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SARS CoV-2 virus has infected more than 200 million people worldwide and more than 4.4 million in Indonesia. The vaccination program has become one of the solutions launched by many countries globally, including Indonesia, to reduce the transmission rate of COVID-19. Various vaccination platforms are produced, such as inactivated, viral vector, mRNA, and protein subunit. The vaccination booster program with mRNA platform (Moderna) was launched by the Indonesian government to give better protection for health care workers, particularly from delta variant. In this case report, we discuss one of the typical side effects of Moderna vaccine, which is referred to as the COVID arm.

We have shown previously that collagen V (col(V)) autoimmunity is a consistent feature of atherosclerosis in human coronary artery disease and in the Apoe(-/-) mouse model. We have also shown sensitization of Apoe(-/-) mice with col(V) to markedly increase the atherosclerotic burden, providing evidence of a causative role for col(V) autoimmunity in atherosclerotic pathogenesis. Here we sought to determine whether induction of immune tolerance to col(V) might ameliorate atherosclerosis, providing further evidence for a causal role for col(V) autoimmunity in atherogenesis and providing insights into the potential for immunomodulatory therapeutic interventions. Mucosal inoculation successfully induced immune tolerance to col(V) with an accompanying reduction in plaque burden in Ldlr(-/-) mice on a high-cholesterol diet. The results therefore demonstrate that inoculation with col(V) can successfully ameliorate the atherosclerotic burden, suggesting novel approaches for therapeutic interventions. Surprisingly, tolerance and reduced atherosclerotic burden were both dependent on the recently described IL-35 and not on IL-10, the immunosuppressive cytokine usually studied in the context of induced tolerance and amelioration of atherosclerotic symptoms. In addition to the above, using recombinant protein fragments, we were able to localize two epitopes of the α1(V) chain involved in col(V) autoimmunity in atherosclerotic Ldlr(-/-) mice, suggesting future courses of experimentation for the characterization of such epitopes., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)

The formation of unstable, leaky neovessels underlies the pathogenesis of many chronic inflammatory diseases. Granzyme B (GZMB) is an immune-derived serine protease that accumulates in the extracellular matrix (ECM) during chronic inflammation and is capable of cleaving fibronectin (FN). Vascular endothelial growth factor (VEGF) is a potent vascular permeabilizing agent that is sequestered in the ECM through its interaction with FN. As GZMB levels are elevated in chronic inflammatory diseases that are associated with increased vascular permeability, the role of GZMB in the regulation of VEGF bioavailability and vascular permeability were assessed. GZMB was added to either VEGF bound to FN or VEGF bound to endothelial cell (EC)-derived ECM. Supernatants containing released VEGF were assessed to determine VEGF activity by treating EC and evaluating VEGF receptor-2 (VEGFR2) phosphorylation. GZMB released VEGF from both FN and from EC-derived matrix, whereas GZMB inhibition prevented FN cleavage and VEGF release. GZMB-mediated VEGF release resulted in significant phosphorylation of VEGFR2. The role of GZMB-mediated VEGF release in altering vascular permeability was also assessed in vivo using Miles/Evans blue permeability assay. GZMB induced a significant VEGF-dependent increase in vascular permeability in vivo that was reduced in the presence of an anti-VEGF-neutralizing antibody. Inflammatory-mediated vascular leakage was also assessed in GZMB-KO mice using a delayed-type hypersensitivity model. GZMB-KO mice exhibited reduced microvascular leakage compared with C57\B6 controls. GZMB increases vascular permeability in part through the proteolytic release of ECM-sequestered VEGF, leading to VEGFR2 activation and increased vascular permeability in vivo. These findings present a novel role for GZMB as a modulator of vascular response during chronic inflammation.

Background and Purpose: The intermediate-conductance Ca(2+)-activated K(+) channel (K(Ca)3.1) modulates the Ca(2+) response through the control of the membrane potential in the immune system. We investigated the role of K(Ca)3.1 on the pathogenesis of delayed-type hypersensitivity (DTH) in auricular lymph node (ALN) CD4(+) T-lymphocytes of oxazolone (Ox)-induced DTH model mice., Experimental Approach: The expression patterns of K(Ca)3.1 and its possible transcriptional regulators were compared among ALN T-lymphocytes of three groups [non-sensitized (Ox-/-), Ox-sensitized, but non-challenged (Ox+/-) and Ox-sensitized and -challenged (Ox+/+)] using real-time polymerase chain reaction, Western blotting and flow cytometry. KCa 3.1 activity was measured by whole-cell patch clamp and the voltage-sensitive dye imaging. The effects of K(Ca)3.1 blockade were examined by the administration of selective K(Ca)3.1 blockers., Key Results: Significant up-regulation of K(Ca)3.1a was observed in CD4(+) T-lymphocytes of Ox+/- and Ox+/+, without any evident changes in the expression of the dominant-negative form, K(Ca)3.1b. Negatively correlated with this, the repressor element-1 silencing transcription factor (REST) was significantly down-regulated. Pharmacological blockade of K(Ca)3.1 resulted in an accumulation of the CD4(+) T-lymphocytes of Ox+/+ at the G0/G1 phase of the cell cycle, and also significantly recovered not only the pathogenesis of DTH, but also the changes in the K(Ca)3.1 expression and activity in the CD4(+) T-lymphocytes of Ox+/- and Ox+/+., Conclusions and Implications: The up-regulation of K(Ca)3.1a in conjunction with the down-regulation of REST may be involved in CD4(+) T-lymphocyte proliferation in the ALNs of DTH model mice; and K(Ca)3.1 may be an important target for therapeutic intervention in allergy diseases such as DTH., (© 2013 The British Pharmacological Society.)

Aim: to investigate the effects cannabidiol (CBD) on delayed-type hypersensitivity (DTH) reactions and antigen-induced T-cell cytokine expression., Methods: DTH was induced by subcutaneous ovalbumin (OVA) challenge to the footpads of mice sensitized with OVA. Inflammatory reactions were measured by footpad swelling and histological analysis. Antigen-induced cytokine expression by OVA-primed splenocytes was measured using ELISA and RT-PCR., Results: CBD (1-10 mg/kg) administration, in a dose-dependent fashion, significantly attenuated inflammatory reactions associated with DTH in the footpads of mice sensitized and challenged with OVA. Histological examination revealed that CBD suppressed the infiltration of T cells and macrophages, and the expression of interferon (IFN)-γ and tumor necrosis factor-α, two pro-inflammatory cytokines implicated in DTH in the inflammatory site. In contrast, the expression of interleukin (IL)-10 in the footpads was enhanced by CBD administration. In addition, CBD at concentrations devoid of cytotoxic effects (1-4 micromol/L) attenuated OVA-induced IFN-γ production by OVA-primed splenocytes, whereas IL-4 was unaffected., Conclusion: CBD curbs DTH reactions via suppressing the infiltration and functional activity of T cells and macrophages in the inflammatory site, suggesting a therapeutic potential for CBD for the treatment of type IV hypersensitivity.

A 16-year-old Bangladeshi girl presented with a 9-day history of an extensive pruritic, erythematous, papulovesicular skin eruption to both forearms. Appearance was 5 days following application of a home-made henna preparation. Examination revealed ulceration and scabbing along the whole henna pattern and early keloid formation. A diagnosis of type IV delayed hypersensitivity reaction superimposed by infection was initially made. As in this case, home-made henna preparations commonly combine commercial henna with black hair dye, paraphenylenediamine (PPD). PPD, widely known as 'black henna', darkens the pigment and precipitates the drying process. PPD is a potent contact allergen associated with a high incidence of hypersensitivity reactions. Despite treatment the patient was left with extensive keloid scarring in the pattern of the henna tattoo.

