Mycobacterium tuberculosis (Mtb) can survive for a long time in vivo and evade host immune attacks, primarily through transcriptional regulation mediated by transcription regulators. JTY_2262 (homologous with Rv2250c) belongs to the Tetracycline Repressor (TetR) family of regulators, and its function is currently unclear. In this study, we combined JTY_2262 overexpressed transcriptomics and electrophoretic mobility shift assays (EMSA) to identify novel targets regulated by JTY_2262. The cofactors containing Cys, VC, VB1, VB3, VB6, Pb2+, Cu2+ and Li + inhibit the binding between JTY_2262 and the JTY_2045 (homologous with rv2031c) promoter. Overall, this study demonstrates that JTY_2262 is a versatile regulator. Under different environmental conditions, JTY_2262 senses concentration variations of specific cofactors. By modulating its DNA-binding affinity accordingly, JTY_2262 regulates targeted gene expression, enabling bacteria to adapt their metabolic machinery and physiological state to better adapt the changing environment.

Autophagy serves as a crucial defense mechanism against Mycobacterium tuberculosis (Mtb) survival within infected macrophages. Transcription factor EB (TFEB) and upstream stimulatory factor 2 (USF2) belong to the bHLH-Zip family and regulate the transcription of autophagy-related genes, thereby modulating host-pathogen interactions. However, the mechanisms by which Mtb regulates these transcriptional regulatory factors to inhibit infection remain largely unexplored. This study demonstrated that PE_PGRS23 protein of Mtb impairs macrophage autophagy by inhibiting the transcription of the autophagy gene, thereby enhancing Mtb intracellular survival. Importantly, PE_PGRS23 facilitates the nuclear translocation of TFEB through PI3K-AKT-mTOR-mediated dephosphorylation. Concurrently, PE_PGRS23 promotes the nuclear translocation of USF2, which competes with TFEB for binding to the MAPLC3 promoter, ultimately suppressing MAPLC3 transcription and inhibiting autophagy. Furthermore, murine infection models demonstrated that PE_PGRS23 enhances Mtb survival and exacerbates Mtb-induced lung tissue damage. These findings underscore the critical role of the Mtb PE_PGRS23 protein in inhibiting autophagy by competitively binding of TFEB and USF2 at the MAPLC3 promoter. This mechanism facilitates the intracellular persistence of Mtb, providing theoretical insights into how the pathogen evades innate immune responses.

Spatiotemporal coordination of peptidoglycan (PG) synthesis with the cell cycle is fundamental to bacterial life, yet how the rate-limiting step of PG synthesis is dynamically coupled to this process remains poorly understood. Here, we uncover that the conserved STK/STP-IreB module controls MurZ in Streptococcus suis through a phosphorylation-tunable liquid-liquid phase separation (LLPS) switch. Non-phosphorylated IreB dimers assemble into a septal ring that binds and inhibits MurZ. STK-mediated phosphorylation drives dimer-to-oligomer transition and LLPS, forming a biomolecular condensate, thereby relieving MurZ inhibition. Time-lapse imaging reveals that the septal ring and the condensate dynamically interconvert with the cell cycle. Thus, IreB couples the rate-limiting step of PG synthesis with the cell cycle through reversible interconversion between an inhibitory ring and a phase-separated reservoir, revealing a phosphorylation-tunable LLPS switch as a paradigm for spatiotemporal regulation of cellular biosynthesis.

Mycobacterium tuberculosis (MTB), the causative agent of tuberculosis, is currently resistant to antibiotics and has undergone transcriptional adaptation to them, yet only a few transcription factors regulating mycobacterial drug resistance have been identified. In this study, the transcriptional regulatory protein Rv2250c of the TetR family was found to be a regulatory molecule of INH. Compared with wild-type strains, strains lacking the rv2250c gene showed higher minimum inhibitory concentrations (MICs) and greater intracellular survival in macrophages under INH stress. Furthermore, the INH competition with Rv2250c weakens its interaction with the efflux pump gene rv3728, thereby reducing its negative regulatory effect. This enhances the function of the MTB cell wall efflux pump, reducing the accumulation of ethidium bromide (EtBr) within the bacteria. In summary, we found that Rv2250c can regulate INH susceptibility by modulating the expression of efflux pump-encoding genes.

