Biomedical subjects

S R Carding

Publications and source records attributed to S R Carding.

64 records · Page 4Linked to original sources

PubMed1989

MHC control of CD4+ T cell subset activation.

The present results demonstrate that CD4+ T cells activated in the primary in vivo response to antigen produce distinct patterns of cytokines depending upon the MHC class II haplotype of the responding mice. I-As mice were found to selectively activate IL-2/IFN-gamma-producing CD4+ T cells, whereas I-Ab mice exhibited selective activation of IL-4-producing CD4+ T cells in response to collagen IV. The effector response phenotype was found to correlate with the cytokine phenotype of CD4+ T cells activated in vivo; IL-2/IFN-gamma-producing cells giving rise to proliferative (cell-mediated) responses, IL-4-producing cells leading to secondary IgG (humoral) responses. Together the data support the notion that the outcome of a given immune response (e.g., protection vs. onset, tolerance vs. autoimmunity) may be determined in part by the type of CD4+ T cells initially activated by antigen. Moreover, the present experiments demonstrate for the first time that polymorphism in class II MHC can determine such selective activation of different cytokine-producing CD4+ T cell phenotypes.

Animals↗

PubMed1989

Differential activation of cytokine genes in normal CD4-bearing T cells is stimulus dependent.

Studies of cloned CD4+ T cell lines have shown that they can be separated into two distinct subsets with distinctions in their functional capabilities and by the differential release of either interleukin 2 (IL 2) (TH1/inflammatory type) or IL 4 (TH2/helper type) upon activation. To establish if in vivo-derived CD4+ T cells can exhibit distinct subsets we have investigated whether normal CD4+ T cells demonstrate differential expression of IL 2 and IL 4 mRNA, and secretion of IL 2 and IL 4 after primary stimulation in vitro. Utilizing the technique of in situ hybridization IL 2 and IL 4 gene expression in individual CD4+ T cells was readily detectable after concanavalin A (Con A) phytohemagglutinin (PHA) or pokeweed mitogen (PWM)-mediated activation. The frequencies of activated T cells producing IL 2 and IL 4 mRNA after Con A or PHA activation were approximately equivalent (30-40% of cells); however, after PWM activation the number of CD4+ T cells expressing IL 4 mRNA (78%) was more than twofold greater than the number of cells producing IL 2 mRNA (30%). Maximal levels of IL 2 gene expression occurred 24 h after mitogen activation whereas the highest levels of IL 4 mRNA were not detected until 48 h after mitogen activation. Similar distinctions in the kinetics of IL 2 and IL 4 secretion after mitogen activation were also found demonstrating good concordance in the observed expression of IL 2 and IL 4 mRNA and the levels of secreted lymphokines detected by bioassay. Most importantly, we have shown by in situ hybridization analysis that the majority of individual CD4+ T cells produce only IL 2 or IL 4 mRNA, and not both, after primary activation in vitro. By contrast, most CD4+ T cells activated in the presence of PMA and ionophore express both IL 2 and IL 4 mRNA. Our studies demonstrate that in normal, non-clonal populations of CD4+ T cells, the production of IL 2 and IL 4 is independently regulated in the majority of cells and appears to be stimulus dependent.

Animals↗

PubMed1989

In vivo administration of interleukin 1 elicits increased Ia antigen expression on B cells through the induction of interleukin 4.

The effects of the in vivo administration of interleukin 1 (IL 1) on lymphocytes from lymph node and spleen were analyzed. Mice received five daily subcutaneous (s.c.) injections of various doses of human recombinant IL 1 beta. Either 1 or 7 days after IL 1 treatment, spleens, popliteal and inguinal lymph nodes were collected. Lymphadenosis and splenomegaly were observed in the IL 1-treated animals. Lymph nodes from IL 1-treated mice contained a higher percentage of B cells than controls, and B cells from IL 1-treated mice expressed dramatically increased levels of Ia antigen. Lymphadenosis and splenomegaly, as well as the changes in subset distributions and Ia expression were transient. Concomitant treatment of mice with IL 1 and anti-IL 4 monoclonal antibody suppressed IL 1 effects on B cell Ia expression, but not on the B/T cell ratio. In situ hybridization analyses revealed that IL 1 treatment induced the expression of mRNA for IL 4, interferon-gamma, and IL 2 in lymph node and spleen cells. The distribution of cells expressing the various cytokine mRNA was markedly different between the spleens and lymph nodes.

