scholarly journals Cell-mediated lympholysis to H-2-matched target cells modified with a series of nitrophenyl compounds.

1976 ◽  
Vol 144 (4) ◽  
pp. 1134-1140 ◽  
Author(s):  
T G Rehn ◽  
J K Inman ◽  
G M Shearer

The specificity of C57BL/10 cytotoxic effector cells generated by in vitro sensitization with autologous spleen cells modified with a series of related nitrophenyl compounds was investigated. The failure of trinitrophenyl (TNP)-sensitized effector cells to lyse TNP-beta-alanylglycylglycyl(AGG)-modified target cells is presented as evidence contradicting the intimacy or dual receptor model or T-cell recognition in its simplest form. Data are also shown indicating that sensitization with N-(3-nitro-4-hydroxy-5-iodophenylacetyl)-AGG-modified stimulating cells generates noncross-reacting clones of cytotoxic effector cells.

1978 ◽  
Vol 147 (6) ◽  
pp. 1551-1567 ◽  
Author(s):  
I C MacLennan ◽  
P Golstein

The requirement for D-glucose in T-cell-mediated cytolysis was studied using mouse spleen cells sensitized against alloantigens in vitro. Glucose was required for cytolysis: (a) cytolysis proceeded in a simple buffered salt solution containing Ca++ and Mg++ (low phosphate-buffered saline, LPBS) in the presence but not in the absence of added glucose; (b) 2-deoxy-D-glucose blocked cytolysis. The block by this agent was overcome by excess glucose added as late as 40 min after the inhibitor. This block was not due to inhibition of NADP reduction, since 2-deoxy-D-glucose failed to interfere with the rate of CO2 production by the pentose cycle which we found to be of significant activity in sensitized spleen cells; (c) dialyzed fetal bovine serum (DFBS) in LPBS supported cytolysis in the absence of added glucose. However, 2-deoxy-D-glucose was also inhibitory under these conditions, suggesting that carbohydrate was required here as well. Further results supported the conclusion that DFBS was not acting as a direct source of the required carbohydrate. The relationship between cytolysis, glucose requirement, and provision of energy was studied. As little as 0.1 mM D-glucose in LPBS supported cytolysis. At this glucose concentration, there was no measurable accumulation of lactate in sensitized spleen cells, but Krebs cycle activity was detectable. In 3 mM glucose or above, the range covered by standard tissue culture media, anaerobic glycolysis became a major source of energy in sensitized spleen cells. Consequently, it appears that in standard tissue culture medium, effector cells can generate sufficient energy for cytolysis either by aerobic or anaerobic metabolism. However, the addition of an energy source alone in the absence of glucose was insufficient to support cytolysis in LPBS. Pyruvate in LPBS did not support cytolysis but was shown to be a good substrate for aerobic metabolism in sensitized spleen cells. Glycogenic amino acids and glycerol also failed to support cytolysis. The stage of cytolysis at which glucose is required was investigated. Glucose was necessary for the calcium-dependent lethal hit phase, but not for the cytochalasin A-blockable recognition stage, nor for 51Cr release from injured target cells. Models for the lethal hit process are discussed, which are compatible with the observed requirement for certain hexoses unrelated to their capacity to serve as sources of energy.


1980 ◽  
Vol 152 (2) ◽  
pp. 405-418 ◽  
Author(s):  
R B Levy ◽  
P E Gilheany ◽  
G M Shearer

Murine spleen cells were sensitized in vitro to H-2 disparate allogeneic spleen cells and assayed on syngeneic target cells conjugated with the trinitrophenyl (TNP)-self or the fluorescein isothiocyanate (FITC)-self haptens, or on syngeneic target cells expressing the male H-Y antigen (H-Y self). The results indicated that allo-induced cytotoxic T lymphocytes (CTL) contained effectors that lysed both hapten-self but not H-Y self targets. Furthermore, it was demonstrated that separate populations of those allogeneic CTL were responsible for the lysis of TNP-self and FITC-self targets. This study also showed that cytotoxic effectors generated against the H-Y antigen with lytic activity equal to or greater than that of an allogeneically induced CTL response were unable to lyse hapten-self targets. These findings provide the first evidence that H-2 alloantigens may be unique in their ability to induce effectors that lyse hapten-conjugated autologous targets. These observations are discussed with respect to the self and foreign antigenic determinants involved in allogeneic and self-restricted CTL models.


