The role of the superior parietal lobule in lexical processing of sign language: Insights from fMRI and TMS

There is strong evidence that neuronal bases for language processing are remarkably similar for sign and spoken languages. However, as meanings and linguistic structures of sign languages are coded in movement and space and decoded through vision, differences are also present, predominantly in occipitotemporal and parietal areas, such as superior parietal lobule (SPL). Whether the involvement of SPL reflects domain-general visuospatial attention or processes specific to sign language comprehension remains an open question. Here we conducted two experiments to investigate the role of SPL and the laterality of its engagement in sign language lexical processing. First, using unique longitudinal and between-group designs we mapped brain responses to sign language in hearing late learners and deaf signers. Second, using transcranial magnetic stimulation (TMS) in both groups we tested the behavioural relevance of SPL's engagement and its lateralisation during sign language comprehension. SPL activation in hearing participants was observed in the right hemisphere before and bilaterally after the sign language course. Additionally, after the course hearing learners exhibited greater activation in the occipital cortex and left SPL than deaf signers. TMS applied to the right SPL decreased accuracy in both hearing learners and deaf signers. Stimulation of the left SPL decreased accuracy only in hearing learners. Our results suggest that right SPL might be involved in visuospatial attention while left SPL might support phonological decoding of signs in non-proficient signers.

Energy-restricted Central-European diet stimulates liver microsomal function in obese postmenopausal women - a randomized nutritional trial with a comparison to energy-restricted Mediterranean diet

OBJECTIVE

Obesity and metabolic syndrome are risk factors for liver diseases like non-alcoholic fatty liver disease and non-alcoholic steatohepatitis. A healthy food pattern is vital for managing these health problems, therefore, this study investigated how two calorie-restricted diets, the Central European diet (CED) and Mediterranean diet (MED), altered microsomal liver function in obese postmenopausal women with a risk of metabolic syndrome.

PATIENTS AND METHODS

One-hundred-forty-four subjects were randomly assigned to the CED (n=72) or the MED (n=72) groups. A 13C-methacetin breath test was performed, before and after the intervention to assess CPDR (Cumulative Percentage Dose Recovery at 120 minutes of the test), TTP (Time to Peak - maximal momentary recovery of 13C) and Vmax (the maximum momentary 13C recovery).

RESULTS

There was a statistically significant increase in TTP and Vmax in the CED group only (p=0.0159 and p=0.0498, respectively). Changes in CPDR and TTP due to intervention were significantly higher in the CED group than in the MED group (p=0.0440 and p=0.0115, respectively).

CONCLUSIONS

This is the first study to document a stimulatory effect of the energy-restricted CED on liver microsomal function as compared to MED. The relatively short dietary intervention led to a significant difference in the CYP1A2 activity between groups. The trial was registered in the German Clinical Trials Register (DRKS-ID: DRKS00012958; URL: https://www.germanctr.de/).

Comparison of serum concentrations of environmental allergen-specific IgE in atopic and healthy (nonatopic) horses

Allergic responses in humans, horses and other species are mediated by immunoglobulin E (IgE) antibodies. Serum testing to detect allergen-specific IgE antibodies has been developed for dogs, cats and horses; this allows for the identification of allergens and determination of appropriate allergen- specific immunotherapies. This study compared serum allergen-specific IgE concentrations in atopic and healthy horses. The study was performed on Malopolski breed atopic (n=21) and nonatopic (n=21) clinically healthy horses. Allergen-specific IgE serum concentrations were measured in summer seasons of 2008-2015 using a monoclonal anti-IgE antibody. A Northern and Central European allergen panel containing mite, insect, mould and plant pollen allergens, including 15 tests of individual allergens and 5 tests of allergen mixtures was used. The mean allergen-specific IgE concentrations in the atopic and normal horse populations were compared. Among the atopic horses, the strongest positive reactions occurred against the storage mites Tyrophagus putrescentiae and the domestic mite Dermatophagoides farinae. The atopic horses also demonstrated high IgE concentrations against insects, particularly Tabanus sp., the plant pollens colza, cultivated rye and the mould pollen mixture Aspergillus/Penicillium. No horses in the atopic group were IgE-negative. Among all mite, insect, mould and some plant allergen groups the differences in mean specific IgE concentrations between allergic and healthy horses were significant. The mean IgE concentrations for most allergen groups were significantly higher in the atopic horses than in the healthy animals. However, a high incidence of positive reactions was observed in both healthy and allergic horses. Our results showed a high frequency of polysensitization in atopic horses.

Epidemiological Study of Canine Mast Cell Tumours According to the Histological Malignancy Grade

The aim of the study was to identify significant relationships between the tumour malignancy grade and dogs’ age, breed, sex, size, and location of mast cell tumours (MCTs). MCTs accounted for 13.27% of all diagnosed canine skin tumours. The highest incidence was recorded among Boxers, Labrador Retrievers, American Staffordshire Terriers, and Golden Retrievers. Statistical analysis revealed significantly higher probability of occurrence of the grade I mast cell tumour in the French Bulldog in the head, neck, torso, and limb regions, the grade-II mast cell tumour in Boxer, Doberman, Dachshund, shepherds, and setters in the scrotal region, and the grade III mast cell tumour in Shar-Pei in the axilla region. In the group of the oldest dogs aged 11-16, there was higher risk of development of MCTs grade II and III. Young dogs (aged 2-3 and 4-6) were found to be more prone to development of MCTs grade I. There was no correlation between MCTs grade and dogs’ sex and size. To the authors’ knowledge this is the first report on statistical relationships between the degree of mast cell tumour malignancy and dogs’ phenotypic traits, age and tumour location. This analysis indicate predilections for development of the particular mast cell tumour malignancy degrees in certain dog breeds, age, and anatomical location

Relationship between Total Homocysteine, Folic Acid, and Thyroid Hormones in Hypothyroid Dogs

Background

Both elevated homocysteine and decreased folic acid concentrations are observed in human patients with hypothyroidism and can influence the development of numerous secondary disorders.

Objectives

The aim of the study was to assess total homocysteine concentration in serum and to examine its relationship with the concentration of folic acid and thyroid hormones (tT4 and fT4).

Animals

Ten healthy and 19 hypothyroid client‐owned dogs.

Methods

Dogs with clinical signs of hypothyroidism had the diagnosis confirmed by additional tests. Total homocysteine, folic acid, total thyroxine, and free thyroxine concentrations in serum were evaluated.

Results

Hypothyroid dogs were diagnosed with increased homocysteine (median 22.20 μmol/L; range, 16.50–37.75) and decreased folic acid (median 20.62 nmol/L; range, 10.54–26.35) concentrations, as compared to healthy dogs (11.52 μmol/L; range, 10.00–16.65 and 30.68 nmol/L; range, 22.84–38.52, respectively). In sick dogs, total homocysteine was inversely correlated with folic acid (ρ = −0.47, P < 0.001), total thyroxine (ρ = −0.69, P = 0.0092), and free thyroxine (ρ = −0.56, P = 0.0302).

Conclusions

Hypothyroidism in dogs causes hyperhomocysteinemia. Concomitant mild folic acid decrease in hypothyroid dogs might be as a result of hyperhomocysteinemia.

