Increase and decrease of delayed cutaneous reactions obtained by hypnotic suggestions during sensitization Studies on dinitrochlorobenzene and diphenylcyclopropenone

Cutaneous reactivity to challenge with dinitrochlorobenzene (DNCB) and diphenylcyclopropenone (DCP) was studied in 16 volunteers following hypnotic suggestions to increase and decrease response during sensitization. The immunoreactivity to DNCB and DCP was modulated by direct suggestions and guided imagery under hypnosis. The volunteers were highly susceptible subjects selected by means of the Harvard Group Scale of Hypnotic Susceptibility. Form A. Measurement of skin reactions to the challenge I month after sensitization was performed double blindly. Results showed a significant ( P <0.01) difference in visually scored reactions to DCP and DNCB between the group instructed to increase reaction to DCP and decrease reaction to DNCB and the group given the opposite instructions. A non-significant difference ( P = 0.055) in skin thickness measured by ultrasound was found between the two groups. The study supports previous reports of experimental modulation of immunoreactivity and indicates that the specific immunnnological processes involved in the development of allergic reactions may be susceptible to psychological factors.     

Effect of locally administered heparins on delayed-type hypersensitivity reactions

Inflammatory reactions involved in delayed-type hypersensitivity (DTH) are associated with extravascular coagulation and fibrin deposition. Heparin and other anticoagulants administered systemically inhibit DTH reactions but the direct effect of intradermally injected heparin on the development of DTH skin responses has not been reported. The effects of heparin on the DTH reaction elicited by ovalbumin (OVA) in guinea pigs 1-3 weeks after sensitization were examined. Unfractionated heparin, low affinity heparin (LAH; non-anticoagulant) and high affinity heparin (HAH; anticoagulant) were injected together with suboptimal amounts of OVA. Heparin and LAH enhanced skin induration, LAH (0.5 micrograms) by an average of 50% above that due to OVA alone at 24 h (p less than 0.01). In contrast, HAH (0.5 micrograms) significantly reduced skin induration at 24 h. Heparin and LAH also significantly increased cellular infiltration with LAH having the greater effect. At 4 h the infiltrate consisted mainly of neutrophils whereas at 24 h mononuclear cells predominated. Fibrin deposition, assessed both by immunohistology and quantitation of radioactive fibrin extracted from skin test sites, was increased by 30% when OVA was tested in the presence of LAH. Mast cell heparin released locally at sites of DTH has the potential to modulate these reactions in either a pro- or anti-inflammatory manner. This study is the first to demonstrate differences in the capacities of LAH and HAH to modulate cell-mediated inflammation.     

Effect of hydrocortisone, cyclophosphamide, azathioprine and methotrexate on cutaneous delayed and arthus hypersensitivity in the rat.

The effect of 4 immunosuppressive agents--hydrocortisone (HC), cyclophosphamide (CY), azathioprine (AZ) and methotrexate (MTX)--, on cutaneous delayed-type hypersensitivity (DTH) and Arthus reactions to the intradermal injection of ovalbumin (OA) in rats sensitized to OA in Freund's complete adjuvant (FCA) was studied. Multiple doses (daily for 4 days) were given either early, beginning on the day of sensitization, or late, beginning 9 days after sensitization. Single doses were given on the day of challenge with OA. All late multiple doses of drugs except HC depressed the DTH at 24 h in the following order of decreasing magnitude: MTX, CY, AZ. The DTH at 24 h was depressed by early multiple doses of MTX at all doses, by CY at all but the lowest dose, and by AZ at the intermediate dose; HC had no effect. When the drugs were given as single late doses, only CY at the lowest dose and MTX at the higher doses effectively depressed the DTH at 24 h. Increased Arthus reactions occurred after early and late multiple doses of HC and after a late single dose of CY at the highest dose. After late multiple doses the Arthus reaction was unaffected by either CY or MTX but was depressed by all doses of AZ. HC administered as 3 injections around the time of challenge markedly depressed the delayed and Arthus reactions. These results show that each of the 4 immunosuppressive drugs could depress DTH and Arthus reaction to OA, but the degree of depression varied with the time of drug administration relative to sensitization and challenge, and the dose of drug used. Histologic examination of skin test sites showed that an apparently negative reaction did not necessarily imply total absence of a cellular inflammatory response.     

