Plants use pattern recognition receptors to defend themselves from microbial pathogens. These receptors recognize pathogen-associated molecular patterns (PAMPs) and activate signaling pathways that lead to immunity. In rice (Oryza sativa), the chitin elicitor binding protein (CEBiP) recognizes chitin oligosaccharides released from the cell walls of fungal pathogens. Here, we show that the rice ...

Tumor immunity requires the participation of lymphocyte effector cells that display powerful processes to destroy malignant cells. Natural killer (NK) cells and CTLs, once activated, use the same lytic processes for mediating target cell death. However, they are triggered through distinctly separate antigen receptors. NK cells are currently known to express at least three families of receptors ...

The relevance of specific Abs for the induction of cellular effector functions against Bordetella pertussis was studied. IgG-opsonized B. pertussis was efficiently phagocytosed by human polymorphonuclear leukocytes (PMN). This process was mediated by the PMN IgG receptors, FcgammaRIIa (CD32) and FcgammaRIIIb (CD16), working synergistically. Furthermore, these FcgammaR triggered efficient PMN re...

Pathogen-associated molecular patterns (PAMPs) trigger plant defenses when perceived by surface-localized immune receptors. PAMP-triggered immunity (PTI) plays a vital role in the resistance of plants to numerous potential pathogens. MicroRNA (miRNA) biogenesis is known to be important for PTI, but miRNA species involved in this process have not been fully explored. Here we show that the Arabid...

Even though the microevolution of plant hosts and pathogens has been intensely studied, knowledge regarding macro-evolutionary patterns is limited. Having the highest species diversity and host-specificity among Oomycetes, downy mildews are a useful a model for investigating long-term host-pathogen coevolution. We show that phylogenies of Bremia and Asteraceae are significantly congruent. The a...

Plasmacytoid dendritic cells (pDCs) are characterized as type I interferon-producing cells that engage endosomal toll-like receptors (TLRs) and exclusively express sialic acid binding Ig-like lectin (Siglec)-H. However, their role in vivo remains unclear. Here we report a critical role for pDCs in the regulation of inflammation and T cell immunity in vivo by using gene-targeted mice with a defi...

Distinct cytotoxic agents currently used in the oncological armamentarium mediate their clinical benefit by influencing, directly or indirectly, the immune system in such a way that innate and adaptive immunity contributes to the tumoricidal activity. Now, we bring up evidence that both arms of anticancer immunity can be triggered through the intervention of the intestinal microbiota. Alkylatin...

Nucleotide binding leucine-rich repeat proteins (NLRs) are the major class of intracellular immune receptors in plants. NLRs typically function to specifically recognize pathogen effectors and to initiate and control defense responses that severely limit pathogen growth in plants (termed effector-triggered immunity, or ETI). Despite numerous reports supporting a central role in innate immunity,...

The Gram-negative bacterium Xanthomonas euvesicatoria (Xe) is the causal agent of bacterial spot disease of pepper and tomato. Xe delivers effector proteins into host cells through the type III secretion system to promote disease. Here, we show that the Xe effector XopAU, which is conserved in numerous Xanthomonas species, is a catalytically active protein kinase and contributes to the developm...