T-Cell-Dependent Antibody Response: Assay Development in Cynomolgus Monkeys

Background4-1BB (CD137) is a co-stimulatory receptor that stimulates the function of multiple immune cells. Its ability to induce potent anti-tumor activity makes 4-1BB an attractive target for immuno-oncology. However, clinical development of a monospecific 4-1BB agonistic antibody has been hampered by dose-limiting hepatic toxicities. To minimize systemic toxicities, we have developed a novel Claudin18.2 (CLDN18.2) x 4-1BB bispecific antibody, TJ-CD4B (ABL111) that stimulates 4-1BB pathway only when it engages with Claudin 18.2, a tumor-associated antigen specifically expressed in gastrointestinal cancers. TJ-CD4B (ABL111) is now being evaluated in patients with advanced solid tumors in a first-in-human trial (NCT04900818).MethodsTJ-CD4B (ABL111) was evaluated in vivo using the human 4-1BB knock-in mice bearing CLDN18.2 expressing MC38 tumor cells. Pharmacodynamic effects upon treatment were characterized in tumor tissue and blood. Immunophenotyping of the tumor microenvironment (TME) and peripheral blood was performed by flow cytometry. Soluble biomarkers were measured using Luminex-based multiplex assay. In-depth gene expression analysis was performed on primary human CD8+ T cells that were co-cultured with CLDN18.2 expressing cells in the presence of anti-CD3 using NanoString nCounter®. Pharmacokinetic (PK) and toxicity study were performed in cynomolgus monkeys.ResultsTJ-CD4B (ABL111) elicited complete tumor regression in 13 out of 18 MC38 tumor bearing mice given at a dose above 2 mg/kg. Dose-dependent anti-tumor activity was associated with enhanced T cell activation in TME and expansion of memory T cells in the peripheral blood. Increased CD8+ T cells number and proliferation were observed in both tumor nest and surrounding stroma while the level of soluble 4-1BB in the serum was also elevated in response to the treatment. In vitro gene expression analysis by Nanostring revealed TJ-CD4B(ABL111) effectively activated immune pathways characterized by IFN?-signaling and T cell inflammation. Preclinically, TJ-CD4B was well tolerated at the repeated doses up to 100 mg/kg/wk in cynomolgus monkeys without the adverse influence on the liver function which is generally affected by 4-1BB activation. Besides, no cytokine release or immune activation was observed in the periphery.ConclusionsTJ-CD4B (ABL111) is a novel CLDN18.2 dependent 4-1BB bispecific agonist antibody that induced T cell activation and memory response in tumor with CLDN18.2 expression, leading to a strong anti-tumor activity in vivo. TJ-CD4B did not induce systemic immune response nor hepatic toxicity due to the CLDN18.2 dependent 4-1BB stimulation. These data warrant the current clinical development in phase I trial to validate the safety properties and tumor specific responses.

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Properties of the antigen-specific suppressive T-cell factor in the regulation of antibody response of the mouse. IV. Special subregion assignment of the gene(s) that codes for the suppressive T-cell factor in the H-2 histocompatibility complex.

Journal of Experimental Medicine ◽

10.1084/jem.144.3.713 ◽

1976 ◽

Vol 144 (3) ◽

pp. 713-725 ◽

Cited By ~ 238

Author(s):

T Tada ◽

M Taniguchi ◽

C S David

Keyword(s):

