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J Rozing

Publications and source records attributed to J Rozing.

At least 55 records · Page 3Linked to original sources
PubMed1992

T cell receptor V beta variable gene family expression in human peripheral blood lymphocytes at the mRNA and membrane protein level.

A polymerase chain reaction (PCR) was developed, using combinations of an oligonucleotide primer for a T cell receptor V beta gene family and one for the constant C beta gene segments, to assess the expression of each of 20 V beta gene families in RNA after reverse transcription into cDNA. The detection was done after agarose gel electrophoresis of PCR products and ethidium bromide staining. The positive identification of the PCR products was done by hybridization with a J beta oligonucleotide probe. For T cell lines, a signal was observed in the V beta 8 combination for Jurkat cells, V beta 5a in HSB cells, V beta 2 and V beta 12a in Molt-3 cells and V beta 2, V beta 5a and V beta 12a in Molt-4 cells. Using mixtures of RNA from different cell lines, the sensitivity of the method was in the range of 0.1-0.5%. In peripheral blood mononuclear cells from four donors, taken at three different occasions, all V beta families were detectable. The intensity of the PCR product varied between various V beta gene families. Flow cytometric analysis of blood mononuclear cells from the same donors with a restricted series of V beta gene family-specific antibodies also revealed the presence of all families. The approach to assess V beta gene family expression in heterogeneous populations opens the possibility to study T cell receptor variable gene expression in relation to physiology and pathologic processes.

Base Sequence↗
PubMed1992

The involvement of the intestinal microflora in the expansion of CD4+ T cells with a naive phenotype in the periphery.

It is well known that immune reactivity declines with age. Recently, we demonstrated that the age-related decrease in IL-2 production by CD4+ T cells was accompanied by an increased production of IL-4 and interferon-gamma (IFN-gamma). This age-related shift in the profile of lymphokine production was related to phenotypic changes within the CD4+ T-cell subset, that is, a decrease in the percentage of CD45RB++ CD4+ T cells and an increase in the percentage of Pgp-1+ CD4+ T cells. To study whether these age-related changes were due to previous antigenic exposure, we performed a phenotypic and functional analysis on splenic CD4+ T cells isolated from individual germ-free (GF), specific pathogen-free (SPF), and clean conventional (CC) mice. Interestingly, the total number of splenic CD4+ T cells in GF mice was twofold lower as compared to age-matched SPF or CC mice, regardless whether mice were analyzed at young (10 weeks) or at advanced age (13-14 months). Unexpectedly, the phenotypic composition of the CD4+ T-cell subset was comparable in the GF, SPF, and CC mice as determined by the expression of CD45RB and Pgp-1, indicating that CD4+ T cells with a naive phenotype (CD45RB++ Pgp-1-) were not enriched in GF mice. Moreover, at an age of 13-14 months, CD4+ T cells from GF mice frequently produced more IL-4 and IFN-gamma than their CC counterparts. These lymphokine data showed, therefore, that a relatively high proportion of CD4+ T cells with a memory phenotype can also be defined in GF mice on the basis of their function. The contamination of GF mice with a colonization resistant factor (CRF flora) resulted in twofold higher numbers of splenic CD4+ T cells. Surprisingly, not only CD4+ T cells with a memory phenotype (CD45RB-/+ Pgp-1++) had expanded, but also CD4+ T cells with a naive (CD45RB++ Pgp-1-) phenotype. Our results, therefore, strongly suggest that the expansion of naive CD4+ T cells in the periphery is mediated by the intestinal microflora.

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PubMed1992

V beta gene family usage in spontaneous lymphomas of AKR mice: evidence for defective clonal deletion.

