Proof-of-concept study of the caninized anti-canine programmed death 1 antibody in dogs with advanced non-oral malignant melanoma solid tumors

BACKGROUND

The anti-programmed death 1 (PD-1) antibody has led to durable clinical responses in a wide variety of human tumors. We have previously developed the caninized anti-canine PD-1 antibody (ca-4F12-E6) and evaluated its therapeutic properties in dogs with advance-staged oral malignant melanoma (OMM), however, their therapeutic effects on other types of canine tumors remain unclear.

OBJECTIVE

The present clinical study was carried out to evaluate the safety profile and clinical efficacy of ca-4F12-E6 in dogs with advanced solid tumors except for OMM.

METHODS

Thirty-eight dogs with non-OMM solid tumors were enrolled prospectively and treated with ca-4F12-E6 at 3 mg/kg every 2 weeks of each 10-week treatment cycle. Adverse events (AEs) and treatment efficacy were graded based on the criteria established by the Veterinary Cooperative Oncology Group.

RESULTS

One dog was withdrawn, and thirty-seven dogs were evaluated for the safety and efficacy of ca-4F12-E6. Treatment-related AEs of any grade occurred in 13 out of 37 cases (35.1%). Two dogs with sterile nodular panniculitis and one with myasthenia gravis and hypothyroidism were suspected of immune-related AEs. In 30 out of 37 dogs that had target tumor lesions, the overall response and clinical benefit rates were 6.9% and 27.6%, respectively. The median progression-free survival and overall survival time were 70 days and 215 days, respectively.

CONCLUSIONS

The present study demonstrated that ca-4F12-E6 was well-tolerated in non-OMM dogs, with a small number of cases showing objective responses. This provides evidence supporting large-scale clinical trials of anti-PD-1 antibody therapy in dogs.

Seroprevalence of Dermatophagoides farinae-specific IgE in dogs with atopic dermatitis in São Paulo, Brazil

Canine atopic dermatitis (CAD) is a chronic, inflammatory, and pruritic disease of the skin resulting from the loss of the epidermal barrier, sensitization, and exacerbated production of IgE antibodies mainly directed against environmental allergens, especially to house dust mites. To select specific allergen immunotherapies with high efficacy, there are necessary studies with house dust mite allergens to improve both serological and intradermal tests. Therefore, the objective of this study was to evaluate the seroprevalence of IgE against Der f 2, Zen 1, and crude Dermatophagoides farinae allergens in dogs with AD in the State of São Paulo, Brazil. The sera of 85 dogs with clinically confirmed atopic dermatitis from the State of São Paulo (Brazil) was collected. In addition, an indirect ELISA test was conducted to detect allergen-specific serum IgE. IgE seropositivity was observed in 97.5% of the dogs for Der f 2, 95.0% for Zen 1, and 92.5% for the crude mite allergens. Due to this high prevalence of IgE specific to these allergens, we suggest that Der f 2 and Zen 1 can be considered major allergens for dogs in the State of São Paulo.

Antimicrobial resistance and genotyping of Pseudomonas aeruginosa isolated from the ear canals of dogs in Japan

The strong bond between dogs and their owners creates a close association that could result in the transfer of antibiotic-resistant bacteria from canines to humans, potentially leading to the spread of antimicrobial resistance genes. Pseudomonas aeruginosa, a common causative agent of persistent ear infections in dogs, is often resistant to multiple antibiotics. Assessing the antimicrobial resistance profile and genotype of P. aeruginosa is crucial for the appropriate use of veterinary pharmaceuticals. However, in recent years, few studies have been conducted on this bacterium in Japan. We determined the antimicrobial resistance profile and genotype of P. aeruginosa isolated from the ear canal of dogs in Japan in 2020. Analysis of antimicrobial resistance using disk diffusion tests indicated a high frequency of resistance to most antimicrobial agents. Particularly, 29 isolates from the ear canals of the 29 affected dogs (100%) were resistant to cefovecin, cefpodoxime, and florfenicol; however, they were susceptible to cefepime and piperacillin/tazobactam. Only 3.4, 10.3, and 10.3% of the isolates were resistant to ceftazidime, tobramycin, and gentamicin, respectively. Furthermore, upon analyzing the population structure using multilocus sequence typing, a considerably large clonal complex was not observed in the tested isolates. Three isolates, namely ST3881, ST1646, and ST532, were clonally related to the clinically isolated sequence types in Japan (such as ST1831, ST1413, ST1812, and ST1849), which is indicative of dog-to-human transmission. Considering the variation in antibiotic resistance compared to that reported by previous studies and the potential risk of dog-to-human transmission, we believe that the survey for antimicrobial resistance profile and population structure should be continued regularly. However, the prevalence of multidrug-resistant P. aeruginosa in dogs in Japan is not a crisis.

Long-term survival of dogs with stage 4 oral malignant melanoma treated with anti-canine PD-1 therapeutic antibody: A follow-up case report

A monoclonal antibody targeting programmed cell death-1 (PD-1) is one of the most promising treatments for human cancers. Clinical studies in humans demonstrated that the anti-PD-1 antibody provides a long-lasting tumour response. Previously, we established an anti-canine PD-1 therapeutic antibody (ca-4F12-E6), and the pilot clinical study demonstrated that the antibody was effective in dogs with oral malignant melanoma (OMM). However, two OMM cases were still undergoing treatment when the pilot study was published. Here, we describe the long-term follow-up of those two cases. Although both cases showed long-term survival with complete response (CR), the tumour response differed; the effect onset was slow in one case and a durable response was observed in the second case even after treatment discontinuation. Secondary malignant tumours occurred during treatment in both cases. This follow-up study revealed that ca-4F12-E6 maintains CR in dogs for more than 1 year. In addition, the pattern of tumour response was unique compared to conventional therapy. These results indicate that new evaluation criteria for tumour response may be necessary for immunotherapy in veterinary medicine. Long-term follow-up is necessary regardless of the short-term treatment responsiveness.

Development of a monoclonal antibody for the detection of anti-canine CD20 chimeric antigen receptor expression on canine CD20 chimeric antigen receptor-transduced T cells

Chimeric antigen receptor (CAR) CAR-T cell therapy targeting CD20 can be a novel adoptive cell therapy for canine patients with B-cell malignancy. After injection of the CAR-T cells in vivo, monitoring circulating CAR-T cells is essential to prove in vivo persistence of CAR-T cells. In this study, we developed a novel monoclonal antibody against canine CD20 CAR, whose single-chain variable fragment was derived from the our previously reported anti-canine CD20 therapeutic antibody. Furthermore, we proved that this monoclonal antibody can detect therapeutic anti-canine CD20 chimeric antibody in the serum from healthy beagle dogs injected with the therapeutic antibody for safety study. This monoclonal antibody is a useful tool for monitoring both canine CD20-CAR-T cells and anti-canine CD20 therapeutic antibody for canine lymphoma.

