COVID Arm After Moderna Booster in Healthcare Worker: A Case Report.

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.

Clinical Features and Management of "Phlebitis-like Abnormal Reaction" After Cyanoacrylate Closure for the Treatment of Incompetent Saphenous Veins.

BACKGROUND: Cyanoacrylate closure for the treatment of incompetent saphenous veins does not cause thermal damage and demonstrates satisfactory outcomes with rapid recovery. However, the characteristics of phlebitis-like abnormal reaction (PLAR), the most common adverse event after cyanoacrylate closure, have not been clarified. Moreover, it differs from typical phlebitis after thermal ablation. The objective of our study is to investigate the clinical features of PLAR after cyanoacrylate closure and to report its management. METHODS: A total of 160 patients with 271 incompetent saphenous veins (great saphenous veins, 201; small saphenous veins, 70) underwent cyanoacrylate closure with the VenaSeal™ system. We defined PLAR as any unusual skin condition that develops suddenly, such as erythema, itching, swelling, and pain/tenderness, over the treated veins several days after cyanoacrylate closure. Oral antihistamines and intravenous dexamethasone were administered to manage PLAR. RESULTS: Of the 271 treated veins, 69 experienced PLAR (25.4%). The mean time of occurrence was 13.6 ± 4.6 days after treatment. The rate of occurrence of erythema, itching, swelling, and pain/tenderness were 92.2%, 91.2%, 66.2%, and 48.5%, respectively. The occurrence of PLAR was significantly higher for great saphenous veins than for small saphenous veins (P < 0.001). Occurrences were more frequent in cases with a suprafascial great saphenous vein of length >10 cm than in cases with a subfascial great saphenous vein (P = 0.001). The proportion of patients who reported swelling decreased by more than half after the administration of oral antihistamine. The pain score on the 10th day also decreased significantly after the administration of antihistamine (P = 0.006). CONCLUSIONS: PLAR must be distinguished from classic phlebitis. We believe that PLAR is a type IV hypersensitivity reaction due to a foreign body, and in our experience, antihistamines or steroids are effective for the prevention and management of PLAR.

The alpha-gal story: lessons learned from connecting the dots.

Anaphylaxis is a severe allergic reaction that can be rapidly progressing and fatal, and therefore establishing its cause is pivotal to long-term risk management. Our recent work has identified a novel IgE antibody response to a mammalian oligosaccharide epitope, galactose-alpha-1,3-galactose (alpha-gal). IgE to alpha-gal has been associated with 2 distinct forms of anaphylaxis: (1) immediate-onset anaphylaxis during first exposure to intravenous cetuximab and (2) delayed-onset anaphylaxis 3 to 6 hours after ingestion of mammalian food products (eg, beef and pork). Results of our studies and those of others strongly suggest that tick bites are a cause, if not the only significant cause, of IgE antibody responses to alpha-gal in the southern, eastern, and central United States; Europe; Australia; and parts of Asia. Typical immune responses to carbohydrates are considered to be T-cell independent, whereas IgE antibody production is thought to involve sequential class-switching that requires input from T cells. Therefore, establishing the mechanism of the specific IgE antibody response to alpha-gal will be an important aspect to address as this area of research continues.

The alternative complement component factor B regulates UV-induced oedema, systemic suppression of contact and delayed hypersensitivity, and mast cell infiltration into the skin.

Ultraviolet (UV) wavelengths in sunlight are the prime cause of skin cancer in humans with both the UVA and UVB wavebands making a contribution to photocarcinogenesis. UV has many different biological effects on the skin that contribute to carcinogenesis, including suppression of adaptive immunity, sunburn and altering the migration of mast cells into and away from irradiated skin. Many molecular mechanisms have been identified as contributing to skin responses to UV. Recently, using gene set enrichment analysis of microarray data, we identified the alternative complement pathway with a central role for factor B (fB) in UVA-induced immunosuppression. In the current study we used mice genetically deficient in fB (fB-/- mice) to study the functional role of the alternative complement pathway in skin responses to UV. We found that fB is required for not only UVA but also UVB-induced immunosuppression and solar-simulated UV induction of the oedemal component of sunburn. Factor B-/- mice had a larger number of resident skin mast cells than control mice, but unlike the controls did not respond to UV by increasing mast cell infiltration into the skin. This study provides evidence for a function role for fB in skin responses to UV radiation. Factor B regulates UVA and UVB induced immunosuppression, UV induced oedema and mast cell infiltration into the skin. The alternative complement pathway is therefore an important regulator of skin responses to UV.

