Degree Of Lymphocytic Infiltration Research Articles

HER-2/neu status and tumor morphology of invasive breast carcinomas in Ashkenazi women with known BRCA1 mutation status in the Ontario Familial Breast Cancer Registry.

The prevalence of BRCA1 germline mutations is greater in the Ashkenazi Jewish population than in the general North American population. The Ontario Familial Breast Cancer Registry collects clinical and family history data in familial breast carcinoma cases, and unselected Ashkenazi breast carcinomas, and acts as a tumor tissue repository. Using this resource, we examined the tumor morphology, hormone receptor status, and HER-2/neu protein overexpression in Canadian Ashkenazi breast carcinoma patients whose germline BRCA1 mutation status is known. Thirty-eight tumors from 32 BRCA1 carriers and 354 tumors from 334 noncarriers were analyzed. The tumors in BRCA1 mutation carriers were more likely to be high grade (P < 0.0001) and estrogen receptor negative (P < 0.004). There was an increased frequency of typical medullary carcinomas in mutation carriers when all tumors were analyzed. However, this difference did not remain statistically significant when only the first tumor diagnosed in each patient was included in the analysis. There was no difference in HER-2/neu protein overexpression between the two groups overall (P = 0.07). However, when the analysis was restricted to Grade III tumors, there were significantly fewer HER-2/neu-positive tumors in the mutation carriers versus noncarriers (3.1% vs. 21.5%, P = 0.012). No significant differences were found in the incidence of lymph node status, progesterone receptor status, lymphatic vessel invasion, degree of lymphocytic infiltration, or in the presence of ductal carcinoma in situ associated with the invasive tumors. Increasing awareness of the morphologic and immunophenotypic features more commonly found in BRCA1-associated breast carcinomas may lead to a wider use of these characteristics in genetic screening programs and provide further clues to their pathogenesis.

The prognostic significance of the tumour infiltrating lymphocyte count in stage I testicular seminoma managed by surveillance

The degree of lymphocytic infiltration is a significant determinant of outcome for a variety of malignancies, but its role in seminoma is unknown. 150 men with stage I testicular seminoma presenting between 1981 and 1993 were managed by surveillance following orchidectomy. The presence of tumour infiltrating lymphocytes (TILs) in each case was classified as high, intermediate or low. At a median follow-up of 9.4 years, 30 of the 150 men developed recurrent seminoma. On univariate analysis, the risk of relapse was associated with age ⩽33 years (P=0.002), tumour diameter >6 cm (P=0.03), lymphatic or vascular invasion (P=0.04), tumour invasion of rete testis (P=0.05), and lower TIL count (P=0.02). On multivariate analysis, statistically significant predictors of risk of relapse were age ⩽33 years (hazard ratio (HR) 4.6 (95% confidence intervals (CI): 1.7–12.2)) and tumour diameter >6 cm (HR 2.8 (CI: 1.2–6.5)). Lower TIL count was of borderline statistical significance (HR 1.8 (CI: 0.96–3.44)). The functional role of the lymphocytic infiltrate in testicular seminoma warrants further study.

Dietary mistletoe lectin supplementation and reduced growth of a murine non-Hodgkin lymphoma.

The growth of a murine non-Hodgkin lymphoma (NHL) tumour has been shown to be reduced by incorporating mistletoe lectin (ML-1) into the diet. The morphological characteristics of NHL tumours in mice fed ML-1-supplemented diets were different from those in LA (control)-fed mice. The degree of mitotic activity was lower and nuclear area reduced. The degree of lymphocyte infiltration was increased in tumours from ML-1 fed mice and this was accompanied by a high incidence of apoptotic bodies. Visual observation of NHL tumours from individuals fed ML-1 diet showed a poorly developed blood supply in contrast to control-fed mice. A major reduction in number of blood capillaries in NHL tumours was confirmed by microscopic evaluation of tumour sections. The results suggested an anti-angiogenic response in ML-1-fed mice. The feeding of ML-1 compared to control diet thus provided several identifiable changes in the morphology of NHL tumours which were consistent with the observed reduction in tumour weight. There was no longer histological evidence of viable tumour in 25% mice fed the ML-1 diet for 11 days. Morphological studies of the small bowel indicated (a) that the lectin induces hyperplasia, and (b) that the lectin binds avidly to lymphoid tissue of Peyer's patches. There was evidence of limited endocytosis of the lectin. An experiment where ML-3 was added to the diet of mice three days after inoculation of tumour cells showed that the lectin was able to slow down further growth of an established tumour. The results show that ML lectins induce powerful anti-cancer effects when provided by the oral route.

