TLR13 recognizes bacterial 23S rRNA devoid of erythromycin resistance-forming modification

Host protection from infection relies on the recognition of pathogens by innate pattern-recognition receptors such as Toll-like receptors (TLRs). Here, we show that the orphan receptor TLR13 in mice recognizes a conserved 23S ribosomal RNA (rRNA) sequence that is the binding site of macrolide, lincosamide, and streptogramin group (MLS) antibiotics (including erythromycin) in bacteria. Notably, 23S rRNA from clinical isolates of erythromycin-resistant Staphylococcus aureus and synthetic oligoribonucleotides carrying methylated adenosine or a guanosine mimicking a MLS resistance-causing modification failed to stimulate TLR13. Thus, our results reveal both a natural TLR13 ligand and specific mechanisms of antibiotic resistance as potent bacterial immune evasion strategy, avoiding recognition via TLR13.

Murine CD8α+ DCs and human BDCA3+ DCs produce large amounts of IFN-λ in response to poly IC and DNA viruses (154.6)

Dendritic cells (DCs) can be segregated into various subsets based on phenotypic and functional differences. Whereas plasmacytoid DCs are known for their type I interferon (IFN) producing capacity, conventional (c) DCs are better known for their roles in T cell homeostasis and priming. Among cDCs the CD8α+ subset is especially efficient in producing IL-12p70 and the induction of immunity against various pathogens and cancer. Here, we reveal a new hallmark function of murine CD8α+ cDCs and their human BDCA3+ counterparts, namely the production of large amounts of IFN-lambda (IFN-λ, also termed IL-28/29) upon stimulation with poly IC. IFN-lambdas are potent immunomodulatory and antiviral cytokines. We demonstrate that the production of IFN-λ upon poly IC injection in vivo depends on hematopoietic cells and the presence of toll-like receptor (TLR)3, interferon regulatory factor (IRF)3, IRF7, IFN-IR, Fms-related tyrosine kinase 3 ligand (FL) and IRF8 but not on myeloid differentiation factor 88 (MyD88), Rig like helicases or lymphocytes. Furthermore, we show that both CD8α+ cDCs and plasmacytoid DCs produce large amounts of IFN-λ in response to HSV-1 or parapoxvirus. Thus, IFN-λ production in response to poly IC is a novel hallmark function of mouse CD8α+ cDCs and their human equivalents.

Mouse CD8alpha+ DCs and human BDCA3+ DCs are major producers of IFN-lambda in response to poly IC

Polyinosinic:polycytidylic acid (poly IC), a double-stranded RNA, is an effective adjuvant in vivo. IFN-λs (also termed IL-28/29) are potent immunomodulatory and antiviral cytokines. We demonstrate that poly IC injection in vivo induces large amounts of IFN-λ, which depended on hematopoietic cells and the presence of TLR3 (Toll-like receptor 3), IRF3 (IFN regulatory factor 3), IRF7, IFN-I receptor, Fms-related tyrosine kinase 3 ligand (FL), and IRF8 but not on MyD88 (myeloid differentiation factor 88), Rig-like helicases, or lymphocytes. Upon poly IC injection in vivo, the IFN-λ production by splenocytes segregated with cells phenotypically resembling CD8α(+) conventional dendritic cells (DCs [cDCs]). In vitro experiments revealed that CD8α(+) cDCs were the major producers of IFN-λ in response to poly IC, whereas both CD8α(+) cDCs and plasmacytoid DCs produced large amounts of IFN-λ in response to HSV-1 or parapoxvirus. The nature of the stimulus and the cytokine milieu determined whether CD8α(+) cDCs produced IFN-λ or IL-12p70. Human DCs expressing BDCA3 (CD141), which is considered to be the human counterpart of murine CD8α(+) DCs, also produced large amounts of IFN-λ upon poly IC stimulation. Thus, IFN-λ production in response to poly IC is a novel function of mouse CD8α(+) cDCs and their human equivalents.

