The mediator of cellular immunity. 3. Lymphocyte traffic from the blood into the inflamed peritoneal cavity.

A substantial portion of the lymphocyte-like cells in induced peritoneal exudates derive from cells which enter the blood by way of the thoracic duct. The migrant cells have been identified as large and medium lymphocytes, but they may also include short-lived small lymphocytes derived from them. Small lymphocytes which have a potentially long circulating life-span are excluded from exudates, although cells of this type predominate in thoracic duct lymph. The results imply that many (perhaps all) of the small round cells in inflamed tissue are members of a line of rapidly proliferating lymphocytes. Specifically committed lymphocytes with precisely these properties are added to the blood of rats infected with Listeria monocytogenes. The localization of committed lymphocytes in inflammatory foci could be the crucial event which enables the host to focus his cellular defenses at sites of bacterial implantation.

Prostaglandins from human T suppressor/cytotoxic cells modulate natural killer antibacterial activity.

We have recently described potent antibacterial activity of purified human NK cells. Here we show that this function is regulated by T cytotoxic/suppressor CD8+ cells. Thus, coculture of NK and CD8+ cells for 3 h or longer times abrogated the expression of the NK antibacterial activity, and of two activation markers IL-2R and transferrin receptor (Tf-R). The suppressive activity was mediated by PGE2 as demonstrated by direct PGE2 determination in CD8+ cell free supernatants, and by inhibition of CD8+ cell suppression with indomethacin or piroxicam in vitro. We also found that resting T cytotoxic/suppressor cells purified by negative selection produce higher amounts of PGE2 than adherent cells like monocytes and macrophages, and that these concentration levels are in the range of concentrations known to suppress a significant number of in vitro immunologic functions.

The mediator of cellular immunity. I. The life-span and circulation dynamics of the immunologically committed lymphocyte.

Thoracic duct cells from rats which have survived an infection with Listeria monocytogenes can confer a high level of antimicrobial resistance upon normal recipients. The cells which confer protection appear in the thoracic duct during the 1st wk of the immunizing infection, at a time when newly formed lymphocytes are being added to the lymph in substantially increased numbers. The protective cells differ in at least two respects from the majority of small lymphocytes in central lymph: they have a rapid turnover rate and a short life-span in the circulation. Evidence was also obtained that lymphopoiesis affecting the long-lived small lymphocyte, which belongs to the recirculating pool, is not increased during an acute Listeria infection.

The mediator of cellular immunity. II. Migration of immunologically committed lymphocytes into inflammatory exudates.

Peritoneal exudates from rats which have survived an infection with L. monocytogenes can protect cyclophosphamide-treated recipients against a Listeria challenge. They are more effective in this respect than cells obtained from the spleen or thoracic duct lymph. Since exudate cells from normal rats and inocula prepared from the resident peritoneal cell populations of infected donors are unable to inhibit the challenge infection, the protective cells must belong to a class of lymphocytes that emerges from the blood in response to inflammation. It is significant therefore that thoracic duct lymphocytes formed during an acute Listeria infection can move into exudates induced by a variety of inflammatory stimuli. The affinity of newly formed lymphocytes for inflamed tissue points to a mechanism whereby the host marshalls its cellular defenses at sites of bacterial invasion. The tendency of short-lived lymphocytes to leave inflamed vessels might also explain their short-circulating life-span.

Antibacterial activity of human natural killer cells.

The in vitro effects of human NK cells on viability of Gram-negative and Gram-positive bacteria was investigated. PBLs depleted of glass-adherent cells showed a significant antibacterial activity that was increased as the concentration of NK cells became higher. Leu-11-enriched cells exhibited the most efficient bactericidal activity. Stimulation of NK cells with staphylococcal enterotoxin B for 16 h produced a significant increase in the antibacterial activity of all NK cells tested. The antibacterial activity of monocyte-depleted cells and Leu-11-enriched cells was also enhanced after culturing in vitro for 16-24 h without exogenous cytokines. Dependence of the antibacterial activity on the presence of serum in the culture medium was not found. Ultrastructural studies revealed close contact between NK cell membranes and bacteria, no evidence of phagocytosis, and extracellular bacterial ghosts, after incubation at 37 degrees C. Supernatants from purified NK cells exhibited potent bactericidal activity with kinetics and target specificity similar to that of effector cells. These results document the potent antibacterial activity of purified NK cells and suggest an extracellular mechanism of killing.

