Expression of the Human Milk Protein sCD14 in Tobacco Plant Cell Culture

The human milk protein sCD14 was expressed in tobacco plant cell cultures. Tobacco cells were transformed with a modified cd14 cDNA minus the GPI-tail and either the native human signal peptide (SP) or a plant SP, under the control of the CaMV-35S promoter. Transformants were screened using PCR and Southern blot analysis. The functionality of the inserted cDNA was checked by northern blot analysis for the presence of recombinant sCD14 mRNA. The detection of the protein has been observed by western blot analysis at an estimated level of 5 μg l⁻¹ in a non-soluble fraction of the culture medium.