Analysis of Risk Factors for a Low Immune Response to Messenger RNA COVID-19 Vaccine in Kidney Transplant Recipients and Differences Between Second and Third Dose

BACKGROUND

The efficacy of the response to SARS-CoV-2 vaccination in kidney transplant recipients is low. The aim of our study was to evaluate the risk factors correlated with the low antibody response and whether there was an improvement between the second and the third dose.

METHODS

A prospective study was conducted on 176 kidney transplant recipients who received the second and the third dose of the anti-SARS-CoV-2 mRNA Comirnaty vaccine. We evaluated the seroconversion process after administration of the second and the third dose and assessed a possible correlation with age, time between transplant and vaccination, and type of immunosuppressive therapy.

RESULTS

A total of 98 of the 176 patients (55.7%) responded positively after the inoculation of the second dose and according to the multivariable logistic regression analysis the lack of seroconversion was independently associated with patient age ≥60 (P = .025; odds ratio [OR], 2.094), time since transplant of 1 to 3 months (P = .032; OR, 2.118), and triple therapy (P = .044; OR, 2.327). After the vaccine third dose, the seroconversion increased to 62.5%, and it was negatively influenced by calcineurin inhibitor use (12/21, 57.1% vs 71/78, 91.0%, P = .0006) and triple therapy (13/21, 61.9% vs 72/78, 92.3%, P = .0014). The median of antispike antibody response significantly increased from 18.5 IU/mL after the second dose to 316.9 IU after the third dose (P < .0001).

CONCLUSIONS

We demonstrated a correlation between older age and shorter distance from the transplant and triple immunosuppressive therapy with the lack of seroconversion. We noticed a significant improvement in antibody response by a third dose of messenger RNA vaccine.

Volatiloma analyses of four South African Helichrysum spp. grown in Italy

The volatiloma of four Helichrysum species (H. anomalum, H reflexum, H. retortum and H. rugulosum) was analysed here for the first time by GC-MS for a chemotaxonomic contribution to this genus. Sesquiterpene hydrocarbons (SHs) prevailed in the aroma profile (VOCs) of H. reflexum, H. rugulosum and H. anomalum (74.7%, 93.6% and 41.6%, respectively), even though the main compounds were different (β-caryophyllene, α-humulene and α-copaene, respectively). The VOCs of H. retortum showed a high percentage of aliphatic hydrocarbons (NTs, 77.7%) mainly represented by octyl ether. The essential oil composition of each of H. rugulosum and H. retortum followed the same trend as VOCs related to the main class (SHs and NTs, respectively). In H. reflexum EO, the SHs were replaced by oxygenated sesquiterpenes (OS, 49.0%) with caryophyllene oxide as the main compound, while in H. anomalum the SHs were swapped in NTs (37.3%).

Helichrysum araxinum Takht. ex Kirp. grown in Italy: volatiloma composition and in vitro antimicrobial activity

In the present work the composition of biogenic volatile organic compounds (BVOCs) and the essential oil (EO) of Helichrysum araxinum Takht. ex Kirp. aerial parts, together with the antimicrobial activity, were investigated. The results showed the prevalence of sesquiterpene hydrocarbons in both spontaneous emissions as well as in the EO. The main compounds of BVOCs were γ-curcumene (10.7%), γ-muurolene (9.2%), and β-selinene (8.5%). This latter constituent also showed a similar amount in the EO and represented the most abundant compounds together with α-selinene (8.0%). It is Interesting to note the same percentage of monoterpene hydrocarbons (MHs) in both the aroma profile and the EO (18.0%) with the same most abundant compounds: β-pinene (6.3% in BVOCs vs. 5.1% in EO, respectively) and limonene (4.5% in VOCs vs. 4.9% in EO, respectively). With regard to the antimycotic activity, the EO showed to be inactive against the tested strains, while a moderate antibacterial activity was shown against Staphylococcus isolates.

