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Davis AR Clements MK Bunger PL Siemsen DW Quinn MT 《Veterinary immunology and immunopathology》2000,74(3-4):285-301
GTPases of the Rho family play important roles in human leukocyte signal transduction pathways; however, little is known about the function of these proteins in bovine cells. In the present studies, we isolated molecular clones of bovine Rac1, Rac2, and the Rac/Rho GTPase regulatory protein D4-GDP dissociation inhibitor (D4-GDI) from a bovine bone marrow cDNA library. These clones contained complete open reading frames, encoding 192, 192, and 200 amino acids, respectively. Comparison of the bovine amino acid sequences with those of other species demonstrated a high degree of identity of these proteins across all species, suggesting that these proteins likely play conserved functional roles in bovine leukocyte signal transduction pathways. Comparative Western blotting of these proteins in human and bovine neutrophil cytosol demonstrated that Rac2 was the predominant Rac species and that D4-GDI was the predominant GDI species in bovine neutrophil cytosol. Despite the high degree of homology between human and bovine Rac2, some of the anti-peptide antibody probes prepared against human Rac2 failed to recognize the bovine homologue. We also showed by subcellular fractionation techniques that Rac2 is localized primarily to the cytosolic compartment of resting bovine neutrophils, but is translocated to the plasma membrane after stimulation with PMA. These findings suggest that Rac2 does play a role in bovine neutrophil activation. In addition, these data will be helpful in developing more specific probes for investigating the role of these proteins in bovine leukocyte signal transduction pathways and for studying various inflammatory diseases in cattle. 相似文献
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The receptor I for the Fc region of immunoglobulin G (Fc gamma RI) is a member of the Ig superfamily with a high affinity, and it mediates antibody-dependent cellular cytotoxicity and immune complex clearance. In this study, a cDNA encoding the bovine Fc gamma RI was cloned. The full-length cDNA sequence is 1050 bp long with a short 5'- and long 3'-untranslated end regions, which codes for 349 amino acids and contains a signal peptide, an extracellular region with three Ig-like domains, and transmembrane and intracytoplasmic domains. Five potential N-linked glycosylation sites are recognized in this sequence. Compared with the sequences of human and mouse Fc gamma RI, the homologies of nucleotide sequences are 80 and 69% and homologies of deduced amino acid sequences are 66 and 55%, respectively. It is shown that the sequences of the monomeric IgG binding domain in these three species of Fc gamma RI are highly conserved. 相似文献
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T W Jungi T Francey M Brcic B Pohl E Peterhans 《Veterinary immunology and immunopathology》1992,33(4):321-337
Ovine bone marrow-derived macrophages (BMM) may express several IgG receptor (Fc gamma receptor; FcR) subsets. To study this, model particles (opsonized erythrocytes; EA), which are selectively handled by certain FcR subsets of human macrophages were used in cross-inhibition studies and found to react in a similar manner with FcR subsets of sheep macrophages. In experiments with monoclonal antibodies against subsets of human FcR, human erythrocytes (E) treated with human anti-D-IgG (anti-D-EAhu) and sheep E treated with bovine IgG1 (Bo1-EAs) were handled selectively by human macrophage FcRI and FcRII, respectively. Rabbit-IgG-coated sheep E (Rb-EAs) were recognized by FcRI, FcRII and possibly also by FcRIII of human macrophages. Anti-D-EAhu, Bo1-EAs and Rb-EAs were also ingested by sheep BMM. Competitive inhibition tests, using various homologous and heterologous IgG isotypes as fluid phase inhibitors and the particles used as FcR-specific tools in man (anti-D-EAhu and Bo1-EAs), revealed a heterogeneity of FcR also in sheep BMM. Thus, ingestion of anti-D-EAhu by ovine BMM was inhibited by low