Kalpana Luthra - Academia.edu (original) (raw)

Papers by Kalpana Luthra

The neutralization breadth of plasma antibodies from 2 samples of HIV-1 infected ART-nai... more The neutralization breadth of plasma antibodies from 2 samples of HIV-1 infected ART-naive individuals from India were assessed against a panel of 13 subtype B and C viruses. Plasma neutralization is shown as the reciprocal value of the ID50, which is the plasma dilution at which virus infectivity is inhibited to 50%. Data presentation is as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0125575#pone.0125575.t001" target="_blank">Table 1</a>. Each experiment was performed at least twice, independently.Cross-neutralization activity of two plasma samples from HIV-1 infected Indian individuals against a panel of 13 pseudoviruses (1 subtype A, 6 subtypes B and 6 subtype C viruses).</p

The depletion and competition of antibodies from three cross-neutralizing plasma (CNP) (... more The depletion and competition of antibodies from three cross-neutralizing plasma (CNP) (AIIMS206, AIIMS239 and AIIMS249) was carried out with V3 (35 mer), MPER (25 mer) and IDR (19 mer) specific peptides. The antibodies from CNP were depleted by passing plasma samples (at 1∶30 dilution) over antigen coated ELISA plates (peptide coating concentration, 10 µg/ml) six times and the percent depletion of antibodies to each region was calculated as: percent depletion = 100−[100×(OD405 at the last passage/OD405 at the first passage)]. The percentage antibody depletion for CNP against each peptide is shown (A). As control, mock depletion of CNP was carried out on the uncoated plates which showed minimal effect on antibody depletion (A). For competition, CNP were preincubated 30 minutes with the same peptides at a final peptide concentration of 20 µg/ml. Both depleted (designated as ‘D’) and competed (designated as ‘+’) plasma were subsequently tested for neutralization with all eight viruses (data shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043704#pone-0043704-t003" target="_blank">Table 3</a>). To validate the competition assay, we tested 447-52D an anti-V3 antibody known to neutralize SF162 (a tier 1 sensitive subtype-B virus) along with two peptides corresponding to consensus-C and B V3 sequences (at a final concentration, 10 µg/ml) (B).</p

HIV-1 superinfection is defined as infection by an unrelated second strain of HIV-1 after serocon... more HIV-1 superinfection is defined as infection by an unrelated second strain of HIV-1 after seroconversion due to primary infecting strain and has been associated with development of breadth in the neutralizing antibody (nAb) response, altered disease progression and efficacy of antiretrovirals; though conflicting observations have also been reported. Superinfection has been reported in HIV-1 infected adults. Recently we observed that multivariant infection in infants was associated with early induction of plasma broadly neutralizing antibodies (bnAbs) targeting diverse autologous viruses, however, there is paucity of information on infants with HIV-1 superinfection. Furthermore, the mechanisms by which superinfection in an infant, after priming by an initial infection, potentiate the evolution of a bnAb response have not been evaluated. Herein, we performed a longitudinal analysis and observed evolution of nAb responses in an antiretroviral naïve perinatally HIV-1 infected infant, wi...

The trimeric envelope glycoprotein (gp120/gp41) 3 of human immunodeficiency virus-1 (HIV-1) media... more The trimeric envelope glycoprotein (gp120/gp41) 3 of human immunodeficiency virus-1 (HIV-1) mediates viral and host cell membrane fusion, initiated by binding of viral envelope gp120 protein to the CD4 receptor on host immune cells. Functional env genes from infected individuals have been widely used as templates for vaccine design, for setting up viral neutralization assays and to study the 1 viral evolution and pathogenesis. Traditional topoisomerase or T4 DNA polymerase mediated 1 approaches for cloning single genome amplified (SGA) env genes are labor-intensive, cost-ineffective 1 with low-throughput, thereby enabling functional analysis of only a limited number of env genes from 1 the diverse circulating quasispecies in infected individuals. Herein, we report an efficient, easy to 1 optimize and high-throughput approach for cloning diverse HIV-1 env genes. Multiple env/rev gene 1 cassettes, derived from infected infants, were subjected to SGA using Phusion polymerase and 1 utilized as megaprimers in overlap extension PCR mediated cloning (OEC), circumventing the 1 requirement for novel enzymes. Furthermore, utilization of Phusion polymerase for both the 1 amplification of env/rev cassettes and OEC allows convenient monitoring and optimization, thereby 1 providing much greater flexibility and versatility for analysis of env genes from HIV-1 infected 2 individuals.