Tumor angiogenesis in lymph node-negative rectal cancer: correlation with clinicopathological parameters and prognosis.

Intratumoral microvessel density (MVD) could be used as a prognostic factor in colorectal cancer. We retrospectively analyzed the value of microvessel count in predicting the clinical outcome of stage I and II (Dukes A and B) rectal cancer patients. Eighty-four patients who had undergone curative resection of lymph node-negative rectal cancer were included. Tumor type and differentiation, the depth of local invasion, venous invasion, the character of the invasive margin, and the degree of lymphocytic infiltration were evaluated for each tumor specimen. Immunohistochemical staining for the CD31 endothelial antigen was performed to highlight the microvessels. The median value of MVD was 45 microvessels. Low MVD (microvessels < or = 45) was observed in 41 patients (48.8%), and high MVD (>45) was found in 43 (51.2%). The presence of conspicuous lymphocytic infiltration was significantly associated with increased vessel density. With uni- and multivariate survival analysis MVD did not show any prognostic significance. The character of the invasive margin was the only parameter with independent prognostic value. MVD does not seem to provide any additional prognostic information when compared with standard histopathological parameters in lymph node-negative rectal cancer. It is likely that the strong association between MVD and the presence of conspicuous lymphocytic infiltration may interfere with its predictive value.

One-year prophylactic treatment of euthyroid Hashimoto's thyroiditis patients with levothyroxine: is there a benefit?

Studies in animal models of spontaneous Hashimoto's autoimmune thyroiditis (HT) show that prophylactic treatment with levothyroxine (LT4) can reduce incidence and degree of lymphocytic infiltration in HT. The aim of the present study was to clarify whether there is a benefit of prophylactic treatment with LT4 in patients with euthyroid HT with respect to the progression of the autoimmune process. Twenty-one patients with euthyroid HT were checked for thyroid function (thyrotropin [TSH], free triiodothyronine [FT3], free thyroxine [FT4]), thyroid volume, antibodies (thyroglobulin [Tg-Ab], thyroid peroxidase [TPO-Ab]), and lymphocyte subsets. Peripheral (PBL) and thyroid-derived lymphocytes (TL) were analyzed by triple color flow cytometry. One-half of the patients with euthyroid HT were treated with LT4 for 1 year (n = 10). The other half (n = 11) were never treated with LT4. TL were obtained by fine-needle aspiration biopsy (FNAB). Thirteen healthy subjects (C) without medical history of thyroid disease served as controls concerning PBL, and patients with non-toxic nodular goiter (NG; n = 10) served as controls concerning TL. Thyroid-derived T-helper cells were found more frequently in euthyroid patients with HT compared to patients with NG (p < 0.01). After 1 year of therapy with LT4, TPO-Abs and B lymphocytes decreased significantly only in the treated group of euthyroid patients with HT (p < 0.05). In contrast, TPO-Abs levels did not change or even increased in untreated euthyroid patients with HT. Thyroid volume did not differ before and after therapy. Prophylactic treatment of euthyroid patients with HT reduced both serological and cellular markers of autoimmune thyroiditis. Therefore, prophylactic LT4 treatment might be useful to stop the progression or even manifestation of the disease. However, the long-term clinical benefit of prophylactic LT4 therapy in euthyroid patients with HT is yet to be established.