Immune requirements of post-exposure immunization with modified vaccinia Ankara of lethally infected mice

Current prophylactic vaccines work via the induction of B and T cell mediated memory that effectively control further replication of the pathogen after entry. In the case of therapeutic or post-exposure vaccinations the situation is far more complex, because the pathogen has time to establish itself in the host, start producing immune-inhibitory molecules and spread into distant organs. So far it is unclear which immune parameters have to be activated in order to thwart an existing lethal infection. Using the mousepox model, we investigated the immunological mechanisms responsible for a successful post-exposure immunization with modified vaccinia Ankara (MVA). In contrast to intranasal application of MVA, we found that intravenous immunization fully protected mice infected with ectromelia virus (ECTV) when applied three days after infection. Intravenous MVA immunization induced strong innate and adaptive immune responses in lethally infected mice. By using various gene-targeted and transgenic mouse strains we show that NK cells, CD4 T cells, CD8 T cells and antibodies are essential for the clearance of ECTV after post-exposure immunization. Post-exposure immunization with MVA is an effective measure in a murine model of human smallpox. MVA activates innate and adaptive immune parameters and only a combination thereof is able to purge ECTV from its host. These data not only provide a basis for therapeutic vaccinations in the case of the deliberate release of pathogenic poxviruses but possibly also for the treatment of chronic infections and cancer.

Quantitative proteomics reveals subset-specific viral recognition in dendritic cells

Dendritic cell (DC) populations consist of multiple subsets that are essential orchestrators of the immune system. Technological limitations have so far prevented systems-wide accurate proteome comparison of rare cell populations in vivo. Here, we used high-resolution mass spectrometry-based proteomics, combined with label-free quantitation algorithms, to determine the proteome of mouse splenic conventional and plasmacytoid DC subsets to a depth of 5,780 and 6,664 proteins, respectively. We found mutually exclusive expression of pattern recognition pathways not previously known to be different among conventional DC subsets. Our experiments assigned key viral recognition functions to be exclusively expressed in CD4(+) and double-negative DCs. The CD8alpha(+) DCs largely lack the receptors required to sense certain viruses in the cytoplasm. By avoiding activation via cytoplasmic receptors, including retinoic acid-inducible gene I, CD8alpha(+) DCs likely gain a window of opportunity to process and present viral antigens before activation-induced shutdown of antigen presentation pathways occurs.

Survival of lethal poxvirus infection in mice depends on TLR9, and therapeutic vaccination provides protection

Poxviruses such as the causative agent of smallpox have developed multiple strategies to suppress immune responses, including the suppression of DC activation. Since poxviruses are large DNA viruses, we hypothesized that their detection by DCs may involve the endosomal DNA recognition receptor TLR9. Indeed, we have shown here that DC recognition of ectromelia virus (ECTV), the causative agent of mousepox, completely depended on TLR9. The importance of TLR9 was highlighted by the fact that mice lacking TLR9 showed drastically increased susceptibility to infection with ECTV. In contrast, we found that the strongly attenuated poxvirus modified vaccinia virus Ankara (MVA) activated DCs by both TLR9-dependent and -independent pathways. We therefore tested whether we could use the broader induction of immune responses by MVA to protect mice from a lethal infection with ECTV. Indeed, MVA given at the same time as a lethal dose of ECTV protected mice from death. Importantly, MVA also rescued TLR9-deficient mice if administered 2 full days after an otherwise lethal infection with ECTV. Therefore, these data suggest an essential role for TLR9 in the defense against poxviruses. In addition, postexposure application of MVA may protect against lethal poxvirus infection.

Clearance of an immunosuppressive virus from the CNS coincides with immune reanimation and diversification

Once a virus infection establishes persistence in the central nervous system (CNS), it is especially difficult to eliminate from this specialized compartment. Therefore, it is of the utmost importance to fully understand scenarios during which a persisting virus is ultimately purged from the CNS by the adaptive immune system. Such a scenario can be found following infection of adult mice with an immunosuppressive variant of lymphocytic choriomeningitis virus (LCMV) referred to as clone 13. In this study we demonstrate that following intravenous inoculation, clone 13 rapidly infected peripheral tissues within one week, but more slowly inundated the entire brain parenchyma over the course of a month. During the establishment of persistence, we observed that genetically tagged LCMV-specific cytotoxic T lymphocytes (CTL) progressively lost function; however, the severity of this loss in the CNS was never as substantial as that observed in the periphery. One of the most impressive features of this model system is that the peripheral T cell response eventually regains functionality at ~60–80 days post-infection, and this was associated with a rapid decline in virus from the periphery. Coincident with this "reanimation phase" was a massive influx of CD4 T and B cells into the CNS and a dramatic reduction in viral distribution. In fact, olfactory bulb neurons served as the last refuge for the persisting virus, which was ultimately purged from the CNS within 200 days post-infection. These data indicate that a functionally revived immune response can prevail over a virus that establishes widespread presence both in the periphery and brain parenchyma, and that therapeutic enhancement of an existing response could serve as an effective means to thwart long term CNS persistence.

