Excessive amounts of mu heavy chain block B-cell development

Lysosomal transmembrane protein 5: Impact on immune cell function and implications for immune-related deficiencies

Lysosomal transmembrane protein 5 (LAPTM5) is a lysosomal-associated protein that interacts with surface receptors on various immune cells, including B cells, T cells, macrophages and dendritic cells. Dysregulated expression of LAPTM5 is implicated in the development of multiple immune system-related diseases. In the context of tumors, elevated LAPTM5 levels in immune cells are associated with decreased cell membrane levels of T cell receptors (TCR) or B cell receptors (BCR), leading to impaired antigen presentation and immune escape, thereby promoting tumor progression. Besides, LAPTM5 is critical for inducing non-apoptotic cell death in tumor parenchymal cells since its downregulation leads to inhibition of the cell death pathway in the tumor parenchyma and subsequent enhanced tumorigenesis. LAPTM5 also affects the cell cycle as the elevated LAPTM5 expression in solid tumors causes its inability to block the G0/G1 stage. In non-solid tumors, abnormal LAPTM5 expression disrupts blood cell development and causes irregular proliferation. Furthermore, in the nervous system, aberrant LAPTM5 expression in microglia is correlated with Alzheimer's disease severity. In this context, further preclinical research is essential to validate LAPTM5 as a potential target for diagnosis, therapy, and prognosis in immune-related disorders and tumors. This review summarized the current insights into LAPTM5's role in tumors and immune-related deficits, highlighting its potential as a valuable biomarker and therapeutic target.

Constitutive activation of NF-κB during early bone marrow development results in loss of B cells at the pro-B-cell stage

There is a considerable body of work exploring the role of NF-κB family of transcription factors in the maturation and functions of later stage B cells; however, their role in the earlier bone marrow stages of development is less well understood despite the demonstration that NF-κB activity is present at all early stages of B-cell development. To explore the consequences of early, B cell-targeted constitutive activation of both NF-κB pathways on B-cell development, we generated mice that have either or both. NF-κB pathways constitutively activated beginning in early pro-B cells. In marked contrast to activating a single pathway, we found mice with both pathways constitutively activated displayed a profound loss of B cells, starting with early pro-B cells and peaking at the late pro-B-cell stage, at least in part as a result of increased apoptosis. This effect was found to be cell autonomous and to have striking phenotypic consequences on the secondary lymphoid organs and circulating antibody levels. This effect was also found to be temporal in nature as similar activation under a Cre expressed later in development did not result in generation of a similar phenotype. Taken together, these findings help to shed further light on the need for tight regulation of the NF-κB family of transcription factors during the various stages of B-cell development in the bone marrow.

Terminal Deoxynucleotidyl Transferase (TdT) Inhibiti on of Cord Blood Derived B and T Cells Expansion

Purpose: Terminal deoxynucleotidyl transferase(TdT) is a DNA polymerase that is present in immature pre-B and pre-T cells. TdT inserts N-nucleotides to the V (D) J gene segment during rearrangements of genes, therefore, it plays a vital role in the development and variation of the immune system in vertebrates. Here we evaluated the relationship between cytokines like interleukin-2 (IL-2), interleukin-7 (IL-7), and interleukin-15 (IL-15) and TdT expression in cord blood mononuclear cells and also effect of inhibition in the expansion of B and T cells derived from cord blood. Methodes: The cord blood mononuclear cells were cultured with different combination of cytokines for 21days, which they were harvested in definite days (7, 14 and 21) and evaluated by flow cytometry. Results: Our data indicated that TdT expression increased in cord blood mononuclear cells using immune cell key cytokines without being dependent on the type of cytokines. TdT inhibition reduced both the expansion of B and T cells derived from cord blood and also declined the apoptosis and proliferation. Considered together, TdT played an important role in the control of the expansion of B and T cells derived from cord blood. Conclusion: considered together, it was observed that TdT expression was increased by cytokines and TdT inhibition not only reduced B and Tcells derived from cord blood, but it also affected the rate of apoptosis and proliferation.