CCL4 and periodontitis: This is in agreement with our previous results showing that in addition to elevated serum antibody response to periodontal pathogens in periodontitis patients [29,30], purified A. actinomycetemcomitans components induced proatherogenic (foam cells) and/or proinflammatory (cytokines) responses from murine macrophages [31] as well as production of proinflammatory cytokines and chemokines (IL-6, IL-8, and MIP-1β) from human whole blood [17].