| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
(Circulation. 2002;106:1127.)
© 2002 American Heart Association, Inc.
Basic Science Reports |
From the Departments of Medicine (B.J.V.L., A.C.W., S.H., M.N., A.M.F.), Pathology and Laboratory Medicine (M.C.F.), and Microbiology, Immunology, and Molecular Genetics (D.P.N., L.A.), University of California at Los Angeles, and the Departments of Medicine, Biochemistry, and Molecular Genetics and the Atherosclerosis Research Unit (G.M.A., D.W.G.), University of Alabama, Birmingham.
Correspondence to Brian J. Van Lenten, PhD, Room 47-123 CHS, Division of Cardiology, Department of Medicine, UCLA School of Medicine, 10833 Le Conte Ave, Los Angeles, CA 90095-1679. E-mail bvanlent{at}mednet.ucla.edu
| Abstract |
|---|
|
|
|---|
Methods and Results D-4F, an apolipoprotein A-I mimetic peptide, or vehicle in which it was dissolved (PBS) was administered daily to LDL receptornull mice after a Western diet and after influenza infection. D-4F treatment increased plasma HDL cholesterol and paraoxonase activity compared with PBS and inhibited increases in LDL cholesterol and peak levels of interleukin-6 after infection. Lung viral titers were reduced by 50% in mice receiving D-4F. Injection of female mice with male macrophages, which were detected with real-time polymerase chain reaction to measure the male Sry gene, revealed a marked increase in macrophage traffic into the aortic arch and innominate arteries after infection that was prevented by administration of D-4F.
Conclusions We conclude that loss of antiinflammatory properties of HDL after influenza infection in mice is associated with increased arterial macrophage traffic that can be prevented by administration of D-4F.
Key Words: atherosclerosis infection lipoproteins interleukins
| Introduction |
|---|
|
|
|---|
We recently reported that after influenza infection in mice, HDL lost its antiinflammatory properties.4 As a result, the ability of HDL to protect against LDL oxidation in vitro was lost. Because the single most important determinant of plaque vulnerability to rupture is the intensity of monocyte/macrophage infiltration into the plaque,58 we hypothesized that alterations in HDL during an acute-phase response might predispose to increased risk for atherosclerotic clinical events by increasing monocyte/macrophage trafficking into arteries.
Patel and coworkers9 previously described an in vivo model that demonstrated homing of peritoneal macrophages labeled with fluorescent microspheres to atherosclerotic plaques. Kim et al10 recently developed a highly sensitive method based on the polymerase chain reaction (PCR) to quantitatively track DNA-marked monocytes in mice. In the present study, using a combination of the techniques of Patel et al9 and Kim et al,10 we observed that during influenza infection in LDL receptornull mice after a Western diet, there was a dramatic increase in macrophage infiltration into the aortic arch and innominate artery that was prevented by daily injection of an apolipoprotein A-I (apoA-I) mimetic peptide, D-4F.11
| Methods |
|---|
|
|
|---|
Influenza Inoculation
Mice were inoculated nasally with influenza virus strain A/WSN/33 as previously described.4
Lipoproteins, Cocultures, Monocyte Chemotaxis
Lipoproteins,12 cocultures,13 and monocytes14 were prepared and monocyte chemotaxis assays were performed as described.4
Preparation of T Cells
Jurkat clone E6-1 cells were obtained from ATCC and maintained in RPMI 1640 medium with 2 mmol/L L-glutamine adjusted to contain 1.5 g/L sodium bicarbonate, 4.5 g/L glucose, 10 mmol/L HEPES, and 1.0 mmol/L sodium pyruvate, plus 10% FBS. Cells were activated for 6 hours by addition of Phaseolus vulgaris leukophytohemagglutinin (1 µg/mL; Sigma) and phorbol myristate acetate (5 ng/mL; Sigma). Cells were washed 3 times in PBS, fixed with 1% paraformaldehyde for 2 hours at 4°C, and again washed 3 times before use.
Synthesis and Administration of ApoA-I Mimetic Peptide
In preliminary studies, we found that injection of human apoA-I prevented macrophage trafficking into the arteries of mice much less than did injection of an apoA-I mimetic peptide, D-4F. D-4F was synthesized as described.11,15 Mice were injected intraperitoneally with 20 µg of D-4F in 200 µL PBS or PBS alone daily, or PBS with 50 µg serum albumin. No difference was seen with PBS alone or PBS plus serum albumin. A peptide containing the same number of D-amino acids as in D-4F but in a scrambled sequence did not bind lipids and was used as a control in some in vitro studies.