Granzyme B releases vascular endothelial growth factor from extracellular matrix and induces vascular permeability.

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.

Cannabidiol attenuates delayed-type hypersensitivity reactions via suppressing T-cell and macrophage reactivity.

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.

Exacerbation of delayed-type hypersensitivity responses in EBV-induced gene-3 (EBI-3)-deficient mice.

Epstein-Barr virus-induced gene-3 (EBI-3) associates with p28 to form interleukin-27 (IL-27) or with IL-12p35 to form IL-35. Both IL-27 and IL-35 have immunosuppressive functions and especially IL-35 has been implicated in the suppressive function of regulatory T cells (Treg). To address the role of EBI-3 in immune regulation, delayed-type hypersensitivity (DTH) responses were examined in EBI-3-deficient (EBI-3(-/-)) mice. EBI-3(-/-) mice developed deteriorated DTH responses as shown by the enhanced footpad swelling and augmented infiltration of inflammatory cells into the antigen-challenged footpads as compared with wild-type (WT) mice. While EBI-3-deficiency showed little effects on antigen-specific IFN-gamma production of lymph node cells, IL-17 production was drastically augmented in EBI-3(-/-) cells as compared with in WT cells. In addition, reduced IL-10 production was also evident in EBI-3(-/-) CD4(+) T cells. Interestingly, the development and suppressive function of Treg to inhibit effector T cell proliferation was not affected by EBI-3-deficiency. These data clearly demonstrated the immunosuppressive function of EBI-3 and provided complementary evidence that EBI-3 and EBI-3-containing cytokines might be taken into consideration as potential targets for some immune-related diseases.

Enhanced contact hypersensitivity by delayed T-helper 2 response in BALB/c mice.

T-helper (Th) 1/Th2 balance determines the direction of contact hypersensitivity (CHS). To clarify the immunopathogenesis of contact dermatitis, 2,4-dinitrofluorobenzene (DNFB)-induced CHS reaction was compared between the BALB/c and C57BL/6 mice. The two strains were sensitized with DNFB systemically and challenged with DNFB locally. The CHS reaction in BALB/c mice was intense compared with that in C57BL/6 mice at 24 and 48 hours post-DNFB challenge. The dermal lesions were characterized by infiltration of lymphocytes, eosinophils, neutrophils, and macrophages including CD4+ and CD8+ T cells, and interleukin (IL)-4-producing(+) and interferon (IFN)-gamma+ cells in BALB/c mice. In C57BL/6 mice, the composition of inflammatory cells was same as those in BALB/c mice except for eosinophils, CD4+ T cells, and IL-4+ cells. There was no increase in the number of mast cells in the two strains. Local and systemic productions of IL-4 and IFN-gamma in BALB/c mice were higher than those in C57BL/6 mice. Although blood IgE values increased in BALB/c mice, but not in C57BL/6 mice, at 48 hours postchallenge, its value was low. The delayed Th2-like response together with Th1-like response in BALB/c mice may induce strong CHS reaction compared with C57BL/6 mice, which may dominantly develop Th1-like reaction. Moreover, mast cell and IgE do not appear to be involved in delayed CHS.

Heparin allergy: delayed-type non-IgE-mediated allergic hypersensitivity to subcutaneous heparin injection.

Itching erythematous or eczematous plaques around injection sites are quite frequent side effects of heparin treatment and clinical symptoms of delayed-type non-IgE-mediated allergic hypersensitivity (DTH) to heparin. For diagnosis, intradermal, patch, and subcutaneous challenge tests with heparins are suitable. In most cases, changing the subcutaneous therapy from unfractionated to low molecular weight heparin or treatment with heparinoids does not provide improvement because of extensive cross-reactivity. Hirudin polypeptides, which exhibit a different chemical structure, are a safe therapeutic alternative for subcutaneous application, however. Importantly, despite DTH to subcutaneously injected heparins, most patients tolerate heparin intravenously. Moreover, in case of therapeutic necessity and DTH to heparins, the simple shift from subcutaneous to intravenous heparin administration without prior testing may be justified.