The influence of non-specific anti-pruritus treatment with cyclosporine A on transepidermal water loss (TEWL) in natural atopic dermatitis in dogs

Atopic dermatitis is a common allergic skin disease in dogs. Monitoring the progress of treatment and the assessment of the severity of disease symptoms are crucial elements of the treatment procedure. One of the common means of assessing the severity of the clinical signs of the disease is the CADESI 03. Research studies have pointed to a possibility of assessing the severity of skin lesions by means of measuring biophysical skin parameters such as TEWL, skin hydration and erythema intensity. The aim of the study was the assessment of changes in TEWL and CADESI values measured in ten different body regions during non-specific anti-pruritus treatment. The examination was performed on ten dogs with atopic dermatitis (age from 2.5 years to 7 years, mean age 3.8 years). The measurements were performed in the following body regions: the lumbar region, the right axillary fossa, the right inguinal region, the ventral abdominal region, the right lateral thorax region, the internal surface of the auricle, interdigital region of the right forelimb, cheek, bridge of nose and the lateral site of antebrachum. A statistically significant decrease in CADESI values was reported starting from the second week of treatment. In the case of the mean TEWL values, a fall was observed after one week of treatment in the ventral abdominal region and the interdigital region, after two weeks of treatment in the axillary fossa and the inguinal region, and after three weeks in the cheek and the lateral thorax region. There was no statistically significant decrease in TEWL values in the course of treatment in four other regions.

Systemic and local effects of intragastric administration of the habanero fruit (Capsicum chinense Jacquin c.v.) in rats

The fruits of the habanero plant (Capsicum chinense Jacq.) are commonly used as spices. Their exceptionally hot flavour is the result of the substantial content of capsaicin that has among others the anticancer action. The experiments assess the impact of intragastric administration of a suspension of dried matter (dm) habanero fruit in peanut oil on the state of the digestive tract and parenchymal organs of rats. Habanero fruit with three different doses (0.08, 0.05 and 0.025 g of dry matter (d.m.) habanero fruit/kg b.w.) in 2 equal doses every 12 hours during 28 days was administered intragastrically in male rats. In day 8, 15 and 29 blood proofs were obtained to measure hematological parameters and alanine aminotransferase (ALT), aspartate aminotransferase (AST) activity, total bilirubin (BIL), total cholesterol (CHOL), glucose (GLUC), urea (U), and creatinine (CREA) content. Internal organs of rats were examined anatomopathologically. Between the study groups and control group there were no statistically significant differences in studied parameters. Post-mortem examinations as well as histological findings showed no pathological changes in the organs of rats. The study demonstrated a high level safety of the fruit habanero (Capsicum chinense Jacq.) administration in rats. There were no hematological, biochemical or post-mortem changes at doses that due to the amount of capsaicin can exhibit antitumor properties.

Non-invasive detection of Helicobacter pylori in cystic fibrosis--the fecal test vs. the urea breath test

OBJECTIVES

Only recently it has been proven that cystic fibrosis (CF) patients have the same prevalence of Helicobacter pylori (HP infection) as the general population, as well as the same spectrum of changes caused by this pathogen. The aim of this study was to assess the reliability of the two most popular noninvasive tests--the urea breath test (UBT) and the fecal test (FT) in diagnosing HP infection in CF patients.

PATIENTS AND METHODS

The study was conducted on 79 CF patients and 49 healthy subjects (HS). The presence of HP infection was evaluated using the 13C isotope-labeled urea breath test and the fecal test (ELISA).

RESULTS

Fifteen (19.0%) CF patients and eight (16.3%) HS were found to be HP positive using the UBT. The HP stool antigen was detected in twelve (15.2%) CF patients and seven (14.3%) HS. Discordant results for the two tests were obtained in 9 out of 18 (50.0%) CF patients and 3 out of 9 (33.3%) HS. Although the differences were not statistically significant, the risk of potentially false negative and false positive results in CF subjects seems to be high. Similarly, no statistical differences in the basic clinical parameters were documented between the CF subgroups with concordant and divergent HP results.

CONCLUSIONS

Since there is convincing evidence of divergent UBT and FT results in the CF patients, we suggest that UBT is kept as the standard method for HP detection in this population, at least until obtaining reliable and valid results allows for a change in such an approach.

Parenteral nutrition in patients with inborn errors of metabolism - a therapeutic problem

Parenteral nutrition is now a standard part of supportive treatment in pediatric departments. We describe four cases in which parenteral nutrition was extremely difficult due to coincidence with inborn errors of metabolism. The first two cases was fatty acid beta-oxidation disorders associated with necrotizing enterocolitis and congenital heart disease. Thus, limitations of intravenous lipid intake made it difficult to maintain a good nutritional status. The third case was phenylketonuria associated with a facial region tumour (rhabdomyosarcoma), in which parenteral nutrition was complicated because of a high phenylalanine content in the amino acid formulas for parenteral nutrition. The fourth patient was a child with late-diagnosed tyrosinemia type 1, complicated with encephalopathy - during intensive care treatment the patient needed nutritional support, including parenteral nutrition - we observed amino acid formula problems similar to those in the phenylketonuria patient. Parenteral nutrition in children with inborn errors of metabolism is a rare, but very important therapeutic problem. Total parenteral nutrition formulas are not prepared for this group of diseases.

Synthesis of β-damascone derivatives with a lactone ring and their feeding deterrent activity against aphids and lesser mealworms

We report the chemical modification of β-damascone (1) into new lactone derivatives and their biological activity towards aphids and lesser mealworms.

Participation of iNKT cells in the early and late components of Tc1-mediated DNFB contact sensitivity: cooperative role of γδ-T cells

Prior studies of classical 24 h responses in TNP-Cl (picryl chloride) allergic contact sensitivity (CS), showed mediation by Th1 cells in CBA mice, and established that 24 h elicitation of responses requires an early 2 h CS-initiating component dependent on iNKT cells, IL-4 and B-1 B cells. Here, we studied the other form of cytotoxic T cell (Tc1) CS in DNFB sensitized BALB/c mice and determined that similar CS-initiation also is required. We systematically tested each step of the initiation pathway in this model. Thus, DNFB Tc1 CS was significantly impaired in iNKT cell deficient CD1d(-/-) and Jα18(-/-) mice, IL4Rα(-/-) and STAT-6(-/-) mice, and also in pan B-cell deficient JH(-/-) mice. Further, the Tc1 DNFB CS-initiating component, like Th1 response to TNP-Cl, was elicited by only 1-day after immunization, due to B-1 cells. In summary, we show that CS-Initiation also is required in Tc1 CS. Further, we have newly determined regulatory support of both the early and late components of DNFB induced Tc1 CS by iNKT cells and γδ-T cells. In summary, both iNKT cells and assisting γδ-T cells are involved in initiating and effector phases of DNFB induced CS.