Journal of Virology, 2019

Broad and potent neutralizing antibodies (bnAbs) with multiple epitope specificities evolve in HI... more Broad and potent neutralizing antibodies (bnAbs) with multiple epitope specificities evolve in HIV-1-infected children. Herein, we studied two antiretroviral-naive chronically HIV-1 clade C-infected monozygotic pediatric twins, AIIMS_329 and AIIMS_330, with potent plasma bnAbs. Elite plasma neutralizing activity was observed since the initial sampling at 78 months of age in AIIMS_330 and persisted throughout, while in AIIMS_329 it was seen at 90 months of age, after which the potency decreased over time. We evaluated potential viral characteristics associated with the varied immune profiles by generating single genome-amplified pseudoviruses. The AIIMS_329 viruses generated from the 90-month time point were neutralization sensitive to bnAbs and contemporaneous plasma antibodies, while viruses from the 112-month and 117-month time points were resistant to most bnAbs and contemporaneous plasma. AIIMS_329 viruses developed resistance to plasma neutralizing antibodies (nAbs) plausibly b...

Journal of the Anatomical Society of India, 2018

Introduction: Preeclampsia (PE) and its subtypes (early and late onset) are serious concerns all ... more Introduction: Preeclampsia (PE) and its subtypes (early and late onset) are serious concerns all across the globe affecting about 8% of overall pregnancies and accounts for approximately 60,000 deaths annually with a predominance in developing countries. The two-stage model, deficient spiral artery remodelling (stage I) and an imbalance between angiogenic and anti-angiogenic factor(s) (stage II) are well established facts so far. Increased sFlt-1 along with high oxidative stress and endoplasmic reticulum stress (ER stress) have recently been suggested in pregnancies with PE. The second decade of 21st century highlighted a new window to explore further the role of endoplasmic reticulum stress in the onset of the variant forms of PE. In our previous studies, we reported apoptosis and oxidative stress, induced by sFlt-1 in trophoblast cells. However, the role of sFlt-1 in inducing ER stress is still an unrevealed hugger-mugger till date. Methods: Study was divided into two parts (1) Serum Analysis of sFlt-1 and GRP78 was done using ELISA (2) In Vitro experiments: Activation of ER stress markers (GRP78, eIF2α and CHOP) were assessed at various time points (8 h, 14 h, 24 h) at protein (Immunofluorescence, Western blot) and transcript level (qRT-PCR). Results: Significant raised levels of sFlt-1 and GRP78 in preeclamptic sera was found. We observed significant ER stress in the placental cells (BeWo Cells) (in vitro) when exposed to normotensive sera with recombinant sFlt-1 and also when treated with recombinant sFlt-1 alone. Discussion: We reported significant ER stress in the placental cells (BeWo Cells) (in vitro) when exposed to normotensive sera with recombinant sFlt-1 and also when treated with recombinant sFlt-1 alone.

Dementia and Geriatric Cognitive Disorders, 2010

Access to full text and tables of contents, including tentative ones for forthcoming issues: www.... more Access to full text and tables of contents, including tentative ones for forthcoming issues: www.karger.com/dem_issues 121 An MRI-Based Semiquantitative Index for the Evaluation of Brain Atrophy and Lesions in Alzheimer's Disease, Mild Cognitive Impairment and Normal Aging

Viruses, Jan 10, 2015

The success of highly active antiretroviral therapy (HAART) is challenged by the emergence of res... more The success of highly active antiretroviral therapy (HAART) is challenged by the emergence of resistance-associated mutations in human immunodeficiency virus-1 (HIV-1). In this study, resistance associated mutations in the reverse transcriptase (RT) and protease (PR) genes in antiretroviral therapy (ART) naïve and treated HIV-1 infected pediatric patients from North India were evaluated. Genotyping was successfully performed in 46 patients (30 ART naive and 16 treated) for the RT gene and in 53 patients (27 ART naive and 26 treated) for PR gene and mutations were identified using Stanford HIV Drug Resistance Database. A major drug resistant mutation in RT gene, L74I (NRTI), and two such mutations, K101E and G190A (NNRTI), were observed in two ART naïve patients, while M184V was detected in two ART treated patients. Overall, major resistance associated mutations in RT gene were observed in nine (30%) and seven (36%) of ART naïve and treated children respectively. Minor mutations wer...

