Laboratory of Molecular Biology

About: Laboratory of Molecular Biology is a facility organization based out in Cambridge, Cambridgeshire, United Kingdom. It is known for research contribution in the topics: Gene & RNA. The organization has 19395 authors who have published 24236 publications receiving 2101480 citations.

Binding activities of a repertoire of single immunoglobulin variable domains secreted from Escherichia coli

Abstract: IN antibodies, a heavy and a light chain variable domain, VH and VL, respectively, pack together and the hypervariable loops on each domain contribute to binding antigen1–4. We find, however, that isolated VH domains with good antigen-binding affinities can also be prepared. Using the polymerase chain reaction5, diverse libraries of VH genes were cloned from the spleen genomic DNA of mice immunized with either lysozyme or keyhole-limpet haemocyanin. From these libraries, VH domains were expressed and secreted from Escherichia coli. Binding activities were detected against both antigens, and two VH domains were characterized with affinities for lysozyme in the 20 nM range. Isolated variable domains may offer an alternative to monoclonal antibodies and serve as the key to building high-affinity human antibodies. We suggest the name 'single domain antibodies (dAbs)' for these antigen binding demands.

Nuocytes represent a new innate effector leukocyte that mediates type-2 immunity

Abstract: Innate immunity provides the first line of defence against invading pathogens and provides important cues for the development of adaptive immunity. Type-2 immunity-responsible for protective immune responses to helminth parasites and the underlying cause of the pathogenesis of allergic asthma-consists of responses dominated by the cardinal type-2 cytokines interleukin (IL)4, IL5 and IL13 (ref. 5). T cells are an important source of these cytokines in adaptive immune responses, but the innate cell sources remain to be comprehensively determined. Here, through the use of novel Il13-eGFP reporter mice, we present the identification and functional characterization of a new innate type-2 immune effector leukocyte that we have named the nuocyte. Nuocytes expand in vivo in response to the type-2-inducing cytokines IL25 and IL33, and represent the predominant early source of IL13 during helminth infection with Nippostrongylus brasiliensis. In the combined absence of IL25 and IL33 signalling, nuocytes fail to expand, resulting in a severe defect in worm expulsion that is rescued by the adoptive transfer of in vitro cultured wild-type, but not IL13-deficient, nuocytes. Thus, nuocytes represent a critically important innate effector cell in type-2 immunity.

Movement of Bax from the Cytosol to Mitochondria during Apoptosis

Abstract: Bax, a member of the Bcl-2 protein family, accelerates apoptosis by an unknown mechanism. Bax has been recently reported to be an integral membrane protein associated with organelles or bound to organelles by Bcl-2 or a soluble protein found in the cytosol. To explore Bcl-2 family member localization in living cells, the green fluorescent protein (GFP) was fused to the NH2 termini of Bax, Bcl-2, and Bcl-XL. Confocal microscopy performed on living Cos-7 kidney epithelial cells and L929 fibroblasts revealed that GFP–Bcl-2 and GFP–Bcl-XL had a punctate distribution and colocalized with a mitochondrial marker, whereas GFP–Bax was found diffusely throughout the cytosol. Photobleaching analysis confirmed that GFP–Bax is a soluble protein, in contrast to organelle-bound GFP–Bcl-2. The diffuse localization of GFP–Bax did not change with coexpression of high levels of Bcl-2 or Bcl-XL. However, upon induction of apoptosis, GFP–Bax moved intracellularly to a punctate distribution that partially colocalized with mitochondria. Once initiated, this Bax movement was complete within 30 min, before cellular shrinkage or nuclear condensation. Removal of a COOH-terminal hydrophobic domain from GFP–Bax inhibited redistribution during apoptosis and inhibited the death-promoting activity of both Bax and GFP– Bax. These results demonstrate that in cells undergoing apoptosis, an early, dramatic change occurs in the intracellular localization of Bax, and this redistribution of soluble Bax to organelles appears important for Bax to promote cell death.

A Century of Alzheimer's Disease

Abstract: One hundred years ago a small group of psychiatrists described the abnormal protein deposits in the brain that define the most common neurodegenerative diseases Over the past 25 years, it has become clear that the proteins forming the deposits are central to the disease process Amyloid-β and tau make up the plaques and tangles of Alzheimer's disease, where these normally soluble proteins assemble into amyloid-like filaments Tau inclusions are also found in a number of related disorders Genetic studies have shown that dysfunction of amyloid-β or tau is sufficient to cause dementia The ongoing molecular dissection of the neurodegenerative pathways is expected to lead to a true understanding of disease pathogenesis