HIV-1 Neutralizing Antibody Signatures and Application to Epitope-Targeted Vaccine Design

Eliciting HIV-1-specific broadly neutralizing antibodies (bNAbs) remains a challenge for vaccine development, and the potential of passively delivered bNAbs for prophylaxis and therapeutics is being explored. We used neutralization data from four large virus panels to comprehensively map viral signatures associated with bNAb sensitivity, including amino acids, hypervariable region characteristics, and clade effects across four different classes of bNAbs. The bNAb signatures defined for the variable loop 2 (V2) epitope region of HIV-1 Env were then employed to inform immunogen design in a proof-of-concept exploration of signature-based epitope targeted (SET) vaccines. V2 bNAb signature-guided mutations were introduced into Env 459C to create a trivalent vaccine, and immunization of guinea pigs with V2-SET vaccines resulted in increased breadth of NAb responses compared with Env 459C alone. These data demonstrate that bNAb signatures can be utilized to engineer HIV-1 Env vaccine immunogens capable of eliciting antibody responses with greater neutralization breadth.

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HIV-1 bNAb sensitivity signatures from 4 large virus panels mapped across 4 Ab classes

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Non-contact hypervariable region characteristics are critical for bNAb sensitivity

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HIV-1 Env 459C used alone as a vaccine can elicit modest tier 2 NAbs in guinea pigs

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V2 bNAb signature-guided modifications in 459C enhanced neutralization breadth

Development of novel replication-defective lymphocytic choriomeningitis virus vectors expressing SIV antigens

An important focus in vaccine research is the design of vaccine vectors with low seroprevalence and high immunogenicity. Replication-incompetent lymphocytic choriomeningitis virus (rLCMV) vectors do not elicit vector-neutralizing antibody responses, and homologous prime-boost regimens with rLCMV vectors induce boostable and protective T cell responses to model antigens in mice. However, cellular and humoral immune responses following homologous rLCMV vaccine regimens have not been rigorously evaluated in non-human primates (NHPs). To test whether rLCMV vectors constitute an effective vaccine platform in NHPs, we developed rLCMV vectors expressing SIVmac239 Env and Gag antigens and assessed their immunogenicity in mice and cynomolgus macaques. Immunization with rLCMV vaccine vectors expressing SIV Env and Gag was effective at generating SIV-specific T cell and antibody responses in both mice and NHPs. Epitope mapping using SIV Env in C57BL/6 mice demonstrated that rLCMV vectors induced sustained poly-functional responses to both dominant and subdominant epitopes. Our results suggest the potential of rLCMV vectors as vaccine candidates. Future SIV challenge experiments in rhesus macaques will be needed to assess immune protection by these vaccine vectors.

Therapy for superficial telangiectasias of the lower extremities

A practical treatment for superficial telangiectasias of the lower extremities of described that is a modification of sclerotherapy commonly used for the treatment of varicose veins. The key to our technique lies in the use of 32-gauge needles and precise injection of small amounts of sodium tetradecyl sulfate as sclerosant. The cosmetic results of our method are good and our patients are appreciative.

Effects of size of interval between items and noise level upon immediate recall

The effect upon immediate recall of the length of the interval between auditorily presented sequences of 7 digits was studied while holding the rate of presentation constant at 1 digit per 500 msec.Ss were 144 normal-hearing young adults. An Intermediate-interval condition was created with taped naturally-spoken digits clipped each to 220 msec (interdigit interval of 280 msec). Short- and Long-interval conditions were created by expanding and compressing such digits by 33% with an AmBiChron unit, resulting in digit/interval durations of 290/210 and 150/350 msec, respectively. Digits were presented at 1 of 3 levels of white noise (no noise, -2 db, -8 db S/N). Only at the highest noise level (-8 db) S/N) did recall differ in the 3 interval conditions: recall was best in the Intermediate-interval condition and worst in the Short-interval condition. Differences were due to errors in item recall rather than to errors in order recall. These findings are inconsistent with the model of the time course of perceptual coding for immediate recall proposed by Aaronson et al. (Percept. & Psychophys., 1971, 9, 338-344.

Components of the type A coronary-prone behavior pattern and cardiovascular responses to psychomotor performance challenge

The present study tested the general hypothesis that behavioral attributes most predictive of the incidence of coronary heart disease (CHD) in epidemiological research would also be most predictive of sympathetic autonomic nervous system (ANS) arousal in response to performance challenges. Subjects (n = 50) were challenged to respond rapidly and accurately on three tasks involving either perceptual-motor or cognitive skills, while the experimenter monitored blood pressure, heart rate, and galvanic skin potential. The hypothesis was generally confirmed in that (1) type A subjects showed significantly greater cardiovascular changes indicative of sympathetic ANS arousal than type B subjects, (2) the Rosenman and Friedman structured interview was a better predictor of this arousal than the Jenkins Activity Survey, as is the case in CHD, and (3) the stylistic and behavioral components of the type A pattern (as defined by the structured interview) which are most predictive of CHD were also found to be the best predictors of challenge-induced sympathetic ANS arousal. The implications of these results for refinements in the definition, assessment, and modification of coronary-prone behavior are discussed.

Physiologic reactions to social challenge in persons evidencing the type A coronary-prone behavior pattern

Physiologic measures were recorded in Type A1 (n = 10) and Type B (n = 14) subjects while they engaged in a reaction-time task after receiving instructions emphasizing the need for rapid and accurate performance. Although resting levels were not significantly different, Type A's responded with significantly greater increases than B's in both heart rate and systolic blood pressure, suggesting greater sympathetic arousal. A significant baseline difference between the Types in heart rate variability was also observed suggesting greater lability in sympathetic-parasympathetic function in Type A's. No differences between the Types were obtained for either galvanic skin potential (GSP) or speed of reaction. It is suggested that the paradigm used in the present study offers an inexpensive and efficient means by which cardiovascular reactivity in Type A's and B's may be explored in other and larger groups of subjects.

Effects of altitude acclimatization on blood composition of women

The effects of altitude acclimatization on blood composition were studied in eight University of Missouri (elev 700 ft) coeds who lived on the summit of Pikes Peak (elev 14,000 ft) for 10 weeks. During the period of altitude exposure the following changes were observed: a transient increase in heart rate, the maximum being reached on 1st day of exposure; an early rapid increase in hematocrit and hemoglobin which later became more gradual; an early and sustained reduction in plasma volume; a rapid initial increase and a more gradual later increase in plasma protein concentration which was attributable to elevations in both the albumin and the globulin fractions; a sustained decrease in the albumin-to-globulin ratio; a slight but sustained increase in serum oncotic pressure; a slight but sustained decrease in blood water content and serum osmolarity; and finally, an unaltered total leukocyte count, but a significant increase in lymphocytes and significant decrease in monocytes. It is concluded that the hematopoietic response to altitude is markedly less in women than that usually observed in men. In women at least, dietary iron supplementation enhances the rate of hematocrit increase at altitude. And finally, the loss of plasma volume is felt to be real and not due to simple dehydration.

high altitude; hypoxia; blood volume; blood hydration; plasma proteins; hematopoiesis; leukocytes; sex differences; iron supplement

Submitted on April 3, 1968