Search

Monocyte (MN) surface human leukocyte antigen DR was examined in 10 patients with pulmonary tuberculosis (TB) and 12 healthy individuals using OK11, a mouse monoclonal antibody to human DR, in a 51Cr-release cytotoxicity assay. Of freshly isolated MNs from TB patients, 39.1% +/- 4.4% (mean +/- SEM) were DR+, compared with 57.2% +/- 5.7% in healthy subjects (P less than 0.02). After 24 hr in culture, a sharp rise was observed in the TB group, to 78.1% +/- 11.6% (P less than 0.005), compared with 64.9% +/- 5.1% in the control group. The TB patient group could be subdivided on the basis of tuberculin purified protein derivative-induced [3H]thymidine incorporation in peripheral blood mononuclear cells (PBMCs). A significantly smaller fraction of MNs from tuberculin nonresponder TB patients was DR+ (34.6% +/- 6.0%) compared with healthy controls (59.4% +/- 8.6%; P less than 0.05). In the nonresponder group, a greater fraction of PBMCs was identifiable as MNs by cytochemical techniques (51.2% +/- 3.6% vs 38.0% +/- 5.0% in the responder group; P less than 0.02). Cell mixing experiments demonstrated increased suppressor activity of DR- MNs.

Lymphocyte blastogenic responses to O. volvulus antigen (Oncho Ag), SKSD, and the mitogen PHA were tested in three groups of persons: light to moderately infected persons (INF); previously exposed but uninfected persons (EXP) and normal controls (NC). The exposed group showed significant responsiveness to Oncho Ag (delta ct/min = 6,002 +/- 1,375), while the infected (delta ct/min = 943 +/- 418) and normal control (delta ct/min = 428 +/- 418) groups did not. The mean blastogenic response to SKSD were EXP, 8,644 +/- 5,249; NC 6,039 +/- 2,880; INF, 2,619 +/- 1,012. The reduced reactivity in the INF group to Oncho Ag showed a significant correlation with reactivity to SKSD (P less than 0.05). To elucidate the mechanism of hyporesponsiveness in the infected group rigorous adherent cell depletion, by adherence to plastic followed by a nylon wool column, was utilized. When 20% plastic adherent cells were added back to the T cells prepared in this fashion, the mean blastogenic response to SKSD was significantly augmented (P less than 0.01). In contrast, the responsiveness to Oncho Ag was not significantly altered. The addition of indomethacin (1 microgram/ml) or autologous plasma had no significant effect on reactivity to either SKSD or Oncho Ag. There were no significant differences in the mean reactivity of the three groups to PHA-M (delta ct/min EXP 78,514 +/- 12,564; INF 62,393 +/- 14,447; NC 61,423 +/- 4,465). These results suggest that O. volvulus infection is associated with decreased lymphocyte reactivity to both parasite related and unrelated antigens, and imply that the mechanism for the two types of hyporesponsiveness may be distinct. While a weakly adherent suppressor cell may account for non-specific hyporesponsiveness, the mechanism of parasite specific decreased reactivity remains unknown.

Pharyngitis, bronchitis, and pneumonia represent the most common respiratory tract infections. With a view to establishing effective management strategies, the origins of these illnesses and the diagnostic techniques that have been developed to discover them are reviewed. Therapeutic regimens with documented efficacy are outlined with emphasis on specific rather than empiric treatment. Although many respiratory tract pathogens remain exquisitely sensitive to penicillin, the emergence of resistant strains underscores the need for safe and effective alternative therapies.

Many inflammatory stimuli increase both in vitro granulocyte adhesiveness and motility. The present investigation compared the effects of bacterial products on in vitro granulocyte adherence to nylon fiber and granulocyte motility. Escherichia coli endotoxin and Staphylococcus aureus and E. coli culture filtrates enhanced both motility and granulocyte adherence to nylon. Column chromatography of S. aureus culture filtrate demonstrated that similar molecular weight components stimulated both motility and granulocyte adherence. In contrast, endotoxin stimulated granulocyte adherence but not chemotaxis in plasma-free medium. In addition, a group D streptococcal culture filtrate enhanced motility but not adhesiveness of plasma-free granulocytes. These studies indicate that inflammatory stimuli may interact with granulocytes in concert to enhance both adhesiveness and motility, or they may interact independently to stimulate one in vitro function preferentially.

We examined stimulation of monocyte (MN) release of interleukin 1 (IL 1) by soluble microbial products. MN from tuberculin skin test nonreactive donors incubated with PPD (100 micrograms/ml) released IL 1 activity of 80.5 +/- 33.9 U/ml (mean +/- SD, n = 6), similar to that induced by optimal concentrations of LPS (76.4 U/ml). OKT3-reactive cells were not required for this process. PPD-stimulated IL 1 release by MN did not appear to be due to endotoxin contamination, as 1) PPD contained 0.01% endotoxin, 2) MN incubated in LPS (0.1 micrograms/ml) produced 19.5 +/- 13.9 U/ml, significantly less than PPD (p = 0.03), and 3) addition of polymyxin B (12.5 micrograms/ml) abrogated IL 1 production in response to LPS (0.1 microgram/ml) but had no significant effect on PPD induction of IL 1. Antigen 5, a partially purified cytoplasmic antigen of Mycobacterium tuberculosis, had similar IL 1-inducing effects. Arabinogalactan (a mycobacterial polysaccharide), streptolysin O, and tetanus toxoid did not. Thus, mycobacterial protein antigens directly stimulate MN to release IL 1. This property may be central to the response of the naive host to mycobacterial infection and may play a pathophysiologic role in tuberculosis.