Modulation of Type I immediate and Type IV delayed immunoreactivity using direct suggestion and guided imagery during hypnosis

Cutaneous reactivity against histamine skin prick test (Type I) and purified tuberculin protein derivative (Mantoux reaction, Type IV) was studied in eight volunteers under hypnosis. Types I and IV immunoreactivity were modulated by direct suggestion (Type I) and guided imagery (Type IV). The volunteers were highly susceptible subjects, selected by means of the Harvard Group Scale of Hypnotic Susceptibility, Form A. When the volunteers underwent hypnotic suggestion to decrease the cutaneous reaction to histamine prick test, a significant (P less than 0.02) reduction of the flare reaction (area of erythema) was observed compared with control histamine skin prick tests. The wheal reaction did not respond to hypnotic suggestion. Neither wheal nor flare reaction could be increased in size by hypnotic suggestion compared with control histamine skin prick tests. A hypnotic suggestion of increasing the Type IV reaction on one arm and decreasing the reaction on the other revealed a significant difference in both erythema size (P less than 0.02) and palpable induration (P less than 0.01). In two cases the reactions were monitored by laser doppler blood flowmetry and skin thickness measurement by ultrasound. The difference between the suggested increased and decreased reaction was 19% for the laser doppler bloodflow (in favor of the augmented side), and 44% for the dermal infiltrate thickness. This study objectively supports the numerous uncontrolled case reports of modulation of immunoreactivity in allergic diseases involving both Type I and Type IV skin reactions following hypnotic suggestions.     

Langerhans' cells in the murine oral mucosa in the inductive phase of delayed type hypersensitivity with 1-chloro-2, 4-dinitrobenzene

We created a murine model of delayed-type hypersensitivity (DTH) to 1-chloro-2, 4-dinitrobenzene (DNCB). Using this murine model, we compared oral mucosal sensitization and skin sensitization for the difference in reaction during the elicitation phase. Evaluation of sensitizability, using the mouse ear swelling test (MEST) after oral mucosal or skin sensitization, showed that the ear swelling response peaked 24 h after challenge. The optimal induction concentration was 1.0% in both oral mucosal and skin sensitization, resulting in a positive reaction rate of 100%. However, the ear swelling response 24 h after challenge with the optimal concentration of DNCB (1.0%) was significantly lower in oral mucosal than in skin sensitization. We compared the oral mucosal and skin sensitization sites for the number of Langerhans' cells (LC) and the antigen-presenting capability in the induction phase. The numbers of F4/80+ major histocompatibility complex (MHC) class II+ LC before induction did not differ significantly between the oral mucosa and the skin. After induction, F4/80+ MHC class II+ LC increased in number, but the increase was significantly smaller in the oral mucosa than in the skin. MEST on anti-CD86 antibody-administered mice showed that ear swelling was similarly suppressed after oral mucosal or skin sensitization. In murine models of DTH after oral mucosal sensitization, the number of F4/80+CD86+ LC increased after induction, but the increase was significantly smaller than that in murine models of DTH after skin sensitization. This study showed that, in murine models of DTH, oral mucosal sensitization elicited a weaker reaction than skin sensitization. This was presumably because oral mucosal sensitization induced fewer LC, resulting in lower antigen-presenting capability.     

Changes in electromyographically recorded human monosynaptic reflex in relation to hypnotic susceptibility and hypnosis

The aim of the present experiment was to study how hypnotic susceptibility and hypnosis affect motoneuron excitability. In a first trial, human subjects were selected according to their hypnotic susceptibility. In a second trial, the Hoffmann (H) reflex amplitude of the soleus muscle was studied in 3 groups: (1) highly susceptible subjects during hypnosis with standardized suggestions of simple relaxation, anesthesia, analgesia and paralysis (group I), (2) highly susceptible subjects (group II), and (3) non-susceptible subjects (group III) during long-lasting control conditions. Surface Ag/AgCl electrodes were used to stimulate the posterior tibial nerve using a constant current stimulator and to record the soleus EMG. Analysis of variance was performed on the data. The linear correlation coefficient within groups was evaluated. The H reflex amplitude decreased significantly during the recording session in groups I and II and there was no change in group III. In group I the effect of different suggestions could not be distinguished from the effect of hypnotic relaxation. The decrements in H amplitude did not differ between groups I and II, suggesting that the effect was related to personality traits rather than hypnotic induction.     