concentrations of competitor IgG from rabbit or man in the fluid phase, but not at all by bovine IgG1, whereas ingestion of Bo1-EAs was inhibited by bovine IgG1. This suggested that anti-D-EAhu were recognized by a FcR subset distinct from that recognizing bovine-IgG1. It was concluded that sheep BMM express functional analogs of human macrophage FcRI and FcRII and that Bo1-EAs and anti-D-EAhu are handled by distinct subsets of BMM FcR. All EAhu tested (EAhu treated with anti-D, sheep IgG1 or sheep IgG2) were ingested to a lower degree than EAs. This inefficient phagocytosis could be enhanced by treatment of EAhu with antiglobulin from the rabbit, suggesting that it is caused by a low degree of activity of opsonizing antibodies rather than special properties of the erythrocytes themselves. Several lines of evidence suggested that both FcR subsets of ovine BMM recognize both ovine IgG1 and IgG2. In contrast, bovine IgG1 reacts with one FcR subset and bovine IgG2 interacts inefficiently with all FcR of ovine BMM. 相似文献
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Ma Z Mizukoshi T Khatlani TS Okuda M Onishi T 《Veterinary immunology and immunopathology》2000,77(3-4):321-327
The serum amyloid A (SAA) protein is a characteristic and sensitive acute phase reactant in all vertebrates investigated. We molecularly cloned the equine cDNA encoding SAA from the liver of a healthy horse by polymerase chain reaction (PCR). The cloned cDNA is 480 bases in length, and contains an open reading frame (ORF) of 387 nucleotides encoding a precursor SAA protein of 128 amino acids. The precursor of horse SAA seems to have an 18-residue signal peptide and differs from the reported amino acid sequences of the horse SAA by substitution of valine at residue 81. It shows high homology with SAA amino acid sequence of other species such as dog (80.6%), mink (77.5%), human (76.9%) and duck (71.9%). An insertion of eight amino acids at residues between 85 and 92, as compared to human SAA, has also been found in horse SAA. The availability of the equine SAA cDNA will provide a useful reagent for studying its role in diseased horses. 相似文献
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Simmental thrombopathia is an inherited platelet disorder that closely resembles the platelet disorders described in Basset Hounds and Eskimo Spitz dogs. Recently, two different mutations in the gene encoding calcium diacylglycerol guanine nucleotide exchange factor I (CalDAG-GEFI) were described to be associated with the Basset Hound and Spitz thrombopathia disorders, and a third distinct mutation was identified in CalDAG-GEFI in thrombopathic Landseers of European Continental Type. The gene encoding CalDAG-GEFI was sequenced using DNA obtained from normal cattle and from a thrombopathic calf studied in Canada. The affected calf was found to have a nucleotide change (c.701 T>C), which would result in the substitution of a proline for a leucine within structurally conserved region two (SCR2) of the catalytic domain of the protein. This change is likely responsible for the thrombopathic phenotype observed in Simmental cattle and underscores the critical nature of this signal transduction protein in platelets. 相似文献
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Molecular cloning and characterization of bovine PRKAG3 gene: structure, expression and single nucleotide polymorphism detection 总被引：2，自引：0，他引：2
S.L. Yu J.E. Kim H.J. Chung K.C. Jung Y.J. Lee D.H. Yoon S.H. Lee I. Choi C.D.K. Bottema B.C. Sang & J.H. Lee 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2005,122(5):294-301
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The full length of gene encoding Fc receptor types III for bovine immunoglobulin G (boFcgammaRIII, CD16) was obtained with PCR from the c DNA library of bovine alveolar macrophages. Through molecular cloning and sequencing it is shown that the coding gene has 507 bp and codes for 168 amino acids. There are signal peptide, transmembrane spanning domain and three potential N-linked glycosylation sites in the sequence. Compared with the boFcgammaRIII cDNA sequence cloned by Collins et al, it deletes 82 amino acids and has only one extracellular domain. It is suggested that this cDNA fragment is a special form of the gene structure of bovine FcgammaRIIIA (CD16-II). 相似文献