Volatiles and Antifungal-Antibacterial-Antiviral Activity of South African Salvia spp. Essential Oils Cultivated in Uniform Conditions

Spontaneous emissions of S. dentata Aiton and S. scabra Thunb., as well as the essential oil (EO) composition of the cited species, together with S. aurea L., were investigated. The chemical profile of the first two species is reported here for the first time. Moreover, in vitro tests were performed to evaluate the antifungal activity of these EOs on Trichophyton mentagrophytes, Microsporum canis, Aspergillus flavus, Aspergillus niger, and Fusarium solani. Secondly, the EO antibacterial activity against Escherichia coli, Staphylococcus aureus, and Staphylococcus pseudointermedius was examined, and their antiviral efficacy against the H1N1 influenza virus was assessed. Leaf volatile organic compounds (VOCs), as well as the EOs obtained from the arial part of Salvia scabra, were characterized by a high percentage of sesquiterpene hydrocarbons (97.8% and 76.6%, respectively), mostly represented by an equal amount of germacrene D (32.8% and 32.7%, respectively). Both leaf and flower spontaneous emissions of S. dentata, as well as the EO composition, showed a prevalence of monoterpenes divided into a more or less equal amount of hydrocarbon and oxygenated compounds. Interestingly, its EO had a non-negligible percentage of oxygenated sesquiterpenes (29.5%). S. aurea EO, on the contrary, was rich in sesquiterpenes, both hydrocarbons and oxygenated compounds (41.5% and 33.5%, respectively). S. dentata EO showed good efficacy (Minimal Inhibitory Concentration (MIC): 0.5%) against M. canis. The tested EOs were not active against E. coli and S. aureus, whereas a low inhibition of S. dentata EO was observed on S. pseudointermedius (MIC = 10%). Once again, S. dentata EO showed a very good H1N1 inhibition; contrariwise, S. aurea EO was completely inactive against this virus. The low quantity of S. scabra EO made it impossible to test its biological activity. S. dentata EO exhibited interesting new perspectives for medicinal and industrial uses.

Salvia Spp. Essential Oils against the Arboviruses Vector Aedes albopictus (Diptera: Culicidae): Bioactivity, Composition, and Sensorial Profile-Stage 1

Mosquito-borne arboviruses diseases cause a substantial public health burden within their expanding range. To date, their control relies on synthetic insecticides and repellents aimed to control the competent mosquito vectors. However, their use is hampered by their high economic, environmental, and human health impacts. Natural products may represent a valid eco-friendly alternative to chemical pesticides to control mosquitoes, and mosquito-borne parasitic diseases. The aim of this work was to combine the chemical and sensorial profiles with the bioactivity data of Salvia spp. essential oils (EOs) to select the most suitable EO to be used as a repellent and insecticide against the invasive mosquito Aedes albopictus (Diptera: Culicidae), vector of pathogens and parasites, and to describe the EOs smell profile. To do this, the EOs of four Salvia species, namely S. dolomitica, S. dorisiana, S. sclarea, and S. somalensis were extracted, chemically analyzed and tested for their bioactivity as larvicides and repellents against Ae. albopictus. Then, the smell profiles of the EOs were described by a panel of assessors. The LC₅₀ of the EOs ranged from 71.08 to 559.77 μL L⁻¹ for S. dorisiana and S. sclarea, respectively. S. sclarea EO showed the highest repellence among the tested EOs against Ae. albopictus females (RD₉₅ = 12.65 nL cm⁻²), while the most long-lasting, at the dose of 20 nL cm⁻², was S. dorisiana (Complete Protection Time = 43.28 ± 3.43 min). S. sclarea EO showed the best smell profile, while S. dolomitica EO the worst one with a high number of off-flavors. Overall, all the EOs, with the exception of the S. dolomitica one, were indicated as suitable for “environmental protection”, while S. dorisiana and S. sclarea were indicated as suitable also for “Body care”.

Volatilome Analyses and In Vitro Antimicrobial Activity of the Essential Oils from Five South African Helichrysum Species

Helichrysum genus was used in folk South African medicine to treat various human disorders. As a part of our on-going research addressing the exploitation of South African plants belonging to this genus, five species were investigated for their volatile and antimicrobial activities. The volatile organic compounds (VOCs) and the essential oils (EOs) were analysed by gas chromatography mass spectrometry (GC-MS). Microdilution was the method used for assessing both antimycotic and antibacterial activities, which was also tested by Kirby-Bauer agar disc diffusion. Total monoterpenes (TMs) dominated the VOCs of four species (H. trilineatum (70.6%), H. edwardsii (79.3%), H. cooperi (84.5%), and H. pandurifolium (57.0%)). H. cooperi and H. edwardsii EOs showed the predominance of TMs (68.2% and 84.5%, respectively), while H. pandurifolium and H. trilineatum EOs were characterized by the prevalence of TSs (86.5% and 43.6%, respectively). H. odoratissimum EO evidenced a similar amount of both TMs (49.5%) and TSs (46.4%). Microsporum canis was more sensitive to these EOs. The lowest minimum inhibitory concentration (MIC) was observed with H. pandurifolium and H. edwardsii EOs (0.25%). H. pandurifolium and H. trilineatum had a good effect on Staphylococcus aureus (MIC 5%). These findings open new perspectives for the exploitation of these natural compounds for application in cosmetics and pharmaceutics.

