Inhibition of Staphylococcal Enterotoxin B-Induced Lymphocyte Proliferation and Tumor Necrosis Factor Alpha Secretion by MAb5, an Anti-Toxic Shock Syndrome Toxin 1 Monoclonal Antibody
Bibliographic record
Abstract
Toxic shock syndrome (TSS) is primarily caused by toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxin B (SEB). These toxins belong to a family of pyrogenic toxin superantigens (PTSAgs) produced by Staphylococcus aureus and exhibit several shared biological properties, including the induction of massive cytokine release and Vbeta-specific T-cell proliferation. The crystal structures of most PTSAgs are now published, and they demonstrate a striking similarity in conformational architecture even though their primary protein sequences are different. Despite these structural and immunobiological similarities, no cross-reactivity between TSST-1 and other PTSAgs has been demonstrated in serological or neutralization assays. Our laboratory has developed a neutralizing murine anti-TSST-1 monoclonal antibody (MAb5) which displayed cross-reactivity with SEB by enzyme-linked immunosorbent assay. The aim of the present study was to evaluate whether MAb5 can also cross-neutralize SEB-induced superantigenic activities in vitro. MAb5 was found to partially inhibit SEB-induced T-cell mitogenesis (63%) and tumor necrosis factor alpha (TNF-alpha) secretion (70%) in human peripheral blood mononuclear cells (PBMC) in a dose-dependent manner, while an isotypic anti-TSST-1 monoclonal antibody showed no effect. Epitope mapping revealed that MAb5 bound to TSST-1 residues 47 to 56 ((47)FPSPYYSPAF(56)) and to SEB residues 83 to 92 ((83)DVFGANYYYQ(92)), sequences that located in different regions of these toxins and are structurally dissimilar. SEB peptide (83)DVFGANYYYQ(92) was synthesized and found to also inhibit SEB-induced mitogenesis and TNF-alpha secretion in human PBMC. Our results demonstrate for the first time that MAb5 binds to different epitopes on TSST-1 and SEB that appear functionally important in inducing T-cell mitogenesis and TNF-alpha secretion in vitro.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".