Expression of GroES TB antigen in tobacco and potato

As the world races towards a plant-based bioeconomy, plants known to be ideal and economical bioreactors are being harnessed for the production of recombinant proteins. The major immunodominant 10 kDa GroES TB antigen (Chaperonin 10) gene from Mycobacterium tuberculosis was selected for expression in plants as a putative tuberculosis (TB) subunit vaccine candidate. Two crops, tobacco and potato, were engineered by stable plant transformation for expression of the 10 kDa GroES TB antigen using non-viral binary vectors. The integration of the GroES TB gene into the genomes of tobacco and potato was confirmed by PCR and Southern blotting. The expression of the GroES TB antigen in tobacco was 0.04–1.2 % of the total soluble protein (TSP). However, the expression of the same TB antigen in the Indian potato cv. Kufri bahar was comparatively low (0.033 % of TSP). The recombinant GroES plant derived protein was characterised and confirmed by MALDI-TOF–TOF and ELISA. This is the first report of the expression of the 10 kDa chaperonin in tobacco and potato.     

Modulation of inducible nitric oxide synthase (iNOS) expression and cardiovascular responses during static exercise following iNOS antagonism within the ventrolateral medulla

Previous reports indicate that inducible nitric oxide synthase (iNOS) blockade within the rostral ventrolateral medulla (RVLM) and caudal ventrolateral medulla (CVLM) differentially modulated cardiovascular responses, medullary glutamate, and GABA concentrations during static skeletal muscle contraction. In the current study, we determined the role of iNOS antagonism within the RVLM and CVLM on cardiovascular responses and iNOS protein expression during the exercise pressor reflex in anesthetized rats. Following 120 min of bilateral microdialysis of a selective iNOS antagonist, aminoguanidine (AGN; 10 µM), into the RVLM, the pressor responses were attenuated by 72 % and changes in heart rate were reduced by 38 % during a static muscle contraction. Furthermore, western blot analysis of iNOS protein abundance within the RVLM revealed a significant attenuation when compared to control animals. In contrast, bilateral administration of AGN (10 µM) into the CVLM augmented the increases in mean arterial pressure by 60 % and potentiated changes in heart rate by 61 % during muscle contractions, but did not alter expression of the iNOS protein within the CVLM. These results demonstrate that iNOS protein expression within the ventrolateral medulla is differentially regulated by iNOS blockade that may, in part, contribute to the modulation of cardiovascular responses during static exercise.     

Transarterial chemoembolization combined with sorafenib for unresectable hepatocellular carcinoma: a systematic review and meta-analysis

Sorafenib in combination with Transarterial chemoembolization (TACE) is increasingly used in patients with unresectable hepatocellular carcinoma (HCC), but the current evidence is still controversial. The aim of this systematic review was to evaluate the effectiveness and safety of TACE plus sorafenib versus TACE alone for unresectable HCC. We searched PubMed, EMBASE and the Cochrane Library for clinical trials comparing TACE plus sorafenib with TACE alone for unresectable HCC. The study outcomes included overall survival (OS), time to progression (TTP), objective response and adverse events (AEs). Six studies including 1,181 patients were included. Meta-analysis of all studies suggested that the combination therapy group had significant longer OS than TACE group [hazard ratio (HR) = 0.64, 95 % confidence interval (CI) = 0.43–0.97], but the pooled HR of randomized controlled trials (RCTs) failed to achieve statistical significance. For TTP, meta-analysis in both RCTs subgroup and retrospective studies subgroup suggested that combination therapy was superior to TACE group. The combination therapy was also associated with better response to treatment (risk ratio = 1.45, 95 % CI = 1.04–2.02) when both RCTs and retrospective studies were pooled. However, the sorafenib associated AEs were more frequent in the combination therapy group. In conclusion, the combination of TACE and sorafenib is likely to improve OS, TTP and response to treatment when compared with TACE monotherapy. The combination group is also associated with more sorafenib-related AEs.     