Interleukin-1 (IL-1) production by blood monocytes and blastogenesis produced by tuberculin purified protein derivative (PPD) in blood T lymphocytes were examined in patients with pulmonary tuberculosis. Monocytes were isolated from blood mononuclear cells by plastic adherence, and IL-1 activity was determined in the mouse thymocyte proliferation assay. Monocytes from patients with tuberculosis produced significantly higher activities of IL-1 than did those from healthy tuberculin reactors when stimulated with lipopolysaccharide (LPS) (patients, 56.1 +/- 20.0 U/ml; healthy control subjects, 7.3 +/- 1.7 U/ml; p less than 0.05) or PPD (patients, 28.1 +/- 7.2 U/ml; healthy control subjects, 9.5 +/- 2.9 U/ml; p less than 0.05). In contrast, PPD-induced blastogenic responses in peripheral blood mononuclear cells (PBMC) from the patients were lower than those from healthy subjects (patients, 4,506 +/- 1,145 cpm; healthy control subjects, 14,655 +/- 2,240 cpm; p less than 0.005), and IL-1 production by monocytes showed a positive correlation with monocyte suppressor activity for PPD-induced blastogenesis. Moreover, exogenous IL-1 was capable of suppressing antigen-induced blastogenesis of PBMC from healthy subjects. These data suggest that monocytes from patients with pulmonary tuberculosis are activated to produce or secrete increased levels of IL-1 and that IL-1 may be a mediator of suppressor cell function.

Studies correlating quantitative aspects of the handling of dinitrophenyl guinea pig albumin (DNP-GPA) by guinea pig macrophages with the potential of cell-associated antigen to initiate proliferation of immune T lymphocytes have examined the nature of immunologically relevant antigen. After the loss of 75% of cell-bound DNP-GPA during the first 24 hr of in vitro culture, the remaining antigen persists qualitatively unchanged throughout further culture. However, coincident immunogenicity of the macrophage-associated NDP-GPA progressively deccreases, suggesting loss of accessibility of the antigen to responding immune lymphocytes. There is a small, stable, surface antigen pool but these studies suggest that the immunologically critical fraction of DNP-GPA, as regards guinea pig T cell activation, is resistant to trypsinization and inaccessible to antibody.

In neutrophil-mediated killing of schistosomula, antibody and serum complement serve two functions: (i) opsonization of the target pathogen and (ii) generation of cell-activating, chemotactic peptides. We studied neutrophil-mediated schistosomulum killing in experiments designed to isolate these functions of antibody and complement in the cell activation response of neutrophils to external pathogens. Schistosomula opsonized by antibody or antibody plus complement induced neutrophil-mediated killing, while complement-opsonized larvae did not. Antibody enhancement of cell-mediated killing correlated with increased cell-to-parasite adherence, while cell-mediated killing in the presence of fresh normal human serum (providing chemotactic factor stimulation and complement opsonization of larvae) demonstrated a dissociation between neutrophil adhesive and killing responses. Exogenous chemotactic stimuli were found to enhance significantly neutrophil-mediated killing of both opsonized and unopsonized larvae. Experiments involving parabiotic chambers confirmed that chemotactic-factor-stimulated neutrophils may cause significant parasite mortality without direct cell-parasite contact. In further analysis of the neutrophil response to surface and fluid-phase stimulation, release of neutrophil cytotoxic mediators was found to vary according to the type of stimulus provided: cell exposure to either larvae opsonized by antibody plus complement or to chemotactic factors provoked low-to-moderate cell release of superoxide anion, granule enzymes, and arginase; when opsonic and chemotactic stimuli were combined, a greater-than-additive secretory response was noted. Under such maximal stimulation, oxidative and nonoxidative mediators were synergistic in effecting neutrophil-mediated parasite killing. The primary function of complement in cell-mediated parasite killing appears to be to promote chemotactic-factor-mediated cellular release of toxic agents and not cell-target linkage, whereas antibody-mediated adherence is associated with concurrent cellular activation. Both neutrophils adherent to the antibody-opsonized schistosomulum and chemotactic-factor-stimulated cells (adherent and not adherent to the parasite) appear to contribute significantly to its demise.

In a review of endocarditis caused by fastidious, slow-growing gram-negative rods, similarities in the spectrum of disease overshadow differences among cases grouped by specific organisms. Cardiobacterium hominis, Actinobacillus actinomycetemcomitans and Haemophilus species usually seed previously damaged cardiac valves presumably during bacteremia from an upper respiratory site. The clinical presentation resembles that of Streptococcus viridans endocarditis and is usually subacute or chronic. Despite bacteriologic cure, severe CHF and/or systemic embolization frequently develops during or following the course of antibiotics, resulting in significant morbidity and a high mortality rate. This report of nine cases diagnosed at five hospitals in a 7-year period suggests that endocarditis due to these organisms is more common than previously appreciated and frequently goes unrecognized. This is probably due to a lack of attention to the requirements for culture of this group of bacteria with propensity for granular growth in broth. We have proposed specific cultural techniques appropriate to the search for these organisms in patients with apparent culture-negative endocarditis.