[Objective]This study aimed to develop an indirect ELISA detection method for antibodies against Mycobacterium avium subsp.paratuberculosis(MAP)in sheep,for providing an efficient and reliable technique for the epidemiological surveillance and serological testing of Johne's disease(JD)in sheep.[Method]In this study,the culture supernatant of the strain(MAP-XJB13)was isolated in the laboratory during earlier stage,which was selected as the MAP-coated antigen.The optimal reaction conditions and critical values for indirect ELISA were determined through the systematic screening and optimization of various parameters,including the coating solution and conditions,blocking solution and conditions,antigen coating concentration,serum dilution ratio,antibody incubation and color development time,brand of color development solution,sample dilution solution and enzyme-labeled secondary antibody protective solution.The efficacy of the developed indirect ELISA antibody detection method for sheep MAP was assessed in terms of sensitivity,specificity,repeatability,preservation period,and coincidence rate.Finally,the initially assembled reagent kits were utilized for the clinical detection of samples from in Heilongjiang and Inner Mongolia.[Result]The optimal conditions for the ELISA were determined as follows:the coating solution utilized as CBS buffer,with the coating condition process conducted at 37℃for 4 hours.The blocking solution comprised 5%fish gelatin,5%trehalose,and 12%PEG4000,with the blocking procedure also performed at 37℃for 2 hours.The antigen coating concentration was set at 80 µg·mL-1,the serum dilution ratio was 1:40,and the dilution ratio for the enzyme-labeled secondary antibody was 1:30 000.The incubation parameters included primary antibody incubation at 25℃for 30 minutes,followed by a 30-minute incubation of the enzyme-labeled secondary antibody,and a 15-minute color development phase.The color development solution employed was Biodragon,while the sample dilution solution consisted of 1%ovalbumin and 0.5%trehalose.Additionally,the protective solution for the enzyme-labeled secondary antibody contained 0.1%ovalbumin.The critical threshold for the developed indirect ELISA method for detecting antibodies against sheep MAP was determined to be 0.460,with a sensitivity of 95.89%and a specificity of 96.12%.The cross-reactivity analysis demonstrated that,based on the premise that the positive and negative results were valid,there was no cross-reactivity with the following:positive serum for Brucella in sheep,positive serum for Mycoplasma mycoides in sheep,positive serum for Corynebacterium pseudomycosis in goats,positive serum for tuberculosis in sheep,positive serum for peste des petits ruminants virus in goats,positive serum for peste des petits ruminants in sheep,and positive serum for poxvirus in sheep.The intra-batch and inter-batch coefficients of variation ranged from 0.754%to 7.812%and 1.252%to 7.277%,respectively,and the stability of the results was maintained for up to 8 months.The sheep MAP indirect ELISA antibody detection kit exhibited a positive concordance rate of 95.89%and a negative concordance rate of 95.55%when compared to the ID.vet MAP ELISA antibody detection kit,resulting in an overall concordance rate of 98.56%.The prevalence of MAP antibodies in sheep from Heilongjiang and Inner Mongolia was found to be 10.81%.[Conclusion]This study successfully developed an indirect ELISA method for the detection of antibodies MAP in sheep.The method exhibited exceptional specificity,high sensitivity and a long shelf life,thereby offering robust technical support for the prevention and management of JD.

Streptococcus suis, an important zoonotic pathogen capable of transmission from pigs to humans, represents a critical threat to both public health and the global pork industry. The increasing prevalence of multidrug-resistant S. suis strains, coupled with their ability to form biofilms, has necessitated the development of alternative antimicrobial strategies. In this study, we characterized the therapeutic potential of Ply113, an endolysin derived from an Enterococcus faecium phage, against S. suis. Ply113 has shown potent bactericidal activity against S. suis in vitro, with rapid time-kill characteristics and broad-spectrum efficiency against clinically prevalent serotypes (2, 3, 4, 7, and 9). Transmission electron microscopy analysis revealed that Ply113 induced distinct morphological alterations in S. suis, including cell wall disintegration and cytoplasmic leakage. This endolysin exhibited anti-biofilm functionality, eradicating biofilms formed by clinical strain of S. suis in a concentration-dependent manner. In murine models of bacteremia, a single administration of Ply113 provided complete protection against lethal S. suis infection, significantly decreasing the bacterial burden in the liver and spleen and attenuating organ injury. Additionally, Ply113 has been shown to be safe for mice, with no adverse effects. Taken together, our findings indicate that Ply113 is a promising alternative antimicrobial agent for combating biofilm-related infections caused by S. suis.

