Local Immune Function Research Articles

Correlation Between in Vivo Accumulation and in Vitro Adhesion of Liver associated Lymphocytes in and Around Liver Adenocarcinoma Metastases

Liver is a major site for formation of metastases. The local immune function of liver is associated with a specific mononuclear cells population transiently retained in the liver, originating most probably from blood. Liver mononuclear cells consist mainly of natural killer (NK) cells, T gamma delta cells and T cells expressing NK molecules. The latter are found in low proportions in peripheral blood [1-3]. Tumoricidal activity requires cell to cell contact initiated by functionally relevant adhesion molecules. It is not clear which adhesion molecules are responsible for the site directed traffic and binding of mononuclear cells within the tumor microenvironment and which populations of mononuclear cells reveal prediction to accumulate around and within the tumor tissue during postextravasation phase of tumor growth [4-6]. Defining these populations and molecules may help to elucidate the mechanisms that guide mononuclear cells to and within the tumor microenvironment. This may be important for two reasons: first evaluation of their cytotoxic capacity, second isolation and culturing cells for transfection with cytokine genes or arming with antitumor chemicals for tumoricidal therapy. Aim of the study was to: Characterize peripheral blood mononuclear (PBM) and liver sinusoidal wash-out cells (LSWC) of normal and tumor bearing rats revealing predilection to in vitro adhere to the tumor tissue; Investigate the proliferating liver tumor properties modifying in vitro adhesion of PBM and LSWC to the tumor foci.

Dietary Regulations of the Intestinal Barrier Function at Weaning

Weaning is a complex phase when the mammal suffers the action of different stressors that contribute to negatively affect the efficiency of the intestinal mucosa and of the whole local integrated system, that acts as barrier against any nocuous agent. The components of this barrier are mechanical, chemical, and bacteriological; immunological and not. The development of contact with a saprophyte microflora and the maintenance of feed intake after the interruption of motherly nutrition are essential for the maturation of an equilibrated local immune function and for a functional integrity of villi. Opportunities and limits of some dietary strategies that can contribute to reduce negative effects of weaning on health and performance are discussed. Knowledges on the possible mechanism of action of probiotics are upgraded, particularly for their supposed role in the balance between different immune functions (effectory/regulatory). Some tools to control pathogen microflora are reviewed (acids, herbs, immunoglobulin sources) and practical feeding systems are proposed. (Asian-Aust. J. Anim. Sci. 2003. Vol 16, No. 4 : 596-608)

T-cell proliferation induced by local application of LPS in the nasal mucosa of nonatopic children

Background: Recently, there has been a great deal of interest in the role of bacterial products in altering the allergic immune response in early life. Objective: We sought to develop a model of bacterial inflammation in human subjects to characterize the ex vivo response to LPS in the nasal mucosa of young nonatopic children. Methods: Using the explant technique, we cultured nasal mucosa in the presence or absence of increasing concentrations of LPS (0.001-1 μg LPS/mL) for 24 hours. Immunocytochemistry and in situ hybridization were used to phenotype the cells and cytokines in the explant, and immunofluorescence was used to study proliferation of T cells in explants cultured with LPS and 5-bromo-2′-deoxyuridine (BrdU). Results: CD68, CD3, tryptase, elastase, IFN- γ IL-12, and IL-10 immunoreactivity was detected in unstimulated tissue. LPS stimulation caused a dose-dependent increase in the number of CD3+ (n = 7, P <.05), CD68+ (n = 7, P < .01), elastase-positive (n = 7, P < .01), tryptase-positive (n = 7, P < .05), IL-2 –positive (n = 6, P < .05), IL-12 –positive (n = 6, P < .05), and IFN- γ–positive (n = 6, P < .05) cells compared with media alone. LPS had no effect on major basic protein, IL-4, IL-5, or IL-13 immunoreactivity. LPS (0.1 μg/mL) caused an increase in the number of BrdU-positive cells as early as 2 hours after incubation (n = 8, P < .001). The maximal BrdU immunoreactivity was seen 24 hours after incubation with LPS, at which time approximately 70% of BrdU-positive cells were CD3+ T cells. Conclusions: Our results suggest that LPS is capable of inducing local inflammation, TH1 cytokine immunoreactivity, and proliferation of CD3+ activated T cells in the absence of de novo cell recruitment. This model holds promise for future studies investigating the importance of bacterial products in regulating local immune function in young atopic children. (J Allergy Clin Immunol 2002;110:771-6.)

