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1.
Immunity ; 51(2): 337-350.e7, 2019 08 20.
Article in English | MEDLINE | ID: mdl-31375460

ABSTRACT

Class-switch recombination (CSR) is a DNA recombination process that replaces the immunoglobulin (Ig) constant region for the isotype that can best protect against the pathogen. Dysregulation of CSR can cause self-reactive BCRs and B cell lymphomas; understanding the timing and location of CSR is therefore important. Although CSR commences upon T cell priming, it is generally considered a hallmark of germinal centers (GCs). Here, we have used multiple approaches to show that CSR is triggered prior to differentiation into GC B cells or plasmablasts and is greatly diminished in GCs. Despite finding a small percentage of GC B cells expressing germline transcripts, phylogenetic trees of GC BCRs from secondary lymphoid organs revealed that the vast majority of CSR events occurred prior to the onset of somatic hypermutation. As such, we have demonstrated the existence of IgM-dominated GCs, which are unlikely to occur under the assumption of ongoing switching.


Subject(s)
B-Lymphocytes/immunology , Germinal Center/immunology , Immunoglobulin Class Switching , Plasma Cells/immunology , Plasmablastic Lymphoma/immunology , T-Lymphocytes, Helper-Inducer/immunology , Animals , Cell Differentiation , Cells, Cultured , Humans , Mice , Mice, Inbred C57BL , Phylogeny , Receptors, Antigen, B-Cell/metabolism
2.
Nature ; 547(7663): 318-323, 2017 07 20.
Article in English | MEDLINE | ID: mdl-28700579

ABSTRACT

Protective high-affinity antibody responses depend on competitive selection of B cells carrying somatically mutated B-cell receptors by follicular helper T (TFH) cells in germinal centres. The rapid T-B-cell interactions that occur during this process are reminiscent of neural synaptic transmission pathways. Here we show that a proportion of human TFH cells contain dense-core granules marked by chromogranin B, which are normally found in neuronal presynaptic terminals storing catecholamines such as dopamine. TFH cells produce high amounts of dopamine and release it upon cognate interaction with B cells. Dopamine causes rapid translocation of intracellular ICOSL (inducible T-cell co-stimulator ligand, also known as ICOSLG) to the B-cell surface, which enhances accumulation of CD40L and chromogranin B granules at the human TFH cell synapse and increases the synapse area. Mathematical modelling suggests that faster dopamine-induced T-B-cell interactions increase total germinal centre output and accelerate it by days. Delivery of neurotransmitters across the T-B-cell synapse may be advantageous in the face of infection.


Subject(s)
B-Lymphocytes/immunology , Dopamine/metabolism , Germinal Center/immunology , Immunological Synapses/immunology , T-Lymphocytes, Helper-Inducer/immunology , T-Lymphocytes, Helper-Inducer/metabolism , Animals , B-Lymphocytes/cytology , B-Lymphocytes/metabolism , CD40 Ligand/metabolism , Child , Chromogranin B/metabolism , Female , Germinal Center/cytology , Humans , Inducible T-Cell Co-Stimulator Ligand/metabolism , Mice , Models, Immunological , Neurotransmitter Agents/metabolism , Secretory Vesicles/metabolism , T-Lymphocytes, Helper-Inducer/cytology , Up-Regulation
3.
Exp Cell Res ; 356(1): 48-56, 2017 07 01.
Article in English | MEDLINE | ID: mdl-28408319

ABSTRACT

Dysplastic hepatocytes (DH) represent altered hepatocytes with potential for malignant transformation. To date, most research on pathways to hepatocarcinogenesis has focused on use of "hepatoma" cell lines derived from hepatocellular carcinoma (HCC). We describe a novel technique for deriving/culturing DH and demonstrate their utility for functional studies in vitro, compared to primary hepatocytes (PH) and HCC. PH and DH were prepared by portal vein collagenase perfusion from C57BL/6J mice. DH were subsequently subjected to FACS. HCC from diethylnitrosamine (DEN)-injected mice were mechanically isolated. Cell cycle analyses were performed by flow cytometry and PCNA immunohistochemistry. To establish utility of DH, we studied pathways of p53 turnover, apoptosis and cell proliferation using pfithrin-α (PFT) and nutlin-3. Like PH, DH were minimally proliferative compared to HCC. Only 30±0.03% of DH were in G2/M phase versus 51±0.01% of HCC; this difference corroborated with PCNA-immunostaining of dysplastic nodules from DEN-injected mice. In DH and HCC, nutlin-3 suppressed p53 mRNA, induced p53 and mdm2 activation but paradoxically resulted in increased anti-apoptotic and proliferative activity. Primary murine DH display distinctive biological characteristics compared with PH and HCC. As an intermediate cell type to HCC, they offer a new pathobiologically relevant primary cell culture system with which to interrogate the molecular changes in hepatocarcinogenesis.


