Expression of recombinant herpes simplex virus type 2 glycoprotein D by high-density cell culture of <Emphasis Type="Italic">Spodoptera frugiperda</Emphasis>

Herpes simplex virus type 2 (HSV-2) is the major cause of genital herpes in humans. The glycoprotein D of HSV-2 (gD2) is a promising subunit vaccine candidate for the treatment of genital herpes. The aim of the present study was to express a biologically active recombinant gD2 in eukaryotic baculovirus system in quantities sufficient for further studies. Human cDNA encoding a gD2 protein with 393 amino acids was subcloned into the pFastBac HTb vector and the recombinant protein was expressed in Spodoptera frugiperda (Sf9) cells by high-density cell culture. In a stirred bioreactor, the key limiting factors including glucose concentration, glutamine concentration and dissolved oxygen (DO) were optimized for high-density cell growth. The Sf9 cell density could reach 9.6×10⁶ cells/mL and the yield of recombinant gD2 protein was up to 192 mg/L in cell culture under the optimal conditions of 15 mM glucose, 0.4 g/L glutamine and 40% DO. Production of significant amounts of pure, full-length gD2 opened up the possibility to investigate novel functions of gD2. Moreover, the purified recombinant gD2 protein revealed a partial prophylactic immune function in genital herpes of guinea pigs infected with HSV-2.     

A chimeric baculovirus displaying bovine herpesvirus-1 (BHV-1) glycoprotein D on its surface and their immunological properties

The ability of a recombinant baculovirus containing the ectodomain of the mature sequence of glycoprotein D (gD) fused to the amino-terminus of baculoviral glycoprotein gp64 to display gD on its surface and to serve as an improved immunogen against bovine herpesvirus-1 was tested. The gD–gp64 fusion protein was correctly expressed on the virus particles as revealed by immunomicroscopy assays. Mice immunized with 5 × 10⁸ plaque forming units developed antibodies that specifically reacted in an enzyme-linked immunosorbent assay with recombinant gD and whole bovine herpesvirus-1. These antibodies were able to neutralize bovine herpesvirus-1 in vitro, whereas those elicited by a version of gD expressed in Escherichia coli did not. Our data demonstrated that the display on the virion surface of recombinant baculovirus can provide a tool for the development of recombinant vaccines against bovine herpesvirus-1.     

Disulfide bond structure of glycoprotein D of herpes simplex virus types 1 and 2.

Glycoprotein D (gD) is a structural component of the herpes simplex virus envelope which is essential for virus penetration. The function of this protein is highly dependent on its structure, and its structure is dependent on maintenance of three intact disulfide bonds. gD contains six cysteines in its ectodomain whose spacing is conserved among all its homologs in other alphaherpesviruses as well as Marek's disease virus. For other proteins, conservation of cysteine spacing correlates with conservation of disulfide bond structure. We have now solved the disulfide bond structure of gD-1 and gD-2 of herpes simplex virus types 1 and 2, respectively. Two approaches were used. First, we constructed 15 double-Cys mutants of gD-1, representing all possible disulfide pairs. In each case, codons for cysteines were changed to serine. We reasoned that if two cysteines normally form a disulfide bond, double mutations which eliminate one proper bond should be less harmful to gD structure than double mutations which eliminate two disulfide bonds. The mutated genes were cloned into a eucaryotic expression vector, and the proteins were expressed in transiently transfected cells. Three double mutations, Cys-1,5, Cys-2,6, and Cys-3,4 permitted gD-1 folding, processing, transport to the cell surface, and function in virus infection, whereas 12 other double mutations each produced a malfolded and nonfunctional protein. Thus, the three functional double-Cys mutants may represent the actual partners in disulfide bond linkages. The second approach was to define the actual disulfide bond structure of gD by biochemical means. Purified native gD-2 was cleaved by CNBr and proteases, and the peptides were separated by high-performance liquid chromatography. Disulfide-linked peptides were subjected to N-terminal amino acid sequencing. The results show that cysteine 1 (amino acid [aa] 66) is bonded to cysteine 5 (aa 189), cysteine 2 (aa 106) is bonded to cysteine 6 (aa 202), and cysteine 3 (aa 118) is bonded to cysteine 4 (aa 127). Thus, the biochemical analysis of gD-2 agrees with the genetic analysis of gD-1. A similar disulfide bond arrangement is postulated to exist in other gD homologs.     