Memory T cells Require Costimulation and Dendritic Cell Migration to Purge an Established Persistent Viral Infection (47.7)

Adoptive immunotherapy relies on transfer of exogenously derived pathogen-specific (memory) T cells and is a highly successful approach to purge an established persistent viral infection. For example, administration of adoptive immunotherapy to mice persistently infected with lymphocytic choriomeningitis virus (LCMV) (carrier mice) results in systemic eradication of the virus, including noncytopathic clearance of persistently infected CNS neurons. By visualizing GFP-tagged LCMV-specific memory CD8+ T cells on brain reconstructions, it was revealed that cytotoxic lymphocytes (CTL) distributed throughout the CNS within 8 days after immunotherapy. Flow cytometric and microscopic analyses revealed that conventional dendritic cells arrived in the CNS concurrent with the memory CTL and induced anti-viral cytokine production (e.g., TNF-alpha). When adoptive immunotherapy was performed in carrier mice depleted of DCs or with memory T cells deficient in TNF-alpha, the adoptively administered memory T cells failed to purge the persistent infection. We further demonstrated by employing CTLA-4-Fc blockade and CCR2 deficient recipients that memory CTL rely on costimulation and DC migration, respectively, for optimal secondary expansion and efficient viral clearance. These studies underscore the importance of DC mobility and memory CTL-DC interactions in the clearance of a persistent viral infection.

Adoptive immunotherapy induces CNS dendritic cell recruitment and antigen presentation during clearance of a persistent viral infection

Given the global impact of persistent infections on the human population, it is of the utmost importance to devise strategies to noncytopathically purge tissues of infectious agents. The central nervous system (CNS) poses a unique challenge when considering such strategies, as it is an immunologically specialized compartment that contains a nonreplicative cell population. Administration of exogenously derived pathogen-specific memory T cells (referred to as adoptive immunotherapy) to mice burdened with a persistent lymphocytic choriomeningitis virus (LCMV) infection from birth results in eradication of the pathogen from all tissues, including the CNS. In this study, we sought mechanistic insights into this highly successful therapeutic approach. By monitoring the migration of traceable LCMV-specific memory CD8⁺ T cells after immunotherapy, it was revealed that cytotoxic T lymphocytes (CTLs) distributed widely throughout the CNS compartment early after immunotherapy, which resulted in a dramatic elevation in the activity of CNS antigen-presenting cells (APCs). Immunotherapy induced microglia activation as well as the recruitment of macrophages and dendritic cells (DCs) into the brain parenchyma. However, DCs emerged as the only CNS APC population capable of inducing memory CTLs to preferentially produce the antiviral cytokine tumor necrosis factor-α, a cytokine demonstrated to be required for successful immunotherapeutic clearance. DCs were also found to be an essential element of the immunotherapeutic process because in their absence, memory T cells failed to undergo secondary expansion, and viral clearance was not attained in the CNS. These experiments underscore the importance of DCs in the immunotherapeutic clearance of a persistent viral infection and suggest that strategies to elevate the activation/migration of DCs (especially within the CNS) may facilitate pathogen clearance.

Insufficient APC capacities of dendritic cells in gene gun-mediated DNA vaccination

Gene gun-mediated DNA immunization is a powerful mode of vaccination against infectious diseases and tumors. Many studies have identified dendritic cells (DC) as the central players in inducing immunity upon biolistic DNA vaccination; however, none of these studies directly quantify DC-mediated responses in comparison with immunity triggered by all Ag- and MHC-expressing cells. In this study we use two different approaches to decipher the relative role of DC vs other cell types in gene gun-induced immunity. First, we directly compared the immunization efficacy of different DNA constructs, which allow Ag expression ubiquitously (CMV promoter) or specifically in DC (CD11c promoter) and would encode either for soluble or membrane bound forms of Ag. Second, we immunized transgenic mice in which only DC can present MHC-restricted Ag, and directly compared the magnitudes of CTL activation with those obtained in wild-type mice. Surprisingly, our combined data suggest that, although DC-specific Ag expression is sufficient to induce humoral responses, DC alone cannot trigger optimal CD4 and CD8 T cell responses upon gene gun vaccination. Therefore, we conclude that DC alone are insufficient to mediate optimal induction of T cell immunity upon gene gun DNA vaccination and that broad Ag expression rather than DC-restricted approaches are necessary for induction of complete immune responses.