T-cell receptor (TCR) beta-chain usage and expression of the CD3, CD4, and CD8 differentiation antigens were analyzed in 14 spontaneous AKR lymphomas. Lymphoma cells massively infiltrated and/or proliferated in the organs analyzed (thymus, spleen, and mesenteric lymph nodes), giving rise to a loss of organ structure. One lymphoma occurred only in the thymus, and failed to express CD3, CD4, and CD8. All other lymphomas expressed the CD3/TCR complex. With respect to CD4 and CD8 expression, the lymphomas were either double-negative (DN), double-positive (DP), or single-positive (SP). The frequency of DP (CD4+8+) lymphomas was low compared to the frequency of DP thymocytes in a normal AKR thymus. A substantial heterogeneity was seen in the intensity of CD4 and CD8 expression among various lymphomas, which was independent of the level of CD3 expression. Considering TCR V beta gene family usage, 2 out of 14 lymphomas expressed V beta 6. Normally, V beta 6+ thymocytes are deleted from the thymocyte pool at the immature DP stage of T-cell development in AKR mice. These data support the hypothesis that the lymphocytes in the immature DP stage of T-cell development are susceptible to the induction of AKR lymphomagenesis. The presence of V beta 6+ lymphoma cells indicates that the lymphomagenesis is accompanied by a defective clonal deletion of cells expressing a possible autoreactive TCR.

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PubMed1991

Susceptibility to the induction of either autoimmunity or immunosuppression by mercuric chloride is related to the major histocompatibility complex class II haplotype.

Mercuric chloride (HgCl2) induces in Brown Norway rats a CD4+ T lymphocyte-dependent systemic autoimmune syndrome, involving synthesis of anti-glomerular basement membrane autoantibodies and development of proteinuria. Lewis rats are resistant to HgCl2-induced autoantibody production and, in contrast, develop immunosuppression, mediated by CD8+ T lymphocytes. In the present study, genetic requirements governing autoreactivity or immunosuppression in response to HgCl2 were further explored. Both major histocompatibility complex (MHC) and non-MHC genes are involved in determining susceptibility to HgCl2-induced autoimmunity. Both AO (RT1u) and DZB (RT1u) rats were found to develop a membranous autoimmune glomerulopathy upon exposure to HgCl2. Only the DZB strain, which differs in part of the non-MHC background from AO, developed proteinuria. AO.1P (RT1.AuB1D1Eu) rats, which are genetically identical to AO except for the Lewis haplotype at the MHC class II loci, appeared to develop immunosuppression upon exposure to HgCl2. It is concluded that autoreactivity and immunosuppression, induced by HgCl2, are both dependent on the MHC class II haplotype. In autoimmune responder strains the type of autoimmune glomerulopathy is influenced by non-MHC genes.

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PubMed1991

Experimental autoallergic sialadenitis in the LEW rat. I. Parameters of disease induction.

Experimental autoallergic sialadenitis (EAS) is an autoimmune mononuclear cell infiltration of the submandibular salivary gland that results in tissue destruction and glandular dysfunction. A previous report has described an animal model of induced EAS in LEW rats following sensitization with allogeneic WF submandibular gland (SMG). The present study extends this observation to an EAS disease model induced following sensitization of LEW rats with syngeneic LEW SMG. Furthermore, we describe the characterization of the mononuclear cells in the glandular infiltrates, evaluate the production of autoantibodies, and establish the parameters important for reproducible induction of EAS. Our results demonstrate that EAS can be induced in a completely syngeneic system and the histopathology of disease induction in the syngeneic and allogeneic model systems is similar. Helper/inducer (CD4+) and suppressor/cytotoxic (CD8+) T-cell subsets are the dominant cell types in the salivary mononuclear cell infiltrate. An anti-duct autoantibody was found in the serum of virtually all LEW rats with EAS. Although closely associated with disease development, the presence of this antibody was not a prerequisite for development of histopathologic disease. Induction of disease in both the syngeneic and allogeneic models of EAS is dependent upon administration of Bordetella pertussis at the time of sensitization. Finally, the histopathology of the cellular infiltrates in both the allogeneic and syngeneic models of EAS resemble those observed in the salivary tissues of Sjögren's patients. While there are several differences between EAS in the LEW rat and the full expression of Sjögren's syndrome, EAS may serve as a model to study the salivary gland component of this complex human disease.

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PubMed1991

Transplantation of purified islet cells in diabetic rats. I. Standardization of islet cell grafts.

