Food selection and effect of home preparation procedure for antibiotic food mixtures on homogeneity, stability, and dissolution

Amoxicillin, doxycycline, and clindamycin are among the commonly used antibiotics to treat bacterial infections. However, dosage forms of antibiotics for pediatric patients may not be as readily available as the formulations for adult patients. As such, it is anticipated that during a public health emergency, special instruction may need to be provided on home preparation and administration procedures to dose pediatric patients using available stockpiles of oral tablet and capsule dosage forms. Mixing crushed tablets or capsule contents with soft- or liquid- foods is one of the most common home preparation procedures. To gain knowledge for safe and effective use of prepared drug product instead of the intended intact dosage form, the impact of manipulation of the dosage form was studied. Capsule opening, capsule content assay and uniformity, dissolution, homogeneity, and stability studies of drug mixed with various liquid and soft foods were carried out using intact capsules of amoxicillin, doxycycline, and clindamycin. Higher recovery of capsule contents was achieved when using hands or knives to open capsules compared to using scissors. The capsules of all three antibiotic products contained the labeled amount of active pharmaceutical ingredients (API). The peanut butter-drug mixtures failed both United States Pharmacopeia (USP) assay and dissolution criteria because the peanut butter significantly affected the solubility of the drugs, and hence it was omitted from further study. All drug-food mixtures of the three antibiotic products and 15 selected foods exhibited fast dissolution (e.g., >80 % in 60 min) in the tested medium, except for the amoxicillin-chocolate pudding mixture. Three household containers (cups, plates, and bowls) and four mixing times (0.5 min, 1 min, 2 min, and 5 min) were found to be suitable for preparation of homogeneous mixtures of the antibiotics and foods. For practical purposes, 1 to 2 min mixing time is sufficient to produce homogeneous mixtures. The results of this study provided product quality data on the interactions between the antibiotics and the foods and can potentially support future development of home preparation instructions of antibiotics for pediatric patients or patients with swallowing difficulties.

CDC Guidelines for the Prevention and Treatment of Anthrax, 2023

This report updates previous CDC guidelines and recommendations on preferred prevention and treatment regimens regarding naturally occurring anthrax. Also provided are a wide range of alternative regimens to first-line antimicrobial drugs for use if patients have contraindications or intolerances or after a wide-area aerosol release of

Bacillus anthracis spores if resources become limited or a multidrug-resistant B. anthracis strain is used (Hendricks KA, Wright ME, Shadomy SV, et al.; Workgroup on Anthrax Clinical Guidelines. Centers for Disease Control and Prevention expert panel meetings on prevention and treatment of anthrax in adults. Emerg Infect Dis 2014;20:e130687; Meaney-Delman D, Rasmussen SA, Beigi RH, et al. Prophylaxis and treatment of anthrax in pregnant women. Obstet Gynecol 2013;122:885-900; Bradley JS, Peacock G, Krug SE, et al. Pediatric anthrax clinical management. Pediatrics 2014;133:e1411-36). Specifically, this report updates antimicrobial drug and antitoxin use for both postexposure prophylaxis (PEP) and treatment from these previous guidelines best practices and is based on systematic reviews of the literature regarding 1) in vitro antimicrobial drug activity against B. anthracis; 2) in vivo antimicrobial drug efficacy for PEP and treatment; 3) in vivo and human antitoxin efficacy for PEP, treatment, or both; and 4) human survival after antimicrobial drug PEP and treatment of localized anthrax, systemic anthrax, and anthrax meningitis.

Changes from previous CDC guidelines and recommendations include an expanded list of alternative antimicrobial drugs to use when first-line antimicrobial drugs are contraindicated or not tolerated or after a bioterrorism event when first-line antimicrobial drugs are depleted or ineffective against a genetically engineered resistant

B. anthracis strain. In addition, these updated guidelines include new recommendations regarding special considerations for the diagnosis and treatment of anthrax meningitis, including comorbid, social, and clinical predictors of anthrax meningitis. The previously published CDC guidelines and recommendations described potentially beneficial critical care measures and clinical assessment tools and procedures for persons with anthrax, which have not changed and are not addressed in this update. In addition, no changes were made to the Advisory Committee on Immunization Practices recommendations for use of anthrax vaccine (Bower WA, Schiffer J, Atmar RL, et al. Use of anthrax vaccine in the United States: recommendations of the Advisory Committee on Immunization Practices, 2019. MMWR Recomm Rep 2019;68[No. RR-4]:1-14). The updated guidelines in this report can be used by health care providers to prevent and treat anthrax and guide emergency preparedness officials and planners as they develop and update plans for a wide-area aerosol release of B. anthracis.

Safety of Antimicrobials for Postexposure Prophylaxis and Treatment of Anthrax: A Review

BACKGROUND

Bacillus anthracis, the causative agent for anthrax, poses a potential bioterrorism threat and is capable of causing mass morbidity and mortality. Antimicrobials are the mainstay of postexposure prophylaxis (PEP) and treatment of anthrax. We conducted this safety review of 24 select antimicrobials to identify any new or emerging serious or severe adverse events (AEs) to help inform their risk-benefit evaluation for anthrax.

METHODS

Twenty-four antimicrobials were included in this review. Tertiary data sources (e.g. Lactmed, Micromedex, REPROTOX) were reviewed for safety information and summarized to evaluate the known risks of these antimicrobials. PubMed was also searched for published safety information on serious or severe AEs with these antimicrobials; AEs that met inclusion criteria were abstracted and reviewed.

RESULTS

A total of 1316 articles were reviewed. No consistent observations or patterns were observed among the abstracted AEs for a given antimicrobial; therefore, the literature review did not reveal evidence of new or emerging AEs that would add to the risk-benefit profiles already known from tertiary data sources.

CONCLUSIONS

The reviewed antimicrobials have known and/or potential serious or severe risks that may influence selection when recommending an antimicrobial for PEP or treatment of anthrax. Given the high fatality rate of anthrax, the risk-benefit evaluation favors use of these antimicrobials for anthrax. The potential risks of antimicrobials should not preclude these reviewed antimicrobials from clinical consideration for anthrax but rather guide appropriate antimicrobial selection and prioritization across different patient populations with risk mitigation measures as warranted.

Safety of Antimicrobials During Pregnancy: A Systematic Review of Antimicrobials Considered for Treatment and Postexposure Prophylaxis of Plague

BACKGROUND

The safety profile of antimicrobials used during pregnancy is one important consideration in the decision on how to treat and provide postexposure prophylaxis (PEP) for plague during pregnancy.

METHODS

We searched 5 scientific literature databases for primary sources on the safety of 9 antimicrobials considered for plague during pregnancy (amikacin, gentamicin, plazomicin, streptomycin, tobramycin, chloramphenicol, doxycycline, sulfadiazine, and trimethoprim-sulfamethoxazole [TMP-SMX]) and abstracted data on maternal, pregnancy, and fetal/neonatal outcomes.

RESULTS

Of 13 052 articles identified, 66 studies (case-control, case series, cohort, and randomized studies) and 96 case reports were included, totaling 27 751 prenatal exposures to amikacin (n = 9), gentamicin (n = 345), plazomicin (n = 0), streptomycin (n = 285), tobramycin (n = 43), chloramphenicol (n = 246), doxycycline (n = 2351), sulfadiazine (n = 870), and TMP-SMX (n = 23 602). Hearing or vestibular deficits were reported in 18/121 (15%) children and 17/109 (16%) pregnant women following prenatal streptomycin exposure. First trimester chloramphenicol exposure was associated with an elevated risk of an undescended testis (odds ratio [OR] 5.9, 95% confidence interval [CI] 1.2-28.7). Doxycycline was associated with cardiovascular malformations (OR 2.4, 95% CI 1.2-4.7) in 1 study and spontaneous abortion (OR 2.8, 95% CI 1.9-4.1) in a separate study. First trimester exposure to TMP-SMX was associated with increased risk of neural tube defects (pooled OR 2.5, 95% CI 1.4-4.3), spontaneous abortion (OR 3.5, 95% CI 2.3-5.6), preterm birth (OR 1.5, 95% CI 1.1-2.1), and small for gestational age (OR 1.6, 95% CI 1.2-2.2). No other statistically significant associations were reported.