Immunoglobulin A secretion into pancreatic juice as a novel marker of local immune defense and exocrine pancreatic function.

The importance of secretory immunoglobulin A (IgA) of local immune defense in the gastrointestinal tract has gained increasing acceptance. Bacterial contamination is a major factor related to mortality in acute pancreatitis. However, very little is known about IgA in pancreatic juice. Pure pancreatic juice was collected from 40 patients undergoing pancreatoduodenectomy. The patients were divided into three groups according to the degree of preoperative pancreatic duct obstruction, as follows: normal, narrowed, and obstructed. IgA concentration, amylase activity, and daily volume of pancreatic juice were measured. Daily IgA secretion into pancreatic juice was constant during the early period after the operation. The concentration of IgA in the control group was 5 +/- 0.8 microg/ml, and IgA daily secretion was 1.2 +/- 0.2 mg/day. Pancreatic duct obstruction resulted in a marked decrease in both amylase and pancreatic juice secretion. The concentration of IgA, however, was markedly increased in the narrowed group (11.1 +/- 2.4 microg/ml) and the obstructed group (32.5 +/- 5.4 microg/ml). The concentration of amylase increased with the increase in pancreatic juice. Conversely, the concentration of IgA increased with the decrease in volume of pancreatic juice. Similarly, the increased in IgA concentrations positively correlated with the decrease in amylase activity. In conclusion, the mechanisms that modulate IgA secretion in the human pancreas are essentially different from those that modulate digestive enzyme and fluid secretion. IgA in pancreatic juice may play an important role in pathological conditions such as pancreatic duct obstruction. As such, the measurement of IgA in pancreatic juice may potentially be used as a new marker of local immune defense and exocrine pancreatic function.

Pathophysiology of Infections After Internal Fixation of Fractures

Infection complicating internal fixation of fractures is a serious complication that is difficult to treat. Whenever metallic devices are implanted in vivo, successful biointegration requires that host cells colonize the highly reactive implant surface. Bacteria such as staphylococci can also become adherent to metallic or polymeric implants and will compete with host cells for colonization of the implant surface. Once adherent, these bacteria form a biofilm and undergo phenotypic changes that make them resistant to the normal host immune response as well as to antibiotics. Furthermore, metallic implants themselves cause specific deficits in the function of the local immune system that may render the host response to infection inadequate. Any associated soft-tissue injury causes even greater impairment of local immune function. Despite the potentially detrimental impact of internal fixation, fracture stability is of paramount importance in achieving fracture union and in preventing infection. It has been demonstrated in animal models that contaminated fractures without internal fixation develop clinical infection more commonly than similar fractures treated with internal fixation at the time of colonization. Because of the potential for infection whenever internal fixation is utilized, appropriate prophylactic antibiotic coverage for staphylococci and Gram-negative organisms should be provided. Open wounds and severely damaged soft tissues require aggressive management so that a viable soft-tissue envelope is maintained around the implant. Host factors such as smoking and malnourishment should be corrected. Early diagnosis and aggressive treatment of implant-related infection with antibiotics, debridement, and maintenance of stable internal fixation are essential to successful treatment.

Adenovirus vector-mediated gene transfer to regional lymph nodes.

