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Herati, R.

Publications and source records attributed to Herati, R..

4 recordsLinked to original sources

Terminally Differentiated Influenza-Specific Effector Memory B Cells Circulate after Live Attenuated Influenza Vaccination

Live attenuated influenza vaccination (LAIV) is the only FDA approved mucosal vaccine. Easily assayed, circulating correlates of protection after LAIV are lacking. Using fluorochrome labeled hemagglutinin (HA) antigen, we previously identified a subset of HA-specific (HA+) IgDneg memory B cells that circulate after inactivated intramuscular vaccination (IIV), express the master transcriptional regulator, T-bet, as well as effector memory genes and predict durable antibody (Ab) responses to IIV. Here we profile the circulating HA+ IgDneg memory B cell response in a cohort of immunized patients who seroconvert after LAIV to identify which, if any, circulating HA+ B cells predict antibody responses after LAIV. Although we report LAIV elicits circulating T-bet+ HA+ IgDneg B cells that are phenotypically similar to those we described after IIV, we find no correlation between the magnitude of these cells and systemic HA-IgG responses after LAIV. Supervised and unsupervised analyses demonstrate that unlike IIV, LAIV preferentially elicits circulating HA+ IgDneg B cells that co-express TBX21 and the terminal effector cell gene, Zeb2. Consistent with their terminal differentiation status, LAIV-elicited T-bet+ cells cannot be recalled as short-lived antibody-secreting cells (ASCs) after systemic or mucosal antigen re-challenge. We conclude that the transcriptional profiles and functions of HA+ IgDneg B cells vary by influenza vaccine platform.

immunology↗

Increased resistance of SARS-CoV-2 Omicron Variant to Neutralization by Vaccine-Elicited and Therapeutic Antibodies

Currently authorized vaccines for SARS-CoV-2 have been highly successful in preventing infection and lessening disease severity. The vaccines maintain effectiveness against SARS-CoV-2 Variants of Concern but the heavily mutated, highly transmissible Omicron variant poses an obstacle both to vaccine protection and monoclonal antibody therapies. Analysis of the neutralization of Omicron spike protein-pseudotyped lentiviruses showed a 26-fold relative resistance (compared to D614G) to neutralization by convalescent sera and 26-34-fold resistance to Pfizer BNT162b2 and Moderna vaccine-elicited antibodies following two immunizations. A booster immunization increased neutralizing titers against Omicron by 6-8-fold. Previous SARS-CoV-2 infection followed by vaccination resulted in the highest neutralizing titers against Omicron. Regeneron REGN10933 and REGN10987, and Lilly LY-CoV555 and LY-CoV016 monoclonal antibodies were ineffective against Omicron, while Sotrovimab was partially effective. The results highlight the benefit of a booster immunization in providing protection against Omicron but demonstrate the challenge to monoclonal antibody therapies.

immunology↗

Neutralization of Mu and C.1.2 SARS-CoV-2 Variants by Vaccine-elicited Antibodies in Individuals With and Without Previous History of Infection

Recently identified SARS-CoV-2 variants Mu and C.1.2 have mutations in the receptor binding domain and N- and C-terminal domains that might confer resistance to natural and vaccine-elicited antibody. Analysis with pseudotyped lentiviruses showed that viruses with the Mu and C.1.2 spike proteins were partially resistant to neutralization by antibodies in convalescent sera and those elicited by mRNA and adenoviral vector-based vaccine-elicited antibodies. Virus with the C.1.2 variant spike, which is heavily mutated, was more neutralization-resistant than that of any of variants of concern. The resistance of the C.1.2 spike was caused by a combination of the RBD mutations N501Y, Y449H and E484K and the NTD mutations. Although Mu and C.1.2 were partially resistant to neutralizing antibody, neutralizing titers elicited by mRNA vaccination remained above what is found in convalescent sera and thus are likely to remain protective against severe disease. The neutralizing titers of sera from infection-experienced BNT162b2-vaccinated individuals, those with a history of previous SARS-CoV-2 infection, were as much as 15-fold higher than those of vaccinated individuals without previous infection and effectively neutralized all of the variants. The findings demonstrate that individuals can raise a broadly neutralizing humoral response by generating a polyclonal response to multiple spike protein epitopes that should protect against current and future variants.

immunology↗

Mutation of an L-Type Calcium Channel Gene Leads to a Novel Human Primary Cellular Immunodeficiency

Human primary immunodeficiencies are inherited diseases that can provide valuable insight into the immune system. Calcium (Ca2+) is a vital secondary messenger in T lymphocytes regulating a vast array of important events including maturation, homeostasis, activation, and apoptosis and can enter the cell through CRAC, TRP, and Cav channels. Here we describe three Cav1.4-deficient siblings presenting with X-linked incomplete congenital stationary night blindness as well as an immune phenotype characterized by several recurrent infections. Complete exome sequencing demonstrated that the patients share only a single pathogenic allele; a R625X (p.Arg625Ter) point mutation that leads to a premature stop codon in the CACNA1F gene encoding the L-type Ca2+ channel Cav1.4. The subjects uniformly exhibited an expansion of central and effector memory T lymphocytes, and evidence of T lymphocytes exhaustion with corresponding upregulation of inhibitory receptors. Moreover, the sustained elevated levels of activation markers on B lymphocytes suggest that they are in a chronic state of activation. Finally, the T lymphocytes from patients and CACNA1F knockdown Jurkat T lymphocytes exhibited a reduced Ca2+ flux, compared to controls. This is the first example where the mutation of any Cav channel causes a primary immunodeficiency in humans and establishes the physiological importance of Cav channels in the human immune system.

immunology↗