Protective Mechanism of Panax notoginseng Saponins on Rat Hemorrhagic Shock Model in Recovery Stage

To explore protective mechanism of Panax notoginseng saponins (PNS) on rat hemorrhagic shock model in recovery stage. 72 Wistar rats were selected and divided into control group, model group and PNS group with 24 rats in each group. 200 mg/kg PNS was injected intravenously at 60 min of hemorrhagic shock stage in PNS groups. Changes of endotoxin, MPO, IL-6, SOD, MDA and TNF α were observed at 30 and 120 min of recovery stage by ELISA; water content of lung and intestine was detected; HE staining was applied to observe morphological change of intestinal mucosa, kidney, liver and lung; western blot was used to detect intercellular adhesion molecule-1 (ICAM-1) level in lung tissue and intestine tissue. At 30 min and 120 min of recovery stage, MDA, MPO, endotoxin, TNF α and IL-6 levels significantly increased in model group compared with control group, however SOD level significantly decreased, the difference was statistically significant (P < 0.05); PNS dose-dependently decreased MDA, MPO, endotoxin, TNF α and IL-6 levels, and increased SOD level, which was statistically significant (P < 0.05); In results of water content detection, water content in lung tissue and intestine tissue was significantly higher than in control group, however, after being treated with PNS, the water content was significantly decreased; HE staining showed the morphologic change of lung tissue cells; Western blot showed that in lung tissue and intestine tissue, ICAM-1 level in model group was significantly higher than in control group, and it was lower in PNS group than in model group. PNS can increase SOD activity, decrease levels of MDA, endotoxin and MPO, decrease expression of TNF α and IL-6, and decrease water content in lung tissue and intestine tissue. Thus, PNS is protective to rat hemorrhagic shock model by anti oxidative stress and anti-inflammatory pathways, and ICAM-1 may play an important role in the mechanism.     

Associations of platelet-activating factor acetylhydrolase (PAF-AH) gene polymorphisms with circulating PAF-AH levels and risk of coronary heart disease or blood stasis syndrome in the Chinese Han population

The circulating level of platelet-activating factor acetylhydrolase (PAF-AH) is a novel biomarker to predict the presence of coronary heart disease. PAF-AH gene polymorphisms may be responsible for the variance of circulating PAF-AH levels in individuals. However, the association of PAF-AH gene polymorphisms with circulating PAF-AH levels and the susceptibility to coronary heart disease (CHD) remains unsolved. Blood stasis syndrome (BSS) of CHD is the most common type of TCM syndromes, and a previous study discovered its relationship with the elevated circulating PAF-AH levels. However, the association of gene polymorphisms and CHD with BSS is unclear at present. In this study, four polymorphisms (R92H, I198T, A379V, V279F) of the PAF-AH gene were genotyped in 570 CHD patients, of which 299 had BSS. In addition, 317 unaffected individuals from the same hospitals served as controls. Plasma PAF-AH levels were measured in 155 controls and 271 CHD patients selected randomly, including 139 CHD patients with BSS. In the Chinese Han population, plasma PAF-AH levels in CHD patients with BSS or without BSS were significantly higher (12.9 ± 6.5 and 11.1 ± 5.0 μM, respectively) than in controls (9.3 ± 5.2 μM); this difference still remained significant after adjustment for traditional risk factors or the inflammatory factors. The R92H polymorphism was highly related to the plasma PAF-AH levels and the risk of CHD, especially among patients with BSS, even with the adjustment for the effects of traditional factors. The I198T polymorphism was highly associated with risk of CHD with BSS, but was associated with neither the risk of CHD with no BSS nor with elevated plasma PAF-AH levels.     