Mycobacterium abscessus and Mycobacterium marinum are nontuberculous mycobacteria that pose significant challenges due to their high drug resistance and persistence in hostile host environments. Aminoacyl-tRNA synthetases, such as isoleucyl-tRNA synthetase (IleRS), are crucial for protein synthesis and represent promising targets for antimicrobial development. This study investigates the role of IleRS in mycobacterial growth, metabolism, and pathogenesis using conditional gene silencing combined with microbiological, metabolomic, and transcriptomic analyses. Our findings indicate that IleRS is essential for mycobacterial growth and survival during infection. Depletion of IleRS disrupts branched-chain amino acid and pantothenate biosynthesis, leading to metabolic vulnerabilities and impaired persistence in macrophages and in mouse infection models. Based on our metabolic findings, we tested drug susceptibility and found that depletion of IleRS enhances sensitivity to pyrazinamide, highlighting a synergistic effect that could improve tuberculosis treatment. Furthermore, global gene set enrichment analysis reveals that IleRS knockdown might promote bacterial clearance by upregulating cholesterol metabolism and lysosome organization processes in macrophages. These results establish IleRS as a potential therapeutic target, offering new insights into reducing drug resistance and enhancing current treatment regimens for mycobacterial infections, including tuberculosis.

The mycobacterial cell wall is a complex structure that plays a critical role in resisting external environmental stress and contributing to pathogenesis, with mycolic acid being a key component in maintaining cell wall integrity. Moreover, the enzymes involved in cell wall synthesis are frequently targeted in antimycobacterial drug research. In this study, we demonstrate that the conserved extracellular DNase XthA from mycobacteria exhibits phospholipase A1 (PLA1) activity, whereas this activity is absent in non-pathogenic mycobacteria. Moreover, XthA PLA1 activity facilitates the formation of cord-like structures, promotes the proliferation of mycobacteria, and enhances their resistance to environmental stressors. Results from ethidium bromide and minimum inhibitory concentration assays suggest that XthA PLA1 activity reduces the permeability of the mycobacterial cell wall. Furthermore, analyses using scanning electron microscopy and mass spectrometry demonstrated that PLA1 activity contributes to cell wall integrity and enhances the synthesis of mycolic acids. Additionally, qPCR analysis indicated that XthA PLA1 activity upregulates the transcript of key genes involved in the MAs synthesis pathway. Collectively, these findings suggest that pathogenic mycobacteria utilize XthA PLA1 to facilitate cell wall functionality by regulating mycolic acid synthesis, thereby underscoring its potential as a drug target for disrupting the cell wall of pathogenic mycobacteria.

Salmonella enterica serovar Typhimurium, the causative agent of gastroenteritis, is one of the most successful intracellular pathogens. Although certain host factors for Salmonella infection have been unveiled, the factors mediating Salmonella entry, particularly the invasion process, remain obscure. Here, we have unearthed β2 integrin, a crucial member of the integrin family, as an important host factor facilitating Salmonella invasion. It is demonstrated that overexpression of β2 integrin promotes Salmonella invasion, while the knockdown of β2 integrin significantly diminishes the extent of invasion. Moreover, Salmonella exhibits specific binding affinity towards β2 integrin, and the block of β2 integrin on cell surface substantially reduces the infection of cells in vitro. The ectodomain soluble protein of β2 integrin neutralized Salmonella infection both in cells (in vitro) and in mice (in vivo). Additionally, Salmonella protein YrbD directly interacts with β2 integrin to facilitate its invasion. To our knowledge, this study showed for the first time that the protein YrbD mediates Salmonella adhesion and internalization into host cells by interacting with β2 integrin. These findings not only broaden our understanding of the mechanisms underlying Salmonella entry, but also identify a prospective target for therapeutic control.