Regional lymph nodes (RLNs) possess important immune functions and represent a major pathway of metastasis for solid tumors. Given these facts, the ability to transfer exogenous genes to the RLNs with the goal of manipulating the local immunological milieu would be desirable. On the basis of the hypothesis that a significant proportion of adenovirus (Ad) gene transfer vectors traffic through the lymphatics, E1-E3- Ad vectors were injected into the hind footpad of C3H/He mice and the RLNs assessed for vector trafficking and transgene expression. A low dose (10(9) particles) of an Ad vector encoding the firefly luciferase gene (Ad-CMV.Luc) resulted in luciferase expression only in the injection site and RLNs, with no detectable systemic (liver, spleen, lung) expression. At a higher dose (10(11) particles), some expression could be detected systemically in addition to the RLNs, but at levels in liver 14-fold less than in the RLNs. Transgene expression in the RLNs was transient, peaking at 1 day, decreasing markedly by 7 days. At high doses (10(11) particles), interruption of draining lymphatics decreased the amount of systemic dissemination 22-fold, suggesting that a large proportion of the vector trafficks through the lymphatics before reaching the systemic circulation. Administration of a vector encoding the jellyfish green fluorescent protein gene (AdCMV.GFP, 10(11) particles) showed that transgene expression in the RLNs was primarily in the cortical area. After footpad injection of a fluorescent-labeled Ad vector (Cy3-AdCMV.Null), fluorescent virions were visualized in the draining lymph. Regional lymph collected from animals injected in the footpad with AdCMV.Luc (10(11) particles) contained functional vector. Augmentation of local immune function in the RLNs was achieved by footpad administration of an Ad vector encoding murine IL-12, resulting in high mIL-12 and IFN-gamma levels in the regional, but not distant, nodes. These data demonstrate that expression of exogenous genes in RLNs is easily accomplished with Ad vectors, Ad vector dissemination occurs primarily via the lymphatics after footpad administration in mice, and basic immune functions in the RLNs can be manipulated by Ad-mediated gene transfer in vivo.

Local neurochemicals and site-specific immune regulation in the CNS.

Although it is often described as "immunologically privileged," the brain can display vigorous immune activity, both clinically and experimentally. The underlying control mechanisms are under active study. Here we shift attention from the brain as a whole to its diverse microenvironments. We review evidence that immune regulation in the brain is site-specific, and that local neurochemicals contribute to the site-specific control. Key points are illustrated by recent work from a rat model in which local injection of the proinflammatory cytokine, IFN-gamma, was used to modulate 2 essential aspects of the cell-mediated immune response: T cell entry from the blood, and expression of the MHC proteins that are needed to present antigen to the newly entered T cells. A growing number of neurologic disorders are known to be exacerbated by the immune/inflammatory network. Understanding the factors that influence local immune function may help explain the distribution of localized CNS damage and, more importantly, may suggest new therapeutic approaches for both desirable and unwanted responses.

Increased concentrations of iron and isoferritins in the lower respiratory tract of patients with stable cystic fibrosis.

Reactive oxygen species may contribute to airway injury in patients with cystic fibrosis (CF) and iron catalyzes oxidant injury by promoting generation of highly reactive hydroxyl radicals. Iron in the lower respiratory tract may be free, ferritin bound (from which iron can be reductively mobilized), or transferrin bound (which generally prevents iron mobilization). Ferritin is composed of subunits that are heavy (H) or light (L), and H-rich ferritins have additional biologic effects including inhibition of lymphocyte proliferation and cell growth. To assess concentrations of iron and iron-binding proteins in the lower respiratory tract of patients with CF, we measured iron (ferrozine), L-ferritin, H-ferritin, and transferrin (enzyme-linked immunosorbent assay [ELISA]) in bronchoalveolar lavage (BAL) fluid recovered from stable patients with CF (n = 8), healthy nonsmokers (NS; n = 8), or heavy cigarette smokers (HS; n = 8). Iron was detected in BAL fluid from patients with CF and HS, but not NS, with higher iron concentrations in patients with CF (42.0 +/- 11.6 microgram/dl) than in HS (9.9 +/- 2.6 microgram/dl, p < 0.05). Ferritin was present in all BAL fluids, with higher total ferritin (L + H) in patients with CF (647 +/- 84 ng/ml) than in HS (181 +/- 25 ng/ml, p < 0.005) or NS (9 +/- 3 ng/ml, p < 0.0005). Ferritin recovered from HS and NS lungs was < 2% H type, whereas ferritin in CF lungs was > 40% H-type ferritin. Transferrin concentrations in BAL fluid were not different in any group. Tumor necrosis factor (TNF)-alpha was present only in BAL samples from patients with CF. To assess whether TNF-alpha contributed to H-ferritin accumulation in CF lungs, we treated lung epithelial cells (A549) with iron alone (FeSO(4), 10-40 microM) or with iron and TNF-alpha (5-20 ng/ml). Iron-treated A549 cells synthesized almost entirely L-ferritin whereas exposure to TNF-alpha with iron caused a dose-dependent increase in accumulation of H-type ferritin. These findings suggest that oxidant injury could be promoted in lungs of patients with cystic fibrosis by iron mobilized from extracellular ferritin and, in addition, that TNF-alpha-promoted accumulation of H-type ferritin may impair local immune function and cell growth.