In health, pulmonary alveoli are maintained free of inflammatory responses to inhaled foreign antigens. The specific role of alveolar macrophages (AM) in modulating the local cellular immune response to antigens is controversial. Immunoregulatory function and properties of AM and blood monocytes (MN) were compared. The AM were obtained by bronchoalveolar lavage of healthy volunteers, MN by adherence of peripheral blood mononuclear cells to plastic. These accessory cells were added in increasing ratios to a responder population rendered rigorously accessory cell-dependent by nylon wool adherence and depletion of cells bearing the surface Class II MHC determinant, HLA-DR. At low ratios of mononuclear phagocytes to lymphocytes (less than or equal to 1:10), MN and AM supported significant and comparable blastogenic responses to tetanus toxoid (3H-thymidine incorporation at a 1:10 ratio was 9,697 +/- 2,508 for MN and 8,969 +/- 1,454 for AM, mean cpm +/- SE, n = 9, p = NS) and other antigens. Interleukin-1 (IL-1) activity in supernatants of MN stimulated with lipopolysaccharide (LPS), 10 micrograms/ml, was 115 +/- 28 versus 67 +/- 21 U/ml in supernatants of AM (n = 9, p greater than 0.2). At suboptimal concentrations of LPS, however, MN expressed more IL-1 activity than did AM. The specific mean fluorescence intensity of surface expression of HLA-DR determinants as assessed by flow cytometry was similar for MN and AM. At the higher ratio of 1:2, MN supported 32% increased responses to tetanus toxoid compared with that at 1:5 (p less than 0.05). In contrast, AM at a ratio of 1:2 suppressed lymphocyte response by 69% (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

We conducted a prospective, randomized, double-blind comparison of intravenous penicillin and cefamandole in the therapy of pneumococcal pneumonia. Patients received either 1 g of cefamandole or 600,000 U of aqueous penicillin G every 6 h. Of the 100 patients entered into the study, 96 had clinical and radiographic evidence of pneumonia. Microbial etiology was determined from the results of sputum and blood cultures and/or sputum Gram stains. Streptococcus pneumoniae was pathogenic in 49 patients, of whom 24 received cefamandole and 25 received penicillin. There was no statistically significant difference in the response or cure rate. Of the 100 patients, 93 were treated for 3 days or more and were evaluated for adverse effects and toxicity. There was no significant difference between cefamandole-treated and pencillin-treated patients in the incidence of colonization, superinfection, phlebitis, thrombocytosis, decrease in hematocrit, or elevated liver function tests. Eosinophilia occurred more frequently in patients treated with penicillin (20 of 42) than in those treated with cefamandole (11 of 42 (chi square, P < 0.05). Only one patient receiving cefamandole developed a positive direct Coombs test. No patient in either group developed meningitis. We conclude that, with the doses and route of administration employed in this study, cefamandole is as effective as penicillin in the therapy of pneumococcal pneumonia without an increased incidence of colonization, superinfection, or adverse effects.

Human NK activity is radiosensitive under the control of X-linked genes. We have evaluated the expression of these genes in other forms of cellular cytotoxicity. The NK radioresistant and radiosensitive phenotype is expressed in ADCC. Specific cellular cytotoxicity, generated in a MLC with a radiosensitive donor as responder, was radioresistant. NK-like activity recruited from nonadherent cells of radiosensitive subjects stimulated with allogenic cells, mitogens (PHA, Con A or PWM), or recall antigens (TT or PPD) was radioresistant. The acquisition of radioresistance was relatively rapid, beginning within 24 hr after exposure to PHA, prior to detectable proliferation. Radioresistance of MLR augmented NK-like activity was maximal 3 days after initiation of the culture. MLR augmented NK-like activity was spared by the immunosuppressive polypeptide antibiotic CsA at doses up to 1 micrometer/ml. CsA did, however, reduce acquisition of radioresistance by the NK-like activity at doses above 0.01 mu gm/ml, a concentration which does not inhibit uptake of 3H-thymidine but does reduce the level of specific CML. These data suggest that mitogens and antigens, including allogeneic cells, are recruiting radioresistant NK-like activity which can be distinguished from the radiosensitive spontaneous NK activity of the cell donor. Further, in the MLR, both radiosensitive and radioresistant NK-like activity may be recruited.

Three cases of congestive cardiomyopathy complicating the acquired immune deficiency syndrome (AIDS) are reported. In one case, acute cardiac decompensation resulted in prolonged but ultimately reversible cardiogenic shock. In the second case, clinical signs of cardiac disease were precipitated by acute renal failure and fluid overload. In the third, congestive heart failure developed spontaneously and responded promptly to administration of diuretics but the patient died suddenly, apparently due to an arrhythmia. The etiology of cardiomyopathy in AIDS is unclear and the manifestations of cardiomyopathy in this setting range from subclinical to life threatening.

The role of cytotoxic T lymphocytes in host defenses against infectious agents is unknown as these cells have not previously been demonstrated to kill microorganisms directly. We studied the cytotoxicity of T lymphocytes purified from peripheral blood mononuclear cells of healthy subjects for the multicellular schistosomula of Schistosoma mansoni. Unstimulated and phytohemagglutinin (PHA)-stimulated T cells were cultured with schistosomula at a 5,000:1 effector/target (E:T) ratio for 18 h at 37 degrees C. Unstimulated T cells killed 2.1 +/- 0.6% of schistosomula as judged by dye uptake and did not change their infectivity for mice. In contrast, PHA-stimulated T cells killed 41.3 +/- 3.1% of schistosomula by dye uptake and 56.7 +/- 7.7% of these organisms could not mature to adult worms in vivo. Killing was associated with and dependent on increased binding of PHA-stimulated T lymphocytes to schistosomula. Significant schistosomula killing first was noted after 2 h of exposure to T cells to PHA and peaked at 24; enhanced killing by PHA-stimulated cells was observed at an E:T ratio of 500:1 and was maximal at 5,000:1. Exposure of T lymphocytes to oxidative mitogens, soluble antigens, and alloantigens also resulted in enhanced killing of schistomula. These studies show that T lymphocytes activated by a variety of stimuli develop the capacity to kill schistosomula of Schistoma mansoni. Direct killing of infectious agents by cytotoxic T cells may contribute to host resistance to infections.