Nerve Fibers and Histopathology of Endometriosis-Harboring Peritoneum

Study Objective To evaluate the presence of nerve fibers and histopathology of normal peritoneum and endometriosis-harboring peritoneum. Design Prospective, nonrandomized study (Canadian Task Force classification II-1). Setting University hospital. Materials Peritoneal specimen from 40 women with laparoscopic findings of endometriosis (24 confirmed histopathologically, group H, 16 diagnosed by laparoscopy, group L) and from 9 women with no endometriosis (controls). Intervention Histopathologic examination of peritoneal specimens with nerve fibers identified by immunocytochemistry staining with an antibody to neurofilament. Measurements and Main Results No differences in mean nerve score were seen among the three groups. Degrees of lymphocytic infiltration and mesothelial hyperplasia were higher in group H than in the other two groups (p <0.01 and <0.05, respectively). The degree of lymphocytic infiltration was significantly higher in group L than in the control group (p <0.05). There were no differences in all measurements between women in group H who experienced chronic pelvic pain and those who did not. Conclusion The presence of nerve fibers in peritoneum is not related to endometriosis. Endometriosis-harboring peritoneum contains more lymphocytic infiltration than normal peritoneum.

Heart Transplantation in Neonates: Achievements, Controversies, and Challenges for the Future

After completing this article, readers should be able to: 1. Compare the results of pediatric heart transplantation with those of transplantation in adults, including the survival rates. 2. Compare and contrast the indications for pediatric heart transplant among those younger and older than 1 year of age. 3. List the common complications after pediatric heart transplantation. 4. Compare and contrast new immunosuppressive agents (tacrolimus, mycophenolate, humanized anti-Tac antibodies) and standard therapies (cyclosporine, azathioprine, prednisone, antithymocyte globulin). 5. Describe the controversy surrounding the proper management of infants who have hypoplastic left heart syndrome. Not long after the first successful human heart transplant was performed, the first neonatal heart transplant was attempted. In December of 1967, Kantrowitz and colleagues at Maimonides Hospital in New York transplanted the heart of an anencephalic infant into a 3-week-old who had tricuspid atresia. Although the recipient survived only 6.5 hours, the technical feasibility of cardiac transplantation in the pediatric patients was proven. Thirty-three years later, heart transplantation has gained widespread acceptance as a standard treatment modality for end-stage cardiomyopathy or noncorrectable congenital heart disease in infants and children. The 2 years following Barnard’s pioneering first transplant saw explosive growth in the field of adult heart transplantation, but poor 1-year survival dampened much of the initial enthusiasm and with it, any hope for bringing heart transplantation to the pediatric population. Most centers eventually abandoned the procedure, and many physicians denounced the concept. However, a few centers persisted, most notably Dr Norman Shumway and colleagues at Stanford, gradually improving survival through strong collaborations with basic immunologists and cardiac pathologists. By the mid-1970s, heart transplantation had been extended successfully to teenagers. The introduction of the “wonder drug” cyclosporine in 1980 so dramatically improved survival in adult cardiac transplant recipients that the extension of transplantation to even younger patients became feasible. Almost as important as …

Clinical significance of spontaneous apoptosis in advanced gastric adenocarcinoma

Spontaneous apoptosis has been detected in gastric carcinoma. However, the clinicopathological significance of this remains unclear. The objective of this study was to investigate the correlation between spontaneous apoptosis and the clinicopathologic and biologic characteristics of advanced gastric carcinoma. In addition, the prognostic significance of spontaneous apoptosis of tumors was evaluated. The occurrence of apoptotic cell death (apoptotic index [AI]) in 97 patients with advanced gastric carcinoma was analyzed by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end labeling method. The Ki-67 labeling index (LI), expression of p53 and p21, DNA ploidy pattern, microvessel density (MVD), density of dendritic cells (DCs) in tumors, and degree of lymphocytic infiltration (LI) of the tumors were compared with the AI for each patient. In addition, the prognostic significance of AI was evaluated in these patients. The mean AI of the 97 tumors was 2.05% (range, 0-11.31%). Statistical analyses revealed significant correlations between the AIs and the Ki-67 LIs (P = 0.0004) and between the AIs and the density of DCs (P = 0.0007), as well as an inverse correlation between the AIs and the intratumoral MVD (P = 0.0064). In addition, the AI of 47 tumors with high grade LI (2.94+/-2.51%) was significantly higher than that of 50 tumors with low grade LI (1.22+/-0.93%) (P<0.0001). However, the authors failed to find a significant correlation between the AIs and expression of p53 and p21 and the DNA ploidy pattern. In 93 surviving patients, the 5-year survival rate of 45 patients who had tumors with high AIs (> or =1.47; 82%) was significantly better than that of 48 patients who had tumors with low AIs (<1.47; 60%) (P = 0.0264). The findings of the current study suggest that the tumors with low neovascularization and high local immunoreactivity may regulate their progression by apoptosis. Moreover, less extensive apoptosis in gastric adenocarcinoma may contribute to disease progression and could be correlated with a poorer prognosis.

