The presence of serum anti-SARS-CoV-2 IgA appears to protect primary health care workers from COVID-19.

The patterns of humoral and cellular responses to SARS-CoV-2 were studied in Swedish primary health care workers (n = 156) for 6 months during the Covid-19 pandemic. Serum IgA and IgG to SARS-CoV-2, T-cell proliferation and cytokine secretion, demographic and clinical data, PCR-verified infection, and self-reported symptoms were monitored. The multivariate method OPLS-DA was used to identify immune response patterns coupled to protection from Covid-19. Contracting Covid-19 was associated with SARS-CoV-2-specific neutralizing serum IgG, T cell, IFN-γ, and granzyme B responses to SARS-CoV-2, self-reported typical Covid-19 symptoms, male sex, higher BMI, and hypertension. Not contracting Covid-19 was associated with female sex, IgA-dominated, or no antibody responses to SARS-CoV-2, airborne allergy, and smoking. The IgG-responders had SARS-CoV-2-specific T-cell responses including a cytotoxic CD4+ T-cell population expressing CD25, CD38, CD69, CD194, CD279, CTLA-4, and granzyme B. IgA-responders with no IgG response to SARS-CoV-2 constituted 10% of the study population. The IgA responses were partially neutralizing and only seen in individuals who did not succumb to Covid-19. To conclude, serum IgG-dominated responses correlated with T-cell responses to SARS-CoV-2 and PCR-confirmed Covid-19, whereas IgA-dominated responses correlated with not contracting the infection.

Tofacitinib Treatment in Primary Herpes Simplex Encephalitis Interferes With Antiviral Response.

Tofacitinib, a Janus kinase inhibitor, is a novel immunosuppressive drug for treatment of rheumatoid arthritis. Herpes simplex virus type 1 (HSV-1) may cause encephalitis during primary infection or following reactivation from a latent state. Long-term tofacitinib treatment may increase the risk of this life-threatening condition. The aim of this study was to investigate the effect of tofacitinib on HSV-1 primary infection using a mouse model. Mice pretreated with tofacitinib were intranasally infected with a clinical strain of HSV-1 and monitored for infection severity and antiviral response. Tofacitinib treatment of HSV-1 primary infection resulted in increased viral loads and worsened clinical outcome. Furthermore, tofacitinib promoted M2 anti-inflammatory phenotype of microglia and infiltrating monocytes, as well as inhibited production of inflammatory and antiviral cytokines by macrophages in vitro. Our findings show that treatment with tofacitinib increases severity of herpes simplex encephalitis in mice, by impairing antiviral response induced by monocytes and microglia.

Long-Term Follow-Up of Newborns with 22q11 Deletion Syndrome and Low TRECs.

BACKGROUND: Population-based neonatal screening using T-cell receptor excision circles (TRECs) identifies infants with profound T lymphopenia, as seen in cases of severe combined immunodeficiency, and in a subgroup of infants with 22q11 deletion syndrome (22q11DS). PURPOSE: To investigate the long-term prognostic value of low levels of TRECs in newborns with 22q11DS. METHODS: Subjects with 22q11DS and low TRECs at birth (22q11Low, N=10), matched subjects with 22q11DS and normal TRECs (22q11Normal, N=10), and matched healthy controls (HC, N=10) were identified. At follow-up (median age 16 years), clinical and immunological characterizations, covering lymphocyte subsets, immunoglobulins, TRECs, T-cell receptor repertoires, and relative telomere length (RTL) measurements were performed. RESULTS: At follow-up, the 22q11Low group had lower numbers of naïve T-helper cells, naïve T-regulatory cells, naïve cytotoxic T cells, and persistently lower TRECs compared to healthy controls. Receptor repertoires showed skewed V-gene usage for naïve T-helper cells, whereas for naïve cytotoxic T cells, shorter RTL and a trend towards higher clonality were found. Multivariate discriminant analysis revealed a clear distinction between the three groups and a skewing towards Th17 differentiation of T-helper cells, particularly in the 22q11Low individuals. Perturbations of B-cell subsets were found in both the 22q11Low and 22q11Normal group compared to the HC group, with larger proportions of naïve B cells and lower levels of memory B cells, including switched memory B cells. CONCLUSIONS: This long-term follow-up study shows that 22q11Low individuals have persistent immunologic aberrations and increased risk for immune dysregulation, indicating the necessity of lifelong monitoring. CLINICAL IMPLICATIONS: This study elucidates the natural history of childhood immune function in newborns with 22q11DS and low TRECs, which may facilitate the development of programs for long-term monitoring and therapeutic choices.

