Nucleotide sequence of cattle FcGRIII: its identification in gammadelta T cells.
Explore the source record for details and available documents.
Amino Acid Sequence↗
Biomedical subjects
K I Gelder
Publications and source records attributed to K I Gelder.
Bovine gamma/delta TcR+ T lymphocytes are stimulated to proliferate by autologous Theileria annulata-infected cells in the presence of interleukin-2.
An in vitro model system has been developed in which freshly isolated resting WC1+ gamma/delta TcR+ T cells proliferate in response to cells transformed by the protozoan parasite Theileria annulata, providing a strategy in which the basis of activation of naive gamma/delta T cells can be investigated. Irradiated parasite-transformed cells stimulate the proliferation, but not cytolytic activity, of autologous peripheral blood mononuclear cells (PBMC) from non-immune animals. The proliferating cells are mainly WC1+ gamma/delta T cells. The majority of WC1+ gamma/delta T cells in freshly isolated PBMC express CD25 at a low level that increases when stimulated with T. annulata-infected cells. Purified WC1+ gamma/delta T cells fail to proliferate when cultured with irradiated T. annulata-infected cells and produce a small proliferative response to IL-2, but proliferate strongly to irradiated or lightly fixed Theileria-infected cells in combination with IL-2. The Theileria-infected cells express cytokine transcripts encoding IL-1 alpha, IL-1 beta, IL-6 and IL-10, but not IFN gamma, IL-2, IL-4 and IL-7. Purified WC1+ gamma/delta T cells stimulated with T. annulata-infected cells with or without IL-2 fail to produce IL-2 transcripts, but do produce those for TNF alpha. These experiments show that WC1+ gamma/delta T cells recognize a surface determinant on T. annulata-infected cells, that together with a second signal, which can be provided by exogenous IL-2, stimulates their proliferation.
Animals↗
Cloning and biologic activities of a bovine interferon-alpha isolated from the epithelium of a rotavirus-infected calf.
A cDNA encoding a distinct bovine (Bo) interferon (IFN) alpha, designated BoIFN-alpha E, was generated from gut epithelial cells isolated from a rotavirus-infected calf. The BoIFN-alpha E cDNA sequence shared a greater than 90% identity with the other BoIFN-alpha subtypes. The cDNA encoding BoIFN-alpha E has been expressed in insect cells using the baculovirus Autographa californica nuclear polyhedrosis virus (AcMNPV) as a vector. Insect cells infected with recombinant virus secreted a protein with a relative molecular mass of 19,500 into the culture medium not observed in cells infected with wild-type AcMNPV. Supernatants harvested from cultures of insect cells infected with the recombinant AcMNPV encoding IFN-alpha E inhibited the replication of Semliki Forest virus in a bovine cell line and typically showed 10(6) dilution units/ml of antiviral activity. However, differences were observed between the activities of recombinant BoIFN-alpha E and BoIFN-alpha 1 1 on the proliferation of WC1+ gamma/delta T cells. Purified ( > 99%) WC1+ gamma/delta T cells failed to proliferate to IFN-alpha 1 1 or concanavalin A and IFN-alpha E acted as a weak proliferative signal to these cells, demonstrating a functional difference between two closely related BoIFN-alpha subtypes.
Amino Acid Sequence↗
CD45RO expression on bovine T cells: relation to biological function.
The 180,000 MW isoform of CD45 (CD45RO) has been identified in cattle with a novel monoclonal antibody (mAb) (IL-A116). This has allowed a more precise analysis of T-cell function in relation to CD45 isoform expression. Within the CD4+ and CD8+ T-cell populations, CD45RO+ and CD45RO- subsets were evident. Most CD4+ and CD8+ T cells that expressed the CD45RO isoform did not express the 220,000 and 205,000 MW isoforms recognized by mAb CC76. In contrast, the WC1+, CD2-, CD4-, CD8-, gamma delta T-cell receptor (TCR)+ T cells in bovine peripheral blood mononuclear cells (PBMC) were all CD45RO+. Monocytes and granulocytes were CD45RO+ but B cells were CD45RO-. Sorting experiments with CD4+ T cells from an immunized calf demonstrated that proliferative responses to ovalbumin (OVA) were entirely within the CD45RO+ subset. Following stimulation with concanavalin A (Con A) the CD45RO- subset of CD4+ T cells produced transcripts for interleukin-2 (IL-2) but not IL-4 or interferon-gamma (IFN-gamma), while the CD45RO+ subset produced mRNA for IL-2, IL-4 and IFN-gamma. Biologically active IL-2 was present in supernatants from both CD45RO+ and CD45RO-, CD4+ T cells, and IFN-gamma protein was identified by ELISA in supernatants from the CD45RO+ subset, confirming the production of cytokines implied by polymerase chain reaction (PCR). In contrast, sorting experiments with CD8+ T cells from animals immune to the protozoan parasite Theileria parva revealed substantial numbers of cytotoxic T-lymphocyte precursors in both the CD45RO+ and CD45RO- subsets. Thus it appears that although all antigenically primed CD4+ T cells remain CD45RO+, and expression of this molecule consequently identifies memory cells within PBMC, antigenically primed CD8+ T cells down-regulate CD45RO expression after activation.
Animals↗
Cloning and expression of bovine and porcine interleukin-2 in baculovirus and analysis of species cross-reactivity.
The cDNAs encoding bovine and porcine interleukin-2 (IL-2) have been expressed using the baculovirus Autographa californica nuclear polyhedrosis virus as a vector in insect cells. Insect cells infected with recombinant viruses secreted bovine and porcine IL-2 into the culture medium, with biological activities for maintaining the proliferation of homologous cells. When the activities of these two IL-2 proteins and commercially available human IL-2 were tested on heterologous cells differences were found. Recombinant bovine (rb)IL-2 only supported the growth of bovine lymphocytes and was not active on human, mouse or porcine lymphocytes. Recombinant porcine (rp)IL-2 and recombinant human (rh)IL-2 supported the proliferation of human, bovine, porcine and murine cells. However, the proliferative response of human lymphocytes to rpIL-2 was only 50% of that seen with rhIL-2. Sequence differences at the predicted p55 and p75 contact binding sites may explain this.
Amino Acid Sequence↗