Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Further development of haematopoietic stem cell (HSC) gene therapy will depend on enhancement of gene transfer safety: ad hoc improvement of vector design relating to each particular disease is thus a crucial issue for HSC gene therapy.... more
Further development of haematopoietic stem cell (HSC) gene therapy will depend on enhancement of gene transfer safety: ad hoc improvement of vector design relating to each particular disease is thus a crucial issue for HSC gene therapy. We modified a previously described lentiviral vector by adding the Emumar B-specific enhancer to a human CD19 promoter-derived sequence (Mol Ther 2004;10:45-56). We thus significantly improved the level of expression of the green fluorescent protein (GFP) reporter gene while retaining the specificity of expression in B-cell progeny of transduced human CD34+ progenitor cells obtained from cord blood or adult bone marrow. Indeed, GFP was strongly expressed from early medullary pro-B cells to splenic mature B cells whereas transgene expression remained low in transduced immature progenitors as in myeloid and T-lymphoid progeny retrieved from xenografted NOD/SCID/gammac(null) mice. Using this lentiviral vector, we further demonstrated the possibility to express a functional human BTK protein in long-term human CD34+ cell B-lymphoid progeny. This newly designed lentiviral vector fulfils one of the pre-requisites for the development of efficient and safe gene therapy for X-linked agammaglobulinaemia, the most common primary humoral immunodeficiency disorder.
Stimulation of the human T-cell line, Jurkat, by a monoclonal antibody (mAb) directed against the CD28 molecule leads to sustained increases in intracellular levels of Ca2+ ([Ca2+]i); the initial rise in Ca2+ comes from internal stores,... more
Stimulation of the human T-cell line, Jurkat, by a monoclonal antibody (mAb) directed against the CD28 molecule leads to sustained increases in intracellular levels of Ca2+ ([Ca2+]i); the initial rise in Ca2+ comes from internal stores, followed by Ca2+ entry into the cells. The CD28 molecule also appears to activate polyphosphoinositide (InsPL)-specific phospholipase C (PLC) activity in Jurkat cells, as demonstrated by PtdInsP2 breakdown, InsP3 and 1,2-diacylglycerol generation and PtdIns resynthesis. We also observed that interleukin-2 (IL2) production induced via CD28 triggering was sensitive to a selective protein kinase C inhibitor. Of the four other anti-CD28 mAbs (CD28.2, CD28.4, CD28.5, CD28.6) tested, only one (CD28.5) was unable to generate any InsPL-specific PLC or IL2 secretion. However, the cross-linking of cell-bound CD28.5 with anti-mouse Ig antibodies led to an increase in [Ca2+]i. CD28-molecule clustering in itself appears to be a sufficient signal for induction of PLC activity.
Background: Sporothrix schenckii and associated species are agents of human and animal sporotrichosis that cause large sapronoses and zoonoses worldwide. Epidemiological surveillance has highlighted an overwhelming occurrence of the... more
Background: Sporothrix schenckii and associated species are agents of human and animal sporotrichosis that cause large sapronoses and zoonoses worldwide. Epidemiological surveillance has highlighted an overwhelming occurrence of the highly pathogenic fungus Sporothrix brasiliensis during feline outbreaks, leading to massive transmissions to humans. Early diagnosis of feline sporotrichosis by demonstrating the presence of a surrogate marker of infection can have a key role for selecting appropriate disease control measures and minimizing zoonotic transmission to humans. Methodology: We explored the presence and diversity of serum antibodies (IgG) specific against Sporothrix antigens in cats with sporotrichosis and evaluated the utility of these antibodies for serodiagnosis. Antigen profiling included protein extracts from the closest known relatives S. brasiliensis and S. schenckii. Enzyme-linked immunosorbent assays and immunoblotting enabled us to characterize the major antigens of feline sporotrichosis from sera from cats with sporotrichosis (n = 49), healthy cats (n = 19), and cats with other diseases (n = 20). Principal Findings: Enzyme-linked immunosorbent assay-based quantitation of anti-Sporothrix IgG exhibited high sensitivity and specificity in cats with sporotrichosis (area under the curve, 1.0; 95% confidence interval, 0.94–1; P<0.0001) versus controls. The two sets of Sporothrix antigens were remarkably cross-reactive, supporting the hypothesis that antigenic epitopes may be conserved among closely related agents. One-dimensional immunoblotting indicated that 3-carboxymuconate cyclase (a 60-kDa protein in S. brasiliensis and a 70-kDa protein in S. schenckii) is the immunodominant antigen in feline sporotrichosis. Two-dimensional immunoblotting revealed six IgG-reactive isoforms of gp60 in the S. brasiliensis proteome, similar to the humoral response found in human sporotrichosis. Conclusions: A convergent IgG-response in various hosts (mice, cats, and humans) has important implications for our understanding of the coevolution of Sporothrix and its warm-blooded hosts. We propose that 3-carboxymuconate cyclase has potential for the serological diagnosis of sporotrichosis and as target for the development of an effective multi-species vaccine against sporotrichosis in animals and humans.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Effect of curcumin on biofilm formation Ritesh Ranajn¹#, Prof. Dipshikha Chakravortty² 1. Summer Research fellow, Indian Academy of science Bangalore, Sri Venkateswara College, Delhi University 2. Indian Institute of Science,... more
