Seledtsov Victor I, Seledtsova Galina V
Immanuel Kant Baltic Federal University, Kaliningrad, Russia.
Institute for Fundamental and Clinical Immunology, Novosibirsk, Russia.
Front Immunol. 2017 Apr 6;8:409. doi: 10.3389/fimmu.2017.00409. eCollection 2017.
Variable regions of both B-cell receptors (BCRs) and T-cell receptors (TCRs) are completely formed in the postnatal period, and, consequently, no innate immune tolerance against these structures exists in adulthood. Indeed, antibodies (Abs) specific to TCRs have been found in both animals and humans. These facts clearly indicate the existence of B cells able to directly interact with T cells through binding of BCRs to TCRs without implicating major histocompatibility complex molecules. A novel paradigm is proposed in that the immune memory is based on idiotype/anti-idiotype interactions occurring between BCRs and TCRs following clearance of the antigen that elicited immune responses. It is envisaged that direct contact between memory T and B cells could provide co-stimulatory signals needed to sustain viability, growth, and differentiation of the interacting immune cells. In contrast, plasma cells originating from memory B-cells could produce anti-TCR Abs that inhibit direct BCR-to-TCR interactions, thereby downregulating the B- to T-cell contact-based immune memory a negative feedback mechanism.
B细胞受体（BCR）和T细胞受体（TCR）的可变区在出生后完全形成，因此成年后不存在针对这些结构的先天免疫耐受性。事实上，在动物和人类中都发现了针对TCR的抗体（Ab）。这些事实清楚地表明存在能够通过BCR与TCR结合直接与T细胞相互作用的B细胞，而无需涉及主要组织相容性复合体分子。提出了一种新的范式，即免疫记忆基于引发免疫反应的抗原清除后BCR与TCR之间发生的独特型/抗独特型相互作用。可以设想，记忆T细胞和B细胞之间的直接接触可以提供维持相互作用的免疫细胞的活力、生长和分化所需的共刺激信号。相比之下，源自记忆B细胞的浆细胞可以产生抑制BCR与TCR直接相互作用的抗TCR抗体，从而下调基于B细胞与T细胞接触的免疫记忆——一种负反馈机制。