Development of a cell line-based assay to measure the antibody-dependent cellular cytotoxicity of a canine therapeutic antibody

Antibody drugs are one of the most important therapeutic modalities in cancer treatment. Antibody drugs for canine cytotoxicity have been developed, and the most important way to evaluate the function of antibody drugs in vitro is to measure the antibody-dependent cellular cytotoxicity (ADCC) activity. However, a good method for measuring the ADCC activity of antibody drugs for dogs has not yet been developed. This study generated a cell line of NK-92 cells, a human natural killer cell line, transfected with canine CD16 and γ-chain as effector cells. A20 cells expressing canine CD20 were used as target cells, and a system for ADCC activity was established using an anti-dog CD20 antibody. The assay generated very consistent results. This is an applicable method for measuring canine ADCC activity and can be used for various antigen-antibody combinations to develop canine antibody drugs with cytotoxic activity in the future.

Evaluation of sensitization to the crude extract of Dermatophagoides farinae and its derived allergens, Der f 2 and Zen 1, in dogs with atopic dermatitis in Southern Brazil

BACKGROUND

Atopic dermatitis is associated with the production of IgE antibodies against environmental allergens and allergens of the house dust miteDermatophagoides farinae are frequently implicated in the disease.

OBJECTIVES

We aimed to observe the allergen-specific IgE against crudeD. farinae, Der f 2 and Zen 1 in dogs with atopic dermatitis and report if these dogs are in contact with material that could shelter mite allergens.

METHODS

100 dogs with clinical diagnosis of atopic dermatitis were included after exclusion of other forms of pruritic skin disease and dogs that already received specific or non-specific immunotherapy. These dogs were of different breeds and ages and they were presented at a veterinary teaching hospital and a private service of veterinary dermatology, both located in Curitiba, Southern Brazil. At the time of anamnesis, some questions were applied to know the possibility of these dogs having had contact with furniture and textile material which could shelter house dust mites. Sera samples were obtained and further analyzed by ELISA assay to measure serum IgE levels against these allergens with an established cut-off of 0.200 IgE optical density.

RESULTS

The allergen-specific IgE positivity against crudeD. farinae (92 %) and Zen 1 (77 %) was higher than Der f 2 (56 %). There was a correlation in sensitization to crude D. farinae and Zen 1 that was not observed between crude D. farinae and Der f 2 and Der f 2 and Zen 1. The sensitization to D. farinae and its allergens was associated with an unrestricted exposition to furniture and textile material. CONCLUSION & CLINICAL RELEVANCE: dogs with atopic dermatitis are frequently sensitized to D. farinae and its allergens, Der f 2 and Zen 1, may be considered major allergens in these dogs. Zen 1 may be the main allergen responsible for the sensitization to crude D. farinae.

Serum canine thymus and activation-regulated chemokine (TARC/CCL17) concentrations correlate with disease severity and therapeutic responses in dogs with atopic dermatitis

Background

Thymus and activation‐regulated chemokine (TARC/CCL17) has been implicated in the pathogenesis of canine atopic dermatitis (cAD). Serum TARC concentrations are a reliable biomarker for human atopic dermatitis; however, their potential as a biomarker for cAD has not been investigated.

Hypothesis/Objectives

To investigate whether serum TARC concentrations correlate with disease severity and therapeutic responses for cAD.

Animals

Thirty‐nine dogs with cAD and 42 healthy dogs were recruited.

Methods and materials

Serum TARC concentrations in dogs with cAD and healthy dogs were measured by sandwich ELISA with anti‐canine TARC antibodies. The clinical severity of cAD was scored using the validated Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI‐04). Serum TARC concentrations were compared between dogs with cAD and healthy controls, and their relationship with CADESI‐04 was examined. Serum TARC concentrations also were measured in 20 dogs with cAD treated with prednisolone or oclacitinib for four weeks.

Results

Serum TARC concentrations were significantly higher in dogs with cAD than in healthy dogs (P < 0.001). In dogs with cAD, serum TARC concentrations correlated with CADESI‐04 scores (ρ = 0.457, P < 0.01). Furthermore, serum TARC concentrations significantly decreased in treated dogs with the attenuation of clinical signs (P < 0.001). Changes in serum TARC concentrations before and after treatment correlated with those in CADESI‐04 scores (ρ = 0.746, P < 0.001).

Conclusions and clinical relevance

Serum TARC concentrations have potential as a clinical and research tool for the objective evaluation of disease severity and therapeutic responses for cAD.

Establishment of rat anti-canine DEP domain containing 1B (DEPDC1B) monoclonal antibodies

DEP domain-containing 1B (DEPDC1B) is involved in the regulation of cell de-adhesion and actin cytoskeleton activity during the G2/M transition of the cell cycle, and its overexpression has been proven to be associated with cancer progression in several human cancers. Canine DEPDC1B was identified as a gene that was overexpressed in canine lymphoma tissues in our previous study. However, in dogs, the protein expression of DEPDC1B remains to be determined due to the lack of a specific monoclonal antibody. Here, we developed rat monoclonal antibodies against canine DEPDC1B and characterized their applicability for immunodetection assays. Our findings demonstrated that these antibodies are functional and can be important tools to investigate the precise role of DEPDC1B in canine tumors.

Therapeutic Potential of an Endolysin Derived from Kayvirus S25-3 for Staphylococcal Impetigo

Impetigo is a contagious skin infection predominantly caused by Staphylococcus aureus. Decontamination of S. aureus from the skin is becoming more difficult because of the emergence of antibiotic-resistant strains. Bacteriophage endolysins are less likely to invoke resistance and can eliminate the target bacteria without disturbance of the normal microflora. In this study, we investigated the therapeutic potential of a recombinant endolysin derived from kayvirus S25-3 against staphylococcal impetigo in an experimental setting. First, the recombinant S25-3 endolysin required an incubation period of over 15 minutes to exhibit efficient bactericidal effects against S. aureus. Second, topical application of the recombinant S25-3 endolysin decreased the number of intraepidermal staphylococci and the size of pustules in an experimental mouse model of impetigo. Third, treatment with the recombinant S25-3 endolysin increased the diversity of the skin microbiota in the same mice. Finally, we revealed the genus-specific bacteriolytic effect of recombinant S25-3 endolysin against staphylococci, particularly S. aureus, among human skin commensal bacteria. Therefore, topical treatment with recombinant S25-3 endolysin can be a promising disease management procedure for staphylococcal impetigo by efficient bacteriolysis of S. aureus while improving the cutaneous bacterial microflora.