重组人死亡受体6胞外结构域的制备及与淀粉样前体蛋白N端片段相互作用鉴定

人淀粉样前体蛋白氨基端切割片段(a cleaved amino-terminal fragment of amyloid precursor protein,N-APP)结合死亡受体6(Death receptor-6,DR6),会触发神经元和轴突依赖天冬氨酸特异性半胱氨酸蛋白酶的自我毁灭过程,从而导致阿尔茨海默病(Alzheimer's disease,AD)的发生。为了在分子水平上研究N-APP-DR6诱导神经元退化途径,制备大量纯化的重组DR6胞外结构域以及鉴定NAPP和DR6胞外结构域的结合位点是关键。从甲醇毕赤酵母中成功表达并纯化了重组DR6胞外域(aa42-349),得率高达90 mg/L。为了验证DR6和NAPP的相互作用关系,构建谷胱甘肽转移酶-死亡受体6(GST-DR6)(aa42-349)融合蛋白原核表达质粒,转化大肠杆菌(Escherichia coli,E.coli)BL21,表达融合蛋白GST-DR6(aa42-349),同时纯化得到DR6的配体NAPP,GST pull-down结果显示DR6与NAPP能够在细胞外发生相互作用。     

Viral determinants of the variable sensitivity of herpes simplex virus strains to gD-mediated interference.

Cells that express glycoprotein D (gD) of herpes simplex virus type 1 (HSV-1) resist infection by HSV-1 and HSV-2 because of interference with viral penetration. The results presented here show that both HSV-1 and HSV-2 gD can mediate interference and that various HSV-1 and HSV-2 strains differ in sensitivity to this interference. The relative degree of sensitivity was not necessarily dependent on whether the cell expressed the heterologous or homologous form of gD but rather on the properties of the virus. Marker transfer experiments revealed that the allele of gD expressed by the virus was a major determinant of sensitivity to interference. Amino acid substitutions in the most distal part of the gD ectodomain had a major effect, but substitutions solely in the cytoplasmic domain also influenced sensitivity to interference. In addition, evidence was obtained that another viral gene(s) in addition to the one encoding gD can influence sensitivity to interference. The results indicate that HSV-1 and HSV-2 gD share determinants required to mediate interference with infection by HSV of either serotype and that the pathway of HSV entry that is blocked by expression of cell-associated gD can be cleared or bypassed through subtle alterations in virion-associated proteins, particularly gD.     

单纯疱疹病毒1型囊膜糖蛋白gD在大肠杆菌中的表达、纯化及其免疫活性的鉴定

目的:在大肠杆菌中表达1型单纯疱疹病毒(HSV-1)囊膜糖蛋白gD,纯化重组蛋白并对其免疫活性进行鉴定。方法:将HSV-1 gD 基因克隆入原核表达载体pET-28b,利用异丙基-B-D-硫代吡喃半乳糖苷(IPTG)诱导重组质粒转化的大肠杆菌,探讨IPTG浓度、诱导时间、诱导温度对重组蛋白表达的影响;盐酸胍裂解变性包涵体,镍柱亲和层析法纯化gD蛋白,并对纯化后的蛋白进行透析复性;Western blot和ELISA检测gD蛋白的免疫活性。结果:酶切和测序结果表明gD基因克隆入pET-28b载体。该重组质粒转化的大肠杆菌经IPTG诱导后重组蛋白主要以包涵体形式存在,大小约40kDa。gD蛋白诱导表达的最佳条件为0.5mmol/L IPTG于37℃诱导8h。镍柱亲和层析法纯化获得的gD蛋白总量为3.1mg/L,透析复性后获得的gD蛋白总量为1.3mg/L,复性率为41.37%。Western blot及ELISA检测表明表达的gD蛋白具有免疫活性。结论:在大肠杆菌中表达并纯化获得具有免疫活性的HSV-1 gD蛋白,为进一步制备HSV-1诊断试剂和预防疫苗奠定了基础。     

Immune response and cytokine production following immunization with experimental herpes simplex virus 1 (HSV-1) vaccines

