Phenotypic analysis of peripheral B cell populations during Mycobacterium tuberculosis infection and disease

Abstract Background Mycobacterium tuberculosis (Mtb) remains an unresolved threat resulting in great annual loss of life. The role of B cells during the protective immunity to Mtb is still unclear. B cells have been described as effector cells in addition to their role as antibody producing cells during disease. Here we aim to identify and characterize the frequency of peripheral B-cell subpopulations during active Tuberculosis and over treatment response. Analysis were done for both class switched (CS) and non-class switched (NCS) phenotypes. Methods We recruited participants with active untreated pulmonary Tuberculosis, other lung diseases and healthy community controls. All groups were followed up for one week from recruitment and the TB cases till the end of treatment (month 6). Results Peripheral blood samples were collected, stained with monoclonal antibodies to CD19 + cells, Immunoglobulin (Ig) M, plasma cells (CD 138 + ), marker of memory (CD27 + ), immune activation (CD23 + ) and acquired on a flow cytometer. Circulating Marginal zone B cells (CD19 + IgM + CD23 − CD27 + ) and memory phenotypes are able to distinguish between TB diagnosis and end of treatment. The frequency of mature B cells from TB cases are lower than that of other-lung diseases at diagnosis. A subpopulation of activated memory B cells (CD19 + IgM + CD23 + CD27 + ) cells are present at the end of TB treatment. Conclusions This study identified distinctive B cell subpopulations present during active TB disease and other lung disease conditions. These cell populations warrants further examination in larger studies as it may be informative as cell markers or as effectors/regulators in TB disease or TB treatment response

Polymerase chain reaction amplifying mycobacterial DNA from aspirates obtained by endoscopic ultrasound allows accurate diagnosis of mycobacterial disease in HIV-positive patients with abdominal lymphadenopathy

Abdominal lymphadopathy in Human Immunodeficiency Virus (HIV) infection remains a diagnostic challenge. We performed a prospective cohort study recruiting thirty-one symptomatic HIV+ patients with abdominal lymphadenopathy assessing diagnostic yield of endoscopic ultrasound (EUS) fine needle aspiration (FNA). Mean age was 38 years, 52% were female, mean CD4 count and viral load were 124 cells/pl, and 4 log respectively. EUS confirmed additional mediastinal nodes in 26 %. Porta- hepatis was the most common abdominal site. EUS FNA was subjected to cytology, culture and polymerase chain reaction (PCR) analysis. Mycobacterial infections were confirmed in 67.7% and 31% had reactive lymphadenopathy. Cytology and culture had low sensitivity whereas PCR identified 90% of mycobacterial infections. Combining appearance of EUS FNA and cytology a diagnostic algorithm was developed to indicate when analysis with PCR would be useful. PCR performed on an EUS guided aspirate was highly accurate in confirming mycobacterial disease and determining genotypic drug resistance.South African Gastroenterological Society (SAGES)/ Astra Zeneca Fellowship in Gastroenterology awarded to Schalk van der Merwehttp://www.journals.elsevier.com/ultrasound-in-medicine-and-biology/hb201

CD14+ macrophages that accumulate in the colon of African AIDS patients express pro-inflammatory cytokines and are responsive to lipopolysaccharide

BACKGROUND : Intestinal macrophages are key regulators of inflammatory responses to the gut microbiome and play a central role in maintaining tissue homeostasis and epithelial integrity. However, little is known about the role of these cells in HIV infection, a disease fuelled by intestinal inflammation, a loss of epithelial barrier function and increased microbial translocation (MT). METHODS : Phenotypic and functional characterization of intestinal macrophages was performed for 23 African AIDS patients with chronic diarrhea and/or weight loss and 11 HIV-negative Africans with and without inflammatory bowel disease (IBD). AIDS patients were treated with cotrimoxazole for the prevention of opportunistic infections (OIs). Macrophage phenotype was assessed by flow cytometry and immuno-histochemistry (IHC); production of proinflammatory mediators by IHC and Qiagen PCR Arrays; in vitro secretion of cytokines by the Bio-Plex Suspension Array System. Statistical analyses were performed using Spearman’s correlation and Wilcoxon matched-pair tests. Results between groups were analyzed using the Kruskal-Wallis with Dunn’s post-test and the Mann–Whitney U tests. RESULTS : None of the study participants had evidence of enteric co-infections as assessed by stool analysis and histology. Compared to healthy HIV-negative controls, the colon of AIDS patients was highly inflamed with increased infiltration of inflammatory cells and increased mRNA expression of proinflammatory cytokine (tumour necrosis factor (TNF)-α, interleukin (IL)-1β, IFN-γ, and IL-18), chemokines (chemokine (C-C motif) ligand (CCL)2 and chemokine (C-X-C) motif ligand (CXCL)10) and transcription factors (TNF receptor-associated factor (TRAF)6 and T-box (TXB)21). IHC revealed significant co-localization of TNF-α and IL-1β with CD68+ cells. As in IBD, HIV was associated with a marked increase in macrophages expressing innate response receptors including CD14, the co-receptor for lipopolysaccharide (LPS). The frequency of CD14+ macrophages correlated positively with plasma LPS, a marker of MT. Total unfractionated mucosal mononuclear cells (MMC) isolated from the colon of AIDS patients, but not MMC depleted of CD14+ cells, secreted increased levels of proinflammatory cytokines ex vivo in response to LPS CONCLUSIONS : Intestinal macrophages, in the absence of overt OIs, play an important role in driving persistentinflammation in HIV patients with late-stage disease and diarrhea. These results suggest intensified treatmentstrategies that target inflammatory processes in intestinal macrophages may be highly beneficial in restoringthe epithelial barrier and limiting MT in HIV-infected patients.This research and selected researchers (EC, TR, PM, SM and CS) were funded in part by a grant from the Delegation of the European Union to South Africa: “Drug Resistance Surveillance and Treatment Monitoring Network for the Public Sector HIV Antiretroviral Treatment Programme in the Free State – Sante 2007/147-790” and by a grant from the National Research Council of South Africa, Unlocking the Future 61509.http://www.biomedcentral.com/bmcinfectdisam201

