Comparative single-cell transcriptomic profile of hybrid immunity induced by adenovirus vector-based COVID-19 vaccines.

In this study, antibody response and a single-cell RNA-seq analysis were conducted on peripheral blood mononuclear cells from five different groups: naïve subjects vaccinated with AZD1222 (AZ) or Ad5-nCoV (Cso), individuals previously infected and later vaccinated (hybrid) with AZD1222 (AZ-hb) or Ad5-nCoV (Cso-hb), and those who were infected and had recovered from COVID-19 (Inf). The results showed that AZ induced more robust neutralizing antibody responses than Cso. The single-cell RNA data revealed a high frequency of memory B cells in the Cso and Cso-hb. In contrast, AZ and AZ-hb groups exhibited the highest proportion of activated naïve B cells expressing CXCR4. Transcriptomic analysis of CD4+ and CD8+ T cells demonstrated a heterogeneous response following vaccination, hybrid immunity, or natural infection. However, a single dose of Ad5-nCoV was sufficient to strongly activate CD4+ T cells (naïve and memory) expressing ANX1 and FOS, similar to the hybrid response observed with AZ. An interesting finding was the robust activation of a subset of CD8+ T cells expressing GZMB, GZMH, and IFNG genes in the Cso-hb group. Our findings suggest that both vaccines effectively stimulated the cellular immune response; however, the Ad5-nCoV induced a more robust CD8+ T-cell response in previously infected individuals.

Gene expression during the development of Mycobacterium smegmatis biofilms on hydroxyapatite surfaces / Expresión génica durante el desarrollo de biopelículas de Mycobacterium smegmatis en superficies de hidroxiapatita

Bacterial biofilms are a consortium of bacteria that are strongly bound to each other and the surface on which they developed irreversibly. Bacteria can survive adverse environmental conditions and undergo changes when transitioning from a planktonic form to community cells. The process of mycobacteria adhesion is complex, involving characteristics and properties of bacteria, surfaces, and environmental factors; therefore, the formation of different biofilms is possible. Cell wall-, lipid-, and lipid transporter-related genes (glycopeptidolipids, GroEL1, protein kinase) are important in mycobacterial biofilm development. We investigated gene expression during in vitro development of Mycobacterium smegmatis biofilms on a hydroxyapatite (HAP) surface. Biofilm formation by M. smegmatis cells was induced for 1, 2, 3, and 5 days on the HAP surface. Mycobacteria on polystyrene generated an air–liquid interface biofilm, and on the fifth day, it increased by 35% in the presence of HAP. Six genes with key roles in biofilm formation were analyzed by real-time RT‒qPCR during the biofilm formation of M. smegmatis on both abiotic surfaces. The expression of groEL1, lsr2, mmpL11, mps, pknF, and rpoZ genes during biofilm formation on the HAP surface did not exhibit significant changes compared to the polystyrene surface. These genes involved in biofilm formation are not affected by HAP.(AU)

Gene expression during the development of Mycobacterium smegmatis biofilms on hydroxyapatite surfaces.

Bacterial biofilms are a consortium of bacteria that are strongly bound to each other and the surface on which they developed irreversibly. Bacteria can survive adverse environmental conditions and undergo changes when transitioning from a planktonic form to community cells. The process of mycobacteria adhesion is complex, involving characteristics and properties of bacteria, surfaces, and environmental factors; therefore, the formation of different biofilms is possible. Cell wall-, lipid-, and lipid transporter-related genes (glycopeptidolipids, GroEL1, protein kinase) are important in mycobacterial biofilm development. We investigated gene expression during in vitro development of Mycobacterium smegmatis biofilms on a hydroxyapatite (HAP) surface. Biofilm formation by M. smegmatis cells was induced for 1, 2, 3, and 5 days on the HAP surface. Mycobacteria on polystyrene generated an air-liquid interface biofilm, and on the fifth day, it increased by 35% in the presence of HAP. Six genes with key roles in biofilm formation were analyzed by real-time RT‒qPCR during the biofilm formation of M. smegmatis on both abiotic surfaces. The expression of groEL1, lsr2, mmpL11, mps, pknF, and rpoZ genes during biofilm formation on the HAP surface did not exhibit significant changes compared to the polystyrene surface. These genes involved in biofilm formation are not affected by HAP.

Antimycobacterial Precatorin A Flavonoid Displays Antibiofilm Activity against Mycobacterium bovis BCG.

