Human peripheral blood T cells, monocytes, and macrophages secrete macrophage inflammatory proteins 1alpha and 1beta following stimulation with heat-inactivated Brucella abortus.
Heat-killed Brucella abortus (HBa) has been proposed as a carrier for therapeutic vaccines for individuals with immunodeficiency, due to its abilities to induce interleukin-2 (IL-2) and gamma interferon (IFN-gamma) in both CD4(+) and CD8(+) T cells and to upregulate antigen-presenting cell functions (including IL-12 production). In the current study, we investigated the ability of HBa or lipopolysaccharide isolated from HBa (LPS-Ba) to elicit beta-chemokines, known to bind to the human immunodeficiency virus type 1 (HIV-1) coreceptor CCR5 and to block viral cell entry. It was found that human peripheral blood mononuclear cells secreted beta-chemokines following stimulation with HBa, and this effect could not be blocked by anti-IFN-gamma neutralizing antibodies. Among purified T cells, macrophage inflammatory protein 1alpha and 1beta (MIP-1alpha and MIP-1beta, respectively) secretion was observed primarily in human CD8(+) T cells. The kinetics of beta-chemokine induction in T cells were slow (3 to 4 days). The majority of beta-chemokine-producing CD8(+) T cells also produced IFN-gamma following HBa stimulation, as determined by triple-color intracellular staining. A significant number of CD8(+) T cells contained stored MIP-1beta that was released after HBa stimulation. Both HBa and LPS-Ba stimulated high levels of MIP-1alpha and MIP-1beta production in elutriated monocytes and even higher levels in macrophages. In these cells, beta-chemokine mRNA was upregulated within 30 min and proteins were secreted within 4 h of stimulation. The monocyte- and macrophage-derived beta-chemokines were sufficient to block CCR5-dependent HIV-1 envelope-mediated cell fusion. These data suggest that, in addition to the ability of HBa to elicit antigen-specific humoral and cellular immune responses, HBa-conjugated HIV-1 proteins or peptides would also generate innate chemokines with antiviral activity that could limit local viral spread during vaccination in vivo.
Zaitseva
M
M
Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland 20892, USA.
King
L R
LR
Manischewitz
J
J
Dougan
M
M
Stevan
L
L
Golding
H
H
Golding
B
B
D016915:AIDS Vaccines / Q000276:immunology; D002003:Brucella abortus / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D015497:HIV-1 / Q000472:pathogenicity / Q000502:physiology; D006358:Hot Temperature; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology; D008213:Lymphocyte Activation; D019402:Macrophage Inflammatory Proteins / Q000096:biosynthesis*; D008264:Macrophages / Q000276:immunology; D008561:Membrane Fusion / Q000502:physiology; D009000:Monocytes / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
D016915:AIDS Vaccines; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D008070:Lipopolysaccharides; D019402:Macrophage Inflammatory Proteins