Histological Analysis
At the time the mice were euthanized, lungs were perfused with 10% buffered formalin through the trachea. Microscopic analysis of complete sections of entire lungs revealed 3 different patterns of inflammation: perivascular chronic inflammatory cell infiltrates; acute pneumonia (infiltrates of neutrophils) in alveolar spaces; and lymphoid hyperplasia, circumscribed interstitial aggregates of lymphoid cells. Each of these 3 patterns was graded as to severity by a blinded observer.
Macrophage Preparation
Peritoneal macrophages were prepared as described by Patel et al.9 Forty-eight hours before euthanasia, female LDL receptornull mice were injected with 10x106 peritoneal macrophages from male donors in a volume of 200 µL saline via tail vein. After euthanasia, the mice were exsanguinated, the heart was perfused, and the aortic arch including the innominate artery was dissected and removed. Tissue DNA was extracted with a Qiagen DNeasy Tissue Kit (Qiagen).
Real-Time PCR to Quantitatively Track DNA-Marked Macrophages
DNA was quantified by real-time PCR on an ABI Prism 7700 Sequence Detector (Taqman, Perkin-Elmer Applied Biosystems) according to Kim et al.10 Sense and antisense primers used to amplify the Sry gene and the fluorescent probe were identical to those reported by Kim et al.10 As an external standard, ß-globin was coamplified with a sense primer corresponding to nucleotides 2998 to 3019 (5'-CATGGGTAATGCCAAAGTGAAG-3') and an antisense primer corresponding to nucleotides 3051 to 3070 (5'-CAAGTGATTCAGGCCATCGT-3'). The probe for ß-globin corresponded to nucleotides 3021 to 3046 (5'-CCCATGGCAAGAAGT- GATAACTGCC-3'). The quantity of male DNA in recipient female aortic arch and innominate artery was calculated and normalized to the amount of ß-globin. To evaluate the effects of cytokines on arterial macrophage trafficking, 200 ng each of mouse recombinant tumor necrosis factor-
and interleukin (IL)-6 (Biosource) was injected intraperitoneally in a total volume of 0.5 mL saline containing 1% BSA 30 minutes after injection of macrophages.
Other Procedures
Paraoxonase activity was measured as previously described.16 Plaque assays were used to determine lung viral titers.17 IL-6, IL-10, and granulocyte-macrophage colonystimulating factor (GM-CSF) were measured with ELISA kits (Biosource). Lipoprotein cholesterol concentrations were determined with a Cholesterol-20 kit (Sigma). Ouchterlony and Dot Blot analyses were used for detection of plasma IgG and IgM antibodies to D-4F. Statistical significance was determined with model I ANOVA, and significance was defined as a value of P<0.05.
| Results |
|---|
|
|
|---|
|
D-4F Treatment Suppresses the Cytokine Response to Influenza Infection
In mice treated with D-4F, peak IL-6 levels in lungs 7 days after inoculation were half those of control mice (Figure 2A). D-4F treatment suppressed plasma IL-6 concentrations at all time points measured (Figure 2B). Neither IgG nor IgM antibodies to D-4F were detected (data not shown).
|
D-4F Treatment Alters LDL and HDL During Influenza Infection
The acute-phase response includes alterations of plasma lipoproteins.21,22 D-4F treatment significantly inhibited the increase in LDL cholesterol observed 9 days after inoculation (Figure 3, left). HDL cholesterol (Figure 3, right) dropped in control mice after influenza infection, reaching a nadir 7 days after inoculation before returning toward baseline at 9 days. Treatment of mice with D-4F resulted in an increase in HDL cholesterol above preinfection levels at all time points. The alteration in paraoxonase activity observed during influenza infection followed a pattern similar to that for HDL cholesterol (Figure 4). Monocyte chemotactic activity induced by LDL in a human artery wall cell coculture was inhibited if cells were coincubated with HDL isolated from mice before influenza infection (Figure 5, day 0). By 2 days after inoculation, however, HDL from control mice significantly enhanced the LDL-induced monocyte chemotactic activity. In contrast, if mice were treated with D-4F, HDL remained nearly as effective as HDL from mice not exposed to influenza in suppressing LDL-induced monocyte chemotactic activity.