Recurrences and Relation to Tumor Growth Potential and Local Immune Response in Node-Negative Advanced Gastric Cancer

Biological characteristics and the prognosis for subjects with node-negative advanced gastric cancer have been given little attention in related literature. We analyzed data on 112 patients with serosally invasive gastric cancer who were lymph node metastasis-negative; all had been surgically treated in the Department of Surgery II, Kyushu University Hospital, between 1970 and 1992. Recurrences and relation to the growth potential of the tumor and local immune response were examined. Thirty patients died with a recurrence of the gastric cancer, and in these patients, the tumor was larger, the whole stomach was more frequently involved and infiltrative growth was more common, compared to findings in patients who were recurrence-free. Peritoneal recurrence was evident in half the number of patients and the 5-year survival rate was 74.5%. Tumor growth potential was evaluated, based on the level of proliferating cell nuclear antigen (PCNA) of the primary tumor and on dendritic cell infiltration into the tumor, determined as a level of local immune function of the host. Higher growth potential and lower immune levels were more frequent in patients with recurrences. Multivariate analysis revealed that tumor size and PCNA labeling index were significant prognostic factors for node-negative gastric cancers. In a subset of advanced gastric cancers, there was no apparent distinct lymph node metastasis and the prognosis was better. However, cancer cells with a higher growth potential and a lower immune response in the host can biologically amplify and mainly infiltrate the gastric wall, extend to the serosa and disseminate transserosally into the peritoneum.

Combined analysis of tumour neoangiogenesis and local immune response in advanced gastric carcinoma.

Neovascularization and host immune response are important in the growth and metastasis of solid tumours. Thus, microvessel density, and dendritic cell (DC) infiltration, which was thought to be an indicator of local immune function, were examined by immunohistochemistry and their prognostic significance was determined in patients with advanced gastric carcinoma. The 5-year survival rates in patients with both low microvessel counts and marked DC infiltration, in patients with either low microvessel counts or marked DC infiltration, and in patients with both high microvessel counts and slight DC infiltration were 82.6%, 68.6%, and 30.2%, respectively, the differences were statistically significant. Moreover, the multivariate analysis showed that combined analysis of microvessel counts and DC density was an independent prognostic indicator. Our findings indicate that combined analysis of tumour neoangiogenesis and local immune response might be useful for predicting prognoses of patients with advanced gastric carcinoma.

Lymph node metastasis and relation to tumor growth potential and local immune response in advanced gastric cancer.

