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Biomedical subjects

R A Good

Publications and source records attributed to R A Good.

At least 55 records · Page 3Linked to original sources
PubMed1998

Interleukin 12 deficiency associated with recurrent infections.

A 3-yr-old female patient exhibited interleukin 12 (IL-12) deficiency that was associated with recurrent episodes of pneumococcal pneumonia with sepsis and other infections in the absence of fevers. The patient's peripheral blood mononuclear cells (PBMCs) exhibited normal proliferative responses to antigens. Immune responses, including in vivo production of antibodies to diphtheria, tetanus, or pneumococcal antigens, were normal. Ig levels and B cell and T cell phenotypes were also normal. In contrast, IL-12 p70 heterodimer production was undetectable by using supernatants of the patient's stimulated PBMCs when compared with control cells treated similarly. Although present, interferon gamma (IFN-gamma) was reduced. The addition of recombinant IFN-gamma to control cells enhanced the production of IL-12 by up to sixfold. By contrast, IL-12 was undetectable in supernatants of the patient's cells in the presence of recombinant IFN-gamma. IL-12 p40 subunit mRNA by using the patient's PBMCs after stimulation with Staphylococcus aureus Cowan strain 1 or lipopolysaccharide was also undetectable by reverse transcription-PCR when compared with control cells. Production of IL-2, IL-6, tumor necrosis factor alpha, or IFN-gamma of the patient's PBMCs after appropriate stimulation was observed. This patient has either a defect in Staphylococcus aureus Cowan strain 1-lipopolysaccharide- or staphylococcal enterotoxin A-induced signaling pathways for the activation of IL-12 p40 gene expression, or an abnormality in the IL-12 p40 gene itself.

Adolescent↗
PubMed1998

Switch of CD4+ T cell differentiation from Th2 to Th1 by treatment with cathepsin B inhibitor in experimental leishmaniasis.

When activated, CD4+ T helper cells differentiate functionally into one of two subsets, Th1 or Th2. Before the Th differentiation, Ags must be processed into peptide epitopes and presented to CD4+ T cells in association with MHC class II molecules. However, the proteases responsible for this Ag processing have not been well defined. When BALB/c mice susceptible to infection with Leishmania major were treated with a specific inhibitor (CA074) of cathepsin B, a lysosomal cysteine protease that digests exogenous antigenic proteins, those mice acquired resistance against infection with L. major and showed the shift of immune responses from Th2 to Th1; that is, they produced specific IgG2a Ab and generated IFN-gamma in contrast to untreated and infected mice that produced IgG1 and IgE and generated IL-4. CA074 interfered with the digestion of L. major Ags with lysosomal enzymes in vivo as well as in vitro. However, this inhibitor did not show any direct influence on the growth of L. major and the functions of T cells stimulated with anti-CD3 Ab. These findings indicate that cathepsin B inhibitor could switch CD4+ T cell differentiation from Th2 to Th1, suggesting that the alteration in Ag processing modulates the polarity of Th differentiation.

Animals↗
PubMed1998

Intrathymic selection of NK1.1(+)alpha/beta T cell antigen receptor (TCR)+ cells in transgenic mice bearing TCR specific for chicken ovalbumin and restricted to I-Ad.

Generation and negative selection of NK1.1(+)alpha/beta T cell receptor (TCR)+ thymocytes were analyzed using TCR-transgenic (B10. D2 x DO10)F1 and (C57BL/6 x DO10)F1 mice and Rag-1(-/-)/DO10 mice, which had been established by breeding and backcrossing between Rag-1(-/-) and DO10 mice. Almost all T cells from these mice were shown to bear Valpha13/Vbeta8.2 that is specific for chicken ovalbumin (cOVA) and restricted to I-Ad. A normal proportion of the NK1.1(+) Valpha13/Vbeta8.2(+) thymocytes was generated in these mice. However, the actual cell number of both NK1.1(+) and NK1.1(-) thymocytes in I-Ad/d mice (positive selecting background) was larger than that in I-Ab/d mice (negative selecting background). Markedly low but significant proportions of NK1.1(+) Valpha13/Vbeta8.2(+) cells were detected in the spleens from I-Ad/d and I-Ab/d mice. It was shown that the splenic NK1.1(+) T cells of the I-Ab/d mice were anergized against stimulation through TCR. When (B10.D2 x DO10)F1 and (C57BL/6 x DO10)F1 mice were given cOVA, extensive or intermediate elimination of NK1.1(+)alpha/betaTCR+ thymocytes was induced in I-Ad/d or I-Ab/d mice, respectively. However, the clonal elimination was not as complete as that seen in the major NK1.1(-) thymocyte population. The present findings indicate that normal generation of NK1.1(+)alpha/betaTCR+ thymocytes occurs in the absence of Valpha14-Jalpha281 and that substantial negative selection operates on the NK1.1(+)alpha/betaTCR+ cells.