Effect of polymorphisms in the CSN3 (κ-casein) gene on milk production traits in Chinese Holstein Cattle

This study was designed to evaluate significant associations between single nucleotide polymorphisms (SNPs) and milk composition and milk production traits in Chinese Holstein cows. Six SNPs were identified in the κ-casein gene using pooled DNA sequencing. The identified SNPs were genotyped by Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) methods from 507 individuals. Out of six, we identified three non-synonymous SNPs (g.10888T>C, g.10924C>A and g.10944A>G) that changed in the protein product. SIFT (Sorting_Intolerant_From_Tolerant) prediction score (0.01) demonstrated that protein changed Isoleucine > Threonine (g.10888T>C) will affect the phenotypes. Significant associations between identified SNPs and three yield traits (milk, protein and fat) and two composition traits (fat and protein percentages) were found whereas it did not reach significance for fat percentage in haplotypes association. Importantly, the significant SNPs in our results showed a large proportion of the phenotypic variation of milk protein yield and concentration. Our results suggest that CSN3 is an important candidate gene that influences milk production traits, and identified polymorphisms and haplotypes could be used as a genetic marker in programs of marker-assisted selection for the genetic improvement of milk production traits in dairy cattle.     

Alpha-Synuclein Oligomerization in Manganese-Induced Nerve Cell Injury in Brain Slices: A Role of NO-Mediated S-Nitrosylation of Protein Disulfide Isomerase

Over-exposure to manganese (Mn) has been known to induce endoplasmic reticulum (ER) stress involving protein misfolding. The proper maturation and folding of native proteins rely on the activity of protein disulfide isomerase (PDI). However, the exact mechanism of Mn-induced alpha-synuclein oligomerization is unclear. To explore whether alpha-synuclein oligomerization was associated with S-nitrosylation of PDI, we made the rat brain slice model of manganism and pretreated slices with l-Canavanine, a selective iNOS inhibitor. After slices were treated with Mn (0, 25, 100, and 400 μM) for 24 h, there were dose-dependent increases in apoptotic percentage of cells, lactate dehydrogenase (LDH) releases, production of NO, inducible nitric oxide synthase (iNOS) activity, the mRNA and protein expressions of iNOS, and PDI. Moreover, S-nitrosylated PDI and alpha-synuclein oligomerization also increased. However, there was a significant increase in the PDI activity of 25-μM Mn-treated slices. Then, PDI activity and the affinity between PDI and alpha-synuclein decreased significantly in response to Mn (100 and 400 μM), which was associated with S-nitrosylation of PDI. The results indicated that S-nitrosylated PDI could affect its activity. We use the l-Canavanine pretreatment brain slices to inhibit S-nitrosylation of PDI. The results showed that l-Canavanine pretreatment could reduce Mn-induced nerve cell injury and alpha-synuclein oligomerization. Additionally, there was a significant recovery in PDI activity in l-Canavanine-pretreated slices. The findings revealed that Mn induced nitrosative stress via the activation of iNOS and subsequent S-nitrosylation of PDI in cultured slices. Moreover, S-nitrosylation of PDI is an important signaling event in the Mn-induced alpha-synuclein oligomerization in brain slices.     

The Rho kinase inhibitor Y-27632 facilitates the differentiation of bone marrow mesenchymal stem cells