CONCLUSIONS

For most antimicrobials reviewed, adverse maternal/fetal/neonatal outcomes were not observed consistently. Prenatal exposure to streptomycin and TMP-SMX was associated with select birth defects in some studies. Based on limited data, chloramphenicol and doxycycline may be associated with adverse pregnancy or neonatal outcomes; however, more data are needed to confirm these associations. Antimicrobials should be used for treatment and PEP of plague during pregnancy; the choice of antimicrobials may be influenced by these data as well as information about the risks of plague during pregnancy.

COPD exacerbations . 3: Pathophysiology

Exacerbations of chronic obstructive pulmonary disease (COPD) are associated with increased morbidity and mortality. The effective management of COPD exacerbations awaits a better understanding of the underlying pathophysiological mechanisms that shape its clinical expression. The clinical presentation of exacerbations of COPD is highly variable and ranges from episodic symptomatic deterioration that is poorly responsive to usual treatment, to devastating life threatening events. This underscores the heterogeneous physiological mechanisms of this complex disease, as well as the variation in response to the provoking stimulus. The derangements in ventilatory mechanics, muscle function, and gas exchange that characterise severe COPD exacerbations with respiratory failure are now well understood. Critical expiratory flow limitation and the consequent dynamic lung hyperinflation appear to be the proximate deleterious events. Similar basic mechanisms probably explain the clinical manifestations of less severe exacerbations of COPD, but this needs further scientific validation. In this review we summarise what we have learned about the natural history of COPD exacerbations from clinical studies that have incorporated physiological measurements. We discuss the pathophysiology of clinically stable COPD and examine the impact of acutely increased expiratory flow limitation on the compromised respiratory system. Finally, we review the chain of physiological events that leads to acute ventilatory insufficiency in severe exacerbations.

Physiological changes during symptom recovery from moderate exacerbations of COPD

Acute exacerbations of chronic obstructive disease (AECOPD) are characterised by worsening dyspnoea that is variably prolonged. In this study, physiological changes during moderate AECOPD were examined and the factors associated with dyspnoea resolution over time were determined. In total, 20 patients experiencing an AECOPD were evaluated within 72 h of initial worsening of symptoms (day 0) with pulmonary function testing, metabolic testing and symptom assessment using the dyspnoea domain of the Chronic Respiratory Disease Questionnaire (CRQ). Treatment was optimised and testing was repeated after 7, 14, 30 and 60 days. At day 0, patients were very short of breath (CRQ-dyspnoea mean+/-SEM 2.4+/-0.3) and showed significant airflow obstruction (forced expiratory volume in one second (FEV1) 41+/-3% predicted) and lung hyperinflation (forced residual capacity (FRC) 164+/-7% pred). By day 60 CRQ-dyspnoea improved to 4.6+/-0.5 (some shortness of breath); FRC and residual volume decreased by 5 and 11%, respectively; inspiratory capacity (IC) and slow vital capacity increased by 18 and 17%, respectively; and FEV1 increased by 18% with no change in FEV1/FVC. Total lung capacity did not change during AECOPD, and thus, changes in IC reliably reflected changes in end-expiratory lung volume. In conclusion, moderate acute exacerbation of chronic obstructive pulmonary disease is characterised by worsening airflow obstruction and lung hyperinflation. Improvement of dyspnoea following acute exacerbations of chronic obstructive pulmonary disease was associated with reduction in lung hyperinflation and consequent increase in expiratory flow rates.

Intestinal mast cell progenitors require CD49dbeta7 (alpha4beta7 integrin) for tissue-specific homing

Mast cells (MCs) are centrally important in allergic inflammation of the airways, as well as in the intestinal immune response to helminth infection. A single lineage of bone marrow (BM)-derived progenitors emigrates from the circulation and matures into phenotypically distinct MCs in different tissues. Because the mechanisms of MC progenitor (MCp) homing to peripheral tissues have not been evaluated, we used limiting dilution analysis to measure the concentration of MCp in various tissues of mice deficient for candidate homing molecules. MCp were almost completely absent in the small intestine but were present in the lung, spleen, BM, and large intestine of beta7 integrin-deficient mice (on the C57BL/6 background), indicating that a beta7 integrin is critical for homing of these cells to the small intestine. MCp concentrations were not altered in the tissues of mice deficient in the alphaE integrin (CD103), the beta2 integrin (CD18), or the recombination activating gene (RAG)-2 gene either alone or in combination with the interleukin (IL)-receptor common gamma chain. Therefore, it is the alpha4beta7 integrin and not the alphaEbeta7 integrin that is critical, and lymphocytes and natural killer cells play no role in directing MCp migration under basal conditions. When MCp in BALB/c mice were eliminated with sublethal doses of gamma-radiation and then reconstituted with syngeneic BM, the administration of anti-alpha4beta7 integrin, anti-alpha4 integrin, anti-beta7 integrin, or anti-MAdCAM-1 monoclonal antibodies (mAbs) blocked the recovery of MCp in the small intestine. The blocking mAbs could be administered as late as 4 d after BM reconstitution with optimal inhibition, implying that the MCp must arise first in the BM, circulate in the vasculature, and then translocate into the intestine. Inasmuch as MCp are preserved in the lungs of beta7 integrin-deficient and anti-alpha4beta7 integrin-treated mice but not in the small intestine, alpha4beta7 integrin is critical for tissue specific extravasation for localization of MCp in the small intestine, but not the lungs.

Role of integrin alphaE(CD103)beta7 for tissue-specific epidermal localization of CD8+ T lymphocytes

Tissue-specific T cell localization is crucial for immune surveillance of normal tissues and the pathogenesis of inflammatory disorders. In psoriatic skin, CD8+ lymphocytes predominantly reside within the epidermis, whereas CD4+ T cells are most abundant within the dermis. Molecular mechanisms guiding this spatial compartmentalization are not completely understood, however. Here, we demonstrate that 55% (+/-9.7%, n = 14) of the epidermal T cells, predominantly of the CD8+ phenotype, expressed the integrin alphaE(CD103)beta7. In contrast, only 5% (+/-2.0%) of the dermal T cells were alphaE(CD103)beta7+. Integrin alphaE(CD103)beta7 was not detected in normal skin (n = 10), and less than 1% of peripheral blood lymphocytes derived from normal (n = 11) or psoriatic (n = 10) donors expressed alphaE(CD103). When cultured T lymphoblasts (n = 12 donors) were stimulated with transforming growth factor beta1, expression of integrin alphaE(CD103)beta7 was induced on 52.8% (+/-16.2%) of CD8+ cells, but only on 6.1% (+/-2.3%) of CD4+ cells, suggesting selective inducibility on CD8+ lymphocytes. Whereas similar overall expression of transforming-growth-factor-beta1-specific mRNA was detected in normal and psoriatic skin by real-time quantitative polymerase chain reaction, immunohistochemistry revealed focal overexpression of transforming growth factor beta1 underneath psoriatic, but not normal, epidermis. This heterogenous transforming growth factor beta1 expression may contribute to induction of alphaE(CD103) in vivo. Adhesion of transforming-growth-factor-beta1-stimulated CD8+, but not CD4+, T cells to cultured keratinocytes and psoriatic epidermis in frozen sections could be significantly inhibited by antibodies that blocked the alphaE(CD103)/E-cadherin interaction. Co-culture of lymphoblasts and keratinocytes resulted in marginal enhancement of alphaE(CD103)beta7 expression in some cases. Overall, integrin alphaE(CD103)beta7 appears to contribute to tissue-specific epidermal localization of CD8+ T lymphocytes.