Innate immunity is dominant in protecting the host's defense against intracellular bacterial infections. The secretion of IL-1β and activation of NLRP3 inflammasome in macrophages play a critical role in combating Mycobacterium tuberculosis (M.tb) infections. M.tb is an extremely successful intracellular pathogen that evades host innate immunity by interfering with a wide range of macrophage functions. However, the precise infection mechanism remains unclear. This study demonstrates that the mycobacterial serine protease Rv2569c interacts with RhoG in macrophages, effectively blocking the NF-κB signaling pathway's initiation and suppressing NLRP3 inflammasome activation, ultimately leading to a decrease in IL-1β secretion and promoting mycobacterial survival within macrophages. To investigate the role of Rv2569c in M.tb infection, an Rv2569c-deficient strain (H37RvΔRv2569c) was used to demonstrate a weakened suppression of the inflammatory response and lower intracellular survival compared to the wild-type (H37Rv) and complemented strain (H37RvΔRv2569c + Rv2569c) through in vitro and in vivo experiments. The findings provide the first proof that RhoG serves as an endogenous host sensor for pathogens and that Rv2569c-RhoG-mediated inflammatory response plays a crucial role in mycobacterial immune evasion.

Mycobacterium avium subsp. paratuberculosis (MAP) causes paratuberculosis (pTB) in ruminants and may be linked to Crohn's disease in humans. Despite extensive MAP genomic data from various animals worldwide, there is a significant lack of such data and understanding of MAP pathogenicity in China. This study used whole-genome sequencing (WGS) and pathogenicity analysis in mice to examine virulence differences among six MAP field strains (designated NM10, LN219, HLJ37, HLJ160, XJ41, and XJ121) isolated from cattle and sheep in various regions of China affected by pTB. The WGS and pan-genome analysis revealed close genomic relatedness among the six MAP strains. However, strains LN219 and NM10 exhibited two and three hypervirulence factors, respectively, while the other four isolated strains each contained only one hypervirulence factor within their specific genomes. Moreover, AlphaFold predictions indicated that the nine amino acid deletions identified in the anti-anti-σ factor of strains LN219 and NM10 led to the lowest binding affinity in the anti-anti-σ factor_anti-σ factor complexes, relative to the other four Chinese strains and the K-10 strain. In addition, bacterial phenotype analyses and in vivo animal experiments have shown that the pathogenicity and virulence of the LN219 and NM10 strains were significantly elevated compared to the other four isolated strains. These factors may partially account for the differences in virulence observed among MAP strains circulating in China. Furthermore, identifying the genes in this bacterium that are associated with critical disease phenotypes can enable targeted functional experiments on these genes, thereby improving control strategies for pTB.

Streptococcus suis serotype 2 is an economically important zoonotic pathogen that causes septicemia, arthritis, and meningitis in pigs and humans. S. suis serotype 2 is responsible for substantial economic losses to the swine industry and poses a serious threat to public health, and accurate and rapid detection is important for the prevention and control of epidemic disease. In this study, we developed a high-fidelity detection and serotyping platform for S. suis serotype 2 based on recombinase polymerase amplification (RPA) and a clustered regularly interspaced short palindromic repeat (CRISPR)-Cas12a system called Cards-SSJ/K. Cards-SSJ had a detection limit of 10 CFU, takes <60 min, and no cross-reaction was found with other S. suis serotypes, closely related Streptococcus spp., or common pig pathogens, and Cards-SSK could differentiate serotype 2 from serotype 1/2. Results from Cards-SSJ and qPCR were equivalent in detecting S. suis serotype 2 in tissue samples. Analysis indicated that despite a relatively high reagent cost compared to PCR and qPCR, Cards-SSJ was less timeconsuming and had low requirements for equipment and personnel. Thus, it is an excellent method for pointof-care detection for S. suis serotype 2.

Epithelial cells function as the primary line of defense against invading pathogens. However, bacterial pathogens possess the ability to compromise this barrier and facilitate the transmigration of bacteria. Nonetheless, the specific molecular mechanism employed by Mycobacterium tuberculosis (M.tb) in this process is not fully understood. Here, we investigated the role of Rv2569c in M.tb translocation by assessing its ability to cleave E-cadherin, a crucial component of cell-cell adhesion junctions that are disrupted during bacterial invasion. By utilizing recombinant Rv2569c expressed in Escherichia coli and subsequently purified through affinity chromatography, we demonstrated that Rv2569c exhibited cell wall-associated serine protease activity. Furthermore, Rv2569c was capable of degrading a range of protein substrates, including casein, fibrinogen, fibronectin, and E-cadherin. We also determined that the optimal conditions for the protease activity of Rv2569c occurred at a temperature of 37°C and a pH of 9.0, in the presence of MgCl2. To investigate the function of Rv2569c in M.tb, a deletion mutant of Rv2569c and its complemented strains were generated and used to infect A549 cells and mice. The results of the A549-cell infection experiments revealed that Rv2569c had the ability to cleave E-cadherin and facilitate the transmigration of M.tb through polarized A549 epithelial cell layers. Furthermore, in vivo infection assays demonstrated that Rv2569c could disrupt E-cadherin, enhance the colonization of M.tb, and induce pathological damage in the lungs of C57BL/6 mice. Collectively, these results strongly suggest that M.tb employs the serine protease Rv2569c to disrupt epithelial defenses and facilitate its systemic dissemination by crossing the epithelial barrier.