Flow cytometric analysis of tumour-infiltrating lymphocytes in patients with renal cell carcinoma.

To determine the immunophenotype of tumour-infiltrating lymphocytes (TIL) and peripheral blood lymphocytes (PBL) isolated from patients with renal cell carcinoma (RCC) and to analyse the correlations between the quantity of analysed cell subsets and the progression of the disease. PBL and TIL samples were obtained from 23 patients with RCC at different stages of disease. The immunophenotype of PBL and TIL was measured, and the TNM stage, tumour size, cellular type, histological grade, lymphocytic infiltration and performance status assessed. The predominant mononuclear cells infiltrating the tumour, in all patients, were T lymphocytes (CD3+ median 66.9%, CD8+ median 34.6%, CD4+ median 26.7%). The cells possessing gamma/delta type T cell receptor accounted for a small fraction of the T cells in PBL and TIL (median 5.6% and 3.7%). Tumour-infiltrating T lymphocytes had a significantly higher percentage of cells expressing human leucocyte antigen (HLA) DR (median 30.9%) and CD25 (median 6.2%) antigens than the equivalent populations in peripheral blood from the same patient group (P < 0.001). The degree of T cell activation appeared to negatively correlate with the tumour stage (K = -0.3, P = 0.04). The percentage of natural killer (NK) cells among TIL (median 15.4%) did not reflect the value in PBL. The percentage of B cells in TIL was slightly lower than in PBL and accounted for 5.0% of cells. There was no relationship between the degree of lymphocytic infiltration and either tumour stage or grade but there appeared to be a positive correlation between the intensity of lymphocytic infiltration and the percentage of CD4+ cells in TIL (K = 0.5, P = 0.001). Moreover, the composition of TIL depended on tumour grade, which positively correlated with the percentage of CD8+ cells (K = 0.4, P = 0.005) and negatively with the percentage of NK cells (K = -0.5, P = 0.005). There was an inverse correlation with the percentage of gamma/delta T cells in PBL and the TIL concentration (K = -0.3, P < 0.05). The TIL immunophenotype is different from PBL and is influenced by the histological grade of the tumour. The activation of TIL and its relationship with tumour progression suggests that they might be sensitized and activated by tumour cells.

MHC class II antigen-associated invariant chain on renal cell cancer may contribute to the anti-tumor immune response of the host.

To investigate the association between renal cell cancer (RCC) and the host immune system, we examined the expression of invariant chain (Ii) and HLA-DR on renal cancer. Immunohistochemically, Ii was detected in 53 of the 60 cases of RCC. Significant correlation was found between the expression of Ii and the degree of lymphocyte infiltration. Flow cytometric analysis for HLA-DR and Ii on RCC cell line (ACHN) showed no positive cells, whereas interferon (IFN)-gamma treatment induced HLA-DR. Immunoprecipitation showed the presence of cytoplasmic Ii in ACHN cells. In addition, IFN-gamma-treated ACHN cells showed more intense signals than untreated cells. These results suggest that Ii associated with class II antigens on RCC may contribute to the anti-tumor immune response of the host and that IFN-gamma, which is administered for the treatment of cancer, may increase the immunogenicity of RCC.

