The percentage of Monocytes CD39+ is higher in Pregnant COVID-19 than in Non-Pregnant COVID-19 patients

Current medical guidelines consider COVID-19 pregnant women a high-risk group. Physiological gestation down-regulates the immunological response to maintain "maternal-fetal tolerance"; hence, a SARS-CoV-2 infection constitutes a potentially threatening condition to both the mother and the fetus. To establish the immune profile in pregnant COVID-19+ patients a cross-sectional study was conducted. Leukocyte immunophenotype, mononuclear leukocyte response to polyclonal stimulus, and cytokine/chemokine serum concentration were analyzed in pregnant fifteen COVID-19+ and control groups (fifteen non-pregnant COVID-19+, and thirteen pregnant COVID-19- women). Pregnant COVID-19+ patients exhibit lower percentages of monocytes HLA-DR+ compared with control groups. Nevertheless, pregnant COVID-19+ women show a higher percentage of monocytes CD39+ than controls. Furthermore, a higher concentration of TNF-alfa, IL-6, MIP1b, and IL-4 was observed within the pregnant COVID-19+ group. Our result shows that pregnant women express immunological characteristics that potentially mediate the immune response in COVID-19.

Correlation of serum acute-phase proteins with bone repair in rabbits (Oryctolagus cuniculus) submitted to partial radio ostectomy

ABSTRACT: Bone trauma triggers an acute inflammatory response, which can alter the serum concentration of acute-phase proteins (PFA). We aimed to evaluate the effectiveness of PFA measurement as a laboratory biomarker for inflammation related to bone regeneration. A partial ostectomy of the right radius was performed on 22 young male rabbits. The complete blood count, albumin, ceruloplasmin, haptoglobin, C-reactive protein, and transferrin levels were recorded and correlated with the radiographic evolution of bone healing. Statistically the best correlations with the inflammatory process and radiological findings were reported with haptoglobin and transferrin compared to the other measured PFAs. Haptoglobin and transferrin showed a maximum peak 24 and 36 hours after surgery, respectively. Transferrin displayed signs of decrease in the first 6 hours after surgery, in advance of the leukocyte response. The measurement of acute-phase proteins proved to be viable, considering the conditions in which the present study was carried out. Among all variables studied, haptoglobin and transferrin showed best correlation with the inflammatory process of bone healing. Additional studies are needed to determine the sensitivity of acute-phase proteins as predictors of complications in the treatment of fractures.

Vi-Vaccinations Induce Heterogeneous Plasma Cell Responses That Associate With Protection From Typhoid Fever

Vi-polysaccharide conjugate vaccines are efficacious against cases of typhoid fever; however, an absolute correlate of protection is not established. In this study, we investigated the leukocyte response to a Vi-tetanus toxoid conjugate vaccine (Vi-TT) in comparison with a plain polysaccharide vaccine (Vi-PS) in healthy adults subsequently challenged with Salmonella Typhi. Immunological responses and their association with challenge outcome was assessed by mass cytometry and Vi-ELISpot assay. Immunization induced significant expansion of plasma cells in both vaccines with modest T follicular helper cell responses detectable after Vi-TT only. The Vi-specific IgG and IgM B cell response was considerably greater in magnitude in Vi-TT recipients. Intriguingly, a significant increase in a subset of IgA+ plasma cells expressing mucosal migratory markers α4β7 and CCR10 was observed in both vaccine groups, suggesting a gut-tropic, mucosal response is induced by Vi-vaccination. The total plasma cell response was significantly associated with protection against typhoid fever in Vi-TT vaccinees but not Vi-PS. IgA+ plasma cells were not significantly associated with protection for either vaccine, although a trend is seen for Vi-PS. Conversely, the IgA- fraction of the plasma cell response was only associated with protection in Vi-TT. In summary, these data indicate that a phenotypically heterogeneous response including both gut-homing and systemic antibody secreting cells may be critical for protection induced by Vi-TT vaccination.

Male mating success is related to body condition and stress-induced leukocyte response in an anuran with scramble competition

Competition among males can be a decisive factor for successful mating in anuran explosive breeders with a male-biased population sex ratio. The Yungas Red-belly Toad (Melanophryniscus rubriventris (Vellard, 1947)) is an explosive breeder where males exhibit a classic scramble competition. We studied the body size, body condition, and stress-induced leukocyte response of M. rubriventris males under natural scenarios of scramble competition. We hand-captured adult males (categorised as single, in pairs, or in mating balls) and determined their body mass and length, body condition, and their leukocyte profile. We found that males in pairs had significantly higher body mass than single males and those in mating balls. We found the highest percentage of individuals with better body condition within the paired males who showed significantly higher body condition index value than singles or those in mating balls. Amplectant males (those collected in pairs or in mating balls) had a significantly lower proportion of lymphocytes and higher neutrophil–lymphocyte ratios than singles. Amplectant males showed significantly higher proportions of neutrophils or eosinophils than singles. Our results suggest that M. rubriventris males with better body condition can be more successful in acquiring mates, although scramble competition among males can trigger a stress response.

Analysis of the Leukocyte Response in Calves Suffered from Mycoplasma bovis Pneumonia

Mycoplasma bovis is known to be a cause of chronic pneumonia in cattle. To date, the disease pathomechanism has not been fully elucidated. Leukocytes play a key role in host antimicrobial defense mechanisms. Many in vitro studies of the effect of Mycoplasma bovis (M. bovis) on leukocytes have been performed, but it is difficult to apply these results to in vivo conditions. Additionally, only a few studies on a local immune response in M. bovis pneumonia have been undertaken. In this study, the experimental calf-infection model was used to determine the effect of field M. bovis strains on changes of the peripheral blood leukocyte response, including phagocytic activity and oxygen metabolism by cytometry analyses. An additional aim was to evaluate the lung local immunity of the experimentally infected calves using immunohistochemical staining. The general stimulation of phagocytic and killing activity of peripheral blood leukocytes in response to the M. bovis infection points to upregulation of cellular antimicrobial mechanisms. The local immune response in the infected lungs was characterized by the T- and B-cell stimulation, however, most seen in the increased T lymphocyte response. Post-infection, strong expression of the antigen-presenting cells and phagocytes also confirmed the activation of lung local immunity. In this study—despite the stimulation—both the peripheral and local cellular antimicrobial mechanisms seem to appear ineffective in eliminating M. bovis from the host and preventing the specific lung lesions, indicating an ability of the pathogen to avoid the host immune response in the M. bovis pneumonia.

Both the inflammatory response and clinical outcome differ markedly between adults with pneumococcal and meningococcal meningitis in a high HIV-1 prevalent setting in sub-Saharan Africa

Outcomes from pneumococcal meningitis (PM) are worse than meningococcal meningitis (MM), particularly in settings with high HIV-1 prevalence, but the reasons are unknown. We compared inflammatory responses between PM and MM in Malawian adults.As compared to MM (n=27, 67% HIV-infected, mortality 11%), patients with PM (n=440, 84% HIV-infected, mortality 54%) were older, had strikingly lower CSF WCC, higher pro-inflammatory cytokine concentrations and higher mortality. PM is characterized by significantly lower CSF WCC, but greater inflammation and higher mortality compared to MM. Mechanistic understanding of blunting of the CSF leukocyte response in PM in-vivo is required.