When injected with live P815 tumour cells, DBA/2 mice developed cytotoxic cells reactive to the tumour. In addition, T helper cells from tumour-bearing mice enhanced the iri vitro generation of cytotoxic cells from normal DBA/2 spleen cells. The helper cells had the following properties (1) expression of the Thy-1.2 antigen; (2) resistance to y-radiation; (3) specific enhancement of the cytotoxic response to P815; (4) detectability in P815-bearing mice at the peak of cytotoxic cell activity; (5) activity in the early phase of cytotoxic cell activation. In parallel to the development of helper cell activity, suppressor cells were generated which suppressed the cytotoxic response to P815. These suppressor cells were removed by pre-treating mice with low doses of cyclophosphamide. High doses of cyclophosphamide reduced the cytotoxic response to both P815 and C57B1/6 alloantigens. Cyclophosphamide treatment reduced the frequency of cytotoxic precursor cells directed against P815, and an antigen-reactive helper cell involved in interleukin 2 production. Both interleukin 2 and thymocytes from P815-primed mice, restored the cytotoxic response against P815, to normal levels. Twenty six percent of animals primed with tumour cells cleared a challenge dose of P815 faster than unprimed control mice. Of these, 88% survived longer than the control animals. Eighteen percent of the recipients of cells from tumour-primed mice, cleared a challenge dose of P815 faster than mice injected with normal cells. Of these 53% survived significantly longer than control groups given either normal cells or no cells at all. Cells from mice primed to PPD showed significantly enhanced proliferative responses to soluble and P815-bound PPD, when compared with unprimed animals. However, cells from only a few PPD-primed mice showed enhanced cytotoxicity against P815 tumour cells, and PPD-primed cells either did not alter, or suppressed, the cytotoxic response of normal DBA/2 spleen cells, when stimulated with PPD-coated P815. / Science, Faculty of / Microbiology and Immunology, Department of / Graduate

The Bar-Or laboratory recently reported that human B cells from normal subjects can produce either pro-inflammatory (TNF-alpha; LT) or regulatory (IL-10) effector cytokines depending on their context of activation. It was of interest to investigate the change in B cell cytokine profiles from normal subjects when activated in the context of a Th1 pro-inflammatory environment or a Th2 anti-inflammatory environment. It was found that the B cell regulatory network of effector cytokines from normal subjects is significantly modulated depending on the local cytokine milieu. In addition, it was of interest to study how MS patients' B cell cytokine network would respond in a Th1 pro-inflammatory and a Th2 anti-inflammatory context. It was found that MS patients' B cell cytokine network was dysregulated compared to B cell responses from normal subjects. The findings define a novel regulatory network involving human B cells from normal subjects and point to a newly discovered abnormality in MS patients' B cells.

Thesis (Ph. D.)--West Virginia University, 2005 / Title from document title page. Document formatted into pages; contains ix, 155 p. : ill. Vita. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 64-80).