Previous studies from this laboratory demonstrated that adherent mononuclear cells selectively decreased in vitro tuberculin responses in some anergic patients with tuberculosis; subsequently this adherent suppressor cell was characterized as a monocyte. The current study of 41 patients with active pulmonary tuberculosis examined whether T cell subpopulations also acquired antigen-specific suppressor function during Mycobacterium tuberculosis infection, contributed to monocyte-mediated suppression of tuberculin responses, or both. Alteration in the numbers of circulating T-helper (Leu 3a) and T-suppressor (Leu 2a) cells was not observed in patients with tuberculosis, nor did Leu 2a cells selectively modulate in vitro tuberculin responses. The numbers of circulating T gamma cells, a subset of T cells identified by surface receptors for the Fc portion of IgG (Fc gamma R), was increased twofold in patients with active pulmonary tuberculosis. Depletion of T gamma cells from in vitro cell culture consistently and selectively increased tuberculin responsiveness of T cells from patients with tuberculosis. In addition, in the absence of T gamma cells, monocyte-mediated suppression of tuberculin responses was demonstrated in each patient observed. These studies demonstrate that during M. tuberculosis infection T gamma cells acquire antigen-specific suppressor cell activity and suggest that T gamma cells also contribution to immunoregulation modulating the expression of tuberculin-specific suppression by monocytes.

Two cases of cutaneous phycomycosis in the form of diabetic leg ulcers were diagnosed by culture and biopsy demonstration of invasive fungal infection. The first patient had an infected vesicular skin lesion. Systemic amphotericin B therapy and repeated debridement were curative. A posttraumatic leg ulcer developed in the second patient in the setting of hyperglycemia and renal insufficiency. Aggressive infection necessitated a curative amputation. Phycomycetes can cause or complicate diabetic leg ulcers and such infections may require biopsy for early recognition and subsequent successful therapy.

Intravesical administration of Bacillus Calmette-Guerin (BCG) causes a localized cell-mediated immune response. The intensity of this inflammatory response may be gauged by measuring the levels of both interleukin-2 (IL-2) and an inhibitor of interleukin-2 (IL-2-IN) activity in the urine during the hours after a BCG instillation. The levels of urinary IL-2 and IL-2-IN in the sixth week of BCG therapy predicted the subsequent clinical course in a group of 25 patients (P less than 0.01). Measurement of urinary IL-2 and IL-2-IN activity may be used to identify accurately those patients likely to develop a tumor recurrence, thereby sparing them the risk associated with inadequately treated bladder cancer. Since IL-2 and IL-2-IN are competitive with respect to biologic activity, and since relatively high urinary levels of either IL-2 or IL-2-IN activity correlated with a favorable clinical course, the authors conclude that the presence of bioactive IL-2 in urine is not required for the prevention of recurrent superficial bladder cancer.

We examined the potential contribution of thromboxanes in human monocyte adherence to plastic. Monocyte adherence to plastic could be augmented by various stimuli including lipopolysaccharide, chemotactic peptide, and supernates of antigen-stimulated lymphocytes. Increments in monocyte adhesiveness were suppressed by inhibition of cyclooxygenase, thromboxane synthetase, or by antiserum to thromboxane B2. Neither prostaglandin E2 or F2 alpha significantly affected baseline or lipopolysaccharide-stimulated monocyte adherence. Additional experiments confirmed incremental production of thromboxane B2 by monocytes after incubation with lipopolysaccharide. Thromboxane B2 itself did not stimulate monocyte adhesiveness. These data demonstrate that monocytes release thromboxane A2 following stimulation and suggest that thromboxane A2 may play a significant role in monocyte-substrate attachment.

Bacterial colonization of the tracheobronchial tree is a significant problem in hospitalized and chronically ill individuals. Colonization occurs because of both microbial and host factors, with the foremost mechanism being adherence of pathogenic gram-negative bacteria to mucosal epithelial cells. In the pathogenesis of nosocomial pneumonia, colonization appears to be an essential first step. In the diagnostic approach to hospital-acquired pneumonia, a distinction must be made between colonization and true lower respiratory tract infection. Future approaches to the major problem of colonization with gram-negative bacteria will require a better understanding of pathogenesis and employ strategies that not only focus upon limiting the bacterial pathogens but also attempt to improve upon pulmonary defense mechanisms.

Immunosuppressive mechanisms loom as important factors in depression of delayed-type hypersensitivity responses during active tuberculosis. Nonspecific suppression may be mediated by circulating immune complexes containing mycobacterial polysaccharides such as D-arabino-D-galactan. The mechanism of suppression involves activation of monocyte production of immunosuppressive prostaglandin E2. Peripheral blood mononuclear cells from patients with tuberculosis include increased numbers of monocytes that suppress the response to tuberculin purified protein derivative (PPD). Antigen-specific suppression is associated with monocyte activation by a number of criteria, including decreased surface expression of HLA-DR determinants and increased production of interleukin 1 (IL-1). The increased production of IL-1 is associated with--and may have a causal relation to--immunosuppression. A second parallel regulatory mechanism involves PPD-specific suppression by Fc gamma receptor-bearing lymphocytes. The consequence of these immunosuppressive circuits is depression of tuberculin-induced blastogenesis, production of IL-2, and generation of IL-2 receptors. These findings suggest that natural infection with Mycobacterium tuberculosis may result in immunosuppression. Studies of potentially protective antigens in experimental systems must be designed to assess and avoid activation of suppressor circuits.

Tuberculous pleurisy results when a subpleural nodule discharges mycobacterial antigens into the pleural space of a hypersensitive host. The clinical syndrome is a reflection of an in situ delayed-type hypersensitivity reaction in which plasma proteins are exuded into the pleural space and T-helper cells accumulate, proliferate, and produce, and release inflammatory mediators. The immune response initially contains the local infection, but in the absence of therapy, the host is at great risk of developing tuberculosis during the next 5 years. The focal accumulation of vigorously responsive T-helper cells and activated B cells in the pleural space may prove useful in identifying mycobacterial constituents which are immunogenic and possibly candidate vaccine antigens.

