scholarly journals Research Note: T-Cell Activity of White Leghorn Chickens Selected for High and Low Antibody Responses to Sheep Erythrocytes

1991 ◽  
Vol 70 (8) ◽  
pp. 1831-1834 ◽  
Author(s):  
T.R. SCOTT ◽  
E.A. DUNNINGTON ◽  
P.B. SIEGEL
Keyword(s):  
T Cell ◽  
Cell Activity ◽  
Antibody Responses ◽  
Research Note ◽  
White Leghorn ◽  
Sheep Erythrocytes

scholarly journals Antigen-specific suppressor T-cell activity in genetically restricted immune spleen cells.

1978 ◽  
Vol 148 (5) ◽  
pp. 1271-1281 ◽  
Author(s):  
C W Pierce ◽  
J A Kapp
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Activity ◽  
Antibody Responses ◽  
Spleen Cells ◽  
Suppressor T Cells ◽  
Specific Suppressor T Cells ◽  
Immune Spleen Cells

Virgin spleen cells develop comparable primary antibody responses in vitro to syngeneic or allogeneic macrophages (Mphi) bearing the terpolymer L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT), whereas immune spleen cells primed with syngeneic or allogeneic GAT-Mphi develop secondary responses preferentially when stimulated with GAT-Mphi syngeneic to the GAT-Mphi used for priming in vivo. These restrictions are mediated by products of the I-A subregion of the H-2 complex and are operative at the level of the GAT-Mphi-immune helper T-cell interactions. To investigate why these immune spleen cells fail to develop a significant antibody response to GAT-Mphi other than those used for in vivo immunization and determine the mechanism by which the restriction is maintained, spleen cells from virgin and syngeneic or allogeneic GAT-Mphi-primed mice were co-cultured in the presence of GAT-Mphi of various haplotypes. Antibody responses to GAT developed only in the presence of GAT-Mphi syngeneic to the Mphi used for in vivo priming; responses in cultures with GAT-Mphi allogeneic to the priming Mphi, whether these Mphi were syngeneic or allogeneic with respect to the responding spleen cells, were suppressed. The suppression was mediated by GAT-specific radiosensitive T cells. Thus, development of GAT-specific suppressor T cells appears to be a natural consequence of the immune response to GAT in responder as well as nonresponder mice. The implications of stimulation of genetically restricted immune helper T cells, and antigen-specific, but unrestricted, suppressor T cells after immunization with GAT-Mphi in vivo are discussed in the context of regulatory mechanisms in antibody responses.

scholarly journals In Vitro T Cell Activity in Two Chicken Lines Divergently Selected for Antibody Response to Sheep Erythrocytes

1994 ◽  
Vol 73 (2) ◽  
pp. 336-340 ◽  
Author(s):  
M.B. KREUKNIET ◽  
N. GIANOTTEN ◽  
M.B.G. NIEUWLAND ◽  
H.K. PARMENTIER
Keyword(s):  
T Cell ◽  
Antibody Response ◽  
Cell Activity ◽  
Sheep Erythrocytes

scholarly journals Regulatory functions of hapten-reactive helper and suppressor T lymphocytes. I. Detection and characterization of hapten-reactive suppressor T-cell activity in mice immunized with hapten-isologous protein conjugate

1977 ◽  
Vol 146 (1) ◽  
pp. 74-90 ◽  
Author(s):  
H Yamamoto ◽  
T Hamaoka ◽  
M Yoshizawa ◽  
M Kuroki ◽  
M Kitagawa
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cell Activity ◽  
Antibody Responses ◽  
Helper T Cells ◽  
Spleen Cells ◽  
Suppressor T Cells ◽  
Helper T Cell ◽  
Suppressor T Cell

Helper and suppressor T-cell activities were detected simultaneously in the spleen cells of mice immunized with para-azobenzoate (PAB)-mouse gammaglobulin (MGG). Dinitrophenyl (DNP)-specific B cells were raised by immunization with DNP-keyhole limpet hemocyanin (KLH) and used as the indicator B-cell population. The helper and suppressor T-cell activities were determined after adoptively transferring spleen cells from PAB-MGG- primed donors and DNP-KLH-primed donors into X-irradiated recipients. Stimulation of these recipients with DNP-MGG-PAB detected helper T-cell activity, which was measured in terms of increased anti-DNP antibody responses of DNP-KLH-primed cells over these responses in the presence of unprimed cells. On the other hand, when DNP-KLH-primed cells were stimulated with DNP-KLH-PAB in the presence of PAB-MGG-primed cells, anti-DNP antibody responses were substantially lower than in unprimed normal cells. This suppressor cell population was (a) hapten-reactive, (b) present in B-cell-depleted spleen cells, (c) Thy-1 positive, (d) detectable earlier than the helper T-cell activities after priming (e) more radiosensitive than helper cells, and (f) found in the spleen but not the lymph nodes in contrast to helper T cells. These data indicate that these suppressor T cells are distinct from the helper T cells. PAB-reactive T cells clearly suppressed the antibody response by inhibiting KLH-reactive helper T-cell functions. The hapten-reactive T-lymphocyte system described here should be useful for analyzing and manipulating the immune response and for studying regulatory interactions of helper and suppressor T cells in the induction of antibody responses.

