Seed-transmission of Cowpea mild mottle virus on several varieties of soybean in Indonesia

Sutrawati M, Hidayat SH, Suastika G, Sukarno BPW, Nurmansyah A. 2021. Seed-transmission of Cowpea mild mottle virus on several varieties of soybean in Indonesia. Biodiversitas 22: 4182-4185. Seeds and infected plants play important role as source of disease in the field for seed-transmitted virus, such as Cowpea mild mottle virus (CPMMV). Research was conducted to determine seed transmission nature of CPMMV on 10 soybean varieties based on growing on test method and dot immunobinding assay to confirm CPMMV infection. Field experiment was conducted to evaluate the efficiency of seed-transmitted CPMMV as the source of initial inoculum in the field. Soybean var. ‘Anjasmoro’ from 3 cultivation areas (Cianjur, Bogor, and Cirebon) was used for field experiment. Seed transmission of CPMMV was confirmed on soybean var. ‘Detam 2’, ‘Detam 3’, ‘Malika’, ‘Anjasmoro’, and ‘Argomulyo’; but was not found on ‘Detam 1’, ‘Detam 4’, ‘Wilis’, ‘Grobogan’, and ‘Dena 1’. The infection of CPMMV did not show symptom, either on the seedcoat and the unifoliolate leaves. Infection rate of CPMMV on seeds were relatively high, ranged between 27 to 86%. Disease incidence on var. ‘Anjasmoro’ from Cianjur, Cirebon, and Bogor varied from 32.9 to 75% and 57.9 to 81.3% in screenhouse and field experiment, respectivelly.

Continuous HIV-1 Escape from Autologous Neutralization and Development of Cross-Reactive Antibody Responses Characterizes Slow Disease Progression of Children

The antibodies with different effector functions evoked by Human Immunodeficiency Virus type 1 (HIV-1) transmitted from mother to child, and their role in the pathogenesis of infected children remain unresolved. So, too, the kinetics and breadth of these responses remain to be clearly defined, compared to those developing in adults. Here, we studied the kinetics of the autologous and heterologous neutralizing antibody (Nab) responses, in addition to antibody-dependent cellular cytotoxicity (ADCC), in HIV-1 infected children with different disease progression rates followed from close after birth and five years on. Autologous and heterologous neutralization were determined by Peripheral blood mononuclear cells (PBMC)- and TZMbl-based assays, and ADCC was assessed with the GranToxiLux assay. The reactivity to an immunodominant HIV-1 gp41 epitope, and childhood vaccine antigens, was assessed by ELISA. Newborns displayed antibodies directed towards the HIV-1 gp41 epitope. However, antibodies neutralizing the transmitted virus were undetectable. Nabs directed against the transmitted virus developed usually within 12 months of age in children with slow progression, but rarely in rapid progressors. Thereafter, autologous Nabs persisted throughout the follow-up of the slow progressors and induced a continuous emergence of escape variants. Heterologous cross-Nabs were detected within two years, but their subsequent increase in potency and breadth was mainly a trait of slow progressors. Analogously, titers of antibodies mediating ADCC to gp120 BaL pulsed target cells increased in slow progressors during follow-up. The kinetics of antibody responses to the immunodominant viral antigen and the vaccine antigens were sustained and independent of disease progression. Persistent autologous Nabs triggering viral escape and an increase in the breadth and potency of cross-Nabs are exclusive to HIV-1 infected slowly progressing children.

Vector Competence of Peruvian Mosquitoes for Two Orthobunyaviruses Isolated From Mosquitoes Captured in Peru

