Borrelia burgdorferi stimulation of chemokine secretion by cells of monocyte lineage in patients with Lyme arthritis

Introduction: Joint fluid in patients with Lyme arthritis often contains high levels of CCL4 and CCL2, which are chemoattractants for monocytes and some T cells, and CXCL9 and CXCL10, which are chemoattractants for CD4+ and CD8+ T effector cells. These chemokines are produced primarily by cells of monocyte lineage in TH1-type immune responses. Our goal was to begin to learn how infection with Borrelia burgdorferi leads to the secretion of these chemokines, using patient cell samples. We hypothesized that B. burgdorferi stimulates chemokine secretion from monocytes/macrophages in multiple ways, thereby linking innate and adaptive immune responses. Methods: Peripheral blood mononuclear cells (PBMC) from 24 Lyme arthritis patients were stimulated with B. burgdorferi, interferon (IFN)-γ, or both, and the levels of CCL4, CCL2, CXCL9 and CXCL10 were measured in culture supernatants. CD14+ monocytes/macrophages from PBMC and synovial fluid mononuclear cells (SFMC) were stimulated in the same way, using available samples. CXCR3, the receptor for CXCL9 and CXCL10, and CCR5, the receptor for CCL4, were assessed on T cells from PBMC and SFMC. Results: In patients with Lyme arthritis, B. burgdorferi but not IFN-γ induced PBMC to secrete CCL4 and CCL2, and B. burgdorferi and IFN-γ each stimulated the production of CXCL9 and CXCL10. However, with the CD14+ cell fraction, B. burgdorferi alone stimulated the secretion of CCL4; B. burgdorferi and IFN-γ together induced CCL2 secretion, and IFN-γ alone stimulated the secretion of CXCL9 and CXCL10. The percentage of T cells expressing CXCR3 or CCR5 was significantly greater in SFMC than PBMC, confirming that $T_H1$ effector cells were recruited to inflamed joints. However, when stimulated with B. burgdorferi or IFN-γ, SFMC and PBMC responded similarly. Conclusions: B. burgdorferi stimulates PBMC or CD14+ monocytes/macrophages directly to secrete CCL4, but spirochetal stimulation of other intermediate cells, which are present in PBMC, is required to induce CD14+ cells to secrete CCL2, CXCL9 and CXCL10. We conclude that B. burgdorferi stimulates monocytes/macrophages directly and indirectly to guide innate and adaptive immune responses in patients with Lyme arthritis

Borrelia burgdorferi Genetic Markers and Disseminated Disease in Patients with Early Lyme Disease

Three genetic markers of Borrelia burgdorferi have been associated with disseminated disease: the OspC type, the 16S-23S rRNA intergenic spacer type (RST), and vlsE. Here, we modified previous methods so as to identify the three markers by PCR and restriction fragment length polymorphism in parallel, analyzed B. burgdorferi isolates from erythema migrans (EM) skin lesions in 91 patients, and correlated the results with evidence of dissemination. OspC type A was found approximately twice as frequently in patients with disseminated disease, whereas type K was identified approximately twice as often in those without evidence of dissemination, but these trends were not statistically significant. The remaining seven types identified were found nearly equally in patients with or without evidence of dissemination. RST 1 strains were significantly associated with dissemination (P = 0.03), whereas RST 2 and RST 3 strains tended to have an inverse association with this outcome. The vlsE gene was identified in all 91 cases, using primer sets specific for an N-terminal sequence of B. burgdorferi strain B31 (vlsE(B31)) or strain 297 (vlsE(297)), but neither marker was associated with dissemination. Specific combinations of the three genetic markers usually occurred together. OspC type A was always found with RST 1 and vlsE(B31), type K was always identified with RST 2 and more often with vlsE(297), and types E and I were almost always found with RST 3 and equally often with vlsE(B31) and vlsE(297). We conclude that B. burgdorferi strains vary in their capacity to disseminate, but almost all strains isolated from EM lesions sometimes caused disseminated disease

Chemokine Signatures in the Skin Disorders of Lyme Borreliosis in Europe: Predominance of CXCL9 and CXCL10 in Erythema Migrans and Acrodermatitis and CXCL13 in Lymphocytoma▿

The three skin disorders of Lyme borreliosis in Europe include erythema migrans, an acute, self-limited lesion; borrelial lymphocytoma, a subacute lesion; and acrodermatitis chronica atrophicans, a chronic lesion. Using quantitative reverse transcription-PCR, we determined mRNA expression of selected chemokines, cytokines, and leukocyte markers in skin samples from 100 patients with erythema migrans, borrelial lymphocytoma, or acrodermatitis chronica atrophicans and from 25 control subjects. Chemokine patterns in lesional skin in each of the three skin disorders included low but significant mRNA levels of the neutrophil chemoattractant CXCL1 and the dendritic cell chemoattractant CCL20 and intermediate levels of the macrophage chemoattractant CCL2. Erythema migrans and particularly acrodermatitis lesions had high mRNA expression of the T-cell-active chemokines CXCL9 and CXCL10 and low levels of the B-cell-active chemokine CXCL13, whereas lymphocytoma lesions had high levels of CXCL13 and lower levels of CXCL9 and CXCL10. This pattern of chemokine expression was consistent with leukocyte marker mRNA in lesional skin. Moreover, using immunohistologic methods, CD3+ T cells and CXCL9 were visualized in erythema migrans and acrodermatitis lesions, and CD20+ B cells and CXCL13 were seen in lymphocytoma lesions. Thus, erythema migrans and acrodermatitis chronica atrophicans have high levels of the T-cell-active chemokines CXCL9 and CXCL10, whereas borrelial lymphocytoma has high levels of the B-cell-active chemokine CXCL13