A T helper cell clone, referred to as clone 9, was derived from an allogeneic mixed lymphocyte culture. Clone 9, as well as supernatant factor(s) derived from it, could help the cytotoxic T lymphocyte (CTL) responses of H-2 Db (Db) responder cells to alloantigens, or they could help the CTL responses of non- Db responder cells to Db alloantigens. Clone 9 cells or their factor(s) were active only when added during the first 24 hours of a five-day culture period. Clone 9 or its factor(s) could also synergize with interleukin-2 (IL-2)-containing medium in mounting cytotoxic responses to alloantigens. The helper activity in clone 9 supernatant was not due to IL-2 and it was specifically absorbed out by Db -spleen cells. The characterization of the Db -specific helper factor(ASHF) was facilitated by the isolation of a T hybridoma clone (clone 25), obtained from fusion of clone 9 cells with the T cell lymphoma, BW5147, and a B cell hybridoma that produced an IgM monoclonal antibody (clone 30 IgM) which bound ASHF. An additional monoclonal antibody (F23.1), which recognizes a determinant of the Vβ8 family of the T cell receptor, was also particularly useful for the characterization of ASHF. Analysis with these reagents showed that both clone 30 IgM and F23.1 immunoadsorbents could retain ASHF activity. Preabsorption of the ASHF with Db spleen cells prior to affinity purification over a clone 30 IgM column resulted in the absorption of Db-specific helper activity as well as the loss of a 50,000 molecular weight (MW) band on SDS-PAGE under reducing conditions. Furthermore, affinity purification of ASHF over the F23.1 immunoadsorbent, but not an irrelevant monoclonal antibody (mAb) column, also yielded a 50,000 MW molecule. Taken together, these findings suggest that the 50,000 MW molecule is a component of the ASHF and it is intimately related to the B chain of the T-cell receptor. The mode of action of clone 9 and its products in the induction bfCTL responses was also investigated. It was found that clone 9 and ASHF could help CTL responses by inducing IL-2 production in B6-stimulated cultures. In addition to ASHF, clone 9 cells also produced an additional factor(s) which participated in the induction of CTL responses. This additional factor(s) was referred to as IL-X. IL-X synergized with excess human recombinant IL-2 in the activation of CTL precursors (CTL-P) in the absence of antigenic stimulation. A model which involves the participation of ASHF, T helper cells, IL-2 and IL-X in the induction of CTL responses is proposed. / Science, Faculty of / Microbiology and Immunology, Department of / Graduate

B cells get help in the antibody response by presenting processed antigen to helper T cells. We asked whether the antigen presenting B cell must induce T helper functions before receiving help, or whether B cell activation is a direct consequence of T cell antigen recognition on the B cell surface. Although antigen-dependent increases in B cell c-myc expression occur as early as two hours after conjugation, the B cell response depends on induction of a contact-dependent helper function in the T cell, which is inhibitable by cyclosporin A. Induction but not delivery of contact help is blocked by anti-class II MHC antibody, indicating that the delivery of T cell help is not Ag dependent or MHC restricted. Also, contact with activated helper T cells induces a different pattern of immediate early gene expression from signals transduced through the B cell antigen receptor. Egr-1 is rapidly upregulated in response to mitogenic signals induced by receptor crosslinking on murine B lymphocytes, and its expression closely correlates with B cell proliferation in several models of B cell activation and tolerance. We compared egr-1 expression during B cell stimulation with Fab'2 and IgG anti-Ig, since it is known that Fab'2 anti-Ig is mitogenic while IgG is not, due to a dominant inhibitory effect of crosslinking the B cell FcγRII to membrane Ig. While mitogenic doses of Fab'2 anti-Ig induce large and rapid increases in egr-1 expression, intact anti-Ig results in only small increases in egr-1 mRNA, comparable to that seen with submitogenic concentrations of Fab'2 anti-Ig. However, when IL-4 is added as a comitogen to induce B cell proliferation with submitogenic concentrations of Fab'2 anti-Ig or IgG anti-Ig, no concomitant increases in egr-1 are observed. The regulation of egr-1 therefore, is similar to that of c-myc in this system, since neither correlates with IL-4 induced DNA synthesis.

No description available.