The aim of this study was to evaluate the potential antibiofilm activity of Rhynchosia precatoria (R. precatoria) compounds over Mycobacterium bovis BCG (M. bovis BCG) as a model for Mycobacterium tuberculosis (Mtb). We evaluated the antibiofilm activity as the ability to both inhibit biofilm formation and disrupt preformed biofilms (bactericidal) of R. precatoria compounds, which have been previously described as being antimycobacterials against Mtb. M. bovis BCG developed air-liquid interface biofilms with surface attachment ability and drug tolerance. Of the R. precatoria extracts and compounds that were tested, precatorin A (PreA) displayed the best biofilm inhibitory activity, as evaluated by biofilm biomass quantification, viable cell count, and confocal and atomic force microscopy procedures. Furthermore, its combination with isoniazid at subinhibitory concentrations inhibited M. bovis BCG biofilm formation. Nonetheless, neither PreA nor the extract showed bactericidal effects. PreA is the R. precatoria compound responsible for biofilm inhibitory activity against M. bovis BCG.

19n01, a broadly neutralizing antibody against omicron BA.1, BA.2, BA.4/5, and other SARS-CoV-2 variants of concern.

This study reports the isolation and characterization of a human monoclonal antibody (mAb) called 19n01. This mAb was isolated by using single-cell RNAseq of B cells from donors infected with the ancestral strain. This mAb possesses a potent and broad capacity to bind and neutralize all previously circulating variants of concern (VOCs), including Omicron sublineages BA.1, BA.2, and BA.4/5. The pseudovirus neutralization assay revealed robust neutralization capacity against the G614 strain, BA.1, BA.2, and BA.4/5, with inhibitory concentration (IC50) values ranging from 0.0035 to 0.0164 µg/mL. The microneutralization assay using the G614 strain and VOCs demonstrated IC50 values of 0.013-0.267 µg/mL. Biophysical and structural analysis showed that 19n01 cross-competes with ACE2 binding to the receptor-binding domain (RBD) and the kinetic parameters confirmed the high affinity against the Omicron sublineages (KD of 61 and 30 nM for BA.2 and BA.4/5, respectively). These results suggest that the 19n01 is a remarkably potent and broadly reactive mAb.

Socioeconomic, Clinical, and Molecular Features of Breast Cancer Influence Overall Survival of Latin American Women.

Molecular profile of breast cancer in Latin-American women was studied in five countries: Argentina, Brazil, Chile, Mexico, and Uruguay. Data about socioeconomic characteristics, risk factors, prognostic factors, and molecular subtypes were described, and the 60-month overall cumulative survival probabilities (OS) were estimated. From 2011 to 2013, 1,300 eligible Latin-American women 18 years or older, with a diagnosis of breast cancer in clinical stage II or III, and performance status ≦̸1 were invited to participate in a prospective cohort study. Face-to-face interviews were conducted, and clinical and outcome data, including death, were extracted from medical records. Unadjusted associations were evaluated by Chi-squared and Fisher's exact tests and the OS by Kaplan-Meier method. Log-rank test was used to determine differences between cumulative probability curves. Multivariable adjustment was carried out by entering potential confounders in the Cox regression model. The OS at 60 months was 83.9%. Multivariable-adjusted death hazard differences were found for women living in Argentina (2.27), Chile (1.95), and Uruguay (2.42) compared with Mexican women, for older (≥60 years) (1.84) compared with younger (≤40 years) women, for basal-like subtype (5.8), luminal B (2.43), and HER2-enriched (2.52) compared with luminal A subtype, and for tumor clinical stages IIB (1.91), IIIA (3.54), and IIIB (3.94) compared with stage IIA women. OS was associated with country of residence, PAM50 intrinsic subtype, age, and tumor stage at diagnosis. While the latter is known to be influenced by access to care, including cancer screening, timely diagnosis and treatment, including access to more effective treatment protocols, it may also influence epigenetic changes that, potentially, impact molecular subtypes. Data derived from heretofore understudied populations with unique geographic ancestry and sociocultural experiences are critical to furthering our understanding of this complexity.

Analysis of IgG, IgA and IgM antibodies against SARS-CoV-2 spike protein S1 in convalescent and vaccinated patients with the Pfizer-BioNTech and CanSinoBio vaccines.