Rapid desensitization for hypersensitivity reactions to medications.

Drug desensitization is the induction of temporary clinical unresponsiveness to drug antigens to which patients have presented severe hypersensitivity reactions. It is typically achieved by gradual reintroduction of small doses of drug antigens at fixed time intervals, and it is aimed at providing increased safety and protection from side effects, including anaphylaxis. Delivery of full therapeutic doses is achieved during desensitization, allowing patients to receive firstline chemotherapy, antibiotics, or monoclonal antibodies, as well as other drugs such as insulin, aspirin, and iron. Desensitizations are high-risk interventions. Inhibition of cellular activation mechanisms occurs during drug desensitization, allowing for the protective clinical outcomes and lack of side effects in the majority of cases, but the cellular and molecular inhibitory mechanisms are incompletely understood. The indication for desensitization protocols can only be done by trained allergists and immunologists and should be implemented as standard of care because of their high success rates and outcomes-demonstrated safety profile.

Role of cytokines in mediating mechanical hypernociception in a model of delayed-type hypersensitivity in mice.

In the present study, we used the electronic version of the von Frey test to investigate the role of cytokines (TNF-alpha and IL-1beta) and chemokines (KC/CXCL-1) in the genesis of mechanical hypernociception during antigen-induced inflammation in mice. The nociceptive test consisted of evoking a hindpaw flexion reflex with a hand-held force transducer (electronic anesthesiometer) adapted with a 0.5 mm(2) polypropylene tip. The intraplantar administration of methylated bovine serum albumin (mBSA) in previously immunized (IM), but not in sham-immunized (SI) mice, induced mechanical hypernociception in a dose-dependent manner. Hypernociception induced by antigen was reduced in animals pretreated with IL-1ra and reparixin (a non-competitive allosteric inhibitor of CXCR2), and in TNF receptor type 1 deficient (TNFR1-/-) mice. Consistently, antigen challenge induced a time-dependent release of TNF-alpha, IL-1beta and KC/CXCL-1 in IM, but not in SI, mice. The increase in TNF-alpha levels preceded the increase in IL-1beta and KC/CXCL1. Antigen-induced release of IL-1beta and KC/CXCL1 was reduced in TNFR1-/- mice, and TNF-alpha-induced hypernociception was inhibited by IL-1ra and reparixin. Hypernociception induced by IL-1beta in immunized mice was inhibited by indomethacin, whereas KC/CXCL1-induced hypernociception was inhibited by indomethacin and guanethidine. Antigen-induced hypernociception was reduced by indomethacin and guanethidine and abolished by the two drugs combined. Together, these results suggest that inflammation associated with an adaptive immune response induces hypernociception that is mediated by an initial release of TNF-alpha, which triggers the subsequent release of IL-1beta and KC/CXCL1. The latter cytokines in turn stimulate the release of the direct-acting final mediators, prostanoids and sympathetic amines.

Mucosal tolerization to E-selectin protects against memory dysfunction and white matter damage in a vascular cognitive impairment model.

Vascular cognitive impairment (VCI) is the second most prevalent type of dementia in the world. The white matter damage that characterizes the common subcortical ischemic form of VCI can be modeled by ligating both common carotid arteries in the Wistar rat to induce protracted cerebral hypoperfusion. In this model, we find that repetitive intranasal administration of recombinant E-selectin to induce mucosal tolerance and to target immunomodulation to activating blood vessels potently suppresses both white matter (and possibly gray matter) damage and markers of vessel activation (tumor necrosis factor and E-selectin); it also preserves behavioral function in T-maze spontaneous alternation, T-maze spatial discrimination memory retention, and object recognition tests. Immunomodulation may be an effective novel strategy to prevent progression of VCI.

Demethylnobiletin inhibits delayed-type hypersensitivity reactions, human lymphocyte proliferation and cytokine production.

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.

Metalloproteinase inhibition has differential effects on alloimmunity, autoimmunity, and histopathology in the transplanted lung.