Integrin alpha E(CD103)beta 7 mediates adhesion to intestinal microvascular endothelial cell lines via an E-cadherin-independent interaction

Integrins are important for T cell interactions with endothelial cells. Because the integrin alpha(E)beta(7) is expressed on some circulating gut-homing T cells and as T cell numbers are reduced in the intestinal lamina propria of alpha(E)-deficient mice, we evaluated whether alpha(E)beta(7) mediates binding to intestinal endothelial cells. We found that anti-alpha(E)beta(7) mAbs partially blocked the binding of cultured intraepithelial T cells to human intestinal microvascular endothelial cells (HIMEC). Furthermore, alpha(E)beta(7)-transfected K562 cells bound more efficiently than vector-transfected K562 cells to HIMEC. Finally, HIMEC bound directly to an alpha(E)beta(7)-Fc fusion protein. These interactions were partially blocked by anti-alpha(E)beta(7) mAbs, and endothelial cell binding to the alpha(E)beta(7)-Fc was dependent upon the metal ion-dependent adhesion site within the alpha(E) A domain. Of note, the HIMEC lacked expression of E-cadherin, the only known alpha(E)beta(7) counterreceptor as assessed by functional studies, flow cytometry, and RT-PCR. Thus, HIMEC/alpha(E)beta(7) binding was independent of E-cadherin. In addition, this interaction appeared to be tissue selective, as HIMEC bound to the alpha(E)beta(7)-Fc, whereas microvascular endothelial cells from the skin did not. Finally, there was evidence for an alpha(E)beta(7) ligand on intestinal endothelial cells in vivo, as alpha(E)beta(7) expression enhanced lymphocyte binding around vessels in the lamina propria in tissue sections. Thus, we have defined a novel interaction for alpha(E)beta(7) at a nonepithelial location. These studies suggest a role for alpha(E)beta(7) in interactions with the intestinal endothelium that may have implications for intestinal T cell homing or functional responses.

Cutaneous inflammatory disorder in integrin alphaE (CD103)-deficient mice

The integrin alpha(E)beta(7) is thought to play an important role in the localization of mucosal, but not of cutaneous T lymphocytes. Thus, it was surprising that 89% of adult alpha(E)(-/-) mice on the 129/Sv x BALB/c background developed inflammatory skin lesions without an apparent infectious etiology. Skin inflammation correlated with alpha(E) deficiency in mice with a mixed 129/Sv x BALB/c background, but not in mice further backcrossed to BALB/c and housed in a second animal facility. These studies suggested that alpha(E) deficiency, in combination with other genetic and/or environmental factors, is involved in lesion development. The lesions were infiltrated by CD4(+) T cells and neutrophils, and associated with increased expression of inflammatory cytokines. Furthermore, skin inflammation resulted from transfer of unfractionated alpha(E)(-/-) splenocytes into scid/scid mice, but not from transfer of wild-type splenocytes, suggesting that the lesions resulted from immune dysregulation. We also studied the role of alpha(E)beta(7) in a murine model of hyperproliferative inflammatory skin disorders that is induced by transfer of minor histocompatibility-mismatched CD4(+)/CD45RB(high) T cells into scid/scid mice under specific environmental conditions. Under housing conditions that were permissive for lesion development, transfer of alpha(E)-deficient CD4(+)/CD45RB(high) T cells significantly exacerbated the cutaneous lesions as compared with lesions observed in mice reconstituted with wild-type donor cells. These experiments suggested that alpha(E)-expressing cells play an important role during the course of cutaneous inflammation. In addition, they suggest that alpha(E)beta(7) deficiency, in combination with other genetic or environmental factors, is a risk factor for inflammatory skin disease.

In vivo roles of integrins during leukocyte development and traffic: insights from the analysis of mice chimeric for alpha 5, alpha v, and alpha 4 integrins

Mice chimeric for integrins alpha(5), alpha(V), or alpha(4) were used to dissect the in vivo roles of these adhesion receptors during leukocyte development and traffic. No major defects were observed in the development of lymphocytes, monocytes, or granulocytes or in the traffic of lymphocytes to different lymphoid organs in the absence of alpha(5) or alpha(V) integrins. However, in agreement with previous reports, the absence of alpha(4) integrins produced major defects in development of lymphoid and myeloid lineages and a specific defect in homing of lymphocytes to Peyer's patches. In contrast, the alpha(4) integrin subunit is not essential for localization of T lymphocytes into intraepithelial and lamina propria compartments in the gut, whereas one of the partners of alpha(4), the beta(7) chain, has been shown to be essential. However, alpha(4)-deficient T lymphocytes cannot migrate properly during the inflammatory response induced by thioglycolate injection into the peritoneum. Finally, in vitro proliferation and activation of lymphocytes deficient for alpha(5), alpha(V), or alpha(4) integrins upon stimulation with different stimuli were similar to those seen in controls. These results show that integrins play distinct roles during in vivo leukocyte development and traffic.

T-lymphocyte-epithelial-cell interactions: integrin alpha(E)(CD103)beta(7), LEEP-CAM and chemokines

The epithelia are the avascular layers of cells that cover the environment-exposed surfaces of the body. It appears that T cells localize to selected sites in or adjacent to epithelia via the selective expression of adhesion molecules and chemokine receptors on T cells. These bind to counter-receptors and to chemokines expressed by epithelial cells. Recently, there has been an advance in our understanding of the interaction of the alpha(Ebeta7) integrin with its epithelial cell ligand, E-cadherin. In addition, a new adhesion molecule has been identified on non-intestinal epithelial cells, termed lymphocyte-endothelial-epithelial-cell adhesion molecule (LEEP-CAM). Finally, there have been advances in our understanding of the role of skin- or gut-epithelia-derived chemokines in regulating activated T cell homing to these sites.

Postoperative analgesia after peripheral nerve block for podiatric surgery: clinical efficacy and chemical stability of lidocaine alone versus lidocaine plus ketorolac

BACKGROUND AND OBJECTIVES

The purpose of this study was to determine whether the addition of ketorolac tromethamine to local anesthesia for ankle block alters the quality or duration of analgesia after podiatric surgery. The second aim was to determine the chemical stability of ketorolac tromethamine when added to local anesthetic solutions.

METHODS

The study design was double-blinded, placebo-controlled, and randomized. Seventy-nine American Society of Anesthesiologists (ASA) class I or II patients scheduled for bunionectomy or hammer toe repair, or both were randomized to 1 of 4 groups. Group L received plain 1.73% lidocaine for their ankle block. Group K received 1.73% lidocaine with ketorolac (4 mg/mL) added to the local solution. Group Kiv received 1.73% plain lidocaine for ankle block and 20 mg of ketorolac intravenously. Group E received 1.73% lidocaine with .67% ethanol added. The final concentration of lidocaine for all groups was 1.73%. The block performed in each patient was a 5-point ankle block. Beginning at 1 hour after the completion of the block and every 30 minutes thereafter, visual analogue scale (VAS) and verbal pain scores were recorded. The time from performance of the block to the initial pain and time to the first oral pain medication intake were also recorded. The time and amount of postoperative oral analgesics in the first 9 hours after the block were recorded. Adverse events were also recorded for each group.

RESULTS

There were significantly lower overall VAS and verbal pain scores for group K compared with groups E and L and group Kiv compared with group E. Group K also had a significantly longer time to the first reported pain and first oral pain medications than groups E and L, but not with Group Kiv. The same group had significantly fewer average doses of pain medications postoperatively than Groups E and L. Group E had significantly shorter times to first report of pain and first pain medications and higher mean dose of postoperative oral analgesics than group K and Group Kiv. There were no untoward side effects reported from any group. Chemical analysis by gas chromatography (GC) and capillary electrophoresis (CE) showed no significant change in composition of the solutions when ketorolac was mixed with lidocaine and/or bupivacaine and stored at 37 degrees C for 1 week.

CONCLUSIONS

The addition of ketorolac to lidocaine for ankle block contributed to longer duration and better quality analgesia after foot surgery compared with plain 1.73% lidocaine or 1.73% lidocaine plus intravenous ketorolac. The ethanol vehicle is unlikely responsible for the analgesic effects of ketorolac. Ketorolac retains its chemical stability when placed in local solutions of lidocaine or bupivacaine.

Constitutive expression of stromal derived factor-1 by mucosal epithelia and its role in HIV transmission and propagation

HIV particles that use the chemokine receptor CXCR4 as a coreceptor for entry into cells (X4-HIV) inefficiently transmit infection across mucosal surfaces [1], despite their presence in seminal fluid and mucosal secretions from infected individuals [2] [3] [4]. In addition, although intestinal lymphocytes are susceptible to infection with either X4-HIV particles or particles that use the chemokine receptor CCR5 for viral entry (R5-HIV) during ex vivo culture [5], only systemic inoculation of R5-chimeric simian-HIV (S-HIV) results in a rapid loss of CD4(+) intestinal lymphocytes in macaques [6]. The mechanisms underlying the inefficient capacity of X4-HIV to transmit infection across mucosal surfaces and to infect intestinal lymphocytes in vivo have remained elusive. The CCR5 ligands RANTES, MIP-1alpha and MIP-1beta suppress infection by R5-HIV-1 particles via induction of CCR5 internalization, and individuals whose peripheral blood lymphocytes produce high levels of these chemokines are relatively resistant to infection [7] [8] [9]. Here, we show that the CXCR4 ligand stromal derived factor-1 (SDF-1) is constitutively expressed by mucosal epithelial cells at sites of HIV transmission and propagation. Furthermore, CXCR4 is selectively downmodulated on intestinal lymphocytes within the setting of prominent SDF-1 expression. We postulate that mucosally derived SDF-1 continuously downmodulates CXCR4 on resident HIV target cells, thereby reducing the transmission and propagation of X4-HIV at mucosal sites. Moreover, such a mechanism could contribute to the delayed emergence of X4 isolates, which predominantly occurs during the later stages of the HIV infection.