Animals↗

PubMed1989

Diversity in T-cell receptor gamma gene usage in intestinal epithelium.

The intraepithelial cells of the murine small intestine include a significant number of CD3+ T cells that use T-cell receptor gamma genes rather than T-cell receptor beta genes. As with other sites of T-cell receptor gamma expression, combinatorial diversity is limited, but there is junctional diversity, and this, together with the specific variable region gamma gene segments used, distinguishes gamma gene expression in the gut epithelium from that in cells derived from the dermal epithelium. The restriction of productive gamma gene expression largely to one V-J-C (V, variable; J, joining; C, constant) gene combination may result from nonproductive joining of other V-J combinations and from productively rearranged genes rendered nonfunctional by incorrect splicing.

Animals↗

PubMed1989

Developmental control of lymphokine gene expression in fetal thymocytes during T-cell ontogeny.

We have used the technique of in situ hybridization to investigate the expression of lymphokine genes by immature thymocytes during intrathymic development. In 13-day fetal thymocytes a population of cells constitutively produces low levels of interleukin 2 (IL-2) and interleukin 4 (IL-4) mRNAs. A second phase of lymphokine gene expression occurs in the majority of 15-day thymocytes, and a population of cells constitutively produces both IL-2 and IL-4 mRNAs. Thymocytes at 14 days of gestation and after 16 days up until birth do not express detectable lymphokine mRNA. By contrast, the population of IL-2 receptor mRNA-producing thymocytes increases progressively up to 15 days of gestation, and expression thereafter decreases up to birth. In addition, thymocytes expressing interferon gamma mRNA were not present until just prior to birth. Our findings indicate developmental control of lymphokine and lymphokine receptor gene expression in fetal thymocytes during ontogeny.

Animals↗

PubMed1988

IL-4 (B cell stimulatory factor 1) exhibits thymocyte growth factor activity in the presence of IL-2.

The proliferative activity of thymocytes cultured with IL-2 and submitogenic concentrations of PHA is increased by 3- to 10-fold in the presence of IL-4. In contrast, IL-4 alone is unable to induce proliferative activity in thymocyte cultures and its synergistic activity is only apparent to concentrations of IL-2 above 1 U/ml. The costimulatory activity of IL-4 is abrogated by the monoclonal anti-IL-4 antibody 11B11. Furthermore, potentiation of the IL-2-mediated thymocyte proliferation is not seen with IL-1, IL-3, IFN-gamma, and granulocyte-macrophage CSF. Thymocytes are at least as responsive to IL-4 as B cells and the IL-4 costimulatory activity in fractionated thymocytes appears to be restricted mainly to the Lyt-2+/L3T4- population. In contrast, purified resting mature T cells do not respond to IL-4 plus IL-2, although they did proliferate in response to IL-4 in combination with PMA. These findings indicate that thymocytes and mature T cells are responsive to the costimulatory activity of IL-4 under quite different conditions, and that IL-4 may play an important role in thymocyte maturation in the thymus.

Animals↗

PubMed1985

Multiple proteins related to the soluble galactose-binding animal lectin revealed by a monoclonal anti-lectin antibody.

A monoclonal antibody (NIBy 142-36/8) raised against the soluble galactose-binding lectin of bovine heart muscle has been tested by solid-phase vinyl-plate radiobinding and nitrocellulose immunoblotting with homogenates of various bovine tissues, and the muscle tissues of pig, rabbit, chicken and rat. Muscle lectins of chicken, rabbit and rat differed from those of man and pig in their lack of reactivity with the 36/8 antibody. There was a good correlation of haemagglutinating activities and immunoreactivities of the bovine tissue homogenates, suggesting that the soluble galactose-binding protein is a major haemagglutinin in various tissues. Immunoblotting experiments revealed an array of antigenically active components in the homogenates in addition to the 13 and 26kDa proteins that were previously detected in preparations of purified lectin. These were in the range 36kDa to more than 200kDa, and a different spectrum of immunoreactive components was found in various cell types. Galactose-binding activity was demonstrable in 13, 26 and 36kDa components in certain bovine tissues, suggesting that the immunoreactive components of higher Mr may be inactive precursor forms of the lectin.