A standardized procedure was developed for the preparation of rat islet cell grafts with selected cell number and composition. After collagenase digestion of pancreases and elutriation of tissue fragments, islets were isolated and dissociated, and cells were purified by autofluorescence-activated cell sorting. Approximately 30% of the initial beta-cell mass was lost during digestion and elimination of small mostly exocrine particles. Fifty percent was recovered in isolated islet preparations and 30% in the purified beta-cell suspensions of greater than 95% purity and viability. Sorting according to cellular flavin adenine dinucleotide content discriminated islet beta-cells from islet endocrine non-beta-cells, fibroblasts, leukocytes, and exocrine cells. Purified endocrine islet cell grafts were prepared by aggregating 10(6) pure beta-cells with or without 8 x 10(5) pure endocrine non-beta-cells. In contrast to intact islets, the purified aggregates were devoid of nonendocrine and damaged cells. Intraportal implantation of a pure beta-cell graft rapidly and permanently normalized the diabetic state of streptozocin-administered animals. The standardized preparation of purified beta-cell grafts allows us to address several metabolic and immunological questions concerning islet cell transplantation in diabetes.

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PubMed1991

Two opposing modes of action of beta-endorphin on lymphocyte function.

Five opioid peptides (alpha-, beta-, and gamma-endorphin, methionine- and leucine-enkephalin) were tested for their effect on the concanavalin A-induced proliferative response of splenocytes of adult male F344 rats. The continuous presence of these opioid peptides during culture of T cells did not affect proliferation. However, 30 min of preincubation with beta-endorphin (beta-end), but not with the other opioid peptides, resulted in a dose-dependent enhancement of proliferation of 50-100%. This potentiating effect of beta-end on proliferation was preceded by an increase in the production of interleukin-2 (IL-2) and in the extent of IL-2 receptor expression. The stimulatory effect of beta-end was not prevented by naloxone, indicating that classical opioid receptors were not involved. The continuous presence of beta-end (or alpha-end) in cultures of cells that had been preincubated with beta-end completely abolished the stimulatory effect, pointing towards the potential of beta-end to regulate T-cell function via different mechanisms.

Animals↗
PubMed1990

A decreased functional capacity of CD4+ T cells underlies the impaired DTH reactivity in old mice.

The data presented in this paper show that the in vivo delayed-type-hypersensitivity (DTH) reaction to both H-2 and non-H-2 alloantigens declines with increasing age. It is also shown that cells generated in vitro are capable to transfer DTH to young naive syngeneic recipients. Using this in vitro system it could be demonstrated that cells from old CBA/Rij mice induced lower DTH responses than cells from young CBA/Rij mice. Depletion experiments with the effector T cell population showed that the DTH effector phase is mediated by CD4+ T cells. Lower responses in old mice were not due to increased CD8+ suppressor T cell activity, since after removal of the CD8+ T cells old CD4+ cells were still less effective in the generation of DTH effector T cells than young CD4+ cells. Addition of IL-2 containing supernatant to in vitro cultures did not improve the subsequent DTH response. From these data it can be concluded that the reduced DTH responses in old mice are not solely due to CD8+ suppressor cell activity and/or lack of IL-2, but that rather intrinsic defects of the CD4+ T cell population appear to play a major role in the impaired DTH reactivity during ageing.

Aging↗
PubMed1990

Impairment of CD3-dependent and CD3-independent activation pathways in CD4+ and in CD8+ T cells from old CBA/RIJ mice.