Subject(s)
Carcinoma, Hepatocellular/pathology , Cell Transformation, Neoplastic/pathology , Hepatocytes/pathology , Liver Neoplasms, Experimental/pathology , Liver/pathology , Animals , Apoptosis/genetics , Cell Cycle/physiology , Cell Proliferation/genetics , Cells, Cultured , Diethylnitrosamine , Enzyme Activation , Imidazoles/pharmacology , Liver/cytology , Male , Mice , Mice, Inbred C57BL , Piperazines/pharmacology , Proto-Oncogene Proteins c-mdm2/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
4.
Softw Pract Exp ; 52(4): 868-886, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34538962

ABSTRACT

Since the end of 2019, computed tomography (CT) images have been used as an important substitute for the time-consuming Reverse Transcriptase polymerase chain reaction (RT-PCR) test; a new coronavirus 2019 (COVID-19) disease has been detected and has quickly spread through many countries across the world. Medical imaging such as computed tomography provides great potential due to growing skepticism toward the sensitivity of RT-PCR as a screening tool. For this purpose, automated image segmentation is highly desired for a clinical decision aid and disease monitoring. However, there is limited publicly accessible COVID-19 image knowledge, leading to the overfitting of conventional approaches. To address this issue, the present paper focuses on data augmentation techniques to create synthetic data. Further, a framework has been proposed using WoT and traditional U-Net with EfficientNet B0 to segment the COVID Radiopedia and Medseg datasets automatically. The framework achieves an F-score of 0.96, which is best among state-of-the-art methods. The performance of the proposed framework also computed using Sensitivity, Specificity, and Dice-coefficient, achieves 84.5%, 93.9%, and 65.0%, respectively. Finally, the proposed work is validated using three quality of service (QoS) parameters such as server latency, response time, and network latency which improves the performance by 8%, 7%, and 10%, respectively.

5.
Front Microbiol ; 13: 923256, 2022.
Article in English | MEDLINE | ID: mdl-35923397

ABSTRACT

The exact function(s) of the lagovirus non-structural protein p23 is unknown as robust cell culture systems for the Rabbit haemorrhagic disease virus (RHDV) and other lagoviruses have not been established. Instead, a range of in vitro and in silico models have been used to study p23, revealing that p23 oligomerizes, accumulates in the cytoplasm, and possesses a conserved C-terminal region with two amphipathic helices. Furthermore, the positional homologs of p23 in other caliciviruses have been shown to possess viroporin activity. Here, we report on the mechanistic details of p23 oligomerization. Site-directed mutagenesis revealed the importance of an N-terminal cysteine for dimerization. Furthermore, we identified cellular interactors of p23 using stable isotope labeling with amino acids in cell culture (SILAC)-based proteomics; heat shock proteins Hsp70 and 110 interact with p23 in transfected cells, suggesting that they 'chaperone' p23 proteins before their integration into cellular membranes. We investigated changes to the global transcriptome and proteome that occurred in infected rabbit liver tissue and observed changes to the misfolded protein response, calcium signaling, and the regulation of the endoplasmic reticulum (ER) network. Finally, flow cytometry studies indicate slightly elevated calcium concentrations in the cytoplasm of p23-transfected cells. Taken together, accumulating evidence suggests that p23 is a viroporin that might form calcium-conducting channels in the ER membranes.

6.
J Infect Dis ; 202(7): 1059-67, 2010 Oct 01.
Article in English | MEDLINE | ID: mdl-20795820

ABSTRACT

Although immune responses against group A streptococci and the heart have been correlated with antibodies and T cell responses against cardiac myosin, there is no unifying hypothesis about carditis caused globally by many different serotypes. Our study identified disease-specific epitopes of human cardiac myosin in the development of rheumatic carditis in humans. We found that immune responses to cardiac myosin were similar in rheumatic carditis among a small sample of worldwide populations, in which immunoglobulin G targeted human cardiac myosin epitopes in the S2 subfragment hinge region within S2 peptides containing amino acid residues 842-992 and 1164-1272. An analysis of rheumatic carditis in a Pacific Islander family confirmed the presence of potential rheumatogenic epitopes in the S2 region of human cardiac myosin. Our report suggests that cardiac myosin epitopes in rheumatic carditis target the S2 region of cardiac myosin and are similar among populations with rheumatic carditis worldwide, regardless of the infecting group A streptococcal M serotype.


