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Cellular Immune Responses in Typhoid Fever Patients and Vaccinees

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT03600025
Recruitment Status : Recruiting
First Posted : July 26, 2018
Last Update Posted : February 18, 2021
University of Oxford
Information provided by (Responsible Party):
International Centre for Diarrhoeal Disease Research, Bangladesh

Tracking Information
First Submitted Date  ICMJE July 12, 2018
First Posted Date  ICMJE July 26, 2018
Last Update Posted Date February 18, 2021
Actual Study Start Date  ICMJE July 15, 2018
Estimated Primary Completion Date September 30, 2021   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: July 24, 2018)
  • MAIT cells and NK cells in the typhoid vaccine recipients [ Time Frame: up to 30 days ]
  • Roles of IL-21, IL-12. IL-15 and IL-18 in the activation of natural killer cells and generation of memory like NK cells in typhoid fever and vaccinees [ Time Frame: up to 30 days ]
  • In vitro capacity of NETs to trap and kill S. Typhi [ Time Frame: up to 30 days ]
Original Primary Outcome Measures  ICMJE Same as current
Change History
Current Secondary Outcome Measures  ICMJE Not Provided
Original Secondary Outcome Measures  ICMJE Not Provided
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
Descriptive Information
Brief Title  ICMJE Cellular Immune Responses in Typhoid Fever Patients and Vaccinees
Official Title  ICMJE Investigation of Innate Immune Responses to Salmonella Typhi in Typhoid Fever in Children and Adults Patients and Vaccinees in Dhaka, Bangladesh
Brief Summary Typhoid fever caused by Salmonella Typhi and Paratyphi causes over 21 million cases of febrile illness and 200,000 deaths are attributed to enteric fever each year. Typhoid fever is an enteric infection that results in febrile illness. Typhoid fever causes significant morbidity in the developing world especially young children.S. Typhi specific antibody responses are elicited in typhoid fever and following typhoid vaccination. Cross-reactive multifunctional CD+4 T cell mediated IL-17 responses have been shown in typhoid fever. As S. Typhi as an intracellular pathogen, cellular immune responses might be central to protection. S. Typhi peptide subunit vaccine elicits CD+4 T cell responses that correlate with protection in mice. The role of mucosal associated invariant T cell (MAIT) and natural killer (NK) cell responses in typhoid fever or following vaccination remain poorly understood. Transcriptome profiling of human immune responses to S. Typhi infection is not clearly understood. Establishing successful infection by S. Typhi evasion of T cell and neutrophil responses need to be investigated to better understand the correlates of protection.
Detailed Description

Description of the Research Project: It has been previously shown that IFN-gamma and IL-17 are increased in typhoid fever patients. It was shown that S. Typhi infection induces antibody responses against a number of key typhoid antigens (LPS) HlyE, Flagellar protein FliC and chaperon protein EcpD). In the enteric diarrheal disease cholera, MAIT cells are activated and associated LPS specific antibody responses are generated. In a human challenge model study, it has been shown that CD8+ T cell memory cells are key correlates of protection against typhoid fever. The live attenuated typhoid vaccine (TY21a) also induces MAIT cells after immunization. It has been shown that IL-12, IL-15, IL-18 induce memory-like NK cells in a mouse model and IL-21 induces memory-like NK cells protective against Mycobacterium tuberculosis infection. The role of activated MAIT cells, and cytokine induced memory-like NK cells in typhoid fever currently unknown.

One of the multiple killing mechanism employed by neutrophil is the release of neutrophil extracellular traps (NETs) that contain myeloperoxidase (MPO), elastase, lysozyme and defensins. Infection induces releases of NETs to trap microbial pathogens. Neutrophils isolated from typhoid fever patients release NETs in and that neutrophil NET release is primed by vaccination with a subunit-conjugate vaccine.

Study intervention: Typbar-TCV is a Typhoid Vi capsular polysaccharide tetanus toxoid conjugate vaccine. Typbar-TCV is the world's 1st clinically proven conjugate typhoid vaccine. This vaccine is WHO pre-qualified and approved for children and infants less that 2 years of age. During the Phase III clinical study, a single dose of Typbar-TCV elicited 4-fold seroconversion rates of 98.05%, 99.17% and 92.13% in subjects between greater than 6 months to 2 years, >2 to 15 years and >15 to 45 years respectively. Each volunteer in the vaccination arm of the study will receive 25 ug of Typbar-TCV vaccine administered as 0.5 ml single intracellular dose.

