Downloaded from www.microbiologyresearch.org by IP: 54.160.81.51 On: Mon, 19 Sep 2016 06:17:30 Journal of General Virology (1994),75, 2277-2284. Printed in Great Britain 2277 Cell-mediated immune responses to E7 peptides of human papillomavirus (HPV) type 16 are dependent on the HPV type infecting the cervix whereas serological reactivity is not type-specific Anna S. Kadish, 1. Seymour L. Romney, 2 Richard Ledwidge, ~ Robert Tindle, 4 Germain J. P. Fernando, 4 Sui Y. Zee, ~ Marc A. Van Ranst 3 and Robert D. Burk 3 Departments of 1 Pathology, 2 Obstetrics and Gynecology, and 3 Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, U.S.A, and 4Lions Human Immunology Laboratories, Queensland University, Brisbane, Australia Forty-two women attending a colposcopy clinic for evaluation of abnormal cervical cytology and 13 normal controls were studied for the presence of lymphocyte proliferation (LP) cell-mediated immune (CMI) res- ponses and serological reactivity to E7 peptides of human papillomavirus type 16 (HPV-16). HPV was typed by Southern blot hybridization of exfoliated cervicovaginal cell DNA. Positive LP responses (stimu- lation index /> 5-0) to one or more E7 peptides were observed in 28.6% (12 of 42) of patients and 23.1% (three of 13) of controls. Of patients infected with HPV- 16, -31 or -33, 63"6 % (seven of 11) showed a positive LP response compared with 14.3 % (two of 14) of women infected with other HPV types (P = 0.02), 17'6 % (three of 17) negative for HPV (P = 0.02) and 23"1% (three of 13) of controls (HPV status unknown) (P = 0"05). C- terminal peptide 109 (amino acids 72 to 97) elicited positive LP responses in 45.4 % (five of 11) of patients infected with HPV -16, -31 or -33 compared with 7"1% (one of 14) patients infected with other HPVs (P = 0.04), 5"9 % (one of 17) of women negative for HPV (P = 0"02) and 7"7% (one of 13) of controls (P = 0.05). HPV-16 group-specific LP responses of borderline significance were also observed against E7 peptides 103,105 and 108 (17-37, 37-54 and 62-80) (P = 0.07). ELISA reactivity (IgG) to E7 peptide 109 (72-97) was present in 7"7 % (one of 13) of controls, 35.3 % (six of 17) of HPV- negative patients, 42.9 % (six of 14) of patients infected with other HPVs, and only 9.1% (one of 11) of patients infected with HPV-16, -31 or -33. CMI responses to C-terminal HPV-16 E7 peptide 109 (72-97) were thus significantly related to ongoing cervical infection with HPV-16 and closely related types, whereas serological reactivity to E7 peptides was not HPV type-specific. Introduction Human papillomavirus (HPV) infection has been shown to be the major risk factor for the development of both premalignant disease and cancer of the uterine cervix (Morrison et al., 1991; Koutsky et al., 1992; Reeves et al., 1989). Of the HPV types known to infect the genital tract, of which there are more than 20, several types including HPV-16, -33 and -18 have been associated with the development of high-grade precancerous disease and cancer (Kadish et al., 1992; Lorincz et al., 1992). Of women with squamous intraepithelial lesions (SILs), a large proportion undergo regression, whereas others have persistent disease and a small number progress to invasive carcinoma (Schneider & Koutsky, 1992). Epi- demiological studies demonstrating increased prevalence and severity of HPV-induced lesions in immunosup- pressed patients (Vermund et al., 1991; Kiviat et al., 1990; Ho et al., 1994), in addition to histological studies of regressing genital HPV-induced lesions (Rogozinski et al., 1988) suggest that immune responses to HPV are critical in mediating the regression of disease. Studies of immune responses to HPV have been hampered by the difficulty in obtaining sufficient quan- tities of native HPV antigens. Bacterially expressed fusion proteins and synthetic peptides corresponding to the products of HPV open reading frames (ORFs) have been used to demonstrate cell-mediated immune (CMI) and humoral immune responses to HPV-encoded anti- gens in both human and murine systems (Dillner, 1990; Mtiller et al., 1990; Jenison et al., 1991; Jochmus- Kudielka et al., 1989; Tindle et al., 1990, 1991). The HPV-16-transforming proteins E6 and E7, which are abundantly expressed in precancerous and malignant cervical lesions (Stoler et al., 1992), have been shown to be tumour rejection antigens in murine systems (Chen et al., 1991, 1992). Human serological responses to HPV-16 E6 and E7 proteins have been reported to occur most 0001-2335 © 1994SGM