Balb/c mice were immunized with the recombinant fusion protein gD1/313 (FpgD1/313 representing the ectodomain of HSV-1 gD), with the non-pathogenic ANGpath gE-del virus, with the plasmid pcDNA3.1-gD expressing full-length gD1 and with the recombinant immediate early (IE) HSV-1 protein ICP27. Specific antibodies against these antigens (as detected by ELISA) reached high titers with the exception of the DNA vaccine. High-grade protection against challenge with the virulent strain SC16 was found following immunization with the pcDNA3.1-gD plasmid and with the gE-del virus. Medium grade, but satisfactory protection developed after immunization with the FpgD1/313 and minimum grade protection was seen upon immunization with the IE/ICP27 polypeptide. A considerable response of peripheral blood cells (PBL) and splenocytes in the lymphocyte transformation test (LTT) was found in mice immunized with FpgD1/313, with the pcDNA3.1-gD plasmid and with the live ANGpathgE-del virus. For lymphocyte stimulation in vitro, the FpgD1/313 antigen was less effective than the purified gD1/313 polypeptide (cleaved off from the fusion protein); both proteins elicited higher proliferation at the 5 mug per 0.1 mL dose than at the 1 mug per 0.1 mL dose. The secretion of Th type 1 (TNF, IFN-gamma and IL-2) and Th type 2 (IL-4 and IL-6) cytokines was tested in the medium fluid of purified PBL and splenocyte cultures; their absolute values were expressed in relative indexes. The PBL from FpgD1/313 immunized mice showed increased secretion of both T(H)1 (TNF) as well as T(H)2 (IL-4) cytokines (7-10-fold, respectively). Splenocytes from FpgD1/313 immunized mice showed a significant (23-fold) increase in IL-4 production.     

单纯疱疹病毒I型糖蛋白D胞外区的真核表达及生物学活性分析

单纯疱疹病毒 (Herpes simplex virus,HSV) 包膜糖蛋白D (glycoprotein D,gD) 是HSV的结构蛋白之一,具有重要抗原表位,是目前疫苗研究的热点。为了分离纯化HSV gD1糖蛋白胞外区片段并对其生物学活性进行分析,本研究将化学合成的gD1胞外区基因片段克隆至真核表达载体pCEP4,重组质粒转染HEK293细胞进行瞬时表达,产物经Western blotting检测后用亲和层析法进行分离纯化,ELISA检测其抗原性。以纯化的重组蛋白作为抗原免疫小鼠,ELISA测血清特异性抗体效价以评价其免疫原性。构建的重组质粒经测序显示基因序列完全正确。表达产物的Western blotting分析发现,在相对分子量约46 kDa处有外源蛋白表达,与预期蛋白带一致。用Ni柱得到了纯化的重组gD1蛋白,ELISA检测显示其具有良好的抗原性,免疫小鼠7周后血清中抗体效价达到5×103。重组gD1蛋白的抗原性及免疫原性分析为HSV检测试剂和基因重组亚单位疫苗的研制提供了实验依据。     

II型单纯疱疹病毒糖蛋白D的晶体结构解析

II型单纯疱疹病毒 (HSV-2) 糖蛋白D (Glycoprotein D,gD) 在介导该病毒入侵到宿主细胞中起着关键作用。为了更好地研究gD在病毒侵入过程中的作用机制,利用杆状病毒表达系统表达了gD胞外部分区域 (1~285 aa),通过Ni-NTA亲和层析以及分子排阻层析纯化后,得到的带His标签的分泌型可溶蛋白,用悬滴法对该蛋白进行了晶体筛选,获得了高质量的晶体。晶体生长条件为0.1 mol/L Hepes缓冲液 (pH 7.2),5％ (V/V) 2-甲基-2,4-戊二醇 (MPD),10％     

The domains of glycoprotein D required to block apoptosis induced by herpes simplex virus 1 are largely distinct from those involved in cell-cell fusion and binding to nectin1