To evaluate the relation between the degree of lymph node metastasis and the growth potential of tumour cells and the local immune function in gastric cancer, we analyzed data on 444 patients with advanced serosally invasive gastric cancer who underwent curative gastrectomy. Tumour growth potential was evaluated based on the value proliferating cell nuclear antigen (PCNA) in the primary tumour, and dendritic cell infiltration into the tumour was determined as an indicator of local immune function. The values of PCNA labeling in the primary tumour increased and the infiltration of dendritic cells into the tumour decreased in relation to the extent of lymph node metastasis. High growth potential and low immune function were seen in cases with n3 lymph node metastasis. There was a reverse relation between the PCNA labeling index and dendritic cell infiltration. A variety of forms of recurrence was noted in patients with lymph node metastasis while the prognosis was less favorable, in relation to the degree of lymph node metastasis. Thus, the potential for nodal spread appears to be associated with the growth potential of tumour cells and with the local immune status of the tumour.

Lymph node metastasis and relation to tumour growth potential and local immune response in advanced gastric cancer

To evaluate the relation between the degree of lymph node metastasis and the growth potential of tumour cells and the local immune function in gastric cancer, we analyzed data on 444 patients with advanced serosally invasive gastric cancer who underwent curative gastrectomy. Tumour growth potential was evaluated based on the value proliferating cell nuclear antigen (PCNA) in the primary tumour, and dendritic cell infiltration into the tumour was determined as an indicator of local immune function. The values of PCNA labeling in the primary tumour increased and the infiltration of dendritic cells into the tumour decreased in relation to the extent of lymph node metastasis. High growth potential and low immune function were seen in cases with n3 lymph node metastasis. There was a reverse relation between the PCNA labeling index and dendritic cell infiltration. A variety of forms of recurrence was noted in patients with lymph node metastasis while the prognosis was less favorable, in relation to the degree of lymph node metastasis. Thus, the potential for nodal spread appears to be associated with the growth potential of tumour cells and with the local immune status of the tumour. Int. J. Cancer 74:224-228, 1997. © 1997 Wiley-Liss Inc.

Vasoactive intestinal peptide induces S(alpha)/S(mu) switch circular DNA in human B cells.

Vasoactive intestinal peptide (VIP), a major neurotransmitter of peripheral nerves, has been suggested to function in host defense by regulating local human immune function. Indirect evidence has been marshaled that VIP can function as a switch factor for IgA in human Ig isotype recombination. In this study we directly tested the ability of VIP to function as a factor driving human B cells into IgA producing cells by assessing its ability to induce switch circular DNA representing direct mu to alpha switching. In addition we determined the generation of alpha germ-line transcripts and measured the level of IgA protein produced. Stimulation with VIP and CD40 mAb induced IgA production by human IgD+ B cells while VIP or CD40 alone failed to do so. Stimulation of purified IgD+ B cells with VIP plus CD40 mAb induced generation of switch circular DNA representing in vitro driven isotype switching from mu to alpha. CD40 mAb alone induced alpha germ-line transcripts but not IgA switch circles. Thus VIP, a neurogenic factor, can induce alpha-specific switching in CD40-activated human B cells and may thereby play an important role in directing the humoral immune response at mucosal surfaces.

Clinical and molecular aspects of the pathogenesis of Staphylococcus aureus bone and joint infections

Staphylococcus aureus is an important cause of bone and joint infections. In recent years, significant changes in the incidence of septic arthritis and osteomyelitis have occurred. Haematogenous osteomyelitis is now less common during childhood, but secondary spread of infection to bone or joint from a contiguous site in adults is increasing in incidence. Infection introduced at the time of surgery or arising by the haematogenous route is a significant complication of prosthetic joint implantation, and the effect of bone cement on local immune function may be important in this setting. ALthough S. epidermis is a more common cause of prosthetic joint infection, S. aureus is more difficult to treat. S. aureus produces a number of extracellular and cell-associated factors, but it is unclear what role these have as virulence factors in vivo. Furthermore, it is difficult in animal models to simulate transient bacteraemia followed by non-fulminating septic arthritis or osteomyelitis, as occurs in the patient. Surface factors which may be important in pathogenesis include the cell wall (activates complement and stimulates cytokine release), capsular polysaccharide (promotes adhesion to host cell surfaces), collagen receptors and fibronectin-binding protein. Staphylococcal toxic shock syndrome toxin (TSST-1) and the enterotoxins are superantigens and have the potential to suppress plasma cell differentiation and antibody responsiveness. TSST-1-positive isolates have been shown to cause more severe joint infection in one animal model, but most other studies to date have focused on in-vitro rather than in-vivo effects. There is little evidence supporting a role for coagulase, lipase and the haemolysins in staphylococcal bone and joint infections. Despite the clinical importance of these infections, surprisingly little is known about pathogenesis at the cellular level. Future research should focus on the role of the host immune system in limiting spread of infection, and the expression of virulence factors in animal or other models incorporating isogenic mutant strains.

