Biology subjects

Gama, L.

Publications and source records attributed to Gama, L..

3 recordsLinked to original sources

bioRxiv2022

Application of B cell immortalization for the isolation of antibodies and B cell clones from vaccine and infection settings

The isolation and characterization of neutralizing antibodies from infection and vaccine settings will inform future vaccine design, and methodologies that streamline the isolation of antibodies and the generation of B cell clones are of great interest. Retroviral transduction to express Bcl-6 and Bcl-xL in primary B cells has been shown to promote long-term B cell survival and antibody secretion in vitro, and can be used to isolate antibodies from memory B cells. The application of this methodology to B cell subsets from tissues and to B cells from individuals with chronic infection has not been extensively characterized. Here, we characterize Bcl-6/Bcl-xL B cell immortalization across multiple tissue types and B cell subsets in healthy and HIV-1 infected individuals, as well as individuals recovering from malaria. In HIV-1- and malaria-uninfected donors, naive and memory B cell subsets from PBMC and tonsil tissue transformed with similar efficiencies, and displayed similar characteristics after transformation with respect to their longevity and immunoglobulin secretion. In HIV-1-viremic individuals or in individuals after malaria infection, the CD27-CD21- memory B cell subsets transformed with lower efficiencies compared to the CD27+CD21+ populations, but following transformation B cells expanded and secreted IgG with similar efficiency. Using B cells from HIV-1-infected individuals, we combined Bcl-6/Bcl-xL B cell immortalization with a HIV-1 microneutralization assay to isolate broadly neutralizing antibodies related to VRC13 and VRC38.01. Overall, Bcl-6/Bcl-xL B cell immortalization can be used to isolate antibodies and generate B cell clones from multiple different B cell populations, albeit with different efficiencies.

immunology↗

bioRxiv2020

Social Stress Alters Immune Response and Results in Higher Viral Load During Acute SIV Infection in a Pigtailed Macaque Model of HIV

While social distancing is a key public health response during viral pandemics, social stress, which can be induced by social isolation, has been implicated in adverse health outcomes in general1 and in the context of infectious disease, such as HIV2,3. A comprehensive understanding of the direct pathophysiologic effects of social stress on viral pathogenesis is needed to provide strategic and comprehensive care to patients with viral infection. To determine the effect of social stress on HIV pathogenesis during acute viral infection without sociobehavioral confounders inherent in human cohorts, we compared commonly measured parameters of HIV progression between singly and socially housed SIV-infected pigtailed macaques (Macaca nemestrina). Singly housed macaques had a higher viral load in the plasma and cerebrospinal fluid and demonstrated greater CD4 T cell declines and greater CD4 and CD8 T cell activation compared to socially housed macaques throughout acute infection. These data demonstrate that social stress directly impacts the pathogenesis of acute HIV infection and imply that social stress may act as an integral variable in the progression of HIV infection and potentially of other viral infections.

microbiology↗

bioRxiv2018

MISSED OPPORTUNITIES OF CHLAMYDIA AND GONORRHEA DETECTION WHEN NOT USING EXTRA GENITAL SCREENING AMONG MALES

BackgroundThrough extra genital screening methods, Health Departments and community clinics can increase detection of sexually transmitted diseases (STDs) through the application of urethral testing. The Long Beach Department of Health and Human Services (LBDHHS) works on preventing cases of chlamydia (CT) and gonorrhea (GC) from being undiagnosed, by providing extra genital screening. MethodsRetrospective medical review of 1,571 patient health records, who received CT/GC testing, based on at least 1-visit to the Long Beach Department of Health & Human Services, STD Clinic, between 2012 to 2015. All male patients ages 18 years or older with positive CT/GC results (242 cases) for any of the three sites (e.g. urethral, rectal, and pharyngeal); regardless of their sexual behaviors, were included in the study. Females, those under the age of 18, and patients who tested negative for all three anatomical sites were excluded (1,412 controls). ResultsAt time of collection, study participants had a mean age of 37 years. Reported ethnicity indicated 56% Caucasian, 21% Hispanic or Latino, 9% Asian or Pacific Islander, 7% Other, 5% Black, and 2% More than one race. The use of extra genital screening detected 15% (242) of the 1,571 patients tested positive for at least 1-type of CT/GC infection. Our findings demonstrated that if urine was the only specimen collected, then over 29.7% of CT and 46.8% of GC cases would have been missed. ConclusionsTesting of all three anatomical sites should continue to be performed for CT/GC detection. Cases of CT/GC are underreported if performing urethral screening alone. These results highlight the need for clinicians to perform extra genital screening among male patients for prevention and control. These testing measures may reduce the potential for missing a diagnosis and mitigating transmission. Short SummaryThe number of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) infections missed were determined using extra genital screening procedures among male patients from the Long Beach Department of Health and Human Services (LBDHHS), STD/Family Planning Clinic. This method tests urethral, pharyngeal, and rectal sites for CT and GC infection. In this retrospective review of 1,571 patient files, of which 242 tested positive, we determined the proportion of cases that would have remained undetected if only using urethral screening.

epidemiology↗