High throughput measure of diversity in cytoplasmic and nuclear traits for unravelling geographic distribution of rosemary

In the present work, variability of both cytoplasmic and nuclear microsatellite traits was investigated with the aim of characterizing a set of rosemary germplasm resources (Salvia rosmarinus). Most of the materials were collected in Italy and France. High-resolution melting curves were compared each other computing their Euclidean distances and estimating the differences within their principal component as a measure of genetic diversity. Mantel correlation results combined to linear discriminant analysis allowed examined populations to be divided in four principal groups corresponding to four geographic areas, with few interesting and discussed exceptions. As rosemary propagates by seeds coming from insect mediated pollination, steady wild populations can be expected to be in panmictic equilibrium. Gained results confirmed and extended precedent characterization of rosemary genotypes and are compatible with the distribution of other Mediterranean species, as well as with the presence of a glacial refugium in the north-east area of Sardinia previously described. As the officinal use of this aromatic shrub is spreading, characterization and conservation of wild Mediterranean germplasm is gaining strategic importance. A core collection of 100 genotypes was pointed out as suitable for a cheaper biodiversity ex situ preservation as well as for subsequent metabolic and linkage disequilibrium analyses.

Antioxidant Activity of Several Essential Oils from Different Rosmarinus officinalis Cultivars Grown in Sanremo (Italy)

The evaluation of the essential oil (EO) profile of several cultivars of Rosmarinus officinalis, usually not used for food, and the assessment of their antioxidant activity as potential sources of natural antioxidants were studied in this work. Five different cultivars of Rosmarinus officinalis: R. officinalis ‘Alba'; R. officinalis ‘Blue Rain'; R. officinalis ‘Corsican Blue'; R. officinalis ‘Israeli'; R. officinalis ‘Majorca Pink’ and one hybrid of rosemary, Rosmarinus x lavandulaceus Noë, cultivated at CREA Sanremo (Italy), were hydrodistilled separately and the obtained EOs were analysed by GC-MS. Monoterpenes predominated in all the EO profiles but oxygenated monoterpenes were the most abundant constituents in R. officinalis ‘Blue Rain’, R. officinalis ‘Corsican Blue’, R. officinalis ‘Israeli’ and R. officinalis ‘Majorca Pink’. R. x lavandulaceus Noë and R. officinalis ‘Alba’ showed percentages of monoterpene hydrocarbons and oxygenated monoterpenes very similar. α-pinene, camphene, 1,8-cineole, camphor, borneol, verbenone, isobornyl acetate and β-caryophyllene were the main constituents present in all the plant cultivars, even though in different percentages. Myrcene predominate in R. officinalis ‘Alba’ (30.3 %), 1,8 cineol in R. officinalis ‘Blue Rain’ and R. officinalis ‘Israeli’ (21.9% and 26.4%, respectively), while camphor was the main constituent in R. officinalis ‘Majorca Pink’ (42.5%) and in R. x lavandulaceus (24.2%). R. officinalis ‘Corsican Blue’ showed similar amount of the three main components, verbenone, camphor and isobornyl acetate (18.5% >18.2% >15.4%, respectively). All the EOs were also tested for their antioxidant activity using the ferric reducing antioxidant power (FRAP) method and the stable radical DPPH. R. x lavandulaceus Noë showed the highest antioxidant activity, two folds more than that observed in R. officinalis ‘Israeli’.

Essential Oil Composition and Volatile Profile of Seven Helichrysum Species Grown in Italy

Helichrysum genus consists of about 600 species widespread throughout the world, especially in South Africa and in the Mediterranean area. In this study the aroma profile (HS-SPME) and the EO compositions of seven Helichrysum species (H. cymosum, H. odoratissimum, H. petiolare, H. fontanesii, H. saxatile, H. sanguineum, and H. tenax) were evaluated. All the plants were grown in Italy under the same growth conditions. The volatile constituents, particularly monoterpenes, depended by the plant's genotype and ecological adaptation. This study represents the first headspace evaluation on the selected plants and the results evidenced that monoterpenes represented the main class of constituents in five of the seven species analysed (from 59.2% to 95.0%). The higher content in sesquiterpene hydrocarbons was observed in the Mediterranean species of H. sanguineum (68.0%). Only H. saxatile showed relative similar abundance of monoterpenes and sesquiterpene hydrocarbons. The essential oil composition of the majority of examined species are characterised by high percentage of sesquiterpenes (especially β-caryophyllene and δ-cadinene) ranging from 51.3% to 92.0%, except for H. cymosum, H. tenax, and H. sanguineum leaves where monoterpenes predominated (from 51.7% to 74.7%).