We evaluated the potential for mosquitoes collected in the Amazon Basin, near Iquitos, Peru, to become infected with and transmit Murutucu (MURV) and Itaqui viruses (ITQV) (Order Bunyavirales, Family: Peribunyaviridae, Genus: Orthobunyavirus). Viremia levels in Syrian hamsters peaked 2 d after infection with either virus, and both viruses were highly lethal in hamsters with virtually all hamsters dying prior to 3-d postinfection. For almost all of the mosquito species tested some individuals were susceptible to infection and some developed a disseminated infection after oral exposure to either MURV or ITQV. However, only the Culex species (Culex (Culex) coronator Dyar and Knab [Diptera, Culicidae], Culex (Melanoconian) gnomatos Sallum, Huchings, and Ferreira [Diptera, Culicidae], Culex (Mel.) pedroi Sirivanakarn and Belkin [Diptera, Culicidae], and Culex (Mel.) vomerifer Komp [Diptera, Culicidae]) successfully transmitted virus by bite. However, even among these species, only about 37% of the individuals with a disseminated infection successfully transmitted these viruses, indicating a significant salivary gland barrier. Although little is known about the medical or veterinary importance of many members of the genus Orthobunyavirus, we have demonstrated that Culex spp. (Diptera, Culicidae) could be potential vectors.

COVID-19: Structure, Replication and Its Global Scenario

Background:: The disease which have led the whole world in lockdown state. Coronavirus are highly transmitted virus which is spreading in whole world by an intensive speed. Introduction:: Novel coronavirus, termed as COVID-19 is an RNA genome comprising spherical spiked structure, which can infect human by majorly attacking on respiratory system. The infection is characterized by high fever, dry cough and fatigue. The purpose of this review to main characteristics feature of COVID-19, the symptoms, the genetic material present in the virus. The review also focuses the uniqueness of this virus form other viruses, which are making a troubler for developing the vaccine. Discussion and Conclusion:: The review illustrated the number of people affected by COVID 19 in the whole world with special case of India. Analysis have shown that how vast COVID- 19 have affected the human beings.

Diversity and Function of Maternal HIV-1-Specific Antibodies at the Time of Vertical Transmission

ABSTRACT Infants of HIV-positive mothers can acquire HIV infection by various routes, but even in the absence of antiviral treatment, the majority of these infants do not become infected. There is evidence that maternal antibodies provide some protection from infection, but gestational maternal antibodies have not yet been characterized in detail. One of the most studied vertically infected infants is BG505, as the virus from this infant yielded an Envelope protein that was successfully developed as a stable trimer. Here, we isolated and characterized 39 HIV-specific neutralizing monoclonal antibodies (nAbs) from MG505, the mother of BG505, at a time point just prior to vertical transmission. These nAbs belonged to 21 clonal families and employed a variety of VH genes. Many were specific for the HIV-1 Env V3 loop, and this V3 specificity correlated with measurable antibody-dependent cellular cytotoxicity (ADCC) activity. The isolated nAbs did not recapitulate the full breadth of heterologous or autologous virus neutralization by contemporaneous plasma. Notably, we found that the V3-targeting nAb families neutralized one particular maternal Env variant, even though all tested variants had low V3 sequence diversity and were measurably bound by these nAbs. None of the nAbs neutralized BG505 transmitted virus. Furthermore, the MG505 nAb families were found at relatively low frequencies within the maternal B cell repertoire; all were less than 0.25% of total IgG sequences. Our findings illustrate an example of the diversity of HIV-1 nAbs within one mother, cumulatively resulting in a collection of antibody specificities that can contribute to the transmission bottleneck. IMPORTANCE Mother-to-child-transmission of HIV-1 offers a unique setting in which maternal antibodies both within the mother and passively transferred to the infant are present at the time of viral exposure. Untreated HIV-exposed human infants are infected at a rate of 30 to 40%, meaning that some infants do not get infected despite continued exposure to virus. Since the potential of HIV-specific immune responses to provide protection against HIV is a central goal of HIV vaccine design, understanding the nature of maternal antibodies may provide insights into immune mechanisms of protection. In this study, we isolated and characterized HIV-specific antibodies from the mother of an infant whose transmitted virus has been well studied.