Defective regional immunity in the respiratory tract of neonates is attributable to hyporesponsiveness of local dendritic cells to activation signals.

A variety of studies suggest that the increased susceptibility of neonates to allergic and infectious respiratory diseases is due to delayed postnatal maturation of local mucosal immune function. We have recently demonstrated that the postnatal development of the major resident APC population in the respiratory tract (RT), class II MHC (Ia)-bearing dendritic cells (DC), is delayed relative to that in other tissues, and that both the intensity of Ia expression on these RTDC and their density within respiratory epithelia remain low until after weaning. The present study focuses on the functional capacity of neonatal RTDC and their responses to exogenous stimuli, and demonstrates that 1) infant Ia+ RTDC respond poorly to GM-CSF, under conditions that stimulate high levels of Ia expression and concomitant APC activity in adult cells; 2) both infant and adult RTDC contain a subpopulation of Ia- cells recognized by mAb OX62 that also respond poorly to GM-CSF; 3) inhalation of microbial stimuli or parenteral administration of IFN-gamma triggers rapid recruitment of DC into the airway epithelium and lung parenchyma of adults; this response is markedly attenuated in newborns and does not attain levels of competence until after weaning; and 4) endogenous macrophage-mediated suppression of the RTDC response to GM-CSF, the principal mechanism limiting in situ DC functional maturation in the adult lung, is highly active in the neonates. Taken together with earlier evidence of the relatively rapid postnatal development of T and B cell function in these animals, the present findings suggest that the sluggish performance of respiratory mucosal immune function(s) during infancy is attributable primarily to delayed maturation of local DC populations.

Hemorrhagic Shock-Induced Alterations in Circulating and Bronchoalveolar Macrophage Nitric Oxide Production

Local and systemic host immune functions are markedly altered after trauma. Activated macrophages (Mφ) are the major effector cells of protective immunity, mediated in part by nitric oxide (NO). This study was undertaken to determine the effects of hemorrhage (HEM) on Mφ cytotoxic function as measured by NO production. Male Sprague-Dawley 350- to 400-g rats were studied. Sham animals only had their carotid artery exposed and ligated. Hemorrhaged animals had carotid artery cannulation followed by HEM to SBP of 40 mmHg, sustained for 4.5 min, followed by resuscitation with shed blood and crystalloid. Recovered animals were sacrificed ( n = 5 each) at 6, 12, 24, and 72 hr after HEM; blood and alveolar Mφ were then isolated and examined. A monolayer of adherent Mφ was examined for NO production in resting state and after in vitro LPS stimulation. (1) HEM resulted in significantly reduced alveolar Mφ yield at 12 and 24 hr. (2) HEM increased NO production by circulating Mφ at 24 hr ( P < 0.05), while alveolar Mφ had significantly increased NO production at all time points after HEM ( P < 0.05). (3) LPS stimulation significantly increased NO production in both circulating and alveolar Mφ in sham animals and 6 hr after HEM but not at any other times. We therefore conclude that HEM causes early and prolonged activation of NO production by alveolar Mφ and delayed and brief activation of circulating Mφ. Alveolar and circulating Mφ are unable to significantly increase NO production in response to LPS stimulation during the later phases of HEM. These factors may alter host immune response differentially to local and systemic bacterial challenges after hemorrhage.

Prognostic significance of prostaglandin E2 production in fresh tissues of head and neck cancer patients.

