Chromosomal localization 1 of tumor protein, translationally-controlled 1 (TPT1) encoding the human histamine releasing factor (HRF) to13q12→q14

The human histamine releasing factor (HRF; http://www. ncbi.nlm.nih.gov/htbin-post/Omin/dispim?600763) also called tumor protein, translationally controlled 1 (TPT1; http://www. gdb.org/) causes histamine release from basophils of certain allergic donors (MacDonald et al., 1995). It has identity to the translationally controlled tumor protein (TCTP, an alias for TPT1) which was previously designated as p23 (Bohm et al., 1989), and is highly conserved from man to alfalfa plants. While originally described as a growth-related tumor protein, it has also been identified in healthy liver tissue (Hughes et al., 1993) and more recently in macrophages, platelets, keratinocytes, erythrocytes, hepatocytes as well as tumor cells (Sanchez et al., 1997). The biologic function of TPT1 remained illusive until HRF was shown to cause histamine release from a subset of allergic donors’ basophils (MacDonald et al., 1995). We proposed that HRF produced this secretion by interaction with a subpopulation of IgE molecules that we termed IgE+. By definition, basophils expressing IgE– on their surface, did not support mediator release when stimulated with HRF. In a subsequent study, we were able to show that HRF enhanced IgE-dependent IL-4 and IL-13 secretion from all basophils (Schroeder et al., 1997). More recently, we have demonstrated that HRF promotes cytokine secretion and a calcium response in purified human eosinophils (Bheekha-Escura and MacDonald, manuscript submitted). Here we report the mapping of the gene encoding HRF (TPT1) to chromosome 13q12→q14. Of interest is the report showing a linkage on chromosome 13 of loci D13S270 and D13S153 to atopy via sibpair analysis (Daniels et al., 1996). Due to the fact that HRF activates cells important in the allergic diathesis, it’s gene could potentially be a candidate gene for allergies including allergic asthma. Therefore, it would be of considerable interest to determine if TPT1 maps close to those loci.