Diversity and function of maternal HIV-1-specific antibodies at the time of vertical transmission

Infants of HIV positive mothers can acquire HIV infection by various routes, but even in the absence of antiviral treatment, the majority of these infants do not become infected. There is evidence that maternal antibodies may provide some protection from infection, but gestational maternal antibodies have not yet been characterized in detail. One of the most studied vertically-infected infants is BG505, as the virus from this infant yielded an Envelope protein that was successfully developed as a stable trimer. Here, we isolated and characterized 39 HIV-specific neutralizing monoclonal antibodies (nAbs) from MG505, the mother of BG505, at a time point just prior to vertical transmission. These nAbs belonged to 21 clonal families, employed a variety of VH genes, many were specific for the HIV-1 Env V3 loop, and this V3 specificity correlated with measurable antibody-dependent cellular cytotoxicity (ADCC) activity. The isolated nAbs did not recapitulate the full breadth of heterologous nor autologous virus neutralization by contemporaneous plasma. Notably, we found that the V3-targeting nAb families neutralized one particular maternal Env variant even though all tested variants had low V3 sequence diversity and were measurably bound by these nAbs. None of the nAbs neutralized the BG505 transmitted virus. Furthermore, the MG505 nAb families were found at relatively low frequencies within the maternal B cell repertoire: all less than 0.25% of total IgG sequences. Our findings demonstrate the diversity of HIV-1 nAbs that exist within a single mother, resulting in a collection of antibody specificities that can shape the transmission bottleneck.ImportanceMother-to-child-transmission of HIV-1 offers a unique setting in which maternal antibodies both within the mother and passively-transferred to the infant are present at the time of viral exposure. Untreated HIV-exposed human infants are infected at a rate of 30-40%, meaning that some infants do not get infected despite continued exposure to virus. Since the potential of HIV-specific immune responses to provide protection against HIV is a central goal of HIV vaccine design, understanding the nature of maternal antibodies may provide insights into immune mechanisms of protection. In this study, we isolated and characterized HIV-specific antibodies from the mother of an infant whose transmitted virus has been well studied.

Low Replication Capacity Virus is Preferentially Transmitted in Mother-to-Child-Transmission but not in Adult-to-Adult-Transmission of HIV-1

ABSTRACTPrevious studies of the transmitted/founder virus compared to viral quasispecies in the donor have yielded conflicting results. In heterosexual adult-to-adult transmission (ATAT), the viral replicative capacity (VRC) of transmitted virus is reportedly either similar to, or somewhat higher than, that of donor virus, whilst transmitted virus in mother-to-child transmission (MTCT) has a significantly lower VRC than that of maternal virus. These discrepancies may be explained by the different methodologies used in these studies, or they may reflect true differences in the transmission bottleneck. To resolve this question, we here use the same methodology to compare transmitted versus donor virus in MTCT and ATAT. We show that, in a South African mother-child cohort, infant virus samples obtained at 1-2 days after birth had VRC significantly lower than in the mothers (p=0.0003). By contrast, in Zambian ATAT transmission pairs, VRC of transmitted virus was similar to or somewhat higher than donor virus (p=ns). The VRC of virus transmitted to the recipient, compared to that in the donor, was significantly lower in MTCT versus heterosexual ATAT (p=0.01). These studies demonstrate that fundamental differences exist between the viruses transmitted via the MTCT and ATAT bottlenecks that are not explained by methodological factors. This result is of importance since transmission of low replicative capacity virus results in low immune activation and a small viral reservoir, and therefore the preferential transmission of low fitness viruses in MTCT might be expected to increase cure potential in in utero infected infants and children.IMPORTANCEUnderstanding the factors determining which viruses are preferentially transmitted in HIV infection is critical to the development of new, effective strategies to prevent transmission. Despite this, much remains unknown in this respect, both with regard to adult-to-adult transmission (ATAT) but especially with respect to mother-to-child transmission (MTCT). The finding here that fundamental differences exist in the genetic bottleneck of HIV transmission between heterosexual ATAT and MTCT is an important initial step to help define the viral mechanisms contributing to transmission in each case. In addition, we show that viruses of low viral replicative capacity are preferentially transmitted in MTCT. This suggests the possibility that a window of opportunity exists following in utero infection in which early anti-viral intervention not only reduces the size and diversity of the viral reservoir, but additionally maintains a reservoir comprising low viral replicative capacity HIV. Low replicative capacity of transmitted virus has previously been shown to result in low immune activation and low proviral DNA load in central memory cells, factors likely to be directly relevant to increasing cure potential in HIV-infected infants and children.