It has been more than 30 years since the initial trials of Cyclosporin A to treat patients with new onset Type 1 diabetes (T1D). Since that time, there have been insights into genetic predisposition to the disease, the failures of immune tolerance, and mechanisms that cause the immune mediated β cell destruction. The genetic loci associated affect lymphocyte development and tolerance mechanisms.
View Article and Find Full Text PDFType 1 diabetes mellitus is caused by the killing of insulin-producing β cells by CD8+T cells. The disease progression, which is chronic, does not follow a course like responses to conventional antigens such as viruses, but accelerates as glucose tolerance deteriorates. To identify the unique features of the autoimmune effectors that may explain this behavior, we analyzed diabetogenic CD8+ T cells that recognize a peptide from the diabetes antigen IGRP (NRP-V7-reactive) in prediabetic NOD mice and compared them to others that shared their phenotype (CD44(+)CD62L(lo)PD-1(+)CXCR3(+)) but negative for diabetes antigen tetramers and to LCMV (lymphocytic choriomeningitis)-reactive CD8+ T cells.
View Article and Find Full Text PDFDogs are susceptible to different tickborne infections, including members of the Anaplasmataceae (Ehrlichia canis, E. ewingii, E. chaffeensis, Anaplasma phagocytophilum, A.
View Article and Find Full Text PDFHuman granulocytic anaplasmosis (HGA), caused by the granulocytic rickettsia-like organism Anaplasma phagocytophilum, is the 3rd most frequent vector-borne infection in North America. To understand the disease mechanisms of HGA, we developed a murine model that lacks clinical disease yet exhibits characteristic histopathologic and immunologic changes. Because the degree of hepatic histopathology is unrelated to high bacterial numbers, tissue injury in HGA is thought to occur due to products of innate immunity, such as nitric oxide (NO) and reactive nitrogen species (RNS) from cytokine-activated macrophages.
View Article and Find Full Text PDFHuman granulocytic anaplasmosis is a tickborne rickettsial infection of neutrophils caused by Anaplasma phagocytophilum. The human disease was first identified in 1990, although the pathogen was defined as a veterinary agent in 1932. Since 1990, US cases have markedly increased, and infections are now recognized in Europe.
View Article and Find Full Text PDFAnaplasma phagocytophilum is a tick-transmitted obligate intracellular bacterium of neutrophils that causes human granulocytic anaplasmosis. Previous data confirm that in vitro infection by A. phagocytophilum modifies neutrophil functions, including a 50% or greater reduction in phagocytosis and shedding of neutrophil cell surface adhesion molecule receptors.
View Article and Find Full Text PDFAnaplasma phagocytophilum infection induces functional neutrophil changes. Using both Candida albicans and fluorescent-aggregate phagocytosis assays, we examined whether neutrophil and dimethyl sulfoxide-differentiated HL-60 cell infection impairs internalization. A.
View Article and Find Full Text PDF