BACKGROUND: Upregulation of matrix metalloproteinases (MMPs) has been associated with chronic lung allograft rejection known as bronchiolitis obliterans syndrome. It has been suggested that MMP inhibition could prevent the rejection response. However, the effect of MMP inhibition on lung allograft rejection has not been reported. METHODS: Utilizing a rat model of lung transplantation, tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) were overexpressed by gene therapy in F344 rat lung allografts prior to transplantation into WKY recipient rats. Separately, WKY rats that received F344 lung allografts were treated systemically with COL-3, a global MMP inhibitor. RESULTS: TIMP-1 and TIMP-2 had differential effects on delayed type hypersensitivity (DTH) responses to donor antigens and type V collagen, an autoantigen involved in the rejection response. Neither TIMP-1 or TIMP-2 affected the onset of rejection pathology. COL-3 suppressed DTH responses to donor antigens and type V collagen, abrogated local production of tumor necrosis factor-alpha, and interleukin-1beta. Although it did not prevent rejection pathology, COL-3 (30 mg/kg) induced intragraft B cell hyperplasia suggestive of posttransplant proliferative disorder (PTLD). CONCLUSIONS: These data identify a complex role for MMPs and TIMPs in the immunopathogenesis of lung allograft rejection, and indicate their effects are not limited to matrix remodeling.

[Type IV of hypersensitivity and its subtypes]. / Reakcja alergiczna typu IV i jej podtypy.

Type IV of hypersensitivity reaction is usually manifested in the skin in different clinical pattern. According to traditional Gell and Coombs classification, the mechanism of IV type of allergic reaction has been associated with contact allergy with the activity of lymphocytes Th1 secreting interferon gamma. Now, this vision seems to be too simplified. In the last years there were publications, which can throw a new light on these complicated mechanisms leading to the development of the type IV of allergy, especially to drugs, nickel and other haptens and also can explain the differentiation of clinical pattern in respective patients. The skin symptoms in type IV of hypersensitivity are triggered by activation of specific T-cell CD4+ and CD8+. Immunohistochemical and functional analysis of reactive T-cell has shown that the delayed hypersensitivity reaction depends on the secreted cytokines. For example maculo-papular exanthema may be either triggered by Th1 or Th2 in nature and cytokines interferon gamma, tumor necrosis factor alfa or interleukin-4, 5 and 13. Bullous reactions (i.e. Stevens-Johnsons Syndrome or toxic epidermal necrolysis) are characterized by widespread keratinocyte apoptosis, a consequence of high CD8+ T-cell involvement and the molecular cytotoxicity of Fas, perforin and granzyme B. Pustular exanthema reactions are stimulated via the T-cell release of 11-8 and granulocyte-monocyte colony-stimulatig factor (GM-CSF). For the better understanding of these inflammatory cascades deleted type IV of hypersensitivity reactions have been re-classified into four main subtypes: 1. IVa with Th1 and monocyte directed and cytokines: IFNgamma, IL-1, IL-2, 2. IVb with Th2 and eosinophils directed and cytokines: L-5, IL-4, IL-13, 3. IVc with T CD8+ directed and cytokines: perforin, granzyme B, Fas Ligand, 4. IVd with T CD4+, CD8+ and neutrophil directed and cytokines: IL8, GM-CSF. Clinically delayed hypersensitivity eruptions are often an overlap of cytokine pathways, with one preferential reaction dominating the final picture. Type IVa and IVc play a role inthe mechanism of contact dermatitis, however type IV b in chronic asthma, chronic allergic rhinitis and maculo-papular exanthema with eosinophilia, type IV c in bullous reactions (i.e. Stevens-Johnsons Syndrome or toxic epidermal necrolysis), so type IV d in pustular exanthema reactions (i.g. AGEP - Acute Generalized Exanthematosus Pustule, Behcet disease). This different clinical pattern of allergic disease mainly including drug allergy to nickel and other haptens as well as chronic asthma and allergic rhinitis may be explained by above mechanisms. The study of different mechanisms of four subtypes of type IVof allergic reaction may be helpful in the differential diagnostics and in the treatment of allergic diseases.

Leukocyte-endothelial interactions via ICAM-1 are detrimental in polymicrobial sepsis.

