The ability of the leishmanial parasite UR6 to act as an immunoprophylactic and immunotherapeutic agent against Leishmania donovani infection in BALB/c mice was investigated. Unlike the virulent L. donovani AG83 (MOHOM/IN/1983/AG83), UR6 given through intracardiac route failed to induce visceral infection, but when it was injected subcutaneously, UR6 induced a short-lived and localized self-healing skin lesion. Priming of peritoneal macrophages with UR6 in vitro induced superoxide (O 2 ؊ ) generation, whereas similar experiments with virulent AG83 inhibited O 2 ؊ generation. It was observed that priming of mice with either live or sonicated UR6 in the absence of any adjuvant provided strong protection against subsequent virulent challenge. Further, UR6-primed infected mice not only displayed a strong antileishmanial delayed-type hypersensitivity (DTH) response but also showed an elevated level of the serum antileishmanial immunoglobulin G2a (IgG2a) isotype, whereas infected mice failed to mount any antileishmanial DTH response and showed an elevated level of IgG1. This indicates that UR6 priming and subsequent L. donovani infection allowed the expansion of Th1 cells. Our studies indicate that UR6 has potential to be used as an immunoprophylactic and immunotherapeutic agent against experimental visceral leishmaniasis.

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The current study was undertaken to correlate post-translational protein modification by methylation with the functionality of enzymes involved in trehalose metabolism in Saccharomyces cerevisiae. Trehalose is an economically important disaccharide providing protection against various kinds of stresses. It also acts as a source of cellular energy by storing glucose. Methyl group donor S-adenosyl L-methionine (AdoMet) and methylation inhibitor-oxidized adenosine (AdOx) were used for the methylation study. AdoMet delayed initial growth of the cells but the overall growth rate remained same suggesting its interference in G1 phase of the cell cycle. Metabolic-altered enzyme activities of acid trehalase (AT), neutral trehalase (NT), and trehalose-6-phosphate synthase (TPS) were observed when treated with AdOx and AdoMet separately. A positive effect of methylation was observed in TPS, hence, it was purified in three different conditions, using AdoMet, AdOx, and control. Differences in mobility of methylated, methylation-inhibited, and control TPS during acidic native gel electrophoresis confirmed the occurrence of induced methylation. Hydrolysis under alkaline pH conditions revealed that methylation of TPS was different than O-methylation. MALDI-TOF analysis of trypsin-digested samples of purified methylated, methylation-inhibited, and control TPS revealed that an increase of 18 Da mass in methylated peptides suggesting the introduction of methyl ester in TPS. Results of amino acid analysis corroborated the presence of methyl cysteine. The data presented here strongly suggests that trehalose production was enhanced due to methylation of TPS arising from carboxymethylation of cysteine residues.

The present investigation was a lectin-based diagnosis of malignant prostate cancer (pC) by the interaction of phytohemagglutinin (pHa lectin) from Phaseolus vulgaris with the glycan part of serum prostate specific antigen (psa) of patients with prostatic disorder. This was confirmed by the interaction between pHa and purified psa obtained from serum by electrophoretic separation and finally by HplC chromatography. The precipitate of carbohydrate content after binding of pHa with purified psa of pC was significantly higher than that of benign prostate hyperplasia (BpH) and/or normal serum psa. The results suggest that there may be a striking difference in glycosylation pattern of psa between BpH and pC. The cut off value ≥ 10 µg/ml of the carbohydrate content of pHa-psa precipitate indicates strong suspicion for pC irrespective of total serum psa cut off level ≥ 4.0ng/ml by conventional immunoassay method and this may be taken as a guideline in differentiating pC and BpH.Key words: prostate cancer, BPH, PSA, lectin. * Corresponding authorThe interest of the sugar specific proteins, lectins, have greatly intensified with the realization that they react with a variety of glycoproteins [1,2]. The interaction takes place between the glycan moiety of glycoproteins and the carbohydrate binding receptors of lectins. The reactions of biomedical glycoprotein markers with lectins were studied as valuable tools for clinical diagnosis [3]. It was observed that pHa lectin (Phaseolus vulgaris), reacts with different serum proteins and glycoproteins [4]. estimation of serum prostate specific antigen (psa) for detection of prostate cancer (pC) is determined by the sensitive immunoassay method. a low serum psa cut-off level of 4.0 ng/ml is used during screening procedure to detect pC at an early stage but an appreciable risk of false positive results was observed with this low cut off value resulting in unnecessary biopsies for those with BpH [5]. some serum psa samples of patients with clinically proven benign prostate hyperplasia (BpH) showed higher value than 4ng/ ml [6] and a few histologically proven pC patients indicated normal serum psa level [7] in immunoassay method. The techniques currently used in immunodetection of serum psa concentration are of limited clinical value in the early detection of pC and its distinction from BpH had already been reported by us [8]. psa is known to be a glycoprotein and preliminary observations indicate that psa binds with pHa.Further,a few studies have discussed the changes in sugar-chain structure of psa associated with malignant transformation [9].Therefore, the present investigation was designed to quick identification of suspected pC by interaction of pHa lectin with the glycan part of serum psa glycoprotein and differentiation of pC from BpH. Patients and methodsChemicals. pHa lectin (phaseolus vulgaris) was purchased from sigma Chemical Co. all other chemicals were of analytical grade.Samples. serum samples of 22 male histologically proven prostate cancer (pC) patients (age between...

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