Evaluation of a human generic formulation of ciclosporin in the treatment of canine atopic dermatitis with in vitro assessment of the functional capacity of phagocytic cells

To compare the efficacy, tolerability and safety of a generic formulation of ciclosporin for human beings with prednisone in the treatment of canine atopic dermatitis), human generic ciclosporin A (hgCsA) (5 mg/kg daily) and prednisone (1 mg/kg daily for seven days, followed by 1 mg/kg every second day) were administered to 13 and seven dogs with atopic dermatitis, respectively, for 42 days. Skin changes were assessed using a modified canine atopic dermatitis extent and severity index (mCADESI-01) and a pruritus intensity scale system. The in vitro functional capacity of phagocytic cells was assessed using the tetrazolium reductase activity and zymosan-stimulated tetrazolium reductase activity tests, as well as measurements of the percentage phagocytic activity and the ingestion capacity of phagocytic cells. Haematological and biochemical parameters were also monitored. There was a greater than or equal to 50 per cent reduction from the baseline in mCADESI-01 scores in 84.6 and 100 per cent of dogs, and a greater than or equal to 50 per cent reduction from the baseline in pruritus scores in 76.9 and 85.7 per cent of dogs, treated with hgCsA and prednisone, respectively. No important adverse physical, haematological or biochemical effects occurred with either drug and no statistically significant changes were detected in any of the four tests assessing the functional activity of phagocytes. The generic formulation of ciclosporin was effective in reducing the severity of physical signs of canine atopic dermatitis and was well tolerated.

Mechanisms of immunological tolerance to the antigens of the central nervous system. Skin-induced tolerance as a new therapeutic concept

The immune system is designed to recognize and eliminate foreign (non-self) antigens. At the same time, there are mechanisms protecting the organism from development of inappropriate immune responses that are harmful to ones own body (allergy, autoimmunity) and those that help to silence the inflammatory responses and allow their resolution. Tolerance to self-antigens is a result of central tolerance (negative selection) and various mechanisms of peripheral tolerance that include anatomical sequestration of self-antigens, deletion of peripheral autoreactive lymphocytes, the development of lymphocyte functional unresponsiveness and action of T regulatory (Treg) cells. This article summarizes current knowledge about mechanisms of immunological tolerance that protect from development of immune responses to self-antigens present in the central nervous system (CNS). Finally, it discusses the subject of skin-induced tolerance as demonstrated in an animal model of autoimmune disease of the CNS, experimental autoimmune encephalomyelitis (EAE). The potential clinical use of this approach to regulate disease will be discussed.

Motor coordination assessment in practicing surgeons and medical students

INTRODUCTION

Manual and motor coordination skills are commonly believed to be necessary for the surgical profession.

AIM OF STUDY

To assess motor coordination skills in medical students, surgical residents and attending surgeons.

MATERIAL AND METHODS

The study group consisted of 17 surgeons and 44 medical students. All participants were tested with a number of tests for motor coordination. Statistical analysis with ANOVA/MANOVA methods, contrast analysis and post-hoc test as appropriate.

RESULTS

There were no gender related differences in coordination skills. The group of students had significantly lower results in comparison to surgeons. Statistical significance (p < 0.05) was observed in perception diversity test, and Perception-Diversity-Orientation Index. There was no statistically significant difference between residents and attending surgeons

CONCLUSION

Our results demonstrated that coordination skills are not related to gender. They may serve as one of the selection criteria to surgical profession. The level of coordination skills is helpful in designing of individual training program.

Melatonin and its influence on immune system

Melatonin was initially extracted from the pineal gland and was thought to be produced exclusively by this organ. Subsequently it was shown that melatonin is also produced in other tissues including the gastrointestinal tract, retina and cells of the immune system. Melatonin is believed to be an important regulator of circadian and seasonal rhythms. Over the last thirty years, a great number of reports have documented a relationship between melatonin/pineal gland and the immune system in various species, including humans. In this review, current knowledge about the role of melatonin in the regulation of immune responses will be discussed.

Influence of melatonin and its precursor L-tryptophan on Th1 dependent contact hypersensitivity

There is strong evidence that melatonin possesses immunomodulatory activity. It has been shown that it enhances the immune response, acting as a pro-inflammatory agent. It is suggested that melatonin promotes Th1-mediated immune responses by upregulating IL-12 production by antigen presenting cells. In contrast, it has also been shown that melatonin can inhibit Th1 immunity and instead promote a Th2 response. This discrepancy between different observations of the regulatory activity of melatonin on Th1 immunity encouraged us to further investigate the influence of melatonin and its precursor L-tryptophan on Th1 mediated contact hypersensitivity (CHS). Our results show that both melatonin and L-tryptophan inhibit the inflammatory response associated with CHS. Melatonin inhibited the Th1-dependent immune response by suppressing the production of IFN-gamma and IL-12 by cells in the lymph node. On the other hand treatment with L-tryptophan inhibits CHS without affecting INF-gamma production by Th1 effector cells. Observed suppression of CHS after L-tryptophan treatment is at least partly through the production of the anti-inflammatory cytokine IL-10.

Different defense strategies of Dendrolimus pini, Galleria mellonella, and Calliphora vicina against fungal infection

The resistance of Galleria mellonella, Dendrolimus pini, and Calliphora vicina larvae against infection by the enthomopathogen Conidiobolus coronatus was shown to vary among the studied species. Exposure of both G. mellonella and D. pini larvae to the fungus resulted in rapid insect death, while all the C. vicina larvae remained unharmed. Microscopic studies revealed diverse responses of the three species to the fungal pathogen: (1) the body cavities of D. pini larvae were completely overgrown by fungal hyphae, with no signs of hemocyte response, (2) infected G. mellonella larvae formed melanotic capsules surrounding the fungal pathogen, and (3) the conidia of C. coronatus did not germinate on the cuticle of C. vicina larvae. The in vitro study on the degradation of the insect cuticle by proteases secreted by C. coronatus revealed that the G. mellonella cuticle degraded at the highest rate. The antiproteolytic capacities of insect hemolymph against fungal proteases correlated well with the insects' susceptibility to fungal infection. The antiproteolytic capacities of insect hemolymph against fungal proteases correlated well with the insects' susceptibility to fungal infection. Of all the tested species, only plasmatocytes exhibited phagocytic potential. Exposure to the fungal pathogen resulted in elevated phagocytic activity, found to be the highest in the infected G. mellonella. The incubation of insect hemolymph with fungal conidia and hyphae revealed diverse reactions of hemocytes of the studied insect species. The encapsulation potential of D. pini hemocytes was low. Hemocytes of G. mellonella showed a high ability to attach and encapsulate fungal structures. Incubation of C. vicina hemolymph with C. coronatus did not result in any hemocytic response. Phenoloxidase (PO) activity was found to be highest in D. pini hemolymph, moderate in G. mellonella, and lowest in the hemolymph of C. vicina. Fungal infection resulted in a significant decrease of PO activity in G. mellonela larvae, while that in the larvae of D. pini remained unchanged. PO activity in C. vicina exposed to fungus slightly increased. The lysozyme-like activity increased in the plasma of all three insect species after contact with the fungal pathogen. Anti E. coli activity was detected neither in control nor in infected D. pini larvae. No detectable anti E. coli activity was found in the control larvae of G. mellonella; however, its exposure to C. coronatus resulted in an increase in the activity to detectable level. In the case of C. vicina exposure to the fungus, the anti E. coli activity was significantly higher than in control larvae. The defense mechanisms of D. pini (species of economic importance in Europe) are presented for the first time.