Glycoprotein D (gD) interacts with two alternative protein receptors, nectin1 and HveA, to mediate herpes simplex virus (HSV) entry into cells. Fusion of the envelope with the plasma membrane requires, in addition to gD, glycoproteins gB, gH, and gL. Coexpression of the four glycoproteins (gD, gB, gH, and gL) promotes cell-cell fusion. gD delivered in trans is also capable of blocking the apoptosis induced by gD deletion viruses grown either in noncomplementing cells (gD(-/-)) or in complementing cells (gD(-/+)). While ectopic expression of cation-independent mannose-6 phosphate receptor blocks apoptosis induced by both stocks, other requirements differ. Thus, apoptosis induced by gD(-/-) virus is blocked by full-length gD (or two gD fragments reconstituting a full-length molecule), whereas ectopic expression of the gD ectodomain is sufficient to block apoptosis induced by gD(-/+) virus. In this report we took advantage of a set of gD insertion-deletion mutants to map the domains of gD required to block apoptosis by gD(-/-) and gD(-/+) viruses and those involved in cell-cell fusion. The mutations that resulted in failure to block apoptosis were the same for gD(-/-) and gD(-/+) viruses and were located in three sites, one within the immunoglobulin-type core region (residues 125, 126, and 151), one in the upstream connector region (residues 34 and 43), and one in the C-terminal portion of the ectodomain (residue 277). A mutant that carried amino acid substitutions at the three glycosylation sites failed to block apoptosis but behaved like wild-type gD in all other assays. The mutations that inhibited polykaryocyte formation were located in the upstream connector region (residues 34 and 43), at the alpha1 helix (residue 77), in the immunoglobulin core and downstream regions (residue 151 and 187), and at the alpha3 helix (residues 243 and 246). Binding of soluble nectin1-Fc to cells expressing the mutant gDs was generally affected by the same mutations that affected fusion, with one notable exception (Delta277-310), which affected fusion without hampering nectin1 binding. This deletion likely identifies a region of gD involved in fusion activity at a post-nectin1-binding step. We conclude that whereas mutations that affected all functions (e.g., upstream connector region and residue 151) may be detrimental to overall gD structure, the mutations that affect specific activities identify domains of gD involved in the interactions with entry receptors and fusogenic glycoproteins and with cellular proteins required to block apoptosis. The evidence that glycosylation of gD is required for blocking apoptosis supports the conclusion that the interacting protein is the mannose-6 phosphate receptor.     

Striking similarity of murine nectin-1alpha to human nectin-1alpha (HveC) in sequence and activity as a glycoprotein D receptor for alphaherpesvirus entry

A cDNA encoding the murine homolog of human nectin-1alpha (also known as poliovirus receptor-related protein 1 [Prr1] and herpesvirus entry protein C [HveC]) was isolated. The protein encoded by this cDNA proved to be 95% identical in sequence to the human protein and to have similar herpesvirus entry activity. Upon expression of the murine cDNA in hamster cells resistant to alphaherpesvirus entry, the cells became susceptible to the entry of herpes simplex virus types 1 and 2 (HSV-1 and -2), pseudorabies virus, and bovine herpesvirus 1. HSV envelope glycoprotein D (gD), a viral ligand for human nectin-1alpha, is also a ligand for the murine homolog based on evidence that (i) a soluble hybrid protein composed in part of the murine nectin-1 ectodomain bound specifically to purified soluble forms of HSV-1 and HSV-2 gD as demonstrated by enzyme-linked immunosorbent assay, (ii) a soluble hybrid of HSV-1 gD bound to hamster cells expressing murine nectin-1alpha but not to control cells, and (iii) cells expressing both murine nectin-1alpha and one of the alphaherpesvirus gDs were resistant to entry of HSV-1, indicative of interference with entry resulting from interactions of cell-associated gD with the entry receptor. Northern blot analysis revealed that nectin-1 is expressed in most of the mouse tissues examined and at high levels in the brain, skin, and kidneys. Immunocytochemical localization demonstrated the presence of nectin-1 in epithelial cells of the mouse vagina and also in neuronal cells of the central nervous system, suggesting an expression pattern relevant to both infection at a portal of entry and spread of infection to the brain.     

An efficient production and characterization of HIV-1 gp41 ectodomain with fusion peptide in Escherichia coli system

We demonstrated a high level expression and purification of recombinant human immunodeficiency virus type 1 gp41 ectodomain (gp41e-FP) using glass bead approach with a final yield of 12±2mg/L bacterial culture. The proper folding of gp41e-FP encompassing the fusion peptide (FP) was ascertained by circular dichroism (CD) measurement and recognition by NC-1 antibody. The latter assay revealed stabilization of the gp41 coiled coil structure in the presence of liposome dispersion. The differential affinity of gp41e-FP and gp41e (devoid of FP) by NC-1 suggested an aggregated state for gp41e-FP and/or possible proximity of the fusion peptide domain to the coiled coil structure of gp41 ectodomain. Perfluorooctanoate (PFO)-PAGE electrophoresis experiment revealed the trimeric propensity of the recombinant gp41e-FP. In comparison to gp41e, the lipid mixing activity of gp41e-FP was two-fold higher suggesting a role of FP in promoting membrane fusion. The present approach to efficiently and quantitatively preparing the functional full-length recombinant gp41 ectodomain protein can be employed for structural and biomedical investigations and the extraction of other inclusion body-embedded recombinant proteins.     