Establishment and comparison of delayed-type hypersensitivity models in the B6C3F1 mouse

The objective of these studies was to establish and compare delayed-type hypersensitivity (DTH) models, using keyhole limpet hemocyanin (KLH), sheep red blood cells (SRBC), and Candida albicans as sensitizing antigens, for their capability to assess a DTH response (utilizing footpad swelling as the endpoint) with minimal confounding factors resulting from antigen-specific antibody (Ab) production. The key elements of the DTH are the sensitization dose, time interval between sensitization and challenge [i.e. the challenge interval (CI)], and the challenge dose. Models were established by first determining the challenge dose, or the amount of antigen that produced no greater footpad swelling 24-h post-injection than the trauma induced by injection of physiological saline. Time-course studies determined the CI that produced a peak response for each antigen. Dose-response sensitization studies were conducted to determine the optimum sensitization concentration (i.e. maximum footpad swelling with minimal impact by antigen-specific Ab production). Footpad swelling decreased dose-responsively with increasing KLH sensitization concentration and corresponded to a dose-responsive increase in KLH-specific Ab levels. In the SRBC model, footpad swelling decreased at the high dose (1?×?10⁹ SRBC/mouse), and a corresponding increase in SRBC-specific Ab was observed at this dose level. A dose-responsive increase in footpad swelling was observed in the C. albicans model up to 3?×?10⁷ organisms/mouse, while antigen-specific antibody levels were not different from background (unsensitized) levels following sensitization with any concentration of C. albicans (up to 1.2?×?10⁸ organisms/mouse, the highest concentration tested). Finally, each model was evaluated for its ability to detect immunosuppression following exposure to benzo[a]pyrene (B[a]P), with the C. albicans model demonstrating greater sensitivity than the other models. These results indicate that, of the three models examined here, the C. albicans DTH model may be the most appropriate model for evaluating effects on cell-mediated immunity when conducting immunotoxicological investigations.     

Cyclosporin A prevents suppression of delayed-type hypersensitivity in mice immunized with high-dose sheep erythrocytes.

When administered intraperitoneally to mice 2 days before immunization with a tolerogenic dose (10(9)) of sheep red blood cells (SRBC), cyclosporin A (CsA; 200 mg/kg) strikingly augmented 4-day delayed-type hypersensitivity (DTH) footpad reactions. These enhanced responses were similar in magnitude to those seen in animals sensitized with an immunogenic, low-dose (10(6)) SRBC. The stimulatory effect of CsA was observed over the dose range of 5-200 mg/kg and was obtained in animals given the drug in one injection, up to 7 days before sensitization. The augmentation of DTH was characterized by footpad swelling, intense mononuclear cell infiltration and increased deposition of 125I-fibrinogen within the challenge site. In addition, increased expression of procoagulant activity by spleen cells in response to antigen was observed. Cell transfer experiments showed that the CsA-enhanced DTH could be adoptively transferred to naive recipients. Additional transfers conducted at the time of antigen challenge suggested that, under the conditions described, CsA inhibited the action of a population of suppressor cells normally effective during DTH reactions.     

Long-lasting enhancement of the delayed-type hypersensitivity response to heterologous erythrocytes in mice after a single injection of cyclophosphamide.

Previous reports have indicated that cyclophosphamide (CY) treatment can enhance delayed-type hypersensitivity (DTH) reactions by abrogating suppressor T cell functions. Such findings have suggested that cells in the suppressor lineage may be particularly sensitive to this alkylating agent. The experiments reported here demonstrate that a single injection of CY before sensitization can induce a long-lasting state of enhanced DTH responsiveness to sheep red blood cells (SRBC) in mice. This enhancement required concurrent antigenic stimulation and appeared to be antigen-specific. Additionally, CY treatment of sensitized mice before the first antigenic challenge for DTH resulted in suppressed responses to that challenge, followed by enhanced DTH to subsequent challenge with the same antigen. The suppressed response was achieved with a lower dose of CY than the subsequent enhancement and also required concurrent antigenic stimulation. These results indicate that the effects of CY on both effector and suppressor mechanisms are critically dependent upon antigenic stimulation, and suggest that apparent suppressor sensitivity to CY may be a function of differential ability to recover from CY treatment in a context of antigenic stimulation.     