Storage condition: The vaccine will be stored at +2-8C and cold chain will be maintained at all times.

Study participants and sample collection: The investigators will collect 8-10 ml of blood from adults and 3-5 ml of blood from children who will be suspected typhoid fever patients (age 1-59 years) at enrollment (day1) and if patient is S. Typhi/Paratyphi culture confirmed then two more blood samples (2-5 days and 27-33 days later) will be collected. The investigators will collect 8-10 ml of blood from adults and 3-5 ml of blood from children before vaccination (day 0) and two more blood samples after one dose of vaccination at day 7 (6-8 days later) [13] and at day 30 (27-33 days later). Peripheral blood mononuclear cells (PBMCs) and neutrophils will be isolated from blood samples and will be used for different assays (Polymorphprep kit). Plasma samples will be separated to measure antibody response to infection and vaccination.

Patient management Depending on discretion of clinician, treatment of the patient with antibiotic and other necessary drug will be provided. After culture confirmation of typhoid fever antibiotic treatment will be adjusted depending on antibiotic sensitivity pattern. If patient does not respond to oral antibiotic then we will provide injectable antibiotic. If the patient remains unresponded to injectable antibiotic and/or other complication arise, then the patient will be hospitalized. The investigators are conducting another typhoid study where the patients are enrolled in different health care facilities in Mirpur and also icddr,b Dhaka hospital. The patient management will be supported by other ongoing typhoid project.

Laboratory Assay Procedure:

MAIT and NK cell assay: Isolated PBMCs will be stained with fluorochrome labelled antibodies and flow cytometric phenotyping performed (acquisition of ≥50000 live cells on a FACS-Aria). MAIT cells will be defined as live (DAPI-) CD3+CD4-CD161hiVα7.2+ cells, expressed as a percentage of total CD3+ lymphocytes, and CD38 used as a marker of cell activation. The investigators will also assess the frequency of circulating live CD3+CD8+CD4-CD161loVα7.2+ cells, which have been suggested to be MAIT-derived cells associated with absent or reduced cytokine secretion in vitro. CD4+ (live CD3+ CD8-CD4+) T cell responses in study subjects will be evaluated in different T memory (TM) subsets defined by their expression of CD45RA and CD62L i.e., T central memory (TCM; CD45RA-CD62L+), T effector memory (TEM; CD45RA-CD62L-) and T effector memory CD45RA+ (TEMRA; CD45RA+CD62L-), T follicular (CD3+CXCR5+) and Naïve T cells (TN: CD45RA+CD62L+). Activated NK cell as live CD3-, CD45+, CD56+, CD69+, CD40L+, CD16+ cells and memory like NK cell as live CD3-CD56+CD16+NKp46+CD27+.

Cytokine analysis: Isolated lymphocytes will be stimulated with S. Typhi antigens (Whole cell, MP and LPS) for 48 hours as well as for 5 days and culture supernatant will be collected and stored until analyzed at -70°C. Cytokines in culture supernatant will be analyzed by using multiplex bead array (Luminex).

Quantitation of NETs: Neutrophils will be isolated from peripheral blood based on previously described method. The release of NETs will be measured by neutrophil NET assay kit (NET assay kit, Creative Biomart, NY, USA). NETosis will be quantified by measuring levels of elastase that are released from neutrophils and NETs mediated killing will be quantified by measuring viability of bacteria.

NETs mediated killing assay: To determine the efficiency of NETs in killing S. Typhi, a CFU assay will be performed. Overnight culture S. Typhi will be co-incubated with freshly isolated human neutrophils in 96-well culture plate and incubated at 37ºC. After 3 hours of incubation, wells will be aspirated and washed with PBS. Dilutions of 1:10 and 1:100 will be made and 100 µl of each dilution will be plated onto Brain Heart Infusion (BHI) agar. Culture plates will be incubated at 37ºC with 5% CO2. The number of CFU will be counted after 24 hours incubation and after 3 days of culturing until no further increase in colony numbers are observed.

