title: Impaired CD8(+) T cell responses upon Toll-like receptor activation in common variable immunodeficiency.
abstract: Infections caused by bacteria or viruses are frequent in common variable immunodeficiency (CVID) patients due to antibody deficiencies, which may be associated with altered T cell function. CVID patients are frequently in contact with pathogen-associated molecular patterns (PAMPs), leading to the activation of innate immunity through Toll-like receptors (TLR) affecting T cell activation. We evaluated the effect of TLR activation on T cells in CVID patients undergoing intravenous immunoglobulin (IVIg) replacement using synthetic ligands.
  
  
  
  Expression of exhaustion, activation and maturation markers on T cells from peripheral blood as well as regulatory T cells and follicular T cells in peripheral blood mononuclear cells (PBMCs) from CVID and healthy individuals were evaluated by flow cytometry. PBMCs cultured with TLR agonists were assessed for intracellular IFN-γ, TNF, IL-10, IL-17a or IL-22 secretion as monofunctional or polyfunctional T cells (simultaneous cytokine secretion) by flow cytometry.
  
  
  
  We found increased expression of the exhaustion marker PD-1 on effector memory CD4(+) T cells (CD45RA(-)CCR7(-)) in the peripheral blood and increased expression of CD38 in terminally differentiated CD8(+) T cells (CD45RA(+)CCR7(-)). Furthermore, a decreased frequency of naïve regulatory T cells (CD45RA(+)Foxp3(low)), but not of activated regulatory T cells (CD45RA(-)Foxp3(high)) was detected in CVID patients with splenomegaly, the non-infectious manifestation in this CVID cohort (43.7 %). Moreover, the frequency of peripheral blood follicular helper T cells (CD3(+)CD4(+)CXCR5(+)PD-1(+)ICOS(+)) was similar between the CVID and control groups. Upon in vitro TLR3 activation, a decreased frequency of CD8(+) T cells secreting IFN-γ, IL-17a or IL-22 was detected in the CVID group compared to the control group. However, a TLR7/TLR8 agonist and staphylococcal enterotoxin B induced an increased Th22/Tc22 (IL-22(+), IFN-γ(-), IL-17a(-)) response in CVID patients. Both TLR2 and TLR7/8/CL097 activation induced an increased response of CD4(+) T cells secreting three cytokines (IL-17a, IL-22 and TNF)in CVID patients, whereas CD8(+) T cells were unresponsive to these stimuli.
  
  
  
  The data show that despite the unresponsive profile of CD8(+) T cells to TLR activation, CD4(+) T cells and Tc22/Th22 cells are responsive, suggesting that activation of innate immunity by TLRs could be a strategy to stimulate CD4(+) T cells in CVID.
authors.affiliation: Laboratory of Dermatology and Immunodeficiencies, LIM-56, Department of Dermatology, Medical School, Tropical Medicine Institute, University of São Paulo, Av. Dr. Enéas de Carvalho Aguiar, 500, 3rd Floor, São Paulo, 05403-000, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: de Lollo
authors.affiliation: Laboratory of Dermatology and Immunodeficiencies, LIM-56, Department of Dermatology, Medical School, Tropical Medicine Institute, University of São Paulo, Av. Dr. Enéas de Carvalho Aguiar, 500, 3rd Floor, São Paulo, 05403-000, Brazil.
authors.forename: Dewton
authors.initials: D
authors.lastname: de Moraes Vasconcelos
authors.affiliation: Laboratory of Dermatology and Immunodeficiencies, LIM-56, Department of Dermatology, Medical School, Tropical Medicine Institute, University of São Paulo, Av. Dr. Enéas de Carvalho Aguiar, 500, 3rd Floor, São Paulo, 05403-000, Brazil.
authors.forename: Luanda Mara
authors.initials: LM
authors.lastname: da Silva Oliveira
authors.affiliation: Laboratory of Dermatology and Immunodeficiencies, LIM-56, Department of Dermatology, Medical School, Tropical Medicine Institute, University of São Paulo, Av. Dr. Enéas de Carvalho Aguiar, 500, 3rd Floor, São Paulo, 05403-000, Brazil.
authors.forename: Tiago
authors.initials: T
authors.lastname: de Oliveira Titz
authors.affiliation: Department of Pediatrics, Medical School, University of São Paulo, São Paulo, Brazil.
authors.forename: Magda
authors.initials: M
authors.lastname: Carneiro-Sampaio
authors.affiliation: Department of Pediatrics, Medical School, University of São Paulo, São Paulo, Brazil.
authors.forename: Cristina Miuki Abe
authors.initials: CM
authors.lastname: Jacob
authors.affiliation: Laboratory of Dermatology and Immunodeficiencies, LIM-56, Department of Dermatology, Medical School, Tropical Medicine Institute, University of São Paulo, Av. Dr. Enéas de Carvalho Aguiar, 500, 3rd Floor, São Paulo, 05403-000, Brazil.
authors.forename: Alberto José
authors.initials: AJ
authors.lastname: da Silva Duarte
authors.affiliation: Laboratory of Dermatology and Immunodeficiencies, LIM-56, Department of Dermatology, Medical School, Tropical Medicine Institute, University of São Paulo, Av. Dr. Enéas de Carvalho Aguiar, 500, 3rd Floor, São Paulo, 05403-000, Brazil. marisato@usp.br.
authors.forename: Maria Notomi
authors.initials: MN
authors.lastname: Sato
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000378:metabolism; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D017074:Common Variable Immunodeficiency / Q000276:immunology*; D016207:Cytokines / Q000378:metabolism; D003710:Demography; D005260:Female; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D051193:Toll-Like Receptors / Q000819:agonists / Q000378:metabolism*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D016207:Cytokines; D051193:Toll-Like Receptors; D051997:ADP-ribosyl Cyclase 1
keywords: Common variable immunodeficiency; Exhaustion and activation markers; Polyfunctional T cells; Tc22/Th22; Toll-like receptor agonists