MHC class II antigen-associated invariant chain on renal cell cancer may contribute to the anti-tumor immune response of the host.

To investigate the association between renal cell cancer (RCC) and the host immune system, we examined the expression of invariant chain (Ii) and HLA-DR on renal cancer. Immunohistochemically, Ii was detected in 53 of the 60 cases of RCC. Significant correlation was found between the expression of Ii and the degree of lymphocyte infiltration. Flow cytometric analysis for HLA-DR and Ii on RCC cell line (ACHN) showed no positive cells, whereas interferon (IFN)-K treatment induced HLA-DR. Immunoprecipitation showed the presence of cytoplasmic Ii in ACHN cells. In addition, IFN-K-treated ACHN cells showed more intense signals than untreated cells. These results suggest that Ii associated with class II antigens on RCC may contribute to the anti-tumor immune response of the host and that IFN-K, which is administered for the treatment of cancer, may increase the immunogenicity of RCC.

Effect of acupuncture on immunologic function and histopathology of transplanted mammary cancer in mice

This experiment mainly describes the effects of acupuncture on immunologic function and histopathology of transplanted mammary cancer in mice. The results were as follows: in acupuncture group, NK cell activity and T-lymphocyte positive rate of acid alpha-naphthyl acetate esterase (ANAE) and lymphocyte transformation rate were all increased. Compared with the control group, there was a significant difference (P < 0.01). The difference was insignificant, when compared with normal group (P > 0.05). Comparing the pathology grading of acupuncture group with control group, it showed marked difference in pathological section (P < 0.01). Adenoid structure and the degree of lymphocytic infiltration also have marked difference between acupuncture and control group (P < 0.05). Less tumour volume in acupuncture than control group were observed (P < 0.01). This indicated that acupuncture might increase the immunologic function of transplanted mammary cancer in mice and inhibit the growth of mammary cancer and enhance both differentiation level of mammary cancer cells and lymphocytic infiltration. Possibly acupuncture mightt reduce the malignancy of mammary cancer cells.

Antibody to gp39, the ligand for CD40 significantly inhibits the humoral response from Graves' thyroid tissues xenografted into severe combined immunodeficient (SCID) mice.

Experimental evidence suggests that interference with gp39-CD40 interactions may have therapeutic potential in prevention of certain autoimmune disorders (i.e., collagen-induced rheumatoid arthritis). The binding between CD40 expressed on mature B cells and CD40 ligand (CD40L, gp39) transiently expressed on activated T helper cells (Th) further stabilizes the interactions (between Th and B cells) and co-ordinates the responses of the interacting cells during antigen presentation, and is essential for thymus-dependent humoral immunity. Graves' disease is the most common form of hyperthyroidism, in which hyperactivity of the thyroid gland is due to an autoantibody directed against the thyrotropin receptor (TSHR). The main objective of our study was to determine the role of interactions between gp39 and CD40 in "an established" human Graves' disease (GD). Severe combined immunodeficient (SCID) mouse served as a vehicle for human Graves' thyroid tissue. This experimental setting allows us to study, observe, and immunomodulate human autoimmune tissue in so called in vivo condition. We studied the effects of ip administration of anti-gp39 mAb on humoral response, thyroid function tests, expression of adhesion molecules, and HLA-DR on human thyrocytes and histopathological changes from human GD thyroid tissue xenografts. GD thyroid tissue from 4 patients was xenografted into 20 SCID mice (0.8 g/mouse). Human immunoglobulin G (IgG) levels became detectable in SCID mice 1 week after xenograftment. Ten SCID mice were sequentially administered anti-gp39 mAb (250 micrograms/mouse/ dose) ip every 4 days until the end of the experiment. Ten control animals were injected with vehicle (PBS) in similar fashion. Blood samples were taken every 2 weeks from the tail veins for measurement of the humoral response [human IgG, thyroid-stimulating antibody (TSAb), antithyroperoxidase (anti-TPO), and antithyroglobulin (anti-Tg), Abs], and thyroid function tests. After 8 weeks, animals were sacrificed and thyroid tissue was examined histologically. The humoral response from the intrathyroidal lymphocytes was measured and the tissue morphology of GD was preserved during the 8-week period in phosphate-buffered saline (PBS)-treated SCID mice xenografted with GD xenografts. However, administration of anti-gp39 mAb completely blocked or significantly decreased the humoral response in all treated animals. On the other hand, no significant histological changes were associated with the administration of anti-gp39 mAb. The degree of lymphocytic infiltration in thyroid tissue xenografts was comparable in both groups. Serum thyroxine values were normal in both groups. In spite of a profound immunosuppressive effect on the humoral response by directly blocking CD40-gp39 interactions in vivo, this did not result in complete deletion of the responding Th in the thyroid specimens.

