blood fluke exploitation of non-cognate cd4+ t cell help to facilitate parasite development血吸虫开发non-cognate cd4 + t细胞有助于促进寄生虫的发展.pdfVIP

Blood Fluke Exploitation of Non-Cognate CD4+ T Cell Help to Facilitate Parasite Development 1 1 2 1 1 1 Erika W. Lamb , Colleen D. Walls , John T. Pesce , Diana K. Riner , Sean K. Maynard , Emily T. Crow , 2 1 1 Thomas A. Wynn , Brian C. Schaefer , Stephen J. Davies * 1 Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America, 2 Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America Abstract Schistosoma blood flukes, which infect over 200 million people globally, co-opt CD4+ T cell-dependent mechanisms to facilitate parasite development and egg excretion. The latter requires Th2 responses, while the mechanism underpinning the former has remained obscure. Using mice that are either defective in T cell receptor (TCR) signaling or that lack TCRs ¨ + that can respond to schistosomes, we show that naıve CD4 T cells facilitate schistosome development in the absence of T ¨ + cell receptor signaling. Concurrently, the presence of naıve CD4 T cells correlates with both steady-state changes in the expression of genes that are critical for the development of monocytes and macrophages and with significant changes in the composition of peripheral mononuclear phagocyte populations. Finally, we show that direct stimulation of the m