AIDS Research and Human Retroviruses, 2014

Journal of Clinical Immunology, 2014

Little is known about the neutralizing antibodies induced in HIV-1 patients on antiretroviral tre... more Little is known about the neutralizing antibodies induced in HIV-1 patients on antiretroviral treatment, which constitute an interesting group of individuals with improved B cell profile. Plasma samples from 34 HIV-1 seropositive antiretroviral drug treated (ART) patients were tested for neutralization against a panel of 14 subtype-A, B and C tier 1 and tier 2 viruses in TZM-bl assay. Of the 34 plasma samples, remarkably all the plasma samples were able to neutralize at least one virus while 32 (94 %) were found to neutralize ≥50 % viruses tested. In terms of overall neutralization frequency, approximately 86 %, 68 % and 17 % of the virus/plasma combinations showed 50 % neutralizing activity at 1>60, 1≥200 and 1≥ 2000 dilutions respectively. The improvement in neutralizing activity was shown to be associated with ART in two follow up patients. The neutralization of viruses by two representative plasma samples, AIIMS221 and AIIMS265, was exclusively mediated by immunoglobulin G fractions independent of ART drugs and IgG retained cross-reactive binding to recombinant gp120 proteins. We observed a positive trend of neutralization with duration of ART (p=0.06), however no such correlation was found with clinical and immunological variables like CD4 count (p=0.35), viral load (p=0.09) and plasma total IgG (p= 0.46). Our study suggests that the plasma antibodies from ART patients display high neutralizing activity most likely due to an improved B cell function induced by ART despite low antigenic stimulation.

Archives of Virology, 2012

In this cross-sectional study, we evaluated the efficiency of the plasma of 38 antiretroviral-naï... more In this cross-sectional study, we evaluated the efficiency of the plasma of 38 antiretroviral-naïve HIV-1-infected children from northern India against a standard panel of pseudoviruses (3 clade C and 3 clade B) by TZM-bl assay. Neutralization potential was observed to a variable extent, with a potency ranging up to reciprocal ID(50) titers of 1967. Cross-neutralization was observed in 28.9 % (11/38) of the children. There was a significant positive correlation between viremia and neutralization efficiency against two of the viruses studied (Du172 r = 0.49; p = 0.007 and RHPA r = 0.47; p = 0.01), suggesting that persistent antigenic stimulation is necessary for the generation of broadly neutralizing antibody responses in these children. Further mapping of the epitope specificities of the neutralization determinants in the polyclonal plasma would provide important information for immunogen design.

Alimentary Pharmacology & Therapeutics, 2011

BACKGROUND-Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver dis... more BACKGROUND-Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in children. Liver disease can be a cause of low bone mineral density. Whether NAFLD influences bone health is unknown. AIM-To evaluate bone mineral density in obese children with and without NAFLD. METHODS-Thirty-eight children with biopsy-proven NAFLD were matched for age, sex, race, ethnicity, height, and weight to children without evidence of liver disease from the National Health and Nutrition Examination Survey. Bone mineral density was measured by dual energy xray absorptiometry. Age and sex-specific bone mineral density Z-scores were calculated and compared between children with and without NAFLD. After controlling for age, sex, race, ethnicity, and total percent body fat, the relationship between bone mineral density and the severity of histology was analyzed in children with NAFLD. RESULTS-Obese children with NAFLD had significantly (p<0.0001) lower bone mineral density Z-scores (−1.98) than obese children without NAFLD (0.48). Forty-five percent of children with NAFLD had low bone mineral density for age, compared to none of the children