Studies on delayed-type hypersensitivity (DTH) reactions in the pleural cavity in mice: prolonged DTH reaction and its interruption by cyclophosphamide treatment

DTH reactions to sheep erythrocytes (SRBC) and purified protein derivative (PPD) antigens were produced in the pleural cavity in mice. The profiles of the DTH reactions with respect to time course and cellular exudate reactions differed greatly according to the strains of mice. In particular, HY mice that were established in our laboratory displayed prolonged DTH reactions, characterized by macrophage followed by lymphocyte reactions. HY X C3H F1 mice showed a similar tendency. On the other hand, strains such as C3H, BALB/c, DBA/2 and B6 mice showed short-lived and macrophage-predominant DTH reactions. BALB/c nu/nu mice showed no DTH reactions. Characteristic features of the prolonged DTH reactions in HY mice were transferred with sensitized T cells. However, DTH reactions in HY mice treated with cyclophosphamide (CY) terminated in a short period, and mainly consisted of macrophages and polymorphs, although they were greatly enhanced. Such profiles of the reactions could also be transferred with sensitized T cells from CY-treated and SRBC-sensitized mice. Spleen cells taken from CY-treated and SRBC-sensitized HY mice, when injected intravenously into SRBC-sensitized HY mice just prior to challenge, could not interrupt prolonged DTH reactions. These results thus indicated various phenotypes of the DTH reactions in terms of time course and exudate cellular component involved might be carried by the specific effector T cells in each phenotype of the DTH reactions and could be induced using strains of mice and CY.     

The pattern of human late-phase skin reactions to extracts of aeroallergens

The kinetics and dose response of cutaneous late phase reactions (LPR) (defined as greater than 5 mm induration 6 hours after intradermal challenge with allergen) were studied in 20 randomly selected subjects with atopic rhinitis. When subjects were challenged intradermally with 0.2 biologic unit (BU) of Dermatophagoides pteronyssinus or grass pollen, wheal-and-flare reactions were elicited without subsequent LPRs. With 30 BU, all subjects developed LPRs, whereas 1 and 10 BU provoked LPRs in 28% and 64%, respectively. No biphasic responses were detected. At all concentrations which progressed to form an LPR, a palpable skin reaction was continuously present and either remained constant or increased steadily in magnitude during 6 hours. Skin reactions of similar diameter provoked by histamine resolved fully within 2 hours. Thus, we confirm that the development of a macroscopic cutaneous LPR requires a higher concentration of allergen than the wheal-and-flare reaction. Together with our other findings, these results suggest that all untreated atopic individuals are capable of mounting an LPR if they are challenged with sufficient allergen. In contrast to the asthmatic response to inhaled allergen, the cutaneous wheal and LPR are not biphasic.     

The skin inflammatory response of the badger (Meles meles)

Twenty-five badgers, captured in an area where they had been implicated in outbreaks of bovine tuberculosis, received intradermal inoculations of control medium, 150 micrograms phytohaemagglutinin (PHA), 40 units streptokinase/10 units streptodornase (SK/SD), 200 micrograms purified protein derivative of Mycobacterium bovis (PPD), Freund's incomplete adjuvant (IFA), and Freund's complete adjuvant (CFA), each in 0.1 ml of inoculum. The reactions were assessed by skinfold thickness and skin histology 30 min--7 days after inoculation. Control medium caused slight cellular reaction, mostly polymorphonuclear leucocytes (PMNs), but no significant increase in skinfold thickness. SK/SD provoked no reaction. PHA stimulated a marked increase in skinfold thickness; the cellular reaction was predominantly PMNs, with some macrophages occurring after several days. IFA and CFA promoted a long-lasting increase in skinfold thickness, and a mixed histological picture of PMNs and macrophages; later in the response, especially to CFA, giant cells and some lymphocytes occurred. PPD stimulated a small increase in skinfold thickness with a timing (2-3 days) consistent with delayed hypersensitivity (DTH); there was, however, no erythema or palpable oedema or induration. The histology was an initial multifocal reaction of PMNs with a later phase of lymphocytes and macrophages with some granuloma formation. Other cell types (eosinophils, basophils) were seen in varying proportions in all reaction sites. M. bovis was isolated from four badgers; the cellular reaction to PPD was stronger than in uninfected animals, but other aspects of the skin response were unaffected. This study shows the capacity of badgers for strong inflammatory responses, and is the first report of a DTH response to PPD in this species.     

