Potential role of monocyte chemoattractant protein 1/JE in monocyte/macrophage-dependent IgA immune complex alveolitis in the rat.
We have examined the role of monocyte chemoattractant protein 1 (MCP 1) in the pathogenesis of monocyte/macrophage-dependent IgA immune complex alveolitis in the rat. Rat MCP 1 was cloned and expressed in order to facilitate analysis of its function in rat models of human disease. A cDNA library was constructed from rat pulmonary artery endothelial cells stimulated with TNF-alpha. The cDNA library was screened with synthetic oligonucleotide probes based on the recently published rat MCP 1 cDNA sequence. Among numerous MCP 1-positive clones, four full length (approximately 480 bp) cDNA were rescued, amplified by polymerase chain reaction, and ligated into a pJVETLZ baculovirus transfer vector. Spodoptera frugiperda insect cells (Sf-21) infected with baculovirus recombinants (Auto-grapha california nuclear polyhedrosis virus) bearing properly oriented MCP 1 cDNA (AcMCP 1) directed the expression of unique peptides of 18, 21, and 23 kDa. Treatment of AcMCP 1-infected Sf-21 cells with tunicamycin resulted in reduced production of the 21- and 23-kDa proteins and an increase in 16- to 18-kDa products, the predicted size range of uncleaved and nonglycosylated rat MCP 1. Denatured and refolded 23-kDa and 21-kDa rat MCP 1 species exhibited dose-dependent monocyte-specific chemotactic activity at concentrations as low as 10(-10) M whereas the 18-kDa species exhibited negligible activity. Antibodies that react with the immunoblot, block rat rMCP 1-directed monocyte chemotaxis, and neutralize monocyte-specific chemotactic activity secreted by TNF-stimulated rat endothelial cells were raised in rabbits immunized with the 23-kDa MCP 1 species. Intravenous administration of anti-MCP 1 antibodies upon initiation of IgA immune complex lung injury resulted in a marked reduction in lung injury as measured by pulmonary vascular permeability, alveolar hemorrhage, and pulmonary monocyte/macrophage recruitment and pulmonary monocyte/macrophage recruitment. These data suggest that MCP 1 may play an important role in the pathogenesis of monocyte/macrophage-dependent IgA immune complex alveolitis in the rat.
Jones
M L
ML
Department of Pathology, University of Michigan Medical School, Ann Arbor 48109-0602.
Mulligan
M S
MS
Flory
C M
CM
Ward
P A
PA
Warren
J S
JS
D000818:Animals; D000936:Antigen-Antibody Complex; D001483:Base Sequence; D018932:Chemokine CCL2; D002630:Chemotactic Factors / Q000502:physiology*; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D007105:Immune Complex Diseases / Q000276:immunology*; D007070:Immunoglobulin A / Q000276:immunology; D007158:Immunologic Techniques; D008171:Lung Diseases / Q000276:immunology*; D008264:Macrophages / Q000276:immunology*; D008969:Molecular Sequence Data; D009000:Monocytes / Q000276:immunology*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D051381:Rats; D011994:Recombinant Proteins; D014415:Tunicamycin / Q000494:pharmacology
D000936:Antigen-Antibody Complex; D018932:Chemokine CCL2; D002630:Chemotactic Factors; D007070:Immunoglobulin A; D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; D014415:Tunicamycin; D004247:DNA