Human intestinal lamina propria and intraepithelial lymphocytes express receptors specific for chemokines induced by inflammation

To determine which chemokine receptors might be involved in T lymphocyte localization to the intestinal mucosa, we examined receptor expression on human intestinal lamina propria lymphocytes (LPL), intraepithelial lymphocytes (IEL) and CD45RO+beta7hi gut homing peripheral blood lymphocytes (PBL). Virtually all LPL and IEL expressed CXCR3 and CCR5, receptors that have been associated with Th1(Tc1)/Th0 lymphocytes, while CCR3 and CCR4, receptors associated with Th2 (Tc2)lymphocytes, CCR7, CXCR1 and CXCR2 were not expressed. CXCR3 and CCR5 receptors were functional, as LPL and IEL migrated to their respective ligands I-TAC and RANTES. In addition, most alphaEbeta7- LPL and IEL expressed high levels of CCR2. While the majority of CD45RO(-)beta7hi PBL also expressed CXCR3 and CCR5, a proportion of these cells were CXCR3- and/or CCR5- and some expressed CCR4 and/or CCR7, indicating that lymphocytes recruited to the intestinal mucosa represent a subset of these cells. In summary, our results show that LPL and IEL within the normal intestine express a specific and similar array of chemokine receptors whose ligands are constitutively expressed in the intestinal mucosa and whose expression is up-regulated during intestinal inflammation. These results support the view that CXCR3, CCR5 and CCR2 may play an important role in lymphocyte localization within the intestinal mucosa.

Human intestinal lamina propria and intraepithelial lymphocytes express receptors specific for chemokines induced by inflammation

To determine which chemokine receptors might be involved in T lymphocyte localization to the intestinal mucosa, we examined receptor expression on human intestinal lamina propria lymphocytes (LPL), intraepithelial lymphocytes (IEL) and CD45RO+beta7hi gut homing peripheral blood lymphocytes (PBL). Virtually all LPL and IEL expressed CXCR3 and CCR5, receptors that have been associated with Th1(Tc1)/Th0 lymphocytes, while CCR3 and CCR4, receptors associated with Th2 (Tc2)lymphocytes, CCR7, CXCR1 and CXCR2 were not expressed. CXCR3 and CCR5 receptors were functional, as LPL and IEL migrated to their respective ligands I-TAC and RANTES. In addition, most alphaEbeta7- LPL and IEL expressed high levels of CCR2. While the majority of CD45RO(-)beta7hi PBL also expressed CXCR3 and CCR5, a proportion of these cells were CXCR3- and/or CCR5- and some expressed CCR4 and/or CCR7, indicating that lymphocytes recruited to the intestinal mucosa represent a subset of these cells. In summary, our results show that LPL and IEL within the normal intestine express a specific and similar array of chemokine receptors whose ligands are constitutively expressed in the intestinal mucosa and whose expression is up-regulated during intestinal inflammation. These results support the view that CXCR3, CCR5 and CCR2 may play an important role in lymphocyte localization within the intestinal mucosa.

Lymphocyte adhesion to epithelia and endothelia mediated by the lymphocyte endothelial-epithelial cell adhesion molecule glycoprotein

Upon encountering the relevant vascular bed, lymphocytes attach to endothelial adhesion molecules, transmigrate out of circulation, and localize within tissues. Lymphocytes may then be retained at microanatomic sites, as in tissues, or they may continue to migrate to the lymphatics and recirculate in the blood. Lymphocytes also interact transiently, but with high avidity, with target cells or APC that are infected with microbes or have taken up exogenous foreign Ags. This array of adhesive capabilities is mediated by the selective expression of lymphocyte adhesion molecules. Here, we developed the 6F10 mAb, which recognizes a cell surface glycoprotein designated lymphocyte endothelial-epithelial cell adhesion molecule (LEEP-CAM), that is distinct in biochemical characteristics and distribution of expression from other molecules known to play a role in lymphocyte adhesion. LEEP-CAM is expressed on particular epithelia, including the suprabasal region of the epidermis, the basal layer of bronchial and breast epithelia, and throughout the tonsillar and vaginal epithelia. Yet, it is absent from intestinal and renal epithelia. Interestingly, it is expressed also on vascular endothelium, especially high endothelial venules (HEV) in lymphoid organs, such as tonsil and appendix. The anti-LEEP-CAM mAb specifically blocked T and B lymphocyte adhesion to monolayers of epithelial cells and to vascular endothelial cells in static cell-to-cell binding assays by approximately 40-60% when compared with control mAbs. These data suggest a role for this newly identified molecule in lymphocyte binding to endothelium, as well as adhesive interactions within selected epithelia.

Mucosal T lymphocyte numbers are selectively reduced in integrin alpha E (CD103)-deficient mice

The mucosal lymphocyte integrin alpha E(CD103)beta 7 is thought to be important for intraepithelial lymphocyte (IEL) localization or function. We cloned the murine integrin gene encoding alpha E, localized it to chromosome 11, and generated integrin alpha E-deficient mice. In alpha E-/- mice, intestinal and vaginal IEL numbers were reduced, consistent with the known binding of alpha E beta 7 to E-cadherin expressed on epithelial cells. However, it was surprising that lamina propria T lymphocyte numbers were diminished, as E-cadherin is not expressed in the lamina propria. In contrast, peribronchial, intrapulmonary, Peyer's patch, and splenic T lymphocyte numbers were not reduced in alpha E-deficient mice. Thus, alpha E beta 7 was important for generating or maintaining the gut and vaginal T lymphocytes located diffusely within the epithelium or lamina propria but not for generating the gut-associated organized lymphoid tissues. Finally, the impact of alpha E deficiency upon intestinal IEL numbers was greater at 3-4 wk of life than in younger animals, and affected the TCR alpha beta+ CD8+ T cells more than the gamma delta T cells or the TCR alpha beta+ CD4+CD8- population. These findings suggest that alpha E beta 7 is involved in the expansion/recruitment of TCR alpha beta+ CD8+ IEL following microbial colonization. Integrin alpha E-deficient mice will provide an important tool for studying the role of alpha E beta 7 and of alpha E beta 7-expressing mucosal T lymphocytes in vivo.

The role of beta7 integrins in CD8 T cell trafficking during an antiviral immune response

The requirement of beta7 integrins for lymphocyte migration was examined during an ongoing immune response in vivo. Transgenic mice (OT-I) expressing an ovalbumin-specific major histocompatibility complex class I-restricted T cell receptor for antigen were rendered deficient in expression of all beta7 integrins or only the alphaEbeta7 integrin. To quantitate the relative use of beta7 integrins in migration in vivo, equal numbers of OT-I and OT-I-beta7(-/-) or OT-I-alphaE-/- lymph node (LN) cells were adoptively transferred to normal mice. Although OT-I-beta7(-/-) LN cells migrated to mesenteric LN and peripheral LN as well as wild-type cells, beta7 integrins were required for naive CD8 T cell and B cell migration to Peyer's patch. After infection with a recombinant virus (vesicular stomatitis virus) encoding ovalbumin, beta7 integrins became critical for migration of activated CD8 T cells to the mesenteric LN and Peyer's patch. Naive CD8 T cells did not enter the lamina propria or the intestinal epithelium, and the majority of migration of activated CD8 T cells to the small and large intestinal mucosa, including the epithelium, was beta7 integrin-mediated. The alphaEbeta7 integrin appeared to play no role in migration during a primary CD8 T cell immune response in vivo. Furthermore, despite dramatic upregulation of alphaEbeta7 by CD8 T cells after entry into the epithelium, long-term retention of intestinal intraepithelial lymphocytes was also alphaEbeta7 independent.