The allergy-preventive activity of a 35% EtOH extract (IT) of flowers of Impatiens textori MIQ. was demonstrated in a continuing search for allergy-preventive substances from natural sources. The evaluation of its activity used an in vivo assay method for monitoring the blood flow decrease in the tail vein microcirculation of mice subjected to sensitization with hen-egg white lysozyme. Among the principal compounds in IT, apigenin (1), luteolin (3), and luteolin 7-glucoside (4) showed significant allergy-preventive effects.

Background and Purpose: Our aim was to examine the effect of demethylnobiletin on various experimental models of delayed-type hypersensitivity (DTH) reactions and to determine its influence on the mediators and enzymes involved in these reactions., Experimental Approach: DTH was induced in mice by oxazolone, dinitrofluorobenzene (DNFB) and sheep red blood cells (SRBC). The effect of demethylnobiletin on the ensuing DTH was studied, especially in relation to oedema formation, cell infiltration and tissue damage. Its activity on different mediators implicated in DTH reactions was also determined and its effect on nitric oxide synthase (NOS)-2 analysed. Finally, its influence on T lymphocyte proliferation, apoptosis and caspase 3 activity was tested., Key Results: DTH reactions were all reduced by demethylnobiletin. The experimental results suggest that the compound may act by reducing cell infiltration and by suppressing mediators such as interleukin-2 (IC50=1.63 microM), interleukin-4 (IC50=2.76 microM), tumour necrosis factor-alpha (IC50=0.66 microM), interferon-gamma (IC50=1.35 microM), and interleukin-1 beta (46% at 2.5 microM) and by concomitantly increasing the production of the anti-inflammatory cytokine, interleukin-10. In addition, while demethylnobiletin affected nitric oxide production, it did not modify NOS-2 expression. Finally, demethylnobiletin inhibited proliferation of T cells and induced their apoptosis., Conclusions and Implications: Demethylnobiletin decreased DTH reactions induced by various agents. This finding, along with the fact that the compound has a low toxicity and exhibits several other interesting properties, could pave the way for other structurally related citroflavonoids to be used as pharmacological agents in complementary therapies.

Individuals of many nontropical rodent species display reproductive, immunological, and somatic responses to day length. In general, short day (SD) lengths inhibit reproduction and enhance immune function in the laboratory when all other conditions are held constant. Most studies to date have focused on seasonal variation in immune function in adulthood. However, perinatal photoperiods also communicate critical day length information and serve to establish a developmental trajectory appropriate for the time of year. Nontropical rodents born early in the breeding season undergo rapid reproductive development, presumably to promote mating success during their first reproductive season. Rodents born late in the breeding season suspend somatic growth and puberty until the following vernal breeding season. We tested the hypothesis that perinatal day lengths have similar enduring effects on the immune system of rodents. Siberian hamsters (Phodopus sungorus) were maintained prenatally and until weaning (21 days) in either SDs (8 h light:16 h dark) or long days (LD) (16 h light:8 h dark), then they were weaned into either the opposite photoperiod or maintained in their natal photoperiod, forming four groups (LD-LD, LD-SD, SD-LD, and SD-SD). After 8-wk in these conditions, cell-mediated immune activity was compared among groups. SD-SD hamsters of both sexes enhanced immune function relative to all other groups. The reproductive effects of perinatal photoperiod were not evident by the end of the experiment; circulating testosterone and cortisol sampled at the end of the experiment reflected the postweaning, but not the perinatal photoperiod. This experiment demonstrates long-lasting organizational effects of perinatal photoperiod on the rodent immune system and indicates that photoperiod-induced changes in the immune system are dissociable from changes in the reproductive system.

Intercellular adhesion molecule 1 (ICAM-1) plays an important role in the transmigration of polymorphonuclear neutrophils (PMN) in sepsis. Moreover, the transmigration rate of leukocytes from the blood via endothelial adhesion molecules into tissues correlates with the severity of multi organ failure. We examined the effect of the deletion of the ICAM-1 gene in polymicrobial sepsis using a cecal ligation and puncture (CLP) sepsis model in mice. Twenty male ICAM-1 knockout (KO) mice and 20 wild-type (WT) male C57BL/6 mice were studied. CLP was performed. At several time points during a 96-hour postoperative observation period, we measured mortality, body weight, and temperature. The delayed type of hypersensitivity (DTH) reaction was determined by pinna swelling after sensitization with 50 microL of dinitrofluorobenzene (DNFB) 1%. Lymphocyte subpopulations (CD4, CD8, and CD56) and cytokines [tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and interleukin-10 (IL-10)] were measured using flow cytometry and ELISA testing, respectively. Also, a histologic examination of the liver and lung was performed. CLP-induced mortality was lower in the ICAM-1 group compared to normal mice (5% vs 45.0%). So were the ratios of lymphocyte subpopulations in the KO versus the WT group [CD4: 16.4 +/- 1.6% vs 25.7 +/- 4.7%; CD8: 18.3 +/- 1.4% vs 34.9 +/- 2.9%; natural killer (NK) cells: 5.6 +/- 0.3% vs 49.5 +/- 0.7%; P < 0.01]. And also the cytokine blood levels of the KO mice were significantly lower versus the WT mice (TNF-alpha: 67.2 +/- 42.2 vs 823.9 +/- 170.5 pg/mL; IL-1beta: 5.9 +/- 0.9 vs 296.2 +/- 66.2 pg/mL; IL-6: 223.1 +/- 48.8 vs 3062.5 +/- 1222.8 pg/mL; IL-10: 34.6 +/- 5.8 vs 1565.6 +/- 448.8 pg/mL; P < 0.01). With respect to the histology, significantly less leukocyte invasion and organ damage (eg, hydropic degeneration) were present in the ICAM-1-/- group compared to controls in liver and lung tissues. The DTH reaction was significantly decreased in ICAM-1-/- mice versus WT mice (0.34 vs 0.41 mm; P < 0.05). Our results demonstrate a significant reduction of mortality after septic challenge in ICAM-1-/- mice compared to normal mice. This is associated with a decrease in lymphocyte subpopulations, cytokine levels, and DTH type 4 reaction, possibly reflecting an overall attenuation of the immune system.

Uric acid, the naturally occurring degradation product of purine metabolism, is a danger signal, driving maturation of dendritic cells. It is well known that uric acid crystals display potent proinflammatory properties--the cause of gout--whereas the biological properties of soluble uric acid are less well documented. We have demonstrated previously that nucleic acids of endogenous and exogenous origin display proinflammatory properties. The aim of the present study was to assess the impact of soluble uric acid on in vivo inflammatory responses. Mice were administered with uric acid suspension in saline or saline alone prior to induction of neutrophil-mediated inflammation, delayed-type hypersensitivity, histamin-induced edema (measure of vasodilation capacity), as well as double-stranded (ds)RNA-triggered arthritis. Frequency and severity of arthritis were decreased significantly in mice exposed to dsRNA and simultaneously treated with uric acid as compared with saline-treated controls. Also, granulocyte-mediated inflammatory response and vasodilation capacity were reduced significantly in mice treated with uric acid as compared with their control group. The data suggest that down-regulation of inflammation was mediated by skewing the inflammatory response from the peripheral sites to the peritoneal cavity and down-regulating vasodilatatory capacity and thereby affecting leukocyte migration. In contrast, the T cell-mediated delayed-type hypersensitivity reaction was not affected significantly in mice exposed to uric acid. These findings demonstrate that uric acid displays a potent, distant anti-inflammatory effect in vivo. This property seems to be mediated by down-regulation of neutrophil influx to the site of inflammatory insult.