Animals↗
PubMed1998

A strategy for organ allografts without using immunosuppressants or irradiation.

A strategy to achieve regular and long lasting organ and tissue allografts without using immunosuppressants and/or irradiation has been established for mice. One hundred percent of skin allografts can be induced to survive >350 days after transplantation if spleen cells from the same donors are first injected into the portal vein of the recipients. The mechanisms underlying this long-term tolerance induction can be described as follows: (i) donor T cells from the spleen of the donor facilitate the acceptance of the allogeneic engraftment, (ii) donor-specific anergy is induced in the cytotoxic T-lymphocytes of the recipients, (iii) T helper type 2 cells become the dominant T cells in the recipients that are accepting the skin transplants, and (iv) a lasting chimerism (microchimerism) is established in these recipients. This strategy, perhaps with minor modifications, might permit one also to overcome major barriers to organ allografting in humans. If this were the case, it could represent production of long lasting immunologic tolerance without need for irradiation or cytotoxic chemo-preparative regimen and as such could greatly facilitate allotransplantation free of episodes of chronic or acute rejection or toxic and damaging preparatory regimens.

Adoptive Transfer↗
PubMed1998

Characterization of natural suppressor cells in human bone marrow.

Natural suppressor (NS) cells, which exert nonspecific suppressive activity in an unprimed manner, have been found in mouse, rabbit and monkey bone marrow (BM). In the present study, we characterize NS cells in human BM. NS activity was found in a fraction of low density (1.055-1.065 g/ml) BM cells that had been depleted of T cells, B cells, and monocytes. The NS activity was significantly decreased by the depletion of CD34+ or CD33+ cells but not CD56+ cells. The NS activity was indeed detected in isolated CD34+ cells and further enriched in CD34+CD33+ cells. Hematopoietic progenitor cells committed to the myeloid lineage were also enriched in the CD34+CD33+ cells, which significantly correlated to the NS activity. From these findings, it is strongly suggested that NS activity in human BM is exerted by the myeloid hematopoietic progenitors. Since cell-to-cell contact was not necessary for the action, NS cells seemed to secrete soluble mediator(s). Transforming growth factor-beta 1 and leukemia inhibitory factor were, however, not the candidates, based on experiments using neutralizing antibodies.

Antigens, CD↗
PubMed1998

An increase in basal glucocorticoid concentration with age induces suppressor macrophages with high-density Fc gamma RII/III.

Ageing is usually accompanied by a decline in immune and neuroendocrine functions. To elucidate the mechanisms underlying age-related immunosuppression, the functions and surface phenotypes of peritoneal cells in the monocyte/macrophage lineage from old mice were investigated. The role of glucocorticoids (GC) in the immunomodulation was also examined. Proliferative responses of spleen cells from control mice stimulated with concanavalin A (Con A) were significantly suppressed by adding peritoneal exudate cells from old mice. Flow cytometry analysis revealed that the proportion of MAC-1+ cells with a high density of type II or type III receptor for the Fc portion of IgG (Fc gamma RII/IIIbright cells) was increased markedly in the periotoneal exudate cells from old mice. The prominent suppressor activity for Con A responses of control spleen cells was found in the Fc gamma RII/IIIbright cells, whereas MAC-1+ cells with a low density of Fc gamma RII/III (Fc gamma RII/IIIdull cells) did not suppress the Con A responses. On the other hand, both the basal corticosterone concentrations in serum and the mRNA expression for GC receptor in peritoneal exudate cells increased significantly in old mice. Furthermore, the proportion of Fc gamma RII/IIIbright cells in peritoneal exudate cells from old mice was normalized on administration of the GC antagonist RU 38,486 (mifepristone). These results suggest that the increase in basal corticosterone concentrations in old mice induces the generation of Fc gamma RII/IIIbright suppressor cells, possibly leading to the immune-suppressive state.