Disseminated macronodular cutaneous candidiasis in chronic alcoholism.

Disseminated candidiasis usually occurs in profoundly immunocompromised hosts. We described a case of disseminated macronodular cutaneous candidiasis in a man with no known risk for immunosuppression other than alcoholic liver disease and a second case of multiple macronodular cutaneous abscesses in an alcoholic man who had no evidence of systemic dissemination. One patient had testicular candidiasis, a previously unreported site of infection in disseminated candidiasis. Tests showed neutrophil and lymphocyte function to be normal; however, a marked defect in serum opsonization was demonstrated in one patient. It is postulated that chronic alcoholism with alcoholic liver disease resulted in impaired serum opsonization, which, in turn, predisposed these patients to candidal infection.

Discriminators between hantavirus-infected and -uninfected persons enrolled in a trial of intravenous ribavirin for presumptive hantavirus pulmonary syndrome.

To provide a potentially therapeutic intervention and to collect clinical and laboratory data during an outbreak of hantavirus pulmonary syndrome (HPS), 140 patients from the United States with suspected HPS were enrolled for investigational intravenous ribavirin treatment. HPS was subsequently laboratory confirmed in 30 persons and not confirmed in 105 persons with adequate specimens. Patients with HPS were significantly more likely than were hantavirus-negative patients to report myalgias from onset of symptoms through hospitalization, nausea at outpatient presentation, and diarrhea and nausea at the time of hospitalization; they were significantly less likely to report respiratory symptoms early in the illness. The groups did not differ with regard to time from the onset of illness to the point at which they sought care; time from onset, hospitalization, or enrollment to death was significantly shorter for patients with HPS. At the time of hospitalization, patients with HPS more commonly had myelocytes, metamyelocytes, or promyelocytes on a peripheral blood smear, and significantly more of them had thrombocytopenia, hemoconcentration, and hypocapnia. Patterns of clinical symptoms, the pace of clinical evolution, and specific clinical laboratory parameters discriminated between these 2 groups.

Cellular immune competence and diarrheal morbidity in malnourished Bangladeshi children: a prospective field study.

A year-long prospective study of 152 Bangladeshi children with mild to moderate protein-calorie malnutrition related nutritional status and cellular immune defects to morbidity due to diarrheal, respiratory, and febrile diseases. In children older than 36 mo, wasting correlated with skin test anergy to three recall antigens and with inability to initiate hypersensitivity to dinitrochlorobenzene. In this older age group, anergy was associated with a 58% increased attack rate and an 83% increased duration of diarrheal diseases but not with febrile or respiratory infections. In stepwise regression analysis, this anergy effect was independent of the small negative impact of poorer nutritional status on morbidity. Ninety-three percent of diarrheal illnesses lasting at least 14 d were among anergic children. Cellular immune incompetence, indicated by anergy of unknown etiology, is associated with increased diarrheal morbidity and may promote the vicious cycle of repeated infections and deteriorating nutritional status.

PIP: A year long prospective study of 152 Bangladeshi children with mild to moderate protein-calorie malnutrition related nutritional status and cellular immune defects to morbidity due to diarrheal, respiratory, and febrile diseases. In children older than 36 months, wasting correlated with skin test anergy to 3 recall antigens and with inability to initiate hypersensitivity to dinitrochlorobenzene. In this older age group, anergy was associated with a 58% increased attack rate and an 83% increased duration of diarrheal diseases but not with febrile or respiratory infections. In stepwise regression analysis, this anergy effect was independent of small negative impact of poorer nutritional status on morbidity. 93% of diarrheal illnesses lasting at least 14 days were among anergic children. Cellular immune incompetence, indicated by anergy of unknown etiology, is associated with increased diarrheal morbidity and may promote the vicious cycle of repeated infections and deteriorating nutritional status.