B cell-intrinsic MyD88 signaling controls IFN-γ-mediated early IgG2c class switching in mice in response to a particulate adjuvant

Adjuvants improve the potency of vaccines, but the modes of action (MOAs) of most adjuvants are largely unknown. TLR-dependent and -independent innate immune signaling through the adaptor molecule MyD88 has been shown to be pivotal to the effects of most adjuvants; however, MyD88's involvement in the TLR-independent MOAs of adjuvants is poorly understood. Here, using the T-dependent antigen NIPOVA and a unique particulate adjuvant called synthetic hemozoin (sHZ), we show that MyD88 is required for early GC formation and enhanced antibody class-switch recombination (CSR) in mice. Using cell-type-specific MyD88 KO mice, we found that IgG2c class switching, but not IgG1 class switching, was controlled by B cell-intrinsic MyD88 signaling. Notably, IFN-γ produced by various cells including T cells, NK cells, and dendritic cells was the primary cytokine for IgG2c CSR and B-cell intrinsic MyD88 is required for IFN-γ production. Moreover, IFN-γ receptor (IFNγR) deficiency abolished sHZ-induced IgG2c production, while recombinant IFN-γ administration successfully rescued IgG2c CSR impairment in mice lacking B-cell intrinsic MyD88. Together, our results show that B cell-intrinsic MyD88 signaling is involved in the MOA of certain particulate adjuvants and this may enhance our specific understanding of how adjuvants and vaccines work.

Th17 cells increase during maturation in peripheral blood of healthy dogs

Recent studies have indicated that T helper 17 (Th17) cells are involved in the pathogenesis of various inflammatory diseases in dogs. However, age-related changes in canine Th17 cells have not yet been investigated. In the present study, the proportion of Th17 cells was examined in the peripheral blood mononuclear cells (PBMCs) of healthy dogs at various ages: Group 1 (n = 16; less than 1 year of age), Group 2 (n = 25; 1-5 years), and Group 3 (n = 19; 6-9 years), using flow cytometry and an anti-human interleukin (IL)-17A monoclonal antibody that reacts with canine IL-17A. The proportion of circulating Th17 cells positively correlated with age. The age-related differences were observed in the proportion of Th17 cells among Group 1 (mean ± SD: 1.52 ± 1.18%), Group 2 (mean ± SD: 3.81 ± 1.94%) and Group 3 (mean ± SD: 7.49 ± 2.54%). Our results suggest that age-related changes in Th17 cells need to be considered in future research on Th17-related diseases in dogs.

Measurement for canine IgE using canine recombinant high affinity IgE receptor α chain (FcεRIα)

To detect allergen-specific IgE in dogs with allergic diseases, we developed a recombinant canine high affinity IgE receptor α chain (FcεRIα)-based IgE detection system. Using the recombinant protein of canine FcεRIα expressed by an Escherichia coli expression system, we could detect house dust mite (Dermatophagoides farinae) allergen-specific IgE in sera from dogs naturally and experimentally sensitized to this allergen with ELISA and western blotting. The IgE binding activity of recombinant canine FcεRIα on ELISA was impaired by heat treatment of these sera. The specificity of this recombinant canine FcεRIα-based IgE detection system was confirmed by inhibition assays with canine IgE. The recombinant canine FcεRIα-based IgE detection system established in this study offers an alternative tool to measure allergen-specific IgE in dogs.

The malarial metabolite hemozoin and its potential use as a vaccine adjuvant

Hemozoin, a bio-crystalline substance, is a hemin detoxification by-product of malaria parasites. The role of hemozoin crystals in host immune system modulation by malaria parasites, and how they interact with the immune system has been enigmatic. Here, we summarize recent progress in our understanding of how hemozoin might be interacting with the host immune system. In particular, the potential application of hemozoin crystals as an adjuvant may provide insights into the molecular mechanisms involved in immune responses to malarial infection and provide a rationale for the design of vaccines against malaria as well as other immunological disorders such as allergies.

Duodenogastric reflux induced by endoscopic submucosal dissection

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) may cause excessive duodenogastric reflux (DGR) in a similar manner to distal gastrectomy, particularly after antral resections. We aimed to examine the occurrence of DGR after ESD.

PATIENTS AND METHODS

Patients with gastric neoplasm for whom ESD was indicated were categorized according to lesion site: the antral group (lower [L] stomach, n = 46) and the nonantral group (upper or middle [U or M] stomach, n = 49). Endoscopy was performed before ESD, the day after ESD, and 3 months after ESD, and the fasting bile acid concentration (BAC) in the gastric juice was analyzed.

RESULTS

BAC values showed significant interaction between time point and group, although this association differed in the antral and nonantral groups. BACs on the day after ESD were higher in the antral group than in the nonantral group, but not the pre-ESD and 3 months post-ESD levels. In the antral group only, fasting BACs increased significantly the day after ESD and decreased to baseline levels 3 months post-ESD. There was also a correlation between BAC and lesion location in the antral subgroups, with significantly higher BACs found the day after ESD in patients with lesser curvature lesions.

CONCLUSIONS

ESD of lesions in the antral lesser curvature may lead to a transient early increase in DGR. However, ESD does not result in long-term DGR, a factor that is known to increase the risk of carcinogenesis following gastrectomy.

MAGE-A protein and MAGE-A10 gene expressions in liver metastasis in patients with stomach cancer

Tumour samples from 71 patients with stomach cancer, 41 patients with liver metastasis (group A) and 15 patients each in stages II–IV (group B) and stage I (group C) without liver metastasis were analysed. MAGE-A protein expression was evaluated by immunohistochemistry using a 6C1 monoclonal antibody and MAGE-A10 mRNA expression was detected by highly sensitive in situ hybridisation using a cRNA probe. Expressions of MAGE-A protein and MAGE-A10 mRNA in group A were detected in 65.9 and 80.5%, respectively. Both protein and gene showed significantly higher expression in group A than those in groups B (6.7, 26.7%) and C (0, 0%) (P=0.0003, P=<0.0001, respectively). MAGE-A10 mRNA expression in liver metastasis was found in eight (88.9%) out of nine patients. The concordant rate between MAGE-A family protein expression and MAGE-A10 mRNA expression in the primary sites was 81.7% (P<0.0001). MAGE-A10 gene expression was associated with reduced survival duration. The results of this study suggest that MAGE-A10 is a possible target in active immunotherapy for advanced stomach cancer.

Chemopreventive effect of celecoxib in gastric cancer

COX (cyclooxygenase) is one of the key enzymes involved in the synthesis of a variety of prostaglandins (PGs), some of which have been strongly linked to inflammation. One of its two well-known isoforms, COX-2, is an inducible enzyme whose induction and expression is dynamically regulated by growth factors, mitogens, and tumor promoters. Several animal and clinical studies have reported the chemopreventive effect of celecoxib, a selective COX-2 inhibitor; and in particular, a few studies have shown that celecoxib prevents the development of gastric cancer. Administration of celecoxib also showed increases in cardiovascular risk and disruption of renal physiology. Therefore, studies hoping to clarify how selective COX-2 inhibitors modulate gastric cancer must keep in mind that coxibs have also been linked to serious cardiovascular events and disruption of renal physiology.

Cloning of cDNA encoding canine endothelin receptors and their expressions in normal tissues

The receptors for endothelin (ET) family, ETA and ETB, were molecularly cloned and the expression of ETA and ETB as well as preproendothelin-1 (PPET-1, precursor of ET-1) was examined in normal canine tissues by RT-PCR. The entire open reading frames of the canine ETA and ETB were shown to encode 427 and 442 amino acid residues, respectively, showing from 87.4 to 97.3% sequence similarity to human, mouse, and rat counterparts. ETA and ETB mRNAs were ubiquitously expressed in a variety of canine tissues in this study and PPET-1 mRNA was detected in the tissues except for heart and liver. It was speculated that ET could play an important role in physiological events in most of the organs.

Monocyte chemoattractant protein 1 and macrophage cyclooxygenase 2 expression in colonic adenoma

BACKGROUND AND AIMS

Cyclooxygenase 2 (COX-2) expression in subepithelial macrophages of colorectal adenoma has been suggested as the first in a series of steps leading to colorectal tumorigenesis. We tested the hypothesis that chemokines released from human colorectal adenoma epithelium might be involved in COX-2 expression in macrophages of the lamina propria.

METHODS

Endoscopic samples of sporadic colorectal adenomas were tested by enzyme linked immunosorbent assay for chemokines involved in macrophage chemotaxis. Localisation of adenoma macrophage chemoattractant protein 1 (MCP-1) and COX-2 were determined by immunohistochemistry. The effects of MCP-1, in the presence or absence of celecoxib, on COX-2 expression, and prostaglandin (PG) E(2) and vascular endothelial growth factor (VEGF) release, were examined in human macrophages isolated from peripheral blood.

RESULTS

MCP-1 levels were markedly higher in adenoma with mild-moderate dysplasia (129.7 (19.9) pg/mg protein) and severe dysplasia (227.9 (35.4) pg/mg protein) than in normal colonic mucosa (55.8 (4.2) pg/mg protein). Other chemokine levels, macrophage inflammatory proteins (MIP)-1alpha and MIP-1beta, and the chemokine regulated on activation of normal T cell expressed and secreted (RANTES) did not vary significantly between adenoma and normal mucosa. MCP-1 levels in both adenoma and normal colonic mucosa increased significantly three hours after tissue cultivation in vitro. MCP-1 immunoreactivity was restricted to the adenoma epithelium, with no reactivity seen in adjacent normal epithelial cells. MCP-1 stimulated COX-2 expression and PGE(2) and VEGF release in human macrophages. Celecoxib, a selective COX-2 inhibitor, inhibited MCP-1-induced PGE(2) and VEGF release in macrophages. Addition of exogenous PGE(2) reversed this inhibitory effect on VEGF release, suggesting that MCP-1 in adenoma epithelial cells might be involved in COX-2 expression and subsequent macrophage activation.

CONCLUSIONS

MCP-1 in colorectal adenoma epithelial cells might be involved in macrophage migration and COX-2 expression, leading to the subsequent development of colonic adenoma.

Preventive therapy for non-steroidal anti-inflammatory drug-induced ulcers in Japanese patients with rheumatoid arthritis: the current situation and a prospective controlled-study of the preventive effects of lansoprazole or famotidine

BACKGROUND

There is a lack of evidence for the efficacy of preventive medications for peptic ulcers (PUs) among long-term users of non-steroidal anti-inflammatory drugs (NSAIDs) in Japan.

AIM

To estimate the preventive effect by normal dose, not high-dose histamine-H2 receptor antagonists (H2RA) for NSAID-induced ulcers.

METHODS

We designed two different studies to assess the efficacy of anti-ulcer agents in rheumatoid arthritis (RA) in patients treated over a long term with NSAIDs. An investigative survey divided patients into those not taking anti-ulcer agents (non-medication group); those taking mucosal protective agents (mucosal protectant group), H2RA (H2RA group), proton pump inhibitors (PPI group), or a prostaglandin E1 analog (PG) (PG group). The second study compared prospectively the preventive effects of either famotidine 20 mg bd (famotidine group) or lansoprazole 15 mg daily (lansoprazole group) in patients with PU scars.

RESULTS

The prevalence of PU in the H2RA group was significantly lower compared to the mucosal protectant group (P < 0.05), and the mucosal protectant group was not significantly different to the non-medication group. The prospective study revealed that the PU onset rate of the famotidine group was 8% (1/13), and lansoprazole group was 15% (2/13), indicating no significant differences between the two.

CONCLUSIONS

In Japan, normal-dose H2RA is expected to be a new PU preventive treatment strategy in patients requiring long-term NSAID therapy.

Implications of corpus gastritis, atrophy and cyclooxygenase in the development of gastric erosions after curing Helicobacter pylori infection

BACKGROUND

Helicobacter pylori eradication decreases recurrence of peptic ulcers with marked improvement in histological inflammation, but gastric mucosal injuries may be developed even after eradication.

PURPOSE

To investigate the mechanisms responsible for the development of gastric erosions after eradication, we analysed the relationship between clinicopathological risk factors and the occurrence of gastric erosion after curing H. pylori infection.

PATIENTS

Sixty patients underwent endoscopy before, and 3, 6 and 12 months after the completion of H. pylori eradication.

METHODS

Risk factors associated with the development of gastric erosions after eradication were assessed by multivariate analysis, and cyclooxygenase-1 and -2 immunoreactivity was histologically examined in the gastric mucosa before and after eradication.

RESULTS

The cumulative prevalence of gastric erosions after H. pylori eradication was 38.3% within 1 year. Using multivariate analysis, corpus gastritis scores (inflammation score+activity score), corpus atrophy scores and an age of more than 50 years were found to be independent factors associated with the development of gastric erosion after eradication with odds ratios of 7.39, 0.13 and 5.00, respectively. Cyclooxygenase-2 immunoreactivity of the corpus was decreased for the non-erosion group after eradication, but not for the erosion group.

CONCLUSIONS

Severe gastritis or less severe atrophy in oxyntic glands but not in pyloric glands before eradication may be involved in the development of gastric erosions after curing H. pylori infection.

Production of a monoclonal antibody to canine thymus and activation-regulated chemokine (TARC) and detection of TARC in lesional skin from dogs with atopic dermatitis

A monoclonal antibody to canine thymus and activation-regulated chemokine (TARC/CCL17) was developed to examine the association of TARC with the immunopathogenesis of canine atopic dermatitis (AD). Recombinant canine TARC was prepared using an E. coli expression system. Results of transwell chemotaxis assay demonstrated that the recombinant canine TARC showed chemotactic activity for canine lymphoid cells expressing CC chemokine receptor 4 (CCR4). Mice were then immunized with the recombinant canine TARC to obtain monoclonal antibodies. Among the monoclonal antibodies thereby obtained, one monoclonal antibody (CTA-1) was found to react with both recombinant and authentic canine TARC in ELISA and flowcytometric assays, respectively. Immunohistochemical analysis using the monoclonal antibody CTA-1 demonstrated that keratinocytes were major TARC producing cells in lesional skin of dogs with AD.

