Triacylated lipoproteins derived from Mycoplasma pneumoniae activate nuclear factor-κB through toll-like receptors 1 and 2

Pathogenesis of Mycoplasma pneumoniae infection is considered to be in part attributed to excessive immune responses. Recently, a mycoplasma lipoprotein has been shown to induce nuclear factor κB (NF-κB) activation through toll-like receptor 1 (TLR1), TLR2 and TLR6. In this study, we examined the ability of lipoproteins from M. pneumoniae to activate NF-κB through TLR1- and TLR2-dependent, but TLR6-independent, pathways, and the active components responsible for the NF-κB activation through the TLR6-independent pathway were identified. The active lipoproteins were found to be MPN611 and MPN162 of M. pneumoniae (designated N-ALP1 and N-ALP2, respectively). Purified N-ALP1 and N-ALP2 from M. pneumoniae and triacylated partial synthetic lipopeptides of N-ALP1 and N-ALP2 augmented the levels of NF-κB induction through TLR1- and TLR2-dependent pathways, whereas diacylated partial synthetic lipopeptides of N-ALP1 and N-ALP2 activated NF-κB through TLR1-, TLR2- and TLR6-dependent pathways. These data suggest that N-ALP1 and N-ALP2 would be triacylated lipoproteins. The activity of N-ALP1 and N-ALP2 was decreased with a pretreatment of lipoprotein lipase, and partially decreased by protease treatment, indicating that the lipid moiety of N-ALP1 and N-ALP2 is critical for the NF-κB activation. Thus, triacylated lipoproteins derived from M. pneumoniae might activate NF-κB through TLR1 and TLR2, but not TLR6

New Marsileaceous Fossils from the Late Cretaceous of South America and a Reevaluation of Marsileaceaephyllum.

Herein we report new macrofossils and associated microfossils representing the aquatic fern family Marsileaceae from the Campanian to Maastrichtian Cañadón del Irupé locality, La Colonia Formation, Chubut Province, Argentina. The macrofossils include compound leaves, detached leaflets, and sporocarps. The venation of the leaflets is consistent with the diagnosis of Marsileaceaephyllum, which we argue is poorly defined. Consequently, the circumscription and diagnosis of Marsileaceaephyllum are emended in order to limit the taxon to include only leaves or rhizomes bearing leaves with four leaflets that most resemble those of Marsilea among extant genera of Marsileaceae. The Cañadón del Irupé leaves and leaflets are assigned to the new genus Mirasolita, erected to encompass compound leaves bearing two petiolulate leaflets, each leaflet having a reniform lamina and reticulate venation. The architecture of Mirasolita leaves and leaflets is distinct from that of leaves of any of the living marsileaceous genera. The stalked sporocarps are assigned to the new genus Lugiomarsiglia. They are attributed to Marsileaceae because each has a sclerenchymatous wall surrounding circular bodies interpreted as sporangia. Associated megaspores are assigned to Molaspora lobata, a geographically widespread, primarily Late Cretaceous dispersed spore taxon. The co-occurrence of Molaspora lobata with an extinct marsileaceous leaf form fits a pattern wherein Cretaceous Regnellidium-like megaspores are associated with or found in situ within marsileaceous macrofossils that display a variety of morphologies.Fil: Hermsen, Elizabeth. Ohio State University; Estados Unidos de América;Fil: Gandolfo, Maria A.. Cornell University; Estados Unidos de América;Fil: Cuneo, Nestor Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontologico Egidio Feruglio; Argentin