INDUCTION OF TH2 CYTOKINE EXPRESSION FOR P27-SPECIFIC IGA B-CELL RESPONSES AFTER TARGETED LYMPH-NODE IMMUNIZATION WITH SIMIAN IMMUNODEFICIENCY VIRUS-ANTIGENS IN RHESUS MACAQUES

To determine if there is an association between the isotype of simian immunodeficiency virus (SIV)-specific B cell responses and the profile of Th1 and Th2 cytokine expression, rhesus macaques were immunized wi th SIV antigens via the iliac lymph nodes, using a targeted lymph node (TLN) immunization procedure, When CD4(+) T cells purified from antig en-stimulated peripheral blood mononuclear cells were analyzed, the le vels of Th2 cytokine production were gradually increased after the sec ond and third immunizations, However, interferon-gamma production did not change, Analysis of SIV-specific B cell responses revealed that th e main isotype was IgG after the second and third immunizations, In ad dition, a peak of SIV-specific IgA B cell responses was noted followin g the third immunization, These findings suggest that the induction of Th2 type responses in TLN-immunized rhesus macaques reflects the sequ ence of initial induction of SIV-specific IgG-producing cells followed by IgA-secreting cells.