Neutrophil intracellular metabolite assay: Neutrophils will be isolated from blood and incubated at 37ºC for 1 hour for recovery. Incubation media will be aspirated and 1 ml of dry ice (-80ºC) cold 80% methanol will be added. Cells will be vortexed for 1 min, and then centrifuged at 15 K rpm for 1 min. Supernatant will be collected in tubes and stored at -80ºC until use. Before analysis samples will be removed from -80ºC and allow to equilibrate to room temperature. Supernatant (75 µl) will be transferred to a liquid chromatography-tandem mass spectrometry (LC-MS) vial capped. Ten microliters of sample will be autoloaded into LC-MS system for metabolite separation and mass spectrometric analysis.

Antibody responses to lipopolysaccharide (LPS) in plasma. Plasma antibody responses to S. Typhi LPS in patients and vaccinees will be measured using ELISA methods. Briefly, 96-well microtiter plates will be coated with LPS and incubated with plasma (1:10 dilution) with serial 3-fold dilutions thereafter. Plates will be washed, and horseradish peroxidase-conjugated anti-human IgA, IgG and IgM antibodies will be added. Plates will be developed using 0.1% ortho-phenylene diamine (OPD) and 0.1% hydrogen peroxide (H2O2), and OD will be measured at 492 nm. A 2-fold or higher antibody response will be considered a significant response.

Transcriptomics analysis: From a subset of adult patients and vaccinees 3 ml blood will be collected in Tempus RNA tubes (applied biosystem) and RNA will be extracted from blood, trancriptomic sequencing will be done at Shanghi, China (BGI) which is a service providing lab and data will be analyzed using next-gen RNA-seq sequencing to see the gene expression profile. Differential gene expression will be analysed using the DESeq package (Bioconductor). The obtained sequence reads will be normalized between patients/vaccinees versus healthy controls. A ratio larger than 2 and lower that 0.5 will be considered significant.

Study Type  ICMJE Interventional
Study Phase  ICMJE Phase 1
Study Design  ICMJE Allocation: N/A
Intervention Model: Single Group Assignment
Intervention Model Description:
Apparently healthy volunteers will receive typhoid vaccine one time point.
Masking: None (Open Label)
Primary Purpose: Basic Science
Condition  ICMJE Typhoid Fever Patients and Healthy Volunteers to Receive Typbar-TCV Vaccine
Intervention  ICMJE Biological: Typbar-TCV vaccine
vaccine will receive intramuscularly
Study Arms  ICMJE non-randomized
Responses will be compared before and after vaccination
Intervention: Biological: Typbar-TCV vaccine
Publications * Not Provided

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status  ICMJE Recruiting
Estimated Enrollment  ICMJE
 (submitted: July 24, 2018)
Original Estimated Enrollment  ICMJE Same as current
Estimated Study Completion Date  ICMJE December 30, 2021
Estimated Primary Completion Date September 30, 2021   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

Inclusion Criteria:

  • Inclusion criteria 1. Apparently healthy

Exclusion Criteria:

  • 1. Previously history of illness in the last one month. 2. History of taking typhoid vaccine and history of typhoid fever. 3. History of taking any other live or killed enteric vaccine in the last 4 weeks.
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 1 Year to 59 Years   (Child, Adult)
Accepts Healthy Volunteers  ICMJE Yes
Contacts  ICMJE
Contact: Md Saruar Bhuiyan, PhD 88029827001-10 ext 2422
Contact: Farhana Khanam, M.Phil 88029827001-10 ext 2433
Listed Location Countries  ICMJE Bangladesh
Removed Location Countries  
Administrative Information
NCT Number  ICMJE NCT03600025
Other Study ID Numbers  ICMJE PR-17082
Has Data Monitoring Committee Yes
U.S. FDA-regulated Product
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
IPD Sharing Statement  ICMJE
Plan to Share IPD: No
Current Responsible Party International Centre for Diarrhoeal Disease Research, Bangladesh
Original Responsible Party Same as current
Current Study Sponsor  ICMJE International Centre for Diarrhoeal Disease Research, Bangladesh
Original Study Sponsor  ICMJE Same as current
Collaborators  ICMJE University of Oxford
Investigators  ICMJE Not Provided
PRS Account International Centre for Diarrhoeal Disease Research, Bangladesh
Verification Date July 2020

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP