Cutaneous squamous cell carcinoma and p53 codon 72 polymorphism: a need for screening?

The association between human papillomavirus (HPV)-associated cervical cancer and cutaneous squamous cell carcinoma and codon 72 polymorphism in the p53 gene is not unequivocal. Especially, it is not known whether carriers of the arginine form have an increased risk of cancer that necessitates screening. The alternative is that the polymorphism is a tumor marker instead of a risk factor. We set out a case-control study to determine the risk of squamous cell carcinoma of the skin in individuals with the p53 codon 72 arginine genotype in order to establish the possible need for screening. The distribution of the different p53 codon 72 genotypes was examined in 86 subjects with a history of cutaneous squamous cell carcinoma and in 168 controls. Additionally, 121 subjects who had had histologically proven basal cell carcinoma and 108 subjects who had had non-familial malignant melanoma were tested. p53 polymorphism was evaluated by polymerase chain reaction (PCR) using DNA samples from peripheral blood lymphocytes. In a subgroup of patients with squamous cell carcinoma and controls, the presence of epidermodyplasia verruciformis human papillomavirus (EV-HPV) DNA was determined in plucked eyebrow hair. Differences in the distributions of the genotypes among cases and controls were calculated, and univariate and multivariate analyses were performed to assess the risk to develop cutaneous squamous cell carcinoma in the presence of the p53 codon 72 arginine genotype. Frequency distributions of the three different genotypes (homozygous for the arginine allele, heterozygous for the two alleles, and homozygous for the proline allele) were similar among the squamous cell carcinoma group and the control group: 47.1%, 46.0% and 6.9% versus 47.8%, 45.8% and 6.4%, respectively. Statistical analysis showed no significant differences between these groups. In patients with squamous cell carcinoma and controls who harbored EV-HPV DNA in their plucked eyebrow hair, similar results were obtained. The distributions of the p53 codon 72 genotypes in the basal cell carcinoma and malignant melanoma group were also not significantly different from the control group. p53 codon 72 arginine homozygosity does not appear to represent a significant risk factor for cutaneous squamous cell carcinoma and screening seems not to be indicated. Mol. Carcinog. 30:56-61, 2001.

Antibodies against human papillomavirus type 16 and 18 E6 and E7 proteins in cervicovaginal washings and serum of patients with cervical neoplasia.

Serum antibodies against the E6 and E7 proteins of human papillomavirus (HPV) 16 and 18 are associated with cervical cancer. The aim of this study was to investigate the presence of local antibodies against HPV in cervicovaginal washings (CWs). In this study antibodies against the native HPV16 and HPV18 E6/E7 proteins were detectable in CWs (48%) and sera (29%) from patients with cervical cancer (n = 21) utilizing a sandwich protein enzyme-linked immunosorbent assay (ELISA). In paired CWs and sera from patients with cervical intraepithelial neoplasia (n = 38) and from healthy women (n = 22) no antibodies against these proteins were found. In 10 of 11 patients, the antibody response corresponded with the HPV type in the cervical smear and/or tumor tissue, which indicates the HPV type specificity of the assay. In 7 of 11 patients with antibody reactivity against HPV16 or HPV18 E6 and/or E7 proteins a higher level of antibody reactivity in the CWs than in the paired serum samples was found at similar inputs of total IgG. This suggests that the antibodies in the CWs against the investigated HPV proteins in these patients were locally produced.

A functional NF-kappaB binding site in the human papillomavirus type 16 long control region.

By computer search, we identified one potential NF-kappaB binding site in the HPV16 long control region (LCR) at position 7554-7563 having two mismatches in comparison to the consensus NF-kappaB binding site of the Igkappa L promoter. Bandshift experiments with nuclear extracts from HeLa cells or purified glutathione S-transferase-p65 fusion protein clearly demonstrated that NF-kappaB is able to bind to this region of the LCR. However, in comparison to NF-kappaB binding on a consensus probe, the affinity of NF-kappaB for this site is about 250-fold reduced. When mutations were introduced into this NF-kappaB binding site, the activity of the LCR was increased, strongly suggesting that NF-kappaB was acting as a transcriptional repressor in the context of the HPV16 LCR. In addition, overexpression of NF-kappaB p65 repressed the activity of the HPV16 LCR, strengthening this conclusion.

Transcriptional regulation of human papillomavirus type 16 LCR by different C/EBPbeta isoforms.