Late allergic reactions (LAR) following allergen challenge occur in different compartments. We studied the kinetics of nasal and bronchial nitric oxide (NO) in mild asthmatics after allergen challenge. Twelve males with intermittent asthma (28 yr, FEV1 97% of predicted, PC20methacholine <8 mg/ml) and known LAR after bronchial allergen challenge underwent nasal and bronchial allergen provocation using the same allergen separated by a washout of 3 weeks. Nasal and bronchial NO were measured before challenge, during early (EAR) and late phase reactions, and 24 h after allergen. The mean (sem) maximum fall of FEV1 at EAR was 31.9+/-3.2% (P=0.001), and 17.6+/-2.2% (P=0.004) during LAR. All patients developed nasal EAR (max. fall in nasal rhinomanometric flow 64.8+/-7.6% of baseline) after nasal challenge, and 10 patients demonstrated nasal LAR with a fall in nasal flow of 65.9+/-6.6% (both P=0.002, respectively). During EAR, there was stronger reduction of nasal (-19.2+/-6.2%,P=0.039) than bronchial NO (-6.9+/-5.2% of baseline, P=ns). In contrast, bronchial NO also tended to decrease during bronchial LAR (-8.8+/-6.8%,P=ns), while nasal NO slightly increased non-significantly (+17+/-10.8%, P=ns). After 24 h, bronchial NO was significantly elevated (+78.1+/-40.1%, P=0.039), whereas nasal NO was unchanged (+6.1+/-15.1%, P=ns). The intraindividual difference between bronchial and nasal changes of NO during LAR, but not EAR or after 24 h, was significant (lung vs. nose: -35.6+/-14.1% relative difference, P=0.039). Despite similar functional responses in nose and bronchi, nasal NO kinetics following allergen challenge differ from bronchial NO. The concise mechanisms accounting for this discrepancy warrant further investigations.

Social cues may interact with photoperiod to regulate seasonal adaptations in photoperiod-responsive rodents. Specifically, photoperiod-induced adjustments (e.g., reproduction and immune function) may differ among individuals in heterosexual pairs, same-sex pairs, or isolation. Heterosexual cues may be more influential, based on their potential fitness value, than same-sex cues or no social cues. The present study examined the effects of pair (with a male or female) or individual housing on reproductive and immune responses in male white-footed mice (Peromyscus leucopus) maintained in long or short photoperiods. Female pairing did not affect reproductive responses in short-day males. In long days, however, the presence of a female increased both testosterone concentrations and testes mass compared with individually housed and male-paired mice, respectively. Short-day, individually housed males enhanced delayed-type hypersensitivity (DTH) responses compared with single-housed mice in long days, but all paired groups decreased DTH responses regardless of photoperiod. The lack of enhanced DTH response in male mice paired with females coincided with reduced circulating corticosterone concentrations in both photoperiod treatments. Together, these results suggest that social environment may have important modulatory effects on photoperiod-regulated immune responses in male white-footed mice.

Human CD99 is a small highly O-glycosylated cell-surface protein expressed on most leukocytes. It was recently found to be expressed at endothelial cell contacts and to participate in the transendothelial migration (TEM) of monocytes in vitro. In order to analyze the physiologic relevance of CD99 in vivo we searched for the mouse homolog. We cloned a mouse cDNA coding for a protein 45% identical in its sequence with human CD99. Based on the cDNA, we generated antibodies against this mouse homolog of CD99, which detected the antigen on most leukocytes, on endothelia of various tissues, and at cell contacts of cultured endothelial cells. Cell aggregation of CD99-transfected Chinese hamster ovary (CHO) cells was completely blocked by anti-CD99 antibodies. The same antibodies inhibited TEM of lymphocytes in vitro, independent of whether T cells or endothelial cells were preincubated with antibodies. In a cutaneous delayed-type hypersensitivity (DTH) reaction, anti-CD99 antibodies inhibited the recruitment of in vivo-activated T cells into inflamed skin as well as edema formation. We conclude that mouse CD99 participates in the TEM of lymphocytes and in their recruitment to inflamed skin in vivo. This establishes CD99 as a valid target for interference with cutaneous inflammatory processes.

Aim: To explore the pathophysiological significance of delayed type hypersensitivity (DTH) reaction in mouse gastrointestinal tract induced by an allergen 2,4-dinitrochlorobenzene (DNCB)., Methods: BALB/c mice were randomly divided into control and DTH(1-6) groups. After sensitized by DNCB smeared on the abdominal skin, the mice were challenged with DNCB by gavage or enema. The weight, stool viscosity and hematochezia were observed and accumulated as disease active index (DAI) score; the gastrointestinal motility was represented by active charcoal propulsion rate; the colon pathological score was achieved by macropathology and HE staining of section prepared for microscopy; and the leukocyte migration inhibitory factor (LMIF) activity was determined by indirect capillary assay of the absorbance (A) of migrated leukocytes., Results: Active charcoal propulsion rates of small intestine in the DNCB gavages groups were significantly higher than that in the control group (P<0.01). The DAI scores and pathological score in DNCB enema groups were also higher than that in the control group (P<0.05), and there were significant rises in LMIF activity in DNCB enema groups as compared with control groups (P<0.01)., Conclusion: Mouse gastrointestinal DTH reaction could be induced by DNCB, which might facilitate the mechanism underlying the ulcerative colitis.

To understand the mechanisms involved in immunological tolerance to skin-associated antigens, we have developed transgenic (Tg) mice that express a model self-antigen, membrane-bound chicken ovalbumin (OVA), under the control of a keratin 14 (K14) promoter. K14-mOVA Tg mice express OVA mRNA in the epidermis, and appear normal. K14-mOVA Tg mice failed to mount T cell and delayed type hypersensitivity reactions to OVA, suggesting that the Tg mice were tolerant to OVA. Skin dendritic cells, including Langerhans cells, may contribute to the tolerance induction because migratory skin DC derived from K14-mOVA efficiently activated CD8(+) T cells from OVA-specific T-cell receptor (Va2/Vb5) Tg (OT-I) mice. OT-I cells expanded and accumulated in skin-draining lymph nodes after intravenous injected into K14-mOVA mice and exhibited activation markers. Graft-versus-host disease-like skin lesions appeared in K14-mOVA mice by day 7 after injection of OT-I cells. These studies demonstrate that K14-mOVA Tg mice are susceptible to an autoimmunelike skin disease induced by passively transferred naïve CD8(+) OVA T-cell receptor Tg T cells, and serve as a good model for understanding self-tolerance and for the investigation of the pathogenesis, treatment and potential prevention of cell-mediated autoimmune reactions in skin.

Animal models exhibiting high homology with humans at the genetic and pathophysiological levels will facilitate identification and validation of gene targets underlying asthma. In the present study, a nonhuman primate model of allergic asthma was developed by sensitizing cynomolgus monkeys to dust mite antigen. Sensitization elevated allergen-specific serum IgE and IgG levels, and peripheral blood mononuclear cells isolated from sensitized animals released IL-4, IL-5, and IL-10, but not IFN-gamma. Aerosolized allergen decreased dynamic compliance and induced airway inflammation and hyperresponsiveness to aerosolized histamine. Albuterol and dexamethasone inhibited the airway constriction and allergen-induced inflammation, respectively. Airway wall remodeling that included goblet cell hyperplasia, basement membrane thickening, and smooth muscle hypertrophy was particularly evident in neonatally sensitized animals. In contrast to animals sensitized as adults, neonatally sensitized animals exhibited increased sensitivity to adenosine and larger allergen-induced changes in airway resistance and dynamic compliance. These results demonstrate that sensitization of cynomolgus monkeys with dust mite induces asthmalike symptoms, some of which may be dependent on age at the time of sensitization.