Anthropometric, metabolic, and immunological effects of recombinant human growth hormone in AIDS and AIDS-related complex.

Metabolic and anthropometric changes induced by "pharmacological" versus "physiological" doses (5.0 vs. 2.5 mg, every other day) of recombinant human growth hormone (rhGH) were compared in 10 human immunodeficiency virus-positive patients with AIDS or AIDS-related complex. Five patients were randomly assigned to each treatment schedule in a 3-month prospective, double-blind clinical trial. Three of the 10 patients, none taking zidovudine and all with low initial CD4 counts, were withdrawn during the study due to acute opportunistic infections. During treatment, insulin-like growth factor-1 (IGF-1) levels increased significantly (p < 0.05) in the pharmacological hGH treatment group, whereas no significant change was observed in IGF-1 in the physiological dose rhGH group. In the pharmacological hGH treatment group, weight loss preceding the study was reversed (p < 0.05) in each of the four patients who completed the study. This weight gain was associated with increases (p < 0.05) in lean body mass and total body water, with concomitant decreases in fat mass (p < 0.05) and urinary nitrogen excretion. Muscle power and endurance, as assessed by standardized omnikinetic dynamometry, also improved. All four patients lost weight again (p < 0.05) 6 weeks after completion of the study and termination of rhGH treatment. Minor positive changes in body composition were also observed in the physiologic-dose hGH group. The pharmacological dose of hGH was associated with minor increments (p < 0.05) in fasting plasma glucose, insulin, and C-peptide concentrations, which were of negligible clinical significance.(ABSTRACT TRUNCATED AT 250 WORDS)

Intravenous ribavirin for hantavirus pulmonary syndrome: safety and tolerance during 1 year of open-label experience. Ribavirin Study Group.

Intravenous ribavirin was provided non-selectively for investigational open-label use among persons with suspected hantavirus pulmonary syndrome (HPS) in the United States between 4 June 1993 and 1 September 1994. Therapy was initiated prior to laboratory confirmation of hantavirus infection because most deaths from HPS occur within 48 h of hospitalization. Thirty patients with confirmed HPS, 105 patients without HPS and 5 patients without adequate diagnostic testing for HPS were enrolled. This observational study arguably provides the most complete information available on ribavirin-associated adverse effects. Although ribavirin was generally well tolerated, 71% of recipients became anaemic and 19% underwent transfusion. An apparent excess of hyperamylasaemia/pancreatitis was either therapy-associated or due to enrollment bias. The 30 enrolled HPS patients had a case-fatality rate of 47% (14/30). It is not possible to assess efficacy with this study design. However, comparison of survival curves for the 30 enrolled HPS patients and 34 patients who developed HPS during the same time period but were not enrolled did not suggest an appreciable drug effect. A randomized, placebo-controlled trial that enrolls patients during the prodrome phase would be necessary to assess the efficacy and further define the safety of intravenous ribavirin for HPS.

The maximum conjugate frequency (alpha max) characterizes killer cell populations.