Identification of peptides containing T-cell epitopes of Japanese cedar (Cryptomeria japonica) pollen allergen (Cry j 1) in dogs

Japanese cedar (Cryptomeria japonica, CJ) pollen has been known to cause atopic dermatitis in dogs in Japan. However, since the mechanism of the CJ antigen recognition is not well understood in dogs, it is difficult to develop effective immunotherapy for atopic dermatitis caused by sensitization to CJ pollen. In order to aim at development of a peptide immunotherapy, we tried to identify T-cell epitopes of a major allergen of CJ pollen, Cry j 1, in dogs sensitive to CJ pollen allergen. Peripheral blood mononuclear cells (PBMCs) obtained from 22 dogs experimentally sensitized to CJ pollen allergen and 5 atopic dogs sensitive to CJ pollen allergen were used for mapping of T-cell epitopes of Cry j 1 using 35 kinds of synthesized overlapping peptides of Cry j 1. Reactive peptides were identified based on the results of blastogenic responses of PBMCs against the peptides when the stimulation indices were beyond 2.0. Three reactive peptides were identical in a relatively high population of experimental dogs, which were Nos. 8 (p71-90) (41%), 10 (p91-110) (50%), and 11 (p101-120) (41%). It was considered that these synthesized peptides should contain T-cell epitopes of Cry j 1 in the dogs. However, there were no reactive peptides identical among the five atopic dogs spontaneously sensitive to CJ pollen. The population of dogs experimentally sensitized to CJ pollen antigen will be used in order to investigate effects of a peptide immunotherapy using the reactive peptides. The results in atopic dogs sensitive to CJ pollen antigen will also provide useful information on necessity to develop a tailor-made immunotherapy using reactive peptides in each dog.

CTLA-4 recombinant protein genetically fused to canine Fcepsilon receptor Ialpha enhances allergen specific lymphocyte responses in experimentally sensitized dogs

Vaccination with a recombinant antigen fused to a targeting molecule is a potential strategy for inducing efficient immune responses. For the therapeutic purpose of allergic diseases in dogs, a DNA construct which expresses recombinant fusion protein with two functional domains, cytotoxic T lymphocyte antigen (CTLA-4) and Fcepsilon receptor Ialpha, was developed to bridge antigen-presenting cells and IgE-allergen complex. The recombinant fusion protein expressed by the DNA construct was demonstrated to retain the ability to bind monocytes in PBMC and dog IgE, respectively. Additionally, the recombinant protein induced enhancement of allergen-induced lymphoproliferation in experimentally sensitized dogs under conditions of suboptimal allergen stimulation. These results indicated that the DNA construct could enhance allergen-induced immune responses in vivo, implying its usefulness for perspective application in immunotherapy in dogs.

Monocyte chemoattractant protein 1 (MCP-1) released from Helicobacter pylori stimulated gastric epithelial cells induces cyclooxygenase 2 expression and activation in T cells

BACKGROUND

and aims: To clarify the interaction between gastric epithelial and mucosal T cells, we examined the role of cytokines released from epithelial cells in response to Helicobacter pylori water extract protein (HPWEP) in regulating T cell cyclooxygenase 2 (COX-2) expression and activation.

METHODS

Media from MKN-28 cells incubated with HPWEP for 48 hours were added to Jurkat T cells and human peripheral T cells. C-C and CXC chemokine concentrations in MKN-28 cell media, and COX-2 expression, interferon gamma (IFN-gamma), and interleukin (IL)-4 secretions in T cells were determined by western blot analysis and ELISA methods. Distributions of COX-2 positive T cells and monocyte chemoattractant protein 1 (MCP-1) in tissue specimens with H pylori associated gastritis were determined as single or double labelling by immunohistochemistry.

RESULTS

MCP-1, IL-7, IL-8, and RANTES were detected in media from MKN-28 cells incubated with HPWEP. Media as a whole, and MCP-1 alone, stimulated COX-2 expression and peripheral T cell proliferation. Anti-MCP-1 antibody inhibited media stimulated COX-2 mRNA expression in Jurkat T cells. Media stimulated IFN-gamma but not IL-4 secretion from peripheral T cells, while MCP-1 stimulated IL-4 but not IFN-gamma secretion. Both stimulated cytokine release, and peripheral T cell proliferation was partially inhibited by NS-398, a specific COX-2 inhibitor. In mucosa with gastritis, COX-2 was expressed in T cells and MCP-1 was localised mainly in epithelial and mononuclear cells. MCP-1 levels and the intensity of COX-2 expression in tissue samples were closely related.

CONCLUSIONS

Cytokines such as MCP-1, released from gastric epithelial cells in response to HPWEP, seem to modulate T cell immune responses, at least in part via COX-2 expression.

Differential expression of secreted frizzled-related protein 4 in decidual cells during pregnancy

During pregnancy, the uterus shows marked morphological and physiological changes under the regulation of ovarian steroid. To elucidate the molecular cues of these changes, we tried to identify the transcripts differentially expressed in the pregnant rat uterus by using the suppression subtractive hybridization method. Seven independent clones were isolated and one of the up-regulated genes was secreted frizzled-related protein 4 (sFRP4). sFRP4 contains a Wnt-binding domain and belongs to the secreted frizzled protein family whose members are assumed to function as modulators of the Wnt signal. The expression level of sFRP4 mRNA reached a peak in the pregnant uterus on day 12, when uterine decidualization was almost complete in the rat. In situ hybridization histochemistry revealed that sFRP4 transcripts were observed in the decidual cells. In addition, proliferating cell nuclear antigen (PCNA)-positive cells were shown to be overlapped in decidua, suggesting that sFRP4 mRNA expression was accompanied by the late phase of decidual cell proliferation. Moreover, sFRP4 and estrogen receptor-alpha transcripts were co-localized. Furthermore, we analyzed the regulation of sFRP4 by estrogen using 17 beta-estradiol-treated ovariectomized rats. sFRP4 mRNA was detected in the uterus at 48 h after estrogen treatment, especially in endometrial stroma where PCNA-positive cells were also observed. The results in this study led us to the notion that sFRP4 mRNA may be up-regulated after estrogen treatment in the late phase of uterine cell proliferation.

Inhibition of Helicobacter pylori-induced cyclo-oxygenase-2 aggravates NSAID-caused gastric damage in Mongolian gerbils

BACKGROUND

The effect of Helicobacter pylori infection on non-steroidal anti-inflammatory drug-induced gastric mucosal injury is controversial.

AIM

To examine the effect of the interaction between H. pylori and non-steroidal anti-inflammatory drugs on gastric mucosal injury.