The mechanism(s) underlying stress-induced colonic hypersensitivity (SICH) are incompletely understood. Our aims were to assess the acute and delayed (24 h) effect of water avoidance (WA) stress on visceral nociception in awake male Wistar rats and to evaluate the role of two stress-related modulation systems: the substance P/neurokinin-1 receptor (SP/NK(1)R) and the corticotropin-releasing factor (CRF)/CRF(1) receptor (CRF/CRF(1)R) systems, as well as the possible involvement of the sympathetic nervous system. Visceral pain responses were measured as the visceromotor response to colorectal distension (CRD) at baseline, immediately after WA and again 24 h later. The NK(1)R antagonists RP-67580 and SR-140333 and the CRF(1)R antagonist CP-154526 were injected 15 min before WA or 1 h before the CRD on day 2. Chemical sympathectomy was performed by repeated injection of 6-hydroxydopamine. WA stress resulted in a significant increase in the visceromotor response on day 2, but no change immediately after WA. Injection of CP-154526 abolished delayed SICH when applied either before WA stress or before the CRD on day 2. Both NK(1)R antagonists only decreased SICH when injected before the CRD on day 2. Chemical sympathectomy did not affect delayed SICH. Our results indicate that in male Wistar rats, both NK(1)R and CRF(1)R activation, but not sympathetic nervous system activation, play a role in the development of SICH.

Changes in day length affect several measures of immunity in seasonally breeding mammals. In Siberian hamsters (Phodopus sungorus), short day lengths suppress specific secondary antibody responses to the keyhole limpet hemocyanin (KLH) antigen and enhance cutaneous delayed-type hypersensitivity (DTH) responses to dinitrofluorobenzene (DNFB). These experiments tested whether day length affects secondary antibody and DTH responses by altering immune function solely during the interval after the initial exposure to each antigen, solely during the interval after the second exposure, or during both stages of the respective immune responses. Adult male Siberian hamsters were exposed to either a long (16 h light/day; LD) or a short (8 h light/day; SD) photoperiod for 7.5 wk before receiving an initial exposure to each antigen (KLH injection, cutaneous DNFB treatment; separate groups of animals for each antigen). A subset of LD hamsters was transferred to the SD photo-period, and a subset of SD hamsters was transferred to the LD photoperiod. Other hamsters remained in LD or SD. Eight weeks later, all hamsters were challenged with a second subcutaneous injection of KLH or a second application of DNFB to the ear, and immune responses were measured. Exposure to SD during the primary antibody response did not affect secondary IgG responses, but SD exposure during the secondary response significantly suppressed IgG production independent of day length during the initial KLH treatment. In contrast, exposure to SD during the DNFB challenge enhanced the ensuing DTH response, but this enhancement depended on the photoperiod prevailing during the initial exposure. Exposure to SD during the sensitization stage did not enhance DTH in hamsters subsequently exposed to LD. The data suggest that short photoperiods have enduring effects on immune responsiveness and on the establishment and retention of immunological memory.

A periurban outbreak of visceral leishmaniasis (VL) caused by the protozoan Leishmania chagasi is ongoing outside Natal, northeast Brazil. Manifestations range from asymptomatic infection to disseminated visceral disease. Literature reports suggest that both genetic and environmental factors influence the outcome of infection. Due to the association of the tumor necrosis factor (TNF) locus with other infectious diseases, we examined whether polymorphic alleles at this locus are associated with the outcome of L. chagasi infection. Neighborhoods with ongoing transmission were identified through patients admitted to local hospitals. Altogether, 1,024 individuals from 183 families were classified with the following disease phenotypes: (i) symptomatic VL, (ii) asymptomatic infection (positive delayed-type hypersensitivity [DTH+]), or (iii) no evidence of infection (DTH-). Genotypes were determined at a microsatellite marker (MSM) upstream of the TNFB gene encoding TNF-beta and at a restriction fragment length polymorphism (RFLP) at position -307 in the promoter of the TNFA gene encoding TNF-alpha. Analyses showed that the distribution of TNFA RFLP alleles (TNF1 and TNF2) and the TNF MSM alleles (TNFa1 to TNFa15) differed between individuals with VL and those with DTH+ phenotypes. TNF1 was transmitted more frequently than expected from heterozygous parents to DTH+ offspring (P = 0.0006), and haplotypes containing TNF2 were associated with symptomatic VL (P = 0.0265, transmission disequilibrium test). Resting serum TNF-alpha levels were higher in TNF1/2 heterozygotes than in TNF1/1 homozygotes (P < 0.05). These data led us to hypothesize that an individual's genotype at the TNF locus may be associated with whether he or she develops asymptomatic or symptomatic disease after L. chagasi infection. The results preliminarily suggest that this may be the case, and follow-up with larger populations is needed for verification.

This report describes the frequency and characteristics of serious or life-threatening hypersensitivity reactions to the tuberculin skin test over an 11-year period through November 2000. There were 24 reports and no deaths, indicating that such reactions are rare (0.08 reported reactions per million doses of tuberculin).

It is well established that ultraviolet radiation has immunomodulatory effects that may be involved in skin cancer. Recent studies have shown that ultraviolet A radiation (320-400 nm) as well as ultraviolet B (290-320 nm) is immunosuppressive. This means sunscreens that mainly absorb ultraviolet B (protection against erythema) may be less effective in preventing ultraviolet radiation-induced immunosuppression than broad-spectrum products. We have studied the effects of ultraviolet A exposure on the human delayed-type hypersensitivity response and compared the efficacy of sunscreens having different levels of ultraviolet A protection under both solar-simulated radiation and outdoor real-life solar exposure conditions. Delayed-type hypersensitivity was assessed using recall antigens. In a first study, two groups of volunteers were exposed to ultraviolet A (either full spectrum ultraviolet A or ultraviolet A1) without prior application of sunscreen and they were shown to exhibit significantly reduced delayed-type hypersensitivity responses. In order to compare the efficacy of sunscreens in preventing photoimmunosuppression, three groups of subjects received 10 cumulative exposures to solar-simulated radiation; one group was exposed unprotected and the other two were exposed after being applied either a ultraviolet B or a broad-spectrum sunscreen, each with the same sun protection factor 9, but with different ultraviolet A protection factors 9 and 2. Then, an outdoor study was conducted in which delayed-type hypersensitivity was assessed before and after six daily exposures. Two different groups of subjects were treated with one of two sunscreens having the same sun protection factor 25 but different ultraviolet A-protection factors. In unprotected volunteers, responses to delayed-type hypersensitivity tests were significantly reduced irrespective of ultraviolet exposure conditions (full spectrum ultraviolet A, ultraviolet A1, solar-simulated radiation). The ultraviolet B sunscreen failed to protect from solar- simulated radiation-induced immunosuppression. In contrast, the broad-spectrum sunscreen having the same sun protection factor but providing high protection in the ultraviolet A range significantly reduced local ultraviolet-induced immunosuppression and prevented the distal effects. In the outdoor study, as compared with delayed-type hypersensitivity responses obtained before sun exposure, no alteration of immune response was detected when the skin was protected by broad-spectrum sunscreen sun protection factor 25 and ultraviolet A-protection factor 14. Conversely, a broad-spectrum sunscreen sun protection factor 25 ultraviolet A-protection factor 6 failed to protect against the sun-impaired response. The above studies clearly demonstrate the role of ultraviolet A in the induction of photoimmunosuppression together with the need for sunscreen products providing efficient photoprotection throughout the entire ultraviolet spectrum.