CD8+ T cells in the central nervous system of mice with herpes simplex infection are highly activated and express high levels of CCR5 and CXCR3.

Herpes simplex virus type 2 (HSV-2) is a neurotropic virus that can cause meningitis, an inflammation of the meninges in the central nervous system. T cells are key players in viral clearance, and these cells migrate from peripheral blood into the central nervous system upon infection. Several factors contribute to T cell migration, including the expression of chemokines in the inflamed tissue that attract T cells through their expression of chemokine receptors. Here we investigated CD8+ T cell profile in the spinal cord in a mouse model of herpes simplex virus type 2 neuroinflammation. Mice were infected with HSV-2 and sacrificed when showing signs of neuroinflammation. Cells and/or tissue from spinal cord, spleen, and blood were analyzed for expression of activation markers, chemokine receptors, and chemokines. High numbers of CD8+ T cells were present in the spinal cord following genital HSV-2-infection. CD8+ T cells were highly activated and HSV-2 glycoprotein B -specific effector cells, some of which showed signs of recent degranulation. They also expressed high levels of many chemokine receptors, in particular CCR2, CCR4, CCR5, and CXCR3. Investigating corresponding receptor ligands in spinal cord tissue revealed markedly increased expression of the cognate ligands CCL2, CCL5, CCL8, CCL12, and CXCL10. This study shows that during herpesvirus neuroinflammation anti-viral CD8+ T cells accumulate in the CNS. CD8+ T cells in the CNS also express chemotactic receptors cognate to the chemotactic gradients in the spinal cord. This indicates that anti-viral CD8+ T cells may migrate to infected areas in the spinal cord during herpesvirus neuroinflammation in response to chemotactic gradients.

The mucosal adjuvant effect of alpha-galactosylceramide for induction of protective immunity to sexually transmitted viral infection.

Development of mucosal adjuvants to generate immunity in the female genital tract may have important implications for the development of vaccines to counter sexually transmitted infections. alpha-Galactosylceramide (alpha-GalCer) is presented by CD1d molecule on APCs to invariant Valpha14(+) NKT (iNKT) cells, which upon activation rapidly produce large amounts of immunomodulatory cytokines, leading to activation of a variety of innate and adaptive immune cells. Here, we assessed whether alpha-GalCer could act as a mucosal adjuvant for induction of protective immunity against genital herpes. We found that intranasal immunization with HSV-2 glycoprotein D (gD) in combination with alpha-GalCer elicits strong systemic gD-specific IgG Ab response as well as lymphoproliferative response with a mixed Th1/Th2 cytokine profile in the spleen, mediastinal lymph nodes, and genital lymph nodes. Importantly, such an immunization scheme conferred complete protection against an otherwise lethal vaginal HSV-2 challenge. We could also show that intravaginal immunization with gD plus alpha-GalCer generates potent gD-specific lymphoproliferative and IFN-gamma responses in the genital lymph nodes and spleen. Furthermore, the vaginally immunized mice developed a strong systemic and mucosal IgG Ab response and protection against vaginal HSV-2 challenge. The mucosal adjuvant effect of alpha-GalCer was found to be mediated via CD1d molecule and appeared to be independent of the usage of the adaptor molecule MyD88. To our knowledge, this is the first report on the mucosal adjuvant effect of alpha-GalCer for induction of protective immunity against a sexually transmitted pathogen.

Fas/FasL Contributes to HSV-1 Brain Infection and Neuroinflammation.

The Fas/FasL pathway plays a key role in immune homeostasis and immune surveillance. In the central nervous system (CNS) Fas/FasL is involved in axonal outgrowth and adult neurogenesis. However, little is known about the role of the Fas/FasL pathway in herpes encephalitis. In this study, we used a neuropathogenic clinical strain of herpes simplex virus type 1 (HSV-1) to explore infection-induced inflammation and immune responses in the mouse brain and the role of Fas/FasL in antiviral CNS immunity. HSV-1 CNS infection induced the infiltration of Fas- FasL-bearing monocytes and T cells in the brain and also to an up-regulation of Fas and FasL expression on resident astrocytes and microglia within infected sites. Upon infection, Fas- and FasL-deficient mice (lpr and gld) were partially protected from encephalitis with a decreased morbidity and mortality compared to WT mice. Fas/FasL deficiency promoted cell-mediated immunity within the CNS. Fas receptor stimulation abrogated HSV-1 induced activation and inflammatory reactions in microglia from WT mice, while lack of Fas or FasL led to a more pronounced activation of monocytes and microglia and also to an enhanced differentiation of these cells into a pro-inflammatory M1 phenotype. Furthermore, the specific immune system was more efficient in Fas- and FasL-deficient mice with significantly higher numbers of infiltrating HSV-1-specific cytotoxic T cells in the brain. Our data indicate that the Fas/FasL pathway leads to excessive neuroinflammation during HSV-1 infection, which is associated with a diminished anti-viral response and an excessive neuroinflammation.