Aroma Profile and Essential Oil Composition of Helichrysum species

Essential oils and volatile emission from leaves and flowers of three Helichrysum species ( H. arenarium, H. nudifolium, H. graveolens) were analysed by GC-MS and SPME analysis. A total of 112 components were identified in the EOs representing 92.3–99.9% of the whole oil composition, while 109 constituents were identified in the spontaneous volatile emission accounted for 78.7–98.8% of the total volatile organic compounds (VOCs). Sesquiterpenes represented the main class of constituents in the EOs of the majority studied species. β-caryophyllene was the key compound of H. arenarium and H. nudifolium leaves, even though ( E)-2-hexenal showed high percentage in H. arenarium leaves. H. graveolens EO showed a good amount of diterpenes (cembrene and beyerene), absent in the other species. SPME analyses were carried out for the first time to complete the chemotaxonomic investigation on the volatile organic constituents of these plants.

Aroma Profile and Essential Oil Composition of Helichrysum species

Essential oils and volatile emission from leaves and flowers of three Helichrysum species ( H. arenarium, H. nudifolium, H. graveolens) were analysed by GC-MS and SPME analysis. A total of 112 components were identified in the EOs representing 92.3–99.9% of the whole oil composition, while 109 constituents were identified in the spontaneous volatile emission accounted for 78.7–98.8% of the total volatile organic compounds (VOCs). Sesquiterpenes represented the main class of constituents in the EOs of the majority studied species. β-caryophyllene was the key compound of H. arenarium and H. nudifolium leaves, even though ( E)-2-hexenal showed high percentage in H. arenarium leaves. H. graveolens EO showed a good amount of diterpenes (cembrene and beyerene), absent in the other species. SPME analyses were carried out for the first time to complete the chemotaxonomic investigation on the volatile organic constituents of these plants.

Oxygen-ozone in Orthopaedics: EPR Detection of Hydroxyl Free Radicals in Ozone-Treated “Nucleus Pulposus” Material

The direct and indirect application of oxygen-ozone in several orthopaedic affections was briefly reviewed, trying to understand possible mechanisms of action explaining the surprisingly good results and no toxicity. Moreover, by using EPR spin trapping technique with DEPMPO the generation of free radicals by treating human “nucleus pulposus” material with oxygen-ozone (O2-O3) was investigated. The DEPMPO spin adduct of hydroxyl radical (DEPMPO-OH) was detected. The presence of ·OH even at a very low ozone concentration (5 μg/mL) may explain why this material undergoes to a progressive breakdown with re-absorption and consequent disappearance of a hernial disk. Thus the intradiscal insufflation of a minute volume of O2-O3 may represent a new efficient, inexpensive and atoxic chemionucleolytic approach.

Genetic Predisposition to Rheumatoid Arthritis in a Tuscan (Italy) Ancient Human Remain

Rheumatoid arthritis (RA) is currently believed to have originated in America, and after the discovery of this continent in 1492, to have been exported to the Old World. We evaluated the genetic predisposition to RA in the “Braids Lady” from Arezzo (Italy), a partially mummified woman's body dating back to the end of 1500 AD which presents the anatomical and pathological features of this disease. The study of the polymorphic HLA-DRB1 locus, which includes alleles strongly associated with RA onset, has received much attention over recent years, especially the loci codifying for the DR1 and DR4 antigens, widely represented in the Mediterranean population, and for DR14, widespread among Native Americans. Molecular analysis was performed on extracts of DNA from the mummy, firstly from histological bone sections and then from the whole bone. Two different HLA typing techniques, PCR-sequence-specific oligonucleotides (PCR-SSO) and PCR-sequence-specific primers (PCR-SSP), were employed to identify HLA-DRB alleles. Both genotyping methods showed that the “Braids Lady” carried the DRB1*0101 allele, the serological equivalent of the DR1 antigen. Although the possession of RA risk factor genes cannot be considered a diagnostic marker, the positive result of the Italian mummy for DRB1*0101 and the RA features present, support the idea that this pathology was present in the Old World from at least the mid-16th century. A pathogenetic hypothesis of RA which might well explain its worldwide diffusion is the “molecular mimicry”, resulting from a cross-reactive antibody response between certain microbial antigens and shared epitopes of specific HLA-DR1, DR4 and DR14 susceptibility alleles, the frequency of which varies among different ethnic groups.