The saliva of bloodsucking arthropods contains a large array of pharmacologically active compounds that assist hematophagy. Arthropod saliva is also responsible for causing uncomfortable allergic responses in its vertebrate hosts. In this article, we investigate whether the sand fly Phlebotomus papatasi, known to produce a strong delayed-type hypersensitivity (DTH) in humans, could benefit from, and possibly adaptively induce, this response in their vertebrate hosts. In this study, we show that flies fed on humans to completion nearly twice as fast in DTH sites as compared with normal skin sites. DTH sites had significantly larger blood flow as measured by the laser Doppler method. Sand flies feeding at sites in mouse ears that had a DTH response also fed faster than at normal sites. We conclude that in the case of P. papatasi, and possibly other arthropods such as fleas and bed bugs, the strong saliva-induced DTH response may reflect an adaptation of the fly to manipulate host immunity for the insect's own advantage.

To identify predictors of the late asthmatic response (LAR), we reviewed data from 60 asthmatic subjects who had undergone allergen challenge over the past 5 yr (33 females, age 31.4 +/- 6.7 yr [mean +/- SD], FEV(1) 90% +/- 14% predicted). Variables considered likely predictors of LAR included baseline FEV(1), PC(20) methacholine (PC(20)), sputum eosinophil percent, and the decrease in FEV(1) within 20 min of allergen challenge. A LAR (FEV(1) >/= 15% fall between 3 and 7 h after challenge) was documented in 57% of subjects. A variety of logistic regression methods revealed a significant inverse association between LAR and PC(20) (odds ratio [OR] = 0.14 [95% CI = 0.03-0.66]) and a positive association between LAR and the decrease in FEV(1) at 20 min (OR = 1.18 [1.04 -1.33]). Classification tree analysis revealed that a threshold of 0.25 mg/ml for PC(20) was most predictive of LAR; LAR developed in 87% of those with PC(20) 0.25 mg/ml (n = 37). Notably, in subjects with PC(20) > 0.25 mg/ml, the incidence of LAR increased from 38% to 57% if the allergen-induced decline in FEV(1) at 20 min was >/= 27%. Surprisingly, baseline FEV(1) and percent eosinophils in induced sputum were not significantly associated with LAR. We conclude that a threshold value of 0.25 mg/ml for PC(20) methacholine is a good predictor of LAR. Measuring the PC(20) methacholine may be useful as a screening method to improve the efficiency of identifying asthmatic subjects with a LAR.

Intravenous administration of a humanized monoclonal antibody of IgE (E25) attenuates the early and late phase response to inhaled allergen in allergic asthmatic subjects. To test whether direct delivery of E25 to the airway might have the same effect, we conducted a randomized, double-blind, three group study in 33 subjects with mild allergic asthma (20 to 46 yr of age, 21 men, FEV(1) > 70% predicted). The airway responses to aerosolized allergen were determined at baseline, after 2 and 8 wk of once daily treatment with aerosolized placebo (n = 11), aerosolized E25 1 mg (n = 12), or aerosolized E25 10 mg (n = 10), and after 4 wk of treatment withdrawal. We found that E25 was detectable in the serum during aerosol treatment, although serum IgE did not change significantly in any of the three groups during treatment. In addition, both doses of E25 were no more effective than placebo in attenuating the early phase responses to allergen at both times during treatment. Although aerosolized E25 was generally well tolerated, one subject receiving aerosolized E25 10 mg daily was found to have serum IgG and IgA antibodies to E25. We conclude that aerosol administration of an anti-IgE monoclonal antibody does not inhibit the airway responses to inhaled allergen in allergic asthmatic subjects. We speculate that the observed lack of efficacy may be due to the inability of aerosol route of delivery to result in high enough concentrations of E25 in the tissue compartments surrounding IgE effector cells to neutralize IgE arising from local airway and pulmonary sources and IgE arising from the vascular space. Additionally, the aerosol route of delivery of monoclonal antibodies may be more immunogenic than the parenteral route.

Purpose: To determine whether cultured retinal pigment epithelial (RPE) cells implanted in the subconjunctival space induce an immune response against autoantigens and whether an active downregulation is achieved by RPE grafts placed in the anterior chamber and within the subretinal space., Methods: Cultured RPE cells from eyes of newborn C57BL/6 mice were implanted in the subconjunctival space, the anterior chamber, or the subretinal space of eyes of adult C57BL/6 mice. At postimplantation day 12, the recipients were evaluated for RPE-specific delayed hypersensitivity and examined clinically and histologically for evidence of rejection. To facilitate their identification, RPE cells were labeled with 5-bromodeoxyuridine, before intraocular transplantation., Results: Cultured RPE cells implanted in the subconjunctival space of syngeneic mice elicited an intense RPE-specific delayed hypersensitivity associated with a vehement cellular infiltration of the graft when examined at postimplantation day 12. By contrast, grafts in the anterior chamber and subretinal space displayed no evidence of rejection, and their recipients failed to display RPE-specific delayed hypersensitivity. Additionally, the spleens of these mice contained regulatory T cells that suppressed RPE-specific delayed hypersensitivity in naive syngeneic recipients., Conclusions: Cultured RPE cells can induce an immune response against autoantigens. Implantation of RPE cells in immune-privileged sites of the eye induces a deviant immune response that is associated with spleen cells that suppress RPE-specific delayed hypersensitivity and autoimmune rejection.

One thousand 5-wk-old male turkeys from each of two commercial strains (A and B) were grouped into low, medium, and high responders based on the cutaneous basophil hypersensitivity (CBH) response obtained 24 h after toe-web inoculation with 100 micrograms of phytohemagglutinin-P (PHA-P). The CBH response for Strain A was higher than strain B (P = 0.00001) and ranged from 0 to 1.95 mm, with a mean of 0.66, whereas the CBH response for Strain B ranged from 0 to 1.67 mm with a mean of 0.38. At 6 wk of age, 36 birds from each of the six response groups were inoculated into the left thoracic air sac with 1.5 x 10(7) cfu of an early log phase broth culture of Escherichia coli. Samples of 5 or 10 birds were necropsied from each of the six groups at 7, 14, 28, and 42 d postinfection (PI). Birds were scored for air-sacculitis/pericarditis (AS) and turkey osteomyelitis complex (TOC). Overall mortality of birds inoculated with E. coli was 31%. There were no mortalities in unchallenged controls. Strain A had significantly higher Week 1 mortality, marginally higher overall mortality (P = 0.1), and higher AS scores than Strain B. There were no TOC lesions detected until 7 d PI, after which all mortalities had TOC lesions in multiple sites. The differences in CBH response within each strain were not clearly correlated to E. coli susceptibility. However, these data suggest that air sac inoculation of E. coli can provide a useful model for the study of TOC. The greater incidence of disease in Strain A indicates that an enhanced inflammatory response may increase susceptibility to E. coli septicemia.

aFGF injection s.c. once a week into SAMP8 was begun at 3 weeks after birth and continued for 10 months. Saline was injected as a control. learning and memory and cellular immunological functions in the aFGF group were enhanced significantly, while those of the saline group deteriorated. 1. The number of cholinergic neurons was decreased by less than 20% and ChAT activity in individual neurons in the medial septum which send monosyonaptic terminals to the hippocampus was significantly decreased in the saline group, but not so much in the aFGF group. 2. The respective densities of muscarinic and aFGF receptors, on the hippocampal neurons were significantly higher in the aFGF group than in the saline group. 3. The LTP in hippocampal slice preparations was significantly facilitated in the aFGF group, but not in the saline group. 4. The DTH, (T cell immune response) measured at the end of the 2nd and 7th months were reduced in the 7th month as compared with the 2nd month in the saline group, but aFGF group protected against this reduction. 5. These results show that aFGF provides protection against impairment of not only learning and memory but also the DTH immunoreactivity in SAMP8.