Direct and regulated interaction of integrin alphaEbeta7 with E-cadherin

The cadherins are a family of homophilic adhesion molecules that play a vital role in the formation of cellular junctions and in tissue morphogenesis. Members of the integrin family are also involved in cell to cell adhesion, but bind heterophilically to immunoglobulin superfamily molecules such as intracellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, or mucosal addressin cell adhesion molecule (MadCAM)-1. Recently, an interaction between epithelial (E-) cadherin and the mucosal lymphocyte integrin, alphaEbeta7, has been proposed. Here, we demonstrate that a human E-cadherin-Fc fusion protein binds directly to soluble recombinant alphaEbeta7, and to alphaEbeta7 solubilized from intraepithelial T lymphocytes. Furthermore, intraepithelial lymphocytes or transfected JY' cells expressing the alphaEbeta7 integrin adhere strongly to purified E-cadherin-Fc coated on plastic, and the adhesion can be inhibited by antibodies to alphaEbeta7 or E-cadherin. The binding of alphaEbeta7 integrin to cadherins is selective since cell adhesion to P-cadherin-Fc through alphaEbeta7 requires >100-fold more fusion protein than to E-cadherin-Fc. Although the structure of the alphaE-chain is unique among integrins, the avidity of alphaEbeta7 for E-cadherin can be regulated by divalent cations or phorbol myristate acetate. Cross-linking of the T cell receptor complex on intraepithelial lymphocytes increases the avidity of alphaEbeta7 for E-cadherin, and may provide a mechanism for the adherence and activation of lymphocytes within the epithelium in the presence of specific foreign antigen. Thus, despite its dissimilarity to known integrin ligands, the specific molecular interaction demonstrated here indicates that E-cadherin is a direct counter receptor for the alphaEbeta7 integrin.

Powered functional endoscopic sinus surgery

The use of powered instrumentation in functional endoscopic sinus surgery has been a revolutionary development in the surgical treatment of chronic sinusitis. Several studies have demonstrated the safety, efficacy, and ease of use of this new technique. To provide support and coordinate the surgical process in powered functional endoscopic sinus surgery procedures, perioperative nurses must have an appreciation for its specific equipment handling and for appropriate patient care. This article describes a specific protocol that perioperative nurses can use to facilitate efficient and safe surgical environments for patients who undergo powered endoscopic sinus surgery procedures.

Internal validity of the disruptive behavior disorder symptoms: implications from parent ratings for a dimensional approach to symptom validity

A dimensional approach was used to evaluate the internal validity of the DSM-III-R ADHD-inattention, ADHD-hyperactivity/impulsivity, oppositional defiant disorder (ODD), and conduct disorder (CD) symptoms (i.e., whether a symptom has a stronger correlation with its own dimension that the other three). Parents rated 4,019 children between the ages of 2 and 19 on these symptoms. The results showed that 5 of the 6 inattention symptoms, 3 of the 4 hyperactivity symptoms, 1 of the 4 impulsivity symptoms, 6 of the 9 oppositional defiant disorder symptoms, and 8 of the 11 CD symptoms had significant internal validity. Confirmatory factor analysis (CFA) found support for inattention, hyperactivity/impulsivity, oppositional defiant, and conduct disorder dimensions. Multiple-group CFA also found support for factor pattern and loading invariance across gender. The implications of these results as well as the merits of the dimensional approach to symptom validity are discussed in the context of the DSM-IV changes in ADHD, ODD, and CD.

Murine psoriasis-like disorder induced by naive CD4+ T cells

Psoriasis is a complex disorder involving alterations of many cell types. Although evidence suggests a T-cell pathogenesis for psoriasis, a primary role of T cells has not been directly demonstrated. Here, we show that reconstitution of scid/scid mice with minor histocompatibility mismatched naive CD4+ T lymphocytes resulted in skin alterations that strikingly resembled human psoriasis clinically, histopathologically and in cytokine expression. This skin disorder was diminished when memory T cells were coinjected. Thus, a subset of dysregulated CD4+ T cells can cause tissue alterations seen in psoriasis without the presence of CD8+ cells or a primary epithelial abnormality.

p126 (CDw101), a costimulatory molecule preferentially expressed on mucosal T lymphocytes

Intestinal mucosal lymphocytes are defined by their anatomic location within the epithelium (intraepithelial lymphocytes), the interstitium between the epithelial basement membrane and the underlying muscularis mucosa (lamina propria lymphocytes), or in organized lymphoid tissues (Peyer's patches). Although intestinal intraepithelial lymphocytes have a distinct localization, their function has not been determined. To define cell surface proteins that are involved in intestinal intraepithelial lymphocyte localization or function, cultured human mucosal lymphocytes were used as immunogens to develop mAbs that react predominantly with this cell population in an immunohistochemical screening assay. Three mAbs were selected that subsequently were found by biochemical analysis to identify a 200-kDa homodimeric polypeptide on 88 to 98% of CD3+ mucosal lymphocytes but only 18 +/- 13% of PBLs. Expression on granulocytes and monocytes was also observed. This polypeptide has been termed p126 based on its SDS-PAGE-determined M(r) under reducing conditions. Cleveland digest maps demonstrated similarity between the p126 and CDw101 polypeptides. Determined amino acid sequence analysis of the purified p126 polypeptide revealed that it is the protein product of the recently identified V7 gene, which has structural similarities to members of the Ig gene superfamily. Two of the anti-p126 mAbs were costimulatory with suboptimal concentrations of anti-CD3 mAb inducing proliferation of cultured intestinal intraepithelial lymphocytes. Thus, we conclude that p126 is CDw101 encoded by a gene that predicts a seven-Ig domain chain-like structure. It has restricted expression predominantly on mucosal T lymphocytes and appears to have a costimulatory function of special relevance for CD28- T cells and for mucosal lymphocytes.

p126 (CDw101), a costimulatory molecule preferentially expressed on mucosal T lymphocytes

Intestinal mucosal lymphocytes are defined by their anatomic location within the epithelium (intraepithelial lymphocytes), the interstitium between the epithelial basement membrane and the underlying muscularis mucosa (lamina propria lymphocytes), or in organized lymphoid tissues (Peyer's patches). Although intestinal intraepithelial lymphocytes have a distinct localization, their function has not been determined. To define cell surface proteins that are involved in intestinal intraepithelial lymphocyte localization or function, cultured human mucosal lymphocytes were used as immunogens to develop mAbs that react predominantly with this cell population in an immunohistochemical screening assay. Three mAbs were selected that subsequently were found by biochemical analysis to identify a 200-kDa homodimeric polypeptide on 88 to 98% of CD3+ mucosal lymphocytes but only 18 +/- 13% of PBLs. Expression on granulocytes and monocytes was also observed. This polypeptide has been termed p126 based on its SDS-PAGE-determined M(r) under reducing conditions. Cleveland digest maps demonstrated similarity between the p126 and CDw101 polypeptides. Determined amino acid sequence analysis of the purified p126 polypeptide revealed that it is the protein product of the recently identified V7 gene, which has structural similarities to members of the Ig gene superfamily. Two of the anti-p126 mAbs were costimulatory with suboptimal concentrations of anti-CD3 mAb inducing proliferation of cultured intestinal intraepithelial lymphocytes. Thus, we conclude that p126 is CDw101 encoded by a gene that predicts a seven-Ig domain chain-like structure. It has restricted expression predominantly on mucosal T lymphocytes and appears to have a costimulatory function of special relevance for CD28- T cells and for mucosal lymphocytes.

Adhesion between epithelial cells and T lymphocytes mediated by E-cadherin and the alpha E beta 7 integrin

In contrast to sessile cell types, lymphocytes migrate through the vasculature to become diffusely distributed in tissues or organized in lymphoid structures. A complex array of adhesion molecules including selectins, integrins and their counter-receptors mediate lymphocyte homing and migration into tissues and may be constitutively expressed or induced. However, the molecules that mediate the tissue-specific retention of lymphocytes within the parenchyma have not been identified. Along the epithelium at the basolateral surface of enterocytes, intestinal intraepithelial lymphocytes are found. These T cells of the mucosal immune system serve as a model for the tissue-specific compartmentalization of lymphocytes. We investigated whether the localization of these intestinal intraepithelial lymphocytes could be mediated by specific interactions between adhesion molecules expressed selectively on this subpopulation of T cells and tissue-restricted adhesion molecules on epithelial cells. Here we show that heterotypic adhesive interactions between epithelial cells and intraepithelial lymphocytes in vitro are mediated by E-cadherin and the alpha E beta 7 integrin.

