Kotaro Matsumoto

Rickettsia massiliae, strain Bar29, was detected in engorged female ticks of the Rhiphicephalus sanguineus group collected in Corsica, a French Mediterranean island. Ticks were identified by molecular analysis as Rhipicephalus turanicus (Pomerantsev) (Acari: Ixodidae). Twenty larvae of the second generation obtained from a R. massiliae-infected, engorged female were tested by polymerase chain reaction (PCR) and all were positive for R. massiliae. Larvae of the same cohort were fed on rabbits and

Neutrophils form neutrophil extracellular traps (NETs), which are involved in the pathogenesis of ANCA-associated vasculitis (AAV). Recent reports suggest that platelets stimulated via toll-like receptor (TLR) pathways can induce NETs formation. However, the mechanism underlying the involvement of platelets in NETs formation in AAV is unknown. We investigated the role of platelets in the pathogenesis of AAV. Platelets from AAV patients and healthy controls (HCs) were co-cultured with peripheral

Antigen-specific CD8+ T cells can destroy epithelium expressing HPV16 E7 tumor antigen, but presentation of E7 antigen from skin is insufficient to reactivate memory CD8+ T cells induced by immunotherapy. Thus, effective cancer immunotherapy in humans may need to invoke sufficient effector as well as memory T cells.

Deer keds (Lipoptena cervi) are thought to have been introduced into New England from Europe during the 1800 s. We sought to determine whether L. cervi from Massachusetts deer contained evidence of infection by Bartonella schoenbuchensis, which appears to be maintained by L. cervi in Europe. Five of 6 keds were found to contain B. schoenbuchensis DNA, and 2 deer ticks cofeeding on deer with such keds did as well. The detection of Bartonella DNA in deer ticks probably represents contamination by

Transplantation of bone marrow cells of lpr/lpr mice into irradiated normal mice fails to develop massive lymphadenopathy or autoimmunity but causes severe graft-vs.-host-like syndrome. To elucidate an abnormality of lpr/lpr bone marrow-derived T cells, we transplanted bone marrow cells of Mlsb lpr/lpr mice into H-2-compatible Mlsa non-lpr mice. Although lpr/lpr T cell precursors repopulated the host thymus as well as +/+ cells, a proportion of CD4+CD8+ cells decreased, and that of both CD4- and

Our results from peripheral immuno-phenotyping analysis indicate that the numbers of Th and Tfh cells changed along with the disease condition in both GCA and TAK, while that of CD8⁺ T cells did not, especially in TAK. Treatment with biologic agents decreased the proportion of Th and Tfh cells, but not CD8⁺ T cells, in the patients. Chronological immuno-phenotyping data explained the difference in therapeutic response, such as reactivities against biologics, between GCA and

Human skin grafted on to athymic nude mice (BALB/C-nu/nu) spontaneously hyperpigments. We wished to identify the morphological and molecular bases for the hyperpigmentation for this phenomenon. We present data on the relationship of healing, regeneration of melanocytes and production of some melanogenic stimuli. Biopsies were taken at preset times post-graft and studied by histological and immunohistochemical methods. DOPA-positive melanocytes first became visible 120 h post-graft and melanin de

Chronological changes in CD14⁺⁺ CD16⁺ intermediate monocyte counts can be a marker of disease relapse in AAV patients.

Patients with active AAV can be divided into three subgroups based on immuno-phenotyping. These results may provide a hint to understanding disease pathophysiology and prognosis, and determining appropriate treatment.

We collected a total of 206 Haemaphysalis longicornis ticks by flagging in pastures in Yonaguni Island, Okinawa, Japan, in April 2008. Four of the 206 tick DNA samples tested were positive in a polymerase chain reaction (PCR) screening for the 16SrRNA gene of Anaplasmataceae. Partial sequences of 4 PCR products were identical to each other. Longer sequences of the 16SrRNA gene were successfully determined in 2 of the 4 tick samples, and the obtained 1,392 bp and 1,300 bp sequences revealed high