The selective in vitro expansion and differentiation of multipotent stem cells are critical steps in cell-based regenerative therapies, but technical challenges have limited cell yield and thus the success of these potential treatments. The Rho GTPases and downstream Rho kinases (Rho coiled-coil kinases or ROCKs) are central regulators of cytoskeletal dynamics during the cell cycle and thus help determine the balance between stem cells self-renewal, lineage commitment, and apoptosis. Here, we examined if suppression of ROCK signaling enhances the efficacy of bone marrow-derived mesenchymal stem cells (BMSCs) differentiation into neurons and neuroglial cells. BMSCs were cultured in epidermal growth factor (EGF, 10 µg/l) and basic fibroblastic growth factor (bFGF, 10 µg/l) in the presence or absence of the Rho kinase inhibitor Y-27632 (10 µM). The expression levels of neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP) were detected by immunofluorescence and Western blotting. The average number of NSE-positive cells increased from 83.20 ± 8.677 (positive ratio 0.2140 ± 0.0119) to 109.20 ± 8.430 (positive ratio 0.3193 ± 0.0161) per visual field in the presence of Y-27632, while GFAP-positive cell number increased from 96.30 ± 8.486 (positive ratio 0.18 ± 0.0152) to 107.50 ± 8.683 (positive ratio 0.27 ± 0.0115) (P < 0.05 for both). Both NSE and GFAP protein expression levels were enhanced significantly by Y-27632 treatment (NSE: 0.74 ± 0.05 vs. 1.03 ± 0.06; GFAP: 0.64 ± 0.08 vs. 0.97 ± 0.05, both P < 0.01) as indicated by Western blots. The Rho kinase inhibitor Y-27632 concomitant with EGF and bFGF stimulation promotes BMSC differentiation into neural cells. Control of Rho kinase activity may enhance the efficiency of stem cell-based treatments for neurodegenerative diseases.     

The amino-terminal sequence ofStreptomyces griseus carboxypeptidase

The amino-terminal sequence of carboxypeptidase fromStreptomyces griseus was determined using a new protocol for automatic Edman degradation that reduced background noise. The sequence of the first 48 residues is: Asp-Phe-Pro-Pro-Ala-Asp-Ser-Arg-Tyr-His-Asn-Tyr-Ala-Glu-Met-Asn-Ala-Ala-Ile-Asp-Ala-Arg-Ile-Ala-Ala-Asn-Pro-Ser-Ile-Met-Ser-Lys-Arg-Val-Ile-Gly-Lys-Thr-Tyr-Gln-Gly-(Arg)-Asp-Val-Ile-Ala-Val-Lys, which is homologous to that of other zinc-containing carboxypeptidase from vertebrate and invertebrate sources.     

Association of vitamin D receptor FokI and ApaI polymorphisms with lung cancer risk in Tunisian population

Many studies reported that Vitamin D Receptor (VDR) gene polymorphisms might influence the cancer risk due to their antiproliferative, antiangiogenic, and apoptotic effects. The aim of this study was to explore the genetic association of VDR polymorphisms with lung cancer risk in Tunisian population. The genotype and haplotype frequencies of four VDR polymorphisms, FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232) and TaqI (rs731236) were studied using polymerase chain reaction and restriction fragment length polymorphism analysis in 240 patients with lung cancer and 280 healthy controls. The distribution of genotype frequencies differed significantly between lung cancer subjects and controls (FokI P _adj  = 0.002; ApaI P _adj  = 0.013). Haplotype analyses revealed a significant association between G-A-C and A-C-T haplotypes and lung cancer risk (P _corr  = 0.0128, P _corr  = 0.008). When patients were stratified according to gender, age, and smoking, significant associations were detected with FokI and TaqI polymorphisms. We found a lack of association between BsmI, TaqI polymorphisms and lung cancer risk (P > 0.05). Only, the attributable proportion due to interaction and the synergic index for interaction between ApaI polymorphism and smoking were statistically significant (P _adj  = 0.74, 95 % CI = 0.38–1.20) and (P _adj  = 0.63, 95 % CI = 0.05–1.21), respectively. Both the additive interaction measures suggested the existence of a biological interaction between SNP ApaI, but not FokI, and smoking. The multiplicative interaction measure was not statistically significant (P > 0.05). This is the first study in Tunisia, which suggested that VDR FokI and ApaI polymorphisms might be risk factors for lung cancer development.     

