scholarly journals The Function and Oncological Significance of PD-L1 and its Antibodies

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Shreya Nagunuri ◽  
Ananya Garg ◽  
Jagath Reddy Junutula

The PD-L1 protein, also known as programmed death-ligand 1 is a protein encoded in the CD274 gene. Specifically, PD-L1 belongs to the immunoglobulin superfamily of proteins, and it is a transmembrane protein that allows nutrients across the cell membrane 11. PD-L1 works in close connection with T cells (thymus cells) and B cells (bone marrow or bursa-derived cells)1. PD-L1 binds to the PD-L receptor on T cells to regulate and sometimes inhibit (in the case of cancer) the activated T cells, B cells, and myeloid cells. Once their activation is inhibited by PD-L1, the T-cells are unable to fight foreign substances in the body like infections, diseases, and cancers, thus allowing cancerous tumors to grow without check3. Elevated levels of PD-L1 have been found in a variety of cancers, including melanoma, non-small cell lung cancer (NSCLC), Hodgkin’s lymphoma, bladder cancer, renal cell carcinoma (RCC), head and neck squamous cell carcinoma (HNSCC), breast cancer, Merkel cell carcinoma, hepatocellular carcinoma (HCC) and gastric cancer (GC)4. Among other information, this study also examines the protein sequence of PD-L1, alignments of the sequence, the structure, functional domains, gene expression, copy number, and mutation profiles.

1973 ◽  
Vol 137 (2) ◽  
pp. 411-423 ◽  
Author(s):  
John W. Moorhead ◽  
Curla S. Walters ◽  
Henry N. Claman

Both thymus-derived (T) and bone marrow-derived (B) lymphocytes participate in the response to a hapten 4-hydroxy-3-iodo-5-nitrophenylacetic acid (NIP), coupled to a nonimmunogenic isologous carrier, mouse gamma globulin (MGG). Spleen cells from mice immunized with NIP-MGG show increased DNA synthesis in vitro when cultured with NIP-MGG. The participation of and requirement for T cells in the response was demonstrated by treating the spleen cells with anti-θ serum. This treatment resulted in a 77% inhibition of the antigen response. Furthermore, adoptively transferred normal thymus cells could be specifically "activated" by NIP-MGG in vivo and they responded secondarily to the antigen in vitro. The active participation of B cells in the secondary response was demonstrated by passing the immune spleen cells through a column coated with polyvalent anti-MGG serum. Column filtration reduced the number of NIP-specific plaque-forming cells and NIP-specific rosette-forming cells (both functions of B cells) and produced a 47% inhibition of the NIP-MGG response. The ability of the cells to respond to phytohemagglutinin (PHA) was not affected by column filtration showing that T cells were not being selectively removed. The participation of B cells in the in vitro NIP-MGG response was also shown by treatment of the spleen cells with antiserum specific for MGG and MGG determinants. B cells were removed by treatment with anti-IgM or polyvalent anti-MGG serum plus complement, resulting in a respective 46 and 49% inhibition of the response to NIP-MGG. (Treatment with anti-IgM serum had no effect on T cells.) The contribution of the hapten NIP to stimulation of T cells was investigated using NIP-MGG-activated thymus cells. These activated T cells responded in vitro very well to the NIP-MGG complex but not to the MGG carrier alone demonstrating the requirement of the hapten for T cell stimulation. The response was also partially inhibited (41%) by incubating the activated cells with NIP coupled to a single amino acid (epsilon-aminocaproic acid) before addition of NIP-MGG. These results demonstrated that T cells recognize the hapten NIP when it is coupled to the isologous carrier MGG.


1971 ◽  
Vol 133 (6) ◽  
pp. 1325-1333 ◽  
Author(s):  
Klaus-Ulrich Hartmann

Spleen cells of bone marrow chimeras (B cells) and of irradiated mice injected with thymus cells and heterologous erythrocytes (educated T cells) were mixed and cultured together (17). The number of PFC developing in these cultures was dependent both on the concentration of the B cells and of the educated T cells. In excess of T cells the number of developing PFC is linearly dependent on the number of B cells. At high concentrations of T cells more PFC developed; the increase in the number of PFC was greatest between the 3rd and 4th day of culture. Increased numbers of educated T cells also assisted the development of PFC directed against the erythrocytes. It is concluded that the T cells not only play a role during the triggering of the precursor cells but also during the time of proliferation of the B cells; close contact between B and T cells seems to be needed to allow the positive activity of the T cells.