Reduced immune responses after vaccination with a recombinant herpes simplex virus type 1 vector in the presence of antiviral immunity

Due to the continuous need for new vaccines, viral vaccine vectors have become increasingly attractive. In particular, herpes simplex virus type 1 (HSV-1)-based vectors offer many advantages, such as broad cellular tropism, large DNA-packaging capacity and the induction of pro-inflammatory responses. However, despite promising results obtained with HSV-1-derived vectors, the question of whether pre-existing virus-specific host immunity affects vaccine efficacy remains controversial. For this reason, the influence of pre-existing HSV-1-specific immunity on the immune response induced with a replication-defective, recombinant HSV-1 vaccine was investigated in vivo. It was shown that humoral as well as cellular immune responses against a model antigen encoded by the vaccine were strongly diminished in HSV-1-seropositive mice. This inhibition could be observed in mice infected with wild-type HSV-1 or with a replication-defective vector. Although these data clearly indicate that pre-existing antiviral host immunity impairs the efficacy of HSV-1-derived vaccine vectors, they also show that vaccination under these constraints might still be feasible.

Protection from bacterial infection by a single vaccination with replication-deficient mutant herpes simplex virus type 1

Adaptive immune responses in which CD8(+) T cells recognize pathogen-derived peptides in the context of major histocompatibility complex class I molecules play a major role in the host defense against infection with intracellular pathogens. Cells infected with intracellular bacteria such as Listeria monocytogenes, Salmonella enterica serovar Typhimurium, or Mycobacterium tuberculosis are directly lysed by cytotoxic CD8(+) T cells. For this reason, current vaccines for intracellular pathogens, such as subunit vaccines or viable bacterial vaccines, aim to generate robust cytotoxic T-cell responses. In order to investigate the capacity of a herpes simplex virus type 1 (HSV-1) vector to induce strong cytotoxic effector cell responses and protection from infection with intracellular pathogens, we developed a replication-deficient, recombinant HSV-1 (rHSV-1) vaccine. We demonstrate in side-by-side comparison with DNA vaccination that rHSV-1 vaccination induces very strong CD8(+) effector T-cell responses. While both vaccines provided protection from infection with L. monocytogenes at low, but lethal doses, only rHSV-1 vaccines could protect from higher infectious doses; HSV-1 induced potent memory cytotoxic T lymphocytes that, upon challenge by pathogens, efficiently protected the animals. Despite the stimulation of relatively low humoral and CD4-T-cell responses, rHSV-1 vectors are strong candidates for future vaccine strategies that confer efficient protection from subsequent infection with intracellular bacteria.

Radioimmunodetection of neuroblastoma cells with I-131-radiolabelled antibodies

The murine anti-neuroblastoma monoclonal antibodies 15/7 and 19/1/4 should be tested for specific radiolocalization of neuroblastoma by immunoscintigraphic imaging of this tumour growing in mice. Radioiodination of both antibodies was done by chloramine-T method resulted in an immunoreactivity of 75%. The calculated specific activity varied from 51.1 to 126.2 kBq/microgram IgG. In each case, about 500 kBq of labeled antibodies were intraperitoneally injected into human neuroblastoma (SK-N-MC, SK-PN-DW and IMR 5) xenografted severe complete immunodeficient (SCID) mice. Whole-body scintigraphy was performed daily by a scintiscanner to localize the tumour site. After last scanning principal organs were removed and their I-131-uptake was determined by measuring the impulse rate. The best scintigrams were done with I-131-19/1/4 at the second day after antibody injection. Radioconjugates were accumulated at highest in the tumour at the third day after application of 15/7 and 19/1/4 with a tumour uptake of 0.4 and 2.2 per cent of injected dose per gram (%ID/g), respectively. The 15/7-moAbs was accumulated approximately 9-fold higher in the SK-N-MC and SK-PN-DW grafts than in principal organs, whereas the tumour/non-tumour-ratio of the 19/1/4 moAb was 3:1. The results indicate the efficacy of these two neuroblastoma antibodies in radiolabelling and their usefulness for tumour imaging of neuroblastoma engrafted SCID-mice.