Interplay between Helicobacter pylori and the immune system. Clinical implications

Helicobacter pylori (H. pylori) is a gram-negative bacteria infecting more than 50% of human population. H. pylori selectively colonizes gastric mucosa and represents the major cause of gastroduodenal pathologies, such as gastric ulcer, autoimmune gastritis, gastric cancer and B cell lymphoma of mucosa associated lymphoid tissue (MALT). In this review interplay between H. pylori and both innate and adaptive immune responses is discussed. The second part of this article presents current knowledge about the relationship between H. pylori infection and neoplasia.

The influence of collagenase treatment on the production of TNF-α, IL-6 and IL-10 by testicular macrophages

Testicular macrophages (TMf) are located in the interstitial tissue of the male gonad. Highly purified TMf populations can be prepared either by the mechanical shaking of dispersed testicular tissues or by enzymatic digestion with collagenase followed by cell adherence, rosetting and gradient centrifugation. TMf obtained by the enzymatic procedure produced significantly more cytokines (IL-6, IL-10 and TNF-alpha) than TMf isolated by the mechanical method and this effect is long-lasting. Our results indicate that isolation of tissue macrophages by enzymatic digestion may influence their functional activity, and suggest that critical evaluation of the method used to obtain these cells should be the regular practice.

Modulation of Macrophage Activity by Proteolytic Enzymes. Differential Regulation of IL-6 and Reactive Oxygen Intermediates (ROIs) Synthesis as a Possible Homeostatic Mechanism in the Control of Inflammation

Inflammatory foci are rich in proteases released by neutrophils (serine proteases) and macrophages (metalloproteases). These enzymes can degrade extracellular matrix proteins and cell membrane bound proteins thus contributing to the development and progression of inflammatory reaction. In this study we have investigated the influence of collagenase (metalloprotease) and trypsin (serine protease) on murine resident and oil-induced peritoneal macrophages (Mf). Short in vitro treatment of Mf, not affecting cell viability, significantly reduced the release of reactive oxygen intermediates (ROIs) and at the same time triggered the increase of IL-6 production and to lesser extent of TNF-alpha production. Both these effects were dependent on enzyme concentration used and were particularly well pronounced in resident macrophages. In addition both enzymes cleaved a number of cell-membrane molecules, including CD23, CD14, CD95L, and Mac-3. We hypothesize that the enzymatic digestion of certain Mf surface receptor proteins in inflammatory foci may be responsible for modification of cell behaviour either by preventing the generation of specific signal or alternatively by delivering a mock substitute signal to the cell interior. In effect inhibition of ROIs production limits their destructive effects and the increase in the secretion of IL-6 stimulates the synthesis of acute phase proteins and triggers other anti-inflammatory mechanisms thus directing Mf present in inflammatory foci into regulatory pathway rather than allowing them to perform solely the effector function.

Cross-reactivity of TNP immune effector T cells that mediate contact hypersensitivity and inflammatory bowel disease in the mouse

BACKGROUND

Experiments were aimed to test the cross-reactivity of immune Th1 cells that mediate contact hypersensitivity (CHS) or inflammatory bowel disease (IBD) to TNP in the mouse.

METHODS

CBA/J mice were immunized either epicutaneously or intrarectally with TNP and after appropriate time intervals were challenged with antigen in a crossed manner. The CHS reaction was measured by the ear swelling test. IBD was quantified by increase of colon weight and myeloperoxidase level. Both reactions were confirmed histologically. In passive-transfer experiments, mesenteric lymph node cells of animals sensitized intrarectally and peripheral lymph node and spleen cells of mice immunized epicutaneously were used. In some experiments, before being immunized mice were made either unresponsive to the TNP hapten by induction of suppressor T cells, or resistant to suppression after induction of upregulatory T cells.

RESULTS

Irrespective of the mode of sensitization upon appropriate challenge with antigen all mice developed a good CHS reaction as well as significant IBD. This cross-reactivity could be passively transferred by immune cells. In mice in which antigen-specific down- or upregulatory cells were induced before sensitization both CHS and IBD to TNP were modulated accordingly.

CONCLUSION

TNP hapten deposited on skin or on mucosal surfaces induces effector cells that recognize antigen independent of its tissue localization, and produce a local inflammatory reaction. TNP-specific up- and downregulatory cells, shown before to regulate the CHS reaction, similarly modulate the generation and development of hapten-induced IBD.

[Chronic inflammation of the colon: a diagnostic problem]

Chronic inflammation of the colon and rectum with associated diarrhea has become more difficult to diagnose recently. Many etiological factors and different therapeutic outlines need to be carefully discussed and summarized. Based on most recent literature, authors present current data on etiology and specific (case-depended) diagnostic procedures in colitis and proctocolitis.

IL-12 reverses established tolerance mediated by TCRalphabeta+ but not by TCRgammadelta+ suppressor T cells

Topical cutaneous painting with chemically reactive haptens induces the ability to subsequently elicit contact sensitivity (CS) responses in the skin. These CS responses are in vivo examples of acquired, antigen (Ag)-specific T cell immunity, and are a form of delayed-type hypersensitivity (DTH). In contrast, high dose i.v. administration of the hapten can induce Ag-specific tolerance. In some instances this specific immune hyporeactivity is due to suppressor T cells. We investigated the effect of IL-12 on reversal of tolerance due to suppressor T cells that were induced by i.v. administration of hapten in either normal TCRalpha+/+, or in immunodeficient TCRalpha-/- mice. In the TCRalpha+/+ mice, tolerance is mediated by TCRalphabeta+ suppressor T cells, while in the TCRalpha-/- mice the tolerance is due to suppressive TCRgammadelta+ cells. Treatment with IL-12 reversed suppressor mediated by the TCRalphabeta+ cells, but did not affect tolerance due to TCRgammadelta+ suppressor cells. Another difference was that the alphabetaTCR+ suppressor cells produced a soluble suppressor factor that could replace the surppressor cells, while gammadeltaTCR+ suppressor cells did not. We hypothesized that IL-12 may strengthen responses of target CS-effector T cells influenced by the hapten-MHC-specificity of alphabeta suppresssor cells, or suppressor factor. On the other hand, gammadeltaTCR+ suppressive cells likely have specificity for the hapten alone, and are not MHC-restricted, and therefore probably do not operate via peptide-MHC interactions, that could be strengthened by IL-12. The ability of IL-12 to strengthen the resistance of CS-effector T cells to alphabeta TCR suppressor cells, may be due to the ability of IL-12 to increase T cell costimulation mediated by signaling mechanisms acting via B7.1 and B7.2. In contrast, gammadeltaTCR+ suppressor cells, that are largely hapten-specific, probably do not interact with peptide/MHC complexes on APC, and thus are not affected by IL-12 strengthening of co-stimulation.