DNA immunization, inoculation with an antigen-expressing plasmid DNA, is a new method for generating an antigen-specific immune response. At the time these investigations began, very little was known about the immune response produced by DNA vaccines. Thus, the first aim of our studies was to perform a detailed examination of the antibody response generated by DNA immunization with an influenza hemagglutinin (HA)-expressing DNA in BALB/c mice. Using several different routes and methods of DNA immunization, we observed a number of findings. Although all three forms of DNA immunization elicited strong anti-HA antibody responses, i.m. and i.d. saline DNA immunization required approximately 100 times more DNA than a gene gun DNA immunization to raise an equivalent titer of anti-HA antibody. Indeed, as little as one inoculation and one boost by gene gun of 0.0004 μg of DNA produced a measurable antibody response in 50% of mice. Unexpectedly, we found the isotype of the antibody response differed among groups of mice immunized by different forms of DNA immunization. Intramuscular and i.d. saline DNA immunization produced predominantly an IgG2a anti-HA antibody response, whereas gene gun DNA immunization elicited mostly an IgG1 anti-HA antibody response. Considering that IgG2a and IgG1 antibody isotypes were known to correlate with Th1 and Th2 immune responses, respectively, we analyzed the type of immune responses produced by i.m., i.d., and gene gun DNA immunization. We found that i.m. and i.d. saline DNA immunization produced a Th1 predominant cellular immune response. In contrast, gene gun DNA immunization produced a Th2 cellular immune response. The differences in the type of immune responses were found to be due to the method of DNA immunization, and not due to the route of DNA inoculation. A gene gun DNA immunization of muscle produced the same IgG1, Th2 immune response as a gene gun DNA immunization of skin, while a saline DNA immunization of muscle and skin produced mostly an IgG2a, Th1 immune response. Each method of DNA immunization created good memory Th cell responses. The type of immune response created by an initial DNA immunization remained fixed even after multiple boosts with the identical method of DNA immunization, following a boost with the alternative method of DNA immunization, or after a viral challenge. The differentiation of naive Th cells into Th1 or Th2 cells depends on a variety of factors. We performed many experiments to elucidate which factors played a role in the generation of Th1 or Th2 immune responses following saline DNA immunization and gene gun DNA immunization. DNA dose response studies revealed the use of different doses of DNA between groups of saline DNA and gene gun DNA immunized mice did not account for the differentiation of distinct Th cell subsets. Cytokine production inducible by a number of factors inherently associated with either saline DNA or gene gun DNA immunization did not affect Th differentiation. For instance, contamination of plasmid DNA with lipopolysaccharide did not account for differences in the immune response. Immunostimulatory CpG sequences did not affect Th differentiation following DNA immunization, but they did enhance the IgG2a antibody response to coinoculated HA protein. Finally, cotransfection of IFNγ or IL-4 expressing plasmids with an HA-expressing plasmid by gene gun inoculation or as a saline DNA injection did not shift the type of immune response in a Th1 or Th2 direction, respectively. Thus, it appeared that increased cytokine stimulation was not responsible for selective Th subset differentiation. One factor related to the method of DNA immunization did seem to correlate with Th1 differentiation. Deposition of plasmid DNA extracellulary by saline DNA injections (as opposed to intracellular DNA delivery by gene gun) may have stimulated Th1 immune responses. Manipulating a gene gun DNA immunization to deliver DNA to the dermis (and thus extracellularly) shifted the immune response from that of a Th2 type to a mixed Th1/Th2 type. Furthermore, evidence was gathered demonstrating that pDNA can interact with cell surface molecules and that specific sequences in pDNA can act as a ligand and bind to molecules. Taken together, our data led us to propose a new model for Th1 differentiation following saline DNA immunization. We believe extracellular pDNA binds to an APC cell surface molecule which activates the cell. The activated APC preferentially stimulates naive Th cells to differentiate into Th1 cells. Finally, studies using a variety of mice differing in their genetic backgound and MHC genotype demonstrated the generality of our findings regarding i.m. saline DNA inoculations of an HA-expressing pDNA. Saline DNA immunization produced IgG2a, Th1-predominant immune responses independent of the genetic background and MHC genotype of the mice. In contrast, the type of immune response elicited by a gene gun DNA immunization was dependent on the MHC genotype of mice. Thus the type of immune response produced by gene gun DNA immunization probably depends on the specific antigen (and its effect on MHC-peptide/TcR interaction and signaling) and is less likely due to any inherent feature associated with the process of gene gun DNA delivery.