Subject(s)
Cardiac Myosins/immunology , Rheumatic Heart Disease/immunology , Streptococcus pyogenes/immunology , Child , Child, Preschool , Epitope Mapping , Epitopes/immunology , Female , Humans , Immunoglobulin G/immunology , Male
7.
Front Plant Sci ; 11: 288, 2020.
Article in English | MEDLINE | ID: mdl-32256511

ABSTRACT

Traditional functional genetic studies in crops are time consuming, complicated and cannot be readily scaled up. The reason is that mutant or transformed crops need to be generated to study the effect of gene modifications on specific traits of interest. However, many crop species have a complex genome and a long generation time. As a result, it usually takes several months to over a year to obtain desired mutants or transgenic plants, which represents a significant bottleneck in the development of new crop varieties. To overcome this major issue, we are currently establishing a versatile plant genetic screening platform, amenable to high throughput screening in almost any crop species, with a unique workflow. This platform combines protoplast transformation and fluorescence activated cell sorting. Here we show that tobacco protoplasts can accumulate high levels of lipid if transiently transformed with genes involved in lipid biosynthesis and can be sorted based on lipid content. Hence, protoplasts can be used as a predictive tool for plant lipid engineering. Using this newly established strategy, we demonstrate the major role of ABI3 in plant lipid accumulation. We anticipate that this workflow can be applied to numerous highly valuable metabolic traits other than storage lipid accumulation. This new strategy represents a significant step toward screening complex genetic libraries, in a single experiment and in a matter of days, as opposed to years by conventional means.

8.
Pediatr Hematol Oncol ; 23(4): 299-305, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16621771

ABSTRACT

The authors attempted to establish the benefits of flow cytometry-based reticulocyte analysis over absolute neutrophil count (ANC) recovery. Serial hemograms of 18 pediatric cases of hematologic malignancies were analyzed until day 35 of chemotherapy. Immature reticulocyte fraction (IRF) showed early recovery in 44.4% of cases compared to ANC. Since reticulocyte fractions are not influenced by infections, they are a better parameter of bone marrow regeneration than ANC. The study shows that IRF can act as a harbinger of regenerating bone marrow activity in patients with persistent neutropenia and guide the modulation of antibiotic strategies in these patients.


Subject(s)
Bone Marrow/physiology , Hematologic Neoplasms/pathology , Regeneration , Reticulocytes/cytology , Adult , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Blood Cell Count , Female , Flow Cytometry , Hematologic Neoplasms/complications , Hematologic Neoplasms/drug therapy , Humans , Kinetics , Male , Neutropenia , Neutrophils/cytology , Predictive Value of Tests
9.
Clin Infect Dis ; 40(1): 46-51, 2005 Jan 01.
Article in English | MEDLINE | ID: mdl-15614691

ABSTRACT

BACKGROUND: Concern about the emergence of antibiotic-resistant strains and about morbidity and/or mortality related to rheumatic fever and rheumatic heart disease has been a continuous impetus for the development of a safe, effective vaccine against group A Streptococcus (GAS). To date, >120 GAS M types are known, as identified by serological typing. In general, serum immunoglobulin G directed to the hypervariable NH2 terminal portion of M protein leads to complement fixation and opsonophagocytosis of the homologous streptococcal serotype by polymorphonuclear leukocytes, and the protection is type specific. The sequence variation at the N terminus ultimately affects the binding of opsonic antibodies. Because of hypervariability in these opsonic sequences from different M types, it was relevant to use epitopes derived from these multiple sequences in a "multivalent vaccine" design for evaluation of protection against these M types of GAS. Thus, any attempts to design vaccines for a given community will require information on N terminal-sequence typing and variation. METHODS: In the present study, we performed molecular characterization of isolates recovered from patients in northern India--to our knowledge, for the first time--in an attempt to study the circulating M types and their N terminal sequence variability. RESULTS: We report tremendous diversity in GAS strains recovered from symptomatic patients, with implications on the design of appropriate vaccines. Fifty-nine isolates represented 33 different sequence types. Very few novel types and no predominant clones were found. CONCLUSIONS: The high diversity of emm types encountered in a single year suggests that any M protein-based multivalent vaccine would have to be specifically tailored for this region.