TCR usage and functional capabilities of human gamma delta T cells at birth

Little is known about the gamma delta T cells in human neonatal umbilical cord blood. To compare neonatal cord blood and adult blood gamma delta T cells, we studied the V gamma and V delta gene segment usage in these populations by flow cytometry, and we derived cord blood gamma delta T cell clones to determine their functional capabilities. Unlike adult blood gamma delta T cells that predominantly express V gamma 2V delta 2 TCRs, neonatal cord blood gamma delta T cells expressed diverse V gamma and V delta gene segments paired in a variety of combinations rarely observed in adults. gamma delta T cell clones derived from neonatal cord blood similarly expressed a diverse array of TCRs. These cord blood-derived gamma delta T cell clones had weak cytolytic activity when assayed for K562 tumor cell killing, lectin-mediated cytolysis, and redirected cytolysis. They also expressed lower levels of the CD2, LFA-1, and CD45RO cell surface receptors as compared with strongly cytolytic adult gamma delta T cell clones. These properties of the cord blood-derived gamma delta T cell clones, weak cytotoxic activity and low adhesion molecule expression, were similar to the properties of the CD4+ subset of adult gamma delta T cells. Thus, neonatal gamma delta T cells are functionally different from the majority of adult gamma delta T cells and display a distinct TCR repertoire and accessory molecule profile.

TCR usage and functional capabilities of human gamma delta T cells at birth

Little is known about the gamma delta T cells in human neonatal umbilical cord blood. To compare neonatal cord blood and adult blood gamma delta T cells, we studied the V gamma and V delta gene segment usage in these populations by flow cytometry, and we derived cord blood gamma delta T cell clones to determine their functional capabilities. Unlike adult blood gamma delta T cells that predominantly express V gamma 2V delta 2 TCRs, neonatal cord blood gamma delta T cells expressed diverse V gamma and V delta gene segments paired in a variety of combinations rarely observed in adults. gamma delta T cell clones derived from neonatal cord blood similarly expressed a diverse array of TCRs. These cord blood-derived gamma delta T cell clones had weak cytolytic activity when assayed for K562 tumor cell killing, lectin-mediated cytolysis, and redirected cytolysis. They also expressed lower levels of the CD2, LFA-1, and CD45RO cell surface receptors as compared with strongly cytolytic adult gamma delta T cell clones. These properties of the cord blood-derived gamma delta T cell clones, weak cytotoxic activity and low adhesion molecule expression, were similar to the properties of the CD4+ subset of adult gamma delta T cells. Thus, neonatal gamma delta T cells are functionally different from the majority of adult gamma delta T cells and display a distinct TCR repertoire and accessory molecule profile.

Distinct structural and functional epitopes of the alpha E beta 7 integrin

Intestinal intraepithelial lymphocytes (iIEL) are predominantly CD3+, CD8+ T lymphocytes located above or adjacent to the mucosal basement membrane. Although they are positioned to interact with intercellular luminal antigen or with enterocytes, the function of iIEL remains unknown. Most (> 85%) of the iIEL express the alpha E beta 7 integrin which appears to be involved in the adhesion of lymphocytes to epithelial cells. We report the characterization of three monoclonal antibodies (mAb) termed alpha E7-1, alpha E7-2, and alpha E7-3, that react with the alpha E beta 7 integrin recognized by the previously described mAb HML-1 as demonstrated by identical sodium dodecyl sulfate-polyacrylamide gel electrophoresis mobility and charge. Flow cytometric analysis of antibody cross-blocking indicated that these mAb recognize distinct epitopes of alpha E beta 7. While all of the mAb were capable of blocking the adhesion of cultured iIEL to a breast epithelial cell line, only HML-1 and alpha E7-1 (which recognize an identical or closely related epitope) were co-stimulatory with suboptimal concentrations of anti-CD3 mAb in inducing proliferation of cultured iIEL. Thus, these mAb appear to recognize functionally distinct epitopes of alpha E beta 7 and will be useful to study relationships between the structure and function of this integrin.

Murine M290 integrin expression modulated by mast cell activation

Intraepithelial T lymphocytes possess a (TGF beta)-inducible integrin complex that consists of the beta 7 integrin chain in association with a novel alpha chain, murine alpha M290. Using antibodies directed against the murine alpha M290 chain, IL-3-dependent murine bone marrow-derived mast cells demonstrated positive staining after induction with TGF beta. Sequence information from the human intraepithelial T lymphocyte-alpha E gene sequence was used to clone the murine homolog from a TGF beta-induced T cell library. The murine alpha E homolog gene encodes a protein recognized by antibodies to alpha M290. Expression of this gene by bone marrow-derived mast cells was found to be induced by TGF beta or IgE-mediated cross-linking of Fc epsilon R1. Furthermore, exposure of murine TK-1 cells to supernatants from activated mast cells induces the expression of the alpha M290 gene, indicating that a mast cell mediator(s) can act in a paracrine manner to induce expression of this integrin complex by other cells.

Evidence for a structural difference in the CD7 polypeptide on human thymocytes and intraepithelial lymphocytes defined by a new monoclonal antibody, 3D9

Intestinal intraepithelial lymphocytes (IEL) represent a distinct subpopulation of lymphocytes located on or above the basement membrane and adjacent to the basolateral membrane of enterocytes. Thus IEL are strategically positioned to mediate a response to the uptake of foreign antigens or to the alteration of enterocytes by injury or infection. Because of their unique location, we hypothesized that IEL might selectively express specialized cell surface proteins important in their site-specific localization or function. To identify such proteins, we immunized mice with purified human IEL and identified one monoclonal antibody, 3D9, which was found to react with a majority of IEL but with very few lamina propria lymphocytes (LPL) and weakly with most peripheral blood lymphocytes (PBL). Evaluation of this antibody with two-dimensional gels demonstrated that it reacts with CD7, previously known as an early thymocyte differentiation antigen. Interestingly, unlike all other anti-CD7 monoclonal antibodies, 3D9 identified only occasional thymocytes by immunohistochemistry suggesting that CD7 is structurally different on IEL and thymocytes. However, the CD7 polypeptide immunoprecipitated from IEL and thymocytes appeared identical in SDS-PAGE mobility and in charge by two-dimensional gels, despite being recognized differently by monoclonal antibodies. These studies emphasize the expression of CD7 by IEL T cells and reveal the existence of an undefined structural difference between CD7 molecules on IEL compared to thymocytes.

Molecular cloning of the human mucosal lymphocyte integrin alpha E subunit. Unusual structure and restricted RNA distribution

The human mucosal lymphocyte-1 (HML-1) antigen is expressed on a subclass of T-lymphocytes known as intra-epithelial lymphocytes which are located between mucosal epithelial cells. The HML-1 complex is known to mediate adhesion of intra-epithelial T-lymphocytes to epithelial cell monolayers in vitro. We and others have shown that the HML-1 antigen is an integrin composed of the beta 7 subunit in association with a novel alpha subunit, alpha E. Here we report the cloning of the alpha E cDNA and its primary amino acid sequence. alpha E contained an inserted or I domain and was more homologous to the other I domain containing integrins than to the cleaved group of integrin alpha subunits. However, alpha E contained a unique extra domain of 55 amino acids located just NH2-terminal to the I domain without counterpart in other integrins. This extra domain contained a stretch of 18 consecutive charged residues and included a proteolytic cleavage site. Thus alpha E is the only I domain containing integrin alpha subunit that is also cleaved, and the cleavage site is distinct from that of members of the cleaved group of integrin alpha subunits. These structural features mark alpha E as an unusual member of the integrin family. High levels of alpha E and beta 7 mRNA were restricted to mucosal lymphocytes supporting the hypothesis that alpha E beta 7 plays a role in the localization or site-specific functions of intra-epithelial T-lymphocytes.