During genital human papillomavirus (HPV) infection several cytokines are released, such as interleukin-1 (IL-1), tumor necrosis factoralpha (TNFalpha), IL-6, and IL-8. These cytokines may play a role in the immune surveillance against viral infection. Two of these cytokines, IL-1 and TNFalpha, suppress the transcription of the HPV16 early genes. CAATT/ enhancer binding protein, (C/EBPbeta), which is activated by IL-1 and TNFalpha, has been suggested to act as a mediator of this transcriptional downregulation. C/EBPbeta contains three different translation initiation sites that can lead probably by leaky ribosome scanning to the generation of three isoforms of C/EBPbeta, namely full-length C/EBPbeta, liver enriched transcriptional activator protein (LAP), and liver enriched inhibitory protein (LIP). When transiently expressed in C33A and HeLa cells, the first two C/EBPbeta isoforms activate the HPV16 long control region (LCR). LIP, which acts as an antagonist of C/EBPbeta, represses the HPV16 LCR activity. Our observation that treatment of HeLa cells with IL-1 leads to induction of LIP supports the hypothesis that the LCR downregulation by IL-1 is mediated by LIP.

IgG antibodies against human papillomavirus type 16 E7 proteins in cervicovaginal washing fluid from patients with cervical neoplasia.

Little information is available about the cervicovaginal mucosal antibodies against human papillomavirus (HPV) proteins. In this study specific IgG antibodies against HPV 16 E7 protein were determined in paired samples of cervicovaginal washing fluid and serum from patients with cervical cancer (n = 22), cervical intraepithelial neoplasia (CIN) (n = 38), healthy individuals (n = 22), and serum from children (n = 41) by a radioactive immunoprecipitation assay (RIPA). HPV 16 E7 specific IgG antibodies were found in cervicovaginal washings (n = 8) and in sera (n = 8) of the patients with cervical cancer. About 60% of the patients with HPV 16 positive cervical cancer had HPV 16 E7 specific IgG antibodies. Titration studies showed that the IgG antibody reactivity in cervicovaginal washings was higher than in the paired serum samples of six patients with cervical cancer (P < 0.001). In the CIN group we found no IgG reactivity in the serum, but in five patients we found a low IgG reactivity in the cervicovaginal washings. No IgG reactivity was found in cervicovaginal washings and sera from healthy individuals and sera from children. HPV 16 E7 specific IgG antibodies seem to be locally produced in a number of patients with HPV 16 positive (pre)malignant cervical lesions. For more definitive evidence for the local production of these antibodies immunostaining should be performed to demonstrate the presence of specific anti-HPV 16 E7 IgG producing plasma cells in the cervical epithelium.

Conserved TcR beta chain usage for a single MHC class II-restricted heat shock protein peptide.

Previously we have shown that the T-cell response against the HLA-DR3 (17)-restricted heat shock protein (Mr 65 000)-derived peptide amino acids (aa) 3-13 (hsp65 aa 3-13) is recognized by the exclusive usage of the TRBV5 gene as well as a conserved CDR3 region in a tuberculoid leprosy patient. In the present study we analyzed the TcR of T-cell clones specific for hsp65 aa 3-13 derived from three healthy individuals with a response level similar to that of the leprosy patient. We show that unlike the tuberculoid leprosy patient, healthy high responders have a diverse T-cell response to hsp65 aa 3-13. However, a striking observation was made: even though high responders have a diverse specific TcR repertoire, TRBV5-expressing clones from two healthy individuals could be isolated that were nearly identical to a dominant clone in the tuberculoid leprosy patient. In conclusion, the data show that restriction of TcR specific for an antigen correlates with the presence of that antigen in disease. However, the preferred TcR can also be detected in healthy high responders. A natural infection in vivo, as with the tuberculoid leprosy patient, may be responsible for the observed trimming and preferential outgrowth of a certain TcR.

Analysis of T-cell clonality in bone marrow of patients with acquired aplastic anaemia.

Acquired aplastic anaemia (AA) represents a state of bone marrow (BM) failure which is characterized by BM hypocellularity and pancytopenia. It has been hypothesized that in some AA patients, bone marrow failure is secondary to the targeted destruction of haemopoietic stem cells by autoreactive T cells. The response of T cells to antigenic stimulation has been shown, in a number of animal models and in autoimmune diseases, to result in the (oligo)clonal expansion of positively reacting T cells. For this reason, we studied the utilization of 24 T-cell receptor-variable gene segments (TCRBV) and the clonality in BM aspirates and peripheral blood (PB) of seven AA patients. BM from transplant donors served as controls. Determination of TCRBV gene segment usage revealed no significant differences between patients and controls. Clonality within each family was analysed by single-strand conformation polymorphism (SSCP) analysis. Clonal and clonally predominant bands were seen in BM of three AA patients in five to eight TCRBV families. Clonal rearrangements were encountered less often in BM of control subjects. In conclusion, our results suggest an antigen-driven T-cell response in the BM of predominantly AA patients resulting in oligoclonal T-cell outgrowth.