METHODS

Mongolian gerbils infected with H. pylori were treated with indometacin at 8 mg/kg for 2 days or 7 days. Mucosal damage was assessed by macroscopic and histological examination, and myeloperoxidase activity was measured as an index of neutrophil infiltration. The expression levels of cyclo-oxygenase proteins were determined by Western blot analysis and cyclo-oxygenase activity.

RESULTS

A 2-day course of indometacin did not cause an increase in gastric damage in H. pylori-infected Mongolian gerbils compared to uninfected gerbils, while a 7-day course of indometacin caused additive gastric damage in H. pylori-infected animals. H. pylori infection induced cyclo-oxygenase-2 expression in the stomach. Treatment with indometacin for 2 days did not significantly affect cyclo-oxygenase activity in H. pylori-infected animals, while treatment for 7 days inhibited both cyclo-oxygenase-1 and cyclo-oxygenase-2 activities. Pre-treatment with a selective cyclo-oxygenase-2 inhibitor aggravated mucosal injury in H. pylori-infected animals treated or not treated with indometacin for 2 days.

CONCLUSIONS

Our results suggest that cyclo-oxygenase-2 protein induced by H. pylori infection may be involved in the defence of the gastric mucosa against damage caused by non-steroidal anti-inflammatory drugs. Therefore, inhibition of cyclo-oxygenase-2 activity may enhance non-steroidal anti-inflammatory drug-caused gastric damage in H. pylori-infected animals.

Effect of acid suppression therapy on development of gastric erosions after cure of Helicobacter pylori infection

BACKGROUND

Helicobacter pylori eradication markedly improves histological inflammation and decreases peptic ulcer recurrence, but little is known about the subsequent development of gastric mucosal injury.

AIM

To investigate whether acid suppression treatment after eradication influences the development of gastric erosions.

METHODS

Eighty-one patients (gastritis or peptic ulcer) after successful H. pylori eradication were divided into two groups: 40 received an H2-blocker for 6 months (H2-blocker-positive) and 41 received no treatment (H2-blocker-negative). Endoscopy was performed before, and at 3 and 6 months after completion of eradication.

RESULTS

Cumulative prevalence of gastric erosions in the H2-blocker-positive group was significantly lower than in the H2-blocker-negative group, 25% vs. 42%, respectively. In the H2-blocker-negative group but not the H2-blocker-positive group, the cumulative prevalence of gastric erosions after eradication was higher in patients with less severe corpus atrophy or more severe corpus gastritis.

CONCLUSIONS

Development of gastric erosions after H. pylori eradication may be controlled by acid suppression treatment. Less severe atrophy or more severe gastritis in oxyntic glands before eradication may be involved in the development of gastric erosions. These results support the idea that recovery of acid secretion may be one of factors for development of gastric mucosal erosions after successful eradication.

Dickkopf1 is required for embryonic head induction and limb morphogenesis in the mouse

Dickkopf1 (Dkk1) is a secreted protein that acts as a Wnt inhibitor and, together with BMP inhibitors, is able to induce the formation of ectopic heads in Xenopus. Here, we show that Dkk1 null mutant embryos lack head structures anterior of the midbrain. Analysis of chimeric embryos implicates the requirement of Dkk1 in anterior axial mesendoderm but not in anterior visceral endoderm for head induction. In addition, mutant embryos show duplications and fusions of limb digits. Characterization of the limb phenotype strongly suggests a role for Dkk1 both in cell proliferation and in programmed cell death. Our data provide direct genetic evidence for the requirement of secreted Wnt antagonists during embryonic patterning and implicate Dkk1 as an essential inducer during anterior specification as well as a regulator during distal limb patterning.

Aging increases, and duodenal ulcer reduces the risk for intestinal metaplasia of the gastric corpus in Japanese patients with dyspepsia

BACKGROUND AND AIMS

The classification of gastritis by using the revised Sydney system suggests that there are two types of Helicobacter pylori-related gastritis. The aim of the present study was to examine the risk factors that might be involved in the presence of either atrophic gastritis or intestinal metaplasia of the gastric corpus of Japanese patients.

METHODS

Biopsy samples were obtained from the gastric corpus in 154 patients with dyspepsia, and the degree of atrophy or intestinal metaplasia was determined histologically. The correlation between several variables and presence of atrophy or intestinal metaplasia was evaluated by using multivariate analysis.

RESULTS

Among the 11 variables, which included age, peptic ulcer diseases and H. pylori infection, H. pylori infection was the major risk factor associated with the presence of atrophic gastritis or intestinal metaplasia of the gastric corpus. In contrast, duodenal ulcer (DU) disease reduced the risk of contracting both conditions. Age was an independent risk factor only for intestinal metaplasia of the gastric corpus. When 128 H. pylori-positive subjects were analyzed, DU and age were similarly associated with the presence of both conditions.

CONCLUSIONS

These results suggest that DU reduces the risk for contracting atrophic gastritis and intestinal metaplasia, and age is an independent risk factor for intestinal metaplasia of the gastric corpus in dyspeptic Japanese patients.

Evidence that members of the Cut/Cux/CDP family may be involved in AER positioning and polarizing activity during chick limb development

In vertebrates, the apical ectodermal ridge (AER) is a specialized epithelium localized at the dorsoventral boundary of the limb bud that regulates limb outgrowth. In Drosophila, the wing margin is also a specialized region located at the dorsoventral frontier of the wing imaginal disc. The wingless and Notch pathways have been implicated in positioning both the wing margin and the AER. One of the nuclear effectors of the Notch signal in the wing margin is the transcription factor cut. Here we report the identification of two chick homologues of the Cut/Cux/CDP family that are expressed in the developing limb bud. Chick cux1 is expressed in the ectoderm outside the AER, as well as around ridge-like structures induced by (β)-catenin, a downstream target of the Wnt pathway. cux1 overexpression in the chick limb results in scalloping of the AER and limb truncations, suggesting that Cux1 may have a role in limiting the position of the AER by preventing the ectodermal cells around it from differentiating into AER cells. The second molecule of the Cut family identified in this study, cux2, is expressed in the pre-limb lateral plate mesoderm, posterior limb bud and flank mesenchyme, a pattern reminiscent of the distribution of polarizing activity. The polarizing activity is determined by the ability of a certain region to induce digit duplications when grafted into the anterior margin of a host limb bud. Several manipulations of the chick limb bud show that cux2 expression is regulated by retinoic acid, Sonic hedgehog and the posterior AER. These results suggest that Cux2 may have a role in generating or mediating polarizing activity. Taking into account the probable involvement of Cut/Cux/CDP molecules in cell cycle regulation and differentiation, our results raise the hypothesis that chick Cux1 and Cux2 may act by modulating proliferation versus differentiation in the limb ectoderm and polarizing activity regions, respectively.