Experimental inflammatory bowel disease--role of T cells

BACKGROUND

Our experiments were aimed to test: 1. which lymphocyte subpopulations participate in mouse colitis, produced by intrarectal (i.r.) deposition of trinitrobenzene sulphonic acid (TNBSA, TNP hapten); 2. the expression of cell adhesion molecules on lymphocytes draining the site of reaction; 3. the influence of mouse haplotype on the development of colitis.

METHODS

CBA/J, BALB/c and C57BI/6 inbred and outbred Swiss Webster strains were used. Mesentheric lymph node (MLN) cells of immunized animals, unseparated or separated into CD4+, CD8+ or gammadelta+ and alphabeta+ T cell subpopulations or depleted of B lymphocytes, were transferred into recipients which were challenged i.r. with TNBSA. Inflammatory reaction in the colon was confirmed macro- and microscopically and by myeloperoxidase (MPO) level. MLN lymphocyte surface markers were tested cytofluorimetrically using appropriate antibodies.

RESULTS

Sensitization with TNP results in chronic colitis (hapten dose-dependent colon weight gain and cellular infiltrate, significant increase of MPO level) only in CBA/J and BALB/c strains and can be adoptively transferred in a cell-dose dependent manner into syngeneic recipients by T alphabeta+ cells of both CD4+ and CD8+ subpopulations. T gammadelta+ cells were ineffective and B lymphocytes do not participate in the passive transfer reaction. In MLN the number of T lymphocytes positive for cell adhesion molecules particularly LPAM-1 (V-CAM1) and LPAM-2 increases significantly.

CONCLUSIONS

Both CD4+ and CD8+ lymphocytes participate in the development of TNP-induced colitis. High MPO level may suggests that both Th1 and Th2 cells are involved. Colitis is accompanied by a significant accumulation in MLN of T lymphocytes positive for several cell surface adhesion molecules characteristic for memory T cells. Significant differences in susceptibility to develop colitis were found between different strains of mice.

Heat-aggregated immunoglobulins increase in vivo immunogenicity of mouse hapten (TNP)-derivatized macrophages by upregulation of interleukin-12 secretion and expression of B7-1 and B7-2 costimulatory molecules

Antigen-antibody complexes (IC) can up or down regulate immune responses by induction of immunoregulatory cells. We have studied the effect of mouse heat-aggregated immunoglobulin (Ig) (HA) which have many biological activities similar to IC on immunogenicity of TNP-substituted macrophages (TNP-Mphi). Our results show that: (1) mouse oil-induced peritoneal macrophages treated with HA produce in vitro significantly higher levels of interleukin (IL-1beta), tumor necrosis factor (TNF)-alpha, IL-6, IL-10 and particularly IL-12 and express more B7-1 and B7-2 and ICAM-1 cell surface costimulatory molecules than Mphi treated with monomeric Ig (MM); (2) Mphi derivatized with TNP, treated or not with MM, induce in vivo antigen-specific unresponsiveness. In contrast TNP-Mphi treated with HA induce significant contact sensitivity reaction even when injected into previously tolerized recipient animals. Treatment of recipients with anti-IL-12 Ab prevents immunization by TNP-Mphi-HA. These results indicate that bypass of tolerance by treatment of TNP-Mphi with HA is a result of an increased production of IL-12 by these cells and an enhanced expression of costimulatory molecules important in T cell-Mphi interactions. We suggest that a similar overcoming of tolerance through the action of IC may be responsible for the generation of autoantibodies of heterologous specificity in pathological conditions in which such complexes are formed.

Soluble T cell receptors modulate cytokine production and oxygen metabolism by peritoneal macrophages

Preincubation of peritoneal macrophages and their subsequent culture with recombinant soluble T cell receptor (sTCR) results in significant increase of: TNF-alpha, IL-1beta, IL-6, IL-10, IL-12 production and nitric oxide (NO) synthesis and this phenomenon was dose dependent. Moreover, treatment of macrophages with sTCR showed two to three fold increase of luminol dependent chemiluminescence (LCL) when compared to untreated macrophages (Mf). In contrast, in our study we did not find any influence of sTCR on co-stimulatory (B7.1 and B7.2), adhesion molecule (ICAM-1) or FcRII/III expression by macrophages. However, macrophages treated with control supernatants received after phosphatidylinositol-specific phospholipase C (PI-PLC) treatment of BW1100 cells or thymocytes termed s-BW or s-Th did not influence their biological activity.

IL-12 is produced by antigen-presenting cells stimulated with soluble alphabeta TCR and restores impaired T(h)1 responses

Contact sensitivity (CS) is a cutaneous T(h)1 response that is induced by skin painting with reactive hapten. In prior in vivo studies of CS, we showed that recombinant soluble alphabetaTCR (sTCR) acted non-specifically to protect CS-effector T cells from suppression, but no molecular mechanism was determined. In the current study, we employed an in vitro system to investigate the mechanism of how sTCR protect CS-effector T cells from suppression. Immune CS-effector cells and appropriate hapten-conjugated antigen-presenting cells (APC) were incubated together with down-regulatory culture supernatant produced by suppressive spleen cells from mice tolerized i.v. with specific hapten, which produced strong inhibition of IFN-gamma production by the CS-effector cells. Importantly, addition of two different sTCR, of unrelated specificity, reversed this down-regulation and thus restored IFN-gamma production. We found that the APC, and not the CS-effector T cells, were the locus of the sTCR-mediated protection and showed direct binding of sTCR to APC by flow cytometry. Further, addition of anti-IL-12 showed that sTCR protection was due to IL-12 induced by sTCR and released by the APC, and was confirmed by ELISA measurement of IL-12 induced in APC supernatants by sTCR incubation. These results indicated a possible new regulatory loop in which suppression was reversed by IL-12 derived from APC, following direct surface binding of sTCR, and enhanced by IFN-gamma production from the T(h)1 CS-effector cells.

[Regulation of the contact sensitivity reaction by suppression of T gamma delta lymphocytes]

Contact sensitivity (CS) is a classical example of in vivo T cell mediated immune response that is under regulation. It is well known that in normal mice suppression of CS can be mediated by T alpha beta cells tolerized by prior exposure to high dose of antigen (Ag). In this paper it was shown that treatment of defective TCR alpha -/- or TCR beta -/- mice with high dose of Ag may result in induction of T gamma delta suppressor cells, that are able to inhibit both adoptive cell transfer of CS in vivo and IFN-gamma production in vitro. These suppressor cells are characterized as: TCR gamma delta+, CD3+, CD4-, CD8-, CD28+, CD40L+, CD95 (Fas)+, Fc gamma R+ and NK1.1-. Suppression mediated by T gamma delta cells showed antigen specificity, but was not restricted by the MHC. T gamma delta suppressor cells express very strong down-regulatory activity where even 2.5 x 10(3) T gamma delta cells could suppress 7 x 10(7) CS-effector cells. Presented data may suggest that IL-4 released by T gamma delta suppressor cells is involved in the mechanism of their down-regulatory function.