Molecular analysis of the T-cell receptor beta-chain repertoire in early rheumatoid arthritis: heterogeneous TCRBV gene usage with shared amino acid profiles in CDR3 regions of T lymphocytes in multiple synovial tissue needle biopsies from the same joint.

To gain insight into the nature of the immune response with respect to accumulation and composition of the T-cell receptor (TCR) repertoire in synovial tissue in rheumatoid arthritis (RA), we have determined the nucleotide sequence of TCRBV regions transcribed by T lymphocytes derived from synovial tissue. Synovial tissue was obtained by needle biopsies from three different sites of the same joint in two early RA patients. We found that the TCRBV region repertoire among synovial tissue-infiltrating mononuclear cells was heterogeneous when the different biopsies taken from each patient were compared. However, DNA sequence analysis of TCRBV rearrangements of synovial T lymphocytes showed conserved amino acid usage profiles in the CDR3 domains of different TCRBV regions, which exhibited an individual specific character. These CDR3 motifs were not present in paired samples of peripheral blood. The existence of homologous CDR3 amino acid profiles within the TCRBV regions derived from synovial tissue is indicative of an antigen-driven immune response.

Direct assessment of junctional diversity in rearranged T cell receptor beta chain encoding genes by combined heteroduplex and single strand conformation polymorphism (SSCP) analysis.

In order to define the extent of T cell heterogeneity and clonality, unique DNA sequences in the junctional region in rearranged T cell receptor (TcR) genes can be studied. For this purpose we have adapted a non-denaturing nucleic acid gel electrophoresis procedure to detect TcR junctional diversity. Detection of junctional diversity is based upon electrophoretic separation of single stranded (ss) and double stranded (ds) DNA molecules via mobility shifts due to nucleotide sequence polymorphism. To examine the capacity of this nucleic acid gel electrophoresis procedure to detect nucleotide sequence polymorphism in the CDR 3 region within TcR V beta gene family sequences polymerase chain reaction (PCR) amplified TcR V beta 5.1/5.4 and V beta 14 cDNA sequences were analyzed. The results of this study showed that (1) the single strand conformation polymorphism (SSCP) procedure has a low capacity to discriminate between diverse TcR V beta cDNA sequences due to comigration of the ssDNA molecules, which results in an underestimation of the heterogeneity in a given T cell population; (2) comigrating ssDNA and/or dsDNA (homoduplex) molecules can be separated by the formation of heteroduplex molecules; these heteroduplex molecules provide essential additional information on the degree of nucleotide sequence polymorphism in the CDR 3 region within the TcR V beta cDNA sequences; (3) the double strand conformation polymorphism (DSCP) procedure provides a fast and reliable procedure to detect junctional diversity within the sequences tested. Using DSCP a more detailed assessment of amplified TcR V beta cDNA sequences can be obtained as compared with SSCP analysis only. Data obtained by gel analysis were very similar to those obtained by conventional bacterial cloning and DNA sequencing procedures on the corresponding cDNA clones. In conclusion, this new gel electrophoresis procedure allows a direct assessment of the extent of T cell heterogeneity and clonality by screening junctional diversity in TcR chain encoding sequences in clinical conditions with (oligo)clonal expansion of T lymphocytes.

Clonal dominance and selection for similar complementarity determining region 3 motifs among T lymphocytes responding to the HLA-DR3-associated Mycobacterium leprae heat shock protein 65-kd peptide 3-13.

In order to establish whether specific MHC class II-peptide complexes are capable of selecting TCR V regions, we investigated in detail the TCR beta chain used in the recognition of HLA-DR3 restricted hsp65 peptide 3-13 in a tuberculoid leprosy patient. Using RT-PCR, a clear dominance of the TCRBV5 gene family was observed in a hsp65 peptide 3-13-specific T-cell line; however, not in fresh, unstimulated PBMCs, PHA-stimulated PBMCs, or a T-cell line specific for tetanus toxoid. DNA sequence analysis of the TCR V regions, comprising TCRBV5 genes, derived from the hsp65 peptide 3-13-specific T-cell line revealed the exclusive usage of the TCRBV55S1 gene segment and a predominance of one V-D-J gene rearrangement, which is indicative of clonal expansion of these T lymphocytes. Additional highly similar V-D-J gene rearrangements were detected at a low level in this hsp65 peptide 3-13 specific T-cell line. These conserved junctional regions (CDR3 regions) could not be detected within the TCRBV5 gene family of fresh PBMCs, PHA-stimulated PBMCs, hsp65, and tetanus-toxoid-specific T-cell lines from this patient. The observations in this tuberculoid leprosy patient reveal that an HLA class-II-restricted T-cell response results in selection of TCRBV regions which are highly similar in amino acid composition to the CDR3 region within the expanding TCRBV regions.