Influence of cytotoxic T-lymphocyte antigen-4 polymorphisms on acute rejection onset of cadaveric renal transplants

We retrospectively examined in cadaveric renal transplants the association between acute rejection episodes (ARE) and single nucleotide polymorphisms (SNPs) localized in the cytotoxic T-lymphocyte antigen (CTLA)-4 promoter, -1147T/C and -318C/T, in exon 1 +49A/G and within the 3' untranslated region (UTR) CT60G/A. Each one of these SNPs may influence the cell surface expression of the CTLA-4 molecule. Seventy-two cadaveric renal transplant recipients with at least 6 month's follow-up were genotyped for CTLA-4 dimorphisms using direct sequencing of specific polymerase chain reaction products. Allele frequencies in both groups of patients with or without acute rejection (ARE and non-ARE) did not show significant differences in various nucleotide positions. At the level of genotype frequency we first noted a positive association to acute rejection of G/G genotypes (ARE af = 14.7%, non-ARE af = 5.9%) for the +49 (cod. 17), which was associated with decreased expression of the CTLA-4 full-length molecule. In contrast, the AG genotype seemed to be protective (61.8% vs 32.4%, P = .028; odds ratio [OR] = 0.2961). Regarding the CT60G/A dimorphism, noteworthy was the identification of a significantly higher incidence of CT60 A/A genotype in ARE compared with non-ARE group (29.7% vs 8.6%; Yates P = .035; OR = 4.51). Such association of protective AA genotype with ARE, as observed also in autoimmunity, was associated with an increased level of sCTLA-4 induced by the polymorphism, which blocks B7-flCTLA-4 interactions, enhancing T-cell reactivity by preventing transduction of inhibitory signals. Considering the various polymorphic sites in the haplotype, we observed a significant increase in ARE among patients of the CTLA4 +49A/CT60A (HF = 51.5% vs 29.5%; P = .014; OR = 2.545) and a reduction among the +49A/CT60G (17.6% vs 33.8%; P = .04; OR = 0.4193) 2-loci haplotype, As regards the -1147/-318/+49/CT60 CTLA-4 4-loci haplotypes, we observed a significantly higher frequency of the CCAA haplotype in ARE patients comparison with those free of rejection (HF = 51.8% vs 31.1%, P = .046 OR = 2.363). These findings are consistent with those observed in allogeneic stem cell transplantation, wherein patients with CT60 AA showed a major incidence of graft-versus-host disease. An association of protective AA genotype with ARE, as observed also in autoimmunity was associated with an increased level of sCTLA-4 induced by this polymorphism, which blocking the B7-flCTLA-4 interaction, would enhance T-cell reactivity by preventing transduction of inhibitory signals.

For anti-HLA-specific donor antibodies detection by flow cytometry cytotoxic crossmatches comparison of methods

Anti-HLA-specific donor antibodies induce rapid, irreversible destruction of the transplant (hyperacute rejection) that today happens rarely due to immunologic studies-prospective crossmatch-of patients awaiting the kidney graft. The usual approach for pretransplant donor/recipient evaluation is based on 2 methods: (1) the cytotoxic complement crossmatch (CDC) and (2) the flow cytometric crossmatch (FCX). The CDC crossmatch is positive when complement-fixing antibodies are present, an absolute contraindication to kidney transplantation. The more sensitive FCX-positive crossmatch detects low concentrations of unable to fix performed antibodies complement. It is an "index" of possible damage due to accelerated rejection. The target of our study was to develop a cytotoxic flow cytometry crossmatch (cFCX) that detected cytotoxic antibodies move sensitively than the traditional CDC method and also was less subjective and more standardized for interpretation studying sera from 23 patients; the cFCX showed the requested efficiency characteristics even in an emergency. In addition, the new method permited one to calculate a cutoff for positivity (average value of the negative control + 2 standard deviations), assuring an "objective" interpretation of the results that agreed with the CDC but was more sensitive and accurate allowing solution of ambiguous results for cases of "doubt"-positive CDC crossmatch. Furthermore, our aim was to correlate the effect of the strength of the anti-HLA antibodies determined by mean fluorescence intensity value of LabScreen Single Antigen beads with results of CDC, cFCX, and FCX methods.

