MOLECULAR PATHOGENESIS-Induction of a Potential Paracrine Angiogenic Loop between Human THP-1 Macrophages and Human Microvascular Endothelial Cells during Bartonella henselae Infection

摘要: Bartonella henselae is responsible for various disease syndromes that loosely correlate with the immune status of the host. In the immunocompromised individual, B. henselae-induced angiogenesis, or bacillary angiomatosis, is characterized by vascular proliferative lesions similar to those in Kaposi's sarcoma. We hypothesize that B. henselae-mediated interaction with immune cells, namely, macrophages, induces potential angiogenic growth factors and cytokines which contribute in a paracrine manner to the proliferation of endothelial cells. Vascular endothelial growth factor (VEGF), a direct inducer of angiogenesis, and interleukin-1beta (IL-1beta), a potentiator of VEGF, were detected within 12 and 6 h, respectively, in supernatants from phorbol 12-myristate 13-acetate-differentiated human THP-1 macrophages exposed to live B. henselae. Pretreatment of macrophages with cytochalasin D, a phagocytosis …