Aging↗
PubMed1998

Desensitization to pancreatic enzyme intolerance in a child with cystic fibrosis.

OBJECTIVE: Pancreatic enzyme is essential in the treatment of cystic fibrosis (CF), but intolerance to it occasionally occurs. We encountered a child who was intolerant to multiple commercially available preparations of pancreatic enzymes and, hence, desensitization was attempted, with success. CASE PRESENTATION: A 33-month-old girl was diagnosed with CF at 6 months of age. Initially, she was started on Pancrease MT 16, which was subsequently discontinued because fecal fat studies were normal and she seemed to do well on Nutramigen and vitamin supplements. At 29 months of age, she developed diarrhea with bulky stools and weight loss. A fecal fat 72-hour study revealed a coefficient of absorption of 50%. She was treated with Pancrease MT 16, but had consistent vomiting 1 to 2 hours after administration of enzymes. The vomiting occurred on switching to different pancreatic enzymes preparations, ie, Creon 10, Viokase, and Pancrease MT 16. Vomiting occurred even with small doses of enzymes disguised in food. She had no history suggestive of gastroesophageal reflux, peptic ulcer, or pork allergy, and no vomiting on days when enzymes were not given. This was suggestive of type I hypersensitivity reaction. Pancreatic enzymes were discontinued, and she was given a low-fat, high-carbohydrate diet with satisfactory weight gain. METHODS: Double-blind, placebo-controlled titrated oral challenges with pancreatic enzymes resulted in definite vomiting within 1 to 1.5 hours after challenges with Viokase and Pancrease MT 16, but not with placebo. Rush oral desensitization with Viokase solution was attempted, starting with 5 mg, and the dose was doubled every 20 minutes, aiming to reach a cumulative dose of 700 mg. However, the child vomited when a cumulative dose of 315 mg was reached. Another trial of slower desensitization was done using Pancrease MT 16 (1 capsule: 16 000 U of lipase, 48 000 U of amylase, and 48 000 U of protease), starting with 1/4 capsule per day, with increments of 1/4 capsule every 3 days, until an entire capsule was reached by day 10, then increased by approximately 1/2 capsule every 4 days until reaching the therapeutic dose of 1 capsule with each meal by day 25. RESULTS: The patient tolerated this fairly well and has been on this treatment and regular diet for >1 year, without any adverse reaction. This illustrates a rare case of gastrointestinal adverse reaction to pancreatic enzymes that was treated successfully with desensitization. CONCLUSION: Pancreatic enzyme intolerance, although rare, would be a major problem in the management of patients with CF. Hence, desensitization would be essential and may be accomplished successfully using the protocol described in this report.

Child, Preschool↗
PubMed1998

Calorie restriction delays the crescentic glomerulonephritis of SCG/Kj mice.

Reduced dietary calories can delay the onset and diminish the severity of murine autoimmunities of numerous inbred and hybrid mutant strains. We sought to determine whether the precipitous, autoimmune, crescentic glomerulonephritis of recombinant inbred SCG/Kj mice could be abrogated similarly by calorie restriction. Weanling SCG/Kj mice develop hematuria and proteinuria, and 50% die as 16-week-old young adults. In this study, 113 4-week-old SCG/Kj mice were fed either ad libitum a milled chow (Group A, n = 50), or a semipurified diet (Group B, n = 29), or were fed a calorie-restricted semipurified diet (Group C, n = 34), so that mice of Group C consumed approximately 32% fewer calories, but similar amounts of essential dietary constituents as those of Group B. Calorie restriction of Group C provided modest (P = 0.05) or substantial survival advantage (P = 0.001) compared to the ad libitum feeding of Groups B or A, respectively. Progression to severe glomerular pathology was delayed among Group C mice, with more than a 5-week delay to heavy proteinuria (>100 mg/dl), a >4-week delay to hematuria, and a >5-week delay to median mortality, representing a 20% or 25% extension of median life span, compared to ad libitum-fed Group B and A mice, respectively. Mean glomerular histopathology scores were also lower in calorie-restricted mice compared to the ad libitum-fed cohorts (P = 0.001). Titers of anti-ss-DNA, ds-DNA, and ANCA autoantibodies developed in weanlings prior to the full imposition of calorie restriction and were not reduced significantly by calorie restriction.

