ABSTRACT
This study investigated memory responses in immune mice spleen cells to brucellosis by gene expression utilizing cDNA micro arrays. Out of a total of 1176 cDNA's 21 genes were differentially regulated in three independent experiments, and generally supported a Th1 type immune response. 10 genes were validated by real time PCR, and 3 genes (CD 86, CD 40 L and CD 132) were also analyzed by Flow Cytometry for surface protein expression. We extended these findings by studying the expression of five selected genes (IRF 1, SOCS 1, IL 2 R, IRF 7, and CXCR 4) in two independent groups of Brucella immunized mice. In this study we show the potential application of utilizing gene arrays to identify and establish new correlates of protection against a cell mediated immune response.
Subject(s)
Brucella/immunology , Brucellosis/immunology , Gene Expression Regulation , Immunologic Memory/genetics , Spleen/cytology , Animals , Carrier Proteins/genetics , Carrier Proteins/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Gene Expression Profiling , Humans , Interferon Regulatory Factor-1 , Interferon Regulatory Factor-7 , Interleukin Receptor Common gamma Subunit , Mice , Molecular Sequence Data , Oligonucleotide Array Sequence Analysis , Phenotype , Phosphoproteins/genetics , Phosphoproteins/metabolism , Receptors, CXCR4/genetics , Receptors, CXCR4/metabolism , Receptors, Interleukin-2/genetics , Receptors, Interleukin-2/metabolism , Repressor Proteins/genetics , Repressor Proteins/metabolism , Reproducibility of Results , Spleen/immunology , Suppressor of Cytokine Signaling 1 Protein , Suppressor of Cytokine Signaling ProteinsABSTRACT
Human brucellosis can be acquired from infected animal tissues by ingestion, inhalation, or contamination of conjunctiva or traumatized skin by infected animal products. In addition, Brucella is recognized as a biowarfare threat agent. Although a vaccine to protect humans from natural or deliberate infection could be useful, vaccines presently used in animals are unsuitable for human use. We tested orally administered live, attenuated, purine auxotrophic B. melitensis WR201 bacteria for their ability to elicit cellular and humoral immune responses and to protect mice against intranasal challenge with B. melitensis 16M bacteria. Immunized mice made serum antibody to lipopolysaccharide and non-O-polysaccharide antigens. Splenocytes from immunized animals released interleukin-2 and gamma interferon when grown in cultures with Brucella antigens. Immunization led to protection from disseminated infection and enhanced clearance of the challenge inoculum from the lungs. Optimal protection required administration of live bacteria, was related to immunizing dose, and was enhanced by booster immunization. These results establish the usefulness of oral vaccination against respiratory challenge with virulent Brucella and suggest that WR201 should be further investigated as a vaccine to prevent human brucellosis.