Delayed-Type Hypersensitivity in the Mouse

A simple reproducible footpad assay of delayed-type hypersensitivity (DTH) in CBA, C3H, and Bagg mice to Salmonella adelaide flagellin and its derivatives is described. DTH reactions were of delayed onset (12-24 hours), long duration (3-4 days), and characterized histologically by extensive infiltration of the hypodermis and muscle with mononuclear cells. Immediate (0-3 hours) and late (36-48 hours) Arthus reactions were also observed in certain instances but did not preclude detection of the 24-hour DTH reaction. Maximal DTH reactivity was induced by microgram doses of monomeric (MON) or polymerized (POL) flagellin in saline, 2-8 days after primary challenge. POL elicited greater DTH reactions than MON, presumably because of its larger size.     

Effect of rifampin and its cyclopentyl analogue, MDL 473, on the expression of delayed type hypersensitivity to oxazolone

The purpose of this study was to determine the effect of rifampin and its cyclopentyl analogue, MDL 473, on delayed type hypersensitivity (DTH) using a murine model. Neither compound has any significant effect on DTH (as measured by ear swelling) to oxazolone when administered i.p. to BALB/c mice at doses of 1, 10, 50 or 100 mg/kg beginning 3 days before oxazolone sensitization and continuing until hapten challenge 5 days later. In contrast, sex and age matched controls receiving 200 mg hydrocortisone/kg i.p. beginning on the day of oxazolone sensitization and continuing to hapten challenge demonstrate a significant (P less than 0.001) abrogation of DTH.     

Altered immune response (humoral and delayed-type hypersensitivity reactions) to sheep red blood cells in the course of experimental filarial infections (Litomosoides carinii,Brugia malayi,Acanthocheilonema viteae) ofMastomys natalensis

Litomosoides carinii-, Acanthocheilonema viteae- orBrugia malayi-infectedMastomys natalensis were sensitised against sheep red blood cells (SRBC) on various occasions after infection to determine the effect of filarial infections on the immune response to a non-filarial antigen. The phagocytic activity of the reticuloendothelial system (RES) was controlled in vivo by the elimination of⁵¹Cr-labelled SRBC. Antibody titres against SRBC (agglutinating and lytic antibodies) were similar to those of uninfected controls inL. carinii-orB. malayi-infectedMastomys sensitised during prepatency or early patency up to 90 days post infection (p.i.) but were reduced in animals sensitised during patency. A significant inverse correlation existed between anti-SRBC antibody titres and microfilaraemia levels. In contrast,A. viteae-infectedMastomys showed reduced humoral anti-SRBC responses at the end of prepatency, whereas the response tended towards normal with increasing parasitaemia. Delayed-type hypersensitivity (DTH) against SRBC was measured as footpad swelling after sensitisation by the s.c. or i.v. route and intraplantar challenge. DTH reactions were reduced during prepatency in all infections after s.c. sensitisation. During patency, 24-h reactions were similar to those of age-matched controls but the swelling persisted 24 or 48 h longer than in the latter. InA. viteae infections, even enhanced 24-h reactions were found during patency. Histological investigations did not reveal differences in the type of cell infiltrations between infected and control animals. After i.v. sensitisation with SRBC,L. carinii- andA. viteae-infected animals showed weaker DTH reactions than the controls, independent of the period after infection. In the case ofB. malayi infections, DTH reactions were similar to those of controls during early prepatency, whereas reduced DTH responses were observed later than 50 days p.i. As shown inL. carinii-infected animals, depressed DTH reactions after i.v. sensitisation did not depend on an altered expression phase but rather on an altered regulation during the inductive phase of the response: increases in the sensitising SRBC doses that caused decreasing DTH reactions in uninfected animals led to enhanced reactions in infected animals. Phagocytosis of i.v. injected⁵¹Cr-labelled SRBC was enhanced during prepatency inL. carinii infection and during patency in all infections.Dedicated to Prof. Dr. W. Peters on the occasion of his sixtieth birthdaySupported by a DAAD grant     