1975 ◽  
Vol 141 (3) ◽  
pp. 547-560 ◽  
Author(s):  
A Basten ◽  
J F Miller ◽  
R Abraham

The relationship between H-2 complex-associated determinants, Fc receptors, and specific antigen-recognition sites on T and B cells was examined by binding and functional assays. The Fc receptor was detected by radiolabeled immune complexes or aggregated human IgG. Both these reagents selectively bound to B cells, not to T cells. When spleen cells, from mice primed to several antigens, were exposed to highly substituted radioactive aggregates, their capacity to transfer both a direct and indirect plaque-forming cell response to these antigens was abrogated. Addition of B cells, but not of T cells, restored responsiveness. Complexed Ig binding to Fc receptors was prevented by pretreatment of mixed lymphoid cell populations with antisera directed against membrane components on the same cell (e.g., H-2) and on other cells (e.g., theta). The lack of specificity of inhibition was thought to be due to the formation on cell surfaces of antigen-antibody complexes which would then attach to the Fc receptor during the incubation precedure. Specific blockade of the Fc receptor during the incubation procedure. Specific blockade of the Fc receptor however occurred when B cells were pretreated with the Fab fragments of anti-H-2 antibody. This was demonstrated autoradiographically and by inhibition of aggregate-induced suicide. The blocking activity of ante-H-2 Fab was removed by absorption with spleen cells from thymectomized irradiated mice but not with thymus cells of appropriate specificity. This suggested that the antibodies involved had specificity for determinants on the B-cell membrane distinct from those coded by the K or D end of the H-2 complex, and either absent from, or poorly represented on, thymus cells. Specific antigen-induced suicide of B cells was achieved simply by incubating the cells with radioactive antigen in the cold. T-cell suicide on the other hand required that the 125I-labeled antigen be presented to the T cells at 37 degrees-C on the surface of spleen cells from antigen-primed mice. Pretreatment of T cells with the Fab fragment of anti-H-2 antibody protected them from the suicide effect. By contrast no such protection of B cells could be achieved by this procedure. In other words H-2 (? Ir)-associated determinants may not only be in close proximity to the antigen-binding site on T cells but, in addition, may be involved in the effective operation of the receptor.


Blood ◽  
1993 ◽  
Vol 81 (12) ◽  
pp. 3343-3349 ◽  
Author(s):  
BK Link ◽  
GJ Weiner

Abstract Bispecific monoclonal antibodies (bsabs) recognizing both CD3 and a tumor antigen can redirect T-cell-mediated cytotoxicity toward cells bearing that antigen. Such bsabs have been shown to be more effective than monospecific monoclonal antibodies (MoAbs) at preventing tumor growth in animal models of B-cell malignancy. The current studies describe the production and preliminary evaluation of a bsab designed to induce the lysis of malignant human B cells by human T cells. The bsab was obtained from a hybrid-hybridoma cell line produced by fusing OKT3-secreting hybridoma cells with hybridoma cells that secrete 1D10. 1D10 is an MoAb that recognizes an antigen found on a majority of malignant human B cells that has not been detected to a significant degree on normal resting or activated lymphocytes. High performance liquid chromatography (HPLC) was used to separate bsab from monospecific antibodies that were also present in the hybrid-hybridoma antibody product. The bsab was then evaluated in vitro for its ability to induce lysis of malignant B cells by activated T cells. The bsab consistently induced extensive lysis in vitro of 1D10 (+) cells, including both cell lines and cells obtained from patients with a variety of B-cell malignancies. No such effect was seen with activated T cells alone or activated T cells with monospecific antibody. No increased lysis was seen with 1D10 (-) cell lines. The bsab also mediated lysis of malignant B cells by autologous T cells. We conclude bsab containing an OKT3 arm and a 1D10 arm can induce T-cell-mediated lysis in a manner that is both potent and specific. This supports further evaluation of this bsab as a potential immunotherapy of B-cell malignancy.


1984 ◽  
Vol 160 (6) ◽  
pp. 1919-1924 ◽  
Author(s):  
L K Jung ◽  
S M Fu

A monoclonal antibody, AB1, was established with activated human B cells as immunogen. AB1 stained activated B cells but not activated T cells. Its selective reactivity to activated B cells was further documented by its nonreactivity to activated T cells, resting T and B cells, monocytes, granulocytes, bone marrow cells, leukemic cells, and cells from cell lines of T, B, and myeloid lineages. Upon activation, the antigen appeared on B cells as early as 3-4 h after stimulation and was fully expressed by 38 h. The expression of this antigen was not dependent on the presence of B cell stimulatory factor(s). Anti-IgM antibodies by themselves induced its expression. AB1 inhibited B cell proliferation that was induced by a low dose anti-IgM antibody and conditioned medium containing B cell stimulatory factor. It did not inhibit B cell proliferation induced by either high doses of anti-IgM antibodies or by formalinized Staphylococcus aureus. It also failed to inhibit T cell mitogenesis. The possibility exists that this antigen is related to the receptor for B cell stimulatory factor.


1999 ◽  
Vol 11 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Gerry G. B. Klaus ◽  
Mary Holman ◽  
Caroline Johnson-Léger ◽  
Jillian R. Christenson ◽  
Marilyn R. Kehry

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