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Non-responsiveness to hepatitis B surface antigen vaccines is not caused by defective antigen presentation or a lack of B7 co-stimulation.
- Source :
-
Clinical & Experimental Immunology . Apr2005, Vol. 140 Issue 1, p126-137. 12p. - Publication Year :
- 2005
-
Abstract
- The mechanisms causing non-responsiveness to hepatitis B surface antigen (HBsAg) vaccines in man remain elusive. The increased incidence of non-responsiveness in subjects with HLA-DR3+ or -DR7+ haplotypes suggests that immune response mechanisms governed by genes of the MHC are involved. Homozygotes for these two haplotypes are found almost exclusively in the non-responder (NR) population. It is conceivable that antigen-presenting cells (APC) of NR are defective in the uptake of HBsAg and that they are unable to present this Ag adequately. Previously, we demonstrated thatDR2+,DR7+ andDP4+ NR were able to present HBsAg. In the present paper we demonstrate that six DR0301+ NR, five of which are homozygous for this marker, were able to take up, process and present HBsAg to HBsAg-specific, DR0301-restricted T cell lines. Non-fractionated peripheral blood mononuclear cells (PBMC) from the DR0301+ NR did not proliferate to HBsAgin vitro, whereas they proliferated vigorously upon stimulation with tetanus toxoid, thus ruling out the presence of a generalized immunodeficiency. We therefore conclude that HLA-DR0301+ NR vaccinees are not deficient in their HBsAg-presentation. Because it was demonstrated that recently activated T cells can apparently bypass the requirement for B7, we may have overlooked the role of the B7-co-stimulation in our set-up that used HBsAg-specific T cell lines. Therefore we examined the expression of B7 co-stimulatory molecules on NR-APC. CD86 was normally present on these cells and was not down-regulated after culturing the PBMC in the presence of HBsAg. We conclude that CD86 expression on CD14+ monocytes of DR0301- and DR07-homozygous poor responders is not deficient and cannot be the mechanism underlying the non-responsiveness of these subjects. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00099104
- Volume :
- 140
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Clinical & Experimental Immunology
- Publication Type :
- Academic Journal
- Accession number :
- 16370812
- Full Text :
- https://doi.org/10.1111/j.1365-2249.2004.02749.x