A quantitative procedure to characterize NK cell populations based on the dependence of the frequency of conjugation (alpha) on the effector-to-target ratio (R) is shown. To this end, a detailed study of the influence exerted by: (a) the value of R; (b) the number of effector and target cells (N, T); and (c) the source (donor) and enrichment of the effector cell population on the frequency of conjugation between NK effector and K562 target cells has been performed. This has demonstrated that for a given value of R large differences in the values of alpha can be obtained for different donors and/or N values. Hence, the usual practice of reporting the frequency of conjugation at a given value of R cannot be used as a valid criterion for comparison, and this could explain the differences in the alpha values reported in the literature for the same effector-target system. Moreover, the frequency of conjugation depends on the enrichment of the effector cell populations, although it has been shown that in all cases a plot of 1/alpha vs. R for N = constant is always linear with intercept 1/alpha max.alpha max represents the maximum frequency of conjugation for an effector-target system and remains constant for all values of R and N, and is also independent on the donor of the cell source. These characteristics make that the values of alpha max can be used as an easy criterion to determine with accuracy conjugate frequencies in an effector-target system, and could also be applied to characterize the activation or inhibition of effector cell populations by monoclonal antibodies or other agents. This criterion was applied to characterize the enrichment of NK cell populations and so, a value of alpha max = 58 +/- 3% has been obtained when highly purified (greater than or equal to 99%) NK effector cells obtained by panning with the monoclonal antibodies Leu-2, Leu-3 and Leu-4 are used. However, the corresponding value for MDC (14% NK cells) was lowered to 26 +/- 1%.

Alterations in lymphocyte cell surface markers during various human infections.

Peripheral blood lymphocyte cell surface markers were studied in 146 patients with various forms of acute infection using B cell identification with antisurface immunoglobulin and T cell subset enumeration with hybridoma T cell subpopulation reagents. Significant depression was recorded in total numbers of T cells and T cell helper-inducer and suppressor-cytotoxic subsets in pneumonia, acute pyelonephritis, and severe generalized sepsis. In addition, proportions of T cells being the OKT4 helper-inducer phenotype were reduced only in patients over the age of 60 with pneumonia or sepsis. Patients with severe infection frequently had multiple T cell phenotypic surface marker abnormalities. In some instances, when depressions of total T cell numbers as well as respective helper-inducer or suppressor-cytotoxic T cells were noted in the face of generalized sepsis, lack of improvement in these abnormalities during the course of treatment was associated with rapid clinical deterioration and death. On the contrary, in patients with a successful response to appropriate therapy, initial depressions of total T cell numbers and subsets improved progressively with clinical resolution of sepsis and illness.

Hantavirus pulmonary syndrome in the United States: a pathological description of a disease caused by a new agent.

An outbreak of an acute respiratory disease in the southwestern United States has led to the recognition of a new hantaviral illness. This report describes a unique spectrum of antemortem and postmortem pathological findings seen in a case series of nine surviving patients and 13 who died. Clinical, laboratory, and autopsy findings were derived from a consecutive series of individuals confirmed to have hantavirus pulmonary syndrome. Laboratory studies included chemical, hematological, and bone marrow analyses as well as flow cytometric and immunohistochemical phenotyping. Autopsy tissues were examined by routine histological stains, immunohistochemical methods, and transmission electron microscopy. The lung is the primary target organ in this illness. Pulmonary abnormalities include pleural effusions, alveolar edema and fibrin, and an interstitial mononuclear cell infiltrate. Large immunoblast type cells are seen in the lungs, blood, bone marrow, lymph nodes, liver, and spleen. A tetrad of hematological findings includes left-shifted neutrophilic leukocytosis, thrombocytopenia, hemoconcentration in severe cases, and circulating immunoblasts. In contrast to previously described nephropathic hantaviral syndromes, hantavirus pulmonary syndrome is characterized by a unique constellation of pulmonary, hematological, and reticuloendothelial pathological findings. The pulmonary findings are distinguishable from fatal adult respiratory distress syndrome. The data suggest a capillary leak syndrome restricted to the pulmonary circulation. Likewise, the hematological picture is unique and may be valuable in the rapid identification of cases for further diagnostic studies.

Renal histopathology in the hemolytic-uremic syndrome following shigellosis.

