scholarly journals Molecular Characterization of the Rhesus Rhadinovirus (RRV) ORF4 Gene and the RRV Complement Control Protein It Encodes

2007 ◽  
Vol 81 (8) ◽  
pp. 4166-4176 ◽  
Author(s):  
Linda Mark ◽  
O. Brad Spiller ◽  
Marcin Okroj ◽  
Simon Chanas ◽  
Jim A. Aitken ◽  
...  
Keyword(s):  
Complement Activation ◽  
Biological Significance ◽  
Full Length ◽  
In Vivo Model ◽  
Primate Model ◽  
Complement Control Protein ◽  
Functional Studies ◽  
Alternatively Spliced ◽  
Control Protein

ABSTRACT The diversity of viral strategies to modulate complement activation indicates that this component of the immune system has significant antiviral potential. One example is the Kaposi's sarcoma-associated herpesvirus (KSHV) complement control protein (KCP), which inhibits progression of the complement cascade. Rhesus rhadinovirus (RRV), like KSHV, is a member of the subfamily Gammaherpesvirinae and currently provides the only in vivo model of KSHV pathobiology in primates. In the present study, we characterized the KCP homologue encoded by RRV, RRV complement control protein (RCP). Two strains of RRV have been sequenced to date (H26-95 and 17577), and the RCPs they encode differ substantially in structure: RCP from strain H26-95 has four complement control protein (CCP) domains, whereas RCP from strain 17577 has eight CCP domains. Transcriptional analyses of the RCP gene (ORF4, referred to herein as RCP) in infected rhesus macaque fibroblasts mapped the ends of the transcripts of both strains. They revealed that H26-95 encodes a full-length, unspliced RCP transcript, while 17577 RCP generates a full-length unspliced mRNA and two alternatively spliced transcripts. Western blotting confirmed that infected cells express RCP, and immune electron microscopy disclosed this protein on the surface of RRV virions. Functional studies of RCP encoded by both RRV strains revealed their ability to suppress complement activation by the classical (antibody-mediated) pathway. These data provide the foundation for studies into the biological significance of gammaherpesvirus complement regulatory proteins in a tractable, non-human primate model.

Properdin binding independent of complement activation in an in vivo model of anti-GBM disease

2018 ◽  
Vol 102 ◽  
pp. 176
Author(s):  
Juha Kotimaa ◽  
Joseph O’Flynn ◽  
Ria Faber-Krol ◽  
Karin Koekkoek ◽  
Ngaisah Klar-Mohamad ◽  
...  
Keyword(s):  
Complement Activation ◽  
In Vivo Model

scholarly journals Rab27a Is an Essential Component of Melanosome Receptor for Myosin Va

2002 ◽  
Vol 13 (5) ◽  
pp. 1735-1749 ◽  
Author(s):  
Xufeng Wu ◽  
Fei Wang ◽  
Kang Rao ◽  
James R. Sellers ◽  
John A. Hammer
Keyword(s):  
Full Length ◽  
Tail Domain ◽  
Wild Type ◽  
Essential Component ◽  
Myosin Va ◽  
Alternatively Spliced ◽  
Additional Protein ◽  
The Brain ◽  
Alternatively Spliced Exons

Melanocytes that lack the GTPase Rab27a (ashen) are disabled in myosin Va-dependent melanosome capture because the association of the myosin with the melanosome surface depends on the presence of this resident melanosomal membrane protein. One interpretation of these observations is that Rab27a functions wholly or in part as the melanosome receptor for myosin Va (Myo5a). Herein, we show that the ability of the myosin Va tail domain to localize to the melanosome and generate a myosin Va null (dilute) phenotype in wild-type melanocytes is absolutely dependent on the presence of exon F, one of two alternatively spliced exons present in the tail of the melanocyte-spliced isoform of myosin Va but not the brain-spliced isoform. Exon D, the other melanocyte-specific tail exon, is not required. Similarly, the ability of full-length myosin Va to colocalize with melanosomes and to rescue their distribution indilute melanocytes requires exon F but not exon D. These results predict that an interaction between myosin Va and Rab27a should be exon F dependent. Consistent with this, Rab27a present in detergent lysates of melanocytes binds to beads coated with purified, full-length melanocyte myosin Va and melanocyte myosin Va lacking exon D, but not to beads coated with melanocyte myosin Va lacking exon F or brain myosin Va. Moreover, the preparation of melanocyte lysates in the presence of GDP rather than guanosine-5′-O-(3-thio)triphosphate reduces the amount of Rab27a bound to melanocyte myosin Va-coated beads by approximately fourfold. Finally, pure Rab27a does not bind to myosin Va-coated beads, suggesting that these two proteins interact indirectly. Together, these results argue that Rab27a is an essential component of a protein complex that serves as the melanosome receptor for myosin Va, suggest that this complex contains at least one additional protein capable of bridging the indirect interaction between Rab27a and myosin Va, and imply that the recruitment of myosin Va to the melanosome surface in vivo should be regulated by factors controlling the nucleotide state of Rab27a.