Biologic characteristics of esophageal epithelial dysplasia assessed by proliferating cell nuclear antigen.

Proliferating cell nuclear antigen (PCNA) correlates with the cell proliferative state. Using a PCNA specific monoclonal antibody, various malignant neoplasms have been assessed for cell proliferation and malignant potential. However, there are few studies regarding the expression of PCNA in esophageal dysplasia. PCNA expression was immunohistochemically determined in resected specimens from 27 patients with superficial esophageal carcinoma that contained areas with various degrees of dysplasia, carcinoma in situ (CIS), and carcinoma invading the mucosal layer. The authors estimated the cell proliferative activity and biologic characteristics of the basal and parabasal cells of these esophageal epithelial disorders. The degrees of PCNA labeling index (PCNA LI) of the basal layers were lower than those of the parabasal layers in normal epithelium and dysplastic lesions, respectively, whereas no difference in CIS was recognized between the two layers. The proportion of PCNA LI in the basal layer of moderate dysplasia was lower than that in the basal layer of severe dysplasia. Conversely, there were no statistical differences between severe dysplasia and CIS in both basal and parabasal layers. In terms of lymphocytic infiltration beneath the dysplasia, there was a close relationship between the degree of lymphocytic infiltration and the PCNA index of the basal and parabasal layers. PCNA expression may be a useful marker to reflect the biologic characteristics of esophageal dysplasia, suggesting that a high grade of dysplasia is as serious a lesion as esophageal carcinoma.

Thyroiditis : Thyroid function and cytologic correlation - A study of 66 cases

During a study period from 1992 to 1994, 66 cases which were diagnosed as thyroiditis by Fine Needle Cytology were evaluated for functional status by assay of thyroid hormone levels. None of these patients had received treatment for their condition. Six of the 66 patients were diagnosed as sub-acute thyroiditis and the rest as lymphocytic thyroiditis without further qualification. Smears of lymphocytic thyroiditis were grouped into four morphological groups namely oxyphilic (21), mixed (16), focal (9), and hyperplastic (14 cases). The degree of lymphocytic infiltration as well as severity of follicle destruction was also graded. An attempt was made to correlate cytological findings with functional status of the thyroid gland. Eighty six percent of cases with severe follicle destruction and 90% of cases in the oxyphil subgroup were hypothyroid. Predictability was further bettered when both these findings were considered together. All 14 cases in the oxyphilic sub-group with significant destructive changes were hypothyroid. All six cases of subacute thyroiditis had elevated levels of thyroid hormones.

CD31, CD62E, and CD62P Identify a Specific Pattern of Endothelial Activation in Graves' Disease

The different degrees of lymphocytic infiltration observed in Graves' disease, Hashimoto's disease, and De Quervain thyroiditis suggest that the regulation of adhesion molecules expressed on endothelial cells could be different in these autoimmune disorders of the thyroid. Using immunohistological techniques, we observed that thyroid samples from patients with Graves' disease displayed a characteristic pattern of capillary proliferation, with CD62P, CD62E, and CD31 expression on endothelial cells. This was different from the pattern and size of endothelial cells expressing adhesion molecules in the two other types of thyroiditis where larger vessels and high endothelial venules were stained. Almost no signs of endothelial cell activation could be seen in a comparative series of non-autoimmune disorders.