Diacetyl-splenopentin (BCH 069) did not affect the concentrations of various hormones in men

We investigated the effect of BCH 069 (similar structure as thymopentin) on concentrations of hormones of the hypophysis, adrenals, gonads and thyroid glands in men after a therapy period of 4 or 6 weeks. No significant effects of BCH 069 three times weekly 50 mg s.c. for 4 weeks or i.v. for 6 weeks on serum concentrations of prolactin, LH, TSH, cortisol, testosterone, progesterone, estradiol and ETR were observed.

[Severe oligozoospermia as a sequela to partial obstruction of the seminiferous tubules]

Arguments for the presence of a partial obstruction as cause of severe oligozoospermia may result from following findings. 1. The frequency of normal FSH values in oligozoospermia (44.9%) do not differ significantly from cases with azoospermia (50%). 2. Including a quantitative analysis of testicular morphology 5 out of 63 patients (7.9%) suffering from severe oligozoospermia show a normal spermatogenesis. 3. The frequency of this constellation in our material including severe oligozoospermia, normal testicular volume, normal FSH value, and normal spermatogenesis agree with few findings in the literature. The number of etiological factors of partial obstruction require also invasive diagnostical procedures like vas deferens radiography and surgical exploration.

[Studies of the relevance of the tumor marker neopterin for therapeutic decisions and follow-up of breast cancer]

The value of serum neopterin as tumour marker was verified on 104 breast cancer patients. Based on the results, neopterin cannot be recommended either for deciding treatment after primary therapy or for monitoring of breast cancer.

[Testicular function in obstructive azoospermia]

The normal histological findings of the testicles with simultaneous azoospermia according to the former opinion renders greatly probable an obstruction of the seminal ducts. The reversed case of an ascertained obstruction, however, must not necessarily contain also normal histological structures or normal hormone tests. In the obstruction syndrome in 6 out of 23 cases we find changes in the diameter of the tubule, reductions of the spermatogenesis and changes at the interstice. Imprint-cytologically an increase of pathological spermatides at the cost of normal cell developments is shown. According to this the FSH-values are slightly but statistically significantly increased. LH, PRL and testosterone are found within the normal. For the diagnostic delimitation of the obstruction syndrome from a production azoospermia according to these findings the performance of a biopsy of the testicles with histological evaluation and the determination of the FSH-value. The relatively discrete tubular changes alone cannot be used for the explanation of the discrepancy between anatomical and functional results of the operative reconstruction of the seminal ducts.

[Prolactin and male fertility]

On 68 selected patients with disturbances of the potentia generandi et/sive coeundi (25 males with healthy metabolism and 43 males with diabetes) as well as 14 control persons PRL, LH, FSH, testosterone and oestradiol were determined radioimmunologically and the results were ascribed to sexological, clinical, spermatological and testo-histological findings. A statistically secure correlation was found between PRL values and disturbance of the libido as well as the presence of a gynaecomasty. PRL did not correlate with the spermatological variables volume of ejaculate, relative and absolute number of spermatozoa and motility. PRL did also not correlate with the testohistological findings. A relation between PRL and the peptide hormones LH and FSH as well as the steroid hormones testosterone and oestradiol could not be ascertained. Therefore the diagnostic values of a PRL determination is much limited; the pertinency of a hyperprolactinaemia may be increased by the proof of the symptoms reduction of libido and gynaecomasty with simultaneous disturbance of fertility. In our opinion the definition of hyperprolactinaemia needs revision, since at only determination of the basal value of more than 800 mU/l no more frequently pathologically andrological findings are to be observed than below 200 mU/l.