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Nishimura Y Miyazawa T Ikeda Y Izumiya Y Nakamura K Sato E Mikami T Takahashi E 《Veterinary immunology and immunopathology》2000,73(3-4):353-359
We amplified the cDNA encoding the feline FcgammaRIIIA (CD16) homologue from peripheral blood mononuclear cells by polymerase chain reaction and cloned two forms of FCGR3A cDNA. Sequencing analysis revealed that the open reading frame of feline FCGR3A cDNA consists of 750 or 747 base pairs encoding 250 or 249 amino acid residues, respectively. Comparison of the predicted amino acid sequence of feline FCGR3A cDNA with those of other mammalians' homologues revealed that the extracellular domain has a relatively low homology. However, the cytoplasmic domain contained an 8-amino acid motif, Leu-Phe-Val-Val-Asp-Thr-Gly-Leu, which was considered to interact with an accessory molecule such as the gamma chain of Fc receptors for IgE to form heterodimeric complexes. 相似文献
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Wang J Fang J Guo J Teng Q Huang Z Gu J Shen H Zhou J 《Veterinary immunology and immunopathology》2007,117(3-4):266-274
The IL-2Ralpha chain (CD25, Tac) is an essential component of high affinity IL-2Rs, playing critical role for the immune specificity of antigen-activated T-cell clonal expansion. Up to now, no duck cytokine receptor has been described. Here, the cDNA segment of a duck cytokine receptor (duCD25), encoding a 226 aa precursor protein with a 20 aa signal peptide, was isolated. Then a novel mouse monoclonal antibody (mAb) was generated using the prokaryotically expressed duCD25 protein as immunogen. Using this mAb, the endogenous duCD25 molecule was localized on the surface of duck lymphocytes, and the duck IL-2-induced lymphocyte proliferation was further inhibited. Furthermore, flow cytometry analysis showed that duCD25 positive cells were upregulated in ducks infected with avian influenza virus (H9N2). Our findings confirm that duCD25 is a receptor of duck interleukin-2, and duCD25 positive cells play a potential role in H9N2 virus infection. 相似文献
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采用RT-PCR技术从中国西门塔尔牛睾丸组织总RNA中反转录FascDNA,将其克隆于pMD19-Tvector后进行测序分析,并对其表达的蛋白结构功能进行预测、分析。结果表明:牛的FascDNA序列为1109bp,编码323个氨基酸残基,在氨基酸序列上与羊、猪、人、小鼠的相似性分别为90.5%、65.3%、56.7%和48.6%。Fas蛋白的胞外区有2个糖基化位点和3个富含半胱氨酸残基的结构亚域,对Fas蛋白的定位及凋亡信号识别有重要作用。牛与羊、猪、人、小鼠Fas的死亡结构域(Death domain,DD)氨基酸序列的相似性分别为94.3%、68.5%、59.6%和70.8%,体现了该结构在各物种间较强的保守性及接受凋亡信号诱导靶细胞凋亡的重要性。组织表达谱发现,Fas不仅表达于牛的淋巴、脾等淋巴系统,而且高表达于牛生殖系统的睾丸中,这对于进一步阐明Fas在公牛精子发生过程中的调控作用奠定基础。 相似文献
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IL-4 and IL-13 share a wide range of activities on monocytes, epithelial cells and B cells and thus play an important role in host defense. Many of these activities are not conserved among species as human, but not murine, B cells are thought to be responsive to IL-13. We previously demonstrated that human IL-13 is highly conserved at the nucleic acid level with a candidate bovine IL-13 cDNA homologue. Moreover, recombinant human IL-13 stimulates Ig secretion by appropriately activated bovine B cells. These studies have been extended to examining Ig class switching at both the protein and mRNA levels in addition to examining other markers of cellular activation. Our results suggest that IL-13 influences B cell differentiation by enhancing IgM, IgG1, and IgE production. IL-13 stimulation alone increases MHC class II expression and progression through cell cycle, although at lower levels in comparison to rboIL-4. The biology of the receptors for IL-4 and IL-13 is complex and raises several key questions with regard to IL-4-dependent and -independent mechanisms of host immunomodulation. Recent studies suggest that at least four chains are involved. These include the p140 IL-4 binding chain (IL-4Ralpha), the common gamma chain (gammac chain), IL-13 receptor alpha- chain (IL-13Ralpha-1) and the IL-13 receptor alpha-2 chain (IL-13Ralpha-2). We have recently cloned cDNAs for the bovine homologues of the IL-13Ralpha-1 and IL-4Ralpha chains and evaluated mRNA expression for a variety of cell types following stimulation. The expression patterns and their implications for receptor chain utilization in signaling via these key TH2 signature cytokines will be discussed. 相似文献
