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J van den Bogaerde

Publications and source records attributed to J van den Bogaerde.

10 recordsLinked to original sources
PubMed1991

T-cell development in the fetus and the invariant series hypothesis.

Comparison of the timing of appearance of certain T-cell markers in the intrathymic development of T cells during gestation reveals a common sequence of expression in several species. Here Richard Aspinall and colleagues put forward a hypothesis concerning this 'invariant series' of markers that shares the same timing of expression across species barriers. It is proposed that T-cell markers that are members of the invariant series are very important in deciding the fate of a developing thymocyte.

Animals↗
PubMed1991

Xenogeneic responses in vitro in the Syrian hamster, Mesocricetus auratus. I. Evidence for a normal T cell repertoire.

We have investigated the ability of Syrian hamster lymphocytes to generate cytotoxic responses against classical MHC molecules on xenogeneic cells. Our data show that hamster lymph node cells can be stimulated in an in vitro primary mixed lymphocyte culture by irradiated rat or mouse lymphoid cells to produce a substantial cytotoxic response assayed on 51Cr-labelled xenogeneic blasts. Using congenic recombinant rat and mouse targets, the specificity of the cytotoxic activity could be localized to genetic regions known to determine classical class I histocompatibility antigens in these two species. In addition, specific cytotoxicity could be demonstrated on transfectant target cells expressing only the relevant rat class I molecules, and specific cytotoxicity could be inhibited by a monoclonal antibody specific for a rat classical class I molecule. Elimination of B cells did not affect the ability of the responder population to generate xenogeneic cytotoxicity. In further experiments it was shown that hamster xenogeneic killers could distinguish between two subtly modified forms of a rat classical class I molecule essentially as efficiently as can allogeneic rat killers. Finally, lymph node cells from female hamsters primed in vivo with male hamster cells were able to generate weak but significant male-specific cytotoxicity after boosting in vitro. In sum, our experiments show that the general outline of the cytotoxic T cell repertoire of the Syrian hamster is conventional. These results suggest that monomorphic class I molecules expressed by the Syrian hamster probably function normally to direct the differentiation of its cytotoxic T cell repertoire.

Animals↗
PubMed1991

Induction of long-term survival of hamster heart xenografts in rats.

The aim of this study was to determine the mechanisms responsible for concordant xenograft rejection using the hamster-to-rat heart graft model. Even though it was known that rat CD4 positive T cells proliferated to hamster stimulators in mixed lymphocyte reactions, the depletion of CD4 positive T cells in rat recipients did not lead to an extension of xenograft survival. Suppression of T cell immunity using other monoclonal antibodies or cyclosporine also failed to improve survival. Only by depleting complement with cobra-venom factor could hamster xenograft survival be prolonged, and long-term survival was achieved by combining CsA with COF. High-antibody titers to hamster cells were found after transplantation of hamster hearts, and evidence is presented that rejection of these "concordant" xenografts is mediated primarily by antibody-complement mechanisms. The antihamster antibodies were produced in the absence of T cell help, which suggests that antibody-mediated graft destruction cannot be inhibited by suppression or depletion of T cells. Pharmacologic depletion of complement for the clinical application of concordant xenografts is a promising avenue of future research.

Animals↗
PubMed1990

Concerted evolution of class I genes in the major histocompatibility complex of murine rodents.

Full-length cDNA sequences of two class I major histocompatibility complex molecules from the DA strain of Rattus norvegicus are reported. One codes for the classical class I restriction element RT1.Aa, which maps to the locus in the rat major histocompatibility complex homologous to H-2K in the mouse. The other probably codes for a soluble nonclassical class I molecule present in DA rat serum; a short deletion in the fifth exon implies that the translated product will terminate in the membrane-spanning region. These sequences have been compared with mouse classical class I sequences as well as with three published rat class I cDNA partial sequences. The results show, first, that "locus-specific" substitutions from the H-2K, H-2D, and H-2L data set are scrambled in the RT1.Aa molecule; a majority of these substitutions have H-2D/L-specific features. Second, the data show that the four rat sequences are strikingly similar to one another regardless of locus or haplotype of origin; they share a number of apparently species-specific features that distinguish them all from mouse classical class I sequences, which likewise share distinctive features of their own. The results suggest that segmental sequence exchange plays a major role in determining the evolution of sequence in class I major histocompatibility complex molecules.

Amino Acid Sequence↗
PubMed1990

Inhibition of T cell responses in vitro by an antibody against a novel lymphocyte surface molecule (QCA-1).

We have identified an antigen present on the surface of lymphocytes in the rat which appears to play an important role in the preliminary stages of the immune response. This antigen, which we have called quiescent cell antigen 1 because of its apparent expression only on quiescent cells, is present on the majority of peripheral T and B cells and a small percentage of thymocytes which are located mainly in the medullary region. SDS-PAGE analysis of membrane molecules shows two bands on unreduced gels at approximately 43 and 47 kd. On reduction the bands ran at approximately 46 and 60 kd. When a monoclonal antibody against this antigen (HIS45) is present in an allogeneic mixed leukocyte reaction, it inhibits the proliferation of responding cells completely. When the antibody HIS45 is added to cytotoxic T lymphocyte mediated lysis assays it does not inhibit lysis nor does it affect the specificity of this lysis. Comparison with other antibodies which have been reported to affect lymphocyte function in rats and in other species fail to reveal any which have similar properties.

Animals↗
PubMed1990

In vitro and in vivo effects of monoclonal antibodies against T cell subsets on allogeneic and xenogeneic responses in the rat.

The Syrian hamster-to-rat represents an example of a concordant species difference, and therefore organ transplants using the hamster as the donor and the rat as the recipient are not rejected hyperacutely, as in discordant species combinations. Cellular mechanisms of xenogeneic rejection of hamster hearts by rats were studied both in vitro and in vivo, using monoclonal antibodies to rat T cell antigens. The results of this study reveal that CD4-positive cells of rats proliferated in vitro to both allogeneic stimulators and xenogeneic stimulators from a concordant strain, but required accessory cells of the responder phenotype to proliferate to discordant human stimulators. Monoclonal antibody therapy was used to prevent graft rejection in allogeneic and xenogeneic species combinations, using the rat as the recipient. Treatment with anti-CD4 antibodies was effective in prolonging allograft survival across a full MHC mismatch. No rejection occurred during antibody therapy, and long-term graft survival was achieved in 1/3 of transplanted grafts. The same monoclonal antibody therapy led to increased survival of grafts from hamster donors, but all of these grafts were rejected during therapy, and no long-term graft survival was achieved. Anti-CD8 antibody therapy, combined with anti-CD4 did not improve survival of hamster hearts in rats. Addition of cyclosporine to the anti-CD4 regimen also did not improve graft survival. Injection of an anti-T cell receptor antibody was no better than the anti-CD4 antibody in prolonging the survival times of heart grafts from the concordant xenogeneic species. These data suggest that the rejection of concordant xenogeneic tissue is not wholly a T cell-dependent phenomenon.

Animals↗