|
|
|
D-4F Inhibits Influenza-Induced Macrophage Trafficking Into the Aortic Arch and Innominate Arteries of Mice
Female mice were injected with male macrophages, and the uniquely male gene Sry was used to measure the arterial association of Sry DNA as an indicator of macrophage recruitment into the artery wall.10 As demonstrated in Figure 6A, and as Patel et al9 had shown previously, macrophages were very effective in homing to arteries of hypercholesterolemic mice. Compared with C57BL/6J mice on a chow diet, LDL receptornull mice on a Western diet showed a 3-fold increase in macrophage recruitment into the aortic arch and innominate artery. Consistent with the findings of Kim et al,10 injection of tumor necrosis factor-
and IL-6 at 30 minutes after the injection of donor macrophages resulted in a 25-fold increase in macrophage recruitment into the aortic arch and innominate arteries (Figure 6A). Figure 6B demonstrates that influenza infection in control mice resulted in a marked and progressive increase in Sry DNA in the aortic arch and innominate arteries (left), which was not seen in mice treated with D-4F (right).
|
D-4F Has Antiviral Activity
Based on previous studies in vitro,23,24 we measured viral titers in lungs from PBS- or D-4Ftreated mice before and at 2, 3, 5, 7, and 9 days after inoculation (Figure 7). As had been seen previously in wild-type C57BL/6J mice on a chow diet,4 peak viral titers were achieved 3 days after inoculation and then decreased, returning toward baseline by 9 days. In mice treated with D-4F, viral titers were reduced by >50% compared with controls at all time points.
|
D-4F Alters the Contact-Mediated Activation of Monocytes by T Cells
IL-6 is a proinflammatory cytokine and is strongly induced in monocytes after direct contact with stimulated T lymphocytes. IL-10 is a potent inhibitor of monocyte/macrophage function, suppressing production of many proinflammatory cytokines.25 Hyka and colleagues26 reported that human serum contained an inhibitory activity for the contact-mediated activation of monocytes by stimulated T cells. This inhibitory activity was found to be caused by apoA-I. To determine whether D-4F might be acting similarly to apoA-I, freshly isolated human monocytes were incubated for 48 hours with activated T cells in the absence or presence of increasing concentrations of D-4F, and the release of IL-6 and IL-10 into the medium was measured (Figure 8). As shown in Figure 8A, direct contact of monocytes with activated T cells resulted in a marked increase in IL-6 released into the tissue culture medium, which was inhibited in the presence of D-4F. In contrast, D-4F had a stimulatory effect on IL-10 release under the same conditions (Figure 8B). Sugiyama and coworkers27 demonstrated that GM-CSF is a potent endogenous mediator during monocyte/macrophage activation and differentiation. Figure 8C shows that D-4F, in addition to inhibiting IL-6 release, was shown to inhibit the contact-mediated release by monocytes of GM-CSF. No inhibition was observed when a scrambled peptide to D-4F was used at the same concentration (Figure 8C).
|
| Discussion |
|---|
|
|
|---|
| Acknowledgments |
|---|
| Footnotes |
|---|
Dr Anantharamaiah, Susan Hama, Dr Navab, and Dr Fogelman are principals in Bruin Pharma, a start-up biotech company.
Received June 14, 2002; revision received July 8, 2002; accepted July 8, 2002.
