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The inflammatory response plays an important role in the tissue destruction associated with periodontitis. Bacterial species can regulate the inflammatory responses of host cells, triggered by pathogens. It was hypothesized that, in the field of oral microbiology/immunology, such effects of bacterial interactions on inflammatory host cell responses might also be present. In this study, the effects of beneficial, commensal, and pathogenic species on Aggregatibacter actinomycetemcomitans-induced interleukin-8 (IL-8) production by human cells were investigated. The beneficial species, Streptococcus mitis, Streptococcus salivarius, and Streptococcus sanguinis, were able to lower the IL-8 production triggered by A. actinomycetemcomitans. The inhibitory effect was also achieved by the application of streptococcal supernatants. In contrast, the commensal Streptococcus gordonii caused no reduction, and the pathogen Fusobacterium nucleatum increased IL-8 production by the host cells. These results show that bacterial species can influence the inflammatory responses of host cells triggered by infection with A. actinomycetemcomitans.

We have previously shown that bioactive interleukin-6 (IL-6) is produced by rat and mouse (anterior) pituitary cells in vitro. Since the amount produced correlated with the presence of S-100-containing folliculostellate (FS) cells, these cells were suggested to be a source of IL-6 in the anterior pituitary (AP) lobe. In the present study we used immunocytochemical techniques to confirm this presumption. Freshly isolated mouse pituitary cells were subjected to immunocytochemical procedures whereby two different (neutralizing) monoclonal antibodies (MAb) against mouse IL-6 (6B4 and 20F3) and a polyclonal antiserum raised against bovine S-100 were used as primary antibodies. Single immunostaining revealed a small portion of mouse pituitary cells (about 6.5%) to be positive for IL-6 immunoreactivity with both antibodies. Importantly, the same proportion of cells was found to be IL-6 positive if only the AP was used as the cell source. About 7.5% of the pituitary cells stained for the presence of S-100 immunoreactivity. Positive staining for IL-6 was also found in pituitary cell samples from 2-day-old monolayer cultures and from redispersed 9-day-old histotypic aggregates, which both secreted bioassayable IL-6. In contrast, no IL-6 staining was found in AtT-20 cells, an established ACTH-secreting tumor cell line of the mouse pituitary which did not secrete bioactive IL-6. The specificity of the IL-6 immunostaining was demonstrated by a total loss of staining when MAb 6B4 was omitted or replaced by irrelevant rat IgG. Conclusively, pre-adsorption of the anti-IL-6 MAb (6B4) with recombinant mouse IL-6 totally abolished staining of pituitary cells. Double immunostaining for IL-6 and S-100 revealed that most if not all of the IL-6-containing pituitary cells were positive for S-100. Few of the S-100-containing cells did not stain for IL-6. These results confirm our previous hypothesis that FS cells, characterized by immunostaining of S-100 protein, contain bioactive and immunoreactive IL-6 and therefore are very likely producers of IL-6 in the AP. Furthermore, our results suggest that IL-6 is implicated in the local regulatory role ascribed to FS cells in the pituitary gland.

Defined by histological criteria, Castleman's disease (CD) is a clinically and histologically heterogeneous syndrome. The functional status of immune cells in affected tissues may vary between the different forms of the disease. To address this question, the expression of cytokine genes in eight CD lymph nodes was analyzed by in situ hybridization. Two lymph nodes were taken from patients with a localized form of the disease associated with systemic manifestations, two from patients with a localized form without systemic symptoms, and four from patients with a multicentric form. Five lymph nodes exhibiting a benign follicular hyperplasia were used as controls. The interleukin-6 (IL-6) gene was expressed at a very high level in two cases: the two localized forms of CD associated with systemic manifestations. IL-6 gene overexpression occurred inside follicles of these lymph nodes. The morphology of follicular cells hybridizing with the IL-6 probe or labeled with an anti-IL-6 monoclonal antibody suggested that follicular dendritic cells expressed the IL-6 gene. In contrast, no IL-6 gene expression was detected inside follicles of the six other CD lymph nodes or of the five control lymph nodes. In interfollicular areas, IL-6 gene-expressing cells were detected in all lymph nodes by both in situ hybridization and immunohistochemistry. In CD lymph nodes, positive cells were located outside sinuses, in close contact with blood vessels and plasma cells. This distribution was clearly different from that observed in control lymph nodes, in which IL-6 gene-expressing cells were present inside sinuses. A similar difference between CD and control lymph nodes was observed for the distribution of IL-1 beta and IL-1 alpha gene-expressing cells in interfollicular areas. The morphology of interfollicular IL-6-producing cells was heterogeneous, consistent with that of macrophages, interdigitating cells, lymphocytes, and endothelial cells, and different from that of plasma cells. Taken together these results show that CD is consistently associated with a particular pattern of IL-6 gene expression in interfollicular areas whereas elevated IL-6 gene expression inside follicles only occurs in the localized form of the disease associated with systemic manifestations. The variable pattern of IL-6 gene expression as well as the clinical and histologic heterogeneity of CD indicate that different immune mechanisms may be involved in the different forms of this disease.

Monocyte-macrophage polypeptides (monokines) cause synovial cells to increase the levels of putative mediators of destruction and inflammation. This interaction may account for some of the properties of rheumatoid pannus. We report here that samples of purified human interleukin-lfi (IL-lp) and recombinant IL-la stimulate both the plasminogen activator activity and prostaglandin Ez levels of human synovial fibroblast-like cells. The same holds true for purified pig IL-1 (catabolin) and recombinant murine IL-1. The elevation in plasminogen activator activity was inhibited by indomethacin, and this suggests that endogenous prostanoids are important in the IL-1-mediated stimulation of proteinase activity.

Purpose The current COVID-19 pandemic is transforming our urologic practice and most urologic societies recommend to defer any surgical treatment for prostate cancer (PCa) patients. It is unclear whether a delay between diagnosis and surgical management (i.e., surgical delay) may have a detrimental effect on oncologic outcomes of PCa patients. The aim of the study was to assess the impact of surgical delay on oncologic outcomes. Methods Data of 926 men undergoing radical prostatectomy across Europe for intermediate and high-risk PCa according to EAU classification were identified. Multivariable analysis using binary logistic regression and Cox proportional hazard model tested association between surgical delay and upgrading on final pathology, lymph-node invasion (LNI), pathological locally advanced disease (pT3-4 and/or pN1), need for adjuvant therapy, and biochemical recurrence. Kaplan-Meier analysis was used to estimate BCR-free survival after surgery as a function of surgical delay using a 3 month cutoff. Results Median follow-up and surgical delay were 26 months (IQR 10-40) and 3 months (IQR 2-5), respectively. We did not find any significant association between surgical delay and oncologic outcomes when adjusted to pre-and post-operative variables. The lack of such association was observed across EAU risk categories. Conclusion Delay of several months did not appear to adversely impact oncologic results for intermediate and high-risk PCa, and support an attitude of deferring surgery in line with the current recommendation of urologic societies.

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