Killing of human leukaemia/lymphoma B cells by activated cytotoxic T lymphocytes in the presence of a bispecific monoclonal antibody (αCD3/αCD19)

ABSTRACT In order to test the hypothesis that CD8+ cytotoxic T lymphocytes mediate protection against acute superinfection, we depleted >99% of CD8+ lymphocytes in live attenuated simian immunodeficiency virus macC8 (SIVmacC8) vaccinees from the onset of vaccination, maintained that depletion for 20 days, and then challenged with pathogenic, wild-type SIVmacJ5. Vaccinees received 5 mg per kg of humanized anti-CD8 monoclonal antibody (MAb) 1 h before inoculation, followed by the same dose again on days 3, 7, 10, 13, and 17. On day 13, peripheral CD8+ T lymphocytes were >99% depleted in three out of four anti-CD8 MAb-treated vaccinees. At this time attenuated SIVmacC8 viral RNA loads in anti-CD8 MAb-treated vaccinees were significantly higher than control vaccinees treated contemporaneously with nonspecific human immunoglobulin. Lymphoid tissue CD8+ T lymphocyte depletion was >99% in three out of four anti-CD8 MAb-treated vaccinees on the day of wild-type SIVmacJ5 challenge. All four control vaccinees and three out of four anti-CD8 MAb-treated vaccinees were protected against detectable superinfection with wild-type SIVmacJ5. Although superinfection with wild-type SIVmacJ5 was detected at postmortem in a single anti-CD8 MAb-treated vaccinee, this did not correlate with the degree of preceding CD8+ T lymphocyte depletion. Clearance of attenuated SIVmacC8 viremia coincided with recovery of normal CD8+ T lymphocyte counts between days 48 and 76. These results support the view that cytotoxic T lymphocytes are important for host-mediated control of SIV primary viremia but do not indicate a central role in protection against acute superinfection conferred by inoculation with live attenuated SIV.

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C1.7 MONOCLONAL ANTIBODY DESIGNATES HIGH-AVIDITY CD4+ CYTOTOXIC T LYMPHOCYTES INVOLVED IN CLINICAL HEART REJECTION

Transplantation Journal ◽

10.1097/00007890-199807150-00024 ◽

1998 ◽

Vol 66 (1) ◽

pp. 135-138 ◽

Cited By ~ 8

Author(s):

Nancy E.M. van Emmerik ◽

Christiaan J. Knoop ◽

Leonard M.B. Vaessen ◽

Aggie H.M.M. Balk ◽

Bas Mochtar ◽

...

Keyword(s):

Monoclonal Antibody ◽

T Lymphocytes ◽

Cytotoxic T Lymphocytes ◽

High Avidity

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Generation of Antigen-Specific Cytotoxic T Lymphocytes with Peripheral B Cells Activated By α-Galactosylceramide

Blood ◽

10.1182/blood.v124.21.3838.3838 ◽

2014 ◽

Vol 124 (21) ◽

pp. 3838-3838

Author(s):

Sun Ok Yun ◽

Hee Young Ju ◽

Che Ry Hong ◽

Ji Won Lee ◽

Hyery Kim ◽

...

Keyword(s):