Role of interleukin-4 in down-regulation of contact sensitivity by gammadelta T cells from tolerized T-cell receptor alpha-/- mice

Contact sensitivity (CS) is a classical example of an in vivo T-cell-mediated immune response that is under regulation. Such down-regulation can be mediated by alphabeta T cells in mice that are tolerized by prior exposure to high doses of antigen. In contrast, we demonstrated previously that such high-dose antigen tolerance in T-cell receptor (TCR) alpha-/- H-2d mice induced antigen-specific, apparently major histocompatibility complex-unrestricted, CD4- CD8- gammadelta T cells, that also could down-regulate CS responses antigen-specifically in vivo, and also inhibited in vitro production of IFN-gamma. In the present experiments we employed H-2b-deficient TCRalpha-/- and TCRbeta-/- mice, owing to different molecular constructs than were used previously, and confirmed that tolerized gammadelta T cells in these different H-2b alphabeta TCR-/- mice down-regulated CS. Thus, gammadelta T-cell suppressor function was not limited to mice bearing a special transgenic TCRalpha-/- DNA construct. Furthermore, employing monoclonal antibody and complement depletion in vitro and adoptive transfer in vivo, characterized the phenotype of these gammadelta down-regulatory T cells as: CD3+, CD28+, CD40-ligand+, Fas+, FcgammaR+ and NK1.1-. Also, in vitro antigen desensitization of these trinitrophenyl (TNP)-specific TCRgammadelta+ down-regulatory cells was achieved with soluble TNP-bovine serum albumin (BSA), but not with oxazolone-BSA, showing that these suppressive gammadelta T cells have antigen-specific receptors. Moreover, employing monoclonal antibody blocking of gammadelta suppressors in vitro, and of recipients in vivo, we showed that interleukin-4 (IL-4) was involved in this down-regulation of CS by gammadelta T cells, while IL-10 and transforming growth factor-beta2 were not. In summary, generation of antigen-specific, double-negative, gammadelta suppressor cells, by tolerance of high antigen doses in TCRalpha-/- mice, appears to be a general phenomenon, and IL-4 production is involved in their down-regulation of the T helper type 1 cells that mediate CS.

[Defense mechanisms in the peritoneum]

There are many specialised defence mechanisms connected with immunity of peritoneal cavity. These are absorbtion of bacteria and their toxins from peritoneum, phagocytosis, opsonization, activation of the complement and separation of infection in the peritoneal cavity. A very important role in defence mechanisms of peritoneal cavity play GALT and PALT. Among many cells of the immune system mastocytes and gamma delta T cells have important role in induction and regulation of immune mechanisms in the peritoneal cavity. Lymphocytes T gamma delta release many cytokines and chemokines what allows them to play their protecting role during peritonitis. Released cytokines (especially IFN-gamma) activate macrophages to produce and secret many proinflammatory cytokines and factors. On the other hand mast cells play their role in defence of peritoneal cavity via TNF-alpha and histamine release and inhibition of fibrynolysis.

[Immunogerontology--aging of the immune system and its cause]

Ageing is characterized by declining ability of the individual to adapt to environmental stress. By most parameters tested either in the laboratory or in vivo, immune function is decreased in elderly compared with young individuals. First age-associated changes in the immune system appear at the time of sexual maturity and result in the thymus atrophy. However, more drastic decrease of circulating T lymphocytes is observed in people over 70. Moreover, T cells respond weaker to mitogens, produce lower level of cytokines and cytokine receptors e.g. IL-2, IL-2R. Observed decrease of CD8+ T cells (T cytotoxic & T suppressor cells) results in an increase of CD4/CD8 ratio. Additionally, ageing also affects humoral response what consists in decrease in antibody producing cell number. Moreover, elderly individuals show increased level of serum IgG and IgA with parallel decrease of IgM. Seniors possess increased level of auto-antibodies and auto-anti-idiotopic antibodies. Innate immune responses are less affected with age. Adherence and phagocytosis of polymorphonuclears and macrophages is unchanged or even increased. However, their chemotaxis and synthesis of reactive oxygen metabolites is decreased. Reduced immunological vigor may result in the high incidence of infectious diseases, autoimmune diseases, immune complex diseases, and cancer.

Cross-talk between gammadelta T lymphocytes and immune cells in humoral response

The role of gamma delta T cells in immunoregulation is largely unknown. In the current study we noted that gamma delta T cells play a positive role in the humoral response. These positively acting gamma delta T cells are required for the successful adoptive cell transfer of the humoral response, as well as for in vitro generation of plaque-forming cells (PFC). The presented results show that gammadelta T cells cause an increase in interleukin-10 (IL-10) production, which partly elucidates the mechanism of action of these cells. However, experiments with cell culture inserts strongly suggest that direct cell-cell contact between immune and gamma delta H-2-compatible regulatory T cells is critical to the exertion of the positive immunoregulatory function of gamma delta cells. The mechanism of cross-talk between these two cell populations is still not clear but we regard as most likely that the positively acting gamma delta T cells may interact with a complex of heat-shock protein-non-polymorphic MHC (IB) on the surface of T helper type 2 and/or B cells. This could provide, by direct cell-cell contact, the cognate recognition between gamma delta T-cell receptors and heat-shock protein-MHC that leads to positive internal signalling in the immune cells.

IL-12 reverses established antigen-specific tolerance of contact sensitivity by affecting costimulatory molecules B7-1 (CD80) and B7-2 (CD86)

Cutaneous painting with reactive haptens induces contact sensitivity (CS) responses that are in vivo examples of T cell immunity. In contrast, high dose i.v. administration of the hapten can induce tolerance. We investigated the effect of IL-12 on reversal of this tolerance and attempted to determine in vitro the mechanism of this reversing effect by measuring proliferation and IFN-gamma production by CS effector T cells stimulated with hapten-conjugated APC, and we also measured CS ear swelling in vivo. The in vitro responses of T cells to hapten-APC became absent in tolerized mice, paralleling impaired in vivo CS responses. Addition of IL-12 to cultures manifesting this fully established in vitro tolerance completely restored impaired responses of tolerized T cells. The reversing effects of IL-12 were not blocked by anti-IFN-gamma mAb, but were blocked by mAbs against B7-1, more strongly by anti-B7-2, and by both Abs together. Additional in vivo ear-swelling response experiments confirmed the reversing effects of IL-12 on established tolerance. To examine whether the IL-12 effect depended on stimulation of IFN-gamma, we directly injected IFN-gamma into tolerized mice. This partially mimicked but did not fully reconstitute the effects of IL-12. In summary, IL-12 abrogation of established tolerance of CS may have been partially due to endogenous production of IFN-gamma, but appeared mainly due to direct activation of the tolerized T cells by affecting signaling through costimulatory molecules B7-1 and B7-2.

[Colitis in laboratory experimentation]

Immunological concept of pathogenesis of inflammatory bowel disease (ulcerative colitis and Crohn's disease) is presently most common but it's specific etiology is still unknown. Spontaneous manifestations of these disease in animal are very rare and ad adequate laboratory animal model is needed for research. In this review different animal models of colitis are present in chronological order, displaying the search for the highest similarity to the clinical colitis.