Quantitative relationships between sensitizing dose of DNCB and reactivity in normal subjects

We have developed quantitative methods which enable us to measure susceptibility to sensitization with dinitrochlorobenzene (DNBC) and the degree of responsiveness of groups, and to analyse factors affecting the afferent and efferent components of the response. Five groups of normal subjects (132 individuals) were sensitized with DNCB (1,000, 500, 250, 125 or 62.5 micrograms). One month later, each subject was challenged with 12.5, 6.25 and 3.125 micrograms of DNCB on standard patch test felts. After 48 h the reaction at each challenge site was graded clinically and measured as diameter of induration and increase in skinfold thickness. The proportion of subjects sensitized increased with sensitizing dose; 8% were sensitized by 62.5 and 100% were sensitized by 500 micrograms or more. The 50% sensitizing dose (ED50) was calculated as 116 micrograms. Increase in skinfold thickness proved the best method of assessing response and was linearly related to log challenge dose. There was also a linear relationship between degree of sensitivity and log sensitizing dose so that, on average, each time sensitizing dose was halved, the challenge dose required to produce the same response increased 1.5-fold. These methods can be used to measure sensitizability of a population, the degree of sensitivity and the expression of reactivity. The technique will allow quantitative study of factors altering the induction or expression of such reactivity in disease.     

Use of micrometers and calipers to measure various components of delayed-type hypersensitivity ear swelling reactions in mice

The choice of the type of instrument to measure delayed-type hypersensitivity (DTH) in mice, as assayed by ear swelling reactions, influences the experimental results. When a caliper that applies little pressure to the ears is employed, DTH reactions in ears of mice sensitized to picryl chloride show an early onset at 2 h after challenge, comparable swelling at 4 h and a slow rise to a 24 h classical peak response thereafter. In contrast, 3 different micrometers that apply more pressure to the ears reveal a biphasic pattern of ear swelling reactions in mice immunized and challenged with picryl chloride. The early component of DTH measured by these micrometers peaks 2 h after challenge. Thereafter the measured ear thickness declines, and the onset of the classical delayed reaction is detected at 12 h after ear challenge. Yet another instrument, that in contrast to the caliper and micrometers mentioned above, applies all the pressure to only a very restricted area of the ear, fails to detect an early sweeling reaction; the delayed reaction is first detected at 12 h after ear challenge and rises there after to a 24 h peak.The differences in outcome of the assays using the different instruments indicate that the early component or DTH reactions differs from the late component of DTH reactions in that the early swelling is easier to compress when pressure is applied by the instrument used for measurement. This is probably caused by the fact that the late reactions are due to a cellular infiltrate, whereas the early reactions are edematous in character, and are due to accumulation of plasma components.     

白细胞移动抑制因子(LMIF)释放的测定及条件性抑制LMIF的作用

目的选用与迟发过敏（ＤＴＨ）反应密切相关的白细胞移动抑制因子（ＬＭＩＦ）的体外测定方法，分析在条件性免疫抑制反应中ＬＭＩＦ活性的变化。方法ＬＭＩＦ测定是以间接毛细管方法结合分光光度计，测定游出细胞的吸光度（Ａ值）。在条件性反应训练和建立ＤＴＨ反应模型的第７天，取耳称重，同时取小鼠肠系膜淋巴结细胞，制备ＬＭＩＦ。结果ＬＭＩＦ在条件反应组的作用明显减弱（Ａ值升高），与不经过条件性训练的对照组相比，差异有非常显著意义（Ｐ＜０．０１，方差分析，ｎ＝７），但与非条件反应组相比没有差异，说明已形成了条件性抑制ＬＭＩＦ的反应。结论本工作建立了稳定的ＬＭＩＦ吸光度检测法，建立了环磷酰胺条件性抑制ＬＭＩＦ的模型。为深入分析条件性免疫抑制反应的血清中的介导物质提供了一个方便的体外检测手段     