Standards in semen examination:publishing reproducible and reliable data based on high-quality methodology

Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility of scientific publications. This is even more important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, and the International Standard ISO 23162:2021. With these tools, we propose that authors should be instructed to follow these laboratory methods in order to publish studies in peer-reviewed journals, preferable by using a checklist as suggested in an Appendix to this article.Peer reviewe

A visceral pseudoaneurysm : management by EUS-guided thrombin injection

No abstract available

The functional response of B cells to antigenic stimulation: a preliminary report of latent tuberculosis

Mycobacterium tuberculosis (M.tb) remains a successful pathogen, causing tuberculosis disease numbers to constantly increase. Although great progress has been made in delineating the disease, the host-pathogen interaction is incompletely described. B cells have shown to function as both effectors and regulators of immunity via non-humoral methods in both innate and adaptive immune settings. Here we assessed specific B cell functional interaction following stimulation with a broad range of antigens within the LTBI milieu. Our results indicate that B cells readily produce pro- and anti-inflammatory cytokines (including IL-1β, IL-10, IL-17, IL-21 and TNF-α) in response to stimulation. TLR4 and TLR9 based stimulations achieved the greatest secreted cytokine-production response and BCG stimulation displayed a clear preference for inducing IL-1β production. We also show that the cytokines produced by B cells are implicated strongly in cell-mediated communication and that plasma (memory) B cells (CD19CD27CD138) is the subset with the greatest contribution to cytokine production. Collectively our data provides insight into B cell responses, where they are implicated in and quantifies responses from specific B cell phenotypes. These findings warrant further functional B cell research with a focus on specific B cell phenotypes under conditions of active TB disease to further our knowledge about the contribution of various cell subsets which could have implications for future vaccine development or refined B cell orientated treatment in the health setting

Ostrich ejaculate characteristics and male libido around equinox and solstice dates

CITATION: Muvhali, P. T., et al. 2020. Ostrich ejaculate characteristics and male libido around equinox and solstice dates. Tropical Animal Health and Production, 52:2609–2619, doi:10.1007/s11250-020-02299-2.The original publication is available at https://link.springer.comThe study evaluated the effect of time of the year in which changes in photoperiod occurs on ostrich semen characteristics and male libido. Semen was collected for 5 days before, on and 5 days after winter solstice (21 June 2016), spring equinox (22 September 2016), summer solstice (21 December 2016) and autumn equinox (20 March 2017) in the southern hemisphere. Semen was collected from 10 South African Black ostrich males (average age ± standard deviation; 4.5 ± 2.27 years) using the dummy female. Semen volume, sperm concentration, total sperm per ejaculate, sperm motility traits, percentage of normal sperm, head and tail abnormalities and percentage of affected sperm in the hypo-osmotic swelling test (HOS) were evaluated. Male libido defined as the willingness of males to mount the dummy female was also recorded. Semen samples collected around summer solstice, spring and autumn equinox were higher in sperm concentration and sperm output compared with winter solstice (P < 0.05). Study periods did not influence semen volume, sperm motility traits, the percentage of normal sperm, head abnormalities and HOS. Tail abnormalities were higher around winter solstice than around spring equinox (P < 0.05). Male libido and the success of semen collection were significantly higher around spring equinox (P < 0.05). Changes in photoperiod in the southern hemisphere do not affect semen production in ostriches. However, high sperm output and male libido around spring equinox and summer solstice dates suggest that these periods may be preferred for semen collection for artificial insemination and storage purposes.https://link.springer.com/article/10.1007%2Fs11250-020-02299-2Preprin

Plasma (memory) B cells may be key B cells subsets during innate recruitment of B cells during tuberculous challenge.

<p>B cells were stimulated for 16-hours with BCG and PPD respectively. Flow cytometric analysis of various B cell subsets indicated that plasma (memory) B cells were the major contributors for the dual production of IL-17 and IL-21, implicating them in the potential recruitment of innate-like B cells during <i>M</i>.<i>tb</i> challenge. Each box-plot represents a fraction from each B cell subset to the total cytokine production.</p

B cell flow cytometry gating strategy.

<p>a) Initial cell- inclusion and exclusion gating. b) The main B cell phenotypes from which cytokine production were assessed includes memory B cells (CD19⁺CD27⁺), mature B cells (CD19⁺CD27^-CD138^-), plasma B cells (CD19⁺CD138⁺) and plasma (memory) B cells (CD19⁺CD27⁺CD138⁺). c) Further downstream cytokine analysis were done following the identification of the main B cell subsets in b), by plotting respective cytokines against one another. Appropriate cut-off levels for the gating strategy were used as determined by using FMO control samples.</p