Positive regulatory gamma delta T cells in contact sensitivity: augmented responses by in vivo treatment with anti-gamma delta monoclonal antibody, or anti-V gamma 5 or V delta 4

Contact sensitivity (CS) responses, induced by skin painting with reactive haptens like picryl chloride or oxazolone, are classical examples of in vivo immunity mediated by alpha beta T cells. Our previous studies showed that gamma delta T cells were required to assist the alpha beta CS-effector T cells in the successful adoptive cell transfer of CS responses. These spleen and lymph node-derived gamma delta+ CS-assisting regulatory cells were CD3+, CD4-CD8+, non-antigen-specific, and non-MHC-restricted, and preferentially expressed V gamma 5 and V delta 4 variable regions. In the current study we show that systemic treatment of mice in vivo with anti-gamma delta mAb, produced a similar positive influence on CS responses in two different systems: i.e. active sensitization, or adoptive cell transfer. In addition to augmented CS responses produced by treatment with pan anti-gamma delta TCR mAb, anti-gamma delta-V region mAb were examined, and augmentation of CS also was produced by anti-V gamma 5 and anti-V delta 4 mAb, the V regions determined previously to be preferentially expressed on gamma delta CS-assisting cells. We speculate that the positive influence of anti-gamma delta mAb was not caused by quantitative changes in gamma delta T cells, because FACS studies demonstrated a lack of in vivo depletion of peripheral blood and lymphoid gamma delta T cells, and also no depletion of epidermal dendritic gamma delta T cells (DETC), in mice treated with anti-gamma delta TCR mAb. Instead, our data favor the hypothesis that CS-assisting gamma delta T cells can be activated in vivo by anti-gamma delta TCR mAb interacting with their gamma delta TCR, at least with the short term protocols we employed, resulting in augmentation of CS responses perhaps by releasing positively-acting factors, such as certain cytokines.

Different patterns of gamma delta and alpha beta T cell redistribution in the mouse after partial gastrectomy

BACKGROUND

Stress, including surgical trauma, results in different dysfunctions of the body. In our former experiments on posttraumatic modification of immune response of gastrectomized mice we observed a significant suppression of contact sensitivity. This could be transferred by lymph nodes and spleen T lymphocytes of mice which underwent surgery.

MATERIALS AND METHODS

We studied changes in gammadelta and alphabeta T cell numbers in peripheral blood, Peyer's patches, and mesenteric lymph nodes after partial gastrectomy (major operation) and after sham gastrectomy (laparotomy-minor operation) in mice. The number of gammadelta and alphabeta T cells was counted on the FACSTAR cell sorter before and 1, 2, 3, 7, and 14 days after surgery.

RESULTS

In our observations there was a significant increase of percentage of gammadelta T cells both in Peyer's patches (1.9 +/- 0.5 to 10.5 +/- 0.3) and in mesenteric lymph nodes (2.7 +/- 0.7 to 8.8 +/- 3.5) on the third day after partial gastrectomy (546 and 322% of control values, respectively). In contrast in gastrectomized mice the number of alphabeta T cells in Peyer's patches (38.4 +/- 6.8 to 21.2 +/- 6.2) and lymph nodes (56.7 +/- 15 to 40.4 +/- 17) was decreased on day 3 (55 and 71% of control values, respectively). There was a decline in both alphabeta (18.1 +/- 8 to 8.2 +/- 1.7) and gammadelta (6.7 +/- 2.8 to 3.9 +/- 2) T cell numbers in peripheral blood on days 1, 3, and 7 (45 and 58% of normal values, respectively). Sham operation had no significant influence on alphabeta and gammadelta T cell numbers. We observed that after leg amputation the number of gammadelta T cells in mesenteric lymph nodes was significantly increased on day 3 (0.8 +/- 0.2 to 7.7 +/- 0.3), 770% of normal. In contrast to this, leg amputation had a negligible effect on T cell counts in Peyer's patches during all periods of observation.

CONCLUSIONS

We suggest that the major surgical stress (partial gastrectomy) may disturb the normal cell traffic selectively with increased gammadelta T cell homing in intestinal Peyer's patches and lymph nodes (GALT) and with the cell displacement from peripheral blood to lymphatic organs. The severity and localization of stress may be crucial.

Gamma/delta T cells from tolerized alpha/beta-TCR-deficient mice antigen specifically inhibit contact sensitivity in vivo and IFN-gamma production in vitro

Contact sensitivity (CS) responses to reactive hapten antigens (Ag), such as picryl chloride, are classical examples of T-cell-mediated immune responses in vivo. There is also abundant evidence that T cells exposed in vivo to high intravenous doses of Ag can downregulate CS (high-dose Ag tolerance). To clarify cell types that effect CS and mediate its downregulation, we have studied CS in mice congenitally deficient in alpha/beta T cells (alpha-/- mice). We show that alpha-/- mice cannot mount CS, implicating alpha/beta T cells as critical CS effector cells. However, after high-dose Ag tolerization, these alpha-/- mice can downregulate alpha/beta CS effector cells adoptively transferred to them. The active cells in tolerized alpha-/- mice are gamma/delta TCR+ cells which downregulate CS effector alpha/beta T cells Ag-specifically upon adoptive cell transfer. Moreover, gamma/delta cells can Ag-specifically downregulate IFN-gamma production by CS effector cells in vitro. These findings establish that gamma/delta T cells are not CS effector cells but downregulate CS, in agreement with recent reports that gamma/delta T cells downregulate IgE responses.

Gamma delta T cells from tolerized alpha beta T cell receptor (TCR)-deficient mice inhibit contact sensitivity-effector T cells in vivo, and their interferon-gamma production in vitro

Contact sensitivity (CS) responses to reactive hapten Ag, such as picryl chloride (PCl) or oxazolone (OX), are classical examples of T cell-mediated immune responses in vivo that are clearly subject to multifaceted regulation. There is abundant evidence that downregulation of CS may be mediated by T cells exposed to high doses of Ag. This is termed high dose Ag tolerance. To clarify the T cell types that effect CS responses and mediate their downregulation, we have undertaken studies of CS in mice congenitally deficient in specific subsets of lymphocytes. The first such studies, using alpha beta T cell-deficient (TCR alpha -/-) mice, are presented here. The results clearly show that TCR alpha -/- mice cannot mount CS, implicating alpha beta T cells as the critical CS-effector cells. However, TCR alpha -/- mice can, after high dose tolerance, downregulate alpha +/+ CS-effector T cells adoptively transferred into them. By mixing ex vivo and then adoptive cell transfers in vivo, the active downregulatory cells in tolerized alpha -/- mice are shown to include gamma delta TCR+ cells that also can downregulate interferon-gamma production by the targeted CS-effector cells in vitro. Downregulation by gamma delta cells showed specificity for hapten, but was not restricted by the MHC. Together, these findings establish that gamma delta T cells cannot fulfill CS-effector functions performed by alpha beta T cells, but may fulfill an Ag-specific downregulatory role that may be directly comparable to reports of Ag-specific downregulation of IgE antibody responses by gamma delta T cells. Comparisons are likewise considered with downregulation by gamma delta T cells occurring in immune responses to pathogens, tumors, and allografts, and in systemic autoimmunity.