Review: Gp-340/DMBT1 in mucosal innate immunity

2010 ◽  
Vol 16 (3) ◽  
pp. 160-167 ◽  
Author(s):  
Jens Madsen ◽  
Jan Mollenhauer ◽  
Uffe Holmskov
Keyword(s):  
Innate Immunity ◽  
Influenza A ◽  
Research Field ◽  
Secretory Iga ◽  
Functional Studies ◽  
Gram Positive Bacteria ◽  
Alternatively Spliced ◽  
Trefoil Factor 2

Deleted in Malignant Brain Tumour 1 (DMBT1) is a gene that encodes alternatively spliced proteins involved in mucosal innate immunity. It also encodes a glycoprotein with a molecular mass of 340 kDa, and is referred to as gp-340 (DMBT1gp340) and salivary agglutinin (DMBT1SAG). DMBT1gp340 is secreted into broncho-alveolar surface lining fluid whereas DMBTSAG is present in the saliva. The two molecules were shown to be identical and both interact with and agglutinate several Gram-negative and Gram-positive bacteria including Streptococcus mutans, a bacterium responsible for caries in the oral cavity. DMBT1gp340 interacts with surfactant proteins A and D (SP-D). DMBT1gp340 and SP-D can individually and together interact and agglutinate influenza A virus. DMBT1gp340 also binds to HIV-1 and facilitates transcytosis of the virus into epithelial cells. DMBT1 binds to a variety of other host proteins, including serum and secretory IgA, C1q, lactoferrin, MUC5B and trefoil factor 2 (TFF2), all molecules with involvement in innate immunity and/or wound-healing processes. Recent generation of Dmbt1-deficient mice has provided the research field of DMBT1 with a model that allows research to progress from in vitro studies to in vivo functional studies of the multifunctional proteins encoded by the DMBT1 gene.

scholarly journals The leukocyte non-coding RNA landscape in critically ill patients with sepsis

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Brendon P Scicluna ◽  
Fabrice Uhel ◽  
Lonneke A van Vught ◽  
Maryse A Wiewel ◽  
Arie J Hoogendijk ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Host Response ◽  
In Vivo Model ◽  
Human Endotoxemia ◽  
Functional Studies ◽  
Protein Levels ◽  
Non Coding Rna ◽  
Blood Leukocyte ◽  
Long Non Coding Rna

The extent of non-coding RNA alterations in patients with sepsis and their relationship to clinical characteristics, soluble mediators of the host response to infection, as well as an advocated in vivo model of acute systemic inflammation is unknown. Here we obtained whole blood from 156 patients with sepsis and 82 healthy subjects among whom eight were challenged with lipopolysaccharide in a clinically controlled setting (human endotoxemia). Via next-generation microarray analysis of leukocyte RNA we found that long non-coding RNA and, to a lesser extent, small non-coding RNA were significantly altered in sepsis relative to health. Long non-coding RNA expression, but not small non-coding RNA, was largely recapitulated in human endotoxemia. Integrating RNA profiles and plasma protein levels revealed known as well as previously unobserved pathways, including non-sensory olfactory receptor activity. We provide a benchmark dissection of the blood leukocyte ‘regulome’ that can facilitate prioritization of future functional studies.

scholarly journals A helminth-derived suppressor of ST2 blocks allergic responses

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Francesco Vacca ◽  
Caroline Chauché ◽  
Abhishek Jamwal ◽  
Elizabeth C Hinchy ◽  
Graham Heieis ◽  
...  
Keyword(s):  
Immune Responses ◽  
Heligmosomoides Polygyrus ◽  
Human Pbmc ◽  
Complement Control Protein ◽  
High Affinity ◽  
Intestinal Nematode ◽  
Control Protein