Extracts of Equisetum giganteum L and Copaifera reticulate Ducke show strong antiviral activity against the sexually transmitted pathogen herpes simplex virus type 2.

ETHNOPHARMACOLOGICAL RELEVANCE: Equisetum giganteum L and Copaifera reticulate Ducke have been traditionally used by women of the Tacana tribe in the Bolivian Amazonas for genital hygiene and for treatment of genital infection/inflammation. AIM OF THE STUDY: To assess the ability of extracts from Equisetum giganteum L and Copaifera reticulate Ducke to block genital viral infection by herpes simplex virus type 2. MATERIALS AND METHODS: Equisetum giganteum L and Copaifera reticulate Ducke were collected from the Amazon region of La Paz, Bolivia. Extracts were prepared and screened for anti-viral activity against herpes simplex virus type 2 (HSV-2) using both in vitro and in in vivo models of infection. RESULTS: Equisetum giganteum L and Copaifera reticulate Ducke efficiently blocked HSV-2 infection of cell cultures without major cell cytotoxic effects. Extracts of Equisetum giganteum L and Copaifera reticulate Ducke could prevent HSV-2 disease development when administered together with virus in a mouse model of genital HSV-2 infection. In vitro analyses revealed that both plant extracts exerted their anti-HSV-2 effects by interfering with viral cell attachment and entry, but could not block viral replication post entry. CONCLUSIONS: These studies show that extracts of Equisetum giganteum L and Copaifera reticulate Ducke have potent antiviral activities against HSV-2 comparable to those two previously identified plants, Croton lechleri Müll. Arg. and Uncaria tomentosa (Willd. ex Schult.) DC. These studies confirm that plants used by the Tacana tribe could be explored further for the development of novel topical antiviral microbicides.

Nasal Immunization Confers High Avidity Neutralizing Antibody Response and Immunity to Primary and Recurrent Genital Herpes in Guinea Pigs.

Genital herpes is one of the most prevalent sexually transmitted infections in both the developing and developed world. Following infection, individuals experience life-long latency associated with sporadic ulcerative outbreaks. Despite many efforts, no vaccine has yet been licensed for human use. Herein, we demonstrated that nasal immunization with an adjuvanted HSV-2 gD envelope protein mounts significant protection to primary infection as well as the establishment of latency and recurrent genital herpes in guinea pigs. Nasal immunization was shown to elicit specific T cell proliferative and IFN-γ responses as well as systemic and vaginal gD-specific IgG antibody (Ab) responses. Furthermore, systemic IgG Abs displayed potent HSV-2 neutralizing properties and high avidity. By employing a competitive surface plasmon resonance (SPR) analysis combined with a battery of known gD-specific neutralizing monoclonal Abs (MAbs), we showed that nasal immunization generated IgG Abs directed to two major discontinuous neutralizing epitopes of gD. These results highlight the potential of nasal immunization with an adjuvanted HSV-2 envelope protein for induction of protective immunity to primary and recurrent genital herpes.

Thymic exosomes promote the final maturation of thymocytes.

Extensive knowledge has been gained the last years concerning mechanisms underlying the selection of single positive thymocytes in the thymic medulla. Less is known regarding other important processes in the thymic medulla such as the regulation of late stage thymocyte maturation. We have previously reported that exosomes are abundant in the thymus with a phenotype that indicates an epithelial cell origin and immunoregulatory properties. In this study we use an in vitro system to investigate the effects of thymic exosomes on the maturation of single positive thymocytes as well as effects on nTreg formation. We show that thymic exosomes promote the maturation of single positive CD4+CD25- cells into mature thymocytes with S1P1+Qa2+ and CCR7+Qa2+ phenotypes. Furthermore, we show that thymic exosomes reduce the formation of CD4+CD25+FoxP3+ thymocytes and that these exosome effects are independent of dendritic cell co-stimulation but require intact exosomal RNA content and surface proteins. An efficient direct uptake of exosomes by both thymocytes and thymic DC's is also demonstrated. In conclusion, this study demonstrates that exosomes may represent a new route of communication within the thymus.

Nasal and skin delivery of IC31(®)-adjuvanted recombinant HSV-2 gD protein confers protection against genital herpes.