The effects of ultraviolet-B radiation (UV-B) on accessory function of human blood adherent mononuclear cells (ADH) for antigen and mitogen-induced responses, and production by ADH of the amplifying cytokine interleukin 1 (IL-1) were examined. Responder lymphocytes were rendered accessory cell dependent by treatment of nonadherent cells with OKIal+complement. UV-B depressed accessory function of ADH in a dose-dependent manner. UV-B at 5 mJ/cm2 decreased accessory function of 2 x 10(4) ADH for tetanus toxoid-induced responses (measured as incorporation of 3H-thymidine) by 84% (P less than 0.001, n = 6) and phytohaemagglutinin-induced responses 91% (P less than 0.001, n = 4). UV-B also decreased accessory activity of peripheral blood mononuclear cells but not Epstein-Barr virus-transformed B cells for a PPD-reactive T cell line. Viability was approximately 90% 0-72 h after exposure of ADH to 5 mJ/cm2 of UV-B. Interleukin 1 (IL-1) activity of supernatants of ADH was assayed on C3H/HeJ mouse thymocytes. Pretreatment of ADH with 5 mJ/cm2 UV-B decreased lipopolysaccharide-stimulated IL-1 activity from 169 +/- 34 (mean U/ml +/- s.e.) to 4 +/- 1 (P less than 0.01, n = 4). Lysates of UV-B irradiated. LPS-stimulated ADH had no discernible IL-1 activity. Addition of IL-1 partially restored accessory activity of UV-B irradiated ADH for lymphocyte responses to TT. Exposure of ADH to TT or PHA for 30 min before irradiation blocked the inhibitory effect of UV-B on accessory activity. Thus, low doses of UV-B are deleterious to accessory function and to production of IL-1 by ADH. Interference with production of cytokines and with initial interactions of accessory cells with antigen and mitogen may be critical to the effects of UV-B on immunoregulatory function of ADH.

Patients with newly diagnosed, pulmonary tuberculosis had a tuberculin-specific defect in IL-2 production. Mean PPD-induced IL-2 activity was 81.2% lower in patients as compared with healthy tuberculin reactors. PPD-induced expression of T cell IL-2 receptors was 5.9 times less in peripheral blood mononuclear cells of patients with tuberculosis as compared with healthy tuberculin reactors. Furthermore, purified IL-2 failed to correct PPD-induced blastogenesis in patients. Suppression by adherent cells was operative in one group of patients; adherent cell depletion increased their T cell production of IL-2 7.2-fold. A second group of patients with low IL-2 production did not have suppressor adherent cells and were clinically distinct, with more extensive disease on chest x ray. The basis for low IL-2 production in such individuals is unknown. Disordered regulation of IL-2 metabolism may be a key feature in the depressed cellular immune response of tuberculosis.

Ten confirmed cases of left-sided endocarditis due to Pseudomonas aeruginosa were reported in detail and the English literature was reviewed. In recent years, venous access (usually illicit) has been the major predisposing factor to this infection and abuse of pentazocine and tripelennamine has been particularly associated with endocarditis due to this organism. This infection involves previously damaged as well as normal valves. The development of congestive heart failure did not adversely affect the prognosis of this infection. However, the development of azotemia was associated with a greater likelihood of a fatal outcome. In the current series, deaths were due to uncontrolled infection. This often occurred despite inhibitory and bactericidal activity in serum generally considered adequate for treatment of endocarditis. Medical treatment alone rarely produced cure of infection. Our experience with a high frequency of major vessel embolization (4/10) and the improved survival after medical/surgical treatment suggests that prompt valve replacement combined with high doses of an aminoglycoside plus carbenicillin or ticarcillin provide the best opportunity for successful outcome in patients with left-sided endocarditis due to P. aeruginosa.

Human peripheral blood mononuclear cells (PBMC) were preincubated for 3 days in medium alone or with various mitogens then washed and irradiated. The preincubated cells then were cultured with autologous T-cells in an autologous mixed lymphocyte reaction (AMLR). Staphylococcal protein A (SPA) pretreatment of PBMC enhanced autologous T-lymphocyte proliferation from 1375 +/- 321 cpm (mean +/- SEM untreated PBMC) to 42,467 +/- 7,985 cpm (SPA primed PBMC) (p less than 0.01). The ability of SPA treated PBMC to enhance the AMLR was not simply a reflection of their proliferation in preculture, as PBMC precultured with phytohemagglutinin and concanavalin A showed greater proliferation than SPA-treated PBMC yet only minimally enhanced the AMLR. Kinetic studies and pre-exposure of PBMC to graded doses of gamma radiation showed that SPA augmentation of the AMLR was mediated by 2 components which differed in kinetics and radiosensitivity. Although incubation of PBMC with SPA did not increase the percentage of cells with detectable surface Ia antigen, SPA did increase the density of Ia in the preincubated cells. Cell separation studies revealed that SPA enhancement of the AMLR was not mediated by T-cells, but was mediated by a non-adherent non-E-rosetting fraction of cells. SPA enhancement of the AMLR was associated with an increased Ia density in the stimulator population but not with an increase in Ia positive cells and was mediated by proliferation-dependent and proliferation-independent mechanisms.