T-cell receptor usage of interleukin-2-responsive peripheral gamma delta T cells.

The majority of human peripheral gamma delta T cells express the V gamma 9 gene in combination with the V delta 2 gene. The diversity of this subset of gamma delta T cells is limited by a preferential usage of the J gamma P gene segment and a highly distinctive junctional motif of the T-cell receptor (TCR) delta chain. We and others have observed that peripheral blood derived V gamma 9+V delta 2+ gamma delta T cells of healthy individuals are activated after stimulation with interleukin-2 (IL-2) in vitro, but only a small percentage of gamma delta T cells subsequently proliferates. To assess whether the proliferating, IL-2-responsive gamma delta T cells represent a selective group of T cells, we have analysed TCR junctional features of IL-2-responsive gamma delta T cells. Out of 30 individuals studied, nine were identified as IL-2-responders and three as IL-2-hyperresponders. The TCR V(D)J gene usage from IL-2 stimulated peripheral blood lymphocytes of these IL-2-(hyper)responsive individuals was analysed. The results showed that in most individuals gamma delta T cells polyclonally expanded after stimulation with IL-2. In two IL-2-hyperresponder individuals, however, a monoclonal expansion of a particular V gamma 9+V delta 2+ gamma delta T cell was found. In one of these individuals, this V gamma 9+V delta 2+ T-cell clone expressed a very rare gamma delta TCR type because of the presence of an Ala within the junctional region at a conserved position relative to V delta framework residues (delta 97), which is very infrequently used by peripheral blood V gamma 9+V delta 2+ cells. This particular clonotype could also be detected in unstimulated PBL samples taken from that individual, and made up for 30% of the total peripheral gamma delta T-cell pool. These data indicate that in general IL-2-responsive V gamma 9+V delta 2+ gamma delta T cells represent a polyclonal population, reflecting in vivo stimulation with multiple antigens or superantigens. In contrast, monoclonal expansions of gamma delta T cells after stimulation with IL-2 can also occur, which may be related to an in vivo stimulation by one particular antigen, rendering this gamma delta T-cell type dominant in the peripheral blood.

Identification of two distinct function gamma delta TCR complexes on the surface of a human T cell clone.

In this study we describe the expression of two T cell receptor (TCR) gamma chains on the surface of a human T cell clone isolated from the peripheral blood. Each gamma chain was part of an independent and functional TCR. The dual receptor T cell clone (and all subclones derived from this clone) had stable expression of this phenotype. Immunoprecipitation studies revealed the expression of non-disulfide linked TCRs by this V gamma 4+V gamma 9+V delta 1+ T cell clone, which was in agreement with the finding that both V gamma gene transcripts were rearranged to C gamma 2-associated joining elements. Both gamma chains were derived from productive rearrangements of different (allelic) genes coding for a V gamma 4+ and a V gamma 9+ gamma-chain, and both were coupled to a V delta 1+ delta chain. Incubation of this V gamma 4+V gamma 9+V delta 1+ T cell clone with TCR gamma-chain-specific MoAbs rapidly induced an increase in intracellular Ca++, indicating that both gamma-chains are functional. Furthermore, this clone responded to stimulation with S. aureus derived superantigens. We suggest therefore that exogenous (super)antigens can trigger dual receptor T cells resulting in activation of these T cells.

Therapeutic regulation of T cells in rheumatoid arthritis.