Genital herpes caused by herpes simplex virus type 2 (HSV-2) remains the leading cause of genital ulcers worldwide. Given the disappointing results of the recent genital herpes vaccine trials in humans, development of novel vaccine strategies capable of eliciting protective mucosal and systemic immune responses to HSV-2 is urgently required. Here we tested the ability of the adjuvant IC31(®) in combination with HSV-2 glycoprotein D (gD) used through intranasal (i.n.), intradermal (i.d.), or subcutaneous (s.c.) immunization routes for induction of protective immunity against genital herpes infection in C57BL/6 mice. Immunization with gD plus IC31(®) through all three routes of immunization developed elevated gD-specific serum antibody responses with HSV-2 neutralizing activity. Whereas the skin routes promoted the induction of a mixed IgG2c/IgG1 isotype profile, the i.n. route only elicited IgG1 antibodies. All immunization routes were able to induce gD-specific IgG antibody responses in the vaginas of mice immunized with IC31(®)-adjuvanted gD. Although specific lymphoproliferative responses were observed in splenocytes from mice of most groups vaccinated with IC31(®)-adjuvanted gD, only i.d. immunization resulted in a significant splenic IFN-γ response. Further, immunization with gD plus IC31(®) conferred 80-100% protection against an otherwise lethal vaginal HSV-2 challenge with amelioration of viral replication and disease severity in the vagina. These results warrant further exploration of IC31(®) for induction of protective immunity against genital herpes and other sexually transmitted infections.

Unraveling molecular signatures of immunostimulatory adjuvants in the female genital tract through systems biology.

Sexually transmitted infections (STIs) unequivocally represent a major public health concern in both industrialized and developing countries. Previous efforts to develop vaccines for systemic immunization against a large number of STIs in humans have been unsuccessful. There is currently a drive to develop mucosal vaccines and adjuvants for delivery through the genital tract to confer protective immunity against STIs. Identification of molecular signatures that can be used as biomarkers for adjuvant potency can inform rational development of potent mucosal adjuvants. Here, we used systems biology to study global gene expression and signature molecules and pathways in the mouse vagina after treatment with two classes of experimental adjuvants. The Toll-like receptor 9 agonist CpG ODN and the invariant natural killer T cell agonist alpha-galactosylceramide, which we previously identified as equally potent vaginal adjuvants, were selected for this study. Our integrated analysis of genome-wide transcriptome data determined which signature pathways, processes and networks are shared by or otherwise exclusive to these 2 classes of experimental vaginal adjuvants in the mouse vagina. To our knowledge, this is the first integrated genome-wide transcriptome analysis of the effects of immunomodulatory adjuvants on the female genital tract of a mammal. These results could inform rational development of effective mucosal adjuvants for vaccination against STIs.

La gD2 coadministrada con el AFCo1 por vía intranasal induce inmunidad protectora contra virus de herpes simple tipo 2 en ratones / gD2 coadministered with AFCo1 by intranasal route induces protective immunity against Virus Herpes Simplex type 2 in mice

La infección por virus herpes simple tipo 2 (VHS-2) continúa siendo un problema de salud mundial. Esta infección es transmitida sexualmente y es la principal causa de úlceras genitales. La prevención de esta enfermedad requiere de la utilización de vacunas mucosales, pues las vacunas parenterales no han sido exitosas. Por otra parte, no existen adyuvantes mucosales, por lo que el desarrollo de estos es esencial para la estrategia de estas vacunas. La administración intranasal (IN) de la glicoproteína D del VHS-2 (gD2), coadministrada con el cocleato (AFCo1+gD2) sería igualmente efectiva con la gD2 incluida (AFCo1-gD2). Se inocularon ratones hembras C57BL/6 por la vía IN con gD2, contenida dentro del cocleato, coadministrada con el cocleato o gD2 sola. Se determinaron los niveles de IgG anti gD2 en suero y lavado vaginal, así como las subclases de IgG anti gD2 por ELISA. Se determinó la respuesta linfoproliferativa en células de bazo, el perfil de citoquinas Th1/Th2, los signos de la enfermedad y la protección frente al reto viral. Se observaron altos títulos de IgG e IgG2c anti gD2 en el suero de los animales inoculados con la gD2 y el AFCo1 como adyuvante. No se observaron diferencias significativas (p>0,05) entre los grupos que recibieron AFCo1+gD2 y los que recibieron AFCo1-gD2. Se observó un perfil de citoquinas tipo Th1 y un 100 por ciento de sobrevida en los grupos que recibieron el AFCo1 como adyuvante de la gD2, mientras que en el grupo que recibió la gD2 sola no se observó protección. Estos resultados indican que la gD2 puede ser utilizada coadministrada con AFCo1 por vía IN como un potencial candidato vacunal contra VHS-2(AU)