Identification of the novel HLA-B*50:18 allele variant in an Italian unrelated bone marrow donor

The HLA-B*50:18 allele differs from the closest related B*50:01:01 by one nucleotide substitution at position 454 in exon 3.

Interferon-α Therapy and Anti–Human Leukocyte Antigen Antibodies in Hepatitis C Virus–Positive Patient: Case Report

Interferon-alpha (IFN-alpha) is currently the only treatment for patients with chronic hepatitis C. Yet it can induce acute renal transplantation rejection possibly by stimulating humoral responses. We tested patient sera for detection of donor-specific anti-human leukocyte antigen (HLA) antibodies observing an increased panel-reactive antibodies value after IFN-alpha therapy. Then, we also investigated whether antiviral treatment with IFN-alpha was related to an increased and/or different production of class I and class II anti-HLA antibodies. Patient sera analysis performed by a cytofluorimetric method using flow PRA tests showed the appearance of new HLA-antibody specificities. This study underlined that INF-alpha therapy modifies a patient's immune profile; hence, it is recommended to confirm HLA-antibody specificities after treatment in order to protect recipients from enhanced rejection risk owing to a false-negative donor-specific cross-match.

Waiting list for kidney transplants

Medical and technological progress have made kidney transplants an effective, alternative therapy to dialysis for patients suffering from chronic kidney failure. Transplantation improves the quality of life of these patients significantly; however, waiting lists are long and this is because of the attitude of the general public to organ donation, not a lack of medical expertise. In fact, the only limiting factor in kidney transplant is the opposition to donation expressed by the deceased or family members. Herein we outline the distribution of patients on the kidney transplant waiting list in the Regional Transplant Centre for Abruzzo and Molise in L'Aquila, Italy, and highlight the reasons why patients are withdrawn from the list, the main reason being a deterioration in patient condition after long periods of dialysis.

Anti-HLA antibodies in kidney transplanted patients

Anti-human leukocyte antibodies (HLA) play a central role in graft survival, particularly in kidney transplantation. The presence of preformed donor specific anti-HLA antibodies is always excluded before transplantation by performing crossmatches using current and historic recipient serum samples. Several recent studies have observed a correlation between HLA antibodies and graft rejection. It has been suggested that these antibodies should be monitored routinely after kidney transplant to predict graft failure. Here in report the results of a study of on serum samples from 111 kidney transplant recipients that were monitored for anti-HLA antibodies using flow cytometry. Anti-HLA antibodies were only detected in four pre-immunized patients and showed the same HLA specificity that was present before the transplantation (in two cases against previous graft antigens). Furthermore, only two patients with functioning grafts developed anti-HLA antibodies, at 1 month and 1 year after the transplantation. However, they were not donor specific, but probably related to posttransplant transfusions. In our study, none of the patients who suffered an adverse event during the first year (including two with histologically documented acute rejection) developed anti-HLA antibodies. These results are probably related to the use of mycophenolate mofetil, which may reduce the incidence of HLA antibodies. We cannot exclude the possibility that antibodies produced by some patients may not be detectable because they are attached to the graft.

Identification of the novel allele B*4427 and a confirmatory sequence (B*44022)

This report presents a novel allele, HLA-B*4427, which was identified in a bone marrow donor of Caucasian origin, and a confirmatory sequence (B*44022). Sequence analysis revealed the new allele differs from B*44021 by a single nucleotide exchange at position 668 (C-->T), which is located in exon 4. At the protein level, it is the only B*44 variant to produce an Ala in place of a Val at codon 199. Its structure suggests that it may have originated from a point mutation in B*44021 or by gene conversion with a variety of HLA-B alleles. Cloning and sequencing of the allele B*44022 revealed a sequence identical to B*44021 and B*44 exon 4, with the codon GTC (Val) in position 199.

Immunosuppressive molecules produced by Sertoli cells cultured in vitro: biological effects on lymphocytes

In the present study we have analyzed the proteins secreted in vitro by murine Sertoli cells to identify immunosuppressive factors. Our data show that Sertoli cells secrete molecules capable to inhibit proliferation of lymphocytes activated in vitro. Cytophluorimetric analysis indicates that treated cells are arrested in the G1 phase of cell cycle. The inhibitory activity is specific for both B or T lymphocytes but not for other non-lymphoid cells and is associated to proteins, heat and freeze stable, with Mr of more than 30 kDa. Lymphocytes treated with Sertoli immunosuppressive proteins drastically reduce the secretion of interleukin-2.