Leukocyte rolling and emigration in response to inflammatory stimuli appears to involve both E-selectin- and P-selectin-dependent adhesion, which suggests that these molecules have overlapping functions. To clarify their relative contributions in chronic inflammation, we examined delayed-type contact hypersensitivity (DTH) responses in P-selectin, E-selectin, and E-/P-selectin-deficient mice. Oxazolone-induced increases in ear thickness and ear weight were equivalent in wild-type mice and in P-selectin and E-selectin mutants, but were significantly reduced in E-/P-selectin mutants. The number and area of microabscesses on the ears of E-/P-deficient mice were decreased by 72% and 93%, and the number of leukocytes invading the subdermal ear tissue was reduced. T cells from E-/P-deficient mice transferred oxazolone reactivity into naive wild-type mice. However, when donor T cells from wild-type mice were transferred into E-/P-selectin-deficient mice, the DTH response was significantly impaired. These results show that leukocyte recruitment into a subacute inflammatory reaction can occur when either P-selectin or E-selectin is present, but is significantly reduced when both selectins are absent. Both P- and E-selectin are likely to play important roles in the development and maintenance of inflammatory diseases.

Physiological changes during late phase nasal responses after allergen challenge are difficult to establish and different criteria are used for the definition of a positive late phase nasal reaction. The objective of this study was to assess the value of whole body plethysmography in detecting changes in nasal airway resistance after allergen challenge and to suggest criteria for the definition of early and late phase nasal reactions. Nasal challenge with allergen was performed in 15 allergic patients. Nasal resistance was followed until 10 h after allergen challenge and on a control day using whole body plethysmography. The mean percentage changes in the inspiratory nasal resistance during the early phase period (0.25-2 h) and the late phase period (4-10 h) were significantly higher on the allergen challenge day than on the control day (p=0.001 and p=0.01, respectively). The mean percentage change in the inspiratory nasal resistance during the early and late phase period on the control day plus 2 times the standard deviation served as cut-off point for a positive reaction. Using this definition, all patients had early reactions and 7 of the 15 patients (47%) also had late reactions. We conclude that whole body plethysmography is a useful, noninvasive method for the measurement of the physiological changes in the nose following allergen challenge.

To characterize further the neural involvement in local immune reactions, we evaluated the effect of intrathecal NMDA-receptor blocker dizocilpine maleate (MK-801) on the peripheral immune response itself and on spinal cord c-fos expression induced by the delayed-type hypersensitivity (DTH) response. Immune challenge took place in the hind paw ipsilateral or contralateral to an injured sciatic nerve in both previously sensitized and immune-naive animals. An enhanced immune response was observed bilaterally in the hind paws of animals subjected to unilateral mononeuropathy compared with sham-operated controls. In contrast, no such enhancement was observed when neuropathic animals were challenged in the front paws. The increased DTH response was blocked successfully by the intrathecal administration of an analgesic dose of MK-801. Compared with sham-operated animals, animals subjected to unilateral mononeuropathy showed both a differential distribution and an increase in the number of c-fos-labeled neurons in the dorsal horn of the L3-L5 spinal cord segments after immune challenge. This was observed irrespective of whether the challenge took place ipsilateral or contralateral to the injured nerve. In addition to reversing the changes in immune response, intrathecal administration of MK-801 reversed the pattern of c-fos immunoreactivity in the spinal cord after immune challenge in neuropathic animals. These data suggest that select groups of spinal cord neurons participate in enhancing the peripheral immune response to a specific antigen in neuropathic animals and that this enhancement involves central NMDA receptors.

Animal models with selective genetic immunodeficiencies are useful tools to identify pathogenic mechanisms of disease. Resistant (C57BL/6F 129/J) (H-2b) mice are rendered susceptible to Theiler's murine encephalomyelitis virus-induced demyelination by genetic disruption of the beta 2 microglobulin gene [beta 2 m(-l-)]. The absence of beta 2 m prevents the expression of major histocompatibility complex class I molecules and normal levels of functional CD8+ T cells. We tested whether genetic depletion of beta 2 m would permit CNS remyelination after chronic demyelination induced by the Daniel's strain of Theiler's virus. In contrast to the minimal spontaneous remyelination observed in SJL/J mice after infection with the Daniel's strain of Theiler's virus, chronically infected beta 2 m(-I-) mice showed extensive and progressive spontaneous CNS remyelination at 6, 12, and 18 months after infection. Spontaneous remyelination by both oligodendrocytes and Schwann cells occurred despite the presence of persistent virus antigen and RNA, but was associated with diminished virus-specific humoral and delayed-type hypersensitivity responses. These experiments support the hypothesis that the immune response inhibits myelin regeneration after virus-induced CNS demyelination.

In developing a novel model for studies of the allergen-induced late-phase airways obstruction, by using the pig, the importance of endogenous cortisol levels was examined by the use of metyrapone, a cortisol-synthesis inhibitor. Specific-pathogen free pigs were actively sensitized with Ascaris suum allergen. One group of pigs was treated with a constant infusion of metyrapone in order to maintain low levels of plasma cortisol. Ascaris suum allergen was nebulized into the lower airways and plasma cortisol and catecholamine levels, total lung resistance and dynamic compliance, blood gases and pH, and blood flow in the bronchial circulation were continuously recorded for 8 h. At the time of allergen challenge, the plasma cortisol levels in sensitized pigs were 455 +/- 37 nM and 40.1 +/- 3.8 nM in non-metyrapone-treated and metyrapone-treated pigs, respectively. No difference was seen between the magnitude of the acute bronchoconstrictor response in the two groups. A late airways obstruction, starting at about 4 h, developed only in pigs with low cortisol levels, whereas a late increase in blood flow in the bronchial circulation was seen in both groups, even if a late airways obstruction was absent. Plasma adrenaline did not seem to influence the late-phase reaction. These results suggest that endogenous cortisol levels, but not adrenaline, modify the late response to allergen in the pig. Furthermore, it is suggested that the pig is a suitable model for studies of allergic reactions in the airways, if metyrapone is used to keep plasma cortisol levels within a normal range.

Delayed-type hypersensitivity (DTH) reactions are initiated by sensitized T cells. Their progression is dependent upon the local release of various autacoids, including cytokines and eicosanoids, by T cells, infiltrating inflammatory cells, and resident tissue cells. 12(R)-hydroxy-5,8,14-eicosatrienoic acid [12(R)-HETrE], an eicosanoid produced by skin and cornea, possesses potent proinflammatory properties at picomolar concentrations including vasodilation, increase in membrane permeability, neutrophil chemotaxis, and angiogenesis. Because DTH reactions are associated with many of these same phenomena, we examined the effect of 12(R)-HETrE and related 12-hydroxyeicosanoids on the expression of DTH to purified protein derivative of tuberculin in sensitized guinea pigs. In the absence of purified protein derivative of tuberculin, none of the eicosanoids evoked erythema or edema after intradermal injection at doses up to 100 pmol. When injected together with purified protein derivative of tuberculin, 12(R)-hydroxy-5,8,10,14-eicosatetraenoic acid [12(R)-HETE], but not its enantiomer 12(S)-HETE, significantly inhibited macroscopic expression of delayed reactivity (erythema) only at the highest dose tested, 10 pmol. In contrast, 12(R)-HETrE significantly enhanced expression of DTH at doses between 1 fmol and 1 pmol (50% and 30% increases above control, respectively). Its stereoisomer, 12(S)-HETrE, did not enhance DTH at any tested dose, but was able to block the activity of 12(R)-HETrE when injected simultaneously. Enhancement or inhibition of visible skin responses was not associated with qualitative or quantitative changes in cellular infiltrates at the reaction site. 12(R)-HETrE had no effect on the nonimmunologic inflammatory skin reaction induced by phorbol myristate acetate, suggesting selectivity toward DTH. We conclude that 12(R)-HETrE enhances DTH via a yet to be determined mechanism and that its stereoisomer, 12(S)-HETrE, may be a useful antagonist for studying the inflammatory actions of this eicosanoid.