Sexually transmitted infections by Herpes Simplex Virus type 2 (HSV-2) are the leading cause of genital ulcers and a major public health problem worldwide. This requires the use of mucosal vaccines, because parenteral vaccines have not been successful. Presently, there are not mucosal adjuvants, for this reason the development of adjuvants is essential for mucosal vaccine strategies. The intranasal (IN) immunizations using HSV-2 glycoprotein D (gD2), coadministered with cochleate (AFCo1+gD2), would be an efficient candidate for future vaccines against HSV2, similar to the gD2 incorporated into AFCo1(AFCo1-gD2). Female C57Bl/6 mice were inoculated with AFCo1-gD2, AFCo1+gD2 or gD2 alone by IN route. The anti gD2 IgG in sera and vaginal fluids and IgG subclasses were measured by ELISA. The lymphoproliferative response in spleen cells, the Th1/Th2 cytokine profile, the protection and the signs of disease against viral challenge were measured. High titers of IgG and IgG2c subclasses were observed in sera of mice that received the gD2 and AFCo1 as adjuvant. No significant differences (p>0.005) were observed in the animals that received AFCo1+gD2 or AFCo1-gD2. a preferential Th1 cytokine profile and 100 percent of survival after challenge were observed in both groups that received the gD2 and AFCo1, while no survival was observed in the group that only received the gD2. These results showed that the gD2 can be used coadministered with AFCo1 by IN route as a potential vaccine candidate against HSV-2(AU)

Influencia de las vías de inmunización mucosales sobre la protección contra herpes simple tipo 2 con el AFCo1 como adyuvante / Influence of mucosal immunization routes on herpes simplex virus type 2 protection with AFCol as adjuvant

Las vacunas mucosales se han planteado como una estrategia prometedora para inducir protección mucosal. El virus herpes simple tipo 2 es uno de los patógenos más frecuentes en el humano transmitidos por vía sexual. Varios candidatos vacunales contra este patógeno se han evaluado, pero no han sido efectivos, por lo que aún no se cuenta con una vacuna profiláctica ni terapéutica. La gD2 es una glicoproteína recombinante y está reportada como uno de los antígenos de importancia vacunal contra este germen. Contamos con el cocleato derivado del proteoliposoma de Neisseria meningitidis serogrupo B (AFCo1) que ha mostrado capacidades adyuvantes por varias vías de inmunización. El objetivo de este trabajo fue evaluar la protección inducida en ratones por el AFCo1-gD2, administrada por diferentes vías mucosales. Se utilizaron ratones hembras C57BL6, los cuales fueron inmunizados por vía intranasal (IN), intravaginal (IVag) o intrarrectal (IR) con AFCo1-gD2 o gD2 sola. Se determinó la IgG anti gD2, la proliferación celular específica, la replicación viral en lavado vaginal, los signos de la enfermedad y la protección frente al reto viral. Se obtuvo respuestas significativas de IgG anti gD2 por todas las vías, aunque la IN mostró los valores más elevados. Se observó proliferación celular en células de animales inmunizados IN e IVag, pero no por vía IR. Se observó la mayor protección (100 por ciento) en los animales inmunizados por vía IN. Se concluye que la vía nasal es la más prometedora en la inducción de protección contra este reto viral(AU)

Mucosal vaccines are a promising strategy to induce mucosal protection. Herpes simplex virus type 2 is the commonest pathogens in the human transmitted by exposure at the genital mucosal surfaces. Many vaccine candidates against this pathogen have been evaluated; but they have not been effective, and neither a prophylactic nor a therapeutic vaccine has been yet obtained. The gD2 is a recombinant glycoprotein and it is reported as one of the antigens of importance for vaccine against this virus. There is the cochleate (AFCo1) derived from proteoliposome of Neisseria meningitidis serogroup B. This cochleate has shown potentialities as adjuvant for several immunization routes. The objective of this study was to evaluate the protection induced in mice by the AFCo1-gD2 administered by different mucosal routes. Female mice C57BL/6 were used and immunized by: intranasal (IN), intravaginal (IVag), or intrarectal (IR) routes with AFCo1-gD2 or gD2 alone. The anti-gD2 IgG and specific cellular proliferation were determined and the viral replication in vaginal wash, the signs of disease and the protection against the viral challenge, were measured too. A significant anti-gD2 IgG response was obtained by all routes, although the IN route showed the highest values. Cellular proliferation was observed in cells of animals immunized IN and IVag route; but not by IR route. In addition, a higher protection (100 percent) in the animals immunized with AFCo1-gD2 by IN route was observed. In conclusion the intranasal is the most promising route in the protection induction against this viral challenge(AU)