1975 ◽  
Vol 142 (4) ◽  
pp. 914-927 ◽  
Author(s):  
A M Schmitt-Verhulst ◽  
G M Shearer

Murine thymus-derived lymphocytes can be sensitized in vitro to trinitrophenyl (TNP)-modified autologous spleen cells (1, 2). Cytotoxic effector cells were generated which were specific for TNP-modified target cells expressing the same H-2K and H-2D serological regions as the modified stimulator cells (3, 7). Spleen cells from two C57BL/10 congenic strains of mice sharing common I-C, S, and D regions, but differing at K, I-A, and I-B regions, generated different levels of lytic responses to the shared modified H-2Dd products upon sensitization with auto logous TNP-modified cells. Lymphocytes from an F1 between responder and nonresponder strain generated a level of cytolysis toward the H-2Dd modified specificity which was of the same order of magnitude as that obtained with the high responder, irrespective of whether F 1 or either parental strain of modified stimulator cell was used. These results suggest that the modification of H-2Dd products resulted in formation of new antigenic determinants in both parental strains. However, the difference observed in responsiveness appeared to be due to a gene or genes mapping in the K, I-A, or I-B region which influenced the ability of the responding lymphocytes to react to these modified H-2Dd products. Responsiveness was expressed as a dominant trait in the F1.


1976 ◽  
Vol 144 (4) ◽  
pp. 996-1008 ◽  
Author(s):  
J R Neefe ◽  
D H Sachs

Monolayers formed of normal mouse spleen cells attached to polystyrene coated with poly-L-lysine were tested for their ability to bind specifically antigen-reactive cells in normal or primed mouse spleen. 88 to greater than 98% of the activity of cytotoxic populations was removed by a single adsorption. However, normal spleen cells or spleen cells previously primed in vitro could not be depleted of their capacity to be sensitized, even when adsorption effectively removed all residual cytotoxic activity from the same previously primed population. In fact, exposure to an immunoadsorbent augmented the ultimate cytotoxicity generated in a nonspecific fashion. This augmentation was especially dramatic in the case of a previously primed population and may have reflected the removal of a nonspecific suppressor. If antigen-reactive precursors cannot be removed efficiently by adsorption, other approaches to the generation of tolerant lymphoid populations, such as specific suppression of precursor differentiation must be sought.


2008 ◽  
Vol 181 (11) ◽  
pp. 7721-7727 ◽  
Author(s):  
Amy K. Wesa ◽  
Christopher J. Herrem ◽  
Maja Mandic ◽  
Jennifer L. Taylor ◽  
Cecilia Vasquez ◽  
...  

1979 ◽  
Vol 149 (4) ◽  
pp. 856-869 ◽  
Author(s):  
T J Braciale

Purified type A influenza viral hemagglutinin stimulates an in vitro cell-mediated cytotoxic cell response that exhibits a high degree of specificity for the immunizing hemagglutinin. The response magnitude is proportional to the hemagglutinin dose used for stimulation. The lytic activity of the effector cells is H-2 restricted. Analysis of the specificity of the response indicated that these cytotoxic T cells readily distinguish target cells expressing serologically unrelated hemagglutinin from target cells bearing hemagglutinins serologically related to the stimulating hemagglutinin. Further analysis of the fine specificity of cytotoxic T-cell recognition with serologically cross-reactive type A influenza hemagglutinins revealed a hierarchy of cross-reactivity among these hemagglutinins that was the converse of the serologic hierarchy. These results are discussed in terms of possible differences and similarities in the specificity repertoire of cytotoxic T cells and antibodies. Possible implications of these findings from the standpoint of cytotoxic T-cell induction are also discussed.


1975 ◽  
Vol 141 (3) ◽  
pp. 584-599 ◽  
Author(s):  
B E Elliott ◽  
J S Haskill ◽  
M A Axelrad

Effector cells in delayed hypersensitivity and in vitro cytotoxicity were studied in lymph node cells from animals immunized with sheep erythrocytes (SRBC) in complete Freund's adjuvant. Delayed hypersensitivity response (DHR) was assayed by the increase in foot pad swelling after the intrafoot pad injection of immune cells plus antigen. Cell-mediated cytotoxicity against SRBC was assayed by a microcytotoxicity test with sheep fibroblasts as target cells. Effector cells were antigen specific, sensitive to anti-theta serum plus complement (C), and insensitive to anti-Ig serum plus C. A nonrosette-forming (non-RFC) small lymphocyte effector T cell and a rosette-forming medium lymphocyte effector T cell were isolated by velocity sedimentation. The small lymphocyte non-RFC required a longer time than the medium lymphocyte RFC effector cell to produce maximum activity. Buoyant density failed to distinguish medium lymphocyte effector cells in DHR and in vitro cytotoxicity.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2763-2763
Author(s):  
Xing Zhao ◽  
Narendiran Rajasekaran ◽  
Uwe Reusch ◽  
Michael Weichel ◽  
Kristina Ellwanger ◽  
...  