Metabolic Syndrome and Related Disorders, 2016

Objective: The aim of this study was to compare the discriminatory ability of body mass index (BM... more Objective: The aim of this study was to compare the discriminatory ability of body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) in identifying the presence of cardiometabolic risk factors in Asian Indians. Methods: This cross-sectional study involved 509 subjects (278 males and 231 females) aged 20-60 years from New Delhi, India. Measurements included complete clinical examination, blood pressure, weight, height, WC, BMI, WHR and WHtR, fasting blood glucose, lipid profile, and fasting insulin levels. Receiver operating characteristic curve analyses were performed to compare predictive validity of various adiposity measures against the cardiometabolic risk factors (dyslipidemia, hyperinsulinemia, impaired fasting glucose, hypertension, and metabolic syndrome). The odds ratio for the presence of individual cardiometabolic risk factors in the presence of overweight, abdominal obesity, and high WHtR were calculated using logistic regression analysis. Results: WC had the highest area under ROC for all other cardiometabolic risk factors except hyperinsulinemia in males and for dyslipidemia, metabolic syndrome and presence of at least one cardiometabolic risk factor in females. For metabolic syndrome, WC, followed by WHtR, was observed to be the better predictor than other measures of adiposity, and WHtR appeared to be the best predictor for hypertension in both genders, particularly in women. Conclusions: In the northern Asian Indian population with high prevalence of cardiometabolic risk factors, a combination of WC and WHtR appeared to be having better clinical utility than BMI and WHR in identifying individuals with cardiometabolic risk factors.

The Journal of the Association of Physicians of India, 2008

To evaluate the levels and appropriate cutoff points of fasting insulin, and their association wi... more To evaluate the levels and appropriate cutoff points of fasting insulin, and their association with the metabolic syndrome (MS) in Asian Indian adolescents. This cross-sectional, population based study included 948 (527 males & 421 females) adolescent subjects aged 14-19 years selected randomly from New Delhi, India. Cutoff points of fasting insulin were defined using Receiver Operating Characteristics curve analysis against overweight, abdominal obesity and high subscapular skinfold thickness. The MS was defined according to NCEP, ATP III and IDF criteria using age-, gender- and ethnicity-specific cutoff points. Fasting insulin levels peaked at 16 y and reduced subsequently in both genders. The derived cutoff points for fasting insulin (pmol/L) were: 14-15 y- 128.5 and 164.8; 16-17 y- 126.1 and 152.8; 18-19 y- 121.2 and 162.4 in males and females, respectively. Prevalence of fasting hyperinsulinemia (39.1%) and MS (NCEP 2.2%, IDF 1.5%) was highest in age group 16-17 years. The data...

PLoS ONE, 2014

Background: Enlargement of adipocyte is associated with their dysfunction and alterations in meta... more Background: Enlargement of adipocyte is associated with their dysfunction and alterations in metabolic functions. Objectives: We evaluated the association of adipocyte size of subcutaneous and omental adipose tissue with body composition and cardiovascular risk factors in Asian Indians. Methodology: Eighty (40 males and 40 females) non-diabetic adult subjects undergoing elective abdominal surgery were included. Pre-surgery evaluation included anthropometric measurements, % body fat by bioimpedance, abdominal fat area at L 2-3 level (computed tomography) and biochemical investigations (fasting blood glucose and insulin, lipids and hsCRP). During surgery, about 5 grams each of omental and subcutaneous adipose tissue was obtained for adipocyte size determination. Results: Females had higher BMI, % body fat, skinfold thickness, total and subcutaneous abdominal fat area as compared to males. Overweight was present in 42.5% and 67.5%, and abdominal obesity in 5% and 52.5% males and females, respectively. Subcutaneous adipocyte size was significantly higher than omental adipocyte size. Omental adipocyte size correlated more strongly than subcutaneous adipocyte size with measures of adiposity (BMI, waist circumference, %BF), total and subcutaneous abdominal fat area and biochemical measures (fasting glucose, total cholesterol, triglycerides and HOMA-IR), the correlations being stronger in females. The correlation of adipocyte size with metabolic parameters was attenuated after adjusting for measures of adiposity. Conclusion: Omental adipocyte size, though smaller than the subcutaneous adipocyte size, was more closely related to measures of adiposity and metabolic parameters. However, the relationship was not independent of measures of adiposity.