scholarly journals Anti-tumor effects of RTX-240: an engineered red blood cell expressing 4-1BB ligand and interleukin-15

2021 ◽  
Author(s):  
Shannon L. McArdel ◽  
Anne-Sophie Dugast ◽  
Maegan E. Hoover ◽  
Arjun Bollampalli ◽  
Enping Hong ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Blood Cell ◽  
Nk Cells ◽  
Red Blood Cell ◽  
Safety Profile ◽  
Nk Cell ◽  
Cell Activity ◽  
In Vivo Studies

AbstractRecombinant agonists that activate co-stimulatory and cytokine receptors have shown limited clinical anticancer utility, potentially due to narrow therapeutic windows, the need for coordinated activation of co-stimulatory and cytokine pathways and the failure of agonistic antibodies to recapitulate signaling by endogenous ligands. RTX-240 is a genetically engineered red blood cell expressing 4-1BBL and IL-15/IL-15Rα fusion (IL-15TP). RTX-240 is designed to potently and simultaneously stimulate the 4-1BB and IL-15 pathways, thereby activating and expanding T cells and NK cells, while potentially offering an improved safety profile through restricted biodistribution. We assessed the ability of RTX-240 to expand and activate T cells and NK cells and evaluated the in vivo efficacy, pharmacodynamics and tolerability using murine models. Treatment of PBMCs with RTX-240 induced T cell and NK cell activation and proliferation. In vivo studies using mRBC-240, a mouse surrogate for RTX-240, revealed biodistribution predominantly to the red pulp of the spleen, leading to CD8 + T cell and NK cell expansion. mRBC-240 was efficacious in a B16-F10 melanoma model and led to increased NK cell infiltration into the lungs. mRBC-240 significantly inhibited CT26 tumor growth, in association with an increase in tumor-infiltrating proliferating and cytotoxic CD8 + T cells. mRBC-240 was tolerated and showed no evidence of hepatic injury at the highest feasible dose, compared with a 4-1BB agonistic antibody. RTX-240 promotes T cell and NK cell activity in preclinical models and shows efficacy and an improved safety profile. Based on these data, RTX-240 is now being evaluated in a clinical trial.

scholarly journals A biomimetic assay platform for the interrogation of antigen-dependent anti-tumor T-cell function

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jeremy To ◽  
Doug Quackenbush ◽  
Emily Rowell ◽  
Lilin Li ◽  
Connor Reed ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Function ◽  
Cell Activity ◽  
Cytotoxic T Cell ◽  
Dependent Manner ◽  
Cyclin Dependent Kinase ◽  
Histocompatibility Complex ◽  
T Cell Function ◽  
Cytolytic Granule ◽  
Screening Platform

AbstractOvercoming tumor-mediated immunosuppression and enhancing cytotoxic T-cell activity within the tumor microenvironment are two central goals of immuno-oncology (IO) drug discovery initiatives. However, exploratory assays involving immune components are often plagued by low-throughput and poor clinical relevance. Here we present an innovative ultra-high-content assay platform for interrogating T-cell-mediated killing of 3D multicellular tumor spheroids. Employing this assay platform in a chemical genomics screen of 1800 annotated compounds enabled identification of small molecule perturbagens capable of enhancing cytotoxic CD8+ T-cell activity in an antigen-dependent manner. Specifically, cyclin-dependent kinase (CDK) and bromodomain (BRD) protein inhibitors were shown to significantly augment anti-tumor T-cell function by increasing cytolytic granule and type II interferon secretion in T-cells in addition to upregulating major histocompatibility complex (MHC) expression and antigen presentation in tumor cells. The described biotechnology screening platform yields multi-parametric, clinically-relevant data and can be employed kinetically for the discovery of first-in-class IO therapeutic agents.

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