Nectin2alpha (PRR2alpha or HveB) and nectin2delta are low-efficiency mediators for entry of herpes simplex virus mutants carrying the Leu25Pro substitution in glycoprotein D

The receptors for entry of herpes simplex viruses 1 and 2 (HSV-1 and -2), widely expressed in human cell lines, are members of a subset of the immunoglobulin superfamily exemplified by herpesvirus entry mediator C (HveC) and the herpesvirus immunoglobulin-like receptor (HIgR). This report focuses on two members of this subset, herpesvirus entry mediator B (HveB), recently designated nectin2/PRR2alpha, and its splice variant isoform, nectin2/PRR2delta. Nectin2alpha and -delta share the ectodomain but differ in the transmembrane and cytoplasmic regions. HveB was reported to enable entry of HSV-1 carrying mutations in glycoprotein D (gD) and of HSV-2, but not of wild-type (wt) HSV-1. We report that (i) both nectin2alpha and -delta served as receptors for the entry of HSV-1 mutant viruses HSV-1(U10) and -(U21) and AP7(r) that carry the Leu25Pro substitution in gD but not for HSV-1 mutants U30 and R5000 that carry the Ser140 or Ala185 substitution in gD. All of these mutants were able to overcome the block to entry mediated by expression of wt gD. (ii) Infection of cells expressing nectin2alpha or -delta required exposure to multiplicities of infection about 100-fold higher than those required to infect cells expressing HveC or HIgR. (iii) gD from HSV-1(U21) bound in vitro soluble forms of nectin2. The association was weaker than that to the soluble form of HveC/HIgR. Binding of wt HSV-1 gD to soluble nectin2 was not detectable. (iv) A major region of nectin2 functional in virus entry mapped to the V domain, located at the N terminus.     

Expression, purification, and characterization of human acetyl-CoA carboxylase 2

The full-length human acetyl-CoA carboxylase 1 (ACC1) was expressed and purified to homogeneity by two separate groups (Y.G. Gu, M. Weitzberg, R.F. Clark, X. Xu, Q. Li, T. Zhang, T.M. Hansen, G. Liu, Z. Xin, X. Wang, T. McNally, H. Camp, B.A. Beutel, H.I. Sham, Synthesis and structure-activity relationships of N-{3-[2-(4-alkoxyphenoxy)thiazol-5-yl]-1-methylprop-2-ynyl}carboxy derivatives as selective acetyl-CoA carboxylase 2 inhibitors, J. Med. Chem. 49 (2006) 3770-3773; D. Cheng, C.H. Chu, L. Chen, J.N. Feder, G.A. Mintier, Y. Wu, J.W. Cook, M.R. Harpel, G.A. Locke, Y. An, J.K. Tamura, Expression, purification, and characterization of human and rat acetyl coenzyme A carboxylase (ACC) isozymes, Protein Expr. Purif., in press). However, neither group was successful in expressing the full-length ACC2 due to issues of solubility and expression levels. The two versions of recombinant human ACC2 in these reports are either truncated (lacking 1-148 aa) or have the N-terminal 275 aa replaced with the corresponding ACC1 region (1-133 aa). Despite the fact that ACC activity was observed in both cases, these constructs are not ideal because the N-terminal region of ACC2 could be important for the correct folding of the catalytic domains. Here, we report the high level expression and purification of full-length human ACC2 that lacks only the N-terminal membrane attachment sequence (1-20 and 1-26 aa, respectively) in Trichoplusia ni cells. In addition, we developed a sensitive HPLC assay to analyze the kinetic parameters of the recombinant enzyme. The recombinant enzyme is a soluble protein and has a K(m) value of 2 microM for acetyl-CoA, almost 30-fold lower than that reported for the truncated human ACC2. Our recombinant enzyme also has a lower K(m) value for ATP (K(m)=52 microM). Although this difference could be ascribed to different assay conditions, our data suggest that the longer human ACC2 produced in our system may have higher affinities for the substrates and could be more similar to the native enzyme.     

采用我国痘苗病毒天坛株载体表达单纯疱疹病毒Ⅰ型糖蛋白D

木文从单纯疱疹病毒Ⅰ型(HSV-1)基因组EcoRI H片段中分离出含有糖蛋白D(gD)基因的2.5kb DWA片段,插入带有痘苗病毒天坛株TK基因区段的pJC—2质粒p7.5k启动子的下游,转染TK~-143细胞,获得带有HSV-1 gD基因的重组痘苗病毒。采用HSV-1 gD单克隆抗体免疫胶体金技术进行电镜观察表明,重组痘苗病毒感染的细胞内有特异性HSV-1 gD抗原.重组病毒免疫家兔后6周可产生明显的HSV-1中和抗体。     