Immune or normal gamma delta T cells that assist alpha beta T cells in elicitation of contact sensitivity preferentially use V gamma 5 and V delta 4 variable region gene segments

In the current study, we confirmed previous findings suggesting that gamma delta T cells were involved in the successful adoptive cell transfer of contact sensitivity (CS) by alpha beta CS-effector T cells. In this study, we used hamster anti-mouse gamma delta-TCR mAb treatment of CS-effector T cells, followed by enrichment and removal of the gamma delta T cells with goat anti-hamster Ig-linked magnetic beads, or by addition of hemolytic rabbit C. This removal of gamma delta T cells abrogated adoptive cell transfers of CS, despite the presence of alpha beta T cells that are known to mediate CS. FACS analysis documented enrichment of gamma delta T cells rising from 1 to 2% of the starting cells, to 60 to 95% of the magnetic bead adherent cells. Adoptive cell transfer of CS was reconstituted by adding back to the alpha beta cells, highly enriched gamma delta cells attached to anti-gamma delta-TCR magnetic beads. Not only were gamma delta-enriched T cells from sensitized mice able to assist immune CS-effector alpha beta T cells, but gamma delta T cells from normal nonimmune mice also had CS-assisting activity, and furthermore, neither were MHC-restricted in this function. Thus, CS-assisting gamma delta T cells were present endogenously in normal mice without prior immunization, and acted without Ag specificity and without MHC restriction, to assist CS-effector alpha beta T cells. Similar studies, with hamster mAbs specific for V gamma and V delta portions of gamma delta-TCR, demonstrated that the gamma delta T cells that assisted the CS-effector alpha beta T cells preferentially expressed V gamma 5 and V delta 4 in their TCR. PCR analysis on extracted mRNA showed that V gamma 5 and V delta 4 gene segments indeed were rearranged and expressed in the sensitized and normal lymph nodes; and one-and two-color FACS analysis of magnetic bead-fractionated cells suggested that V gamma 5 and V delta 4 were expressed on the same T cells. In summary, these results demonstrated that V gamma 5+, V delta 4+, gamma delta T cells were needed to assist alpha beta effector T cells in the adoptive cell transfer of CS.

Immune or normal gamma delta T cells that assist alpha beta T cells in elicitation of contact sensitivity preferentially use V gamma 5 and V delta 4 variable region gene segments

In the current study, we confirmed previous findings suggesting that gamma delta T cells were involved in the successful adoptive cell transfer of contact sensitivity (CS) by alpha beta CS-effector T cells. In this study, we used hamster anti-mouse gamma delta-TCR mAb treatment of CS-effector T cells, followed by enrichment and removal of the gamma delta T cells with goat anti-hamster Ig-linked magnetic beads, or by addition of hemolytic rabbit C. This removal of gamma delta T cells abrogated adoptive cell transfers of CS, despite the presence of alpha beta T cells that are known to mediate CS. FACS analysis documented enrichment of gamma delta T cells rising from 1 to 2% of the starting cells, to 60 to 95% of the magnetic bead adherent cells. Adoptive cell transfer of CS was reconstituted by adding back to the alpha beta cells, highly enriched gamma delta cells attached to anti-gamma delta-TCR magnetic beads. Not only were gamma delta-enriched T cells from sensitized mice able to assist immune CS-effector alpha beta T cells, but gamma delta T cells from normal nonimmune mice also had CS-assisting activity, and furthermore, neither were MHC-restricted in this function. Thus, CS-assisting gamma delta T cells were present endogenously in normal mice without prior immunization, and acted without Ag specificity and without MHC restriction, to assist CS-effector alpha beta T cells. Similar studies, with hamster mAbs specific for V gamma and V delta portions of gamma delta-TCR, demonstrated that the gamma delta T cells that assisted the CS-effector alpha beta T cells preferentially expressed V gamma 5 and V delta 4 in their TCR. PCR analysis on extracted mRNA showed that V gamma 5 and V delta 4 gene segments indeed were rearranged and expressed in the sensitized and normal lymph nodes; and one-and two-color FACS analysis of magnetic bead-fractionated cells suggested that V gamma 5 and V delta 4 were expressed on the same T cells. In summary, these results demonstrated that V gamma 5+, V delta 4+, gamma delta T cells were needed to assist alpha beta effector T cells in the adoptive cell transfer of CS.

[Pneumocystis pneumonia in light of personal observations]

During a period of 10 months, 87 children with Pneumocystis carinii pneumonia accompanied transient cellular immunity disorders and with normal humoral immunity were observed. It is suggested that change the invasiveness of the parasite has changed. The necessity of taking into consideration a pneumocystis etiology in diagnosis of respiratory tract diseases among children is pointed out.

[Curling's ulcer in a 9-month-old infant]

Burns are the most frequent severe trauma in childhood. Curling's ulcer is a complication of burn shock which occurs in the gastrointestinal tract in burned children. Prognosis in Curling's ulcer is always serious. A rare case of acute duodenal ulcer in a nine-month-old infant after deep burns of both lower extremities is described. It seems that it is necessary to take into consideration the possibility of Curling's ulcer in every case of deep and extensive burns in children.

Gamma delta T cells in normal spleen assist immunized alpha beta T cells in the adoptive cell transfer of contact sensitivity. Effect of Bordetella pertussis, cyclophosphamide, and antibodies to determinants on suppressor cells

Our prior studies showed that gamma delta T cells were required to assist alpha beta T cells in the successful adoptive cell transfer of contact sensitivity (CS) responsiveness. These TCR-gamma delta+ regulatory T cells in immune spleen and lymph node were CD3+, CD4-, CD8+, nonantigen-specific, and non-MHC-restricted. In the current work, experiments were conducted to determine the mechanisms of how the gamma delta T cells were required to assist the alpha beta T cells in CS. We found that similar regulatory gamma delta T cells were in the spleen of normal mice, but not in the spleen of nude nor SCID mice, suggesting that the regulatory gamma delta T cells were present before immunization and required the thymus for differentiation, and also required rearrangements of gamma delta V gene segments. Treatment of cell transfer recipient mice with Bordetella pertussis (Bp), or with a low dose of cyclophosphamide (50 mg/kg), restored the ability of alpha beta+ gamma delta- T cells to transfer CS. This and other results suggested that Bp caused the CS-assisting gamma delta T cells to leave the lymphoid organs (such as the spleen) and enter the circulation, and only then to be able to assist the TCR-alpha beta+ CS-effector T cells. This effect needed the simultaneous i.v. injection of the CS-effector alpha beta T cells and the CS-assisting gamma delta T cells. The results also suggested that treatment with cyclophosphamide inactivated suppressor T cells in the recipients that acted to inhibit the alpha beta T cell transfer of CS, and thus that the CS-assisting gamma delta T cells acted by protecting the CS-effector alpha beta T cells from this endogenous suppression. This suppression of CS transfers also was eliminated by treatment of recipients with two different mAbs to determinants on suppressor T cells. In conclusion, we have described regulatory TCR-gamma delta+ CS-assisting/protecting T cells that are non-antigen-specific, non-MHC-restricted, CD3+, CD8+ gamma delta T cells that may assist adoptive transferring CS-effector alpha beta T cells by making these effector T cells resistant to suppressor T cells in the normal recipients.