N. meningitidis membrane vesicles elicited antibody responses in mice.

2004 JUL 7 - (NewsRx.com & NewsRx.net) -- Intranasal immunization with native and detergent-extracted outer membrane vesicles from Neisseria meningitidis elicited local and systemic antibody responses in mice.

"The mouse humoral immune response toward native or detergent-extracted outer membrane vesicles (NOMVs and DOMVs, respectively) from Neisseria meningitidis was determined after intranasal immunization. Both preparations elicited high frequencies of NOMV-specific antibody-forming cells (AFCs) locally in the nasal associated lymphoid tissue (NALT) after three or four weekly doses. The diffuse NALT (D-NALT) contained (approx)10-fold more NOW-specific AFCs than those observed in the mediastinal lymph node, spleen, and bone marrow," researchers in England report.

"AFCs observed in the D-NALT were primarily immunoglobulin A positive (IgA+) and were maintained for at least 1 month," said Terry Guthrie and colleagues at the Edward Jenner Institute for Vaccine Research. "In contrast, the organized NALT (O-NALT) contained low numbers of AFCs, and the response was relatively short-lived. In other lymphoid tissues, AFCs producing various IgG subclasses and IgM were present with IgG2b-producing AFCs being dominant or codominant with IgA or IgG2a. In serum and in all of the tissues examined, with the exception of the NALT, NOMVs clearly induced a stronger antibody response and a broader range of antibody isotypes than DOMVs."

"The development ...