We observed that lymphocytes obtained from healthy persons generally expressed infrequent reactivity with the monoclonal antibody 4D12, an antibody raised against a cell line infected by the human T-lymphotropic virus type I. As had been observed previously, persons bearing HLA-B5 cross-reactive antigens and certain other allotypes had frequent lymphocyte reactivity with 4D12. Lymphocytes obtained from persons infected by the human immunodeficiency virus were highly reactive with 4D12 as were lymphocytes obtained from persons with other viral or bacterial infections. Flow cytometric studies revealed greater 4D12 reactivity by larger lymphocytes, and in vitro studies demonstrated that lectin-stimulated lymphocytes acquired 4D12-reactive antigens. There was also a significant correlation between expression of 4D12-reactive antigens and the presence of the interleukin-2 receptor as recognized by the monoclonal antibody anti-Tac. Thus, the monoclonal antibody 4D12 recognizes a lymphocyte surface antigen frequently expressed among persons with various acute and chronic infections. This antigen is a marker of lymphocyte activation.

In human tuberculosis, adherent mononuclear cells (AMC) selectively depress in vitro responses to the mycobacterial antigen tuberculin purified protein derivative (PPD). The phenotype of this antigen-specific adherent suppressor cell was characterized by examining the functional activity of adherent cells after selective depletion of sheep erythrocyte-rosetting T cells or OKM1-reactive monocytes. Adherent cell suppression was studied in the [3H]thymidine-incorporation microculture assay by using T cells rigorously depleted of T cells with surface receptors for the Fc portion of IgG (T gamma cells) as antigen-responsive cells. PPD-induced [3H]thymidine incorporation by these non gamma T cells was uniformly reduced (mean, 42% +/- 10% [SD]) when autologous AMC were added to non gamma T cells at a ratio of 1:2. Antigen-specific suppression by AMC was not altered by depletion of sheep erythrocyte-rosetting T cells or treatment with indomethacin. However, AMC treated with OKM1 and complement or gamma irradiation (1,500 rads) no longer suppressed tuberculin responses in vitro. These studies identify the antigen-specific adherent suppressor cell in tuberculosis as an OKM1-reactive, non-erythrocyte-rosetting monocyte. The radiosensitivity of this monocyte immunoregulatory function may facilitate its further definition.

It is not clear whether the accessory function of monocytes from subjects with human immunodeficiency virus (HIV)-related diseases such as acquired immunodeficiency syndrome (AIDS) and persistent generalized lymphadenopathy (PGL) is intact. In this study, the accessory function of monocytes from healthy subjects (n = 9) and subjects with AIDS (n = 4) and PGL (n = 5) was assessed by adding graded numbers of monocytes to lymphocytes stimulated with either tetanus toxoid or phytohemagglutinin. By nonparametric analysis, it was determined that a significantly greater number of monocytes was required for half-maximal responses of lymphocytes from subjects with PGL (for tetanus toxid but not phytohemagglutinin) and from those with AIDS, compared with healthy subjects. To address whether this observed difference was a result of a defect in accessory function of monocytes or a result of altered responsiveness of lymphocytes, a mixing experiment was performed between monocytes and lymphocytes obtained from a patient with PGL but without symptoms and an HLA-D-matched healthy sib. Dysfunction of both monocytes and lymphocytes was evident. Thus, this report provides data that monocytes in HIV infection are defective in accessory function for lymphocyte responses to soluble stimuli. We speculate that such dysfunction of monocytes may contribute to the progressive disturbance of the immune response that occurs during HIV infection.

We examined the role of prostaglandins and thromboxanes as mediators of plasma-dependent increased polymorphonuclear leukocyte adhesiveness induced by Escherichia coli lipopolysaccharide. The cyclo-oxygenase inhibitors-indomethacin and d,l-6-chloro-alpha-methyl-carbozole-2-acetic acid (R020-5720)-reduced lipopolysaccharide-induced adherence of polymorphonuclear leukocytes by 74 and 62%, respectively. In addition, inhibitors of thromboxane synthetase-imidazole, 9,11-azoprosta-5,13-dienoic acid, and 1-benzylimidazole-suppressed the stimulation of adherence by 31, 66, and 83%, respectively. Exogenous prostaglandins E(1), E(2), and F(2)alpha did not increase polymorphonuclear leukocyte adherence, nor were they detected in significant quantities in supernates of polymorphonuclear leukocytes exposed to lipopolysaccharide. However, inhibitors of both cyclo-oxygenase and thromboxane synthetase reduced increases in adherence induced by arachidonic acid (10 mug/ml), suggesting that lipopolysaccharide-mediated increases in adherence were due to an arachidonic acid product other than prostaglandin E(2) or F(2)alpha. 8,11,14-Eicosatrienoic acid, a precursor of monoenoic prostaglandins, did not enhance polymorphonuclear leukocyte adhesiveness. We next demonstrated lipopolysaccharide-stimulated generation, by polymorphonuclear leukocytes, of a labile, low molecular weight, dialyzable substance capable of enhancing the adherence of unstimulated leukocytes. In parallel experiments, a 10-fold increase in immunoreactive thromboxane B(2) over basal levels was detected after exposure of leukocytes to lipopolysaccharide. The inhibition of lipopolysaccharide enhancement of adherence by specific rabbit antibodies to thromboxane B(2) strongly supported a primary role for thromboxane A(2) as the mediator of the observed increases in adherence. Lipopolysaccharide-stimulated purified platelets did not increase leukocyte adherence, whereas thrombin-stimulated platelets did increase adherence. These studies suggest that lipopolysaccharide stimulates polymorphonuclear leukocytes to produce thromboxane A(2), which enhances their adhesiveness to nylon.

