Avidities of human monoclonal antibodies derived from an adult immunized with pneumococcal polysaccharide vaccine

Plant based vaccines provide an instructive opportunity for immunologists. We have developed a plantbasedoral vaccine against verocytotoxin–producing E. coli (VTEC) in piglets (Rossi et. al 2014). Weengineered two independent lines of Nicotiana tabacum plants for the seed-specific expression of VTECantigens, represented by the major subunit FedA of the F18 adhesive fimbriae and the B-subunit of VT2etoxin respectively (Rossi et. al. 2013). Edible vaccines in particular are of interest as they are able tostimulate the mucosal immune system to produce secretory IgA (S-IgA) at mucosal surfaces and,potentially IgG in the blood. The quality of the antibodies, such as avidity, should be considered inevaluating the efficacy of these vaccines. To develop this area, we determined avidity (strength ofantibody-antigen binding) of IgG to the capsule of another mucosal pathogen, Streptococcuspneumoniae. Using pneumococcal capsule-specific IgG human monoclonal antibodies (hMAb) clonedfrom single cells of a subject immunized with pneumococcal vaccine, we defined serotypes specificityand the avidity of these antibodies with ammonium thiocyanate (0, 4M, 2M, 1M 0.5M 0.025M)dissociation. IgG with lower avidity to the capsule are dissociated at lower NH4SCN levels, whereas IgGwith higher affinity require higher levels. We identified a range of avidities for 11 hMAB’s (range X-YMNH4SCN). We will evaluate the avidity of antibodies after immunization with edible vaccines againstVTEC strain in piglets about which little in known, but as demonstrated in Granoff et al. the high-avidityantibodies are required in generating a more effective vaccine

Avidities of human monoclonal antibodies derived from an adult immunized with pneumococcal polysaccharide vaccine

Plant based vaccines provide an instructive opportunity for immunologists. We have developed a plantbasedoral vaccine against verocytotoxin–producing E. coli (VTEC) in piglets (Rossi et. al 2014). Weengineered two independent lines of Nicotiana tabacum plants for the seed-specific expression of VTECantigens, represented by the major subunit FedA of the F18 adhesive fimbriae and the B-subunit of VT2etoxin respectively (Rossi et. al. 2013). Edible vaccines in particular are of interest as they are able tostimulate the mucosal immune system to produce secretory IgA (S-IgA) at mucosal surfaces and,potentially IgG in the blood. The quality of the antibodies, such as avidity, should be considered inevaluating the efficacy of these vaccines. To develop this area, we determined avidity (strength ofantibody-antigen binding) of IgG to the capsule of another mucosal pathogen, Streptococcuspneumoniae. Using pneumococcal capsule-specific IgG human monoclonal antibodies (hMAb) clonedfrom single cells of a subject immunized with pneumococcal vaccine, we defined serotypes specificityand the avidity of these antibodies with ammonium thiocyanate (0, 4M, 2M, 1M 0.5M 0.025M)dissociation. IgG with lower avidity to the capsule are dissociated at lower NH4SCN levels, whereas IgGwith higher affinity require higher levels. We identified a range of avidities for 11 hMAB’s (range X-YMNH4SCN). We will evaluate the avidity of antibodies after immunization with edible vaccines againstVTEC strain in piglets about which little in known, but as demonstrated in Granoff et al. the high-avidityantibodies are required in generating a more effective vaccine

Avidities of human monoclonal antibodies derived from an adult immunized with pneumococcal polysaccharide vaccine

Plant based vaccines provide an instructive opportunity for immunologists. We have developed a plantbasedoral vaccine against verocytotoxin–producing E. coli (VTEC) in piglets (Rossi et. al 2014). Weengineered two independent lines of Nicotiana tabacum plants for the seed-specific expression of VTECantigens, represented by the major subunit FedA of the F18 adhesive fimbriae and the B-subunit of VT2etoxin respectively (Rossi et. al. 2013). Edible vaccines in particular are of interest as they are able tostimulate the mucosal immune system to produce secretory IgA (S-IgA) at mucosal surfaces and,potentially IgG in the blood. The quality of the antibodies, such as avidity, should be considered inevaluating the efficacy of these vaccines. To develop this area, we determined avidity (strength ofantibody-antigen binding) of IgG to the capsule of another mucosal pathogen, Streptococcuspneumoniae. Using pneumococcal capsule-specific IgG human monoclonal antibodies (hMAb) clonedfrom single cells of a subject immunized with pneumococcal vaccine, we defined serotypes specificityand the avidity of these antibodies with ammonium thiocyanate (0, 4M, 2M, 1M 0.5M 0.025M)dissociation. IgG with lower avidity to the capsule are dissociated at lower NH4SCN levels, whereas IgGwith higher affinity require higher levels. We identified a range of avidities for 11 hMAB’s (range X-YMNH4SCN). We will evaluate the avidity of antibodies after immunization with edible vaccines againstVTEC strain in piglets about which little in known, but as demonstrated in Granoff et al. the high-avidityantibodies are required in generating a more effective vaccine