Immune Response of the VEGF/bFGF Complex Peptide Vaccine and Function of Immune Antibodies in Inhibiting Migration of HUVEC Cells and Proliferation of Cancer Cells

Overexpression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) plays a key role in tumor angiogenesis and metastasis in tumors. VEGF/bFGF complex peptide (VBP3) was designed to elicit the body to produce both high titer anti-VEGF and anti-bFGF antibodies to inhibit tumor angiogenesis and tumor growth. BALB/c mice were immunized with the VEGF/bFGF complex peptide, and the immune responses were assayed. Splenocytes were separated from the immunized mice and the CD4, CD8 T cells and IFN-γ were assayed by Flow cytometry. The results showed that the VBP3 could effectively stimulate immune response in mice and resulted in the increase of CD4 and CD8 T cells. CD4+ T cells and CD8+ T cells were increased from 10.78 to 15.13 and 6.82 to 11.58 % respectively. Polyclonal antibodies purified from the VBP3 immunized mice showed good anti-proliferation function to lung cancer cells, and resulted in the decrease of phosphroylation level of Akt and Erk assayed by the Western-blot. Transwell assays showed that the migration of HUVEC cells was inhibited by the antibodies. The results revealed that the VBP3 have good immunogenicity and may be used as a vaccine for tumor therapy.     

Selenium Deficiency Influences the Gene Expressions of Heat Shock Proteins and Nitric Oxide Levels in Neutrophils of Broilers

The aim of the present study was to investigate the effects of selenium (Se) deficiency on the expressions of heat shock proteins (Hsp90, 70, 60, 40, and 27) and nitric oxide (NO) levels in neutrophils of broilers. One hundred eighty 1-day-old broilers were randomly assigned into two groups and were fed on a low-Se diet (0.008 mg/kg Se) or a control diet (0.2 mg/kg Se), respectively. Then, the messenger RNA (mRNA) levels of Hsp90, 70, 60, 40, and 27, induced nitric oxide synthase (iNOS), and NO levels were examined. The results showed that Se deficiency increased the mRNA levels of Hsps and iNOS and induced higher level of NO in chicken neutrophils (P?iNOS had the biggest correlation with Hsp60, which indicated that Hsp60 might play an important function in inhibiting the production of NO, and the correlation coefficient between Hsp60 and Hsp70 was over 0.9, which indicated that they might have a synergistic effect. These results suggested that the level of NO and Hsp expression levels in neutrophils can be influenced by Se deficiency. And Hsp40 might play the crucial protective role in neutrophils induced by Se deficiency.     

A prepared anti-MSTN polyclonal antibody reverses insulin resistance of diet-induced obese rats via regulation of PI3K/Akt/mTOR&FoxO1 signal pathways

Suppression of myostatin (MSTN) is associated with skeletal muscle atrophy and insulin resistance. However, the mechanisms by which MSTN regulates insulin resistance are not well known. We have explored the signaling pathways through which MSTN regulates insulin resistance in diet-induced obese rats using a polyclonal antibody for MSTN. The anti-MSTN polyclonal antibody significantly improved insulin resistance and whole-body insulin sensitivity, decreased MSTN protein expression in muscle samples by 39 % in diet-induced obese rats. Furthermore, the anti-MSTN polyclonal antibody significantly enhanced PI3K activity (140 %), Akt phosphorylation (86 %), GLUT4 protein expression (23 %), the phosphorylation of mTOR (21 %), and inhibited the phosphorylation of FoxO1 (57 %), but did not affect the phosphorylation of GSK-3β. Thus, suppression of MSTN by the anti-MSTN polyclonal antibody reverses insulin resistance of diet-induced obesity via MSTN/PI3K/Akt/mTOR and MSTN/PI3K/Akt/FoxO1 signaling pathways.     