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.

Abrogation of delayed type hypersensitivity response to Candida albicans produced by a molecular mimic of phosphorylated prolactin.

The effects of two major forms of prolactin (PRL) were examined on delayed type hypersensitivity (DTH) responses to Candida albicans. Unmodified PRL (U-PRL) had no effect on the DTH response, whereas a molecular mimic of phosphorylated PRL (S179D PRL) significantly inhibited immune responses to this robust antigen. This effect of S179D PRL was not accompanied by gross alterations in splenic T cell numbers, CD4/CD8 ratios, or T and B cell activation markers, but did produce a decrease in splenocyte apoptosis. Using gld animals, Fas ligand (FasL) was implicated in the suppressive effects of S179D PRL. Circulating IgG1 and IgG2 antibody levels were increased in response to treatment with both forms of PRL, but the effects of S179D PRL were most pronounced. Cytokine changes in the popliteal lymph nodes specific to S179D PRL treatment showed an inhibition of pro-inflammatory cytokines. In conclusion, mice treated with a molecular mimic of phosphorylated prolactin showed a profound inhibition of DTH responses to Candida correlating with an absence of GM-CSF, IL-4, and IL-13 production and a marked reduction in IL-12p70 synthesis.

Mycobacterial trehalose 6,6'-dimycolate preferentially induces type 1 helper T cell responses through signal transducer and activator of transcription 4 protein.

Mycobacterium tuberculosis is an intracellular pathogen of tuberculosis and its pathogenicity is related to the ability to escape killing by ingested macrophages and induce delayed-type hypersensitivity (DTH). A major component of the cell wall of M. tuberculosis is trehalose 6,6'-dimycolate (TDM), which has been implicated as a pathogenetic factor. The expression of DTH and cell-mediated immunity is dependent on the macrophage-cytokine-type 1 helper T (Th1) lymphocyte axis. Cytokines, interleukin-12 (IL-12) and interferon-gamma (IFN-gamma), play a critical role in the process and IL-12-activated signal transducer and activator of transcription (STAT) 4 is required for the development of fully functional Th1 cells. To clarify host responses to mycobacterial TDM, we have analyzed footpad reaction, histopathology and cytokine profile of experimental granulomatous lesions using STAT4-deficient mice. In the present study, we have demonstrated that mycobacterial TDM selectively induces the Th1 response through the STAT4 signaling pathway, because mice lacking STAT4 protein significantly reduced to develop DTH, hypersensitivity granulomas, and Th1 cytokine responses, when compared to BALB/c mice. These results shed light on the molecular pathogenesis of mycobacterial disease. Taken together with previous studies, TDM is a pleiotropic molecule against the host and participates in the pathogenesis.

Modulation of delayed-type hypersensitivity responses in hairless guinea pigs by peptides derived from enkephalin.

Although opioid peptides such as methionine (met)-enkephalin have been previously shown to enhance or suppress immune responses, few studies in animal models have addressed the immunomodulatory activity of their metabolic derivatives. Hairless (IAF/HA-HO) guinea pigs immunized with Freund's complete adjuvant containing Mycobacterium tuberculosis and repeatedly skin tested with purified protein derivative of tuberculin (PPD) display high levels of stable delayed-type hypersensitivity (DTH) to PPD. Met-enkephalin (YGGFM) and two of its metabolites (YGG, YG) enhanced and accelerated PPD-elicited DTH inflammatory reactions when injected together with elicitor in these animals. At 24 h, 5 x 10(-3) pmol met-enkephalin significantly enhanced DTH responses by 30% over PPD alone, while 5 x 10(-5) pmol of YGG and 5 x 10(-9) pmol of YG significantly enhanced these responses by 62 and 32%, respectively. At much higher doses (5 x 10(3) pmol), met-enkephalin and its metabolites significantly suppressed DTH reactions by 25-32%. Tyrosine and glycine had no effect on PPD-elicited DTH. All DTH reactions (control, enhanced, suppressed) displayed typical perivascular mononuclear cell infiltrates. We conclude that the immunoactivity of met-enkephalin resides in its first two amino acids and suggest that cleavage of enkephalin molecules to YG occurs in serum and/or on the cell surface.