UNLABELLED Staphylococcal enterotoxin B (SEB) is a potent toxin that is produced by Staphylococcus aureus strains and is classified as a category B select agent. We have previously shown that monoclonal antibody (MAb) 20B1, a murine anti-SEB IgG1, successfully treats SEB-induced lethal shock (SEBILS) and bacteremia that is caused by SEB-producing S. aureus. In this study, we have generated two ...

Human immunodeficiency virus (HIV) infection-associated B-cell hyperstimulation, in particular, the chronic stimulation of B cells to undergo isotype switching, may play an important role in the pathogenesis of acquired immunodeficiency syndrome-associated lymphoma (AIDS lymphoma). Isotype switching can be induced by various immune system factors, including cytokines, cell-surface stimulatory m...

To study the immunotherapeutic potential of monoclonal antibodies (mAbs) directed against the human pan-B-cell antigen CD19, a xenotransplantation model was developed in which the human Burkitt's cell line Daudi is s.c. transplanted into nude mice. IgG1, IgG2b, and IgG2a isotype variants of the anti-CD19 mAb (CLB-CD19) were tested for their capacity to inhibit the growth of 10 x 10(6) Daudi cel...

The purpose of the study was to determine if an intensive pre- season training program modifies the inflammatory status in professional soccer players and if this inflammatory profile may be associated with the physical state. We compared plasma protein biomarkers, using proteomics, and the physiological state and cardiac function in 12 professional soccer players and 9 recreational soccer play...

All jawed vertebrates produce immunoglobulins (IGs) as a defense mechanism against pathogens. Typically, IGs are composed of two identical heavy chains (IGH) and two identical light chains (IGL). Most tetrapod species encode more than one isotype of light chains. Chicken is the only representative of birds for which genomic information is currently available and is an exception to the above rul...

By generating four IgG isotype-switch variants of the high affinity 34-3C anti-erythrocyte autoantibody, and comparing them to the IgG variants of the low affinity 4C8 anti-erythrocyte autoantibody that we have previously studied, we evaluated in this study how high affinity binding to erythrocytes influences the pathogenicity of each IgG isotype in relation to the respective contributions of F...

The protective efficacy of mAbs to Cryptococcus neoformans glucuronoxylomannan depends on Ab isotype. Previous studies in A/JCr and C57BL/6J mice showed relative protective efficacy of IgG1, IgG2a >> IgG3. However, we now report that in C57BL/6J x 129/Sv mice, IgG3 is protective while IgG1 is not protective, with neither isotype being protective in 129/Sv mice. IgG1, IgG2a, and IgG3 had differe...

The finding that the antibody (Ab) constant (C) region can influence fine specificity suggests that isotype switching contributes to the generation of Ab diversity and idiotype restriction. Despite the centrality of this observation for diverse immunological effects such as vaccine responses, isotype-restricted antibody responses, and the origin of primary and secondary responses, the molecular...

Diversity in cytoskeleton organization and function may be achieved through variations in primary sequence of tubulin isotypes. Recently, isotype functional diversity has been linked to a "tubulin code" in which the C-terminal tail, a region of substantial sequence divergence between isotypes, specifies interactions with microtubule-associated proteins. However, it is not known whether residue ...

Vitamin C, one of essential micronutrients, has been reported to modulate the humoral immune responses in some mammals. We investigated whether vitamin C might modulate this response in mice by directly affecting B cells. Splenic B cells were isolated and activated by CD40- and B cell receptor-ligation in vitro. The cells were cultured with a pretreatment of vitamin C from 0 to 1 mM of concentr...