Assessment of p53 expression in nasopharyngeal carcinoma

We analyzed the expression of the p53 protein by inununohistochemical methods from 101 patients with nasopharyngeal carcinoma (NPC): 24 with NPC and dysplastic lesions adjacent to carcinoma and 14 with primary and metastatic specimens. Ninety-six of 101 lesions (95%) had detectable p53 protein in the nuclei of tumor cells, indicating that overexpression of the p53 protein might be closely associated with NPC. Among 24 patients who had NPC and dysplastic lesions adjacent to carcinoma, 19 of the dysplastic lesions (79.2%) and 22 of the carcinomas (91.7%) showed positive staining for the p53 protein. In dysplastic epithelia p53 antigenicity was generally in a basal location. The significant association of p53 expression in NPC and dysplastic lesions adjacent to carcinoma ( P < .0001, Fisher's exact probability test) suggests that p53 overexpression seems to occur at an early stage in the development of NPC. p53 expression in NPC does not correlate with histological grading, degree of lymphocytic infiltration between tumor cells, clinical stage, sex, or age ( P > .05, chi-squared test). A comparison of p53 expression between primary and metastatic NPC was performed in 14 lesions. Although the p53 protein was consistently expressed in primary and metastatic tumor cells, there was no significant difference in p53 expression in both distinct but related lesions ( P > .05, paired t-test). Our results suggest that the association of overexpression of the p53 protein in NPC may not be indicative of a mutant type p53 protein.

SOLUBLE CTLA4Ig MODIFIES PARAMETERS OF ACUTE INFLAMMATION IN RAT LUNG ALLOGRAFT REJECTION WITHOUT ALTERING LYMPHOCYTIC INFILTRATION OR TRANSCRIPTION OF KEY CYTOKINES1

The efficacy of CTLA4Ig in blocking immune activation and allograft rejection (AR) was tested in an aggressive and rapid model of rat lung AR (Brown Norway [BN]-->Lewis [LEW]). CTLA4Ig is a recombinant soluble protein that binds with high affinity to rat B7/BB1 and other surface molecules on APCs, subsequently blocking the binding of B7/BB1 to CD28/CTLA4 on T cells. This interrupts the costimulatory pathway critical for complete T cell activation and completion of the AR process. Left single-lung transplants were performed between BN-->Lew. Five allograft recipients were examined in each group. At transplantation, animals received 250 micrograms of CTLA4Ig or 250 micrograms of control Ig intraperitoneally daily until sacrifice. Animals were sacrificed on days 2, 4, and 7 after transplant. Control (BN-->Lew) grafts show irreversible rejection by day 7. Syngeneic (Lew-->Lew) grafts show no AR on day 7. AR episodes were graded histologically (stages 0-IV) and pathologic intensity of inflammation was graded on percentage of involvement. Cytokine transcript levels were measured in control and CTLA4Ig-treated animals (n = 5 in each group) on day 7 using reverse transcriptase polymerase chain reaction techniques. The most profound differences were found on day 7 after transplant. The degree of lymphocytic infiltration was greater in the CTLA4Ig group (perivascular: 4 +/- 0 vs. 2.6 +/- 0.6, peribronchial: 4 +/- 0 vs. 2.2 +/- 0.4, and peribronchiolar: 3.6 +/- 0.5 vs. 2 +/- 0.3, P < 0.01). However, in striking contrast, the stage of AR (3 +/- 0 vs. 4 +/- 0, P < 0.01), vasculitis (1 +/- 0.7 vs. 2.6 +/- 0.6, P < 0.05), hemorrhage (0.4 +/- 0.6 vs. 3.2 +/- 0.4, P < 0.01), and necrosis (0 +/- 0 vs. 2.4 +/- 0.5, P < 0.005) were significantly reduced in animals treated with CTLA4Ig. Since CTLA4Ig blocks Th1 cell activation in vitro, we compared the levels of Th1 inflammatory cytokines IL-2, gamma-IFN, and TNF-alpha in the two models. The intragraft ratios (CTLA4Ig/control) were IL-2:0.77, gamma-IFN: 1.29, and TNF-alpha:1.33. Thus, CTLA4Ig did not significantly block intragraft production of Th1 cytokines on day 7.(ABSTRACT TRUNCATED AT 400 WORDS)