Performance of antigens used in detecting delayed-type hypersensitivity in adolescents infected with the human immunodeficiency virus

We examined the performance of delayed-type hypersensitivity (DTH) antigens employing a new Candida albicans product in a human immunodeficiency virus (HIV)-infected and nonanergic adolescent population. Diameters of induration (in millimeters) for three intradermally applied antigens (C. albicans, tetanus toxoid, and mumps) were compared in a population of HIV-infected 12 to 18 year olds at study entry in a national multicenter study of HIV disease progression. CD4+ T-cell counts were measured in quality-controlled laboratories. The influence of past immunization, gender, and clinical status on antigen reactivity was evaluated with contingency table comparisons and relative risk estimation. Nearly one-half of the 123 eligible subjects were untreated, and almost three-quarters were early in HIV disease by clinical indicators. There was no statistically significant difference in reactivity by past immunization status. Candida antigen (CASTA; Greer Laboratories) evoked DTH response in a significantly higher number of males and females at every level of induration (largest P value, 0.049 for male comparisons; all P values, <0.001 for females) and in subjects with early and intermediate HIV disease at every level of induration (all P values, <0.0001) than either tetanus or mumps antigens. No two-antigen combination was as useful as all three antigens across either gender or clinical categories, although candida and tetanus was the most useful two-antigen combination at indurations of <3 mm. The superior performance of a new C. albicans antigen may extend the utility of DTH assessment in monitoring immune function.     

Ligation of CR1 (C3b receptor, CD35) on CD4+ T lymphocytes enhances viral replication in HIV-infected cells

The nature and phenotype of infiltrating cells in DTH-like reactions elicited in the murine oral mucosa have been examined by routine histological and immunohistochemical procedures. During the first few hours that followed buccal challenge with the contact sensitizer oxazolone, a discrete lymphocytic reaction was disclosed in the oral mucosa of animals previously sensitized at skin sites, but was absent in animals that had been sensitized at buccal sites. The early lymphocytic reaction in the oral mucosa of skin-sensitized animals preceded the emergence of CD11⁺ polymorphonuclear cells (PMN) which was most prominent 8 h after hapten challenge and invaded the whole thickness of the oral epithelium. The PMN rapidly disappeared by 24 h. In contrast, early PMN infiltration was virtually absent in specimens from animals similarly challenged but that had been sensitized at local buccal sites. Irrespective of site of initial sensitization, inflammatory reactions developed in the oral mucosa, being maximal by 24 h. At that stage, CD11⁺ macrophages were the predominant cell type. Both CD4 and CD8 T lymphocytes were scattered in both lamina propria and epithelium, and their numbers were raised throughout the time period studied (2–168 h). IL-2 receptor expression was maximal 16 h post-challenge, and was paralleled by increased DNA synthesis in CD4⁺ and CD8⁺ cells, as demonstrated by paired immunohistoautoradiography. Focal accumulations of mononuclear cells containing IL-2-producing cells were readily detected as early as 2–3 h following local challenge with hapten in animals primed at skin but not at buccal sites. Maximal IL-2 staining was detected at 24 h irrespective of initial sensitization site. Interferon-gamma-producing cells were detected at 8 h post-challenge and remained increased during the first 24 h. MHC class II expression was detected on few oral mucosa cells during the first 4 h following hapten challenge, being mainly confined to dendritic-like cells. Consistent with increased numbers of macrophages, MHC class II expression was most intense in specimens obtained 8–24 h after hapten challenge. Thereafter, MHC class II expression was still observed in specimens obtained as late as 72 h, but was essentially associated with patches of basal keratinocytes. Taken together, these observations support the notion that the murine oral mucosa can serve as the site of expression of locally or remotely induced DTH reactions, but also indicate that the site of initial sensitization can profoundly affect the cellular composition of inflammatory reactions subsequent to local buccal challenge.