Animals↗
PubMed1998

Prevention of crescentic glomerulonephritis in SCG/Kj mice by bone marrow transplantation.

Transplantation of MHC-compatible, T-cell-depleted, bone marrow cells has successfully treated autoimmunities, immunodeficiencies, malignancies, and developmental deficiencies of the hematopoietic system. Recombinant inbred SCG/Kj mice develop spontaneous crescentic glomerulonephritis, systemic vasculitis, and a lymphoproliferative disorder early in life. To determine whether the precipitous autoimmune disease of SCG/Kj mice could be treated by bone marrow transplantation, 30 SCG/Kj mice were engrafted with T-cell-depleted, bone marrow (TCDM) from allogeneic, MHC-compatible, autoimmune-resistant C3H/He donors, and 30 SCG/Kj mice served as controls and received TCDM from syngeneic, SCG/Kj donors. A significant survival advantage was evident from SCG/Kj mice engrafted with C3H/He TCDM (p < 0.005), and an 89% extension of median survival compared to recipients of SCG/Kj TCDM. Within 28 weeks post-transplantation, 62% of mice engrafted with SCG/Kj TCDM had died with clinical signs of fatal crescentic glomerulonephritis. This result compared with only 10% of mice engrafted with C3H/He TCDM. Mice engrafted with SCG/Kj TCDM developed significantly greater titers of autoantibodies to ss-DNA, ds-DNA, and myeloperoxidase (ANCA) (p < 0.001), had shorter latencies to the development of, and a greater incidence of proteinuria, hematuria, and peripheral lymphadenopathy, and a greater mean grade of glomerular lesion (p < 0.001), than mice engrafted with C3H/He TCDM. These findings indicate that the genetic defect of the SCG/Kj strain of mice resides within the hematopoietic stem cells and provokes the speculation that bone marrow transplantation might be a useful means of treating progressive crescentic glomerulonephritis in humans.

Animals↗
PubMed1998

Osteoblasts promote engraftment of allogeneic hematopoietic stem cells.

Hematopoietic progenitor cells (low density, lineage negative [Lin-], depleted of CD4+, CD8+, B220+, Gr-1+, Mac-1+, CD71+, and Thy1.2+ cells) can engraft lethally irradiated mice when transplanted within, but not across the major histocompatibility (MHC) antigen barrier. We hypothesized that our progenitor cell preparation required "supportive" cells/factors for successful engraftment. Our initial candidate supportive cells, dendritic cells, failed to facilitate engraftment of stem cells across fully allogeneic MHC barriers. Because interaction of stem cells with bone marrow (BM) stromal microenvironment is required for development, maturation, and differentiation of hematopoietic stem cells, and because bone transplants have been found to facilitate BM transplantation (BMT) in some strain combinations, we tested bone progenitor cells, osteoblasts, as facilitators of allogeneic stem cell engraftment. Osteoblasts, purified from donor murine long bones, were cotransplanted with marrow stem cells into fully allogeneic mouse strains. The transplanted mice demonstrated excellent long-term survival, were free of disease, and were entirely engrafted with cells of donor origin. Histologic sections of thymuses and spleens showed full reconstitution of lymphohematopoietic elements. Surprisingly, in contrast to fully allogeneic chimeras reconstituted by allogeneic T lymphocyte-depleted BM, our stem cell chimeras were found to produce an impressive primary antibody response to the cellular antigen, sheep red blood cells. Thus, bone progenitor cells or osteoblasts may represent an essential component of the stromal cell population and facilitate engraftment of marrow stem cells in an allogeneic environment.