Immunosuppressive prostaglandins may play a role in the biologic behavior of head and neck cancer. Increased levels of prostaglandin E2 (PGE2) have been measured in squamous cell carcinoma of the head and neck (SCCHN). To address this question, tissue levels of PGE2 were measured in tumor tissues, normal mucosa, and lymph nodes of 37 patients undergoing tumor resections. Tissue specimens were placed in culture media, and levels of PGE2 released into the supernatant were measured by radioimmunoassay. Tissue levels of PGE2 were significantly greater in tumor and normal mucosal tissues compared to lymph nodes (p = 0.0003). There was no difference between metastatic and tumor-free lymph nodes. Although tumor tissue levels of PGE2 were not associated with tumor stage, increased levels of PGE2 were associated with increased 2-year disease-free survival (p = 0.02). Although PGE2 may have adverse effects on local immune function in tumor tissues, improved survival of patients with increased local PGE2 production may be indicative of an enhanced immunologic response to the tumor which has a favorable impact on outcome.

A simple method for the propagation of cervical lymphocytes

Local immune function is most likely a key influence in the establishment of human papillomavirus infections and its subsequent disease. Unfortunately, little information is known about local cervical immunity, and even less is known about human papillomavirus immunoreactivity. In addition, studies of local immunoreactivity have been hampered by the technical difficulty in obtaining cervical lymphocytes. The objective of the present study was to develop a simple method for the propagation of cervical lymphocytes from biopsy-size specimens. Cervical tissue was obtained from women undergoing a hysterectomy. Cervical samples measuring approximately 3 by 5 by 2 mm were minced and divided into two portions. One portion was digested by standard digestion methods and density gradient lymphocyte separation. The sample was then immunocharacterized for CD4 and CD8 cells by flow cytometry. The other portion was minced into 1-mm3 sections, and each section was placed into a separate well with tissue culture medium and interleukin-2. Lymphocyte counts and immunophenotypic analysis were performed after 18 to 20 days in culture. After 18 to 20 days in culture, the analysis demonstrated that this method of direct lymphocyte culture from a biopsy specimen yielded approximately 1 x 10(6) to 5 x 10(6) lymphocytes. Immunophenotypic studies of the digested sample at day 0 revealed CD4-to-CD8 ratios of between 0.7:1 and 3.5:1, and at days 18 to 20 they revealed ratios of between 2.3:1 and 98:1. In summary, we developed a simple technique for propagating cervical lymphocytes from small tissue samples for the study of the local immune response. Studies are under way to optimize lymphocyte growth and to preserve CD8 populations.

A survey of the pattern of glandular distribution in the larynges of human infants.

We studied the development of glandular structures and the pattern of distribution of serous and mucous-type glands in the larynges of 77 human infants obtained at autopsy. The subglottic larynx was subjected to quantitative and qualitative analysis, using an image binarization procedure. The areas of mucosa and inner space of the subglottic larynx tended to increase with age. The area occupied by the glands differed considerably in younger infants and the areas of total glands and serous-type glands increased with age. There was no correlation between the area of the mucous glands and age. These findings indicate that local immune function of the secretory glandular system in the larynx of human infants increases with advancing age.

Role of the immune system in recovery from infection.

Infection is regarded as an imbalance between microbial pathogenicity factors and the host defense system. The virulence mechanisms include adhesion, chemotaxis, invasion, resistance and production of toxins. In addition, local and/or systemic immune functions in patients undergoing infections are altered. Nonspecific as well as specific cellular and humoral defense mechanisms are affected. The interaction of defined microbial pathogenicity factors with immune effector cells results in the activation of a variety of inflammatory mediators; they are a prerequisite for protective immunity but also induce local or systemic damage in the host when they occur in excessive amounts and when their metabolism is inadequately controlled. The analysis of the pathophysiological events during infection in patients by taking advantage of modern molecular and cell-biological methods may contribute to the development of novel therapeutic strategies.