Two distinct cell populations are obtained from human blood monocytes cultured with M-CSF, GM-CSF and IL-4

Brief Report: Peripheral Monocyte/Macrophage Phenotypes Associated With the Evolution of Cognitive Performance in HIV-Infected Patients

BACKGROUND

The contribution of monocyte activation in the development of HIV-associated neurocognitive disorders is not completely understood. This study aimed to explore the predictive value of peripheral monocyte/macrophage (M/M) phenotypes on the evolution of cognitive performance in a population of virologically suppressed HIV-infected patients.

SETTING

Prospective, observational, longitudinal study.

METHODS

HIV-1-infected patients with HIV-RNA <50copies/mL for >12 months underwent neuropsychological examination at baseline and after 1 year. Cognitive performance was evaluated using Z-transformed scores, and neurocognitive impairment (NCI) was defined according to Frascati criteria. Peripheral M/M phenotypes (classic CD14CD16, intermediate CD14CD16, and nonclassic CD14CD16) and specific surface activation markers (eg, CD163, CD11b, and CD38) were evaluated using flow cytometry at baseline. Predictive value of peripheral M/M phenotypes on the evolution of cognitive performance over 1-year follow-up was also evaluated.

RESULTS

Overall, 54 patients [85.2% men, median age 50 years (range 27-60 years), 27.8% hepatitis C virus coinfected, 48.1% with past AIDS-defining events, median nadir CD4 83 cells/μL (range 1-334), median baseline CD4 547 cells/μL (range 136-1652)] were enrolled. Proportion of patients with NCI was low, accounting for 13% at baseline and 16.5% after 1 year (P = 0.687). Memory was the only single domain in which decreased performance after 1 year was observed (-0.25 Z-score, P = 0.025). In patients with significant decrease (≥0.5 SD) in memory performance (n = 20), significantly lower CD14CD16CD163 (% CD14CD16) (P = 0.038) and higher CD14CD38 (% CD14) (P = 0.030) levels were observed.

CONCLUSIONS

In virologically suppressed HIV-infected patients, the evolution of memory performance could be linked to the expression of certain peripheral activated M/M phenotypes. Such associations should be verified in larger populations over the long term.

Casein α s1 is expressed by human monocytes and upregulates the production of GM-CSF via p38 MAPK

Caseins are major constituents of mammalian milks that are thought to be exclusively expressed in mammary glands and to function primarily as a protein source, as well as to ameliorate intestinal calcium uptake. In addition, proinflammatory and immunomodulatory properties have been reported for bovine caseins. Our aim was to investigate whether human casein α s1 (CSN1S1) is expressed outside the mammary gland and possesses immunomodulatory functions in humans as well. For this purpose, CSN1S1 mRNA was detected in primary human monocytes and CD4(+) and CD8(+) T cells, but not in CD19(+) B cells. CSN1S1 protein was traceable in supernatants of cultured primary human CD14(+) monocytes by ELISA. Similarly, CSN1S1 mRNA and protein were detected in the human monocytic cell lines HL60, U937, and THP1 but not in Mono Mac 6 cells. Moreover, permeabilized human monocytes and HL60 cells could be stained by immunofluorescence, indicating intracellular expression. Recombinant human CSN1S1 was bound to the surface of Mono Mac 6 cells and upregulated the expression of GM-CSF mRNA in primary human monocytes and Mono Mac 6 cells in a time- and concentration-dependent manner. A similar increase in GM-CSF protein was found in the culture supernatants. CSN1S1-dependent upregulation of GM-CSF was specifically blocked by the addition of the p38 MAPK inhibitor ML3403. Our results indicated that human CSN1S1 may possess an immunomodulatory role beyond its nutritional function in milk. It is expressed in human monocytes and stimulates the expression of the proinflammatory cytokine GM-CSF.

Elevated gelatinase activity in pulmonary alveolar proteinosis: role of macrophage-colony stimulating factor

Pulmonary alveolar proteinosis (PAP) is an anti-granulocyte macrophage-colony stimulating factor (GM-CSF) autoimmune disease resulting in the accumulation of phospholipids in the alveoli. GM-CSF knockout (KO) mice exhibit a strikingly similar lung pathology to patients with PAP. The lack of functionally active GM-CSF correlates with highly elevated concentrations of M-CSF in the lungs of PAP patients and GM-CSF KO mice. M-CSF has been associated with alternative macrophage activation, and in models of pulmonary fibrosis, M-CSF also contributes to tissue resorption and fibrosis. Matrix metalloproteinase-2 (MMP-2) and MMP-9 have been implicated in extracellular matrix degradation in animal models of fibrosis and asthma. We show for the first time that the lungs of PAP patients contain highly elevated levels of MMP-2 and MMP-9. PAP broncholaveolar lavage (BAL) cells but not bronchial epithelial cells expressed increased MMP-2 and MMP-9 mRNA relative to healthy controls. Both MMPs were detectable as pro and active proteins by gelatin zymography; and by fluorometric global assay, PAP-MMP activity was elevated. BAL cells/fluids from GM-CSF KO mice also demonstrated significantly elevated MMP-2 and MMP-9 gene expression, protein, and activity. Finally, PAP patients undergoing GM-CSF therapy exhibited significantly reduced MMPs and M-CSF. These data suggest that in the absence of GM-CSF, excess M-CSF in PAP may redirect alveolar macrophage activation, thus potentially contributing to elevated MMP expression in the lung.

Recombinant vaccinia virus encoding human MUC1 and IL2 as immunotherapy in patients with breast cancer

Polymorphic epithelial mucin, encoded by the MUC1 gene, is present at the apical surface of glandular epithelial cells. It is over-expressed and aberrantly glycosylated in most breast tumors, resulting in an antigenically distinct molecule and a potential target for immunotherapy. This transmembrane protein, when produced by tumor cells, is often cleaved into the circulation, where it is detectable as a tumor marker (CA 15.3) by various antibodies, allowing for early detection of recurrences and evaluation of treatment efficacy. The objective of the current study was to examine the clinical and environmental safety and immunogenicity of a live recombinant vaccinia virus expressing the human MUC1 and IL2 genes (VV TG5058), referred to here as TG1031. The study was an open-label phase 1 and 2 trial in nine patients with advanced inoperable breast cancer recurrences to the chest wall. The patients were vaccinated intramuscularly with a single dose of TG1031; three patients were treated at each of three progressive dose levels ranging from 5x10(5) to 5x10(7) plaque-forming units. A boost injection at their original dose level was administered in patients responding immunologically, clinically, or both. Vaccination resulted in no significant clinical adverse effects, and there was no environmental contamination by live TG1031. All patients had been vaccinated as children, and patients treated at the highest dose level mounted a significant anti-vaccinia antibody response. None of the nine patients had a significant increase in MUC1-specific antibody titers after one single injection, whereas five patients had a detectable increase in vaccinia virus antibody titers. Peripheral blood mononuclear cells of one patient at the intermediate dose level showed a proliferative response to in vitro culture with vaccinia virus, with a stimulation index of 6. A second patient treated at the intermediate dose level had a stimulation index of 7 to MUC1 peptide and of 14 after a boost injection. This patient had a concomitant decrease in carcinoembryonic antigen serum levels and remained clinically stable for 10 weeks. Evidence of MUC1-specific cytotoxic T lymphocytes was detected in two patients. Immunohistochemical analysis revealed an increase in T memory cells (CD45RO) in tumor biopsies after vaccination. The absence of serious adverse events, together with the documentation of immune stimulations in vivo, warrant the further use of TG1031 in immunotherapy trials of breast cancer.