Stimulation of T cells from old mice with anti-CD3 antibodies resulted in a high variability of proliferative responses, which were 2- to 8-fold lower than the responses by T cells from young mice, even in the presence of exogenous rIL-2. Moreover, the CD4+ T cells from these old mice displayed a diminished capacity to produce IL-2 in response to anti-CD3. A partial explanation was found in the observation that T cells from the majority of old mice displayed a diminished expression of CD3 of variable intensity. However, after stimulation of the T cells with the combination of phorbol-12-myristate-13-acetate (PMA) and ionomycin to bypass CD3, 3 out of 6 old mice still exhibited 2-fold lower proliferative responses than T cells from young mice; IL-2 production by the CD4+ T cells was lower in all old mice tested. Comparison of CD4+ T cells and CD8+ T cells from old mice revealed a defective PMA/ionomycin response in both subsets, although this defect seemed more pronounced in CD4+ T cells when compared with the young counterparts. The diminished response of CD8+ T cells was accompanied by a diminished expression of the IL-2R alpha-chain. In contrast, old CD4+ T cells expressed rather higher levels of IL-2R alpha-chain than young CD4+ T cells. Altogether, multiple defects which are not necessarily the same in CD4+ and CD8+ T cells are responsible for defective T cell responses in old mice.

Aging↗
PubMed1990

Analysis of the age-related decline in alloreactivity of CD4+ and CD8+ T cells in CBA/RIJ mice.

CD4+ T cells from healthy old CBA/Rij mice were studied for their ability to respond to alloantigens by IL-2 production and proliferation. IL-2 production by these purified cells in response to BALB/c spleen cells was about 4 times lower than the IL-2 production (50 U/ml) by CD4+ T cells from young mice. After stimulation with concanavalin A only a two-fold difference in IL-2 production was found. The extent of proliferation by CD4+ T cells from old mice in response to allogeneic cells was at least 4 times lower than that by the cells from young mice. This difference was not influenced by the addition of IL-2 containing conditioned medium (CM). Proliferative responses by CD8+ T cells were only found after the addition of CM and then the response by cells from old mice was 2-10 times lower than the response by cells from young mice. Limiting dilution analysis of the separate T cell subpopulations showed that these low responses to alloantigens by cells from old mice were only in part due to a decline in the frequency of antigen-specific CD4+ or CD8+ T cells. As far as old CD8+ T cells were concerned, an additional explanation for the low responsiveness was found in a diminished expression of the IL-2 receptor (IL-2R) alpha-chain. However, CD4+ T cells from old mice expressed normal levels of IL-2R alpha-chain. The observation that proliferative responses by CD4+ T cells may be low, despite a normal frequency of antigen-specific cells, an apparently normal IL-2R expression and despite the presence of exogenous IL-2, indicates that CD4+ T cells from old mice are not only impaired in their ability to produce IL-2, but are also impaired in their ability to handle the IL-2 signal.

Aging↗
PubMed1990

Phenotype of intraepithelial lymphocytes in euthymic and athymic mice: implications for differentiation of cells bearing a CD3-associated gamma delta T cell receptor.

This study was carried out to determine the exact phenotype of intraepithelial lymphocytes (IEL) in euthymic and athymic nude mice. The phenotype of IEL in euthymic and athymic mice is mainly CD3+CD8+. However, based on Thy-1- and CD3-associated receptor expression we can subdivide the CD3CD8 population into different subpopulations in euthymic and athymic mice. In euthymic and athymic mice several CD3CD8 populations can be defined. One population expressing Thy-1 and the T cell receptor (TcR) alpha beta is absent in athymic mice. Two other CD3+CD8+ populations can be detected in euthymic and athymic mice. Based on Northern blot and flow cytometric analysis we have to conclude that these populations express the CD3-associated TcR gamma delta. One of the TcR gamma delta-expressing populations also expresses Thy-1 at low surface density. This is in contrast to the CD3CD8 population expressing the TcR alpha beta, which expresses Thy-1 at high surface density. There are also, however, especially in athymic nude mice, significant numbers of CD3-CD8+ cells present with the same localization as IEL. The function of these cells is yet unknown. Using a probe for the delta chain we have shown that IEL preferentially express 2-kb mRNA, while nearly no delta chain 1.7-kb mRNA is expressed by these cells. This is in contrast to delta mRNA in thymocytes. Equal quantities of the 1.7- and 2.0-kb delta chain mRNA species were found in RNA isolated from thymocytes. The results imply that CD3+CD8+ intestinal IEL expressing the CD3-associated TcR gamma delta can differentiate in absence of the thymus and represent a thymus-independent lineage of cells bearing this receptor.

