Systemic and mucosal immunity in rhesus macaques immunized with HIV-1 peptide and gp120 conjugated to Brucella abortus.

HIV vaccine testing in primates is an important method for determining the possibility of vaccine benefit in humans. Goals of HIV-1 vaccination include establishing neutralizing antibodies and a strong CD8(+) T-cell response. We tested a novel vaccine conjugate for its ability to elicit relevant immune responses to HIV proteins and peptides in rhesus macaques.

Mucosal immunity in mice immunized with HIV-1 peptide conjugated to Brucella abortus.

We have previously shown that a V3-loop peptide from HIV-1 envelope conjugated to heat-inactivated Brucella abortus (Ba) (V3-Ba) is capable of inducing antibodies that neutralize HIV-1 and cytotoxic T cells (CTL) that kill HIV-1-infected targets, even in mice that lack CD4(+) T cells. In this paper we show that intranasal (i.n.

Monophosphoryl lipid A behaves as a T-cell-independent type 1 carrier for hapten-specific antibody responses in mice.

It is known that the lipopolysaccharide (LPS) of gram-negative bacteria, in addition to being a potent adjuvant, is an effective carrier for covalently associated haptens. However, the toxic nature of most forms of LPS precludes their use as adjuvants or carriers for human vaccines. 4'-Monophosphoryl lipid A (MLA), a derivative of LPS with attenuated toxicity, is currently being tested in humans as an immunological adjuvant.

Lipopolysaccharide from Brucella abortus behaves as a T-cell-independent type 1 carrier in murine antigen-specific antibody responses.

In order to determine the carrier nature of lipopolysaccharide from Brucella abortus (LPS-BA) in evoking humoral responses, normal and immunodeficient mice were immunized with trinitrophenyl (TNP)-conjugated LPS-BA (TNP-LPS-BA) and the responses were compared with those to known T-dependent and T-independent antigens. TNP-LPS-BA, like T-independent type 1 (TI-1) antigens such as TNP-BA and TNP-LPS from Escherichia coli (TNP-LPS-EC), generated anti-TNP responses in BALB/c, athymic BALB/c nu/nu, and CBA/N mice. In contrast, N-2,4-dinitrophenyl-beta-alanylglycylglycyl-substituted keyhole limpet hemocyanin, a typical T-dependent antigen, was not immunogenic in athymic mice, and TNP-Ficoll (T-independent type 2) was ineffective in eliciting humoral responses in CBA/N mice.

Lipopolysaccharide (LPS) from Brucella abortus is less toxic than that from Escherichia coli, suggesting the possible use of B. abortus or LPS from B. abortus as a carrier in vaccines.

Brucella abortus may be useful as a component of vaccines. This is because it possesses several unique properties as a carrier that enable it to stimulate human B cells even in the relative absence of T cells. Human immunodeficiency virus type 1 proteins conjugated to B.