Oral and intrathymic exposure to antigen can each induce systemic antigen-specific immune tolerance, but the mechanisms have not been well defined. We studied the effects that the route of exposure to antigen has on the mechanisms of tolerance in vivo using synthetic polymorphic class II major histocompatibility complex (MHC) peptides in a skin delayed-type hypersensitivity (DTH) response model. Lewis rats were immunized by injection in the footpad with synthetic peptides (RT1.Bu and/or RT1.Du) derived from the hypervariable domain of MHC class II beta chain of the Wistar-Furth rat in complete Freund's adjuvant and challenged 2 weeks later by injection in the ear with the MHC peptides. An "oral" group received the peptide mixture by gavage (100 micrograms/day for 5 days) 3 days before immunization, and an "intrathymic" group received a single intrathymic injection of 100 micrograms of peptides 48 hours before immunization. Oral therapy reduced the DTH response to 23 +/- 7%, and intrathymic exposure reduced the DTH response to 26 +/- 6% (P < 0.001) as compared with control DTH responses of unmodified Lewis animals. Immunohistological evaluation of DTH skin lesions showed that oral and intrathymic therapy each decreased mononuclear cell infiltration, fibrin deposition, and endothelial activation when compared with that seen in control rats. In contrast, while both protocols markedly reduced interleukin (IL-2) and interferon-gamma expression, they had differing effects on local expression of IL-4, transforming growth factor-beta, IL-2R, and CD45RC (a possible discriminant between Th1 and Th2 cells in rats). Oral therapy was associated with increased expression of IL-4 and preservation of transforming growth factor-beta expression by residual IL-2R+, CD45RC- mononuclear and endothelial cells, whereas thymic exposure suppressed essentially all features of immune activation including IL-2R induction and cytokine expression. Our data a) document the detailed pattern of cytokine expression and mononuclear and endothelial cell activation markers during DTH responses and b) confirm that oral tolerance is associated with immune deviation to a predominance of Th2 cell function, whereas intrathymic tolerance may be mediated by T-cell anergy or clonal deletion.

Gastrointestinal symptoms occur in a large number of patients with food allergies. Immediate hypersensitivity mechanisms may give rise to the nausea, vomiting, abdominal pain, and diarrhea experienced by these patients. However, there are limited human data about the pathophysiological basis for these symptoms. Most of the available information comes from a variety of animal models. This article reviews the literature using models of intestinal food hypersensitivity, as well as human studies, that have contributed to our understanding of the pathophysiological mechanisms in gastrointestinal food hypersensitivity.

Airway responsiveness to inhaled methacholine was assessed before and after bronchial challenge with ultrasonically nebulized hyperosmolar saline (UNHS), and these changes were correlated with the development of late asthmatic responses (LAR). Sixteen subjects with mild to moderate asthma had two consecutive methacholine challenges before and one after a cumulative-dose challenge with UNHS. Twelve of these subjects also had a single-dose hyperosmolar challenge to document the occurrence of LAR and determine if UNHS had a significant cumulative-dose effect. If a LAR was observed, a control day without challenge completed the study. Responsiveness to methacholine was similar on the 2 baseline methacholine challenges with a provocative concentration producing a 20% fall in forced expiratory volume in one second (PC20) (mean +/- SEM) of 1.11 +/- 0.94 and 1.16 +/- 0.94 mg.ml.1 (r: 0.98). However, it was significantly increased after the inhalation of UNHS with a PC20 (mean +/- SEM) of 0.57 +/- 1.00 mg.ml.1 (p less than 0.001). Two subjects developed a late fall in forced expiratory volume in one second (FEV1) of 19 and 46% after hyperosmolar challenge. In this last subject, the LAR, not reproduced on the control day, was associated with a marked post-UNHS change in PC20, going from a baseline of 4.4 to 0.7 mg.ml.1 after UNHS. The % fall in FEV1 following the dose-response hyperosmolar challenge and the single-dose hyperosmolar challenge were not different, with mean values +/- SEM of 34.9 +/- 2.2 and 35.8 +/- 4.1, respectively, (p greater than 0.5). In conclusion, airway responsiveness to methacholine may increase following hyperosmolar saline inhalation, often unrelated to LAR.

The delayed-type hypersensitivity reaction (DHR) in human skin is prototypic for many inflammatory dermatoses. However the cellular events that precede gross lesion formation are unknown. In this study, inflammatory cell populations and adhesion molecule expression in early phases of DHR elicited by 2,4-dinitrochlorobenzene were evaluated. The first discernible event (at 1 hour) was mast cell degranulation, followed by induction of endothelial leukocyte adhesion molecule (ELAM-1) expression on dermal postcapillary venules at 2 hours. Endothelial leukocyte adhesion molecule expression peaked at 24 hours and declined by 48 hours. In contrast, endothelial expression of intercellular adhesion molecule-1 (ICAM-1) remained at constitutive levels. Intrafollicular T-cell migration occurred independent of ICAM-1 expression and commenced as early as 4 hours after challenge. Mature, activated CD4-positive lymphocytes that expressed a helper-inducer/memory phenotype predominated in early lesions. These results demonstrate in vivo that mast cell degranulation, ELAM-1 expression, and memory T-cell-follicular interactions are key events in subclinical evolutionary stages of cutaneous DHR.

Two hundred twenty-one consecutive adult cardiac surgical patients were examined prospectively for nutritional protein state, acute phase protein response, and delayed hypersensitivity reaction in an attempt to identify patients at high risk for the development of sternal wound infection, which occurred in 6 patients (2.7%). There was no significant correlation between preoperative nutritional protein concentrations (retinol-binding protein, prealbumin, and transferrin) and acute phase protein levels (C-reactive protein, alpha 1-acid glycoprotein, and complements B and C3), nor a statistically significant relationship between nutritional state or acute phase protein response and the development of sternal infection. Preoperative complement C3 levels were elevated, however, in 80.0% of those in whom sternal infections developed compared with 30.6% of those with well-healed wounds. Similarly, postoperative concentrations of alpha 1-acid glycoprotein were elevated in 80.0% of those in whom sternal infections developed compared with 28.6% of those with well-healed wounds. There was no correlation between delayed hypersensitivity and the risk of sternal infection, nor between preoperative nutritional protein and acute phase protein values. Seventy-three percent of patients were anergic on postoperative day 2. Stepwise logistic regression showed that age, body weight, preoperative intensive care unit stay, repeat median sternotomy, internal mammary artery grafting, postoperative hemorrhage, and postoperative cardiac arrest correlated with the development of sternal infection, whereas transfusion requirement, reexploration for bleeding, and the operation performed did not. We conclude that routine delayed hypersensitivity testing is of no value in predicting high-risk cardiac surgical patients when the anergy battery is placed on the preoperative day. Although statistically insignificant, possibly due to the small number of patients in whom sternal infection developed in this study (type II error), a larger study might find preoperative complement C3 and post-operative alpha 1-acid glycoprotein levels to be predictive of patients at risk for the development of sternal wound infection. The final logistic model for the predicted risk 2%) of sternal wound infection is: PREDSWC = exp(EQ)/1 + exp(EQ) where EQ = (0.38 x age) + (0.24 x weight) + (5.42 x preop ICU) + (4.39 x redo) + (7.14 x IMA) + (4.49 x hemorrhage) + (8.81 x arrest) - 62.72, and where preop ICU, redo, hemorrhage, and arrest are defined as yes (1) or no (0), IMA-is defined as 0, 1, or 2, age is in years, and weight is in kilograms.