Alkaline Phosphatase↗
PubMed1997

Purified hematopoietic stem cells without facilitating cells can repopulate fully allogeneic recipients across entire major histocompatibility complex transplantation barrier in mice.

We report herein the successful long term engraftment of highly purified hematopoietic stem cells (HSCs) without any facilitating cells in fully allogeneic recipient mice across the entire major histocompatibility complex (MHC) transplantation barrier. This finding challenges the assumption that highly purified marrow HSCs alone cannot produce long-lived allogeneic bone marrow chimeras across the MHC barrier. In the present experiments, 1 x 10(5) HSCs from 5-fluorouracil (5-FU)-treated donors, without any facilitating cells, have been found to repopulate lethally irradiated fully allogeneic recipients. Low density, lineage-negative (CD4-, CD8-, B220-, Mac-1-, Gr-1-), CD71-negative, class I highly positive, FACS-sorted cells from 5-FU-treated C57BL/6 (B6) donor mice were transplanted into lethally irradiated BALB/c recipients. (BALB/c --> BALB/c) --> BALB/c T cell-depleted marrow cells used as compromised cells were also transplanted into the recipients to permit experiments to be pursued over a long period of time. Cells of donor origin in all recognized lineages of hematopoietic cells developed in these allogeneic chimeras. One thousand HSCs were sufficient to repopulate hemiallogeneic recipients, but 1 x 10(4) HSCs alone from 5-FU-treated donors failed to repopulate the fully allogeneic recipients. Transplantation of primary marrow stromal cells or bones of the donor strain into recipient, together with 1 x 10(4) HSCs, also failed to reconstitute fully allogeneic recipients. Suppression of resistance of recipients by thymectomy or injections of granulocyte colony-stimulating factor before stem cell transplantation enhanced the engraftment of allogeneic HSCs. Our experiments show that reconstitution of all lymphohematopoietic lineages across the entire MHC transplantation barriers may be achieved by transplanting allogeneic HSCs alone, without any facilitating cells, as long as a sufficient number of HSCs is transplanted.

Animals↗
PubMed1997

Interaction of pigeon cytochrome c-(43-58) peptide analogs with either T cell antigen receptor or I-Ab molecule.

We determined that a pigeon cytochrome c-derived peptide, p43-58, possesses two anchor residues, 46 and 54, for binding with the I-Ab molecule that are compatible to the position 1 (P1) and position 9 (P9) of the core region in the major histocompatibility complex (MHC) class II binding peptides, respectively. In the present study to analyze each binding site between P1 and P9 of p43-58 to either I-Ab or T cell antigen receptor (TCR), we investigated T cell responses to a series of peptides (P2K, P3K, P4K, P5K, P6K, P7K, and P8E) that sequentially substituted charged amino acid residues for the residues at P2 to P8 of p43-58. T cells from C57BL/10 (I-Ab) mice immunized with P4K or P6K did not mount appreciable proliferative responses to the immunogens, but those primed with other peptides (P2K, P3K, P5K, P7K, and P8E) showed substantial responses in an immunogen-specific manner. It was demonstrated by binding studies that P1 and P9 functioned as main anchors and P4 and P6 functioned as secondary anchors to I-Ab. Analyses of Vbeta usage of T cell lines specific for these analogs suggested that P8 interacts with the complementarity-determining region 1 (CDR1)/CDR2 of the TCR beta chain. Furthermore, sequencing of the TCR on T cell hybridomas specific for these analogs indicated that P5 interacts with the CDR3 of the TCR beta chain. The present findings are consistent with the three-dimensional structure of the trimolecular complex that has been reported for TCR/peptide/MHC class I molecules.

Amino Acid Sequence↗
PubMed1997

Prevention of development of autoimmune disease in BXSB mice by mixed bone marrow transplantation.