by Li Pok Wai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 94-114). / Abstracts in English and Chinese. / Acknowledgements --- p.I / Abbreviations --- p.II / Abstract --- p.V / 摘要 --- p.VIII / Publications --- p.XI / Table of contents --- p.XII / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Human Th lymphocytes and their immunopathogenic roles --- p.1 / Chapter 1.1.1 --- Characteristics of Th lymphocytes --- p.1 / Chapter 1.1.2 --- Migration and activation --- p.1 / Chapter 1.1.3 --- Th cell differentiation --- p.2 / Chapter 1.1.4 --- Pathological roles --- p.4 / Chapter 1.2 --- Cytokines as modulator in Th lymphocyte activation --- p.6 / Chapter 1.2.1 --- IL-18 --- p.6 / Chapter 1.2.2 --- IL-25 --- p.7 / Chapter 1.3 --- Surface marker expression in Th lymphocytes --- p.8 / Chapter 1.3.1 --- Adhesion molecules --- p.8 / Chapter 1.3.2 --- Cytokine and chemokine receptors --- p.9 / Chapter 1.3.3 --- Costimulatory molecules --- p.11 / Chapter 1.4 --- Cytokine and chemokine release from Th lymphocytes / Chapter 1.4.1 --- Thl cytokines --- p.13 / Chapter 1.4.2 --- Th2 cytokines --- p.14 / Chapter 1.4.3 --- Chemokines --- p.15 / Chapter 1.5 --- Intracellular signaling pathways in Th lymphocytes --- p.19 / Chapter 1.5.1 --- p38 MAPK pathway --- p.19 / Chapter 1.5.2 --- ERK pathway --- p.20 / Chapter 1.5.3 --- JNK pathway --- p.20 / Chapter 1.5.4 --- NF- k B pathway --- p.21 / Chapter 1.6 --- Pharmacological intervention of signaling pathways --- p.22 / Chapter 1.7 --- Aims and scope of the study --- p.24 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1 --- Materials --- p.26 / Chapter 2.1.1 --- Blood samples --- p.26 / Chapter 2.1.2 --- Media and reagents for cell culture --- p.26 / Chapter 2.1.3 --- Antibodies for costimulation of Th cells --- p.28 / Chapter 2.1.4 --- Recombinant human cytokines --- p.28 / Chapter 2.1.5 --- "Signaling pathway inhibitors: SB203580, PD98035, SP600125 and BAY117082" --- p.28 / Chapter 2.1.6 --- Monoclonal antibodies and reagents for immunofluorescent staining --- p.29 / Chapter 2.1.7 --- Reagents and buffers for the purification of human Th lymphocytes --- p.31 / Chapter 2.1.8 --- Reagents and buffers for protein array --- p.32 / Chapter 2.1.9 --- Reagents and buffers for Thl/2 cytokine and chemokine detection --- p.32 / Chapter 2.1.10 --- Reagents and buffers for protein extraction --- p.32 / Chapter 2.1.11 --- Reagents and buffers for SDS-polyacrylamide gel electrophoresis --- p.33 / Chapter 2.1.12 --- Reagents and buffers for Western blot analysis --- p.35 / Chapter 2.1.13 --- Reagents and buffers for non-radioactive electromobility shift assay (EMSA) --- p.37 / Chapter 2.1.14 --- Reagents and buffers for cell viability and proliferation assay --- p.39 / Chapter 2.1.15 --- Reagent kit for endotoxin level assay --- p.39 / Chapter 2.1.16 --- Other reagent kits --- p.40 / Chapter 2.2 --- Methods --- p.41 / Chapter 2.2.1 --- Purification of human Th lymphocytes and cell culture --- p.41 / Chapter 2.2.2 --- Measurement of total and allergen-specific IgE concentrations --- p.41 / Chapter 