Subject(s)
Bacterial Vaccines/administration & dosage , Genetic Variation , Streptococcal Infections/prevention & control , Streptococcus/classification , Bacterial Typing Techniques , Genes, Bacterial , Humans , India , Population Groups , Streptococcus/genetics , Vaccines, Synthetic/administration & dosage
10.
Res Microbiol ; 156(4): 575-82, 2005 May.
Article in English | MEDLINE | ID: mdl-15862457

ABSTRACT

The development of a group A streptococcal (GAS) vaccine has focused on the M protein, a major virulence factor. Antibodies against the amino terminal domain of the M protein are generally protective but only provide type-specific immunity. J14, a 29-mer peptide sequence which contains a conserved epitope from the C-repeat region of the M protein, offers the possibility of a vaccine which will elicit protective opsonic antibodies against multiple GAS strains. In this study we have shown that antibodies raised against J14 are capable of opsonising 37 GAS isolates representing different emm types derived from a region in which GAS infection is endemic. We also demonstrate that J14 antisera is capable of opsonising GAS isolates containing J14 homologues but not J14-specific sequences, further increasing the strain coverage of this vaccine candidate. Isolates with three C-repeats were opsonised more efficiently than isolates with two repeats. Opsonisation of a strain with only a single C-repeat was dramatically lower than other strains tested. The number of C-repeats present in the M protein of individual isolates therefore appears to be the critical factor in determining bactericidal capacity of J14 antisera. The reduced opsonic capacity of sera against this strain was shown to correlate with a reduced capacity to bind J14 antisera, as demonstrated by immunofluorescence microscopy and FACS analysis. In vivo challenge experiments also confirmed the protective efficacy of immunisation with J14 peptide.


Subject(s)
Antibodies, Bacterial/immunology , Glycoproteins/immunology , Opsonin Proteins/immunology , Streptococcus pyogenes/immunology , Terminal Repeat Sequences , Adolescent , Amino Acid Sequence , Animals , Antibodies, Bacterial/blood , Child , Child, Preschool , Female , Genetic Variation , Glycoproteins/genetics , Humans , Immune Sera/administration & dosage , Immunization , India/epidemiology , Mice , Mice, Inbred BALB C , Molecular Sequence Data , Streptococcal Infections/epidemiology , Streptococcal Infections/prevention & control , Streptococcal Vaccines/administration & dosage , Streptococcal Vaccines/chemistry , Streptococcus pyogenes/isolation & purification
11.
J Med Microbiol ; 54(Pt 9): 815-821, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16091431

ABSTRACT

The role of purified iron-regulated outer-membrane proteins (IROMPs) from Salmonella enterica serotype Typhi in modulation of specific T-cell responses was studied. The cellular immune response induced by IROMPs was measured by assessing the delayed-type hypersensitivity (DTH) response, lymphocyte proliferation, T-cell phenotyping and cytokine-producing cells using lymphocytes isolated from the spleen and Peyer's patches of IROMPs-immunized, immunized-challenged, infected and control mice. IROMPs immunization resulted in an enhanced DTH response and exhibited a significant increase in the protein-specific proliferative response of lymphocyte from the spleen as well as Peyer's patches. A significant increase was also observed in the ratio of CD4+/CD8+ cells in the immunized mice as compared to the infected mice. Results of the cytokine analysis revealed that during the initial period there was increased production of interleukin (IL)-2- and interferon (IFN)-gamma-producing cells in the spleen and Peyer's patches, indicating a Th1 type response, whereas in the later period of the study, increased production of IL-4-producing cells suggested a Th2 type response. The results of this study suggest a role for S. Typhi IROMPs in modulating the cellular immune response at peripheral and mucosal levels.


Subject(s)
Bacterial Outer Membrane Proteins/immunology , Iron/metabolism , Salmonella typhi/immunology , T-Lymphocytes/immunology , Animals , Bacterial Outer Membrane Proteins/administration & dosage , Cytokines , Female , Hypersensitivity, Delayed , Immunization , Immunophenotyping , Lymphocyte Activation , Mice , Mice, Inbred BALB C , Peyer's Patches/cytology , Peyer's Patches/immunology , Salmonella typhi/metabolism , Spleen/cytology , Spleen/immunology
12.
Indian J Pathol Microbiol ; 48(3): 387-9, 2005 Jul.
Article in English | MEDLINE | ID: mdl-16761764

ABSTRACT

Hairy-cell leukemia-variant (HCL-V) is a rare B-cell disorder which accountsfor 10% of HCL cases. The main features are splenomegaly, lymphocytosis and cytopenias without monocytopenia. The circulating cells have a morphology intermediate between prolymphocytes and hairy cells. The immunophenotype shows a mature B-cell phenotype with expression of B-cell antigens CD11c and CD103 but unlike typical hairy cell the cells are negative for CD25. The histology of bone marrow and spleen shows a pattern of infiltration similar to that in HCL. We present a case of HCL-V in a 66-year-old male. The bone marrow findings, immunophenotypic profile and electron microscopic features are described. The patient underwent splenectomy which also revealed infiltration by leukemia. Patients are resistant to alkylating agents and alpha-interferon (á-IFN). Splenectomy may be beneficial for long-lasting partial responses in some of the patients and is a good palliative treatment.