T Cell ◽

B Cells ◽

Antibody Response ◽

Gene Products ◽

T Cell Factor ◽

Recombinant Strains ◽

Histocompatibility Complex ◽

Effective Suppression ◽

Absorption Studies ◽

Lines Of Evidence

The locus of the gene that codes for the antigen-specific suppressive T-cell factor was determined to be in a new subregion "I-J" which locates between I-B and I-C subregions in the H-2 histocompatibility complex. This was shown by two different lines of evidence: (a) The absorbing capacity for the suppressive T-cell factor of several alloantisera against restricted I subregions did not correlate with their specificity for previously known Ia molecules which are coded for by genes in I-A and I-C subregions, but was associated with the specificity for the products of genes putatively present between I-B and I-C subregions. By the occurrence of special recombinant strains, i.e. B10.A(5R), B10.A(3R), B10.S(9R), and B10.HTT, which differ with respect to the I-J subregion, we were able to produce alloantisera which distinguish I-J subregion gene products. The absorption studies using these special alloantisera directed to I-J subregion clearly indicated that the suppressive T-cell factor is a product of I-J subregion gene(s), and that the molecule is distinct from known Ia molecules expressed on splenic B cells. (b) Taking advantage of the fact that there is a strict histocompatibility requirement for the effective suppression between the donor and recipient strains of the suppressive T-cell factor, we were able to determine the required identities of the genes in the H-2 complex existing among those present between I-B and I-C. Again, utilizing the T-cell factors obtained from special recombinant strains, i.e. B10.A(4R) and B10.A(5R), we were able to locate the gene that codes for the suppressive T-cell factor reactive only with relevant haplotype strains between I-B and I-C subregions. These results are most reasonably explained by the presence of a new subregion I-J which is specialized in coding for the suppressive T-cell factor as a different molecule from previously known Ia molecules.

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T Cell-Dependent Suppression of an Anti-Hapten Antibody Response

Immunological Reviews ◽

10.1111/j.1600-065x.1975.tb00178.x ◽

1975 ◽

Vol 26 (1) ◽

pp. 130-169 ◽

Cited By ~ 3

Author(s):

A. Basten ◽

J. F. A. P. Miller ◽

P. Johnson

Keyword(s):

T Cell ◽

Antibody Response

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Interference with Fc signals increases an antibody response by T-cell-deprived cultures to a T-dependent antigen

Cellular Immunology ◽

10.1016/0008-8749(87)90253-x ◽

1987 ◽

Vol 107 (2) ◽

pp. 465-470 ◽

Cited By ~ 19

Author(s):

Nicholas R.StC. Sinclair ◽

Angela Panoskaltsis

Keyword(s):

T Cell ◽

Antibody Response

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Comparison of the T Cell-Independent Antibody Response of Mice and Rats Exposed to 2,3,7,8-Tetrachlorodibenzo-p-dioxin

Toxicological Sciences ◽

10.1093/toxsci/32.2.293 ◽

1996 ◽

Vol 32 (2) ◽

pp. 293-297

Author(s):

RALPH J. SMIALOWICZ ◽

WANDA C. WILLIAMS ◽

MARIE M. RIDDLE

Keyword(s):

T Cell ◽

Antibody Response ◽

Tetrachlorodibenzo P Dioxin

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In vivo analysis of replication and immunogenicity of proviral clones of human T-lymphotropic virus type 1 with selective envelope surface-unit mutations

Blood ◽

10.1182/blood-2005-03-1076 ◽

2005 ◽

Vol 106 (10) ◽

pp. 3602-3608 ◽

Cited By ~ 10

Author(s):

Lee R. Silverman ◽

Andrew J. Phipps ◽

Andy Montgomery ◽

Soledad Fernandez ◽

Tomonori Tsukahara ◽

...

Keyword(s):

T Cell ◽

Antibody Response ◽

Virus Type ◽

Antibody Responses ◽

Envelope Gene ◽

Cell Leukemia Virus Type ◽

Surface Unit ◽

Human T Cell

AbstractHuman T-cell leukemia virus type 1 (HTLV-1) is the causative agent of adult T-cell lymphoma/leukemia (ATL). The HTLV-1 envelope gene exhibits limited variability when examined from infected individuals, but has not been tested using infectious clones of the virus in animal models. In vitro assays indicate that HTLV-1 envelope (Env) Ser75Ile, Asn95Asp, and Asn195Asp surface unit (SU) mutants are able to replicate in and immortalize lymphocytes. Herein, we examined the effects of these Env mutants in rabbits inoculated with HTLV-1 immortalized ACH.75, ACH.95, or ACH.195 cell lines (expressing full-length molecular clones with the SU mutations) or the ACH.1 cell line (expressing wild-type SU). All rabbits became infected, and the fidelity of the mutations was maintained throughout the 8-week study. However, SU point mutations resulted in decreased antibody responses to viral group-associated antigen (Gag) and Env antigens. ACH.195 rabbits had a selective decreased antibody response to SU, and one ACH.195 rabbit had an antibody response to both HTLV-1 and HTLV-2 SUs. Some mutant inoculation groups had altered proviral loads. However, peripheral-blood mononuclear cell (PBMC) proviral loads did not correlate with antibody responses. Our data are the first to demonstrate that mutations in critical determinants of HTLV-1 Env SU altered antibody responses and proviral loads, but do not prevent viral replication in vivo.

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