Integrin alpha E beta 7 mediates adhesion of T lymphocytes to epithelial cells

Intestinal intraepithelial lymphocytes (iIEL) are a distinct subpopulation of T lymphocytes diffusely distributed in the epithelium. Because > 95% of these iIEL express the integrin alpha E beta 7, we reasoned that this integrin might mediate the localization of iIEL to the epithelium. We report that cultured iIEL bound to mucosal epithelial cells derived from either breast or intestine. This binding was dependent on the presence of divalent cations, and was blocked by mAb specific for two integrins, alpha E beta 7 and alpha L beta 2. After TGF-beta 1 treatment, cultured iIEL cell lines expressed alpha E beta 7 at levels similar to those found on iIEL in vivo. Under these conditions this integrin appeared to predominate in mediating the adhesion of iIEL to epithelial cells. Although alpha L beta 2 blocked the adhesion of iIEL to both endothelial and epithelial cells, alpha E beta 7 blocked binding only to epithelial cells suggesting that the ligand for alpha E beta 7 is not expressed on IL-1 beta-treated cultured endothelial cells. iIEL did not readily bind to the apical surface of confluent polarized epithelial cell monolayers. However, iIEL did bind to these cells when tight junctions were disrupted, a treatment that allows redistribution of proteins compartmentalized to the basolateral surface. This binding was also blocked by mAb to alpha E beta 7. In addition, in vitro coculture of iIEL with polarized epithelial cells resulted in basolateral localization of the iIEL. Thus, it is likely that expression of the alpha E beta 7 ligand is restricted to the basolateral membrane of polarized epithelial cells. Because alpha E beta 7 appears to be a predominant integrin on freshly isolated iIEL, we hypothesized that alpha E beta 7-mediated adhesion may be particularly important in cell-to-cell interactions between T cells and epithelial cells in vivo.

Integrin alpha E beta 7 mediates adhesion of T lymphocytes to epithelial cells

Intestinal intraepithelial lymphocytes (iIEL) are a distinct subpopulation of T lymphocytes diffusely distributed in the epithelium. Because > 95% of these iIEL express the integrin alpha E beta 7, we reasoned that this integrin might mediate the localization of iIEL to the epithelium. We report that cultured iIEL bound to mucosal epithelial cells derived from either breast or intestine. This binding was dependent on the presence of divalent cations, and was blocked by mAb specific for two integrins, alpha E beta 7 and alpha L beta 2. After TGF-beta 1 treatment, cultured iIEL cell lines expressed alpha E beta 7 at levels similar to those found on iIEL in vivo. Under these conditions this integrin appeared to predominate in mediating the adhesion of iIEL to epithelial cells. Although alpha L beta 2 blocked the adhesion of iIEL to both endothelial and epithelial cells, alpha E beta 7 blocked binding only to epithelial cells suggesting that the ligand for alpha E beta 7 is not expressed on IL-1 beta-treated cultured endothelial cells. iIEL did not readily bind to the apical surface of confluent polarized epithelial cell monolayers. However, iIEL did bind to these cells when tight junctions were disrupted, a treatment that allows redistribution of proteins compartmentalized to the basolateral surface. This binding was also blocked by mAb to alpha E beta 7. In addition, in vitro coculture of iIEL with polarized epithelial cells resulted in basolateral localization of the iIEL. Thus, it is likely that expression of the alpha E beta 7 ligand is restricted to the basolateral membrane of polarized epithelial cells. Because alpha E beta 7 appears to be a predominant integrin on freshly isolated iIEL, we hypothesized that alpha E beta 7-mediated adhesion may be particularly important in cell-to-cell interactions between T cells and epithelial cells in vivo.

Alpha 4/180, a novel form of the integrin alpha 4 subunit

The integrin alpha 4 beta 1 (VLA-4) is a versatile cell-cell and cell-extracellular matrix adhesion receptor. The alpha 4 subunit can be expressed on the cell surface in two forms: an intact form (alpha 4/150) and a cleaved form (alpha 4/80,70). Here we have characterized a third form of alpha 4, called alpha 4/180. Although alpha 4/180 (M(r) 180, nonreduced) is different in size than alpha 4/150 (M(r) 150, nonreduced), these two forms are clearly related, as they (i) shared the same amino-terminal sequence, (ii) were both recognized in Western blots by an anti-alpha 4 COOH-terminal antiserum, (iii) migrated with the same apparent size and charge when reduced, and (iv) were both immunoprecipitated using anti-VLA-4 reagents. In pulse-chase experiments, precursors to both forms appeared simultaneously and matured at the same rate, indicating that one is most likely not the biosynthetic precursor of the other. Although reduction of alpha 4/180 to yield alpha 4/150 suggested the release of a cysteine-linked 30-kDa fragment, seven different biochemical techniques failed to identify such a fragment. Also, alpha 4/180 was converted to alpha 4/150 by incubation at pH 11, by treatment with EDTA at 56 degrees C, or by heating in the presence of elevated SDS levels. Together our findings suggest that alpha 4/180 and alpha 4/150 represent different conformations of the same alpha 4 polypeptide, with the former having anomalous slower migration in SDS-polyacrylamide gel electrophoresis. This unusual biochemical feature of alpha 4 is not shared by other beta 1-associated integrin alpha subunits and suggests that VLA-4 has unique structural properties.

Total skin electron beam radiation therapy for mycosis fungoides

Forty-nine patients with biopsy-proven mycosis fungoides, Stages I-IV were treated using total skin electron beam irradiation (TSEBI). Total dose ranged from 600 cGy to 3,200 cGy. To evaluate the dose response relationship, patients were retrospectively divided into two groups. In Group I, 18 patients received a dose of 2,000 cGy or less, and in Group II, 31 patients received more than 2,000 cGy. The overall response rate was 87.7% with a 75.7% complete response and 12.2% partial response. Complete response was higher among patients with early stage disease: (Stage IA 1/1, Stage IB 23/35 (92%), Stage IIA 3/4 (75%), Stage IIB 4/8 (50%), Stage III 3/6 (50%), Stage IVA 1/1, Stage IVB 0/1, and unstaged group 2/3 (66.6%)). Patients treated with a higher total dose had a higher overall 5-year survival rate (Group I 38%, Group II 68%), longer median duration of complete response (Group I, 27 months; Group II, 35.3 months), slightly better complete response rate (72.2% for Group I, 77.4% for Group II), and lower recurrence rate (Group I, 94%; Group II, 83.9%) compared to patients with lower total dose. Complications from TSEBI were minimal. Total skin electron beam irradiation is effective in controlling early stage mycosis fungoides; however, a prospective study to evaluate optimum total dose is needed.

A family of beta 7 integrins on human mucosal lymphocytes

The heterodimeric protein complex recognized by the human mucosal lymphocyte 1 (HML-1) monoclonal antibody is expressed on 95% of intraepithelial lymphocytes but on only 1-2% of peripheral blood lymphocytes [Cerf-Bensusson, N., Jarry, A., Brousse, N., Lisowska-Grospierre, B., Guy-Grand, D. & Griscelli, C. (1987) Eur. J. Immunol. 17, 1279-1285]. We purified the smaller HML-1 subunit (105 kDa under nonreducing conditions) from hairy-cell leukemia cells and determined the N-terminal amino acid sequence of this chain. The 17 residues determined were identical to the deduced amino acid sequence encoded by an integrin beta 7 cDNA clone [Yuan, Q., Jiang, W.-M., Krissansen, G.W. & Watson, J.D. (1990) Int. Immunol. 2, 1097-1108]. Biochemical analysis of the larger HML-1 subunit (175 kDa under nonreducing conditions) suggested that it was a distinct member of the cleaved group of integrin alpha chains, which we designated alpha E. The beta 7 chain also was associated with the integrin alpha 4 subunit, suggesting that the HML-1 antigen (alpha E beta 7) and alpha 4 beta 7 constitute a beta 7 integrin family on mucosal lymphocytes. Interestingly, regulation of the expression of the HML-1 antigen was reciprocal to that of lymphocyte function-associated molecule 1 in the presence of transforming growth factor beta 1. We suggest that these beta 7 integrins may play a specific role in mucosal localization or adhesion and that the expression of the HML-1 antigen might be regulated by transforming growth factor beta 1 produced at or near epithelial tissues.

Functional and structural analysis of VLA-4 integrin alpha 4 subunit cleavage

The cell surface heterodimer VLA-4 (alpha 4 beta 1), a member of the integrin family of adhesion receptors, is involved in both cell-extracellular matrix and cell-cell adhesion. Unlike any other integrin alpha subunit, the intact (150 kDa) alpha 4 subunit of VLA-4 can sometimes be cleaved into two noncovalently associated fragments (80 and 70 kDa). Using biosynthetic and mixing experiments, we found that human alpha 4 cleavage is a regulated, compartmentalized event, occurring soon after maturation of the beta 1-associated alpha 4 subunit. Cleavage of alpha 4, which is increased following T cell activation, has been suggested to correlate with altered VLA-4 functions. To address directly the functional importance of alpha 4 cleavage, we have studied VLA-4-mediated adhesion functions in cells expressing intact alpha 4 in comparison with cells expressing cleaved alpha 4. For this purpose, we first sequenced the N terminus of the endogenously produced 70-kDa alpha 4 fragment and identified the alpha 4 cleavage site between Lys557-Arg558 and Ser559. To abolish cleavage, we converted Arg558 to Leu or Lys557 to Gln by site-directed mutagenesis of the alpha 4 cDNA and then transfected both mutant and wild type alpha 4 cDNAs into VLA-4-negative K562 cells. Whereas transfection with wild type alpha 4 cDNA yielded predominantly cleaved alpha 4 subunit, the Leu558-alpha 4 yielded only intact alpha 4 subunit, and Gln557-alpha 4 yielded mostly intact alpha 4 subunit. Transfectants with the intact or the cleaved alpha 4 were equally capable of engaging in VLA-4-dependent adhesion to vascular cell adhesion molecule-1 and to the Hep II fragment of fibronectin (40 kDa) and aggregated equally well in response to anti-alpha 4 antibodies. Thus, cleavage of the alpha 4 subunit in these transfectants did not alter any of the known VLA-4-mediated adhesion functions.

Evidence for extrathymic changes in the T cell receptor gamma/delta repertoire

The germline repertoire of variable genes for the TCR-gamma/delta is limited. This, together with the availability of several V delta-specific and a C delta-specific mAbs, has made it possible to assess differences in the TCR-gamma/delta repertoire in man. TCR-gamma/delta cells expressing particular V gene segments have been previously shown to be localized in different anatomical sites. In this study, analysis of TCR-gamma/delta V gene segment usage performed on subjects from the time of birth through adulthood revealed striking age-related changes in the TCR-gamma/delta repertoire in peripheral blood. V delta 1+ gamma/delta T cells predominated in thymus as well as in peripheral blood at birth and then persisted as a relatively constant proportion of CD3+ PBL. However, V delta 2+ gamma/delta T cells that constitute a small proportion of the CD3+ cells in thymus and in peripheral blood at birth, then expand and account for the major population of gamma/delta T cells in PBL in adults. No parallel postnatal expansion of V delta 2+ cells in the thymus was observed, even when paired thymus-peripheral blood specimens were obtained on subjects between the ages of 3 d and 8 yr. The subset of V delta 2+ lymphocytes that was expanded in peripheral blood expressed high levels of CD45RO suggesting prior activation of these cells, consistent with the possibility that their expansion might have resulted from exposure to foreign antigens or superantigens. In contrast, V delta 1+ T cells in PBL showed no comparable increase in relative numbers and were either negative or expressed only low levels of CD45RO. Consistent with evidence for extrathymic peripheral expansion of selective TCR-gamma/delta subsets, no link between MHC haplotype and differences in the TCR-gamma/delta V gene usage between individuals was apparent, and identical twins displayed TCR-gamma/delta variable gene segment phenotypes that were strikingly different from one another. The elements that determine the TCR-gamma/delta repertoire in individuals are not known. It is possible that both thymic selection and extrathymic factors may influence the peripheral repertoire. Recently, TCR-gamma/delta+ lymphocytes have been shown to expand markedly in peripheral lymphoid tissues and infectious lesions in response to mycobacterial antigens, and a correlation between mycobacterial responses and TCR-gamma/delta V gene usage has been shown in mice. The data presented here demonstrated peripheral age-related changes in the gamma/delta repertoire and point to the importance of extrathymic expansion of specific gamma/delta subsets in generating the human TCR-gamma/delta repertoire.

Oral manifestations of cutaneous T cell lymphoma

Oral manifestations of cutaneous T cell lymphoma (CTCL) have received little attention in the dermatologic literature. The authors report two patients with lingual lesions. The histologic features are similar to those of the glabrous skin. A review of the 22 previously reported cases indicate a shortened survival. A retrospective review of 82 patients with CTCL treated at the authors' medical center identified only three with oral involvement. Radiation therapy offers effective palliation for these lesions.

Expression of human T cell receptor-gamma delta structural forms

The human TCR-gamma delta occurs in three biochemically distinct forms (forms 1, 2bc, and 2abc). A 40-kDa TCR gamma-chain is disulfide-linked to the TCR delta-chain in form 1, whereas 40-kDa or 55-kDa TCR-gamma polypeptides are noncovalently associated with the TCR delta-chain in forms 2bc and 2abc, respectively. Sequence analysis of TCR-gamma cDNA clones indicates that form 1 utilizes the C gamma 1 gene segment, whereas forms 2bc and 2abc appear to use allelic C gamma 2 gene segments containing either two copies (b and c) or three copies (a, b, and c) of the CII exon, respectively. We transfected TCR-gamma cDNA encoding form 1 or form 2abc into the MOLT-13 cell line that expresses form 2bc. The transfected TCR gamma-chains associate with the resident MOLT-13 TCR-delta, normally part of form 2bc, to yield CD3-associated TCR-gamma delta heterodimers identical to those seen on the donor cell lines (form 1 or 2abc). These transfection experiments show directly that, 1) when a single TCR-delta subunit is available, the presence or absence of disulfide linkage between TCR gamma- and TCR delta-chains is controlled by the TCR gamma-chain, and 2) the difference in the amount of N-linked carbohydrate attached to the transfected TCR-gamma proteins of form 2bc vs form 2abc is influenced by the presence or absence of CII exon copy "a" which appears to alter the secondary and/or tertiary structure of these TCR gamma-chain constant regions, thereby affecting the attachment of N-linked glycans. In contrast to the similar structure and usage of C beta 1 and C beta 2, TCR-gamma delta forms show striking differences in structure and are not equally represented in peripheral blood. Although the role of each form is unknown, it is possible that variable or joining-gene segment selection events or functional differences account for their unequal usage.

Expression of human T cell receptor-gamma delta structural forms

The human TCR-gamma delta occurs in three biochemically distinct forms (forms 1, 2bc, and 2abc). A 40-kDa TCR gamma-chain is disulfide-linked to the TCR delta-chain in form 1, whereas 40-kDa or 55-kDa TCR-gamma polypeptides are noncovalently associated with the TCR delta-chain in forms 2bc and 2abc, respectively. Sequence analysis of TCR-gamma cDNA clones indicates that form 1 utilizes the C gamma 1 gene segment, whereas forms 2bc and 2abc appear to use allelic C gamma 2 gene segments containing either two copies (b and c) or three copies (a, b, and c) of the CII exon, respectively. We transfected TCR-gamma cDNA encoding form 1 or form 2abc into the MOLT-13 cell line that expresses form 2bc. The transfected TCR gamma-chains associate with the resident MOLT-13 TCR-delta, normally part of form 2bc, to yield CD3-associated TCR-gamma delta heterodimers identical to those seen on the donor cell lines (form 1 or 2abc). These transfection experiments show directly that, 1) when a single TCR-delta subunit is available, the presence or absence of disulfide linkage between TCR gamma- and TCR delta-chains is controlled by the TCR gamma-chain, and 2) the difference in the amount of N-linked carbohydrate attached to the transfected TCR-gamma proteins of form 2bc vs form 2abc is influenced by the presence or absence of CII exon copy "a" which appears to alter the secondary and/or tertiary structure of these TCR gamma-chain constant regions, thereby affecting the attachment of N-linked glycans. In contrast to the similar structure and usage of C beta 1 and C beta 2, TCR-gamma delta forms show striking differences in structure and are not equally represented in peripheral blood. Although the role of each form is unknown, it is possible that variable or joining-gene segment selection events or functional differences account for their unequal usage.