Subject(s)
Bone Marrow Neoplasms/pathology , Leukemia, Hairy Cell/pathology , Splenic Neoplasms/pathology , Aged , Antigens, CD/metabolism , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , B-Lymphocytes/pathology , Bone Marrow/pathology , Bone Marrow Neoplasms/immunology , CD11c Antigen/metabolism , Humans , Immunophenotyping , Integrin alpha Chains/metabolism , Leukemia, Hairy Cell/immunology , Male , Spleen/pathology , Splenic Neoplasms/immunology
13.
J Med Microbiol ; 48(1): 79-88, 1999 Jan.
Article in English | MEDLINE | ID: mdl-9920129

ABSTRACT

Porins, purified from Salmonella typhi strain 0901 provided 90% protection to BALB/c mice against a lethal dose (300 x LD50) of S. typhi Ty2 when given intraperitoneally. To measure the porin-induced cellular immune responses, macrophages and lymphocytes were isolated from spleen and lamina propria (LP) of porin immunised-challenge mice and of infected and control mice; T-cell phenotypes, lymphocyte proliferation and cytokine production were studied. The secretory IgA (sIgA) antibody level in the intestinal fluid was also measured to study mucosal immune response. After immunisation, the splenic lymphocytes exhibited a significant increase in total T-cell count and CD4+/CD8+ ratio, while the LP lymphocytes (LPL) exhibited an increase in CD4+/CD8+ ratio only. They also exhibited a significant increase in porin-specific proliferative response and cytokine levels (IL-1, IL-2, IFN-gamma and IL-4). After immunisation, sIgA antibody was also found to be increased. These results suggest that porins given intraperitoneally induce cellular and humoral immune responses both at systemic and mucosal levels.


Subject(s)
Immunization , Porins/immunology , Salmonella typhi/immunology , Typhoid Fever/immunology , Animals , Antibodies, Bacterial/biosynthesis , Immunity, Mucosal , Immunoglobulin A, Secretory/analysis , Injections, Intraperitoneal , Interferon-gamma/biosynthesis , Interleukins/biosynthesis , Intestinal Mucosa/immunology , Lymphocyte Activation , Lymphocyte Count , Macrophages/immunology , Mice , Mice, Inbred BALB C , Porins/administration & dosage , Spleen/immunology , T-Lymphocytes/immunology , Typhoid Fever/prevention & control
14.
Parasitol Int ; 52(3): 193-202, 2003 Sep.
Article in English | MEDLINE | ID: mdl-14550474

ABSTRACT

Adherence of pathogenic Entamoeba histolytica trophozoites mediated by Gal/GalNAc lectin is a prerequisite for killing naïve T cells and monocytes but the activated T cells and monocyte derived macrophages (MDMs) not only resist the attack but can kill the parasite. In the present study, we have analysed the adherence and cytotoxicity of the immunecompetent cells from patients of amoebic liver abscess at the time of their diagnosis and after 3 months to elucidate the development of cell mediated cytotoxicity, a major mechanism of resistance to amoebic infection. The results show that CD3+ cells from amoebic liver abscess cases, when stimulated, in vitro, bound E. histolytica trophozoites with increased intensity and their viability was also increased. The activated lymphocytes (taken at 3 months post treatment) were also able to kill amoebae. MDMs bound amoebae with greater intensity than lymphocytes, until 3 months post infection. These MDMs were effective in killing approximately 40% amoebae which was significantly less than at the time of diagnosis but was very significant as compared to the controls. The data suggest that cell mediated cytotoxic responses are maximum until 1 month post treatment and are significantly reduced thereafter.


