Conservation of Structure and Function Between Human and Murine IL-16
| Autor: | Joseph Keane, Nicoll, J., Kim, S., Wu, D. M. H., Cruikshank, W. W., Brazer, W., Natke, B., Zhang, Y., Center, D. M., Kornfeld, H. |
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| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.160.12.5945 |
| Popis: | IL-16 is a proinflammatory cytokine that signals via CD4, inducing chemotactic and immunomodulatory responses of CD4+ lymphocytes, monocytes, and eosinophils. Comparative analysis of murine and human IL-16 homologs could reveal conserved structures that would help to identify key functional regions of these cytokines. To that end, we cloned the murine IL-16 cDNA and found a high degree of amino acid similarity comparing the predicted murine and human IL-16 precursor proteins (pro-IL-16). The highest similarity (82.1%) was found in the C-terminal region, which is cleaved from pro-IL-16 to yield biologically active IL-16. Chemotaxis experiments with IL-16 of murine and human origin, using murine splenocytes or human T lymphocytes as targets, showed cross-species stimulation of motility. Synthetic oligopeptides and anti-peptide Ab were produced, based on the sequences of three predicted hydrophilic domains of IL-16 potentially presented in exposed positions. None of these peptides had intrinsic IL-16 bioactivity, but one (corresponding to a hydrophilic C-terminal domain of IL-16) partially displaced binding of OKT4 mAb to human lymphocytes. This peptide, and its cognate Ab, also inhibited IL-16 chemoattractant activity for human and murine cells. These studies demonstrate a high degree of structural and functional similarity between human and murine IL-16 and suggest that amino acids in the C terminus are critical for its chemoattractant function. The data suggest cross-species conservation of IL-16 receptor structures as well. Inhibitory peptides may be useful in disease states where the proinflammatory functions of IL-16 are detrimental to the host. |
| Databáze: | OpenAIRE |
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