TCR repertoire studies in RA have yielded conflicting data. These studies were initiated on the premise that clonal expression of T cells at the site of inflammation could serve as a target for immune therapies designed on the basis of the option to inactivate or eliminate the presumed pathogenic T cells. These analyses have demonstrated the existence of a highly diverse overall TCR repertoire on the basis of extensive usage of TCR V genes both in synovial fluid and tissue. However, clusters of RA patients can be recognized who share increased usage frequencies of defined TCR V genes among synovial fluid or synovial tissue lymphocytes. Subsequent analysis of the CDR3 regions among diverse overall TCR repertoires have revealed the presence of conserved amino acid sequences in the CDR3 regions of the variable portions of TCRs in T lymphocytes derived from the site of inflammation. These findings suggest that a selective, antigen-driven expansion of T lymphocytes is occurring in the inflamed joints. Parallel to the TCR-repertoire studies, we investigated whether vaccines prepared from synovial T cells could modulate T-cell reactivity. The studies were based on previous work on TCV in animals, revealing that attenuated non-specific T-cell lines could serve as a vaccine. The results obtained in 13 RA patients showed no clear indication for a cellular or humoral immune response. Our experience with TCV in RA patients showed that this technique is feasible and safe. We found some evidence for a modulated T-cell reactivity both in vivo and in vitro. These results show at least some immunomodulatory effect af T-cell vaccination, although the antigen specificity of the effect of this intervention remains to be shown. Because of the convincing studies in animals and MS patients, further studies in RA should focus on the effect of vaccination using vaccines prepared from disease-inducing cells. In this respect, determination of the CDR3 regions of synovial T cells could lead to the identification of those T cells that are relevant for the disease.

Limited restriction in the TCR-alpha beta V region usage of antigen-specific clones. Recognition of myelin basic protein (amino acids 84-102) and Mycobacterium bovis 65-kDa heat shock protein (amino acids 3-13) by T cell clones established from peripheral blood mononuclear cells of monozygotic twins and HLA-identical individuals.

We have analyzed the TCR-alpha beta repertoire specific for a given peptide/MHC complex by using pairs of HLA-identical individuals ranging from monozygotic twins to unrelated individuals to examine the contribution of genetic background and HLA expression in shaping the potential response to a single antigenic epitope. This panel has been previously defined, demonstrating that the concordance of the peripheral TCR-alpha beta repertoires directly correlates to the level of relation and HLA identity. We have analyzed peptide-specific T cell clones derived from T cell lines from these individuals specific for MHC class II-restricted peptides: Mycobacterium bovis 65-kDa heat shock protein (65-kDa hsp) amino acids (aa) 3-13 (DR3-restricted), and myelin basic protein aa 84-102 (DR2-restricted). DNA sequence analysis was used to determine the composition of the TCR-alpha beta V regions. Although the overall TCR-alpha beta repertoires between individuals were diverse, an intra-individual limited restriction was evident. There was also a limited conservation in the response to the different peptides: high frequencies of V beta 2, 4, 7, 19, V alpha 21, and J alpha 17 responded to the MBP aa84-102, whereas these V/J regions were limited or absent in the 65-kDa hsp aa3-13 repertoire. Similarly, V beta 5.1 and J alpha 9 were increased in the 65-kDa hsp aa3-13 repertoire. Within the CDR3s, motifs could be identified that were similar between twins. Furthermore, one of these motifs resembled CDR3s previously found in corresponding animal models. Similarities could also be seen in the CDR3s of T cell clones sharing V gene usage and peptide specificity. Thus, the in vitro response to antigenic peptides seems to be quite heterogeneous overall and individual specific.

Joint-derived T cells in rheumatoid arthritis proliferate to antigens present in autologous synovial fluid.

The histopathological features of rheumatoid joint-inflammation suggest that an antigen-driven activation of T cells plays a central role in the onset and/or perpetuation of the inflammatory process. However, the disease-associated antigens responsible for the activation of T cells in the joint are unknown. In this project we study the response of IL-2 expanded T-cell lines from the synovial fluid (SF) of rheumatoid arthritis (RA) patients against autologous SF in a proliferation assay. Sixteen out of 32 RA patients were found to have CD4+ T cells that proliferate in response to autologous SF. The presence of T cells able to respond to SF antigens in inflamed joints suggests that these T cells play an active role in the pathogenesis of RA. T cell clones reactive to autologous SF were isolated from SF-derived T-cell lines of two RA patients. All clones were of the CD4+, CD8-, alpha/beta+ phenotype. SF-reactivity of T-cell clones from the DR4/DR12-positive RA patient was restricted via the Dw4 subtype of DR4. SF reactivity of T cells of the DR12/DR15 patient was DP-restricted. Some of the T-cell clones responded specifically to autologous and not to allogeneic SF, whereas others revealed responsiveness against a limited number of allogeneic SF samples. The (restricted) specificity of T cells towards autologous SF antigens is indicative for heterogeneity of the epitopes recognized and argues against ubiquitous nonpolymorphic joint constituents as the relevant antigens recognized by the SF-autoreactive T cells.