Subject(s)
Entamoeba histolytica/immunology , Liver Abscess, Amebic/immunology , Monocytes/immunology , T-Lymphocytes/immunology , Adult , Animals , CD3 Complex/metabolism , Cell Adhesion , Cytotoxicity, Immunologic , Entamoeba histolytica/growth & development , Entamoeba histolytica/pathogenicity , Female , Humans , Liver Abscess, Amebic/parasitology , Lymphocyte Activation/immunology , Macrophages/immunology , Male , Middle Aged , Time Factors
15.
Indian J Pediatr ; 69(6): 471-5, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12139130

ABSTRACT

OBJECTIVE: Group A beta hemolytic streptococcus (GAS) sore throat primarily occurs among children in 5-15 years age group, and if not treated appropriately causes rheumatic fever/rheumatic heart disease (RF/RHD). Present study was aimed at validation of a clinical scoring system for diagnosis of GAS. METHODS: Five hundred and thirty six children in 5-15 years age group were enrolled by systematic random selection of households from a peri-urban slum of Chandigarh. They were visited fortnightly at their home for one year to record signs and symptoms of cough and cold. Throat swabs were collected in 918 episodes, of which 123 (13.4%) were GAS culture positive. RESULT: Significant association of GAS was found with pain in the throat, enlarged tonsils, pharyngeal erythema and tender cervical lymphadenopathy. According to the percentage positivity of GAS culture, weighted scores were assigned to age of the child, season of occurrence, fever, size of tonsil, pharyngeal erythema and exudate, lymphadenopathy and pain in throat. Combinations of various symptoms and signs gave sensitivity of 86-89% and specificity of 83-89% whereas clinical score of 15 or more had 91% sensitivity and 98% specificity for diagnosis of GAS pharyngitis. CONCLUSION: As the level of clinical acumen and prevalence of GAS may differ in different primary care settings of the country, the proposed scoring system should be validated and adapted to suit local conditions before establishing it in the primary prophylaxis strategy to prevention of RF/RHD.


Subject(s)
Pharyngitis/microbiology , Streptococcal Infections/diagnosis , Streptococcus pyogenes/isolation & purification , Acute Disease , Adolescent , Child , Child, Preschool , Female , Humans , India , Likelihood Functions , Male , Predictive Value of Tests , Sensitivity and Specificity , Urban Population
16.
Oxid Med Cell Longev ; 2013: 517045, 2013.
Article in English | MEDLINE | ID: mdl-23533693

ABSTRACT

AIMS: To examine the effect of alpha-lipoic acid, an antioxidant with mitochondrial superoxide inhibitory properties, on adrenocorticotrophic hormone- (ACTH-HT) and dexamethasone-induced hypertensions (DEX-HT) in rats and if any antihypertensive effect is mediated via mitochondrial superoxide inhibition. METHODS: In a prevention study, rats received ground food or alpha-lipoic-acid-laced food (10 mg/rat/day) for 15 nights. Saline, adrenocorticotrophic hormone (ACTH, 0.2 mg/kg/day), or dexamethasone (DEX, 10 µ g/rat/day) was injected subcutaneously from day 5 to day 11. In a reversal study, rats received alpha-lipoic-acid-laced food 4 days after commencement of saline or DEX. Tail-cuff systolic blood pressure (SBP) was measured second daily. Kidney mitochondrial superoxide was examined using (MitoSOX) Red (MitoSOX) via flow cytometry. RESULTS: SBP was increased by ACTH (P < 0.0005) and DEX (P < 0.0005). Alpha-lipoic acid alone did not alter SBP. With alpha-lipoic acid pretreatment, SBP was increased by ACTH (P' < 0.005) but not by DEX. Alpha-lipoic partially prevented ACTH-HT (P' < 0.0005) and fully prevented DEX-HT (P' < 0.0005) but failed to reverse DEX-HT. ACTH and DEX did not increase MitoSOX signal. In ACTH-hypertensive rats, high-dose alpha-lipoic acid (100 mg/rat/day) did not decrease SBP further but raised MitoSOX signal (P < 0.001), suggesting prooxidant activity. CONCLUSION: Glucocorticoid-induced hypertension in rats is prevented by alpha-lipoic acid via mechanisms other than mitochondrial superoxide reduction.