Disease Markers, 2011

Objectives:Obesity is associated with high levels proinflammatory cytokines like tumour necrosis ... more Objectives:Obesity is associated with high levels proinflammatory cytokines like tumour necrosis factor alpha (TNF-α), which may play an important role in the genesis of insulin resistance. We evaluated the relationship of −308G/Apolymorphism ofTNF-αgene with obesity and insulin resistance in Asian Indians in north India.Methods:This cross-sectional study included 151 apparently healthy individuals (79 males, 72 females) 18–50 yrs of age from New Delhi, India. Body composition by dual-energy x-ray absorptiometry (DEXA) and abdominal fat by magnetic resonance imaging (MRI) were measured. Biochemical measurements included OGTT, lipids, fasting insulin, hs-CRP and TNF-αlevels. We analysed −308G/Apolymorphism ofTNF-αgene and studied its association with obesity and biochemical parameters.Results:At comparable BMI, abdominal obesity was more prevalent in females (50%) as compared to males (20%). The wild genotype (GG) was present in 78.8%, GA in 17.9%, andAAin 3.3% subjects. Measures of ...

Disease Markers, 2006

Purpose:To investigate the relationship of apolipoprotein E (apoE) genotype, plasma levels of apo... more Purpose:To investigate the relationship of apolipoprotein E (apoE) genotype, plasma levels of apoE and lipids in temporal lobe epilepsy (TLE) patients in Asian Indians. Status of plasma levels of Apo E in epilepsy patients has not been reported till date.Methods:ApoE gene polymorphism was analyzed in 58 patients with temporal lobe epilepsy (TLE) and 57 age and sex approximated controls using Polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP). Levels of plasma apoE and lipids were measured using ELISA and enzymatic kits respectively.Results:The distribution of ApoE genotype in epilepsy patients and controls was comparable. Higher levels of plasma ApoE were observed in TLE patients as compared to controls (p= 0.0001). Individuals with plasma levels of apoE > 190 mg/L were at 20 times higher odds (95%CI = 2.46–163.34,p= 0.005), while those with levels of apoE between 150–190 mg/L were at 4.9 times higher odds (95% CI = 1.85–13.9,p= 0.001), to develop TLE....

Dementia and Geriatric Cognitive Disorders, 2010

Background: Remarkable improvement in the life expectancy of the Indian population is expected to... more Background: Remarkable improvement in the life expectancy of the Indian population is expected to commensurate with the increase in number of dementia cases. Among various types of dementia, Alzheimer’s disease (AD) and vascular dementia (VaD) are common and widely studied. We evaluated the role of apolipoprotein E (ApoE) and interleukin-6 (IL-6)–174 G/C gene polymorphism along with serum IL-6 levels in AD and VaD patients. Methods: The polymorphisms in ApoE and IL-6–174 G/C genes were assessed using RFLP. Serum IL-6 level was measured by ELISA. Results: The allele Ε4 of the ApoE gene was found to be associated with AD and VaD patients (p < 0.05). No association of IL-6–174 G/C polymorphism was observed in AD patients, while the IL-6–174 C allele increased the odds of having VaD twofold. Regression analysis to assess possible interaction between ApoE and the IL-6–174 G/C genes revealed that presence of both the Ε4 and C alleles increased the odds of having AD 13.75-fold and VaD 1...

Journal of Virology, 2019

Journal of the Anatomical Society of India, 2018

Dementia and Geriatric Cognitive Disorders, 2010

Viruses, Jan 10, 2015

AIDS Research and Human Retroviruses, 2014

Journal of Clinical Immunology, 2014

Archives of Virology, 2012

Alimentary Pharmacology & Therapeutics, 2011

Metabolic Syndrome and Related Disorders, 2016

The Journal of the Association of Physicians of India, 2008

PLoS ONE, 2014

Disease Markers, 2011

Disease Markers, 2006

Dementia and Geriatric Cognitive Disorders, 2010