Animals↗
PubMed1990

Immunotoxicity of bis(tri-n-butyltin)oxide in the rat: effects on thymus-dependent immunity and on nonspecific resistance following long-term exposure in young versus aged rats.

To investigate whether immune function suppression observed in an earlier study after short-term bis(tri-n-butyltin)oxide (TBTO) exposure also occurred after long-term treatment, function studies for specific and nonspecific resistance were performed after exposure of weaned male rats to diets containing 0, 0.5, 5, or 50 mg TBTO/kg for 4-6 and 15-17 months. Treatment for 4.5 months had no effect on body weight but reduced thymus weight at 50 mg/kg. Regarding the thymus-dependent immunity, delayed-type hypersensitivity reactions to ovalbumin and tuberculin were not depressed, in contrast to the results of the short-term study. The resistance to the nematode Trichinella spiralis was dose-relatedly suppressed at the 5 and 50 mg/kg levels, in both experiments (5.5 and 16.5 months exposure), as shown by increased counts of muscle larvae and depressed serum IgE titers. Also the inflammatory reaction around cysts in parasitized musculature was reduced. No significant reduction was found in IgM and IgG titers to T. spiralis, ovalbumin, and sheep red blood cells as determined by enzyme-linked immunosorbent assay. TBTO exposure at 50 mg/kg for 4.5 months significantly reduced thymus weight, but the response of thymocytes to T-cell mitogens was unaltered. TBTO treatment for 4.5 or 16 months did not influence the response of spleen cells to T-and B-cell mitogens and neither influenced spleen weight. A dose-related shift was observed in T- and B- cell numbers in mesenteric lymph nodes as shown by flow cytometry using monoclonal antibodies: treatment for 6 and 18 months reduced the relative count of T-lymphocytes and consequently increased the percentage of B-lymphocytes. As a result, the T:B ratio was reduced in the 5 and 50 mg/kg groups. Concerning the nonspecific resistance, TBTO exposure for 5 and 17 months reduced macrophage function at 50 mg/kg as shown by impaired splenic clearance of Listeria monocytogenes bacteria. Natural cell-mediated cytotoxicity of spleen and peritoneal cells was investigated in a 51Cr-release assay with YAC-lymphoma target cells. TBTO treatment significantly suppressed natural killer (NK) activity in spleen cells. Significant suppression was noted in all treatment groups following 16 months TBTO exposure; in contrast to treatment for 4.5 months. No significant alterations were observed in the spontaneous cytotoxicity of nonadherent and adherent peritoneal cells following 4.5 months treatment. Treatment of aged (i.e., 1-year-old) male rats for 5 months with the 50 mg/kg diet reduced thymus weight but had no effect on body or spleen weight.(ABSTRACT TRUNCATED AT 400 WORDS)

Aging↗
PubMed1990

Adoptive transfer of autoimmune diabetes and thyroiditis to athymic rats.

We describe the induction of autoimmune diabetes, insulitis, and thyroiditis in athymic rats following injections of major histocompatibility complex compatible spleen cells. Lymphocytes with these capabilities were found in normal rats of the YOS, WAG, PVG, and diabetes-resistant BB strains, and in diabetes-prone BB rats. Adoptive transfer was facilitated by prior in vivo depletion of RT6.1+ regulatory T cells and in vitro mitogen activation of donor spleen cells. By RT6 depleting diabetes-resistant donors and using nude recipients, transfer of diabetes and thyroiditis was accomplished by using fresh, unstimulated spleen cells. The data suggest that organ-specific autoreactive cells may be present to various degrees but suppressed to a variable extent in many rat strains. The equilibrium between autoreactive and regulatory cells appears to determine the expression of autoimmunity.

Animals↗
PubMed1990

Vascular thymus transplantation in rats. Technique, morphology, and function.