Subject(s)
Antioxidants/therapeutic use , Hypertension/prevention & control , Mitochondria/metabolism , Superoxides/metabolism , Thioctic Acid/therapeutic use , Adrenocorticotropic Hormone/toxicity , Animals , Blood Pressure/physiology , Dexamethasone/toxicity , F2-Isoprostanes/blood , Glucocorticoids/toxicity , Hypertension/chemically induced , Hypertension/metabolism , Kidney/metabolism , Male , Nitrates/blood , Nitrites/blood , Rats , Rats, Sprague-Dawley
17.
Microbes Infect ; 14(12): 1111-7, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22796386

ABSTRACT

Streptococcus pyogenes causes pharyngitis in school age children, which if left untreated causes acute rheumatic fever (ARF) that later progress toward rheumatic heart disease (RHD). The pathogenesis of this disease and its progression as post infectious squeal is not well understood. In this study, percentages of CD4(+) and CD8(+) T-cells were compared among patients of ARF, RHD and Chronic RHD using flow cytometer. The production of Th1/Th2 cytokines from serum and endothelial cells of damaged and normal heart valves was also analyzed using flow cytometer. Results showed an inverse proportion of CD4(+) and CD8(+) T-cell numbers in ARF and RHD patients. Cytokine assay demonstrated a switch-over from Th1 to Th2 type, as the disease progressed. We observed significantly high IL-6 in ARF patients and high TNF-α in early RHD patients which allowed us to construct a hypothesis, that, during initial infection phase, lot of antibodies are produced (via IL-6) and TNF-α has a role in disease progression and tissue damage during RHD phase.


Subject(s)
Disease Progression , Rheumatic Fever/immunology , Streptococcus pyogenes/immunology , Adolescent , Adult , CD4-CD8 Ratio , Child , Chronic Disease , Cytokines/metabolism , Female , Flow Cytometry , Humans , Male , Middle Aged , Th1 Cells/immunology , Th2 Cells/immunology , United States , Young Adult
18.
J Clin Immunol ; 28(5): 542-57, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18551358

ABSTRACT

INTRODUCTION: Amoebic liver abscess (ALA) is an acute inflammatory disease caused by Entamoeba histolytica. MATERIALS AND METHODS: The key player in the pathogenesis and immunoprotection is the Gal/GalNAc inhibitable lectin, possessed by both pathogenic (Entamoeba histolytica) and nonpathogenic (Entamoeba dispar) strains, but only E. histolytica infection is associated with an acute inflammation and subsequently the disease. RESULTS AND DISCUSSION: The stimulation with the lectin induces the secretion of various proinflammatory cytokines/chemokines from intestinal epithelial cells. The differential induction of cytokine/chemokine network by the two strains can further regulate the immunoregulatory functions of the immune cells (monocytes and neutrophils) of the host. The soluble levels of IL-1beta, IL-6, IL-8, IL-10, MIP-1alpha, MCP-1, RANTES, GRO-alpha, GMCSF were quantitated to be significantly higher in pathogenic lectin-induced conditioned media (LCM) compared to nonpathogenic LCM (NP-LCM). The monocytes from ALA patients responded to the presence of pathogenic-LCM (P-LCM) by lowering of intracellular Ca(2+) (which was still higher than control). The proinflammatory MCP-1, GRO-alpha, and GMCSF levels in the monocytes were recorded both (quantitatively and mRNA quantitation) to be tremendously higher along with their respective receptors, with P-LCM compared to NP-LCM. A significant increase in the reactive oxygen intermediates and chemotactic index (CI) was observed in the monocytes when treated with P-LCM. Similarly, in neutrophils of ALA patients, an increase in intracellular Ca(2+), ROS and chemotaxis was observed with P-LCM. OBJECTIVES: The study is a step towards understanding the mechanism of immunopathogenesis of amoebiasis, on one hand, and points to the central role of cytokine/chemokine network in the process, on the other hand.


Subject(s)
Asialoglycoproteins/pharmacology , Cytokines/metabolism , Entamoeba histolytica/pathogenicity , Liver Abscess, Amebic/immunology , Monocytes/metabolism , Acute Disease , Animals , Cell Line , Culture Media, Conditioned/analysis , Endocytosis , Female , Humans , Inflammation Mediators/metabolism , Intestinal Mucosa/cytology , Intestinal Mucosa/immunology , Intestinal Mucosa/metabolism , Lectins/pharmacology , Male , Monocytes/immunology , Neutrophils/immunology , Neutrophils/metabolism , Virulence/immunology
19.
J Biol Chem ; 277(10): 7766-75, 2002 Mar 08.
Article in English | MEDLINE | ID: mdl-11726649