Effect of curcumin on biofilm formation
Ritesh Ranajn¹#, Prof. Dipshikha Chakravortty²
1. Summer Research fellow, Indian Academy of science Bangalore, Sri Venkateswara College, Delhi University 2. Indian Institute of Science, Bangalore
                          # Email: tiwariritesh3210070@gmail.com
Salmonella has ability to form biofilms on biotic or abiotic surfaces. The objective of this study was to determine the effect of curcumin on biofilm formation of Salmonella typhymurium (STM) bacteria. The assay was done by biofilm formation in microtiter plate and Growth of STM cells with curcumin or without curcumin in Luria-Bertani broth of 72 h incubation. Incubate STM bacterial strain was shown biofilm in LB tube. Growth of STM with curcumin or without curcumin is demonstrate about curcumin affects only biofilm formation.  The observation of biofilm was taken by removing planktonic cells of microtiter plate then after crystal violet staining at 595 nm in ELISA READER. Growth curve assay demonstrate that curcumin does not affect bacterial growth its only affect the biofilm formation.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
A total of 150 female Swiss mice were used to study the ability of water soluble propolis derivatives (WSPD) of Egyptian propolis to inhibit the proliferation and growth of Ehrlich ascites carcinoma (EAC) cells in mice. The mice were... more
A total of 150 female Swiss mice were used to study the ability of water soluble propolis derivatives (WSPD) of Egyptian propolis to inhibit the proliferation and growth of Ehrlich ascites carcinoma (EAC) cells in mice. The mice were divided equally into three groups: the first was kept as a negative control group, the second received an intraperitoneal injection of 2.5 × 106 EAC and was kept as a positive control group and the third an intraperitoneal injection of 2.5 × 106 EAC and treated with propolis (50 mg/kg body weight) administered by gastric intubations 2 h prior to the intraperitoneal injection of EAC. The propolis was administered daily for 11 successive days. An examination of EAC cells revealed a reduction in the volume, total cell count, viable percentage and increase in the percentage of dead cells in the treated group with an increasing mean survival time (MST), increasing life span (ILS) percentage and treated vs positive control (T/C) percentage. Immunological studies revealed a significant increase in the lymphocyte transformation rate (LTR), phagocytic activity and killing power in the group treated with propolis. A haematological study of the parameters revealed leucocytosis in cancer-bearing mice and propolis-treated groups with granulocytosis and monocytosis. The erythrogram revealed a significant reduction in red blood cell (RBC) count in group 2. The result showed that the implantation of EAC in Swiss mice without treatment resulted in a significant decrease in total protein and albumin levels without a change in globulin level and a significant increase in creatinine level, while the third group that received propolis showed an improvement in these biochemical parameters compared to the normal control group.
Research Interests:
ABSTRACT: The present study compares 13 physiological and immunological variables between a group of healthy Panulirus argus lobsters and a group of lobsters naturally infected with Panulirus argus Virus 1 (PaV1). Viral infection was... more
ABSTRACT: The present study compares 13 physiological and immunological variables between
a group of healthy Panulirus argus lobsters and a group of lobsters naturally infected with Panulirus
argus Virus 1 (PaV1). Viral infection was determined through histopathology and PCR. Ten
of the 13 variables differed significantly between the 2 groups. Using these variables, a principal
component analysis yielded 2 separate clusters: one corresponding to the healthy group and the
other corresponding to the infected group. In particular, infected lobsters exhibited significantly
lower levels of osmotic pressure, total hemocyte counts, plasmatic proteins, and total phenoloxidase
(PO) activity in plasma, as well as significantly higher levels of cholesterol and acylglycerides.
These features are consistent with metabolic wasting, hyperlipidemia, and presumed
immune suppression. Infection with PaV1 appears to increase the susceptibility of lobsters to some
other opportunistic pathogens, as 61.1% of infected lobsters presented infestations of ciliate
epibionts (Epystilis and Zoothamniun) in the gill chamber compared with 11.5% lobsters in the
healthy group. Infected lobsters also showed significantly higher levels of total PO activity in
degranulated hemocytes and trypsin inhibitor activity, potentially indicating activation of immune
response by the PO system during the systemic infection with PaV1.
Research Interests:
Research Interests:
Academia © 2015