CD8+CD45RA+CD27-CD28-T-cell subset in PBL of cervical cancer patients representing CD8+T-cells being able to recognize cervical cancer associated antigens provided by HPV 16 E7.
OBJECTIVE
In response to antigenic stimulation, naive MHC-class I restricted and antigen-specific CD8+CD45RA+CD28+T-cells undergo clonal expansion and differentiate into CD8+CD45RO+ memory T-cells. Upon re- encounter with the nominal antigen, CD45RO+ T-cells are able to convert to CD8+CD45RA+CD28-T-cells displaying potent immune effector functions, including TNF-alpha production. This T-cell subpopulation constitutes a minor population in healthy individuals. In the present study we are currently evaluating whether this particular T-cell subset in PBL represents CD8+T-cells which may be able to recognize cervical cancer associated antigens provided by HPV 16 E7.


METHODS
Flow-cytometric cell sorted CD8+CD45RA+CD28- and CD8+CD45RA+CD28-T-cells were obtained from patients with cervical cancer and tested for recognition of HLA-A2 restricted peptides derived from the human papillomavirus (HPV)16-E7 gene product using ELISA. HPV DNA in tumor tissue was detected by PCR.


RESULTS
We show that the effector CD8+CD45RA+CD28-T-cell subset is expanded in peripheral blood lymphocytes (PBL) from patients with cervical cancer, but also in PBL from patients with an acute mycobacterial infection. CD8+T-cells from 3/6 cancer patients showed a peptide-specific immune response which could be segregated in peptide epitopes which elicited either a strong TNF-alpha production, or GM-CSF and IL-2 secretion. Peptide-reactivity could exclusively be detected in the ex vivo freshly isolated CD8+CD45RA+CD28-T-cell population. A similar situation was found to be true for HLA-A2 presented peptide epitopes derived from M. tuberculosis-associated antigens presented to T-cells obtained from patients with tuberculosis.


CONCLUSIONS
The sorting of CD8+CD45RA+CD28-T-cells enables to determine the fine specificity of CD8+ effector T-cells without the need for in vitro manipulation and aids to define the most appropriate target epitopes for novel vaccine designs.
Pilch
H
H
Department of Obstetrics and Gynecology, Johannes Gutenberg-University of Mainz, Germany. HPilch3920@aol.com
Hoehn
H
H
Schmidt
M
M
Steiner
E
E
Tanner
B
B
Seufert
R
R
Maeurer
M
M
D000595:Amino Acid Sequence; D015703:Antigens, CD / Q000096:biosynthesis; D000956:Antigens, Viral / Q000276:immunology*; D018106:CD28 Antigens / Q000097:blood*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006650:Histocompatibility Testing; D006801:Humans; D017493:Leukocyte Common Antigens / Q000097:blood*; D008207:Lymphatic Metastasis; D009367:Neoplasm Staging; D027383:Papillomaviridae / Q000276:immunology*; D010446:Peptide Fragments / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000097:blood*; D002583:Uterine Cervical Neoplasms / Q000097:blood / Q000276:immunology* / Q000473:pathology / Q000601:surgery / Q000821:virology*
D015703:Antigens, CD; D000956:Antigens, Viral; D018106:CD28 Antigens; D016207:Cytokines; D010446:Peptide Fragments; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D017493:Leukocyte Common Antigens