Transplantations of fully allogeneic, autoimmune-resistant T-cell-depleted marrow (TCDM) plus syngeneic, autoimmune-prone TCDM into lethally irradiated BXSB mice were carried out to investigate the ability of the mixed bone marrow transplantation (BMT) to prevent development of autoimmune disease and, at the same time, to reconstitute fully the immunity functions of heavily irradiated BXSB recipients. Male BXSB mice were engrafted with mixed TCDM from both allogeneic, autoimmune-resistant BALB/c mice and syngeneic, autoimmune-prone BXSB mice. BMT with mixed TCDM from both resistant and susceptible strains of mice (mixed BMT) prolonged the median life span and inhibited development of glomerulonephritis in BXSB mice. BMT with mixed TCDM also prevented the formation of anti-DNA antibodies that is typically observed in male mice of this strain. Moreover, mixed BMT reconstituted primary antibody production in BXSB recipients, so that no annoying immunodeficiencies that are regularly observed in fully allogeneic chimeras were present in the recipient of the mixed TCDM. These findings indicate that transplanting allogeneic, autoimmune-resistant TCDM plus syngeneic, autoimmune-prone TCDM into lethally irradiated BXSB mice prevents development of autoimmune disease in this strain of mice. In addition, this dual BMT reconstitutes the immunity functions and avoids the immunodeficiencies that occur regularly in fully allogeneic chimeras after total-body irradiation.

Animals↗
PubMed1997

Heat shock protein 65 induced by gammadelta T cells prevents apoptosis of macrophages and contributes to host defense in mice infected with Toxoplasma gondii.

We previously reported that gammadelta T cells mediate the expression of endogenous heat shock protein 65 (HSP65) in macrophages of mice with acquired resistance against infection with Toxoplasma gondii. We show here that HSP65 contributes to protective immunity by preventing apoptosis of infected macrophages. Macrophages of BALB/c mice, which readily acquired resistance to T. gondii infection with the low virulence Beverley strain, strongly expressed HSP65, and only a few of these macrophages underwent apoptosis. On the other hand, the BALB/c mice were susceptible to the infection with the high virulence RH strain of T. gondii; their macrophages did not express HSP65 and did undergo apoptosis. Mice depleted of gammadelta T cells using a mAb specific for TCR-gammadelta became highly susceptible to infection even with the Beverley strain. In these mice, HSP65 expression was markedly suppressed, and their infected macrophages died via apoptosis. Apoptosis was induced in cultured macrophages or macrophage cell lines after infection in vitro with the RH strain, whereas apoptosis was prevented when HSP65 was induced in these cells, before infection, by activation with IFN-gamma and TNF-alpha. However, apoptosis associated with infection by T. gondii RH strain was not prevented when HSP65 synthesis was inhibited by introducing an antisense oligonucleotide for this protein into the cells before activation with IFN-gamma plus TNF-alpha. Thus, HSP65 appears to contribute to immunity by preventing the apoptosis of infected macrophages, and the high virulence Toxoplasma appears to have mechanisms that allow these organisms to evade the host defense system by interfering with HSP65 expression.

Animals↗
PubMed1997

Prolactin, epidermal growth factor or transforming growth factor-alpha activate a mammary cell-specific enhancer in mouse mammary tumor virus-long terminal repeat.

Mammary specific expression of elevated levels of mouse mammary tumor virus (MMTV) contributes to mammary carcinogenesis. Mechanisms which regulate provirus expression have not been completely defined. Using a MMTV-long repeat terminal (MMTV-LRT) directed chloramphenicol-acetyltransferase (CAT) reporter gene system and a human breast cancer cell line T47D, we demonstrate that prolactin (PRL), epidermal growth factor (EGF), or transforming growth factor-alpha (TGF-alpha) act on a mammary cell-specific enhancer at the extreme 5' end of the MMTV-LTR involving sequences -1094 through -858. PRL and either EGF or TGF-alpha exert concerted roles in this activation of these sequences. In contrast, using a plasmid construct lacking this mammary cell-specific enhancer, EGF or TGF-alpha, but not PRL, act synergistically with progesterone to induce CAT activity, indicating that the action of PRL on regulatory elements of the MMTV-LTR is restricted to this mammary cell-specific enhancer involving sequences -1094 through -858. A mobility shift assay was used to demonstrate that PRL, EGF or TGF-alpha induce nuclear factors (MP4, MAF, and MGF) which bind directly to this mammary cell-specific enhancer element.

Binding Sites↗