The contribution of Luis M. Allende and Manuel Hernández is equal and the order of the authorship is arbitrary.
A novel CD18 genomic deletion in a patient with severe leucocyte adhesion deficiency: a possible CD2/lymphocyte function-associated antigen-1 functional association in humans
Version of Record online: 25 DEC 2001
Volume 99, Issue 3, pages 440–450, March 2000
How to Cite
Allende, L. M., Hernández, M., Corell, A., García-pérez, M. A., Varela, P., Moreno, A., Caragol, I., García-martín, F., Guillén-perales, J. , Olivé, T., Español, T. and Arnaiz-villena, A. (2000), A novel CD18 genomic deletion in a patient with severe leucocyte adhesion deficiency: a possible CD2/lymphocyte function-associated antigen-1 functional association in humans. Immunology, 99: 440–450. doi: 10.1046/j.1365-2567.2000.00960.x
- Issue online: 25 DEC 2001
- Version of Record online: 25 DEC 2001
- Received 13 July 1999; revised 15 September 1999; accepted 13 October 1999.
Leucocyte adhesion deficiency (LAD) is an autosomal-recessive genetic disease that is characterized clinically by severe bacterial infections and caused by mutations in the CD18 gene that codes for the β2 integrin subunit. A patient with a severe LAD phenotype was studied and the molecular basis of the disease was identified as a single homozygous defect in a Herpes virus saimiri (HVS)-transformed T-cell line. The defect identified involves a deletion of 171 bp in the cDNA that encodes part of the proteic extracellular domain. This genetic abnormality was further studied at the genomic DNA level and found to consist of a deletion of 169 bp (from − 37 of intron 4 to + 132 of exon 5), which abolishes the normal splicing and results in the total skipping of exon 5. The 171-bp shortened ‘in-frame’ mRNA not only resulted in the absence of CD18 expression on the cell surface but also in its absence in the cytoplasm of HVS T-cell lines. Functionally, the LAD-derived HVS T-cell lines showed a severe, selective T-cell activation impairment in the CD2 (but not in the CD3) pathway. This defect was not reversible when exogenous interleukin-2 (IL-2) was added, suggesting that there is also a functional interaction of the lymphocyte function-associated antigen-1 (LFA-1) protein in the CD2 signal transduction pathway in human T cells, as has been previously reported in mice and in the human Papillon–Lefèvre syndrome. Thus, HVS transformation is not only a suitable model for T-cell immunodeficiency studies and characterization, but is also a good system for investigating the immune system in pathological conditions. It may also be used in the future in cellular models for in vitro gene-therapy trials.