Abstract Introduction: CD19 is expressed by B cells from early development through differentiation into plasma cells, and represents a validated target for the development of therapeutic antibodies to treat B cell malignancies such as Non Hodgkin Lymphoma (NHL) and acute lymphoblastic leukemia (ALL). Different CD19-targeting T-cell engagers are investigated in clinical studies for the treatment of NHL or ALL, including Affimed's AFM11, a bispecific CD19/CD3 TandAb antibody, which is currently investigated in a phase 1 dose escalation study. Indeed, Affimed's bispecific tetravalent platform comprises not only T-cell engaging TandAbs with two binding sites for CD3, but also NK-cell recruiting TandAbs with two binding sites for CD16A. In the present study, Affimed's AFM11, was characterized and compared in in vitro and in vivo studies with the CD19/CD16A TandAb AFM12. Methods: Analogous to the CD19/CD3 TandAb AFM11, a bispecific tetravalent TandAb AFM12 was constructed with two binding sites for CD19 and two sites for CD16A. Both TandAbs were characterized side by side for their biophysical properties, binding affinities to CD19+ tumor target cells and to their respective effector cells by flow cytometry. Kinetics and dose-response characteristics were evaluated in in vitro cytotoxicity assays. Potency and efficacy of both TandAbs were compared on different CD19+ tumor target cell lines using primary human effector cells. To compare the efficacy of AFM11 and AFM12 a patient-derived tumor xenograft model was developed. Results: AFM12 mediated efficacious target cell lysis with a very fast on-set in vitro. Lysis induced by AFM11 was less efficacious (lower specific lysis than AFM12) but reproducibly more potent (lower EC50 value). In addition to the potency and efficacy of AFM11 and AFM12, different aspects of safety, such as effector cell activation in the presence and absence of target cells were investigated and will be described. Conclusions: Affimed's CD19/CD3 and CD19/CD16A TandAbs with identical anti-CD19 tumor-targeting domains but different effector cell-recruiting domains represent interesting molecules to study T-cell- or NK-cell-based immunotherapeutic approaches. The comparison of AFM11 and AFM12 demonstrated that AFM12-mediated lysis was fast and efficacious, whereas AFM11 showed a higher potency. In summary, the NK-cell recruiting TandAb AFM12 represents an alternative to T-cell recruiting molecules, as it may offer a different side effect profile, comparable to that of AFM13, the first NK-cell TandAb clinically investigated. Disclosures No relevant conflicts of interest to declare.


1989 ◽  
Vol 259 (3) ◽  
pp. 731-735 ◽  
Author(s):  
M Z Atassi ◽  
G S Bixler ◽  
T Yokoi

Presentation of a protein antigen to T cells is believed to follow its intracellular breakdown by the antigen-presenting cell, with the fragments constituting the trigger of immune recognition. It should then be expected that T-cell recognition of protein antigens in vitro will be independent of protein conformation. Three T-cell lines were made by passage in vitro with native lysozyme of T cells from two mouse strains (B10.BR and DBA/1) that had been primed with the same protein. These cell lines responded well to native lysozyme and very poorly to unfolded (S-sulphopropyl) lysozyme. The response of the T-cell lines to the antigen was major histocompatibility complex (MHC)-restricted. A line from B10.BR was selected for further studies. This line responded to the three surface-simulation synthetic sites of lysozyme (representing the discontinuous antigenic, i.e. antibody binding, sites) and analogues that were extended to a uniform size by a nonsense sequence. T-cell clones prepared from this line were specific to native lysozyme and did not respond to the unfolded derivative. Furthermore, several of these clones showed specificity to a given surface-simulation synthetic site. The exquisite dependency of the recognition by the clones on the conformation of the protein antigen and their ability to recognize the surface-simulation synthetic sites indicate that the native (unprocessed) protein was the trigger of MHC-restricted T-cell recognition.


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