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Li AH Moon SU Park YK Na BK Hwang MG Oh CM Cho SH Kong Y Kim TS Chung PR 《Veterinary parasitology》2006,141(3-4):251-259
Taenia solium metacestode, a larval pork tapeworm, is a causative agent of neurocysticercosis, one of the most common parasitic diseases in the human central nervous system. In this study, we identified a cDNA encoding for a cathepsin L-like cysteine protease from the T. solium metacestode (TsCL-1) and characterized the biochemical properties of the recombinant enzyme. The cloned cDNA of 1216 bp encoded 339 amino acids with an approximate molecular weight of 37.6 kDa which containing a typical signal peptide sequence (17 amino acids), a pro-domain (106 amino acids), and a mature domain (216 amino acids). Sequence alignments of TsCL-1 showed low sequence similarity of 27.3-44.6 to cathepsin L-like cysteine proteases from other helminth parasites, but the similarity was increased to 35.9-55.0 when compared to mature domains. The bacterially expressed recombinant protein (rTsCL-1) did not show enzyme activity; however, the rTsCL-1 expressed in Pichia pastoris showed typical biochemical characteristics of cysteine proteases. It degraded human immunoglobulin G (IgG) and bovine serum albumin (BSA), but not collagen. Western blot analysis of the rTsCL-1 showed antigenicity against the sera from patients with cysticercosis, sparganosis or fascioliasis, but weak or no antigenicity against the sera from patients with paragonimiasis or clonorchiasis. 相似文献
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鸡IL—15基因的分子克隆及其有关特性的研究 总被引：5，自引：1，他引：4
实验应用聚合酶链式反应技术从鸡脾淋巴细胞中克隆得到了白细胞介素-15基因，序列分析表明与已发表的鸡白细胞介素-15基因完全一致，核苷酸序列和推导的氨基酸序列与牛的最接近，同源性分别为46%和31%，与哺乳动物白细胞介素-15序列类似，有4个高度保守的半胱氨酸残基，同时本研究也用此方法对鸡脾脏、法氏囊、胸腺、哈德氏腺和盲肠扁桃体等淋巴器官的淋巴细胞中鸡白细胞介素-15mRNA的表达进行了研究，结果表明这些器官的淋巴细胞均表达mRNA。在实验还用有丝分裂原ConA对鸡脾淋巴细胞进行活化，观察活化的淋巴细胞表达白细胞介素-15mRNA的情况，结果发现白细胞介素-15mRNA在活化的脾淋巴细胞中表达量升高。 相似文献
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Schwyzer M Fischer-Bracher C Fraefel C Bächi T Nuñez R Engels M Ackermann M 《Veterinary microbiology》2002,86(1-2):165-174
Herpes simplex virus-1 (HSV-1) based amplicon vectors are promising gene delivery vehicles because they have a large transgene capacity and can efficiently transduce many different cell types, including non-dividing cells, of various animal species. The Circ protein of bovine herpesvirus-1 (BHV-1) is a myristylated virion component of unknown function. Preliminary experiments with a circ gene deletion mutant indicated that Circ may influence the host's immune response by downregulating MHC-II expression in bovine monocytes. To get more insight into the function of Circ, amplicon vectors were constructed with various open reading frames (ORFs) under the control of the HSV-1 IE4/5 promoter: (i) the Circ ORF alone, (ii) a fusion ORF encoding an N-terminal Circ fused to the enhanced green fluorescent protein (eGFP), (iii) the eGFP ORF alone, and (iv) the Circ ORF in the inverted orientation. Upon helpervirus-free packaging into HSV-1 amplicon particles and transduction of Vero cells, both Circ alone and the Circ-eGFP fusion protein produced a punctate pattern within the cytoplasm, suggesting membrane association of the myristylated protein. In contrast, eGFP alone was evenly distributed over the cytoplasm of transduced cells. Upon infection of bovine buffy-coat cells, it was observed that cells of the monocyte lineage but not lymphocytes were transduced. Transgene expression reached a peak around 20h after transduction and lasted for at least 90h. Transduced monocytes underwent specific morphological changes, which may be attributed to Circ synthesis. 相似文献