Oncolytic activity of NK cells against SW-756 squamous cervical carcinoma cell line: role of interferons alpha and gamma and CD54 adhesion molecule in oncolysis

No alteration in NK function or zeta chain expression in NK and T cells of cervical cancer patients

OBJECTIVE

To investigate in vitro natural killer (NK) cell activity and expression of signal-transducing zeta chains in patients with cervical cancer.

PATIENTS AND METHODS

Experiments were performed with frozen lymphocytes from patients at all disease stages and from healthy controls. Thawed NK were activated by overnight incubation in interferon-gamma (IFN-gamma); activity against two target cell lines was assessed by 4-h (51)Cr release assay. Targets chosen were K562, an erythroleukemic cell line, and a cervical carcinoma cell line designated 808. T and NK cell zeta chain expression was measured by flow cytometry.

RESULTS

Patients' NK were found to be as cytotoxic as those of normal controls against cell lines K562 and 808. Patient T and NK cells did not show significant down-regulation of the zeta chain.

CONCLUSIONS

We have found no evidence to suggest that loss of zeta chains is a mechanism for immunocompromise in patients with cervical carcinoma. IFN-recoverable patient NK activity is not reduced compared to matched controls. This may be clinically relevant since NK are active against cells exhibiting class I human leukocyte antigen (HLA) down-regulation and many cervical cancers show loss of HLA.