Animals↗

PubMed1985

Transformation and growth related changes in levels of nuclear and cytoplasmic proteins antigenically related to mammalian beta-galactoside-binding lectin.

Immunofluorescence and immunoblotting experiments, using a monoclonal antibody to the 13 kDa mammalian beta-galactoside-binding lectin have shown that human lymphocytes contain nuclear and cytoplasmic proteins of apparent molecular masses of 130, 80, 65 and 13 kDa that are antigenically related to the lectin and whose levels and patterns of expression change in association with transformation, or after stimulation with mitogens. These observations, together with the finding that the myeloid cell line K562 is also rich in the 130 kDa component, whereas the mature granulocytes of normal donors and of patients with chronic myeloid leukaemia are lacking in all of the immunoreactive forms, raise the possibility that this family of lectin-related proteins may be components of growth regulatory systems that are variously elicited in the transformed and stimulated cells.

Antibodies, Monoclonal↗

PubMed1984

Production and characterization of monoclonal antibodies to beta-galactoside-binding lectin of bovine heart muscle. Direct evidence that haemagglutinating activity is associated with a 13kDa protein.

With the aim of obtaining monospecific antibodies against the beta-galactoside-binding lectin of bovine heart muscle, spleen cells from Lou rats immunized with lectin were fused with the rat myeloma line Y3.Ag1.2.3. Two immunoglobulin M (IgM)-producing clones, designated NIBy 142-36/8 and NIBy 143-9/5, derived from separate fusions, were used to generate ascites containing high-titre binding activity against the 13kDa component in preparations of lectin. Direct evidence that haemagglutinating activity is associated with the 13kDa protein was obtained by the specific elution of 13kDa polypeptides with haemagglutinating activity from an immobilized antibody adsorbent. Solid-phase radiobinding assays and immunoblotting of isolated lectins and/or muscle homogenates confirmed the earlier indications with conventional antisera that the beta-galactoside-binding lectins of bovine, human and monkey muscle tissue are antigenically related.

Animals↗

PubMedDate not supplied

Cytokine profiles of bronchoalveolar lavage cells from mice with influenza pneumonia: consequences of CD4+ and CD8+ T cell depletion.

Cytokine production and mRNA profiles have been analyzed at the single cell level for bronchoalveolar lavage (BAL) populations from mice infected with an influenza A virus in the presence or absence of the CD4+ and CD8+ T cell subsets. Phagocytes were identified by their capacity to engulf latex particles, but the cellular elements of this inflammatory process were otherwise not characterized. BAL preparations from undepleted mice contained numerous IL-2, IL-4 and IFN-gamma-producing cells, with many fewer secreting TNF or IL-10. The frequency of mRNA+ cells detected by in situ hybridization was, in general, much higher than that for protein-secreting cells determined by ELISPOT analysis. In addition to IL-2, IL-4, and IFN-gamma, large numbers of cells were found to contain IL-10 and TNF-beta transcripts. Depletion of CD4+ and CD8+ cells caused significant reduction in the frequency of IL-2 and IL-4-producing cells, but even simultaneous elimination of both T cell subsets failed to totally remove all cells producing these cytokines. Similarly, a residual population of IFN-gamma-producing cells remained after depletion of the CD4+ and CD8+ subsets. Likely sources of these cytokines (apart from NK cells) are the CD4-8- alpha beta and gamma delta T cells found previously in BAL populations from doubly-depleted mice infected with this virus. Somewhat surprisingly, mRNA for IFN-gamma, IL-5, and TNF beta was prevalent in cells that had engulfed latex particles, though mRNA for IL-2 and IL-4 was never detected in macrophages.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