The hemolytic-uremic syndrome (HUS) following dysentery caused by S. dysenteriae Type 1, characterized by microangiopathic hemolytic anemia and acute renal insufficiency, is clinically similar but not identical to the idiopathic HUS. We studied renal necropsy specimens of nine children who died of HUS following shigellosis by light and immunofluorescent microscopy and compared them to 12 controls: six cases with severe shigellosis without HUS, and six with pneumonia or sepsis. Eight of nine HUS cases showed cortical necrosis, extensive glomerular thrombosis or arterial thrombosis. Cases without HUS showed only scattered glomerular fibrin thrombin and widening of the mesangium. Among seven HUS cases studied by immunofluorescent microscopy, three demonstrated deposition of glomerular IgM and complement (C3) and one of the three had IgG and IgA as well; four cases had neither immunoglobulin or complement deposits. Among nine controls, two demonstrated IgM and three IgG, but none had C3. Both HUS and non-HUS cases had fibrin deposition. In the three HUS cases studied by electron microscopy intracapillary material (fibrin and platelets) was seen in all three, and sparse electron-dense deposits in mesangial matrix in one. The data indicate that the renal histopathology in the HUS following shigellosis consistently presents as a severe thrombotic microangiopathy, but lacks the characteristic endothelial and mesangial lesions of idiopathic HUS. The infrequent demonstration of glomerular immunoglobulin deposition fails to support an immunoglobulin-mediated pathogenesis.

Mortality among primary and secondary cases of measles in Bangladesh.

Data were reviewed from an intensive 1975-1976 survey in two Bangladeshi villages that experienced a high incidence of measles. Mortality among secondary cases (four of 50, 8.0%) was significantly higher than that among primary cases (six of 290, 2.1%). In every case in which there was a death in a household with more than one case, it was the youngest patient who died. All children with secondary cases who died had a pre-illness weight-for-height status above the population mean. Measles mortality in Bangladesh appears to be determined by three factors: age, superinfections, and having a secondary case. The last two factors may be due to increased intrafamilial exposure to both the measles virus and the superinfecting pathogens.

Parenteral immunization causes antigen-specific cell-mediated suppression of an intestinal IgA response.

Rats immunized s.c. with cholera toxin (CT) or toxoid (CTd) show antigen-specific suppression of the jejunal IgA anti-CT response to subsequent enteric doses of CT. We determined whether this effect was partly cell-mediated and studied the suppressor cell response involved. Spleen cells from s.c.-immunized rats suppressed the jejunal anti-CT response in adoptive recipients when cell transfer was at, or 4 days before, intraduodenal priming with CT. Transferred suppression was antigen-specific, and the suppressor cells were nylon wool-nonadherent. Increasing the s.c. dose of CT from 0.1 to 40 micrograms, and the interval between immunization and cell harvest from 2 to 16 wk, each increased the suppressive effect of a constant spleen cell inoculum. After s.c. immunization, suppressor cells were present in the spleen within 1 to 2 wk, among TDL within 4 to 8 wk, and in Peyer's patches and thymus within 8 to 16 wk; this sequence suggested they arose in the spleen and later migrated to mucosae and the thymus. Prior splenectomy did not alter the suppressive effect of s.c. CT, however, nor did it prevent suppressor cell appearance among TDL, indicating that suppressor cells also arose from nonsplenic sites. Transferred suppressor cells acted by interfering with the development of specific immunologic memory within Peyer's patches during enteric priming; transfer of suppressor cells at the time of enteric boosting had no effect upon the secondary mucosal anti-CT response. We conclude that the suppressive effect of s.c. immunization on a specific mucosal IgA response is due largely to the action of systemically derived suppressor cells upon the primary mucosal immune response within Peyer's patches. This sequence resembles the mirror image of oral tolerance, which involves the suppression of systemic IgG and IgM responses by suppressor cells that arise in Peyer's patches and migrate to the spleen after antigen feeding.

Priming and suppression of the intestinal immune response to cholera toxoid/toxin by parenteral toxoid in rats.