A new method of thymus transplantation is introduced, in which the graft is directly connected with the recipient's vascular system. This procedure was used both in euthymic rats and congenitally athymic nude rats. At all tested intervals after transplantation thymus grafts hardly differed from the recipient's own thymus in immunohistology and lymphocyte yield. In athymic nude rats, T cell-dependent immunity, tested by mitogen- and alloantigen-induced T cell responses, as well as by antibody production and delayed-type hypersensitivity after ovalbumin administration, showed that vascular thymus grafts could generate T cell functions to euthymic control levels. We conclude that the technique of vascular thymus transplantation represents a valuable tool, either in fundamental research on thymus function, or for the purpose of immune (re)constitution.

Animals↗
PubMed1989

Localization and phenotype of CD3 associated gamma/delta receptor expressing intestinal intraepithelial lymphocytes.

This study was carried out to determine the exact phenotype and localization of intestinal intra epithelial lymphocytes (IEL). IEL reside in the small intestine between or just beneath the epithelial cell layer which covers the lamina propria. These CD3 positive cells were found in equal numbers at this location both in the villi as well as in the crypts. The majority of these cells express a CD3 associated gamma delta receptor. Cell surface marker analysis of isolated IEL reveals high percentages of cells expressing CD8 and/or Thy-1. No CD4 positive cells could be detected in significant numbers. Equal quantities of IEL could be isolated from the intestine of athymic (nude) mice. Although the percentage of CD3 positive cells in the IEL from nude mice was lower than the figures obtained from euthymic mice northern blot analysis revealed a strong expression of gamma delta message in the IEL of nude mice. In the CD3 positive IEL fraction of nude mice the relative contribution of the CD8 positive cells remained unchanged, whereas the percentage of Thy-1 positive cells had decreased. Still significant numbers of such cells could be demonstrated in the IEL of nude mice. Altogether these results show that, at least, a significant part of the gamma delta receptor bearing IEL is independent of the thymus for their differentiation.

Animals↗
PubMed1989

Implantation of cultured thymic fragments in athymic nude rats: studies on tolerance towards donor haplotype.

We previously observed that nude rats after implantation of cultured thymic fragments (CTF) of allogeneic origin manifest in vitro alloreactivity to the donor haplotype, but not to host haplotype. We here extend preliminary data that this in vitro alloreactivity is not accompanied by in vivo rejection of skin transplant from donor CTF origin. This discrepancy between in vivo and in vitro alloreactivity may suggest the presence of peripheral in vivo suppressive mechanisms, which are not active in in vitro assay systems. After implantation of CTF from two different allogeneic strains, however, skin transplants of either one of the donor strains are rejected. We conclude that education of both types of alloreactivity has occurred in the respective CTF's. This latter observation indicates that the suppressive mechanisms hypothesized above, if existent at all, obviously are not sufficiently potent to suppress the alloreactivity which has been generated in a CTF which expresses MHC antigens irrelevant to the alloreaction inducing determinants. If the tolerance to donor CTF is not due to a peripheral tolerance/suppression, it might bear relation to events occurring during precursor T-cell processing in the grafted CTF. The state of chimaerism in the graft reported earlier may explain this tolerance.

Animals↗
PubMed1989

Defects in the thymic epithelial stroma of diabetes prone BB rats.

The thymus of diabetes prone BB rats (DP) was studied and compared with diabetes resistant (DR) BB rats and normal WAG rats. Thymuses were obtained from 4-5 week old animals, i.e. before the onset of disease. Analysis included specific immune histology using a panel of monoclonal antibodies directed against markers both on thymocytes and stromal cells. No striking differences were observed between the three groups with regard to the expression and distribution of the various T cell markers. There was however a marked difference for thymic class II MHC antigen expression between the various groups. Whereas WAG rats displayed a regular class II MHC pattern both in the cortex and the medulla, both DR and DP rats showed large areas in the cortex where there was no class II MHC staining. The lack of expression of class II MHC antigens in these 'holes' was associated with a complete absence of epithelial cells in that area. Also in the medulla of DP and DR thymuses 'holes' in the keratin-stroma were observed. The stromal aberrations in these auto-immune prone rats are discussed in the context of the deficient T cell system in these animals.

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