Localisation of cyclooxygenase 1 and cyclooxygenase 2 in Helicobacter pylori related gastritis and gastric ulcer tissues in humans

BACKGROUND

Prostaglandin endoperoxide synthase/cyclooxygenase (COX) is the key enzyme in gastric mucosal protection and repair but its cellular localisation in the human stomach is still unclear.

AIMS

To investigate immunohistochemically the cellular distribution of COX-1 and COX-2 proteins in the human stomach with or without gastritis or ulceration.

PATIENTS AND METHODS

Tissues were obtained by surgical resection of gastric ulcers associated with perforation (n = 9) or by biopsy from Helicobacter pylori positive patients with gastric ulcers (n = 45) and H pylori negative healthy subjects (n = 15). COX expression was detected by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR), western blotting, and light and electron microscopic immunohistochemistry.

RESULTS

COX-2 mRNA and protein were detected in gastric ulcer tissues but not in intact gastric mucosa. COX-1 mRNA and protein were detected in the intact mucosa. COX-2 immunostaining was exclusively localised in macrophages and fibroblasts between necrotic and granulation tissues of the ulcer bed. The percentage of COX-2 expressing cells was significantly higher in open than in closed ulcers, and in gastritis than in gastric mucosa without H pylori infection. COX-1 immunoreactivity localised in lamina propria mesenchymal cells was similar in various stages of ulcer disease and in intact gastric mucosa. Electron microscopic immunohistochemistry revealed both COX-1 and COX-2 on the luminal surfaces of the endoplasmic reticulum and nuclear envelope of macrophages and fibroblasts.

CONCLUSIONS

Our results showed that COX-2 protein was induced in macrophages and fibroblasts in gastric ulcers and H pylori related gastritis, suggesting its involvement in the tissue repair process.

Induction of cyclooxygenase-2 in mesothelial cells in peritonitis caused by perforated ulcers--an immunohistochemical study in humans

BACKGROUND

Increasing evidence suggests that mesothelial cells contribute to the control of inflammation in the peritoneal cavity by secreting prostaglandins. A study has shown that cyclooxygenase (COX)-2 knockout mice die partly as a result of peritonitis.

AIM

To investigate the expression and location of COX in peritonitis associated with peptic ulcer perforation.

METHODS

Gastric and duodenal tissues were collected intraoperatively from nine and four patients, respectively, and immunohistochemical staining for COX-1 and COX-2 was performed.

RESULTS

Histologically, all patients had severe peritonitis around the perforation sites, into which many inflammatory cells and fibroblasts had infiltrated, and reactive mesothelial cells exhibited hyperplastic change. The COX-1 protein was not detected, whereas COX-2 was abundant in reactive mesothelial cells near the perforation site and disappeared away from the site. Macrophages and fibroblasts around the perforation site also revealed immunostaining for COX-2.

CONCLUSIONS

Our results showed that COX-2 protein is induced in mesothelial cells, as well as in macrophages and fibroblasts, in inflamed peritoneal tissues associated with peptic ulcer perforation, suggesting involvement of COX-2 in tissue repair.

Control of vertebrate limb outgrowth by the proximal factor Meis2 and distal antagonism of BMPs by Gremlin

The mechanisms controlling growth and patterning along the proximal-distal axis of the vertebrate limb are yet to be understood. We show that restriction of expression of the homeobox gene Meis2 to proximal regions of the limb bud is essential for limb development, since ectopic Meis2 severely disrupts limb outgrowth. We also uncover an antagonistic relationship between the secreted factors Gremlin and BMPs required to maintain the Shh/FGF loop that regulates distal outgrowth. These proximal and distal factors have coordinated activities: Meis2 can repress distal genes, and Bmps and Hoxd genes restrict Meis2 expression to the proximal limb bud. Moreover, combinations of BMPs and AER factors are sufficient to distalize proximal limb cells. Our results unveil a novel set of proximal-distal regulatory interactions that establish and maintain outgrowth of the vertebrate limb.

Multiple left-right asymmetry defects in Shh(-/-) mutant mice unveil a convergence of the shh and retinoic acid pathways in the control of Lefty-1

Asymmetric expression of Sonic hedgehog (Shh) in Hensen's node of the chicken embryo plays a key role in the genetic cascade that controls left-right asymmetry, but its involvement in left-right specification in other vertebrates remains unclear. We show that mouse embryos lacking Shh display a variety of laterality defects, including pulmonary left isomerism, alterations of heart looping, and randomization of axial turning. Expression of the left-specific gene Lefty-1 is absent in Shh(-/-) embryos, suggesting that the observed laterality defects could be the result of the lack of Lefty-1. We also demonstrate that retinoic acid (RA) controls Lefty-1 expression in a pathway downstream or parallel to Shh. Further, we provide evidence that RA controls left-right development across vertebrate species. Thus, the roles of Shh and RA in left-right specification indeed are conserved among vertebrates, and the Shh and RA pathways converge in the control of Lefty-1.

A model for CD8+ CTL tumor immunosurveillance and regulation of tumor escape by CD4 T cells through an effect on quality of CTL

Understanding immune mechanisms influencing cancer regression, recurrence, and metastasis may be critical to developing effective immunotherapy. Using a tumor expressing HIV gp160 as a model viral tumor Ag, we found a growth-regression-recurrence pattern, and used this to investigate mechanisms of immunosurveillance. Regression was dependent on CD8 T cells, and recurrent tumors were resistant to CTL, had substantially reduced expression of epitope mRNA, but retained the gp160 gene, MHC, and processing apparatus. Increasing CTL numbers by advance priming with vaccinia virus expressing gp160 prevented only the initial tumor growth but not the later appearance of escape variants. Unexpectedly, CD4 cell depletion protected mice from tumor recurrence, whereas IL-4 knockout mice, deficient in Th2 cells, did not show this protection, and IFN-gamma knockout mice were more susceptible. Purified CD8 T cells from CD4-depleted mice following tumor regression had more IFN-gamma mRNA and lysed tumor cells without stimulation ex vivo, in contrast to CD4-intact mice. Thus, the quality as well as quantity of CD8+ CTL determines the completeness of immunosurveillance and is controlled by CD4 T cells but not solely Th2 cytokines. This model of immunosurveillance may indicate ways to enhance the efficacy of surveillance and improve immunotherapy.

The T-box genes Tbx4 and Tbx5 regulate limb outgrowth and identity

During embryonic development, initially similar fields can develop into distinct structures, such as the vertebrate fore- and hindlimbs. Although considerable progress has been made in our understanding of the genetic control underlying the establishment of the different limb axes, the molecular cues that specify the differential development of the fore- and hindlimbs are unknown. Possible candidates for genes determining limb identity are Pitx1, a gene whose transcripts are detected in the early hind- but not forelimb bud, and two members of the T-box (Tbx) gene family, Tbx4 and Tbx5, which are specifically expressed in the hindlimb and forelimb buds, respectively. Here we show that Tbx4 and Tbx5 are essential regulators of limb outgrowth whose roles seem to be tightly linked to the activity of three signalling proteins that are required for limb outgrowth and patterning: fibroblast growth factor (FGF), bone morphogenetic protein (BMP) and Wnt. In addition, we provide evidence that Tbx4 and Tbx5 are involved in controlling limb identity. Our findings provide insight into how similar developmental fields can evolve into homologous but distinct structures.