Parenteral immunization of rats with cholera toxoid had both priming and suppressive effects upon the antitoxin response in jejunal lamina propria to locally applied toxoid/toxin. Priming was detected when parenteral toxoid was given i.p. but not i.v. or s.c., was enhanced by Freund's adjuvant, and appeared to reflect enhanced encounter of i.p. antigen with IgA-committed lymphocytes in extra-intestinal mucosa-associated lymphoid tissue. In contrast, suppression followed parenteral toxoid given i.p., i.v., or s.c.; suppression was antigen specific and lasted at least 16 weeks. Parenteral toxoid suppressed both primary and secondary types of mucosal antitoxin responses, ultimately preventing the generation of antitoxin-containing immunoblasts from Peyer's patches. Since suppression followed parenteral immunization by routes that did not provoke mucosal priming, it was, at least in those instances, not simply a regulatory consequence of mucosal priming. These results support the notion that priming and suppression of a specific mucosal immune response are independent effects of parenteral immunization that are probably determined by the distribution of antigen to mucosa-associated and systemic lymphoid tissue, respectively.

Cellular immunity in Q fever: specific lymphocyte unresponsiveness in Q fever endocarditis.

Human infection with the rickettsia Coxiella burnetii presents as acute influenza-like primary Q fever, subacute granulomatous hepatitis, or chronic endocarditis with hepatitis. To investigate whether persistent infection is associated with a possible immunologic defect, we tested lymphocyte proliferation specific for Coxiella in vitro in peripheral blood mononuclear cells from patients and controls. All four patients with endocarditis had profound lymphocyte unresponsiveness to Coxiella antigens with normal proliferation to control antigens. Hepatitis and primary Q fever were associated with vigorous responses in vitro to Coxiella antigens. Suppression of lymphocyte unresponsiveness was in part mediated by an antigen-nonspecific, glass-adherent cell. We hypothesize that specific T cell unresponsiveness is an important factor in persistent infection with C. burnetii and offer in vitro lymphocyte stimulation as a more specific diagnostic test to distinguish cases of endocarditis among those with chronic hepatitis due to Q fever.

Cellular immunity in Q fever: modulation of responsiveness by a suppressor T cell-monocyte circuit.

Human infection with the rickettsia Coxiella burnetii presents as an acute flulike primary Q fever, as a subacute granulomatous hepatitis, or, rarely, as chronic endocarditis. We have previously described lymphocyte unresponsiveness to Coxiella antigen in patients with Q fever endocarditis. This unresponsiveness was antigen specific and was mediated in part by adherent suppressor cells. In this report we show that the adherent suppressor cells work via prostaglandin E2 (PGE2)4 production. Addition of the cyclooxygenase inhibitor indomethacin to cultures of PBMC from patients with endocarditis or chronic laboratory exposure resulted in consistent increases in Coxiella-specific lymphocyte proliferation. The degree of increase in proliferation induced by indomethacin correlated strongly with the amount of PGE2 produced in a 4-hr culture stimulated by Coxiella antigen, but it also correlated with the sensitivity to inhibition of mitogenesis by PGE2. The suppressor mechanism was antigen nonspecific, because induction of suppression in vitro by Coxiella antigen also suppressed Candida-induced proliferation when both antigens were present in the same culture. Addition of indomethacin to these antigen cocultures totally reversed the Coxiella-induced suppression, confirming the evidence above that the nonspecific effector mechanism of suppression was prostaglandin (PG)-mediated. Elicitation of suppression, however, was antigen specific and involved a T cell-monocyte suppressor circuit. Supernatants from Coxiella-stimulated immune T cells and from the suppressor subset (OKT8+-enriched) of those T cells, but not unstimulated immune cells, induced augmented PGE2 production by unrelated nonimmune PBMC. We conclude that the lymphocyte unresponsiveness characterizing patients with Q fever endocarditis is modulated in part by an antigen-specific T suppressor cell which secretes a lymphokine to stimulate PGE2 production by adherent cells.