Influence of hemoperfusion with XAD-4 resin on the concentration of biologic constituents in the blood

13 patients, who had been subjected to hemoperfusion with Amberlite XAD-4 resin (Haemoresin, Fa. Braun), because of acute intoxications, were examined for the adsorption of bioactive material from the blood. A mean treatment period of four hours at a blood flow rate of 200 ml/min. resulted in a marked thrombocyte decrease by 43% and changes in the concentrations of proteins, complement components C3 and C4 (16-26%) triglycerides (33%), aldosterone (33%) and testosterone (20%). Low molecular weight substances and electrolytes, however, were only slightly or not affected. Thus hemoperfusion system with its poor biocompatibility and inability to remove BUN, electrolytes and water is only suitable for short-term treatment and cannot be used without detailed control of possible side effects and perhaps substitution for treatment of chronic renal or hepatic failure. Hemoperfusion has proved an efficient method of treating various exogenous intoxications. The adsorption of biologically active material from the blood constitutes several side effects which contraindicate long-term treatment, above all of endogenous intoxications such as chronic renal failure and hepatic failure. With the type of adsorber used - various charcoal preparations, resins etc. such as uncoated material or coated with different substances - these side effects vary and have not yet been investigated in a systematic, comparative and comprehensive way. The present investigations are meant to check the adsorption behaviour of Amberlite XAD-4 Resin in vivo towards some selected blood constituents and the influence of hemoperfusion on the concentrations.

[The effect of hemoperfusion with XAD-4 resin on biological constituents of the blood]

13 patients who had undergone a haemoperfusion therapy with Amberlite XAD-4 resin (Haemoresin, Braun, F.R.G.) because of acute intoxication were examined for adsorption of biological material from the blood. Treatment lasting on average 4 hours at a blood-circulation rate of 200 ml/min resulted in a 43% reduction of thrombocytes and in changes in the concentrations of proteins, complement factors, triglycerides, aldosterone and testosterone. Low-molecular substances and electrolytes were however, except for sodium, only slightly influenced. Thus this haemoperfusion system is only suitable for shortterm application and cannot be used without substitution for chronic treatment of terminal renal insufficiency.

[Androgen regulation in patients with diabetic retinopathy]

In 21 male diabetics (juvenile onset diabetes) with diabetic retinopathy and 13 patients without this condition, the HCG and the LH-RH stimulation tests were performed and the results compared to those of 20 persons with normal metabolism and full vision. The findings can be interpreted as hypothalamic hypophysogonadal dysregulation in case of lowered basal testosterone, significantly inverse correlation to the relative responsiveness of Leydig's cells, lacking correlation between LH and testosterone as well as normal LH-RH test. Differences between patients with and without retinopathy were not detectable.

Effects of an intranasally administered low dose progestogen on the pituitary and gonadal functions

This study was undertaken to investigate possible mechanisms of action of a daily intranasally administered low dose of norethisterone acetate (40 microgram) in regularly menstruating young women. Besides measurement of basal body temperature, serum concentrations of FSH, LH, estradiol and progesterone were determined over one treatment cycle. An endometrial biopsy was taken on day 27 or 28 of the cycle. In spite of a considerable individual variation in the respective values the following effects could be observed: In 8 of 9 subjects the midcycle LH peak was abolished, while basal FSH and LH levels remained within the control range of the follicular and luteal phases. A variable reduction of progesterone levels below the range indicative of a normal luteal phase function suggested a tendency to atypical corpus luteum formation. In 8 of 9 endometrial biopsies, however, secretory transformation could be found.

Induction of pituitary tumours and hyperprolactinemia in female rats by estrogens. The effect of apomorphine, reserpine and L-dopa

Prolonged estrogen treatment induced an enlargement of the anterior pituitary gland and finally resulted in irreversible pituitary tumours. Using continuous estrogen delivery [subcutaneous (s.c.) cholesterol-estrogen implants], the effects of ethinyl estradiol and the likewise synthetic estrogens STS 153 and STS 456 have been studied with or without concomitant administration of a progestogen without anti-estrogenic activities (STS 557). There was a dose-dependent prolactin cell-stimulating effect of all these estrogens. Ethinyl estradiol (EE2) had the most marked effect followed by STS 456 which coincides with the relative uterotrophic activity found in rats and mice. The elevated serum prolactin levels in rats with an EE2 implant for 6 months could be reduced slightly but not significantly by apomorphine and reserpine at a daily dose of 100 micrograms/animal and 5 micrograms/animal, respectively. Daily administration of 300 micrograms L-dopa led to a slight but insignificant increase of serum prolactin. The high pituitary weight and serum prolactin levels induced by long-term EE2 treatment were partially reversible after implant withdrawal.