CpG-induced Th1-type response in the downmodulation of early development of allergy and inhibition of B7 expression on T cells of newborn mice.
BACKGROUND
Several differences have been described between neonatal and adult immune responses. The predisposition in early life to Th2-type response or tolerance makes it a susceptible period for infections and allergic sensitization.


OBJECTIVE
The aim of this work was to evaluate the effects of CpG-containing oligodeoxynucleotides on neonatal and adult immunization with ovalbumin and Blomia tropicalis extract and compare the CpG effects on B and T cells of neonatal and adult mice.


CONCLUSIONS
Mice that received CpG showed reduced immunoglobulin E (IgE) antibody production in both neonatal and adult periods, in parallel to increased IgG2a antibody levels. We observed that spleen cells of mice that received CpG in early life produced increased amounts of interferon-gamma upon anti-CD3 stimulation. Negative regulation of IgE response was more pronounced in adult than neonate mice; further, CpG decreased anaphylactic antiovalbumin IgG1 only in adults. Also, an upregulation of toll-like receptor 9 expression was detected in adult B cells, but not in neonatal, upon CpG stimuli. Neonatal B cells showed enhanced interleukin (IL)-10 expression and decreased IL-6 levels than adult B cells in response to CpG. When we analyzed in vitro activation of CD4+ T cells, an increased expression of B7 molecules on T cells in neonates was suppressed by CpG.


CONCLUSIONS
Altogether, we verified qualitative and quantitative evidences regarding CpG effect on neonatal and adult allergens immunizations, which points to the importance of understanding neonatal immune system to establish immunomodulatory strategies for prevention of allergic diseases.
de Brito
Cyro A
CA
Laboratory of Investigation in Dermatology and Immunodeficiencies, School of Medicine, University of São Paulo, São Paulo, Brazil.
Fusaro
Ana E
AE
Victor
Jefferson R
JR
Rigato
Paula O
PO
Goldoni
Adriana L
AL
Muniz
Bruno P
BP
Duarte
Alberto J S
AJ
Sato
Maria N
MN
D000818:Animals; D000831:Animals, Newborn; D039741:Antigens, Dermatophagoides / Q000008:administration & dosage; D001402:B-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D018122:B7-1 Antigen / Q000096:biosynthesis* / Q000235:genetics; D002457:Cell Extracts / Q000008:administration & dosage; D004247:DNA / Q000008:administration & dosage; D005260:Female; D006967:Hypersensitivity / Q000097:blood / Q000276:immunology*; D056724:Immunity, Humoral; D007114:Immunization; D007073:Immunoglobulin E / Q000097:blood; D051379:Mice; D008815:Mice, Inbred Strains; D009838:Oligodeoxyribonucleotides; D010047:Ovalbumin / Q000008:administration & dosage; D039981:Pyroglyphidae; D013601:T-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D051217:Toll-Like Receptor 9 / Q000096:biosynthesis* / Q000235:genetics
D039741:Antigens, Dermatophagoides; D018122:B7-1 Antigen; D002457:Cell Extracts; C423449:CpG ODN 1826; D009838:Oligodeoxyribonucleotides; D051217:Toll-Like Receptor 9; D007073:Immunoglobulin E; D010047:Ovalbumin; D004247:DNA