immune cell subsets has not been well characterized.

METHODS

Using data from 978 patients (621 with comprehensive immunological assessments) from the AIDS [Acquired Immunodeficiency Syndrome] Clinical Trials Group protocol 384, a randomized trial of initial ART, we compared reconstitution of CD4(+), CD4(+) naive and memory, CD4(+) activation, CD8(+), CD8(+) activation, B, and natural killer cells among patients in different baseline CD4(+) strata. Reference ranges for T cell populations in control patients negative for human immunodeficiency virus (HIV) infection were calculated using data from AIDS Clinical Trials Group protocol A5113.

RESULTS

Patients in the lower baseline CD4(+) strata did not achieve total CD4(+) cell counts similar to those of patients in the higher strata during 144 weeks of ART, although CD4(+) cell count increases were similar. Ratios of CD4(+) naive-memory cell counts and CD4(+):CD8(+) cell counts remained significantly reduced in patients with lower baseline CD4(+) cell counts (

CONCLUSIONS

After nearly 3 years of ART, T cell subsets in patients with baseline CD4(+) cell counts >350 cells/mm(3) achieved or approached the reference range those of control individuals without HIV infection. In contrast, patients who began ART with Collapse

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MESH Headings

• Acquired Immunodeficiency Syndrome/drug therapy
• Acquired Immunodeficiency Syndrome/immunology
• Adult
• Antiretroviral Therapy, Highly Active
• B-Lymphocytes/immunology
• CD4 Lymphocyte Count
• CD4-CD8 Ratio
• Female
• Humans
• Killer Cells, Natural/immunology
• Male
• Middle Aged
• T-Lymphocyte Subsets/immunology

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Grants

• AI25879 NIAID NIH HHS
• AI066992 NIAID NIH HHS
• K01 AI062435-02 NIAID NIH HHS
• R01 AI066992 NIAID NIH HHS
• U01 AI038858 NIAID NIH HHS
• AI27659 NIAID NIH HHS
• AI38855 NIAID NIH HHS
• IP30AI060354 NIAID NIH HHS
• U01 AI025879 NIAID NIH HHS
• K01 AI062435 NIAID NIH HHS
• AI27666 NIAID NIH HHS
• AI38858 NIAID NIH HHS
• K01 AI062435-04 NIAID NIH HHS
• U01 AI038855 NIAID NIH HHS
• K01 AI062435-03 NIAID NIH HHS
• K01AI062435 NIAID NIH HHS
• U01 AI027666 NIAID NIH HHS
• K01 AI062435-01A1 NIAID NIH HHS
• U01 AI027659 NIAID NIH HHS
• P30 AI060354 NIAID NIH HHS

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Quantum dot dipole orientation and excitation efficiency of micropillar modes

The relative intensity of photonic modes in microcavity pillars with embedded self-assembled quantum dots is shown to be a sensitive function of quantum dot dipole orientation and position. This is deduced from a comparison of experiment and calculated intensities of light emission for many nominally identical pillars. We are able to obtain the overall degree of in-plane polarization of the quantum dot ensemble and also to obtain information on the degree of polarization along the growth axis.

Identification of a tetrapeptide recognition sequence for the alpha 2 beta 1 integrin in collagen

The alpha 2 beta 1 integrin serves as either a specific cell surface receptor for collagen or as both a collagen and laminin receptor depending upon the cell type. Recently we established that the alpha 2 beta 1 integrin binds to a site within the alpha 1 (I)-CB3 fragment of type I collagen (Staatz, W. D., Walsh, J. J., Pexton, T., and Santoro, S. A. (1990) J. Biol. Chem. 265, 4778-4781). To define the alpha 2 beta 1 recognition sequence further we have prepared an overlapping set of synthetic peptides which completely spans the 148-amino acid alpha 1(I)-CB3 fragment and tested the peptides for ability to inhibit cell adhesion to collagen and laminin substrates. The minimal active recognition sequence defined by these experiments is a tetrapeptide of the sequence Asp-Gly-Glu-Ala (DGEA) corresponding to residues 435-438 of the type I collagen sequence. The DGEA-containing peptides effectively inhibited alpha 2 beta 1-mediated Mg2(+)-dependent adhesion of platelets, which use the alpha 2 beta 1 integrin as a collagen-specific receptor, to collagen but had no effect on alpha 5 beta 1-mediated platelet adhesion to fibronectin or alpha 6 beta 1-mediated platelet adhesion to laminin. In contrast, with T47D breast adenocarcinoma cells, which use alpha 2 beta 1 as a collagen/lamin receptor, adhesion to both collagen and laminin was inhibited by DGEA-containing peptides. Deletion of the alanine residue or substitution of alanine for either the glutamic or aspartic acid residues in DGEA-containing peptides resulted in marked loss of inhibitory activity. These results indicate that the amino acid sequence DGEA serves as a recognition site for the alpha 2 beta 1 integrin complex on platelets and other cells.