The SARS-CoV-2 virus was detected for the first time in December 2019 in Wuhan, China. Currently, this virus has spread around the world, and new variants have emerged. This new pandemic virus provoked the rapid development of diagnostic tools, therapies and vaccines to control this new disease called COVID-19. Antibody detection by ELISA has been broadly used to recognize the number of persons infected with this virus or to evaluate the response of vaccinated individuals. As the pandemic spread, new questions arose, such as the prevalence of antibodies after natural infection and the response induced by the different vaccines. In Mexico, as in other countries, mRNA and viral-vectored vaccines have been widely used among the population. In this work, we developed an indirect ELISA test to evaluate S1 antibodies in convalescent and vaccinated individuals. By using this test, we showed that IgG antibodies against the S1 protein of SARS-CoV-2 were detected up to 42 weeks after the onset of the symptoms, in contrast to IgA and IgM, which decreased 14 weeks after the onset of symptoms. The evaluation of the antibody response in individuals vaccinated with Pfizer-BioNTech and CanSinoBio vaccines showed no differences 2 weeks after vaccination. However, after completing the two doses of Pfizer-BioNTech and the one dose of CanSinoBio, a significantly higher response of IgG antibodies was observed in persons vaccinated with Pfizer-BioNTech than in those vaccinated with CanSinoBio. In conclusion, these results confirm that after natural infection with SARS-CoV-2, it is possible to detect antibodies for up to 10 months. Additionally, our results showed that one dose of the CanSinoBio vaccine induces a lower response of IgG antibodies than that induced by the complete scheme of the Pfizer-BioNTech vaccine.

The Dichloromethane Fraction of Croton sonorae, A Plant Used in Sonoran Traditional Medicine, Affect Entamoeba histolytica Erythrophagocytosis and Gene Expression.

Intestinal parasites are a global problem, mainly in developing countries. Obtaining information about plants and compounds that can combat gastrointestinal disorders and gastrointestinal symptoms is a fundamental first step in designing new treatment strategies. In this study, we analyzed the antiamoebic activity of the aerial part of Croton sonorae. The dichloromethane fraction of C. sonorae (CsDCMfx) contained flavonoids, terpenes, alkaloids, and glycosides. The ultrastructural morphology of the amoebae treated for 72 h with CsDCMfx was completely abnormal. CsDCMfx reduced erythrophagocytosis of trophozoites and the expression of genes involved in erythrocyte adhesion (gal/galnac lectin) and actin cytoskeleton rearrangement in the phagocytosis pathway (rho1 gtpase and formin1). Interestingly, CsDCMfx decreased the expression of genes involved in Entamoeba histolytica trophozoite pathogenesis, such as cysteine proteases (cp1, cp4, and cp5), sod, pfor, and enolase. These results showed that C. sonorae is a potential source of antiamoebic compounds.

Serum IgG Responses to gp15 and gp40 Protein-Derived Synthetic Peptides From Cryptosporidium parvum.

Cryptosporidium spp. are responsible for moderate to severe diarrhea, mainly in children and immunocompromised patients. Using ELISA, the recognition of synthetic peptides generated from the sequences of the Cryptosporidium parvum gp40 and gp15 proteins by serum IgM and IgG antibodies from patients infected (cases) with Cryptosporidium hominis, C. parvum, and Cryptosporidium canis, and uninfected individuals (controls) was evaluated. A statistically significant difference (p = 0.0025) was found in terms of the recognition of peptides A133 and A32 between cases and controls. Additional studies are necessary to understand the potential of these peptides as vaccine candidates.

Tonsil conventional dendritic cells are not infected by porcine reproductive and respiratory syndrome virus.

Porcine reproductive and respiratory syndrome virus (PRRSV) infects monocyte-derived DCs, and previous reports have shown that PRRSV does not infect conventional DCs (cDCs) in vitro, but the effects on cDCs from lymphoid tissues are unknown. This study analyzed the response and susceptibility of tonsil DEC205+cDCs from infected pigs. We confirmed the phenotype and lineage of bona fide tonsil cDCs with the mRNA expression of FLT3+ and the phenotype MHCII+CADM1highDEC205+ (DEC205+cDCs). These cells were not infected by PRRSV, whereas CD163+ tonsil cells were infected. The numbers of tonsil cDCs and CD163+ cells were not affected by PRRSV, in contrast to the reduction in alveolar macrophage numbers. DEC205+cDCs exhibited an increase in the expression of IL-12 at 5 days postinfection, suggesting a proinflammatory response by these cells to the virus. In summary, this study confirms that, in vitro and in vivo, cDCs are not susceptible to PRRSV but can respond against it.