Spatially and temporally-restricted expression of two T-box genes during zebrafish embryogenesis

T-box genes are conserved in all animal species. We have identified two members of the T-box gene family from the zebrafish, Danio rerio. Zf-tbr1 and zf-tbx3 share high amino acid identity with human, murine, chick and Xenopus orthologs and are expressed in specific regions during zebrafish development.

Pitx2 determines left-right asymmetry of internal organs in vertebrates

The handedness of visceral organs is conserved among vertebrates and is regulated by asymmetric signals relayed by molecules such as Shh, Nodal and activin. The gene Pitx2 is expressed in the left lateral plate mesoderm and, subsequently, in the left heart and gut of mouse, chick and Xenopus embryos. Misexpression of Shh and Nodal induces Pitx2 expression, whereas inhibition of activin signalling blocks it. Misexpression of Pitx2 alters the relative position of organs and the direction of body rotation in chick and Xenopus embryos. Changes in Pitx2 expression are evident in mouse mutants with laterality defects. Thus, Pitx2 seems to serve as a critical downstream transcription target that mediates left-right asymmetry in vertebrates.

Tbx genes and limb identity in chick embryo development

Tbx-2, Tbx-3, Tbx-4 and Tbx-5 chick genes have been isolated and, like the mouse homologues, are expressed in the limb regions. Tbx-2 and Tbx-3 are expressed in anterior and posterior domains in wings and legs, as well as throughout the flank. Of particular interest, however, are Tbx-5, which is expressed in wing and flank but not leg, and Tbx-4, which is expressed very strongly in leg but not wing. Grafts of leg tissue to wing and wing tissue to leg give rise to toe-like or wing-like digits in wing and leg respectively. Expression of Tbx-4 is stable when leg tissue is grafted to wing, and Tbx-5 expression is stable when wing tissue is grafted to leg. Induction of either extra wings or legs from the flank by applying FGF-2 in different positions alters the expression of Tbx-4 and Tbx-5 in such a way that suggests that the amount of Tbx-4 that is expressed in the limb determines the type that will form. The ectopic limb always displays a limb-like Tbx-3 expression. Thus Tbx-4 and Tbx-5 are strong candidates for encoding ‘wingness’ and ‘legness’.

Immune activation in cervical neoplasia: cross-sectional association between plasma soluble interleukin 2 receptor levels and disease

In a previous study (Tsukui et al., Cancer Res., 56: 3967-3974, 1996), we observed an inverse association between degree of cervical neoplasia and interleukin (IL) 2 production by peripheral blood mononuclear cells in response to human papillomavirus (HPV) 16 E6 and E7 peptides in vitro. This suggested that a Th1-mediated cellular immune response might be important in host immunological control of HPV infection and that a lack of such a response might predispose to progression of cervical disease. To follow up on these findings, we have conducted a cross-sectional study of women with various degrees of cervical neoplasia to investigate the association between overall immune activation and cervical disease. A total of 235 women were recruited into our study; 120 of these women were participants in our previous study in which IL-2 production in response to HPV-16-specific peptides was measured. The study population included 34 women with invasive cancer, 62 women with high-grade squamous intraepithelial lesions (HSILs), and 105 women with low-grade squamous intraepithelial lesions (LSILs). In addition, 34 cytologically normal women with no past history of squamous intraepithelial lesions despite confirmed HPV-16 infection in the 5 years preceding the study were selected as controls. As our measure of overall immune activation, serum samples obtained from study participants were tested for soluble IL-2 receptor (sIL-2R) level using an ELISA method. The mean sIL-2R levels were found to increase with increasing disease severity (Ptrend = 0.0002). Among cytologically normal, HPV-exposed women, the mean receptor level in serum was 465.8 units/ml compared to 467.6 units/ml among LSIL subjects, 514.9 units/ml among HSIL subjects, and 695.5 units/ml among women with invasive cervical cancer. Similarly, the proportion of women with elevated sIL-2R levels (defined as > or = 450 units/ml) increased with increasing disease severity from 35.2% among normal study subjects to 70.6% among cancer patients (Ptrend = 0.003). Among the subgroup of subjects for whom in vitro IL-2 production in response to HPV-16-specific peptides was measured, we examined the association between in vitro IL-2 production and serum levels of sIL-2R. sIL-2R levels were higher, on average, among those women who were positive in our IL-2 production assay compared to those who were negative, but the differences did not reach statistical significance (P > 0.05). We also observed a trend of increasing sIL-2R level with increasing disease severity both in women who were positive and in women who were negative for our IL-2 production assay, but the trend was only significant among those who were negative for IL-2 production (Ptrend = 0.01). Results from our studies suggest that although the immune system of women with cervical neoplasia is nonspecifically activated as disease severity increases, the ability of those women with HSILs or cancer to mount a Th1-mediated immune response to HPV peptides appears to decrease compared to women with LSILs or normal women infected with HPV. Increased overall activation along with decreased Th1 immune response among women with increasing cervical disease severity might be explained by an increased Th2-mediated immune response, a response that we hypothesize is ineffective in controlling the viral infection and its early cytological manifestations. Future studies should directly assess Th2-mediated responses to confirm this hypothesis. Also, future efforts should be aimed at determining whether the associations observed are causally related to disease progression or an effect of the disease.

Interleukin 2 production in vitro by peripheral lymphocytes in response to human papillomavirus-derived peptides: correlation with cervical pathology

Human papillomavirus (HPV) is believed to be the major cause of cervical cancer. To investigate whether a cellular immune response, especially a T helper type 1 response, is related to the natural defense against HPV-related cervical lesions, the interleukin 2 response of peripheral blood lymphocytes in vitro to overlapping peptides from HPV-16 E6 and E7 oncoproteins was compared with the degree of cervical cytological abnormality among 140 women in a cross-sectional study. We compared 66 women diagnosed with low-grade squamous intraepithelial lesions (LSIL), 21 with high-grade squamous intraepithelial lesions (HSIL), and 28 with invasive cervical cancer with 25 women who were cytologically normal but previously HPV-16 DNA positive. The fraction showing strong interleukin 2 production against HPV-16 peptides was greatest among cytologically normal women (35%) and declined with increasing disease severity [LSIL] (20%), HSIL, (17%), and cancer patients (7%); X2 test P for the trend = 0.02], whereas the responses against a recall influenza antigen were not significantly different among groups. Our finding suggests that a T helper lymphocyte type 1 response to HPV antigens is associated with disease status. This result may reflect a targeted effect of the disease on immune function or a protective effect of the immune response against disease progression.