Apparent Reduction of ADAM10 in Scrapie-Infected Cultured Cells and in the Brains of Scrapie-Infected Rodents

It has been described that A disintegrin and metalloproteinase (ADAM10) may involve in the physiopathology of prion diseases, but the direct molecular basis still remains unsolved. In this study, we confirmed that ADAM10 was able to cleave recombinant human prion protein in vitro. Using immunoprecipitation tests (IP) and immunofluorescent assays (IFA), reliable molecular interaction between the native cellular form of PrP (PrP^C) and ADAM10 was observed not only in various cultured neuronal cell lines but also in brain homogenates of healthy hamsters and mice. Only mature ADAM10 (after removal of its prodomain) molecules showed the binding activity with the native PrP^C. Remarkably more prion protein (PrP)-ADAM10 complexes were detected in the membrane fraction of cultured cells. In the scrapie-infected SMB cell model, the endogenous ADAM10 levels, especially the mature ADAM10, were significantly decreased in the fraction of cell membrane. IP and IFA tests of prion-infected SMB-S15 cells confirmed no detectable PrP-ADAM10 complex in the cellular lysates and PrP-ADAM10 co-localization on the cell surface. Furthermore, we demonstrated that the levels of ADAM10 in the brain homogenates of scrapie agent 263K-infected hamsters and agent ME7-infected mice were also almost diminished at the terminal stage, showing time-dependent decreases during the incubation period. Our data here provide the solid molecular basis for the endoproteolysis of ADAM10 on PrP molecules and interaction between ADAM10 and PrP^C. Obvious loss of ADAM10 during prion infection in vitro and in vivo highlights that ADAM10 may play essential pathophysiological roles in prion replication and accumulation.     

Association between Fok I vitamin D receptor gene (VDR) polymorphism and impulsivity in alcohol-dependent patients

Vitamin D appears to have an important role in the modulation of the central nervous system. Vitamin D exerts its biological effects through its interaction with the vitamin D receptor (VDR). Located on chromosome 12 (12q13.1), the VDR gene has many different polymorphisms. Some of them are known to affect the VDR function, such as FokI (rs2228570, T/C) single nucleotide polymorphism. We aimed to explore a potential relationship between FokI VDR polymorphism and impulsiveness in alcohol-dependent (AD) patients. The study population consisted of 148 patients diagnosed with alcohol dependence (DSM-IV criteria) and 212 healthy controls. DNA was extracted from whole blood samples using the standard procedure. Genotypes were analyzed using a real-time PCR method. We found that FokI VDR gene polymorphism was associated with impulsivity [Barratt Impulsiveness Scale (BIS)-11 total score; P = 0.014], and with attentional impulsivity (BIS-11 subscale; P = 0.002) in the male AD patients. Our results suggest that CC FokI genotype of the VDR gene is associated with a higher level of impulsivity in these patients. This finding supports the hypothesis that impulsiveness, which significantly contributes to development of alcohol dependence, has a genetic background.     

Inhibition of the JAK/STAT pathway with ruxolitinib overcomes cisplatin resistance in non-small-cell lung cancer NSCLC

This study was aimed to elucidate the roles of inhibition of related JAK/STAT pathways in regulating cytotoxicity induced by cisplatin in non-small-cell lung cancer (NSCLC) cell. We treated five non-small-cell lung cancer cell lines with cisplatin alone or with cisplatin and Jak2 inhibitor (ruxolitinib) and assessed cell viability, expression of Jak2 and STAT3 and cell apoptosis. We also investigated the effect of combination treatment inhibited tumor xenograft growth in two human NSCLC xenograft models bearing the cisplatin resistant (H1299) and sensitive (A549) cells. Different cell lines with different genetic background showed half-maximal inhibitory concentrations (IC₅₀) of cisplatin from 4.66 to 68.28 µmol/L. They could be divided into cisplatin intrinsic resistant and cisplatin sensitive cell lines. In cisplatin-resistant cells with higher Jak2 and STAT3 expression, cisplatin and ruxolitinib combination dramatically suppressed the cell growth, down-regulated the expression of phosphorylated STAT3 and induced cleaved caspase-3 expression. Moreover combination with cisplatin and ruxolitinib also significantly inhibited the growth of resistant cell H1299, A549/DDP and H2347 in soft agar model. Finally, combination group significant inhibited the tumor growth and induced the caspase-3 expression compared with either single agent alone (P < 0.05) on the resistant cell xenografts model. The present study indicates that further study is warranted to determine the effectiveness of combination treatment with cisplatin and Jak2/stat3 pathway inhibitor for platinum-resistant NSCLC.     