| References |
|---|
|
|
|---|
and interleukin-1ß. Arterioscler Thromb Vasc Biol. 2000; 20: 19761982.This article has been cited by other articles:
![]() |
E. M. deGoma, R. L. deGoma, and D. J. Rader Beyond high-density lipoprotein cholesterol levels evaluating high-density lipoprotein function as influenced by novel therapeutic approaches. J. Am. Coll. Cardiol., June 10, 2008; 51(23): 2199 - 2211. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. T. Bloedon, R. Dunbar, D. Duffy, P. Pinell-Salles, R. Norris, B. J. DeGroot, R. Movva, M. Navab, A. M. Fogelman, and D. J. Rader Safety, pharmacokinetics, and pharmacodynamics of oral apoA-I mimetic peptide D-4F in high-risk cardiovascular patients J. Lipid Res., June 1, 2008; 49(6): 1344 - 1352. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Ciszewski, Z. T. Bilinska, L. B. Brydak, C. Kepka, M. Kruk, M. Romanowska, E. Ksiezycka, J. Przyluski, W. Piotrowski, R. Maczynska, et al. Influenza vaccination in secondary prevention from coronary ischaemic events in coronary artery disease: FLUCAD study Eur. Heart J., June 1, 2008; 29(11): 1350 - 1358. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Movva and D. J. Rader Laboratory Assessment of HDL Heterogeneity and Function Clin. Chem., May 1, 2008; 54(5): 788 - 800. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Van Lenten, A. C. Wagner, M. Navab, G. M. Anantharamaiah, S. Hama, S. T. Reddy, and A. M. Fogelman Lipoprotein inflammatory properties and serum amyloid A levels but not cholesterol levels predict lesion area in cholesterol-fed rabbits J. Lipid Res., November 1, 2007; 48(11): 2344 - 2353. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Weihrauch, H. Xu, Y. Shi, J. Wang, J. Brien, D. W. Jones, S. Kaul, R. A. Komorowski, M. E. Csuka, K. T. Oldham, et al. Effects of D-4F on vasodilation, oxidative stress, angiostatin, myocardial inflammation, and angiogenic potential in tight-skin mice Am J Physiol Heart Circ Physiol, September 1, 2007; 293(3): H1432 - H1441. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. M. Buga, J. S. Frank, G. A. Mottino, M. Hendizadeh, A. Hakhamian, J. H. Tillisch, S. T. Reddy, M. Navab, G. M. Anantharamaiah, L. J. Ignarro, et al. D-4F decreases brain arteriole inflammation and improves cognitive performance in LDL receptor-null mice on a Western diet J. Lipid Res., October 1, 2006; 47(10): 2148 - 2160. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Navab, G.M. Anantharamaiah, and A. M. Fogelman An Apolipoprotein A-I Mimetic Works Best in the Presence of Apolipoprotein A-I Circ. Res., November 25, 2005; 97(11): 1085 - 1086. [Full Text] [PDF] |
||||
![]() |
M. Navab, G.M. Anantharamaiah, S. T. Reddy, B. J. Van Lenten, A. C. Wagner, S. Hama, G. Hough, E. Bachini, D. W. Garber, V. K. Mishra, et al. An Oral ApoJ Peptide Renders HDL Antiinflammatory in Mice and Monkeys and Dramatically Reduces Atherosclerosis in Apolipoprotein E-Null Mice Arterioscler. Thromb. Vasc. Biol., September 1, 2005; 25(9): 1932 - 1937. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Gupta, L. Dai, G. Datta, D. W. Garber, H. Grenett, Y. Li, V. Mishra, M. N. Palgunachari, S. Handattu, S. H. Gianturco, et al. Inhibition of Lipopolysaccharide-Induced Inflammatory Responses by an Apolipoprotein AI Mimetic Peptide Circ. Res., August 5, 2005; 97(3): 236 - 243. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Margeli, K. Skenderi, M. Tsironi, E. Hantzi, A.-L. Matalas, C. Vrettou, E. Kanavakis, G. Chrousos, and I. Papassotiriou Dramatic Elevations of Interleukin-6 and Acute-Phase Reactants in Athletes Participating in the Ultradistance Foot Race Spartathlon: Severe Systemic Inflammation and Lipid and Lipoprotein Changes in Protracted Exercise J. Clin. Endocrinol. Metab., July 1, 2005; 90(7): 3914 - 3918. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Navab, G.M. Anantharamaiah, S. Hama, G. Hough, S. T. Reddy, J. S. Frank, D. W. Garber, S. Handattu, and A. M. Fogelman D-4F and Statins Synergize to Render HDL Antiinflammatory in Mice and Monkeys and Cause Lesion Regression in Old Apolipoprotein E-Null Mice Arterioscler. Thromb. Vasc. Biol., July 1, 2005; 25(7): 1426 - 1432. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Van Lenten, A. C. Wagner, M. Navab, G.M. Anantharamaiah, E. K.-W. Hui, D. P. Nayak, and A. M. Fogelman D-4F, an Apolipoprotein A-I Mimetic Peptide, Inhibits the Inflammatory Response Induced by Influenza A Infection of Human Type II Pneumocytes Circulation, November 16, 2004; 110(20): 3252 - 3258. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. J. Barter, S. Nicholls, K.-A. Rye, G.M. Anantharamaiah, M. Navab, and A. M. Fogelman Antiinflammatory Properties of HDL Circ. Res., October 15, 2004; 95(8): 764 - 772. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Li, K.-Y. Chyu, J. R. F. Neto, J. Yano, N. Nathwani, C. Ferreira, P. C. Dimayuga, B. Cercek, S. Kaul, and P. K. Shah Differential Effects of Apolipoprotein A-I-Mimetic Peptide on Evolving and Established Atherosclerosis in Apolipoprotein E-Null Mice Circulation, September 21, 2004; 110(12): 1701 - 1705. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. V. Bocharov, I. N. Baranova, T. G. Vishnyakova, A. T. Remaley, G. Csako, F. Thomas, A. P. Patterson, and T. L. Eggerman Targeting of Scavenger Receptor Class B Type I by Synthetic Amphipathic {alpha}-Helical-containing Peptides Blocks Lipopolysaccharide (LPS) Uptake and LPS-induced Pro-inflammatory Cytokine Responses in THP-1 Monocyte Cells J. Biol. Chem., August 20, 2004; 279(34): 36072 - 36082. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Navab, G.M. Anantharamaiah, S. T. Reddy, S. Hama, G. Hough, V. R. Grijalva, A. C. Wagner, J. S. Frank, G. Datta, D. Garber, et al. Oral D-4F Causes Formation of Pre-{beta} High-Density Lipoprotein and Improves High-Density Lipoprotein-Mediated Cholesterol Efflux and Reverse Cholesterol Transport From Macrophages in Apolipoprotein E-Null Mice Circulation, June 29, 2004; 109(25): 3215 - 3220. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Datta, R. F. Epand, R. M. Epand, M. Chaddha, M. A. Kirksey, D. W. Garber, S. Lund-Katz, M. C. Phillips, S. Hama, M. Navab, et al. Aromatic Residue Position on the Nonpolar Face of Class A Amphipathic Helical Peptides Determines Biological Activity J. Biol. Chem., June 18, 2004; 279(25): 26509 - 26517. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Navab, G. M. Ananthramaiah, S. T. Reddy, B. J. Van Lenten, B. J. Ansell, G. C. Fonarow, K. Vahabzadeh, S. Hama, G. Hough, N. Kamranpour, et al. Thematic review series: The Pathogenesis of Atherosclerosis The oxidation hypothesis of atherogenesis: the role of oxidized phospholipids and HDL J. Lipid Res., June 1, 2004; 45(6): 993 - 1007. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Madjid, M. Naghavi, S. Litovsky, and S. W. Casscells Influenza and Cardiovascular Disease: A New Opportunity for Prevention and the Need for Further Studies Circulation, December 2, 2003; 108(22): 2730 - 2736. [Full Text] [PDF] |
||||
![]() |
B. J. Ansell, M. Navab, S. Hama, N. Kamranpour, G. Fonarow, G. Hough, S. Rahmani, R. Mottahedeh, R. Dave, S. T. Reddy, et al. Inflammatory/Antiinflammatory Properties of High-Density Lipoprotein Distinguish Patients From Control Subjects Better Than High-Density Lipoprotein Cholesterol Levels and Are Favorably Affected by Simvastatin Treatment Circulation, December 2, 2003; 108(22): 2751 - 2756. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Navab, S. Hama, G. Hough, and A. M. Fogelman Oral Synthetic Phospholipid (DMPC) Raises High-Density Lipoprotein Cholesterol Levels, Improves High-Density Lipoprotein Function, and Markedly Reduces Atherosclerosis in Apolipoprotein E-Null Mice Circulation, October 7, 2003; 108(14): 1735 - 1739. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Calabresi, M. Gomaraschi, and G. Franceschini Endothelial Protection by High-Density Lipoproteins: From Bench to Bedside Arterioscler. Thromb. Vasc. Biol., October 1, 2003; 23(10): 1724 - 1731. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Ou, Z. Ou, D. W. Jones, S. Holzhauer, O. A. Hatoum, A. W. Ackerman, D. W. Weihrauch, D. D. Gutterman, K. Guice, K. T. Oldham, et al. L-4F, an Apolipoprotein A-1 Mimetic, Dramatically Improves Vasodilation in Hypercholesterolemia and Sickle Cell Disease Circulation, May 13, 2003; 107(18): 2337 - 2341. [Abstract] [Full Text] [PDF] |
||||