B-Lymphocytes

The activity of a crude extract formulation was evaluated in experimental amoebic liver abscess in golden hamsters and in immunomodulation studies. The formulation comprises the following five plants-Boerhavia diffusa, Tinospora cordifolia, Berberis aristata, Terminalia chebula and Zingiber officinale. The formulation had a maximum cure rate of 73% at a dose of 800 mg/kg/day in hepatic amoebiasis reducing the average degree of infection (ADI) to 1.3 as compared to 4.2 for sham-treated controls.

Ageing in immune reactivity is described at the level of lymphoid cells, at that of lymphoid organs and organ function, and at that of regulation of cell and organ function. Apart from shifts in numbers of lymphoid cell subpopulations, the decrease in communication capacity between lymphoid cell populations and in binding of invaders (like bacteria) is an important aspect of ageing. These aspects may contribute to the decreased immune reactivity to invaders and the enhanced incidence of immune reactions to self-components (autoimmune reactivity).

An extension of the mathematical model of immunological tolerance including two categories of B and T helper cells, each having a different lifespan, is presented. The simulated recovery from tolerance is compared with experimental data on B and T helper cell tolerance to human gamma globulin (HGG) induced in adult mice. The performed simulation runs suggest the conclusion that in this case it seems impossible to incorporate a high ratio of both, long-lived B cells and/or short-lived T helper cells, if good agreement with the available experimental data should be preserved.

BACKGROUND: MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression and play a critical role in development, homeostasis, and disease. Despite their demonstrated roles in age-associated pathologies, little is known about the role of miRNAs in human aging and longevity. RESULTS: We employed massively parallel sequencing technology to identify miRNAs expressed in B-cells from Ashkenazi Jewish centenarians, i.e., those living to a hundred and a human model of exceptional longevity, and younger controls without a family history of longevity.

INTRODUCTION: B-cell depletion has become a common treatment strategy in anti-TNF-refractory rheumatoid arthritis (RA). Although the exact mechanism of how B-cell depletion leads to clinical amelioration in RA remains to be elucidated, repetitive treatment with B-cell-depleting agents leading to long-term B-cell depletion has been reported to be beneficial. The latter has led to the hypothesis that the beneficial effects of B-cell depletion might act through their influence on pathogenic autoreactive plasma cells.

BACKGROUND: MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression and play a critical role in development, homeostasis, and disease. Despite their demonstrated roles in age-associated pathologies, little is known about the role of miRNAs in human aging and longevity. RESULTS: We employed massively parallel sequencing technology to identify miRNAs expressed in B-cells from Ashkenazi Jewish centenarians, i.e., those living to a hundred and a human model of exceptional longevity, and younger controls without a family history of longevity.

The B cell arm of adaptive immunity undergoes significant modifications with age. Elderly people are characterized by impaired B cell responses reflected in a reduced ability to effectively respond against viruses and bacteria. Alterations of immunity with advancing age (immunosenescence) have been widely studied in centenarians who are considered a good example of successful aging. In recent years, attention has shifted to centenarian offspring (CO) as a model of people genetically advantaged for healthy aging and longevity.

B cells are critical players in the orchestration of properly regulated immune responses, normally providing protective immunity without autoimmunity. Balance in the B cell compartment is achieved through the finely regulated participation of multiple B cell populations with different antibody-dependent and independent functions. Both types of functions allow B cells to modulate other components of the innate and adaptive immune system. Autoantibody-independent B cell functions include antigen presentation, T cell activation and polarization, and dendritic cell modulation.

Systemic lupus erythematosus (SLE) is a complex heterogeneous disease, posing challenges to clinical trials. As in other autoimmune diseases, B-lymphocytes play a central role in lupus pathogenesis. The finding that selection and survival of B cells are controlled by a variety of signals, including those provided by the longevity factor BAFF (B-cell activating factor), also called BLyS (B-lymphocyte stimulator), led to preclinical trials that revealed that BAFF represents a promising therapeutic target for human lupus. Belimumab is a fully human monoclonal antibody directed against BAFF.

Antibody production is an important feature of the vertebrate immune system. Antibodies neutralize and clear pathogens, thereby protecting against infectious diseases. Such humoral immunity has great longevity, often persisting for the host's lifetime. Long-lived humoral immunity depends on help provided by CD4(+) T cells, namely T follicular helper (TFH) cells, which support the differentiation of antigen-specific B cells into memory and plasma cells.