In vivo transfer of the human interleukin-2 gene: negative tumoricidal results in experimental brain tumors

The authors have recently shown the feasibility of eradicating brain tumors using in vivo retroviral-mediated transduction of tumors with the herpes simplex thymidine kinase (HStk) gene and ganciclovir therapy. However, thymidine kinase-transduced subcutaneous tumors in immunocompromised (athymic) mice were less responsive to this therapy than in immunocompetent animals, suggesting a role of the immune system in the process of tumor eradication. Broad suppression of humoral and cell-mediated immunity is found in patients with malignant gliomas. Interleukin-2 (IL-2) production and IL-2 receptor expression are decreased in gliomas patients. These findings and the proposed association between lymphocytic infiltration of brain tumors and survival suggest that immune response modifiers may be useful in treating glioma patients. To evaluate the role of local cytokine expression by tumor cells, alone or combined with HStk gene transfer and ganciclovir therapy, the authors investigated the efficacy of tumor (9L gliosarcoma) eradication in Fischer rats by in vitro and in vivo tumor transduction with the IL-2 gene alone or with a combined vector carrying both the HStk and IL-2 genes. Tumors injected with HStk vector-producer cells alone, with or without ganciclovir, and rats inoculated in the brain and subcutaneously with 9L cells that had previously been transduced in vitro served as controls. Murine vector-producer cells (3 x 10(6)/50 microliters) were injected into the brain tumors 7 days after tumor inoculation. Ganciclovir (15 mg/kg) was administered intraperitoneally twice daily for 10 days to animals that received HStk with or without IL-2 vector-producer cells, starting 5 days after producer-cell injection. The experiment was repeated with continuous daily treatment of all rats with oral dexamethasone (0.5 mg/kg). Rats were sacrificed 21 days after tumor inoculation, and the brains were removed for histological and immunohistochemical analysis for IL-2. Within each experimental group, tumors were found in a similar proportion in the dexamethasone-treated and untreated rats. Large brain tumors developed in all 10 rats that had been inoculated with 9L cells which had been pretransduced in vitro with the IL-2 gene, whereas only three of eight rats receiving subcutaneous inoculation of similar cells developed palpable tumors. No enhancement of tumor eradication was observed by adding the IL-2 gene in the HStk vector construct compared to the use of the vector with HStk alone. Lymphocytic infiltration was absent in all dexamethasone-treated rats but was observed in all treatment groups not receiving steroids.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunoreactive thymosin α1 in human thymus and thymoma

Thymosin alpha 1-like immunoreactivity was assessed in human thymus and thymoma tissue extracts by means of a new radioimmunoassay that included an anti-thymosin alpha 1 mouse monoclonal antibody. Thymosin alpha 1-like immunoreactivity levels decreased with age in normal thymuses but not in thymomas. The average thymosin alpha 1-like immunoreactivity level was 45.0 +/- 52.1 ng/mg protein in normal thymuses and 273.9 +/- 205.0 ng/mg protein in thymomas. The average thymosin alpha 1-immunoreactivity level in thymomas was higher than that in normal thymuses. Thymosin alpha 1-like immunoreactivity levels in thymomas appeared to have no relationship to the clinical stage of the thymoma or associated diseases. When viewed according to histologic characteristics, the average thymosin alpha 1-like immunoreactivity level in polygonal cell thymomas (382.5 +/- 192.6 ng/mg protein) was significantly higher than that in the spindle cell thymoma (101.8 +/- 81.2 ng/mg protein). When viewed according to the degree of lymphocyte infiltration, thymomas could be classified according to four grades: absent, scant, moderate, and predominant. In predominant or moderate thymomas, the average thymosin alpha 1-like immunoreactivity level was higher than that in scant or absent thymomas. Also, thymosin alpha 1-like immunoreactivity levels in thymuses of patients with myasthenia gravis were relatively higher than those in patients with normal thymuses.