Corynebacterium species inhibit Streptococcus pneumoniae colonization and infection of the mouse airway

The stability and composition of the airway microbiome is an important determinant of respiratory health. Some airway bacteria are considered to be beneficial due to their potential to impede the acquisition and persistence of opportunistic bacterial pathogens such a

Divergent Humoral Responses to 23-Valent Pneumococcal Polysaccharide Vaccine in Critically-Ill Burn and Neurosurgical Patients

INTRODUCTION: Critically ill hospitalized patients are at increased risk of infection so we assessed the immunogenicity of 23-valent pneumococcal polysaccharide vaccine (PPSV23) administered within six days of injury. METHODS: This prospective observational study compared the immunogenicity of PPSV23 among critically ill burn and neurosurgical patients at a tertiary, academic medical center. Patients received PPSV23 vaccination within six days of ICU admission per standard of care. Consent was obtained to measure concentrations of vaccine-specific IgG to 14 of 23 serotype capsule-specific IgG in serum prior to and 14-35 days following PPSV23. A successful immunologic response was defined as both a ≥2-fold rise in capsule-specific IgG from baseline and concentrations of \u3e1 mcg/mL to 10 of 14 measured vaccine serotypes. Immunologic response was compared between burn and neurosurgical patients. Multiple variable regression methods were used to explore associations of clinical and laboratory parameters to immunologic responses. RESULTS: Among the 16 burn and 27 neurosurgical patients enrolled, 87.5% and 40.7% generated a successful response to the vaccine, respectively (p = 0.004). Both median post-PPSV23 IgG concentrations (7.79 [4.56-18.1] versus 2.93 [1.49-8.01] mcg/mL; p = 0.006) and fold rises (10.66 [7.44-14.56] versus 3.48 [1.13-6.59]; p CONCLUSION: Critically ill burn patients can generate successful responses to PPSV23 during acute injury whereas responses among neurosurgical patients is comparatively blunted. Further study is needed to elucidate the mechanisms of differential antigen responsiveness in these populations, including the role of acute stress responses, as well as the durability of these antibody responses

Clinical Features and Serum Biomarkers in HIV Immune Reconstitution Inflammatory Syndrome after Cryptococcal Meningitis: A Prospective Cohort Study

David Boulware and colleagues investigate clinical features in a prospective cohort with AIDS and recent cryptococcal meningitis after initiation of antiretroviral therapy to identify biomarkers for prediction and diagnosis of CM-IRIS (cryptococcal meninigitis-related immune reconstitution inflammatory syndrome)

HIV-Associated Cryptococcal Immune Reconstitution Inflammatory Syndrome Is Associated with Aberrant T Cell Function and Increased Cytokine Responses.

Cryptococcal meningitis remains a significant opportunistic infection among HIV-infected patients, contributing 15-20% of HIV-related mortality. A complication of initiating antiretroviral therapy (ART) following opportunistic infection is immune reconstitution inflammatory syndrome (IRIS). IRIS afflicts 10-30% of HIV-infected patients with cryptococcal meningitis (CM), but its immunopathogenesis is poorly understood. We compared circulating T cell memory subsets and cytokine responses among 17 HIV-infected Ugandans with CM: 11 with and 6 without CM-IRIS. At meningitis diagnosis, stimulation with cryptococcal capsule component, glucuronoxylomannan (GXM) elicited consistently lower frequencies of CD4+ and CD8+ T cell memory subsets expressing intracellular cytokines (IL-2, IFN-γ, and IL-17) among subjects who subsequently developed CM-IRIS. After ART initiation, T cells evolved to show a decreased CD8+ central memory phenotype. At the onset of CM-IRIS, stimulation more frequently generated polyfunctional IL-2+/IL-17+ CD4+ T cells in patients with CM-IRIS. Moreover, CD8+ central and effector memory T cells from CM-IRIS subjects also demonstrated more robust IL-2 responses to antigenic stimulation vs. controls. Thus, ART during CM elicits distinct differences in T cell cytokine production in response to cryptococcal antigens both prior to and during the development of IRIS, suggesting an immunologic foundation for the development of this morbid complication of CM infection

Monocyte Phenotype and IFN-γ-Inducible Cytokine Responses Are Associated with Cryptococcal Immune Reconstitution Inflammatory Syndrome.