The present studies were designed to investigate the role of monocytes in the pathogenesis of fever in delayed hypersensitivity. Adherent rabbit blood monocytes (from both normal and sensitized donors) were separated on Ficoll-Hypaque gradients and incubated with antigen (Ag; ovalbumin) and sensitized draining-lymph-node lymphocytes (or their supernatants) from rabbits with delayed hypersensitivity, and release of endogenous pyrogen was assayed. Results indicated that monocytes are activated to produce endogenous pyrogen by Ag and suspensions of draining-lymph-node cells or by an agent (lymphokine) in the supernatants of sensitized lymphocytes preincubated with Ag. The release of lymphokine was Ag specific and was correlated with the skin test reactivity of the donor rabbits to the sensitizing Ag. No evidence was found that Ag-antibody complexes or (in the case of sensitized monocytes) cytophilic antibodies play a role in the activity of this lymphokine which appears to act selectively on monocytes rather than on granulocytes.

We have used an orthotopic graft model in the rat to study the histologic characteristics of corneal allograft rejection. Unrejected allogeneic grafts could not be distinguished from clear syngeneic grafts. Although donor Langerhans cells are necessary for the development of delayed-type hypersensitivity (DTH), the histopathological characteristics of rejecting corneal allografts in immunologically naive hosts were identical regardless of the presence or absence of donor Langerhans cells. By contrast, preimmunization had a dramatic effect on the histology of graft rejection. Untreated allografts placed onto pre-immunized recipients underwent a marked cellular necrosis accompanied by minimal inflammation that easily distinguished these grafts from the previous groups. These results suggest that neither the presence nor absence of DTH responsiveness correlates with the histopathological events that accompany corneal graft rejection. However, preimmunization leads to a different histologic pattern of rejection that is characterized by an intense cellular necrosis.

The response of six healthy young adults to tuberculin skin testing was studied. Five subjects developed a typical delayed-type hypersensitivity reaction to PPD with a local rise in skin temperature, and the sixth showed a less intense response; a considerable increase in blood flow velocity was seen in all reactions. All subjects showed a fall in pH in the dermis during the course of the reaction: in four subjects the pH minimum occurred at the time when the changes of erythema and induration were most prominent, in one subject the pH fall preceded the maximal clinical changes, and in the remaining subject a substantial fall in pH occurred with only transient erythema. It was concluded that the local tissue acidosis had resulted from the greatly increased metabolic demand of the lymphocytes and monocytes attracted into the dermis as part of the type IV delayed-type hypersensitivity reaction, and that the concurrent reactive hyperaemia was insufficient to clear the acidic metabolic products of the greatly increased cell population.

The involvement of mast cells in the elicitation of contact photosensitivity (CPS) was examined in mice treated with pharmacologic agents and in genetically mast cell-deficient W/Wv mice. Contact photosensitivity responses were diminished by pretreatment with reserpine, which may have been due to depletion of vasoactive amines in mast cells. This inhibition was almost reversed by the monoamine oxidase inhibitor, pargyline-HCl, which prevented reserpine-induced depletion of vasoactive amines such as serotonin. Defective CPS was also found in W/Wv mice, but not in their congenic littermates (+/+). Abnormal CPS in mast cell-deficient mice was due to a defect in the elicitation of CPS rather than a defect in the induction of effector T cells, since the ability to elicit CPS could be transferred to normal +/+ mice by photosensitized cells from mast cell-deficient mice. These findings favor the view that mast cells are involved in the elicitation of CPS.

Intercellular adhesion molecule-1 (ICAM-1), putatively expressed by antigen-presenting or target skin cells, is a ligand for the lymphocyte function-associated antigen (LFA-1) present on circulating lymphocytes. Immunohistochemistry of normal adult human skin using monoclonal antiserum to ICAM-1 demonstrated focal reactivity restricted to endothelium lining the dermal microvasculature. Delayed hypersensitivity responses elicited with dinitrochlorobenzene in the skin of the same subject were evaluated sequentially over a 96 h period using immunohistochemical and ultrastructural techniques. The first alteration observed consisted of mast cell degranulation within perivenular foci in the superficial dermis at 4 h after antigen challenge. Sparse superficial perivascular T-cell infiltrates were present by 24 h. Progressive staining for ICAM-1 was observed in microvascular endothelium and in dermal dendritic cells between 24 and 48 h. ICAM-1 expression was documented focally within the lower epidermis at 48 h and diffusely within the lower and upper epidermal layers at 96 h. ICAM-1 expression by keratinocytes was consistently associated with T-cell migration into the epidermis, whereas migration was never observed in the absence of ICAM-1 reactivity. Immunoelectron microscopy confirmed ICAM-1 to be exclusively present on endothelial cells, dermal dendritic cells, mononuclear cells, and keratinocytes, and permitted characterization of the patterns of membrane reactivity. ICAM-1 expression by epidermal cells appears to be closely linked to the progressive migration of T cells from the dermis into the epidermis that characterizes cutaneous delayed hypersensitivity.

1 The effects of the H2-receptor antagonist, metiamide, on two types of cell-mediated immune response in vivo was investigated in the guinea-pig, in a test of the hypothesis that H2-receptor antagonists would result in 'runaway' unregulated hypersensitivity reactions. 2 Metiamide in doses of 5 mg-125 mg/kg given by 6-hourly injection during sensitization and challenge did not modify the delayed hypersensitivity reaction to tuberculin. 3 Metiamide in doses of 25-125 mg/kg given by injection, 6-hourly throughout sensitization to dinitrofluorobenzene (DNFB) and subsequent challenge six days later, did not modify the contact sensitivity reaction to DNFB. 4 It is concluded that metiamide, given during these cell-mediated immune reactions in the guinea-pig, does not enhance cell-mediated hypersensitivity responses.

In continuing studies on the pathogenesis of fever in states of delayed hypersensitivity, we have investigated the conditions for the release of an endogenous pyrogen (EP)-inducing lymphokine from draining-lymph-node lymphocytes of rabbits with delayed hypersensitivity to bovine gamma globulin. Using doses of 4 X 10(7) to 5 X 10(7) blood leukocytes (BL) as a source of EP, we found that ratios of about 5:1 of viable lymphocytes to BL were required to stimulate the BL to produce detectable amounts of EP in vitro. Both irradiated lymphocytes (1,700 R) as well as those from steroid-treated donors retained their ability to activate BL when incubated with antigen, properties consistent with activated "T" lymphocytes. In experiments to determine effects of temperature and duration of incubation on lymphokine release, the maximum EP-releasing activity was found to be present in supernatants of sensitized lymphocytes incubated with antigen for 18 h at 37 degrees C. These studies have confirmed that sensitized lymphocytes release a soluble, pyrogen-inducing lymphokine when incubated with antigen and further demonstrate that tissue macrophages (Kupffer cells) as well as BL can be activated to produce EP in vitro by this agent.