Neonatal BCG vaccination induces IL-10 production by CD4+ CD25+ T cells.
To determine the optimal time of Bacillus Calmette-Guerin (BCG) vaccination for induction of Th1 immunity, we measured the interferon (IFN)-γ and interleukin (IL)-10 secretion in purified protein derivative (PPD)-stimulated peripheral blood mononuclear cell (PBMC) cultures in newborns vaccinated at birth or 2nd month of life. Moreover, role of CD4(+) CD25(+) T cells was studied by depletion assay at 8th month. Nineteen term and healthy newborns were randomized into two groups: Group I composed of 10 newborns vaccinated with BCG at birth and the remaining 9 (group II) at 2nd month of life. PBMCs were isolated at birth, 2nd and 8th months of age, and PPD-stimulated IL-10, 5 and IFN-γ secretion were assessed. The same measurements were repeated for IL-10 and IFN-γ after the depletion of CD4(+) CD25(+) T cells at the 8th month. Children vaccinated at birth demonstrated higher PPD-stimulated IFN-γ and IL-10 levels at 2 months of age when compared to non-vaccinated ones (p = 0.038 and p = 0.022, respectively), whereas at 8 months, no significant differences were detected between the two groups. Moreover, CD4(+) CD25(+)-depleted T-cell cultures resulted in lower PPD-stimulated IL-10 levels in those vaccinated at birth when compared to non-depleted condition at the 8th month (p < 0.001). BCG at birth upregulated PPD-stimulated IFN-γ secretion at the 2nd month and remained still detectable at 8 month after the vaccination, whereas those vaccinated at the 2nd month of life lacked that increase in IFN-γ response at the same time-point. Furthermore, depletion assays suggest that CD4(+) CD25(+) T cells are involved in PPD-stimulated IL-10 secretion in response to BCG vaccination.
Pediatric Allergy & Immunology, Faculty of Medicine, Marmara University, Istanbul, Turkey.
Tunc
T
Akkoc
Metin
M
Aydogan
Aysegul
A
Yildiz
Elif
E
Karakoc-Aydiner
Aarif
A
Eifan
Sevgi
S
Keles
Mustafa
M
Akin
Sultan
S
Kavuncuoglu
Nerin N
NN
Bahceciler
Isil B
IB
Barlan
D001500:BCG Vaccine; D015704:CD4 Antigens / Q000096:biosynthesis; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007371:Interferon-gamma / Q000096:biosynthesis / Q000235:genetics; D016753:Interleukin-10 / Q000096:biosynthesis* / Q000235:genetics; D053645:Interleukin-2 Receptor alpha Subunit / Q000096:biosynthesis; D008212:Lymphocyte Depletion; D008297:Male; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D014373:Tuberculin / Q000276:immunology / Q000378:metabolism; D014611:Vaccination
D001500:BCG Vaccine; D015704:CD4 Antigens; D053645:Interleukin-2 Receptor alpha Subunit; D014373:Tuberculin; D016753:Interleukin-10; D007371:Interferon-gamma