Paenibacillus nicotianae sp. nov., isolated from a tobacco sample

A Gram-stain positive, facultative anaerobic endospore-forming bacterium, designated strain YIM h-19^T, was isolated from a tobacco sample. Cells were observed to be motile rods by means of peritrichous flagella and colonies were observed to be convex, yellow, circular and showed catalase-positive and oxidase-negative reactions. Strain YIM h-19^T was able to grow at 4–45 °C, pH 6.0–8.0 and 0–3 % NaCl (w/v). The predominant respiratory quinone was identified as MK-7. Major fatty acids were identified as anteiso-C_15:0, anteiso-C_17:0 and C_16:0. The polar lipids were found to be phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and two unidentified polar lipids. The genomic DNA G+C content was determined to be 54 mol%. 16S rRNA gene sequence analysis showed the strain YIM h-19^T was most closely related to Paenibacillus hordei RH-N24^T and Paenibacillus hunanensis FeL05^T with similarities of 98.30 and 94.64 % respectively. However, DNA–DNA hybridization data indicated that the isolate represented a novel genomic species with the genus Paenibacillus. All data from genotypic and phenotypic analyses support the conclusion that strain YIM h-19^T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus nicotianae sp. nov. is proposed. The type strain is YIM h-19^T (=CGMCC1.12819^T = NRRL B-59112^T).     

Recognition of flavin mononucleotide,Haemophilus influenzae type b and its capsular polysaccharide vaccines by antibodies specific to D-ribitol-5-phosphate

D-Ribitol-5-phosphate (Rbt-5-P) is an important metabolite in the pentose phosphate pathway and an integral part of bacterial cell wall polysaccharides, specifically as polyribosyl ribitol phosphate (PRP) in Haemophilus influenzae type b (Hib). The major objective of this study was to investigate whether an antibody specific to Rbt-5-P can recognize the PRP of Hib. D-Ribose-5-phosphate was reacted with proteins in the presence of sodium cyanoborohydride to obtain Rbt-5-P epitopes; 120 h reaction resulted in conjugation of ~30 and ~17 moles of Rbt-5-P/mole of BSA and OVA, respectively, based on decrease in amino groups, MALDI–TOF analyses, an increase in apparent molecular weight (SDS–PAGE) and glycoprotein staining. Immunization of rabbits with Rbt-5-P–BSA conjugate generated antibodies to Rbt-5-P as demonstrated by dot immunoblot and non-competitive ELISA. Homogeneous Rbt-5-P-specific antibody was purified from Rbt-5-P–BSA antiserum subjected to caprylic acid precipitation followed by hapten–affinity chromatography; its affinity constant is 7.1?×?10⁸ M^?1. Rbt-5-P antibody showed 100 % specificity to Rbt-5-P, ~230 %, 10 % and 3.4 % cross-reactivity to FMN, riboflavin and FAD, respectively; the antibody showed ~4 % cross-reactivity to D-ribitol and <3 % to other sugars/sugar alcohols. Rbt-5-P–specific antibody recognized Hib conjugate vaccines containing PRP which was inhibited specifically by Rbt-5-P, and also detected Hib cell-surface capsular polysaccharides by immunofluorescence. In conclusion, Rbt-5-P–protein conjugate used as an immunogen elicited antibodies binding to an epitope also present in PRP and Hib bacteria. Rbt-5-P–specific antibody has potential applications in the detection and quantification of free/bound Rbt-5-P and FMN as well as immunological recognition of Hib bacteria and its capsular polysaccharide.