The kinetics of aminoglycoside elimination were determined in 18 hospitalized narcotics abusers receiving gentamicin or tobramycin for treatment of severe infection. Rapid aminoglycoside elimination (requiring doses of greater than 5 mg/kg per day to maintain adequate drug levels) was noted in 12 of the 18 patients (18 of 27 clearance studies). Patients found to have rapid elimination were younger (P less than 0.01) and had larger drug distribution volumes (P less than 0.005), greater measured creatinine clearances (P less than 0.05), and lower creatinine levels in serum (P less than 0.001) than those with normal elimination. Nevertheless, by regression analysis, age, creatinine levels in serum, creatinine clearances, and drug distribution volumes proved to be unreliable predictors of individual aminoglycoside clearance. Measured drug half-life in serum appeared to be the only reliable predictor of drug clearance (r = 0.93). Patients with rapid drug elimination had aminoglycoside clearances 16 to 43% greater than measured creatinine clearances, suggesting an extraglomerular route of drug elimination. We conclude that in drug abuse patients a significant and clinically unpredictable interpatient variation occurs in aminoglycoside elimination and that accurate serum kinetics are needed to determine therapeutic dosing. In addicts younger than 35 years, with a creatinine level of less than 1.0 mg/100 ml in serum, the risk of inadequate therapy is high if standard dosing guidelines are followed. For this group, initial dosing of 8 mg/kg per day, with a drug half-life determination on the first dose, is recommended. Pharmacokinetic analysis is critical for all drug abusers treated with aminoglycosides for serious infection.

In vitro exposure of peripheral blood lymphocytes (PBLs) to doses of ultraviolet radiation (UVR) achievable during recreational sun exposure produces profound inhibition of lymphocyte blastogenesis. This study demonstrates that this inhibition is mediated by a direct dose-dependent effect on populations enriched for T-lymphocytes and is reversible after incubation of responder cells with phytohemagglutinin (PHA). In contrast, monocyte accessory function for both antigen- and mitogen-induced proliferation is relatively unaffected by in vitro exposure to UVR at doses up to 30 mJ/cm2. Exposure of PBL to UVR also results in the induction of a suppressor mechanism that inhibits the proliferation of unirradiated PBLs. In vitro exposure of human blood cells to UVR may provide a valuable tool for examining the cellular basis for the immunosuppressive effects of UVR.

Guinea pig macrophages can take up sufficient 2,4 dinitrophenyl guinea pig albumin during a brief in vitro exposure at 37 degrees C to trigger proliferation and lymphokine production with primed T lymphocytes on subsequent co-culture. Treatment of such antigen-bearing macrophages with trypsin, a procedure which removes surface antigen, does not alter the ability of such macrophage to initiate the release of migration inhibition factor from sensitized T lymphocytes. In addition, formation of antigen-specific rosettes between primed T cells and antigen-bearing macrophages is not blocked by high concentrations of antibody directed against the antigen mediating this interaction. Similarly, primed T lymphocyte DNA synthesis induced by antigen-bearing macrophages is not inhibited by specific antibody to that antigen. These data support the conclusion that the fraction of macrophage-associated antigen which is relevant to T lymphocyte activation does not reside on the macrophage surface but rather remains in a restricted compartment from which it is accessible to the T cell but unavailable to either blockade by specific antibody or removal by proteolytic enzymes.

Fifteen cases of Haemophilus influenzae (HI) meningitis in adults occurring of Cleveland during the last 11 years are presented. The majority of patients had factors predisposing to infection such as otitis, pneumonia, diabetes or alcoholism. In addition, 7 of the 15 patients developed meningitis at various intervals following head trauma and neurosurgery, and 3 patients required dural repairs for CSF rhinorrhea. The diagnosis of meningitis may be difficult to establish resulting in delay in appropriate therapy in some cases. Nuchal rigidity was absent frequently; CSF lymphocytosis can be seen initially. The CSF Gram stain may be negative or the pleomorphic nature of the organism on Gram-stain may make distinction from other gram-negative organisms difficult. The majority of patients had meningitis due to non-Type B HI in contrast to previous reports of this illness in children and adults. One of our patients had beta-lactamase producing HI isolated from CSF. We believe that chloramphenicol should be included in the initial empiric therapy for adults with meningitis and gram-negative coccobacillary rods on Gram-stain or negative CSF Gram-stains.

A single-cell assay was utilized to study the augmentation by Escherichia coli lipopolysaccharide (LPS) of the cytotoxicity of human lymphocytes for the human myeloid tumor K562. Preincubation with LPS at 20 micrograms/ml for 30 min at 37 degrees increased the binding of all nonadherent (NA) lymphocyte populations to K562 tumors [unseparated NA lymphocytes from 13.1 to 25.1%, immunoglobulin G Fc receptor-enriched lymphocytes from 27.6 to 42.9%, and immunoglobulin G Fc receptor-depleted lymphocytes from 14.0 to 23.7%, at p less than 0.001]. In contrast, interferon (IFN) at 10 units/ml had no effect on the overall binding of lymphocytes to K562 tumors. When lymphocyte-tumor conjugates were dispersed in agarose, cytotoxic activity of unseparated NA lymphocytes at 1 to 3 hr was markedly increased by preincubation with LPS (p less than 0.001). However, LPS did not enhance cytotoxicity if conjugates were formed in its absence. IFN, likewise, increased cytotoxic activity in unseparated NA lymphocytes at 1 to 3 hr (p less than 0.001). No synergistic cytotoxicity was seen with concurrent exposure to LPS and IFN. LPS increased cytotoxicity in the Fc receptor-enriched:tumor conjugates at 1 to 3 hr (p less than 0.001) and appeared to promote more efficient killing in individual conjugates over time. Cytotoxicity in the Fc receptor-depleted:tumor conjugates was not enhanced by LPS. Thus, LPS may enhance natural killer cell-like activity by increasing the binding of human lymphocytes to K562 tumors and by rearranging the population of binding cells to include more efficient killer cells. While the effects of LPS on binding appear independent of IFN, selective recruitment of more efficient killer cells could be through an IFN mechanism.