Conformational states of the severe acute respiratory syndrome coronavirus spike protein ectodomain

The severe acute respiratory syndrome coronavirus enters cells through the activities of a spike protein (S) which has receptor-binding (S1) and membrane fusion (S2) regions. We have characterized four sequential states of a purified recombinant S ectodomain (S-e) comprising S1 and the ectodomain of S2. They are S-e monomers, uncleaved S-e trimers, cleaved S-e trimers, and dissociated S1 monomers and S2 trimer rosettes. Lowered pH induces an irreversible transition from flexible, L-shaped S-e monomers to clove-shaped trimers. Protease cleavage of the trimer occurs at the S1-S2 boundary; an ensuing S1 dissociation leads to a major rearrangement of the trimeric S2 and to formation of rosettes likely to represent clusters of elongated, postfusion trimers of S2 associated through their fusion peptides. The states and transitions of S suggest conformational changes that mediate viral entry into cells.     

荧光蛋白标签对gD囊膜蛋白在BHK-21细胞亚细胞定位的影响

【目的】探究荧光蛋白标签对马疱疹病毒I型(Equine herpes virus type 1,EHV-1)gD囊膜蛋白亚细胞定位的影响。【方法】以EHV-1基因组为模板利用PCR扩增gD全基因,分别克隆至pAcGFP1-C1和p Ds Red2-N1质粒,构建p Ac-GFP-gD(GFP-gD)和p Ds-gD-Red(gD-Red)重组质粒;将GFP基因插入gD基因信号肽序列之后并克隆至PVAX-1质粒,构建PVAX-S-GFP-gD’(S-GFP-gD’)重组质粒;将Flag标签序列与gD囊膜蛋白N端序列融合后并克隆至p VAX-1表达载体,构建p VAX-Flag-gD(Flag-gD)重组质粒。将4种不同重组真核表达质粒分别转染BHK-21细胞,通过激光共聚焦显微镜对不同融合蛋白gD进行亚细胞定位。【结果】成功构建4种不同的融合蛋白gD真核表达载体;在BHK-21细胞单独表达时,不同融合蛋白gD绝大部分都定位于高尔基体,极少量定位于细胞核内。【结论】不同插入位点的荧光蛋白标签对gD囊膜蛋白亚细胞定位无明显影响,这对今后研究其它蛋白亚细胞定位提供参考。     

Soluble LRIG2 Ectodomain Is Released from Glioblastoma Cells and Promotes the Proliferation and Inhibits the Apoptosis of Glioblastoma Cells In Vitro and In Vivo in a Similar Manner to the Full-Length LRIG2

The human leucine-rich repeats and immunoglobulin-like domains (LRIG) gene family contains LRIG1, 2 and 3, encoding integral membrane proteins with an ectodomain, a transmembrane domain and a cytoplasmic tail. LRIG1 negatively regulates multiple receptor tyrosine kinases signaling including the epidermal growth factor receptor (EGFR) and is a proposed tumor suppressor. The soluble LRIG1 ectodomain is demonstrated to be shed naturally and inhibit the progression of glioma. However, little is known regarding the functions of LRIG2. In oligodendroglioma, LRIG2 expression is associated with poor survival, suggesting that LRIG2 might have different functions compared with LRIG1. Since soluble LRIG1 ectodomain has a similar function to the full-length LRIG1, we hypothesize that the different roles exerted by LRIG2 and LRIG1 result from the difference of their ectodomains. Here, we addressed the functions of LRIG2 and LRIG2 ectodomain in the proliferation and apoptosis of glioma and the possible underlying mechanisms. Firstly, we found that LRIG2 expression levels positively correlated with the grade of glioma. Further, we demonstrated for the first time that soluble LRIG2 ectodomain was capable of being released from glioblastoma cells and exerted a pro-proliferative effect. Overexpression of LRIG2 ectodomain promoted the proliferation and inhibited the apoptosis of glioblastoma cells in vitro and in vivo in a similar manner to the full-length LRIG2. Both full-length LRIG2 and LRIG2 ectodomain were found to physically interact with EGFR, enhance the activation of EGFR and its downstream PI3 K/Akt pathway. To our knowledge, this is the first report demonstrating that soluble LRIG2 ectodomain is capable of being released from glioblastoma cells and exerts a similar role to the full-length LRIG2 in the regulation of EGFR signaling in the progression of glioblastoma. LRIG2 ectodomain, with potent pro-tumor effects, holds promise for providing a new therapeutic target for the treatment of glioblastoma.