The IL-33-ST2 pathway is an important initiator of type 2 immune responses. We previously characterised the HpARI protein secreted by the model intestinal nematode Heligmosomoides polygyrus, which binds and blocks IL-33. Here, we identify H. polygyrus Binds Alarmin Receptor and Inhibits (HpBARI) and HpBARI_Hom2, both of which consist of complement control protein (CCP) domains, similarly to the immunomodulatory HpARI and Hp-TGM proteins. HpBARI binds murine ST2, inhibiting cell surface detection of ST2, preventing IL-33-ST2 interactions, and inhibiting IL-33 responses in vitro and in an in vivo mouse model of asthma. In H. polygyrus infection, ST2 detection is abrogated in the peritoneal cavity and lung, consistent with systemic effects of HpBARI. HpBARI_Hom2 also binds human ST2 with high affinity, and effectively blocks human PBMC responses to IL-33. Thus, we show that H. polygyrus blocks the IL-33 pathway via both HpARI which blocks the cytokine, and also HpBARI which blocks the receptor.

scholarly journals Factor V turnover in a primate model

Blood ◽  
1995 ◽  
Vol 86 (7) ◽  
pp. 2616-2623 ◽  
Author(s):  
MD Rand ◽  
SR Hanson ◽  
KG Mann
Keyword(s):  
Specific Activity ◽  
Apparent Molecular Weight ◽  
In Vivo Model ◽  
Normal Male ◽  
Factor V ◽  
Primate Model ◽  
Isolation And Characterization ◽  
Plasma Factor ◽  
Thrombin Activation

The isolation and characterization of baboon plasma factor V (FV) were performed for the development of an in vivo model for studying factor V/Va physiology in nonhuman primates. Baboon FV was purified by immunoaffinity chromatography with an antihuman FV monoclonal antibody and exhibits a specific activity of 1,940 U/mg. Baboon FV activation by thrombin proceeds through two proteolytic pathways similar to those observed with human and bovine FV. Limited amino acid sequencing of FV and its thrombin activation fragments shows 95% identity with human and 79% identity with bovine FV. 125I-Factor V and a mixture of thrombin cleaved 125I-FV activation products were infused into normal male baboons and evaluated by blood sample radioactivity measurements and by autoradiography of plasma samples following resolution by gel electrophoresis. Factor V disappeared with a half-life (t1/2) of 12.98 +/- 1.85 hours and was cleared without obvious degradation of the molecule during circulation. The radioactivity associated with the thrombin activated FV mixture, which consisted of the Mr = 220,000 activation intermediate, the Mr = 150,000 activation peptide, the heavy chain (HC) and the light chain (LC) of FVa, was cleared in a nonlinear manner. The HC and LC were removed with t1/2 < 20 minutes. The apparent molecular weight (Mr) = 220,000 and Mr = 150,000 fragments were cleared with t1/2 > 6 hours and t1/2 > 30 hours, respectively.

Alternative 5' splice site selection induced by heat shock

1994 ◽  
Vol 14 (1) ◽  
pp. 567-575
Author(s):  
H Takechi ◽  
N Hosokawa ◽  
K Hirayoshi ◽  
K Nagata
Keyword(s):  
Alternative Splicing ◽  
Heat Shock ◽  
Site Selection ◽  
Donor Site ◽  
Splice Donor Site ◽  
In Vivo Model ◽  
Recognition Mechanism ◽  
Amino Acid Analog ◽  
Alternatively Spliced

The mouse HSP47 gene consists of six exons separated by five introns. Three HSP47 cDNAs differing only in their 5' noncoding regions have been reported. One of these alternatively spliced mRNAs was detected only after heat shock, which caused an alternative 5' splice donor site selection. Other stress inducers, including an amino acid analog and sodium arsenite, had no effect on the alternative splicing. The alternatively spliced mRNA, which was 169 nucleotides longer in the 5' noncoding region compared to mRNA transcribed in non-heat shock conditions, was efficiently translated under heat shock conditions. This novel finding that alternative splicing is caused by artificial treatment like heat shock will provide a useful in vivo model for understanding the exon-intron recognition mechanism as well as heat shock-induced alterations in gene expression.

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