2.2.3 --- Immunophenotyping of cells by flow cytometry --- p.42 / Chapter 2.2.4 --- Protein array --- p.42 / Chapter 2.2.5 --- Quantitative analysis of cytokines and chemokines by flow cytometry --- p.43 / Chapter 2.2.6 --- Quantitative analysis of IFN-γ by ELISA --- p.43 / Chapter 2.2.7 --- SDS-PAGE --- p.44 / Chapter 2.2.8 --- Western blot analysis --- p.44 / Chapter 2.2.9 --- EMSA / gel shift assay --- p.45 / Chapter 2.2.10 --- MTT assay --- p.46 / Chapter 2.2.11 --- Cell proliferation assay --- p.46 / Chapter 2.2.12 --- Endotoxin level assay --- p.47 / Chapter 2.2.13 --- Statistical analysis --- p.47 / Chapter Chapter 3 --- Results / Chapter 3.1 --- Effects of IL-18 and IL-25 on the induction of Thl/2 cytokine and chemokine release from costimulated Th lymphocytes --- p.48 / Chapter 3.1.1 --- IL-18 and IL-25 could up-regulate the protein expression of cytokines and chemokines --- p.48 / Chapter 3.1.2 --- IL-18 but not IL-25 induced the release of IFN-γ and TNF-α --- p.48 / Chapter 3.1.3 --- "IL-18 and IL-25 induced the release of IL-5, IL-6 and IL-10" --- p.49 / Chapter 3.1.4 --- "IL-18 induced the release of IP-10, MIG, RANTES, MlP-lα and IL-8" --- p.49 / Chapter 3.1.5 --- "IL-25 induced the release of IP-10, MIG and RANTES" --- p.49 / Chapter 3.1.6 --- IL-18 and IL-25 did not enhance the proliferation of costimulated Th cells --- p.49 / Chapter 3.2 --- "Effects of IL-18 and IL-25 on the activation of p38 MAPK, ERK, JNK and NF- k B" --- p.58 / Chapter 3.2.1 --- "Costimulation with or without IL-18 and IL-25 could activate p38 MAPK, ERK and JNK" --- p.58 / Chapter 3.2.2 --- Costimulation with or without IL-18 and IL-25 could induce NF- k B activity --- p.58 / Chapter 3.3 --- Effects of inhibitors on the IL-18 and IL-25-induced release of Thl/2 cytokines and chemokines --- p.63 / Chapter 3.3.1 --- "Optimal dosage of SB203580, PD98035, SP600125 and BAY117082" --- p.63 / Chapter 3.3.2 --- "SB203580, PD98035 and BAY 117082 but not SP600125 suppressed the IL-18 and IL-25-induced release of Thl/2 cytokines" --- p.63 / Chapter 3.3.3 --- SP600125 suppressed the IL-18 and IL-25-induced release of chemokines --- p.64 / Chapter 3.4 --- Effects of inhibitors on the cell surface expression of IL-18 and IL-25 receptors --- p.72 / Chapter 3.4.1 --- "SB203580, PD98035, BAY 117082 but not SP600125 could suppress IL-18 receptor on costimulated Th cells" --- p.72 / Chapter 3.4.2 --- "SB203580, SP600125, PD98035 and BAY 117082 could not suppress IL-25 receptor on costimulated Th cells" --- p.72 / Chapter 3.5 --- Effects of costimulation on the expression of cell surface markers on Th lymphocytes --- p.75 / Chapter Chapter 4 --- Discussion / Chapter 4.1 --- Effects of IL-18 and IL-25 on the release of Th1/2 cytokines and chemokines --- p.80 / Chapter 4.2 --- "Regulation of Thl/2 cytokines and chemokines through intracellular p38 MAPK, ERK, JNKand NF-kB" --- p.83 / Chapter 4.3 --- Effects of costimulation on different surface markers in Th cells --- p.87 / Chapter 4.4 --- Concluding remarks and future perspectives --- p.90 / References --- p.94