New type of natural antibodies reactive to cytotoxic T lymphocyte-directed cancer vaccine peptides

A Special Connection between γδ T Cells and Natural Antibodies?

Natural antibodies (NAbs) play an important role in early host defense, autophagy and tissue remodeling, and in immune regulation. They arise spontaneously (without specific immunization), and are already present at birth. NAbs are produced by B1 B cells, MZ B cells and other B cell types. They include all major Ig subclasses but IgM antibodies are prevalent, especially early in development. NAbs may be poly-specific, recognize particular auto-antigens, or detect neo-determinants such as those exposed during apoptosis or generated by oxidation. NAbs do not require cognate T cell help but depend on soluble mediators produced by T cells. Our recent studies suggest that γδ T cells may have a special relationship with NAbs, and play a prominent role in their regulation, in part through the fine-tuning of IL-4 levels. The spontaneously activated state of these cells likely enables their cytokine production and other functions in the absence of external stimulation. Ontogenetically, the earlier arising γδ T cells are better positioned than αβ T cells to shape the developing repertoire of NAbs. Intriguingly, ligand specificities of NAbs and γδ T cell receptors appear to be overlapping, perhaps allowing γδ cognate help for certain NAb specificities. Via NAbs, γδ T cells could exert a regulatory influence on numerous processes in health and disease.

Tip110: Physical properties, primary structure, and biological functions

HIV-1 Tat-interacting protein of 110kDa (Tip110), also referred to as squamous cell carcinoma antigen recognized by T cells 3 (Sart3), p110 or p110(nrb), was initially identified as a cDNA clone (KIAA0156) without annotated functions. Over the past twenty years, several functions have been attributed to this protein. The proposed biological functions include roles for Tip110 in pre-mRNA splicing, gene transcription, stem cell biology, and development. Dysregulation of Tip110 is also a contributing factor in the development of cancer and other human diseases. It is clear that our understanding of this protein is rapidly evolving. In this review, we aimed to provide a summary of all the existing literature on this gene/protein and its proposed biological functions.

Nonmutated Self-Antigen-Derived Cancer Vaccine Peptides Elicit an IgE-Independent but Mast Cell-Dependent Immediate-Type Skin Reaction without Systemic Anaphylaxis

We previously reported an unexpected phenomenon, i.e., several cancer vaccine peptides, including a cyclophilin B-derived peptide (CypB-84), elicited an immediate-type skin reaction in prevaccination skin tests. These peptides were prohibited in the subsequent vaccinations because of a possible induction of systemic anaphylaxis. In this study, we investigated mechanisms involved in the peptide-elicited inflammatory reactions in BALB/c mice whose MHC class I molecule (Kd) shared similar binding motifs with the human HLA-A24 molecule. Among 11 peptides tested, all of which had been scheduled for use in clinical trials with HLA-A24+ cancer patients, three peptides (CypB-84, ART1-170, and ART4-13) elicited immediate footpad reactions in BALB/c mice similar to the skin reactions in humans. The footpad reaction was also observed in C57BL/6, athymic nu/nu, and CB17-SCID mice, but not in mast cell-deficient WBB6F1w/wv mice, indicating the reaction was not mediated by specific immunity, but was mast cell-dependent. Furthermore, the reactions were not correlated to in vivo antitumor effects of the peptides. An anaphylaxis was not elicited when the peptides were systemically injected due to a very rapid clearance of the peptides from the plasma by in vivo degradation. These results suggest that certain peptides of cancer vaccine candidates exhibit an IgE-independent but mast cell-dependent inflammatory response with no elicitation of systemic anaphylaxis, and may provide new insights for further development of peptide-based vaccinations for cancer patients.