Response of the cDC1 and cDC2 subtypes of tracheal dendritic cells to porcine reproductive and respiratory syndrome virus.

Porcine reproductive and respiratory syndrome virus (PRRSV) is the most important disease affecting the swine industry worldwide. Although monocytes and macrophages, especially tissue-resident and alveolar macrophages, are the primary target of PRRSV, monocyte- and bone marrow-derived dendritic cells (DCs) are also susceptible to PRRSV infection. It has been shown that lung DCs cannot be infected with PRRSV, but the response and susceptibility of bona fide conventional DC subtypes (cDCs; cDC1 and cDC2) is unknown. In this work, evaluation of the response of tracheal cDC1 and cDC2 subsets to PRRSV revealed differential cytokine expression, whereby cDC1 subsets expressed higher levels of IFN-α and cDC2 subsets more IL-10. Toll-like receptors (TLRs) were also affected: cDC2 cells induced greater upregulation of TLR2 and TLR4, and CD163+ cells showed TLR3 upregulation. However, we could not demonstrate under our experimental conditions that cDC1 and cCD2 subsets are susceptible to PRRSV infection. Our findings show the effects of PRRSV on cDC1 and cDC2 subsets and that these cells were not infected by PRRSV.

Characterization and expression of DEC205 in the cDC1 and cDC2 subsets of porcine dendritic cells from spleen, tonsil, and submaxillary and mesenteric lymph nodes.

Conventional dendritic cells (cDCs) are divided into the following different subtypes: cDC1, which promotes a Th1 response, and cDC2, which stimulates a Th2 and Th17 response. These cells have not been characterized in porcine lymphoid tissues. DEC205 is a receptor that increases antigen presentation and allows DCs to cross-present antigens. The objectives of this work were to characterize cDCs subsets in the tonsil, submaxillary and mesenteric lymph nodes and spleen lymphoid tissues and to determine their expression of DEC205 by flow cytometry. The cDC1 (MHCIIhighCADM1highCD172a-/low) and cDC2 (MHCIIhighCADM1highCD172a+) phenotypes were confirmed by the expression of characteristic cDC1 and cDC2 transcripts (FLT3, XCR1 and FCER1α). Among all lymphoid tissues, the spleen had the highest frequency of total cDCs. The cDC1:cDC2 ratio showed that all lymph tissues had higher levels of cDC1 than levels of cDC2. DEC205+ cDCs were found in all analyzed tissues, albeit with different frequencies. Our research will facilitate the study on the function of these cells and the investigation of the strategies for DEC205 targeting and functional studies.

Clinical Manifestations of Cryptosporidiosis and Identification of a New Cryptosporidium Subtype in Patients From Sonora, Mexico.

The aim of this study was to identify the clinical manifestations of cryptosporidiosis and the distribution of Cryptosporidium spp. and subtypes in children in Sonora, Mexico. Two subtypes of C. parvum, including IIaA15G2R1 and IIcA5G3a, and 6 subtypes of Cryptosporidium hominis, including IaA14R3, IaA15R3, IbA12G3, IdA23, IeA11G3T3, and a new subtype IaA14R11, were identified. Cryptosporidium as an etiologic agent for acute gastroenteritis is discussed.

A rapid alternative method to evaluate T-cell hybridoma activation using an improved cytokine (IL-2) secretion assay.

T-cell hybridoma assays have been widely used for the in vitro study of antigen processing and presentation because they represent an unlimited source of cells and they bypass the difficulty of maintaining T-cell clones in culture. One of the most widely used methods to assess hybridoma activation is measurement of CTLL-2 cell proliferation, which is dependent on IL-2. However, continuous culture of this cell line results in a loss of sensitivity, and significant interassay variability can occur. Therefore, our goal was to develop a method to assess T-cell hybridoma activation that was fast and sensitive with low variability based on the IL-2 secretion assay. The assay used flow cytometry detection and employed the hen egg lysozyme (HEL)-specific 3A9 hybridoma as a model. The original murine IL-2 secretion assay protocol from Miltenyi Biotec® was tested and modified; the conjugated capture antibody (anti-CD45-anti-IL-2) was added together with the stimulus at the beginning of the antigen presentation assay instead of after antigenic stimulation. With this modification, the percentage of detectable CD4+IL-2+ cells following HEL stimulation rose from 4.5% with the original protocol (0.8% without stimulus) to 94.1% (0.8% without stimulus) with the newly proposed method under the conditions evaluated in this study. This modification allowed us to evaluate the activation of hybridomas directly and more rapidly (~18h) than the reference method that assayed CTLL-2 cell proliferation using the MTT reduction assay (~48h). In conclusion, the proposed method offered a rapid alternative for screening T-cell hybridomas and evaluating their antigen-specific activation.

