Background: Knowledge of antigen-specific CD4+ T cells frequencies is pivotal to the choice of the antigen to be used in anti-viral and anti-tumor vaccination procedures and for monitoring of immune responses. Methods that employ small cell numbers from patient samples, are easy to perform and do not require complex techniques/instrumentations and therefore standardization are desirable. Methodology/Principal Findings: Purified blood CD4+ T cells from healthy donors were cultured with autologous antigen presenting cells in several replicate wells in equal numbers in the absence (un-stimulated wells) or in the presence of synthetic peptides corresponding to viral antigens promiscuous HLA-DR epitopes (antigen-stimulated wells). At day 7 of culture low dose IL-2 was added and at day 14 IFN-c and IL-5 release in the supernatant was measured. A statistical analysis approach, based on Poisson distribution, was then implemented to calculate the frequency of viral-specific CD4+ T cells. We first determined a patient-specific exceptionality threshold of cytokine release in the un-stimulated wells and then, based on this threshold, we counted the inactive/active wells within the antigen-stimulated wells. This number, along with the number of cells per well, allowed the point and interval estimates of frequencies. A ready-to-use Excel worksheet template with automatic calculations for frequencies estimate was developed and is provided as a supplemental file (Table S9). Conclusions/Significance: We report a simple experimental procedure combining short term in vitro cell culture with statistical analysis to calculate the frequency of antigen-specific CD4+ T cells. The detailed experimental procedure along with the Excel applicative are a valuable tool for monitoring immune responses in the clinical practice.

Estimating point and interval frequency of antigen-specific CD4+ T cells based on short in vitro expansion and improved poisson distribution analysis / G. Di Lullo, F. Ieva, R. Longhi, A.M. Paganoni, M.P. Protti. - In: PLOS ONE. - ISSN 1932-6203. - 7:8(2012 Aug 07), p. e42340.e42340.

Estimating point and interval frequency of antigen-specific CD4+ T cells based on short in vitro expansion and improved poisson distribution analysis

F. Ieva
Secondo
;
2012

Abstract

Background: Knowledge of antigen-specific CD4+ T cells frequencies is pivotal to the choice of the antigen to be used in anti-viral and anti-tumor vaccination procedures and for monitoring of immune responses. Methods that employ small cell numbers from patient samples, are easy to perform and do not require complex techniques/instrumentations and therefore standardization are desirable. Methodology/Principal Findings: Purified blood CD4+ T cells from healthy donors were cultured with autologous antigen presenting cells in several replicate wells in equal numbers in the absence (un-stimulated wells) or in the presence of synthetic peptides corresponding to viral antigens promiscuous HLA-DR epitopes (antigen-stimulated wells). At day 7 of culture low dose IL-2 was added and at day 14 IFN-c and IL-5 release in the supernatant was measured. A statistical analysis approach, based on Poisson distribution, was then implemented to calculate the frequency of viral-specific CD4+ T cells. We first determined a patient-specific exceptionality threshold of cytokine release in the un-stimulated wells and then, based on this threshold, we counted the inactive/active wells within the antigen-stimulated wells. This number, along with the number of cells per well, allowed the point and interval estimates of frequencies. A ready-to-use Excel worksheet template with automatic calculations for frequencies estimate was developed and is provided as a supplemental file (Table S9). Conclusions/Significance: We report a simple experimental procedure combining short term in vitro cell culture with statistical analysis to calculate the frequency of antigen-specific CD4+ T cells. The detailed experimental procedure along with the Excel applicative are a valuable tool for monitoring immune responses in the clinical practice.
CD4 Lymphocyte Count ; CD4-Positive T-Lymphocytes ; Cell Proliferation ; Cells, Cultured ; Epitopes ; Epstein-Barr Virus Nuclear Antigens; Humans; Immunologic Memory; Interferon-gamma; Interleukin-5; Lymphocyte Activation; Poisson Distribution; Reproducibility of Results
Settore SECS-S/01 - Statistica
Settore MED/01 - Statistica Medica
Article (author)
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/233447
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