3H-thymidine incorporation was studied using peripheral blood mononuclear cells (PBMC) from 41 Egyptians with Schistosoma mansoni infection. The individuals were preselected to fall into 3 age-matched categories: asymptomatic with light and heavy infections and those with schistosomal hepatosplenomegaly. Seven uninfected individuals served as controls. PBMC from all groups were comparable in their responsiveness to phytohemagglutinin (PHA), streptokinase-streptodornase (SKSD), and the schistosome soluble egg antigen (SEA). However, DNA synthesis induced by soluble worm antigenic preparation (SWAP) differed significantly among these groups. The mean response to SWAP (delta cpm = experimental cpm minus control cpm +/- standard error) was markedly decreased in individuals with heavy infections (1,963 +/- 509) compared with those with light to moderate egg excretion (4,646 +/- 790; p less than 0.01). Moreover, 2 subgroups were discernible among patients with hepatosplenomegaly. Seven were unresponsive to SWAP (7659 +/- 231), whereas 13 had vigorous responses (14, 617 +/- 2263; p < 0.01). This is the first demonstration of an inverse relationship between specific immune responsiveness to adult worm antigens and intensity of infection in humans with schistosomiasis mansoni. The depressed lymphocyte reactivity in patients with heavy infection, whether cause or consequence of the parasite load, may perpetuate large worm burdens. Furthermore, the observations on patients with hepatosplenomegaly may reflect differing pathogenetic mechanisms.

Previous studies have shown that human alveolar macrophages produce less interleukin-1 (IL-1) in response to lipopolysaccharide (LPS) than do their precursors, blood monocytes. The purpose of this study was to compare the capacities of alveolar macrophages and blood monocytes to synthesize tumor necrosis factor (TNF) in response to LPS. Alveolar macrophages were obtained by bronchoalveolar lavage of healthy nonsmoking subjects, and blood monocytes were obtained by adherence of mononuclear cells to plastic. TNF activity was measured in supernatants and cell lysates as cytotoxicity to L929 fibroblasts (uptake of neutral red at 570 nm). TNF activity of alveolar macrophages stimulated at 10(6) cells/ml with LPS (10 micrograms/ml) for 16 h was 596 +/- 367, and of blood monocytes it was 60 +/- 84 U/ml (mean +/- SD, p less than 0.005). At no concentration of LPS and at no period of stimulation did alveolar macrophages express less TNF activity than did blood monocytes. In concurrent experiments, supernatants of LPS-stimulated alveolar macrophages contained less IL-1 activity than did blood monocytes. Lysates of both cell types contained less than 20% of total TNF activity. The TNF activity of LPS-stimulated alveolar macrophages was neutralized greater than 99% by monoclonal antibody to TNF-alpha; control monoclonal antibody OKT3 had no effect. Next, alveolar macrophages and blood monocytes were biosynthetically labeled with [3H]leucine during incubation with LPS; supernatants were immunoprecipitated with anti-TNF, and precipitates were electrophoresed on polyacrylamide gels. Autoradiographs indicated that immunoreactive TNF was produced by both blood monocytes and alveolar macrophages and that the relative molecular weights were identical (17,000).(ABSTRACT TRUNCATED AT 250 WORDS)

The immunobiology and mycobacterial species distribution of immunoabsorbent affinity chromatography-purified Mycobacterium tuberculosis antigen 5 have been studied. In delayed hypersensitivity skin tests, antigen 5 was nearly equipotent with tuberculin-purified protein derivative in sensitized guinea pigs. In vitro, antigen 5 was capable of stimulating the production of migration inhibitory factor by cultured lymphocytes from sensitized guinea pigs and humans. Antigen 5 stimulated thymidine incorporation by cultured guinea pig lymphocytes but did not stimulate thymidine incorporation by cultured human lymphocytes. Although erythrocytes were readily sensitized with antigen 5 for passive hemagglutination, their use did not offer any advantage over previous hemagglutination techniques for the serodiagnosis or evaluation of patients with tuberculosis. By immunoelectrophoresis and immunodiffusion, antigen 5 was readily identified in culture filtrates of 10 strains of M. tuberculosis and M. bovis but not in those of 30 strains of 12 other myobacterial species.

Splenic suppressor cell activity was evaluated in 10 patients with advanced hepatosplenic Schistosomiasis mansoni undergoing elective splenectomy. We used cell mixing experiments to assess the effect of mitomycin-C-treated spleen cells on antigen and mitogen-induced 3H-thymidine incorporation of responder cells. The suppressor to responder ratio was 1.0. Spleen cells from 7 of 10 patients caused at least 20% suppression of phytohemagglutinin-induced 3H-thymidine incorporation of one or more populations of responder cells (spleen cells, autologous and allogeneic peripheral blood mononuclear cells)Responses of peripheral blood mononuclear cells to streptokinase-streptodornase and schistosome soluble egg and worm antigen preparations also were inhibited by co-cultured spleen cells. An inverse correlation was apparent between the spleen cell response to PHA and the suppressor activity of that spleen cell population (r = -0.74, p less than 0.05). Cell purification procedures showed that the active suppressor splenic cell was non-adherent and rosetted neuraminidase-treated sheep erythrocytes. This splenic suppressor T lymphocyte may modulate splenic and peripheral blood lymphocyte responses in patients with hepatosplenic schistosomiasis.

A method is described for purification of large quantities of Giardia muris trophozoites from the small intestine of the mouse by using density layer centrifugation and nylon fiber columns. Centrifugation of trophozoites obtained from the small intestine on Metrizamide, specific gravity 1.10, followed by incubation on a nylon fiber column at 37 degrees C for 120 min, yielded up to 15 X 10(6) viable purified trophozoites per infected mouse.