Immune Checkpoints of the B7 Family. Part 2. Representatives of the B7 Family B7-H3, B7-H4, B7-H5, B7-H6, B7-H7, and ILDR2 and Their Receptors1

A. I. Chapovala, b, 1, S. P. Chapovalc, N. S. Shcherbakovaa, d, and D. N. Shcherbakova, d

aRussian-American Anti-Cancer Center, Altai State University, Barnaul, 656049 Russia

bThe Biodesign Institute, Center for Innovation in Medicine, Arizona State University, Tempe, AZ 85281, USA

cDepartment of Microbiology and Immunology, Center for Vascular and Inflammatory Diseases, Program in Oncology, Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD, 21201, USA

dFSRI SRC VB Vector, Russian Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing, Koltsovo, Novosibirsk oblast, 630559 Russia

1Abbreviations: CAR, Chimeric Antigen Receptor; EAE, Experimental Autoimmune Encephalomyelitis; МНС, Major Histocompatibility Complex; TCR, T Cell Receptor; TNFα, Tumor Necrosis Factor α; Tregs, regulatory T-cells; Th1/Th2, T helper cells of type 1 or type 2; VEGF, Vascular Endothelial Growth Factor; АDCC, Antibody-Dependent Cellular Cytotoxicity; APC, antigen-presenting cell; DC, dendritic cell; CIA, Collagen-Induced Arthritis; LPS, Lipopolysaccharide; mAb, monoclonal antibody; ICM, immune checkpoint molecule; NK, normal killer; CTL, cytotoxic Т-lymphocyte.
1Corresponding author: phone: +7 (3852) 298-142; e-mail: andreichapoval@gmail.com.

Received 24 August, 2018

Abstract—Immune checkpoints regulate polarity, strength, and termination of the immune response. The leading roles in these processes are played by molecules of the B7 family. Based on data obtained using first representatives of the B7 family molecules, a two-signal model for T cells activation was proposed. The discovery of new homologues of B7-1 and B7-2 molecules revealed not only a great variety of their structural organization, but also new functions, for example the B7-H6 molecule is able to activate NK cells through interaction with NKp30 molecule. Manipulations of the B7 ligands and their interactions with specific receptors provide opportunities for fine tuning of the immune response against various pathogens and development of new drugs. The second part of this review provides information on recently discovered representatives of the B7 family, such as B7-H3, B7-H4, B7-H5, B7-H6, B7-H7, ILDR2, and their receptors.

Keywords: the B7 family, immune checkpoint molecules, immunotherapy, T-lymphocytes, the APC ligands

DOI: 10.1134/S1068162019050091