Ancient BCMA-like Genes Herald B Cell Regulation in Lampreys

The relationship between the clearance of HBsAg and the remodeling of B cell subsets in CHB patients treated with Peg-IFN-α

Background

The seroconversion of the hepatitis B antigen is the ideal outcome for long-acting interferon-pegylated interferon-α (Peg-IFN-α) treatment among patients with chronic hepatitis B (CHB). B-cell response plays an important role in the process of hepatitis B antigen clearance, but the specific mechanism by which B-cell improve hepatitis B virus (HBV) is still unclear.

Methods

A total of 103 CHB patients participated in this study. The patients received 24 weeks of Peg-IFN-α treatment. Flow cytometry was used to detect B-cell surface markers’ cluster of differentiation cluster of differentiation CD19, CD24, and CD27 in the peripheral blood mononuclear cells (PBMCs) of CHB patients before and after 24 weeks of Peg-IFN-α treatment.

Results

After 24 weeks of Peg-IFN-α treatment, the content of memory B cells (CD19⁺CD27⁺) and effector B cells (CD19⁺CD38⁺) increased significantly. Further analysis showed that the clearance of the hepatitis B antigen was correlated with the change value, ΔT, of plasma cells before and after treatment. The B-cell subsets (CD19⁺CD24⁺; CD19⁺CD40⁺; CD19⁺CD40⁺; CD19⁺CD80⁺), was also tested and the results showed that CD19⁺CD24⁺ and CD19⁺CD80⁺ content also increased significantly after treatment.

Conclusions

After Peg-IFN-α treatment, the B-cell subsets of CHB patients are remodeled. Thus, Peg-IFN-α treatment appears to play an important role in the remodeling of B cell subsets and the clearance of HBV antigens. The results of this study provide a theoretical basis and guidance for the clinical treatment of CHB.

The immune system of jawless vertebrates: insights into the prototype of the adaptive immune system

Jawless vertebrates diverged from an ancestor of jawed vertebrates approximately 550 million years ago. They mount adaptive immune responses to repetitive antigenic challenges, despite lacking major histocompatibility complex molecules, immunoglobulins, T cell receptors, and recombination-activating genes. Instead of B cell and T cell receptors, agnathan lymphocytes express unique antigen receptors named variable lymphocyte receptors (VLRs), which generate diversity through a gene conversion-like mechanism. Although gnathostome antigen receptors and VLRs are structurally unrelated, jawed and jawless vertebrates share essential features of lymphocyte-based adaptive immunity, including the expression of a single type of receptor on each lymphocyte, clonal expansion of antigen-stimulated lymphocytes, and the dichotomy of cellular and humoral immunity, indicating that the backbone of the adaptive immune system was established in a common ancestor of all vertebrates. Furthermore, recent evidence indicates that, unlike previously thought, agnathans have a unique classical pathway of complement activation where VLRB molecules act as antibodies instead of immunoglobulins. It seems likely that the last common ancestor of all vertebrates had an adaptive immune system resembling that of jawless vertebrates, suggesting that, as opposed to jawed vertebrates, agnathans have retained the prototype of vertebrate adaptive immunity.

Characterization of lamprey (Lampetra japonica) tnfr10-like gene: A potential granulocyte marker molecule and its immune functions

Tumor necrosis factor receptor superfamily (TNFRSF) is an ancient protein superfamily. By binding to tumor necrosis factor (TNF), it can participate in inflammatory response, apoptosis, lymphocyte homeostasis and tissue development. Seven TNFR members have previously been identified in lampreys but detailed functions of TNFR members are not yet to be resolved. Here, we demonstrate some of the distinguishing features of TNFR10-like member which belongs to TNFRSF. The immunohistochemical results indicate that the TNFR10-like protein is abundant in vascular epithelial cells of the lamprey typhlosole and gills. The expression of tnfr10-like gene has a significantly increased at transcription level after Vibrio anguillarum, Staphylococcus aureus and Poly (I:C) stimulation. Notably, TNFR10-like is specifically expressed in the granulocytes of lamprey peripheral blood and supraneural body. Besides, overexpression tnfr10-like gene in HEK-293 T cells cause a decrease in cell activity and able to activate nuclear transcription factor-κB (NF-κB). Together, these results imply that L-TNFR10-like may play a vital role as a potential marker in lamprey granulocytes and may also be involved in regulation of immune response mediated by itself.