ABSTRACT

To date, not much has been known regarding the role of CD80 and CD86 molecules in signaling of B cells. The CD28/CTLA4 ligands, CD80 (B7-1) and CD86 (B7-2), are expressed on the surface of freshly isolated splenic B cells, and their expression is up-regulated by lipopolysaccharides. In the present study, we have investigated whether signaling via CD80/CD86 could alter the proliferation and immunoglobulin synthesis of B cells. Splenic B cells were stimulated with lipopolysaccharides in the presence of anti-B7-1 (16-10A1) and anti-B7-2 (GL1) monoclonal antibodies (mAbs). Exciting features observed during the study were that cross-linking of CD86 with GL1 enhanced the proliferation and production of IgG1 and IgG2a isotypes. In contrast, anti-B7-1 (16-10A1) mAb could efficiently block the proliferation and production of IgG1 and IgG2a. Furthermore, GL1 mAb could also induce the secretion of IgG isotypes from B cell lymphomas. Importantly, 16-10A1 could retard the growth of lymphomas and favored the up-regulation of pro-apoptotic molecules caspase-3, caspase-8, Fas, FasL, Bak, and Bax and down-regulation of anti-apoptotic molecule Bcl-x(L). In contrast, GL1 augmented the level of anti-apoptotic molecules Bcl-w and Bcl-x(L) and decreased the levels of pro-apoptotic molecule caspase-8, thereby providing a novel insight into the mechanism whereby triggering through CD80 and CD86 could deliver regulatory signals. Thus, this study is the first demonstration of a distinct signaling event induced by CD80 and CD86 molecules in B cell lymphoma. Finally, the significance of the finding is that CD80 provided negative signal for the proliferation and IgG secretion of normal B cells and B cell lymphomas. In contrast, CD86 encouraged the activity of B cells.


Subject(s)
Antigens, CD/physiology , B-Lymphocytes/metabolism , B7-1 Antigen/physiology , Lymphoma, B-Cell/metabolism , Membrane Glycoproteins/physiology , Animals , Antibodies, Monoclonal/metabolism , Apoptosis , B7-2 Antigen , Caspase 3 , Caspase 8 , Caspase 9 , Caspases/metabolism , Cell Division , Cell Line , Cell Separation , Cross-Linking Reagents/pharmacology , Dose-Response Relationship, Drug , Dose-Response Relationship, Immunologic , Down-Regulation , Fas Ligand Protein , Female , Flow Cytometry , Humans , Immunoglobulin G/metabolism , Ligands , Lipopolysaccharides/metabolism , Lymphoma/metabolism , Membrane Glycoproteins/metabolism , Membrane Proteins/metabolism , Mice , Mice, Inbred BALB C , Protein Binding , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Signal Transduction , Time Factors , Tumor Cells, Cultured , Up-Regulation , bcl-2 Homologous Antagonist-Killer Protein , bcl-2-Associated X Protein , bcl-X Protein , fas Receptor/metabolism
20.
Anal Quant Cytol Histol ; 26(5): 271-7, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15560533

ABSTRACT

OBJECTIVE: To perform a quantitative analysis of DNA ploidy, S-phase fraction % (SPF%), p53 and multidrug resistance (MDR) gene expression as independent prognostic parameters and to compare these parameters with stage of the disease in multiple myeloma (MM) patients. STUDY DESIGN: Peripheral blood bone marrow samples were analyzed for DNA ploidy and SPF% using a FACScan flow cytometer (Becton Dickinson). Detection of p53 and MDR gene expression was done using immunocytochemistry. RESULTS: Aneuploidy was found in 5/48 (10.42%) total myeloma patients, all of whom revealed hyperdiploidy. High SPF% was noted in 18/37 (48.65%) newly diagnosed MM patients and 5/11 (45.45%) follow-up cases of myeloma. p53 Gene product was noted in 8/48 (16.66%) myeloma patients, 6 newly diagnosed and 2 on follow-up. MDR gene expression was detected in 4/27 (10.81%) newly diagnosed patients and in 1/11 (9.09%)follow-up patients. CONCLUSION: All myeloma patients with aneuploidy revealed hyperdiploidy. The majority of cases with high SPF% were at advanced stages, indicating the prognostic significance of SPF%. Although, there was no statistical significance of DNA ploidy, SPF%, p53 and MDR gene product expression, they are important prognostic parameters. Our results can provide baseline data for comparison with future studies since these parameters have not been reported earlier from the Indian subcontinent.


Subject(s)
ATP Binding Cassette Transporter, Subfamily B/analysis , Multiple Myeloma/pathology , Ploidies , Tumor Suppressor Protein p53/analysis , Adolescent , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Biomarkers/analysis , DNA/analysis , Female , Flow Cytometry , Humans , Male , Middle Aged , Multiple Myeloma/diagnosis , Prognosis , S Phase
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