Salmonella enterica serovar Typhimurium, the causative agent of gastroenteritis, is one of the most successful intracellular pathogens. Although certain host factors for Salmonella infection have been unveiled, the factors mediating Salmonella entry, particularly the invasion process, remain obscure. Here, we have unearthed β2 integrin, a crucial member of the integrin family, as an important host factor facilitating Salmonella invasion. It demonstrated that overexpression of β2 integrin promotes Salmonella invasion, while the knockdown of β2 integrin significantly diminishes the extent of invasion. Moreover, Salmonella exhibits specific binding affinity towards β2 integrin, and the block of β2 integrin on cell surface substantially reduces the infection of cells in vitro. The ectodomain soluble protein of β2 integrin neutralized Salmonella infection both in cells (in vitro) and in mice (in vivo). Additionally, Salmonella protein YrbD directly interacts with β2 integrin to facilitate its invasion. To our knowledge, this study showed for the first time that the protein YrbD mediates Salmonella adhesion and internalization into host cells by interacting with β2 integrin. These findings not only broaden our understanding of the mechanisms underlying Salmonella entry, but also identify a prospective target for therapeutic control.

Mycobacterium avium subspecies paratuberculosis (MAP) causes paratuberculosis (PTB), which is a granulomatous enteritis in ruminants that threatens the dairy industry’s healthy development and public health safety worldwide. Because the commercial inactivated vaccines are not completely protective and interfere with bovine tuberculosis diagnostics, we tested four fusion proteins, namely 66NC, 66CN, 90NC, and 90CN, which were constructed with MAP3527, Ag85B, and Hsp70 of MAP in different tandem combinations. Notably, 66NC, which encodes a 66 kDa fusion protein that combines in linear order MAP3527 N40–232 , Ag85B 41–330 , and MAP3527 C231–361, induced a powerful and specific IFN-γ response. Immunization of C57BL/6 mice with the 66NC fusion protein formulated in Montanide ISA 61 VG adjuvant generated robust Th1, Th2, and Th17 type immune responses and strong antibody responses. The 66NC vaccine protected C57BL/6 mice against virulent MAP K-10 infection. This resulted in a reduction of bacterial load and improvement of pathological damage in the liver and intestine, in addition to a reduction of body weight loss; significantly better protection than the reported 74 F vaccine was also induced. Furthermore, vaccine efficacy correlated with the levels of IFN-γ-, TNF-α-, and IL-17A-secreting antigen-specific CD4 + and CD8 + T lymphocytes as well as with serum IFN-γ and TNF-α levels after vaccination. These results demonstrate that recombinant protein 66NC is an efficient candidate for further development into a protective vaccine in terms of inducing specific protection against MAP.

本实验室前期研究发现了未见报道的副结核分枝杆菌(MAP)GDSL脂肪酶家族蛋白MAP_2739.为进一步分析MAP_2739的酶学特性,本实验利用生物信息学网站和软件对MAP_2739保守结构域、二级结构、3D同源建模等分析,进一步确认其属于GDSL脂肪酶家族蛋白.以MAP参考株基因组DNA为模板,PCR扩增获得map_2739目的基因约891 bp,克隆于表达载体pET-22b中,构建重组质粒pET-22b-map_2739,转化大肠杆菌感受态细胞,经IPTG诱导表达、蛋白复性、Ni-TNA柱亲和层析纯化后,利用SDS-PAGE分析目的蛋白的表达及纯化效果,并通过western blot鉴定.结果显示,获得了以包涵体形式表达的经复性的纯化重组MAP_2739蛋白(rMAP_2739).利用该蛋白制备兔多克隆抗体,通过ELISA方法检测,多抗血清效价为1∶51 200.经差速离心法分离MAP参考株组分,利用该多克隆抗体为一抗,通过western blot检测,结果显示在细胞壁、细胞膜和细胞浆均出现35 ku的特异性条带,表明MAP_2739为胞外蛋白.以对硝基苯基酯(p-NPs)为底物进行酶活测定,结果显示MAP_2739蛋白为脂肪酶,可水解短链和长链脂肪酸,其最适酶反应pH值为9.0,且rMAP_2739蛋白经巴氏消毒法预处理后,仍具有脂肪酶活性.以重组质粒pET-22b-map_2739为模板,利用各定点突变引物,经PCR扩增各突变的map_2739基因,并测序后转化大肠杆菌感受态细胞,通过western blot鉴定蛋白表达及纯化情况,并进行了酶活测定分析,结果显示获得各定点突变纯化蛋白,确定S46和D204为MAP_2739的酶活性位点.综上所述,本研究首次证明MAP_2739是MAP胞外GDSL脂肪酶,该结果为进一步研究其在MAP致病中的作用机制奠定了基础.