A third of adults with AIDS and cryptococcal meningitis (CM) develop immune reconstitution inflammatory syndrome (IRIS) after initiating antiretroviral therapy (ART), which is thought to result from exaggerated inflammatory antigen-specific T cell responses. The contribution of monocytes to the immunopathogenesis of cryptococcal IRIS remains unclear. We compared monocyte subset frequencies and immune responses in HIV-infected Ugandans at time of CM diagnosis (IRIS-Baseline) for those who later developed CM-IRIS, controls who did not develop CM-IRIS (Control-Baseline) at CM-IRIS (IRIS-Event), and for controls at a time point matched for ART duration (Control-Event) to understand the association of monocyte distribution and immune responses with cryptococcal IRIS. At baseline, stimulation with IFN-γ ex vivo induced a higher frequency of TNF-α- and IL-6-producing monocytes among those who later developed IRIS. Among participants who developed IRIS, ex vivo IFN-γ stimulation induced higher frequencies of activated monocytes, IL-6⁺, TNF-α⁺ classical, and IL-6⁺ intermediate monocytes compared with controls. In conclusion, we have demonstrated that monocyte subset phenotype and cytokine responses prior to ART are associated with and may be predictive of CM-IRIS. Larger studies to further delineate innate immunological responses and the efficacy of immunomodulatory therapies during cryptococcal IRIS are warranted

Lactation and neonatal nutrition: defining and refining the critical questions.

This paper resulted from a conference entitled "Lactation and Milk: Defining and refining the critical questions" held at the University of Colorado School of Medicine from January 18-20, 2012. The mission of the conference was to identify unresolved questions and set future goals for research into human milk composition, mammary development and lactation. We first outline the unanswered questions regarding the composition of human milk (Section I) and the mechanisms by which milk components affect neonatal development, growth and health and recommend models for future research. Emerging questions about how milk components affect cognitive development and behavioral phenotype of the offspring are presented in Section II. In Section III we outline the important unanswered questions about regulation of mammary gland development, the heritability of defects, the effects of maternal nutrition, disease, metabolic status, and therapeutic drugs upon the subsequent lactation. Questions surrounding breastfeeding practice are also highlighted. In Section IV we describe the specific nutritional challenges faced by three different populations, namely preterm infants, infants born to obese mothers who may or may not have gestational diabetes, and infants born to undernourished mothers. The recognition that multidisciplinary training is critical to advancing the field led us to formulate specific training recommendations in Section V. Our recommendations for research emphasis are summarized in Section VI. In sum, we present a roadmap for multidisciplinary research into all aspects of human lactation, milk and its role in infant nutrition for the next decade and beyond

Cellular immune activation in cerebrospinal fluid from ugandans with cryptococcal meningitis and immune reconstitution inflammatory syndrome.

BACKGROUND: Human immunodeficiency virus (HIV)-associated cryptococcal meningitis (CM) is characterized by high fungal burden and limited leukocyte trafficking to cerebrospinal fluid (CSF). The immunopathogenesis of CM immune reconstitution inflammatory syndrome (IRIS) after initiation of antiretroviral therapy at the site of infection is poorly understood. METHODS: We characterized the lineage and activation status of mononuclear cells in blood and CSF of HIV-infected patients with noncryptococcal meningitis (NCM) (n = 10), those with CM at day 0 (n = 40) or day 14 (n = 21) of antifungal therapy, and those with CM-IRIS (n = 10). RESULTS: At diagnosis, highly activated CD8(+) T cells predominated in CSF in both CM and NCM. CM-IRIS was associated with an increasing frequency of CSF CD4(+) T cells (increased from 2.2% to 23%; P = .06), a shift in monocyte phenotype from classic to an intermediate/proinflammatory, and increased programmed death ligand 1 expression on natural killer cells (increased from 11.9% to 61.6%, P = .03). CSF cellular responses were distinct from responses in peripheral blood. CONCLUSIONS: After CM, T cells in CSF tend to evolve with the development of IRIS, with increasing proportions of activated CD4(+) T cells, migration of intermediate monocytes to the CSF, and declining fungal burden. These changes provide insight into IRIS pathogenesis and could be exploited to more effectively treat CM and prevent CM-IRIS