Comparison of the genetic variability of Blastocystis subtypes between human carriers from two contrasting climatic regions of México.

Blastocystis sp. is an anaerobic intestinal microorganism commonly identified in the feces of several animals, including humans. Blastocystis exhibits high genetic polymorphism and at least 17 subtypes (ST) have been identified; ST1-ST3 are frequently found in the Americas. Furthermore, in vitro assays have shown that temperature and humidity can affect the viability of Blastocystis cysts. In this study, we describe the genetic variability and genetic differentiation among and within Blastocystis STs in adults and children from the cities of Hermosillo and Morelia cities, which represent arid and humid subtropical climatic regions of México, respectively. Phylogenetic and genetic diversity was assessed by analyzing a region of the small subunit ribosomal DNA (SSU rDNA) gene as a marker. Blastocystis ST3 and ST1 were associated with children from Hermosillo and Morelia, respectively. An analysis of the nucleotide diversity (π) and haplotype polymorphism (θ) indexes showed that they were similar within each ST, but different between ST1 and ST3. Interestingly, the group of symptomatic carriers from Hermosillo showed scarce mean nucleotide diversity compared to the asymptomatic carriers (0.0039±0.0030 and 0.0329±0.0286, respectively). Furthermore, the gene flow and genetic differentiation indexes between the children and adults suggested that the Blastocystis haplotypes in the adult carriers were "highly mobile" among humans, while the haplotypes found in the children were more isolated and genetically differentiated between them.

Cryptosporidium canis in Two Mexican Toddlers.

Cryptosporidium canis is reported for the first time in 2 toddlers in Northwestern Mexico. The 2 toddlers (33 and 34 months old) were symptomatic at diagnosis, presenting diarrhea and fever, and 1 case presented chronic malnutrition. Both toddlers were HIV-negative. C. canis was identified by SspI and VspI restriction enzyme digestion of the 18S rRNA polymerase chain reaction products and confirmed by sequence analysis.

Prevalent HLA Class II Alleles in Mexico City Appear to Confer Resistance to the Development of Amebic Liver Abscess.

Amebiasis is an endemic disease and a public health problem throughout Mexico, although the incidence rates of amebic liver abscess (ALA) vary among the geographic regions of the country. Notably, incidence rates are high in the northwestern states (especially Sonora with a rate of 12.57/100,000 inhabitants) compared with the central region (Mexico City with a rate of 0.69/100,000 inhabitants). These data may be related to host genetic factors that are partially responsible for resistance or susceptibility. Therefore, we studied the association of the HLA-DRB1 and HLA-DQB1 alleles with resistance or susceptibility to ALA in two Mexican populations, one each from Mexico City and Sonora. Ninety ALA patients were clinically diagnosed by serology and sonography. Genomic DNA was extracted from peripheral blood mononuclear cells. To establish the genetic identity of both populations, 15 short tandem repeats (STRs) were analyzed with multiplexed PCR, and the allelic frequencies of HLA were studied by PCR-SSO using LUMINEX technology. The allele frequencies obtained were compared to an ethnically matched healthy control group (146 individuals). We observed that both affected populations differed genetically from the control group. We also found interesting trends in the population from Mexico City. HLA-DQB1*02 allele frequencies were higher in ALA patients compared to the control group (0.127 vs 0.047; p= 0.01; pc= NS; OR= 2.9, 95% CI= 1.09-8.3). The less frequent alleles in ALA patients were HLA-DRB1*08 (0.118 vs 0.238 in controls; p= 0.01; pc= NS; OR= 0.42, 95% CI= 0.19-0.87) and HLA-DQB1*04 (0.109 vs 0.214; p= 0.02; pc= NS; OR= 0.40, 95% CI= 0.20-0.94). The haplotype HLA-DRB1*08/-DQB1*04 also demonstrated a protective trend against the development of this disease (0.081 vs. 0.178; p=0.02; pc=NS; OR= 0.40, 95% CI= 0.16-0.93). These trends suggest that the prevalent alleles in the population of Mexico City may be associated with protection against the development of ALA.