B Cells ◽

T Lymphocytes ◽

Cytotoxic T Lymphocytes ◽

Plasmid Dna ◽

Cell Activation ◽

Tumor Antigens ◽

Conflicts Of Interest ◽

Killing Activity ◽

Significant Difference

Abstract Dendritic cells (DCs) are well known as the most potent professional antigen presenting cells (APCs). Nonetheless, the use of these cells in immunotherapy has been limited due to the time consuming and laborious steps required to generate DCs from monocytes in vitro. Therefore, alternative APCs has drawn much attention because of their relative convenience in manipulation. In this study, the efficacy of B cells as APCs, as compared to DCs, in induction of cytotoxic T lymphocytes (CTLs) against cytomegalovirus (CMV)-specific antigens was evaluated. B cells were isolated by depletion of peripheral blood mononuclear cell (PBMCs) from healthy individuals with MACS system, loaded with α-galactosylceramide (α-GalCer) for inducing B cell activation, and nucleofected with CMV-antigen coding plasmid DNA, pCK-pp65-IRES-IE1. As other APCs, monocyte-derived DCs were induced with various cytokines (GM-CSF, IL-4, IL-1b, TNF-a), for 6 days and nucleofected with the same plasmid DNA. Ag-nucleofected B cells or DCs were cocultured with T cells for 14 days in vitro. The cells were harvested and subsequently immunoassayed. Proliferation of cells was more expanded by about 25~32% in CMV-CTLs induced by DCs compared to of B cells, but there was no significant difference in immunogenicity between CMV-CTLs induced with B cells and DCs. Compared to CMV-CTLs induced by DCs, the CTLs induced by α-GalCer-loaded B cells induced similar cytotoxicity against CMV antigen (Ag) in vitro. The CMV-CTLs by α-GalCer-loaded B cells recognized CMV antigen pp65 (median 88 SFC/105) and IE-1 (median 86 SFC/105) in donor 1, and CMV antigen pp65 (median 31 SFC/105) and IE-1 (median 37 SFC/105) in donor 2. Similarly, the CMV-CTLs by DCs recognized CMV antigen pp65 (median 133 SFC/105) and IE-1 (median 32 SFC/105) in donor 1, and CMV antigen pp65 (median 37 SFC/105) and IE-1 (median 43 SFC/105) in donor 2. Immunogenicities of both CTLs were similar not only on IFN-γ ELISPOT (Enzyme-linked immunospot) assay but also on cytotoxicity assay. The CMV-CTLs by α-GalCer-loaded B cells have killing activity against CMV antigen pp65 (100%, at E:T ratio 10:1) and IE1 (85%, at E:T ratio 10:1) in donor 1, and CMV antigen pp65 (69%, at E:T ratio 10:1) and IE1 (27%, at E:T ratio 10:1) in donor 2. Also, the CMV-CTLs by DCs show killing activity against CMV antigen pp65 (100%, at E:T ratio 10:1) and IE1 (42%, at E:T ratio 10:1) in donor 1, and CMV antigen pp65 (88%, at E:T ratio 10:1) and IE1 (64%, at E:T ratio 10:1) in donor 2. These observations suggest that α-GalCer-loaded B cells could be used in general as APCs instead of DCs. Using the B cells as APCs have several benefits such as cost-effectiveness, less time-consuming, and less laborious compared to when DCs are used. Furthermore, nucleofection technique might be useful in delivering antigen-coding DNA, not only for virus antigens but also for tumor antigens, directly into the nucleus. Our results demonstrate that α-GalCer-loaded B cells could be potent APCs in generating antigen-specific CTLs for cellular vaccines and adoptive immunotherapy. Acknowledgment: This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2012R1A1A2008316) and we thank Ann M. Leen, Helen E. Heslop and Malcomn K. Brenner from Center for Cell and Gene Therapy, Baylor College of Medicine Center for their kind help. Disclosures No relevant conflicts of interest to declare.

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CD40 activation does not protect chronic lymphocytic leukemia B cells from apoptosis induced by cytotoxic T lymphocytes

Blood ◽

10.1182/blood.v95.12.3853.012k37_3853_3858 ◽

2000 ◽

Vol 95 (12) ◽

pp. 3853-3858 ◽

Cited By ~ 1

Author(s):

Peter Chu ◽

William G. Wierda ◽

Thomas J. Kipps

Keyword(s):

B Cells ◽

Chronic Lymphocytic Leukemia ◽

T Lymphocytes ◽

Cytotoxic T Lymphocytes ◽

Lymphocytic Leukemia ◽

Target Cells ◽

Apoptosis Pathway ◽

Granule Exocytosis ◽

Concanamycin A ◽

Cd40 Activation

Cytotoxic T lymphocytes (CTLs) can kill target cells by the granule/exocytosis pathway or the Fas-mediated apoptosis pathway. The sensitivity of chronic lymphocytic leukemia (CLL) B cells to CTL-mediated apoptosis before and after CD40 activation was examined. Resting or CD40-activated CLL cells were found to be equally sensitive to class I–restricted CTL-mediated killing. Despite expressing CD95, the CD40-activated CLL target cells were found to be resistant to apoptosis induced by CH11, an IgM CD95 monoclonal antibody (mAb). Consistent with this, inhibitors of caspases, which are involved in the Fas-induced apoptotic pathway (eg, N-carbobenzoxy-Val-Ala-Asp fluoromethyl ketone [z-VAD-fmk]), were unable to block destruction of CLL target cells by CTL. In addition, preincubation of the effector T cells with the anti-Fas ligand mAb NOK-2 failed to inhibit their subsequent ability to kill CLL target cells. On the other hand, CTL activity was blocked by inhibitors of the granule exocytosis pathway such as ethylene-glyco-tetra-acetic acid or concanamycin A. These results indicate that CD40 activation does not impair the sensitivity of CLL cells to Fas-independent CTL-mediated apoptosis.

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Regulation of murine B cells through surface immunoglobulin. I. Monoclonal anti-delta antibody that induces allotype-specific proliferation.

Journal of Experimental Medicine ◽

10.1084/jem.152.5.1135 ◽

1980 ◽

Vol 152 (5) ◽

pp. 1135-1146 ◽

Cited By ~ 31

Author(s):

I M Zitron ◽

B L Clevinger

Keyword(s):

Monoclonal Antibody ◽

B Cells ◽

T Lymphocytes ◽

B Lymphocytes ◽

Soluble Form ◽

Spleen Cells ◽

Surface Immunoglobulin

We describe the identification of a monoclonal antibody that recognizes a determinant on the delta chain of mice of the Iga, allotype groups. The monoclonal Ig in soluble form induces allotype-specific proliferation by splenic B lymphocytes from normal animals of these haplotypes. Spleen cells from mice bearing the X-linked defect of CBA/N mice fail to respond, although they bear the determinant. Proliferation is independent of T lymphocytes. The data indicate a direct triggering function for sIgD.

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