The serine proteases of Mycobacteria tuberculosis (Mtb) are important contributors to the process of bacterial invasion and its pathogenesis. In the present study, we systematically characterized the role of the Rv1043c protein in mycobacterium infection by purifying the Rv1043c protein in Escherichia coli and constructing a Mycobacterium smegmatis (Msg) strain overexpressing Rv1043c (Msg_Rv1043c). We found that Rv1043c had serine protease activity and localized to the surface of Mtb. We determined that the optimal pH and temperature for the Rv1043c serine protease were 9.0 and 45°C, respectively. Moreover, the serine protease activity of Rv1043c was enhanced by divalent metal ions of Ca2+ and Mg2+. Site-directed mutagenesis studies demonstrated that the serine 279 residue in Rv1043c plays a catalytic role. Additionally, mouse model studies confirmed that Rv1043c significantly enhanced the survival of Msg in vivo, induced pulmonary injury and lung cell apoptosis, and promoted the release of pro-inflammatory cytokines interleukin-1β and interleukin-6 in mice. This study presents novel insights into the relationship between mycobacterial serine protease and the pathogenesis of the disease.

为评价猪圆环病毒2型-副猪嗜血杆菌二联亚单位疫苗(以下简称二联苗)对小鼠的免疫保护效果,本研究将猪圆环病毒2型(PCV2)cap基因克隆至pMAL-c5X载体中,并通过原核系统表达了重组Cap蛋白(rCap).通过western blot检测显示原核表达的rCap与PCV2单克隆抗体发生特异性结合,表明rCap具有良好的反应原性.利用本研究室已经纯化并保存的副猪嗜血杆菌(HPS)重组蛋白rCdtB、rAfua和rOPPA,与rCap蛋白以及佐剂ISA201VG混合乳化后制成PCV2-HPS二联亚单位疫苗,疫苗中各蛋白(rCdtB、rAfua、rOPPA、rCap)浓度均为50μg/300μL.将60只6周龄BALB/c小鼠随机均分成免疫组和对照组,采用背部多点注射方式免疫,首免后间隔14d二免.一免后以及二免后的14 d分别通过颌下采血方法采血,通过间接ELISA方法检测各组小鼠血清中的特异性抗体,结果显示,二免后14d,免疫组小鼠血清中CdtB、OPPA、Afua抗体水平分别与PBS+ISA201VG对照组和免疫之前比较均极显著提高(P＜0.0001);利用PCV2免疫过氧化物酶单层试验(IPMA)抗体检测试剂盒检测各组小鼠血清抗体,结果显示在攻毒前PBS组均未检测到PCV2抗体,免疫组二免后14 d抗体水平为1:800.二免后14 d,将免疫组和PBS组各随机分为3组(每组10只小鼠)进行攻毒保护试验,结果显示二联苗对PCV2攻毒组小鼠的免疫保护率为80％,对HPS5型HN10株攻毒组小鼠的免疫保护率为70％,与对照组比较差异极显著(P＜0.01);对HPS13型ZD12株攻毒组小鼠的免疫保护率为80％,与对照组比较差异极显著(P＜0.001).上述结果首次表明,原核表达的rCap具有良好的免疫原性,PCV2-HPS二联亚单位疫苗对小鼠具有一定的保护效果,为后续PCV2-HPS二联亚单位疫苗的研究奠定了实验基础.